104 research outputs found
Facile and Low-Cost Fabrication of SiO2-Covered Au Nanoislands for Combined Plasmonic Enhanced Fluorescence Microscopy and SERS
NEDA—NEutron Detector Array
The NEutron Detector Array, NEDA, will form the next generation neutron detection system that has been designed to be operated in conjunction with γ-ray arrays, such as the tracking-array AGATA, to aid nuclear spectroscopy studies. NEDA has been designed to be a versatile device, with high-detection efficiency, excellent neutron-γ discrimination, and high rate capabilities. It will be employed in physics campaigns in order to maximise the scientific output, making use of the different stable and radioactive ion beams available in Europe. The first implementation of the neutron detector array NEDA with AGATA 1π was realised at GANIL. This manuscript reviews the various aspects of NEDA
Dopamine Signaling Is Essential for Precise Rates of Locomotion by C. elegans
Dopamine is an important neuromodulator in both vertebrates and invertebrates. We have found that reduced dopamine signaling can cause a distinct abnormality in the behavior of the nematode C. elegans, which has only eight dopaminergic neurons. Using an automated particle-tracking system for the analysis of C. elegans locomotion, we observed that individual wild-type animals made small adjustments to their speed to maintain constant rates of locomotion. By contrast, individual mutant animals defective in the synthesis of dopamine made larger adjustments to their speeds, resulting in large fluctuations in their rates of locomotion. Mutants defective in dopamine signaling also frequently exhibited both abnormally high and abnormally low average speeds. The ability to make small adjustments to speed was restored to these mutants by treatment with dopamine. These behaviors depended on the D2-like dopamine receptor DOP-3 and the G-protein subunit GOA-1. We suggest that C. elegans and other animals, including humans, might share mechanisms by which dopamine restricts motor activity levels and coordinates movement
Assessing motor-related phenotypes of Caenorhabditis elegans with the wide field-of-view nematode tracking platform
Caenorhabditis elegans is a valuable model organism in biomedical research that has led to major discoveries in the fields of neurodegeneration, cancer and aging. Because movement phenotypes are commonly used and represent strong indicators of C. elegans fitness, there is an increasing need to replace manual assessments of worm motility with automated measurements to increase throughput and minimize observer biases. Here, we provide a protocol for the implementation of the improved wide field-of-view nematode tracking platform (WF-NTP), which enables the simultaneous analysis of hundreds of worms with respect to multiple behavioral parameters. The protocol takes only a few hours to complete, excluding the time spent culturing C. elegans, and includes (i) experimental design and preparation of samples, (ii) data recording, (iii) software management with appropriate parameter choices and (iv) post-experimental data analysis. We compare the WF-NTP with other existing worm trackers, including those having high spatial resolution. The main benefits of WF-NTP relate to the high number of worms that can be assessed at the same time on a whole-plate basis and the number of phenotypes that can be screened for simultaneously
Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición
[ES] En este artículo presentamos el diseño de un nuevo escáner
PET para animales pequeños basado en una tecnología completamente
innovadora. Los resultados preliminares son muy prometedores,
permitiendo obtener imágenes funcionales de alta resolución
con una instrumentación compacta y de bajo coste. Los
prototipos desarrollados se encuentran actualmente en pruebas
en diversos centros de investigación médica, obteniéndose imá-
genes de alta calidad en los campos de oncología, neurología y
cardiología. Este diseño puede ser fácilmente extendido a cámaras
PET dedicadas a la exploración del cerebro o de la mama.
La innovación más notable de la presente tecnología consiste
en el uso de un único cristal continuo por módulo, a diferencia
de otras cámaras PET comerciales donde se utilizan cientos
de cristales pixelados. El uso de un único cristal continuo permite
abaratar el coste de fabricación, al tiempo que mejora las
características de funcionamiento: resolución intrínseca en posición
de 1,2 mm, resolución en energía media del 14%, resolución
en la profundidad de interacción de 3 mm, sensibilidad
> 4% y campo de visión transaxial de 80 mm de diámetro.
En el presente artículo se describen en detalle el diseño de esta
nueva cámara PET, los principios de funcionamiento, el método
utilizado para su calibración y se anticipan algunas imágenes
"in vivo" del miocardio y el cerebro de un ratón, permitiendo
apreciar de forma preliminar la resolución y calidad alcanzadas.[EN] In this paper we present the design of a new small animal
PET scanner based on a completely innovative technology. The
achieved results are very promising, showing the possibility to
obtain high resolution functional images with a compact and low
cost scanner. Several prototypes have been developed and are
currently being used at different research medical institutions.
High resolution images are being obtained in application fields
like oncology, neurology and cardiology. This technology can be
easily applied in PET cameras for brain or breast exploration.
The most significant innovation of the design is the fact of
using a single crystal per module instead of hundreds of pixellated
crystals as in other commercial PETs. It has the advantage
of decreasing the manufacturing costs and simultaneously
improves its performance: 1.2 mm position intrinsic resolution,
mean energy resolution as good as 14%, 3 mm depth of interaction
resolution, sensitivity above 4%, and 80 mm diameter
of transaxial field of view.
In this paper we describe in detail the design of this new
PET camera, its principle, the calibration methodology and also
some preliminary "in vivo" images of a mouse myocardium
and brain, showing the achieved image resolution and qualityBenlloch Baviera, JM.; González Martínez, AJ.; Carrilero, V.; Catret, JV.; Correcher, C.; Lerche, CW.; Morera, C.... (2007). Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición. Revista de física médica. 8(2):315-321. http://hdl.handle.net/10251/79285S3153218
Choice of the initial antiretroviral treatment for HIV-positive individuals in the era of integrase inhibitors
BACKGROUND: We aimed to describe the most frequently prescribed initial antiretroviral therapy (ART) regimens in recent years in HIV-positive persons in the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) and to investigate factors associated with the choice of each regimen. METHODS: We analyzed initial ART regimens prescribed in adults participating in CoRIS from 2014 to 2017. Only regimens prescribed in >5% of patients were considered. We used multivariable multinomial regression to estimate Relative Risk Ratios (RRRs) for the association between sociodemographic and clinical characteristics and the choice of the initial regimen. RESULTS: Among 2874 participants, abacavir(ABC)/lamivudine(3TC)/dolutegavir(DTG) was the most frequently prescribed regimen (32.1%), followed by tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)/elvitegravir(EVG)/cobicistat(COBI) (14.9%), TDF/FTC/rilpivirine (RPV) (14.0%), tenofovir alafenamide (TAF)/FTC/EVG/COBI (13.7%), TDF/FTC+DTG (10.0%), TDF/FTC+darunavir/ritonavir or darunavir/cobicistat (bDRV) (9.8%) and TDF/FTC+raltegravir (RAL) (5.6%). Compared with ABC/3TC/DTG, starting TDF/FTC/RPV was less likely in patients with CD4100.000 copies/mL. TDF/FTC+DTG was more frequent in those with CD4100.000 copies/mL. TDF/FTC+RAL and TDF/FTC+bDRV were also more frequent among patients with CD4<200 cells//muL and with transmission categories other than men who have sex with men. Compared with ABC/3TC/DTG, the prescription of other initial ART regimens decreased from 2014-2015 to 2016-2017 with the exception of TDF/FTC+DTG. Differences in the choice of the initial ART regimen were observed by hospitals' location. CONCLUSIONS: The choice of initial ART regimens is consistent with Spanish guidelines' recommendations, but is also clearly influenced by physician's perception based on patient's clinical and sociodemographic variables and by the prescribing hospital location
The new neutron multiplicity filter NEDA and its first physics campaign with AGATA
A new neutron multiplicity filter NEDA, after a decade of design, R&D and construction, was employed in its first physics campaign with the AGATA spectrometer. Properties and performance of the array are discussed
Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics
The burrowing behavior of the nematode Caenorhabditis elegans: a new assay for the study of neuromuscular disorders 1
The nematode Caenorhabditis elegans has been a powerful model system for the study of key muscle genes relevant to human neuromuscular function and disorders. The behavioral robustness of C. elegans, however, has hindered its use in the study of certain neuromuscular disorders because many worm models of human disease show only subtle phenotypes while crawling. By contrast, in their natural habitat, C. elegans likely spends much of the time burrowing through the soil matrix. We developed a burrowing assay to challenge motor output by placing worms in agar-filled pipettes of increasing densities. We find that burrowing involves distinct kinematics and turning strategies from crawling that vary with the properties of the substrate. We show that mutants mimicking Duchenne muscular dystrophy by lacking a functional ortholog of the dystrophin protein, DYS-1, crawl normally but are severely impaired in burrowing. Muscular degeneration in the dys-1 mutant is hastened and exacerbated by burrowing, while wild type shows no such damage. To test whether neuromuscular integrity might be compensated genetically in the dys-1 mutant, we performed a genetic screen and isolated several suppressor mutants with proficient burrowing in a dys-1 mutant background. Further study of burrowing in C. elegans will enhance the study of diseases affecting neuromuscular integrity, and will provide insights into the natural behavior of this and other nematodes
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