2,105 research outputs found
RANSAC-NN: Unsupervised Image Outlier Detection using RANSAC
Image outlier detection (OD) is crucial for ensuring the quality and accuracy
of image datasets used in computer vision tasks. The majority of OD algorithms,
however, have not been targeted toward image data. Consequently, the results of
applying such algorithms to images are often suboptimal. In this work, we
propose RANSAC-NN, a novel unsupervised OD algorithm specifically designed for
images. By comparing images in a RANSAC-based approach, our algorithm
automatically predicts the outlier score of each image without additional
training or label information. We evaluate RANSAC-NN against state-of-the-art
OD algorithms on 15 diverse datasets. Without any hyperparameter tuning,
RANSAC-NN consistently performs favorably in contrast to other algorithms in
almost every dataset category. Furthermore, we provide a detailed analysis to
understand each RANSAC-NN component, and we demonstrate its potential
applications in image mislabeled detection. Code for RANSAC-NN is provided at
https://github.com/mxtsai/ransac-nnComment: 19 pages, 18 figure
Use of an open-source CAD software program and additive manufacturing technology to design and fabricate a definitive cast for retrofitting a crown to an existing removable partial denture
This technical report describes a digital process for designing and fabricating a stackable definitive cast and die system to facilitate the fabrication of a new surveyed crown to retrofit to a removable partial denture (RPD). By using an open-source computer-aided design (CAD) software program, this technique provides an economical option for dental clinicians and laboratory technicians to use intraoral scans and design a stackable definitive cast and die system with minimal financial investment in the CAD software. In addition, this technique provides the advantage of a conventional indirect technique in that it can create a definitive cast with an RPD clasp assembly ready for the dental technician to properly contour the new surveyed crown, but without the need for the patient to be without the RPD during the process
The Clumpy Structure Of Five Star-bursting Dwarf Galaxies In The MaNGA Survey
The star-forming clumps in star-bursting dwarf galaxies provide valuable
insights into the understanding of the evolution of dwarf galaxies. In this
paper, we focus on five star-bursting dwarf galaxies featuring off-centered
clumps in the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA)
survey. Using the stellar population synthesis software FADO, we obtain the
spatially-resolved distribution of the star formation history, which allows us
to construct the -band images of the five galaxies at different ages. These
images can help us to probe the evolution of the morphological structures of
these galaxies. While images of stellar population older than 1 Gyr are
typically smooth, images of stellar population younger than 1 Gyr reveal
significant clumps, including multiple clumps which appear at different
locations and even different ages. To study the evolutionary connections of
these five galaxies to other dwarf galaxies before their star-forming clumps
appear, we construct the images of the stellar populations older than three age
nodes, and define them to be the images of the "host" galaxies. We find that
the properties such as the central surface brightness and the effective radii
of the hosts of the five galaxies are in between those of dwarf ellipticals
(dEs) and dwarf irregulars (dIrrs), with two clearly more similar to dEs and
one more similar to dIrrs. Among the five galaxies, 8257-3704 is particularly
interesting, as it shows a previous starburst event that is not quite visible
from its image, but only visible from images of the stellar population at
a few hundred million years. The star-forming clump associated with this event
may have appeared at around 600 Myr and disappeared at around 40 Myr.Comment: 21 pages, 16 figures, accepted for publication in RA
Mammalian target of rapamycin inhibitor and transarterial embolization of tuberous sclerosis complex-associated renal angiomyolipoma: A case series
Coherent narrow-band light source for miniature endoscopes.
In this work, we report the successful implementation of a coherent narrow-band light source for miniature endoscopy applications. An RGB laser module that provides much higher luminosity than traditional incoherent white light sources is used for illumination, taking advantages of the laser light's high spatial coherence for efficient light coupling. Notably, the narrow spectral band of the laser light sources also enables spectrally resolved imaging, to distinguish certain biological tissues or components. A monochrome CMOS camera is employed to synchronize with the time lapsed RGB laser module illumination for color image acquisition and reconstruction, which provides better spatial resolution than a color CMOS camera of comparable pixel number, in addition to spectral resolving
Using Capacitance Sensor to Extract Characteristic Signals of Dozing from Skin Surface
Skin is the largest organ of the human body and a physiological structure that is directly exposed to the environment. From a theoretical perspective, numerous physiological and psychological signals use the skin as a medium for input and output with the outside world. Therefore, the skin is considered an optimal signal interception point when developing noninvasive, direct, and rapid signal exploration devices. To date, skin signal interceptions are predominantly performed by measuring skin impedance. However, this method is prone to interference such as sweat secretion, salt accumulation on the skin, and muscle contractions, which may result in a substantial amount of interference and erroneous results. The present study proposes novel and effective methods for skin signal interception, such as using a nested probe as a sensor to measure capacitance to be further processed as physiological and psychological signals. The experimental results indicate that the capacitance curve for the transition between wakefulness and dozing exhibits significant changes. This change in the curve can be analyzed by computer programs to clearly and rapidly determine whether the subject has entered the initial phases of sleep
Usability Assessment of a Cable-Driven Exoskeletal Robot for Hand Rehabilitation
Study design: Case series.Background: Robot-assisted rehabilitation mediated by exoskeletal devices is a popular topic of research. The biggest difficulty in the development of rehabilitation robots is the consideration of the clinical needs. This study investigated the usability of a novel cable-driven exoskeletal robot specifically designed for hand rehabilitation.Methods: The study consists of three steps, including prototype development, spasticity observation, and usability evaluation. First, we developed the prototype robot DexoHand to manipulate the patient's fingers based on the clinical needs and the cable-driven concept established in our previous work. Second, we applied DexoHand to patients with different levels of spasticity. Finally, we obtained the system usability scale (SUS) and assessed its usability.Results: Two healthy subjects were recruited in the pre-test, and 18 patients with stroke and four healthy subjects were recruited in the formal test for usability. The total SUS score obtained from the patients and healthy subjects was 94.77 Β± 2.98 (n = 22), indicating an excellent level of usability. The satisfaction score was 4.74 Β± 0.29 (n = 22), revealing high satisfaction with DexoHand. The tension profile measured by the cables showed the instantaneous force used to manipulate fingers among different muscle tone groups.Conclusions:DexoHand meets the clinical needs with excellent usability, satisfaction, and reliable tension force monitoring, yielding a feasible platform for robot-assisted hand rehabilitation
Adipose-Derived Mesenchymal Stem Cell Protects Kidneys against Ischemia-Reperfusion Injury through Suppressing Oxidative Stress and Inflammatory Reaction
<p>Abstract</p> <p>Background</p> <p>Reactive oxygen species are important mediators exerting toxic effects on various organs during ischemia-reperfusion (IR) injury. We hypothesized that adipose-derived mesenchymal stem cells (ADMSCs) protect the kidney against oxidative stress and inflammatory stimuli in rat during renal IR injury.</p> <p>Methods</p> <p>Adult male Sprague-Dawley (SD) rats (n = 24) were equally randomized into group 1 (sham control), group 2 (IR plus culture medium only), and group 3 (IR plus immediate intra-renal administration of 1.0 Γ 10<sup>6 </sup>autologous ADMSCs, followed by intravenous ADMSCs at 6 h and 24 h after IR). The duration of ischemia was 1 h, followed by 72 hours of reperfusion before the animals were sacrificed.</p> <p>Results</p> <p>Serum creatinine and blood urea nitrogen levels and the degree of histological abnormalities were markedly lower in group 3 than in group 2 (all p < 0.03). The mRNA expressions of inflammatory, oxidative stress, and apoptotic biomarkers were lower, whereas the anti-inflammatory, anti-oxidative, and anti-apoptotic biomarkers were higher in group 3 than in group 2 (all p < 0.03). Immunofluorescent staining showed a higher number of CD31+, von Willebrand Factor+, and heme oxygenase (HO)-1+ cells in group 3 than in group 2 (all p < 0.05). Western blot showed notably higher NAD(P)H quinone oxidoreductase 1 and HO-1 activities, two indicators of anti-oxidative capacity, in group 3 than those in group 2 (all p < 0.04). Immunohistochemical staining showed higher glutathione peroxidase and glutathione reductase activities in group 3 than in group 2 (all p < 0.02)</p> <p>Conclusion</p> <p>ADMSC therapy minimized kidney damage after IR injury through suppressing oxidative stress and inflammatory response.</p
Preoperative Proteinuria Is Associated with Long-Term Progression to Chronic Dialysis and Mortality after Coronary Artery Bypass Grafting Surgery
AIMS: Preoperative proteinuria is associated with post-operative acute kidney injury (AKI), but whether it is also associated with increased long-term mortality and end-stage renal disease (ESRD) is unknown. METHODS AND RESULTS: We studied 925 consecutive patients undergoing CABG. Demographic and clinical data were collected prospectively, and patients were followed for a median of 4.71 years after surgery. Proteinuria, according to dipstick tests, was defined as mild (trace to 1+) or heavy (2+ to 4+) according to the results of the dipstick test. A total of 276 (29.8%) patients had mild proteinuria before surgery and 119 (12.9%) patients had heavy proteinuria. During the follow-up, the Cox proportional hazards model demonstrated that heavy proteinuria (hazard ratio [HR], 27.17) was an independent predictor of long-term ESRD. There was a progressive increased risk for mild proteinuria ([HR], 1.88) and heavy proteinuria ([HR], 2.28) to predict all-cause mortality compared to no proteinuria. Mild ([HR], 2.57) and heavy proteinuria ([HR], 2.70) exhibited a stepwise increased ratio compared to patients without proteinuria for long-term composite catastrophic outcomes (mortality and ESRD), which were independent of the baseline GFR and postoperative acute kidney injury (AKI). CONCLUSION: Our study demonstrated that proteinuria is a powerful independent risk factor of long-term all-cause mortality and ESRD after CABG in addition to preoperative GFR and postoperative AKI. Our study demonstrated that proteinuria should be integrated into clinical risk prediction models for long-term outcomes after CABG. These results provide a high priority for future renal protective strategies and methods for post-operative CABG patients
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