To evaluate the diagnostic performance of three versions of a deep-learning convolutional neural network in terms of object detection and segmentation using a multiclass panoramic radiograph dataset.
...A total of 600 orthopantomographies were randomly selected for this study and manually annotated by a single operator using an image annotation tool (COCO Annotator v.11.0.1) to establish ground truth. The annotation classes included teeth, maxilla, mandible, inferior alveolar nerve, dento- and implant-supported crowns/pontics, endodontic treatment, resin-based restorations, metallic restorations, and implants. The dataset was then divided into training, validation, and testing subsets, which were used to train versions 5, 7, and 8 of You Only Look Once (YOLO) Neural Network. Results were stored, and a posterior performance analysis was carried out by calculating the precision (P), recall (R), F1 Score, Intersection over Union (IoU), and mean average precision (mAP) at 0.5 and 0.5–0.95 thresholds. The confusion matrix and recall precision graphs were also sketched.
YOLOv5s showed an improvement in object detection results with an average R = 0.634, P = 0.781, mAP0.5 = 0.631, and mAP0.5–0.95 = 0.392. YOLOv7m achieved the best object detection results with average R = 0.793, P = 0.779, mAP0.5 = 0.740, and mAP0.5–0.95 = 0,481. For object segmentation, YOLOv8m obtained the best average results (R = 0.589, P = 0.755, mAP0.5 = 0.591, and mAP0.5–0.95 = 0.272).
YOLOv7m was better suited for object detection, while YOLOv8m demonstrated superior performance in object segmentation. The most frequent error in object detection was related to background classification. Conversely, in object segmentation, there is a tendency to misclassify True Positives across different dental treatment categories.
General diagnostic and treatment decisions based on panoramic radiographs can be enhanced using new artificial intelligence-based tools. Nevertheless, the reliability of these neural networks should be subjected to training and validation to ensure their generalizability.
Observations of transiting extrasolar planets are of key importance to our understanding of planets because their mass, radius, and mass density can be determined. The CoRoT space mission allows us ...to achieve a very high photometric accuracy. By combining CoRoT data with high-precision radial velocity measurements, we derive precise planetary radii and masses. We report the discovery of CoRoT-19b, a gas-giant planet transiting an old, inactive F9V-type star with a period of four days. After excluding alternative physical configurations mimicking a planetary transit signal, we determine the radius and mass of the planet by combining CoRoT photometry with high-resolution spectroscopy obtained with the echelle spectrographs SOPHIE, HARPS, FIES, and SANDIFORD. To improve the precision of its ephemeris and the epoch, we observed additional transits with the TRAPPIST and Euler telescopes. Using HARPS spectra obtained during the transit, we then determine the projected angle between the spin of the star and the orbit of the planet. We find that the host star of CoRoT-19b is an inactive F9V-type star close to the end of its main-sequence life. The host star has a mass M*=1.21+/-0.05 Msun and radius R*=1.65+/-0.04 Rsun. The planet has a mass of Mp=1.11+/-0.06 Mjup and radius of Rp=1.29+/-0.03 Rjup. The resulting bulk density is only rho=0.71+/-0.06 gcm-3, which is much lower than that for Jupiter. The exoplanet CoRoT-19b is an example of a giant planet of almost the same mass as Jupiter but a 30% larger radius.
A high performance liquid chromatographic method with fluorimetric detection has been developed for the quantitation of the angiotensin II receptor antagonist (ARA II) 4-((2-
...n-propyl-4-methyl-6-(1-methylbenzimidazol-2-yl)-benzimidazol-1-yl)methyl)biphenyl-2-carboxylic acid (telmisartan) in urine, using a Novapak C18 column 3.9×150 mm, 4 μm. The mobile phase consisted of a mixture acetonitrile–phosphate buffer (pH 6.0, 5 mM) (45:55, v/v) pumped at a flow rate of 0.5 ml min
−1. Effluent was monitored at excitation and emission wavelengths of 305 and 365 nm, respectively. Separation was carried out at room temperature. Chromatographic variables were optimised by means of experimental design. A clean-up step was used for urine samples consisting of a solid-phase extraction procedure with C8 cartridges and methanol as eluent. This method proved to be accurate (RE from −12 to 6%), precise (intra- and inter-day coefficients of variation (CV) were lower than 8%) and sensitive enough (limit of quantitation (LOQ), ca. 1 μg l
−1) to be applied to the determination of the active drug in urine samples obtained from hypertensive patients. Concentration levels of telmisartan at different time intervals (from 0 up to 36 h after oral intake) were monitorised.
β-Aminobutyric acid is a non-proteinogenic amino acid that is known to protect plants against various pathogens. Its structure is midway between α-aminobutyric acid and γ-aminobutyric acid. The ...structural differences in the position of the amino group in the conformational stabilization of β-aminobutyric acid have been studied by laser ablation Fourier transform microwave spectroscopy. Five conformers have been detected, and their rotational and quadrupole coupling constants of the 14N nucleus determined. Three of the conformers, including the most stable structure, are stabilized by a non-bifurcated N-HOdouble bond, length as m-dashC intramolecular hydrogen bond. The other two conformers possess a NH-O intramolecular interaction. In this work we highlight that β-aminobutyric acid shows the conformational peculiarities of α-aminobutyric acid and γ-aminobutyric acid completing the rotational spectroscopic study of the x-aminobutyric acid series.
Surgery remains to be the main therapeutic approach for retroperitoneal sarcomas (RPS) although evidence supports that complementary radiotherapy increases local-control and survival. We present a ...multidisciplinary management and experience of a tertiary cancer center in the treatment of RPS and analyze current evidence of radiotherapy efficacy.
We retrospectively reviewed 19 patients with primary or relapsed RPS treated between November 2009 and October 2018. Multidisciplinary approach comprised complete resection in 15 patients (79%) achieving resection R0 in 11 patients (58%), R1 in 4 patients (21%) and R2 in 2 patients (10%). Seven patients (37%) underwent a preoperative radiation (PRORT), 10 patients (53%), post-operative radiation (PORT) and 2 patients (10%), received radiotherapy exclusively. Ten patients (53%) received adjuvant chemotherapy.
With a median follow-up of 24 months (2–114 months), actuarial rates of loco-regional relapse free survival (LRFS) at 1, 2 and 3 years were 77%, 77% and 67%, respectively. Actuarial rates of distant-metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) at 1, 2 and 3 years were 100%, 100% and 80% for DMFS; 94%, 77% and 67% for DFS and 100%, 91% and 91% for OS, respectively. Only surgical margins (negative vs. positive) showed significance for 3y-LRFS: 100% vs. 34.3%, p=0.018. Treatment tolerance was acceptable with no acute or late toxicity higher than grade 2.
Complementary radiotherapy appears to be useful and well tolerated for the multidisciplinary management of RPS. Presence of positive surgical margins seems to be the most relevant prognostic factor through the follow-up.
Context. The CoRoT satellite has recently discovered a hot Jupiter that transits across the disc of a F9 main-sequence star called CoRoT-6 with a period of 8.886 days. Aims. We model the photospheric ...activity of the star and use the maps of the active regions to study stellar differential rotation and the star-planet interaction. Methods. We apply a maximum entropy spot model to fit the optical modulation as observed by CoRoT during a uninterrupted interval of ~140 days. Photospheric active regions are assumed to consist of spots and faculae in a fixed proportion with solar-like contrasts. Results. Individual active regions have lifetimes up to 30−40 days. Most of them form and decay within five active longitudes whose different migration rates are attributed to the stellar differential rotation for which a lower limit of ΔΩ/Ω = 0.12 ± 0.02 is obtained. Several active regions show a maximum of activity at a longitude lagging the subplanetary point by ~200° with the probability of a chance occurrence being smaller than 1 percent. Conclusions. Our spot modelling indicates that the photospheric activity of CoRoT-6 could be partially modulated by some kind of star-planet magnetic interaction, while an interaction related to tides is highly unlikely because of the weakness of the tidal force.
Abstract In 1996, the prevalence of multiple sclerosis (MS) for the metropolitan area of Buenos Aires using the capture-recapture method was estimated to be between 14 to 19.8 cases per 100,000 ...inhabitants. The aim of this study was to update the prevalence to 2014 following the same methodology. Methods Gran Buenos Aires is the denomination that refers to the megalopolis comprised by the autonomous city of Buenos Aires and the surrounding conurbation of the province of Buenos Aires. The study was carried out taking December 2014 as the prevalence month. We used the capture-recapture method to estimate the prevalence of MS cross-matching registries from 6 MS Centers from the metropolitan area of Buenos Aires. Log-linear model Poisson regression was used to estimate the number of affected MS patients not detected by any of the 6 sources considered. Results 1035 registries were obtained from the 6 lists from 910 different patients detected. The population of the area based on 2010 census was 12 806 866, the number of MS cases estimated amongst source interactions were 4901. The estimated prevalence was 38.2 per 100,000 inhabitants (95% CI 36.1 to 41.2). Conclusion The study is an update almost 20 years after the first one in the area showing a significant increase in the previous reported prevalence. Our findings are in line with previous studies performed in other regions of the world.
Context.
Numerous complex organic molecules have been detected in the universe and among them are amides, which are considered as prime models for species containing a peptide linkage. In its ...backbone, acrylamide (CH
2
CHC(O)NH
2
) bears not only the peptide bond, but also the vinyl functional group that is a common structural feature in many interstellar compounds. This makes acrylamide an interesting candidate for searches in the interstellar medium. In addition, a tentative detection of the related molecule propionamide (C
2
H
5
C(O)NH
2
) has been recently claimed toward Sgr B2(N).
Aims.
The aim of this work is to extend the knowledge of the laboratory rotational spectrum of acrylamide to higher frequencies, which would make it possible to conduct a rigorous search for interstellar signatures of this amide using millimeter wave astronomy.
Methods.
We measured and analyzed the rotational spectrum of acrylamide between 75 and 480 GHz. We searched for emission of acrylamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimeter/submillimeter Array toward Sgr B2(N). We also searched for propionamide in the same source. The astronomical spectra were analyzed under the assumption of local thermodynamic equilibrium.
Results.
We report accurate laboratory measurements and analyses of thousands of rotational transitions in the ground state and two excited vibrational states of the most stable
syn
form of acrylamide. In addition, we report an extensive set of rotational transitions for the less stable
skew
conformer. Tunneling through a low energy barrier between two symmetrically equivalent configurations has been revealed for this higher-energy species. Neither acrylamide nor propionamide were detected toward the two main hot molecular cores of Sgr B2(N). We did not detect propionamide either toward a position located to the east of the main hot core, thereby undermining the recent claim of its interstellar detection toward this position. We find that acrylamide and propionamide are at least 26 and 14 times less abundant, respectively, than acetamide toward the main hot core Sgr B2(N1S), and at least 6 and 3 times less abundant, respectively, than acetamide toward the secondary hot core Sgr B2(N2).
Conclusions.
A comparison with results of astrochemical kinetics model for related species suggests that acrylamide may be a few hundred times less abundant than acetamide, corresponding to a value that is at least an order of magnitude lower than the observational upper limits. Propionamide may be as little as only a factor of two less abundant than the upper limit derived toward Sgr B2(N1S). Lastly, the spectroscopic data presented in this work will aid future searches of acrylamide in space.
The purpose of this study was to evaluate the biomechanical degradation of two nanofilled restorative materials (a resin-modified glass ionomer, Ketac N100 and a composite, Filtek Z350), compared ...with conventional materials (Vitremer and TPH Spectrum). Twenty specimens obtained from each material were divided into two storage groups (n=10): relative humidity (control) and Streptococcus mutans biofilm (biodegradation). After 7 days of storage, roughness values (Ra) and micrographs by scanning electron microscopy (SEM) were obtained. In a second experimental phase, the specimens previously subjected to biodegradation were fixed to the tooth-brushing device and abraded via toothbrushes, using dentifrice slurry (mechanical degradation). Next, these specimens were washed, dried, and reassessed by roughness and SEM. The data were submitted to repeated measures three-way analysis of variance (ANOVA) and Tukey tests (p<0.05). There was statistically significant interaction among factors: material, storage (humidity/biofilm), and abrasion (before/after). After biodegradation (S mutans biofilm storage), Ketac N100 presented the highest Ra values. Concerning bio plus mechanical challenge, TPH Spectrum, Ketac N100, and Vitremer presented the undesirable roughening of their surfaces, while the nano composite Filtek Z350 exhibited the best resistance to cumulative challenges proposed. The degraded aspect after biodegradation and the exposure of fillers after mechanical degradation were visualized in micrographs. This study demonstrated that the nanotechnology incorporated in restorative materials, as in composite resin and resin-modified glass ionomer, was important for the superior resistance to biomechanical degradation.
PDF
