New Tool (new + tool)

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  • Selected Abstracts

    Protein-Based Capacitive Biosensors: a New Tool for Structure-Activity Relationship Studies

    ELECTROANALYSIS, Issue 24 2008
    Alessia Mortari
    Abstract The present work reports a new application of a protein-based capacitive biosensor as an in vitro assay for the selectivity study of the bacterial periplasmic protein MerP and four MerP variants. The modified MerP proteins were produced by site-directed mutagenesis of the heavy metal associated motif (HMA). The MerP and modified MerPs selectivity for copper, zinc, cadmium and mercury bivalent ions were investigated and compared. The variations in the proteins affinity were related to the primary structure of the HMA motifs. Key amino acids for copper coordination of metalloproteins that contain the metal binding sequence Gly-Met-Thr-Cys-xxx-xxx-Cys were identified. The results brought insights valid for Menkes and Wilson ATPases. The protein-based capacitive biosensors were a simple and useful tool for studying structure-activity relationships of proteins. [source]

    Two-Dye Core/Shell Zeolite Nanoparticles: A New Tool for Ratiometric pH Measurements

    Tristan Doussineau
    Abstract The preparation of core/shell nanoparticles that enable ratiometric pH measurement is described. The core of the nanoparticles consists of a zeolite- , matrix that exhibits a 3-hydroxyflavone reference dye within the porous network. Coating an amorphous silica shell containing a fluorosensor around the zeolite through the Stöber process provides pH sensitivity to the nanoparticles. Morphological characterization (dynamic light scattering, transmission electronic microscopy) demonstrates the control of the sensing silica shell around the zeolite cores, leading to highly monodisperse spherical nanoparticles, while structural characterization (wide-angle X-ray diffraction, nitrogen adsorption) shows the amorphous character of the shell. Spectral characterization via UV/Vis absorption and steady-state fluorescence shows good pH sensitivity of the resulting nanosensors with a pKa suitable for bioanalytical applications. [source]

    The Trophic Index of Macrophytes (TIM) , a New Tool for Indicating the Trophic State of Running Waters

    Susanne Schneider
    Abstract In running waters, apart from structural degradation, nutrient input becomes increasingly important. To investigate the indicator values of as many species of submerged macrophytes as possible numerous samples of the sediment within macrophyte stands and the overlying water were taken in running waters throughout Bavaria, Germany. To develop the Trophic Index of Macrophytes (TIM), the concentrations of soluble reactive phosphorus of both the water body and the sediment pore water were used. Based on a weighted sum of the SRP-concentrations of the water body and the sediment pore water, indicator values were determined for a total of 49 species of submerged macrophytes. A detailed method is described on how and depending on which preconditions the trophic state of running waters can be determined by the TIM. An example of the TIM in the stream Rotbach is given. It shows that the TIM is a useful means to detect differences in the phosphorus loading of running waters. [source]

    Functional Magnetic Resonance Imaging in Conscious Animals: A New Tool in Behavioural Neuroscience Research

    C. F. Ferris
    First page of article [source]

    The School Health Portfolio System: A New Tool for Planning and Evaluating Coordinated School Health Programs

    Robert M. Weiler
    ABSTRACT: The School Health Portfolio System (SHPS), developed originally to evaluate the Florida Coordinated School Health Program Pilot Schools Project, offers a new and innovative system for planning and evaluating a coordinated school health program at the individual school level. The SHPS provides practitioners a detailed but easy-to-use system that enables schools to create new programs or modify existing programs across all eight components of the CSHP model, as well as administrative support critical to sustainability. The System comes packaged as a self-contained, notebook-style manual divided into 15 sections. It includes electronic templates of key documents to guide school teams in creating a customized portfolio, and a list of sample goals and artifacts that confirm achievement of a goal related to the school's coordinated school health program. An evaluation rubric provides a structured method to assess a program portfolio's contents, and the extent to which the contents document achievement of program goals. The rubric produces both a qualitative assessment, such as a narrative summary of program strengths and areas for improvement, and a quantitative assessment, such as a numerical score (0,100), letter grade (A-F), or 5-star system (* - *****). The physical structure, function, and scoring of the rubric depend on the method of assessment. The SHPS enables schools to set goals based on individual school needs, and incorporate CSHP goals into school improvement plans - a critical factor in sustainability and accountability. The System also offers teams the option of coordinating their efforts with CDC's School Health Index as a companion assessment measure. This article outlines the process a team would follow in developing a portfolio, and includes a sample assessment for the area of School Health Education. (J Sch Health. 2004;74(9):359,364) [source]

    Bedside Transthoracic Sonography in Suspected Pulmonary Embolism: A New Tool for Emergency Physicians

    Beatrice Hoffmann MD
    First page of article [source]

    Geographic Information Systems: A New Tool for Environmental Health Assessments

    Mona Choi
    ABSTRACT Objectives: (1) To develop tools for health care professionals and communities to assess environmental exposures and (2) to evaluate the utility of integrating patient-reported environmental health information with geographic information systems (GIS) mapping of environmental data in a pilot study. Methods: A survey was used to collect self-reported environmental exposure and health data from a convenience sample of people at an urban community health center (N=101). Environmental exposure and census information were obtained from federal agencies. Analysis was performed using descriptive statistics and GIS. Results: Frequent environmental health risk factors were reported, such as older housing (93%) and household smoking (78%). Health problems including asthma (54%) and lead poisoning (14%) were reported. Odds ratios indicated a statistically significant relationship between mold/mildew and reporting asthma. GIS was found to be a useful tool in displaying environmental risk factors and potentially associated health effects. Conclusions: Given the important role that environmental health risks can play in public health, it is critical that community/public health nurses begin to integrate environmental health assessment skills into their professional practices. Simple community surveys can be an effective means to raise awareness about environmental health risk factors and utilizing GIS can further enhance the accessibility of the combined exposure and health information. [source]

    Google Moderator, a New Tool for Public Deliberation

    Masahiro Matsuura

    Analytic Models of Domain-Averaged Fermi Holes: A New Tool for the Study of the Nature of Chemical Bonds

    Robert Ponec Prof.
    Abstract Simple analytical models are introduced that significantly enhance the ability to understand and rationalise the nature of bonding interactions depicted by domain-averaged Fermi hole (DAFH) analysis. The examples presented show that besides shedding new light on the role of electron-sharing in ordinary two-centre two-electron (2c,2e) chemical bonds that are well represented by the classical Lewis model, the proposed approach also provides interesting new insights into the nature of bonding interactions that go beyond the traditional Lewis paradigm. This is, for example, the case of 3c,2e multicentre bonding, but a straightforward extension of the approach also reveals for direct metal,metal bonding the existence of a completely new type of bonding interaction that involves the mutual exchange of electrons between the lone pairs on adjacent metal atoms. [source]

    Psychology, Psychiatry, and Brain Neuroscience in Pain Medicine: New Tools for a New Science

    PAIN MEDICINE, Issue 8 2008
    Ajay Wasan MD
    No abstract is available for this article. [source]

    Towards a decision support system for health promotion in nursing

    Kate Caelli PhD RN RM
    Aims. This study was designed to investigate what type of models, techniques and data are necessary to support the development of a decision support system for health promotion practice in nursing. Specifically, the research explored how interview data can be interpreted in terms of Concept Networks and Bayesian Networks, both of which provide formal methods for describing the dependencies between factors or variables in the context of decision-making in health promotion. Background. In nursing, the lack of generally accepted examples or guidelines by which to implement or evaluate health promotion practice is a challenge. Major gaps have been identified between health promotion rhetoric and practice and there is a need for health promotion to be presented in ways that make its attitudes and practices more easily understood. New tools, paradigms and techniques to encourage the practice of health promotion would appear to be beneficial. Concept Networks and Bayesian Networks are techniques that may assist the research team to understand and explicate health promotion more specifically and formally than has been the case, so that it may more readily be integrated into nursing practice. Methods. As the ultimate goal of the study was to investigate ways to use the techniques described above, it was necessary to first generate data as text. Textual descriptions of health promotion in nursing were derived from in-depth qualitative interviews with nurses nominated by their peers as expert health promoting practitioners. Findings. The nurses in this study gave only general and somewhat vague outlines of the concepts and ideas that guided their practice. These data were compared with descriptions from various sources that describe health promotion practices in nursing, then examples of a Conceptual Network and a representative Bayesian Network were derived from the data. Conclusions. The study highlighted the difficulty in describing health promotion practice, even among nurses recognized for their expertise in health promotion. Nevertheless, it indicated the data collection and analysis methods necessary to explicate the cognitive processes of health promotion and highlighted the benefits of using formal conceptualization techniques to improve health promotion practice. [source]

    Technology, security, and individual privacy: New tools, new threats, and new public perceptions

    Lee S. Strickland
    Highly portable information collection and transmission technologies such as radio frequency identification (RFID) tags and smart cards are becoming ubiquitous in government and business,employed in functions including homeland security, information security, physical premises security, and even the control of goods in commerce. And, directly or indirectly, in many of these applications, it is individuals and their activities that are tracked. Yet, a significant unknown is (a) whether the public understands these technologies and the manner in which personally identifiable information may be collected, maintained, used, and disseminated; and (b) whether the public consents to these information practices. To answer these and related questions, we surveyed a select group of citizens on the uses of this technology for business as well as homeland security purposes. We found a significant lack of understanding, a significant level of distrust even in the context of homeland security applications, and a very significant consensus for governmental regulation. We conclude that a primary objective for any organization deploying these technologies is the promulgation of a comprehensive Technology Privacy Policy, and we provide detailed specifications for such an effort. [source]

    New tools for resolving phylogenies: a systematic revision of the Convolutidae (Acoelomorpha, Acoela)

    M. D. Hooge
    Abstract Molecular sequence data, morphological characters of spermatozoa, and newly obtained morphological characters of penis musculature are used here to revise the systematics of the family Convolutidae (Acoela). Species having isodiametric penes with non-anastomosing longitudinal muscles are transferred to the family Isodiametridae fam. nov. Species with longitudinal penis muscle fibres that anastomose or cross-over each other remain in the Convolutidae. Some species of the genera Convoluta and Conaperta (Convolutidae) are transferred to the genus Isodiametra gen. nov. (Isodiametridae fam. nov.). The genus Stomatricha (Otocelididae) is transferred to the family Convolutidae. Convoluta opisthandropora (Convolutidae) is transferred to the genus Pseudohaplogonaria (Haploposthiidae). Aphanostoma sanguineum (Convolutidae) is transferred to the genus Pseudactinoposthia (Actinoposthiidae). Zusammenfassung Molekulare Sequenzdaten, Spermien-Morphologie und erstmals ermittelte morphologische Merkmale der Penismuskulatur werden herangezogen, um die Verwandtschaftsverhältnisse innerhalb der Familie Convolutidae (Acoela) neu zu beleuchten. Dabei werden Arten mit isodiametrischen Penes mit nicht anastomosierender Längsmuskulatur in die neue Familie Isodiametridae gestellt, während Arten mit longitudinalen Penis-Muskelfasern, die sich verbunden oder einanderüberkreuzen, innerhalb der Convolutidae belassen. Einige Arten der Gattungen Convoluta und Conaperta (Convolutidae) werden in die neue Gattung Isodiametra gen. nov. (Isodametridae fam. nov.) gestellt. Die Gattung Stomatricha (Otocelididae) wird in die Familie Convolutidae überführt. Convoluta opisthandropora (Convolutidae) wird in die Gattung Pseudohaplogonaria (Haploposthiidae) gestellt und Aphanostoma sanguineum (Convolutidae) in die Gattung Pseudactinoposthia (Actinoposthiidae). [source]

    Diff(Rn) as a Milnor,Lie group

    Helge Glöckner
    Abstract We describe a construction of the Lie group structure on the diffeomorphism group Diff(Rn), modelled on the space D(Rn,Rn) of Rn -valued test functions on Rn, in John Milnor's setting of infinite-dimensional Lie groups. New tools are introduced to simplify this task. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Mycoviruses of filamentous fungi and their relevance to plant pathology

    SUMMARY Mycoviruses (fungal viruses) are reviewed with emphasis on plant pathogenic fungi. Based on the presence of virus-like particles and unencapsidated dsRNAs, mycoviruses are common in all major fungal groups. Over 80 mycovirus species have been officially recognized from ten virus families, but a paucity of nucleic acid sequence data makes assignment of many reported mycoviruses difficult. Although most of the particle types recognized to date are isometric, a variety of morphologies have been found and, additionally, many apparently unencapsidated dsRNAs have been reported. Until recently, most characterized mycoviruses have dsRNA genomes, but ssRNA mycoviruses now constitute about one-third of the total. Two hypotheses for the origin of mycoviruses of plant pathogens are discussed: the first that they are of unknown but ancient origin and have coevolved along with their hosts, the second that they have relatively recently moved from a fungal plant host into the fungus. Although mycoviruses are typically readily transmitted through asexual spores, transmission through sexual spores varies with the host fungus. Evidence for natural horizontal transmission has been found. Typically, mycoviruses are apparently symptomless (cryptic) but beneficial effects on the host fungus have been reported. Of more practical interest to plant pathologists are those viruses that confer a hypovirulent phenotype, and the scope for using such viruses as biocontrol agents is reviewed. New tools are being developed based on host genome studies that will help to address the intellectual challenge of understanding the fungal,virus interactions and the practical challenge of manipulating this relationship to develop novel biocontrol agents for important plant pathogens. [source]

    New tools for labeling silica in living diatoms

    NEW PHYTOLOGIST, Issue 3 2008
    Julien Desclés
    Summary ,,Silicon biomineralization is a widespread mechanism found in several kingdoms that concerns both unicellular and multicellular organisms. As a result of genomic and molecular tools, diatoms have emerged as a good model for biomineralization studies and have provided most of the current knowledge on this process. However, the number of techniques available to study its dynamics at the cellular level is still rather limited. ,,Here, new probes were developed specifically to label the pre-existing or the newly synthesized silica frustule of several diatoms species. ,,It is shown that the LysoTracker Yellow HCK-123, which can be used to visualize silica frustules with common filter sets, presents an enhanced signal-to-noise ratio and allows details of the frustules to be imaged without of the use of ionophores. It is also demonstrated that methoxysilane derivatives can be coupled to fluorescein-5-isothiocyanate (FITC) to preferentially label the silica components of living cells. ,,The coupling of labeling procedures might help to address the challenging question of the process of frustule exocytosis. [source]

    Mosquito repellents: a review of chemical structure diversity and olfaction

    Gretchen Paluch
    Abstract Research on mosquito chemical repellents continues to advance, along with knowledge of mosquito olfaction and behavior, mosquito,host interactions and chemical structure. New tools and technologies have revealed information about insect olfactory mechanisms and processing, providing a more complex approach for the interpretation of how chemical repellents influence host-seeking and feeding behavior. Even with these advances, there is still a large amount of information contained in the early works on insect repellents. Many of the standard test methods and chemicals that are still used for evaluating active repellents were developed in the 1940s. These studies contain valuable references to the activity of different structural classes of chemicals, and serve as a guide to optimization of select compounds for insect repellency effects. Copyright © 2010 Society of Chemical Industry [source]

    New tools for single nucleotide polymorphism (SNP) discovery and analysis accelerating plant biotechnology

    Robert Henry
    No abstract is available for this article. [source]

    Australian tropical forest canopy crane: New tools for new frontiers

    AUSTRAL ECOLOGY, Issue 1 2007
    Abstract An industrial crane was installed in the Daintree lowland rainforest in 1998 to provide a new means of accessing the canopy. Approximately 0.95 ha of forest, including 680 trees of 82 species with a diameter at breast height of greater than 10 cm, are accessible using the crane. The site was hit by a Category 3 Cyclone in 1999 and has shown a remarkable rate of recovery. The crane has been used for a very wide range of research including tree physiology and ecology, interactions with vertebrate and invertebrate biodiversity and studies of carbon and water fluxes. Results from studies on this crane and 11 other cranes around the world are changing views of the importance of the rainforest canopy. [source]

    A web-based tool for control engineering teaching

    J. Albino Méndez
    Abstract In this article a new tool for control engineering teaching is presented. The tool was implemented using Java applets and is freely accessible through Web. It allows the analysis and simulation of linear control systems and was created to complement the theoretical lectures in basic control engineering courses. The article is not only centered in the description of the tool but also in the methodology to use it and its evaluation in an electrical engineering degree. Two practical problems are included in the manuscript to illustrate the use of the main functions implemented. The developed web-based tool can be accessed through the link © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 178,187, 2006; Published online in Wiley InterScience (; DOI 10.1002/cae.20080 [source]

    Nordic Occupational Skin Questionnaire (NOSQ-2002): a new tool for surveying occupational skin diseases and exposure

    CONTACT DERMATITIS, Issue 2 2003
    P Susitaival
    Occupational skin diseases are among the most frequent work-related diseases in industrialized countries. Good occupational skin disease statistics exist in few countries. Questionnaire studies are needed to get more data on the epidemiology of occupational skin diseases. The Nordic Occupational Skin Questionnaire Group has developed a new questionnaire tool , Nordic Occupational Skin Questionnaire (NOSQ-2002) , for surveys on work-related skin disease and exposures to environmental factors. The 2 NOSQ-2002 questionnaires have been compiled by using existing questionnaires and experience. NOSQ-2002/SHORT is a ready-to-use 4-page questionnaire for screening and monitoring occupational skin diseases, e.g. in a population or workplace. All the questions in the short questionnaire (NOSQ-2002/SHORT) are included in the long version, NOSQ-2002/LONG, which contains a pool of questions to be chosen according to research needs and tailored to specific populations. The NOSQ-2002 report includes, in addition to the questionnaires, a comprehensive manual for researchers on planning and conducting a questionnaire survey on hand eczema and relevant exposures. NOSQ-2002 questionnaires have been compiled in English and translated into Danish, Swedish, Finnish and Icelandic. The use of NOSQ-2002 will benefit research on occupational skin diseases by providing more standardized data, which can be compared between studies and countries. [source]

    Near patient blood ketone measurements and their utility in predicting diabetic ketoacidosis

    DIABETIC MEDICINE, Issue 2 2005
    S. Harris
    Abstract Aim To assess the utility of near patient blood ketone measurements in predicting diabetic ketoacidosis (DKA) among a group of hyperglycaemic unwell patients presenting to a hospital emergency department. Methods Near patient blood ,-hydroxybutyrate (,-OHB) testing has recently been introduced as a new tool in our hospital Accident and Emergency department (A&E) for patients with a finger-prick glucose of > 11 mmol/l. We reviewed the records of the first 50 patients to have a ,-OHB measurement to establish if they developed DKA or received treatment with intravenous insulin within 48 h of presentation. We then compared the diagnostic power of ,-OHB measurements with other clinical, physiological and biochemical markers of DKA. Results Nine patients had DKA, eight had a compensated metabolic acidosis secondary to raised serum ketones, and 33 had no evidence of DKA during the following 48 h. The median (range) ,-OHB levels in each group were 6.0 (3.1,6.0) mmol/l, 3.4 (1.2,5.7) mmol/l, and 0.1 (0.0,1.2) mmol/l, respectively. A ,-OHB level of , 3.0 mmol/l had a sensitivity of 100% and specificity of 88% for DKA. All those with ,-OHB level > 3.0 mmol/l required treatment with intravenous insulin. Conclusion Measuring ,-OHB when a hyperglycaemic patient is identified could offer a simple method of identifying at an early stage those patients at highest risk of DKA (,-OHB > 3.0 mmol/l), and redirecting the search for a diagnosis in others (,-OHB < 1.0 mmol/l). [source]

    Efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions,

    Yasushi Sano
    Magnifying chromoendoscopy is an exciting new tool and offers detailed analysis of the morphological architecture of mucosal crypt orifices. In this review, we principally show the efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions such as prediction between non-neoplastic lesions and neoplastic ones, and distinction between endoscopically treatable early invasive cancers and untreatable cancers based on a review of the literature and our experience at two National Cancer Centers in Japan. Overall diagnostic accuracy by conventional view, chromoendoscopy and chromoendoscopy with magnification ranged from 68% to 83%, 82% to 92%, and 80% to 96%, respectively, and diagnostic accuracy of accessing the stage of early colorectal cancer using magnifying colonoscopy was over 85%. Although the reliability depends on the skill in magnifying observation, widespread applications of the magnification technique could influence the indications for biopsy sampling during colonoscopy and the indication for mucosectomy. Moreover, the new detailed images seen with magnifying chromoendoscopy are the beginning of a new period in which new optical developments, such as narrow band imaging system, endocytoscopy system, and laser-scanning confocal microscopy, will allow a unique look at glandular and cellular structures. [source]

    DWEPP: a dynamic soil erosion model based on WEPP source terms

    N. S. Bulygina
    Abstract A new rangeland overland-flow erosion model was developed based on Water Erosion Prediction Project (WEPP) sediment source and sink terms. Total sediment yield was estimated for rainfall simulation plots from the WEPP field experiments as well as for a small watershed without a well developed channel network. Both WEPP and DWEPP gave a similar level of prediction accuracy for total event soil losses measured from both rainfall simulation and small watershed experiments. Predictions for plot and hillslope scale erosion simulations were in the range of expected natural variability. Sediment yield dynamics were plotted and compared with experimental results for plots and hillslope, and the results were satisfactory. Effects of cover and canopy on the predicted sediment yields were well represented by the model. DWEPP provides a new tool for assessing erosion rates and dynamics, has physically based erosion mechanics descriptions, is sensitive to treatment differences on the experimental plots and has a well developed parameter database inherited from WEPP. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    A novel approach to tag and identify geranylgeranylated proteins

    ELECTROPHORESIS, Issue 20 2009
    Lai N. Chan
    Abstract A recently developed proteomic strategy, the "GG-azide"-labeling approach, is described for the detection and proteomic analysis of geranylgeranylated proteins. This approach involves metabolic incorporation of a synthetic azido-geranylgeranyl analog and chemoselective derivatization of azido-geranylgeranyl-modified proteins by the "click" chemistry, using a tetramethylrhodamine-alkyne. The resulting conjugated proteins can be separated by 1-D or 2-D and pH fractionation, and detected by fluorescence imaging. This method is compatible with downstream LC-MS/MS analysis. Proteomic analysis of conjugated proteins by this approach identified several known geranylgeranylated proteins as well as Rap2c, a novel member of the Ras family. Furthermore, prenylation of progerin in mouse embryonic fibroblast cells was examined using this approach, demonstrating that this strategy can be used to study prenylation of specific proteins. The "GG-azide"-labeling approach provides a new tool for the detection and proteomic analysis of geranylgeranylated proteins, and it can readily be extended to other post-translational modifications. [source]

    MCE enzyme immunoassay for carcinoembryonic antigen and alpha-fetoprotein using electrochemical detection

    ELECTROPHORESIS, Issue 19 2009
    Shusheng Zhang
    Abstract An MCE electrochemical enzyme immunoassay protocol for the determination of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was reported. Two antigens (Ag), CEA and AFP, were incubated simultaneously with an excess amount of horseradish peroxidase-labeled antibody (Ab*). The free Ab* and the Ab*,Ag complex produced in the solution were first separated through a postcolumn reaction and then traced by the enzyme substrate o -aminophenol. The 3-aminophenoxazine produced in enzyme reaction was detected with downstream amperometric detection. The separations were performed at a separation voltage of +1.4,kV and were completed in less than 60,s. The better analytical performance and distinct miniaturization/portability for MCE at less assay time and sample volume consumption was achieved. The detection limit of CEA and AFP was calculated to be 0.25 and 0.13,ng/mL, respectively. Therefore, MCE could be used as a sensitive and new tool in separation science and offered considerable promise in biological sample analysis or quick clinical diagnosis. [source]

    Atmospheric molding of ionic copolymer MALDI-TOF/MS arrays: A new tool for protein identification/profiling

    ELECTROPHORESIS, Issue 24 2006
    Alexander Muck
    Abstract An atmospheric molding protocol has been used to prepare an ionic methacrylate-based copolymer sample support chips for MALDI (pMALDI)-MS by targeting selected groups of various monomers copolymerized during molding, namely, carboxy, sulfo, dimethylalkyamino, and trimethylalkylammonium groups. The new disposable array chips provide analyte-oriented enhancement of protein adsorption to the modified substrates without requiring complicated surface coating or derivatization. The MALDI-MS performance of the new ionic copolymer chips was evaluated for lysozyme, ,-lactoglobulin,A, trypsinogen and carbonic anhydrase,I using washing with solutions prepared in pH or ionic strength steps. On cationic chips, the proteins are washed out at pH lower than their pI values, and on anionic chips at pH higher than their pI values. The ability of the microfabricated pMALDI chip set to selectively adsorb different proteins from real samples and to significantly increase their MS-signal was documented for the transmembrane photosystem,I protein complex from the green alga Chlamydomonas reinhardtii. The proteins were almost exclusively adsorbed according to calculated pI values and grand average of hydropathy (GRAVY) indexes. The new disposable chips reduce manipulation times and increase measurement sensitivity for real-world proteomic samples. The simple atmospheric molding procedure enables additional proteomic operations to be incorporated on disposable MALDI-MS integrated platforms. [source]

    Advances in sol-gel based columns for capillary electrochromatography: Sol-gel open-tubular columns

    ELECTROPHORESIS, Issue 22-23 2002
    Abdul Malik
    Abstract The development of sol-gel open-tubular column technology in capillary electrochromatography (CEC) is reviewed. Sol-gel column technology offers a versatile means of creating organic-inorganic hybrid stationary phases. Sol-gel column technology provides a general approach to column fabrication for microseparation techniques including CEC, and is amenable to both open-tubular and monolithic columns. Direct chemical bonding of the stationary phase to the capillary inner walls provides enhanced thermal and solvent stability to sol-gel columns. Sol-gel stationary phases inherently possess higher surface area, and thus provide an effective one-step alternative to conventional open-tubular column technology. Sol-gel column technology is applicable to both silica-based and transition metal oxide-based hybrid stationary phases, and thus, provides a great opportunity to utilize advanced material properties of a wide range of nontraditional stationary phases to achieve enhanced selectivity in analytical microseparations. A wide variety of stationary phase ligands can be chemically immobilized on the capillary inner surface using a single-step sol-gel procedure. Sol-gel chemistry can be applied to design stationary phases with desired chromatographic characteristics, including the possibility of creating columns with either a positive or a negative charge on the stationary phase surface. This provides a new tool to control electroosmotic flow (EOF) in the column. Column efficiencies on the order of half a million theoretical plates per meter have been reported for sol-gel open-tubular CEC columns. The selectivity of sol-gel stationary phases can be easily fine-tuned by adjusting the composition of the coating sol solution. Open-tubular columns have significant advantages over their packed counterparts because of the simplicity in column making and hassle-free fritless operation. Open-tubular CEC columns possess low sample capacity and low detection sensitivity. Full utilization of the analytical potential of sol-gel open-tubular columns will require a concomitant development in the area of high-sensitivity detection technology. [source]

    Covert attention allows for continuous control of brain,computer interfaces

    Ali Bahramisharif
    Abstract While brain-computer interfaces (BCIs) can be used for controlling external devices, they also hold the promise of providing a new tool for studying the working brain. In this study we investigated whether modulations of brain activity by changes in covert attention can be used as a continuous control signal for BCI. Covert attention is the act of mentally focusing on a peripheral sensory stimulus without changing gaze direction. The ongoing brain activity was recorded using magnetoencephalography in subjects as they covertly attended to a moving cue while maintaining fixation. Based on posterior alpha power alone, the direction to which subjects were attending could be recovered using circular regression. Results show that the angle of attention could be predicted with a mean absolute deviation of 51° in our best subject. Averaged over subjects, the mean deviation was ,70°. In terms of information transfer rate, the optimal data length used for recovering the direction of attention was found to be 1700 ms; this resulted in a mean absolute deviation of 60° for the best subject. The results were obtained without any subject-specific feature selection and did not require prior subject training. Our findings demonstrate that modulations of posterior alpha activity due to the direction of covert attention has potential as a control signal for continuous control in a BCI setting. Our approach will have several applications, including a brain-controlled computer mouse and improved methods for neuro-feedback that allow direct training of subjects' ability to modulate posterior alpha activity. [source]

    Characterization of a novel NCAM ligand with a stimulatory effect on neurite outgrowth identified by screening a combinatorial peptide library

    Lars C. B. Rønn
    Abstract The neural cell adhesion molecule, NCAM, plays a key role in neural development and plasticity mediating cell adhesion and signal transduction. By screening a combinatorial library of synthetic peptides with NCAM purified from postnatal day 10 rat brains, we identified a nonapeptide, termed NCAM binding peptide 10 (NBP10) and showed by nuclear magnetic resonance analysis that it bound the NCAM IgI module of NCAM. NBP10 modulated cell aggregation as well as neurite outgrowth induced specifically by homophilic NCAM binding. Moreover, both monomeric and multimeric forms of NBP10 stimulated neurite outgrowth from primary hippocampal neurons. The neurite outgrowth response to NBP10 was inhibited by a number of compounds previously shown to inhibit neurite outgrowth induced by homophilic NCAM binding, including voltage-dependent calcium channel antagonists, suggesting that NBP10 induced neurite outgrowth by activating a signal transduction pathway similar to that activated by NCAM itself. Moreover, an inhibitor of intracellular calcium mobilization, TMB-8, prevented NBP10-induced neurite outgrowth suggesting that NCAM-dependent neurite outgrowth also requires mobilization of calcium from intracellular calcium stores in addition to calcium influx from extracellular sources. By single-cell calcium imaging we further demonstrated that NBP10 was capable of inducing an increase in intracellular calcium in PC12E2 cells. Thus, the NBP10 peptide is a new tool for the study of molecular mechanisms underlying NCAM-dependent signal transduction and neurite outgrowth, and could prove to be a useful modulator of regenerative processes in the peripheral and central nervous system. [source]