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991.
The possibility to observe microsecond dynamics at the sub-micron scale, opened by recent technological advances in fast camera sensors, will affect many biophysical studies based on particle tracking in optical microscopy. A main limiting factor for further development of fast video microscopy remains the illumination of the sample, which must deliver sufficient light to the camera to allow microsecond exposure times. Here we systematically compare the main illumination systems employed in holographic tracking microscopy, and we show that a superluminescent diode and a modulated laser diode perform the best in terms of image quality and acquisition speed, respectively. In particular, we show that the simple and inexpensive laser illumination enables less than s camera exposure time at high magnification on a large field of view without coherence image artifacts, together with a good hologram quality that allows nm-tracking of microscopic beads to be performed. This comparison of sources can guide in choosing the most efficient illumination system with respect to the specific application. 相似文献
992.
Xavier Janssens Saskia Decuman Filip De Keyser the Belgian Rheumatoid Arthritis Disability Assessment study group 《PloS one》2014,9(9)
Objective
This study investigated whether the Health Assessment Questionnaire (HAQ) can be used as an instrument to assess the need for social support measures that address activity limitations and participation issues in patients with rheumatoid arthritis (RA).Methods
This multicenter observational study included patients with RA and disease duration of at least one year, consulting their rheumatologist for routine evaluation of disease activity. In the single study visit data on demographics, disease history and current treatment were collected. DAS28 values were collected to evaluate current RA disease activity. Patients were asked to fill out the HAQ and SF-36 questionnaires. Receiver Operator Characteristics (ROC) curves were constructed to evaluate the performance of the HAQ, SF-36 and DAS28 in predicting the need for nine supporting measures available for chronically ill patients in the Belgian social security system. The expert opinion of the treating rheumatologist was used as a reference.Results
The study included 316 patients with a mean age of 59.8±12.6 years, disease duration of 11.4±9.3 years, mean DAS28 values of 2.83±1.17. Mean HAQ score was 0.95±0.73, mean SF-36 score 56.5±21.3. HAQ scores >1 were observed in 39.4% of patients. The area under the HAQ ROC curve was consistently >0.7 and higher for the HAQ than for SF-36 or DAS28 for all support measures. Rheumatologists on average recommended 3.67 support measures.Conclusion
The HAQ score was found to be a good predictor of the need for social support measures in patients with RA. 相似文献993.
Marine Guillaud-Bataille Bruno Ragazzon Aurélien de Reyniès Claire Chevalier Isabelle Francillard Olivia Barreau Virginie Steunou Johann Guillemot Frédérique Tissier Marthe Rizk-Rabin Fernande René-Corail Abir Al Ghuzlan Guillaume Assié Xavier Bertagna Eric Baudin Yves Le Bouc Jér?me Bertherat Eric Clauser 《PloS one》2014,9(8)
994.
Seth Stapleton Michelle LaRue Nicolas Lecomte Stephen Atkinson David Garshelis Claire Porter Todd Atwood 《PloS one》2014,9(7)
Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high density of bears during the summer ice-free season. Bears were distinguished from other light-colored spots by comparing images collected on different dates. A sample of ground-truthed points demonstrated that we accurately classified bears. Independent observers reviewed images and a population estimate was obtained using mark–recapture models. This estimate (: 94; 95% Confidence Interval: 92–105) was remarkably similar to an abundance estimate derived from a line transect aerial survey conducted a few days earlier (: 102; 95% CI: 69–152). Our findings suggest that satellite imagery is a promising tool for monitoring polar bears on land, with implications for use with other Arctic wildlife. Large scale applications may require development of automated detection processes to expedite review and analysis. Future research should assess the utility of multi-spectral imagery and examine sites with different environmental characteristics. 相似文献
995.
Xavier Méndez José P. Espada Mireia Orgilés Luis M. Llavona José M. García-Fernández 《PloS one》2014,9(7)
This study describes the psychometric properties of the Children''s Separation Anxiety Scale (CSAS), which assesses separation anxiety symptoms in childhood. Participants in Study 1 were 1,908 schoolchildren aged between 8 and 11. Exploratory factor analysis identified four factors: worry about separation, distress from separation, opposition to separation, and calm at separation, which explained 46.91% of the variance. In Study 2, 6,016 children aged 8–11 participated. The factor model in Study 1 was validated by confirmatory factor analysis. The internal consistency (α = 0.82) and temporal stability (r = 0.83) of the instrument were good. The convergent and discriminant validity were evaluated by means of correlations with other measures of separation anxiety, childhood anxiety, depression and anger. Sensitivity of the scale was 85% and its specificity, 95%. The results support the reliability and validity of the CSAS. 相似文献
996.
Xavier Solé Marta Crous-Bou David Cordero David Olivares Elisabet Guinó Rebeca Sanz-Pamplona Francisco Rodriguez-Moranta Xavier Sanjuan Javier de Oca Ramon Salazar Victor Moreno 《PloS one》2014,9(9)
Background
Accurate detection of characteristic proteins secreted by colon cancer tumor cells in biological fluids could serve as a biomarker for the disease. The aim of the present study was to identify and validate new serum biomarkers and demonstrate their potential usefulness for early diagnosis of colon cancer.Methods
The study was organized in three sequential phases: 1) biomarker discovery, 2) technical and biological validation, and 3) proof of concept to test the potential clinical use of selected biomarkers. A prioritized subset of the differentially-expressed genes between tissue types (50 colon mucosa from cancer-free individuals and 100 normal-tumor pairs from colon cancer patients) was validated and further tested in a series of serum samples from 80 colon cancer cases, 23 patients with adenoma and 77 cancer-free controls.Results
In the discovery phase, 505 unique candidate biomarkers were identified, with highly significant results and high capacity to discriminate between the different tissue types. After a subsequent prioritization, all tested genes (N = 23) were successfully validated in tissue, and one of them, COL10A1, showed relevant differences in serum protein levels between controls, patients with adenoma (p = 0.0083) and colon cancer cases (p = 3.2e-6).Conclusion
We present a sequential process for the identification and further validation of biomarkers for early detection of colon cancer that identifies COL10A1 protein levels in serum as a potential diagnostic candidate to detect both adenoma lesions and tumor.Impact
The use of a cheap serum test for colon cancer screening should improve its participation rates and contribute to decrease the burden of this disease. 相似文献997.
Christine Danel Mathieu Kabran André Inwoley Anani Badje Jean Louis Herrmann Raoul Moh Jér?me Lecarrou Delphine Gabillard Jean Baptiste Ntakpe Nina Deschamps Eric Ouattara Christian Perronne Serge Eholie Xavier Anglaret 《PloS one》2014,9(10)
Objective
To assess the performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) test for active tuberculosis (TB) in HIV adults, and its variation over time in patients on antiretroviral therapy (ART) and/or isoniazide preventive therapy (IPT).Methods
Transversal study and cohort nested in the Temprano ANRS 12136 randomized controlled trial assessing benefits of initiating ART earlier than currently recommended by World Health Organization, with or without a 6-month IPT. Performance of QFT-GIT for detecting active TB at baseline in the first 50% participants, and 12-month incidence of conversion/reversion in the first 25% participants were assessed. QFT-GIT threshold for positivity was 0.35 IU/ml.Results
Among the 975 first participants (median baseline CD4 count 383/mm3, positive QFT-GIT test 35%), 2.7% had active TB at baseline. QFT-GIT sensitivity, specificity, positive and negative predictive value for active TB were 88.0%, 66.6%, 6.5% and 99.5%. For the 444 patients with a second test at 12 months, rates for conversion and reversion were 9.3% and 14%. Reversion was more frequent in patients without ART and younger patients. IPT and early ART were not associated with reversion/conversion.Conclusion
A negative QFT-GIT could rule out active TB in HIV-infected adults not severely immunosuppressed, thus avoiding repeated TB testing and accelerating diagnosis and care for other diseases.Trial Registration
ClinicalTrials.gov . NCT00495651相似文献998.
Adriana Farias Silva Erick Leite Bastos Marcelo Der Torossian Torres André Luis Costa‐da‐Silva Rafaella Sayuri Ioshino Margareth Lara Capurro Flávio Lopes Alves Antonio Miranda Renata de Freitas Fischer Vieira Vani Xavier Oliveira Jr. 《Journal of peptide science》2014,20(8):640-648
Angiotensin II (AII) as well as analog peptides shows antimalarial activity against Plasmodium gallinaceum and Plasmodium falciparum, but the exact mechanism of action is still unknown. This work presents the solid‐phase synthesis and characterization of eight peptides corresponding to the alanine scanning series of AII plus the amide‐capped derivative and the evaluation of the antiplasmodial activity of these peptides against mature P. gallinaceum sporozoites. The Ala screening data indicates that the replacement of either the Ile5 or the His6 residues causes minor effects on the in vitro antiplasmodial activity compared with AII, i.e. AII (88%), [Ala6]‐AII (79%), and [Ala5]‐AII (75%). Analogs [Ala3]‐AII, [Ala1]‐AII, and AII‐NH2 showed antiplasmodial activity around 65%, whereas the activity of the [Ala8]‐AII, [Ala7]‐AII, [Ala4]‐AII, and [Ala2]‐AII analogs is lower than 45%. Circular dichroism data suggest that AII and the most active analogs adopt a β‐fold conformation in different solutions. All AII analogs, except [Ala4]‐AII and [Ala8]‐AII, show contractile responses and interact with the AT1 receptor, [Ala5]‐AII and [Ala6]‐AII. In conclusion, this approach is helpful to understand the contribution of each amino acid residue to the bioactivity of AII, opening new perspectives toward the design of new sporozoiticidal compounds. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
999.
Micka?l Bouvet Adrien Lugari Clara C. Posthuma Jessika C. Zevenhoven Stéphanie Bernard Stéphane Betzi Isabelle Imbert Bruno Canard Jean-Claude Guillemot Patrick Lécine Susanne Pfefferle Christian Drosten Eric J. Snijder Etienne Decroly Xavier Morelli 《The Journal of biological chemistry》2014,289(37):25783-25796
The RNA-synthesizing machinery of the severe acute respiratory syndrome Coronavirus (SARS-CoV) is composed of 16 non-structural proteins (nsp1–16) encoded by ORF1a/1b. The 148-amino acid nsp10 subunit contains two zinc fingers and is known to interact with both nsp14 and nsp16, stimulating their respective 3′-5′ exoribonuclease and 2′-O-methyltransferase activities. Using alanine-scanning mutagenesis, in cellulo bioluminescence resonance energy transfer experiments, and in vitro pulldown assays, we have now identified the key residues on the nsp10 surface that interact with nsp14. The functional consequences of mutations introduced at these positions were first evaluated biochemically by monitoring nsp14 exoribonuclease activity. Disruption of the nsp10-nsp14 interaction abrogated the nsp10-driven activation of the nsp14 exoribonuclease. We further showed that the nsp10 surface interacting with nsp14 overlaps with the surface involved in the nsp10-mediated activation of nsp16 2′-O-methyltransferase activity, suggesting that nsp10 is a major regulator of SARS-CoV replicase function. In line with this notion, reverse genetics experiments supported an essential role of the nsp10 surface that interacts with nsp14 in SARS-CoV replication, as several mutations that abolished the interaction in vitro yielded a replication-negative viral phenotype. In contrast, mutants in which the nsp10-nsp16 interaction was disturbed proved to be crippled but viable. These experiments imply that the nsp10 surface that interacts with nsp14 and nsp16 and possibly other subunits of the viral replication complex may be a target for the development of antiviral compounds against pathogenic coronaviruses. 相似文献