Abstract Objective We wished to develop a highly selective positron emission tomography (PET) imaging agent targeting PHF-tau in human Alzheimer's disease (AD) brains. Methods To screen potential tau ...binders, human AD brain sections were used as a source of native paired helical filament (PHF)-tau and Aβ rather than synthetic tau aggregates or Aβ fibrils generated in vitro to measure the affinity and selectivity of 18 FT807 to tau and Aβ. Brain uptake and biodistribution of 18 FT807 in mice were also tested. Results In vitro autoradiography results show that 18 FT807 exhibits strong binding to PHF-tau-positive human brain sections. A dissociation constant ( Kd ) of 18 FT807 (14.6 nM) was measured using brain sections from the frontal lobe of AD patients. A comparison of autoradiography and double immunohistochemical staining of PHF-tau and Aβ on adjacent sections demonstrated that 18 FT807 binding colocalized with immunoreactive PHF-tau pathology, but did not highlight Aβ plaques. In vivo studies in mice demonstrated that 18 FT807 was able to cross the blood–brain barrier and washed out quickly. Conclusions 18 FT807 demonstrates high affinity and selectivity to PHF-tau as well as favorable in vivo properties, making this a promising candidate as an imaging agent for AD.
This study examines associations between neighborhood environment attributes and health related quality of life (HRQOL) and self-rated health (SRH) among older adults (60 years and over) in Bogotá, ...Colombia. Perceived and objective neighborhood environmental characteristics were assessed in a cross sectional multilevel design with 1966 older adults within 50 neighborhoods. Outcome variables included HRQOL (physical and mental dimensions) and SRH measured with the Spanish version of the Short Form 8 (SF-8). Independent variables included perceived and objective neighborhood characteristics as well as self-reported levels of walking. Hierarchical linear and logistic regression models were used for the analysis. Among perceived neighborhood characteristics, safety from traffic was positively associated with both HRQOL dimensions and SRH. Having safe parks was positively associated with the mental dimension of HRQOL and with SRH. Street noise was negatively associated with both HRQOL dimensions. Regarding objective neighborhood characteristics, residing in areas with more than eight percent of land covered by public parks was positively associated with SRH. Objective and perceived neighborhood characteristics could provide insight into potential interventions among older adults from rapidly urbanizing settings in Latin America.
Patients suffering from Parkinson's disease (PD) present a reduction in facial movements called hypomimia. In this work, we propose to use machine learning facial expression analysis from face images ...based on action unit domains to improve PD detection. We propose different domain adaptation techniques to exploit the latest advances in automatic face analysis and face action unit detection.
Three different approaches are explored to model facial expressions of PD patients: (i) face analysis using single frame images and also using sequences of images, (ii) transfer learning from face analysis to action units recognition, and (iii) triplet-loss functions to improve the automatic classification between patients and healthy subjects.
Real face images from PD patients show that it is possible to properly model elicited facial expressions using image sequences (neutral, onset-transition, apex, offset-transition, and neutral) with accuracy improvements of up to 5.5% (from 72.9% to 78.4%) with respect to single-image PD detection. We also show that our proposed action unit domain adaptation provides improvements of up to 8.9% (from 78.4% to 87.3%) with respect to face analysis. Finally, we also show that triplet-loss functions provide improvements of up to 3.6% (from 78.8% to 82.4%) with respect to action unit domain adaptation applied upon models created from scratch. The code of the experiments is available at https://github.com/luisf-gomez/Explorer-FE-AU-in-PD.
Domain adaptation via transfer learning methods seem to be a promising strategy to model hypomimia in PD patients. Considering the good results and also the fact that only up to five images per participant are considered in each sequence, we believe that this work is a step forward in the development of inexpensive computational systems suitable to model and quantify problems of PD patients in their facial expressions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background There is increasing evidence that the built environment has an influence on physical activity; however, little is known about this relationship in developing countries. Purpose This study ...examined the associations between attributes of the built environment and walking patterns among the elderly. Methods A multilevel cross-sectional study was conducted in 2007. Fifty neighborhoods were selected and 1966 participants aged ≥60 years were surveyed. Objective built environment measures were obtained in a buffer of 500 m using GIS. Environmental perceptions were assessed via questionnaire. Results People who lived in areas with middle park area (4.53%–7.98% of land) were more likely to walk for at least 60 minutes during a usual week (prevalence OR POR=1.42, 95% CI=1.02, 1.98). Those who lived in areas with the highest connectivity index (1.81–1.99) were less likely to report walking for at least 60 minutes (POR=0.64, 95% CI=0.44, 0.93). Participants who reported feeling safe or very safe from traffic were more likely to report walking for at least 60 minutes (POR=1.50, 95% CI=1.11, 2.03). The presence of Ciclovía (recreational program) was marginally associated with having walked at least 150 minutes in a usual week (POR=1.29, 95% CI=0.97, 1.73). Conclusions This study showed that certain built and perceived environment characteristics were associated with walking among older adults living in Bogotá. Further studies should be conducted to better understand the potential influence of the built environment on physical activity among the elderly population in the context of Latin American cities.
We report on the observation of vortices in superfluid 4He droplets produced in the expansion of liquid He. The vortices were traced by introducing Ag atoms, which clustered along the vortex lines, ...into the droplets. The Ag clusters were subsequently surface-deposited and imaged via electron microscopy. The prevalence of elongated track-shaped deposits shows that vortices are present in droplets larger than about 300 nm and that their lifetime exceeds a few milliseconds. We discuss the possible formation mechanisms and the stability of the vortices.
Background
Current treatment of immature necrotic permanent teeth with a periapical lesion is regenerative endodontics, which is based on tissue engineering under the triade of stem cells, scaffolds ...and bioactive molecules.
Objectives
This Umbrella Review was aimed to evaluate the success of scaffold and regenerative materials used for the treatment of these teeth, in terms of apical closure, tooth length increase, widening of root canal walls, tissue vitality and periapical lesion repair.
Methods
An extensive literature research was carried out in the Medline, ISI Web of Science, and Scopus databases for relevant systematic reviews matching the keyword search strategy. Based on inclusion and exclusion criteria, reviewers independently rated the quality of each study to determine their level of evidence. Methodological quality assessment of each article was obtained using A Measurement Tool to Assess Systematic Reviews (AMSTAR)‐2 tool, and risk of bias was assessed with the Risk of Bias in Systematic Reviews (ROBIS) tool.
Results
After removing duplicates, 155 articles were found; from which 133 were excluded for being non‐relevant and 15 other due to exclusion criteria. One more was discarded after methodological quality evaluation, for a total of six articles remaining. The most common scaffold used was the blood clot, others used were poly lactic‐co‐glycolic acid and platelet‐rich fibrin matrix. The most common regeneration material used was Mineral Trioxide Aggregate (MTA), followed by Biodentine. An increase in tooth length and widening of root canal walls were reported in all selected studies with different proportions, as well as periapical lesion repair. ROBIS analysis showed that only one article had low bias, two were classified as unclear bias, while the remaining three had high risk of bias.
Discussion
An exhaustive literature search was carried out applying language filters, high‐quality indexed journals, year of publication, which ensures the best quality articles were included. Blood clot was the most used scaffold as is the most easy to place inside the canal and does not require to extract blood from the patient. The use of MTA and Biodentine as sealing materials has been associated with thickening of canal walls, apical closure and reduced signs and symptoms of apical periodontitis. However, most of the included reviews assessed were case reports and only in a few of them were clinical trials included. There is also a lack of risk of bias analysis in most reviews.
Conclusion
The blood clot is the most common scaffold used for inducing regeneration during the treatment of immature necrotic teeth. Tooth length increase and widening of root canal walls are the most common criteria used in the studies as success indicators. MTA and Biodentine did not show differences in the results analysed. Quality assessment and bias risk evaluation showed that it is necessary to design better studies with rigorous methodology to recommend a trustable and predictable protocol for the treatment of immature necrotic permanent teeth with periapical lesions.
Registration
International Prospective Register of Systematic Reviews (PROSPERO) CRD42021248404.
We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the millimeter emission ...of this disk with the highest angular resolution so far (0 12 × 0 09, or 14 au × 11 au, at 7 mm). Our 7 and 9 mm images show a narrow ring of emission at a radius of ∼25 au tracing the outer edge of the inner gap. This ring presents an asymmetric morphology that could be produced by dynamical interactions between the disk and forming planets. Additionally, the azimuthally averaged radial intensity profiles of the 7 and 9 mm images confirm the presence of the previously reported gap at ∼45 au and reveal a new gap at ∼85 au. We analyzed archival DCO+(3-2) and C18O(2-1) ALMA observations, showing that the CO snowline is located very close to this third outer gap. This suggests that growth and accumulation of large dust grains close to the CO snowline could be the mechanism responsible for this proposed outer gap. Finally, a compact source of emission is detected at 7 mm, 9 mm, and 3 cm toward the center of the disk. Its flux density and spectral index indicate that it is dominated by free-free emission from ionized gas, which could be associated with the photoionization of the inner disk, an independent object, or an ionized jet.
Abstract
We present Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations of the close (0.″3 = 90 au separation) protobinary system SVS 13. We detect two small ...circumstellar disks (radii ∼12 and ∼9 au in dust, and ∼30 au in gas) with masses of ∼0.004–0.009
M
☉
for VLA 4A (the western component) and ∼0.009–0.030
M
☉
for VLA 4B (the eastern component). A circumbinary disk with prominent spiral arms extending ∼500 au and a mass of ∼0.052
M
☉
appears to be in the earliest stages of formation. The dust emission is more compact and with a very high optical depth toward VLA 4B, while toward VLA 4A the dust column density is lower, allowing the detection of stronger molecular transitions. We infer rotational temperatures of ∼140 K, on scales of ∼30 au, across the whole source, and a rich chemistry. Molecular transitions typical of hot corinos are detected toward both protostars, being stronger toward VLA 4A, with several ethylene glycol transitions detected only toward this source. There are clear velocity gradients, which we interpret in terms of infall plus rotation of the circumbinary disk, and pure rotation of the circumstellar disk of VLA 4A. We measured orbital proper motions and determined a total stellar mass of 1
M
☉
. From the molecular kinematics, we infer the geometry and orientation of the system, and stellar masses of ∼0.26
M
☉
for VLA 4A and ∼0.60
M
☉
for VLA 4B.
Like cervical cancer, anal cancer is often caused by a human papillomavirus and has a premalignant stage called high-grade squamous intraepithelial lesion or anal intraepithelial neoplasia. A ...randomized trial showed that treating HSIL led to a 57% reduction in progression to anal cancer as compared with active surveillance.
![[18 F]T807, a novel tau pos...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1552-5260/small "[18 F]T807, a novel tau positron emission tomography imaging agent for Alzheimer's disease")
PDF
