352 research outputs found
A Novel Generator with Auxiliary Branch for Improving GAN Performance
The generator in the generative adversarial network (GAN) learns image
generation in a coarse-to-fine manner in which earlier layers learn the overall
structure of the image and the latter ones refine the details. To propagate the
coarse information well, recent works usually build their generators by
stacking up multiple residual blocks. Although the residual block can produce a
high-quality image as well as be trained stably, it often impedes the
information flow in the network. To alleviate this problem, this brief
introduces a novel generator architecture that produces the image by combining
features obtained through two different branches: the main and auxiliary
branches. The goal of the main branch is to produce the image by passing
through the multiple residual blocks, whereas the auxiliary branch is to convey
the coarse information in the earlier layer to the later one. To combine the
features in the main and auxiliary branches successfully, we also propose a
gated feature fusion module that controls the information flow in those
branches. To prove the superiority of the proposed method, this brief provides
extensive experiments using various standard datasets including CIFAR-10,
CIFAR-100, LSUN, CelebA-HQ, AFHQ, and tiny-ImageNet. Furthermore, we conducted
various ablation studies to demonstrate the generalization ability of the
proposed method. Quantitative evaluations prove that the proposed method
exhibits impressive GAN performance in terms of Inception score (IS) and
Frechet inception distance (FID). For instance, the proposed method boosts the
FID and IS scores on the tiny-ImageNet dataset from 35.13 to 25.00 and 20.23 to
25.57, respectively
Biomechanical Analysis of Biodegradable Cervical Plates Developed for Anterior Cervical Discectomy and Fusion
Study Design In-vitro biomechanical investigation. Purpose To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. Overview of Literature Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. Methods A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4–C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5–C6 segment) and adjacent (C4–C5 segment) levels. Results The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. Conclusions The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period
Effects of a dielectric barrier discharge (DBD) on characteristics of polyaniline nanoparticles synthesized by a solution plasma process with an Ar gas bubble channel
The quality of polyaniline nanoparticles (PANI NPs) synthesized in plasma polymerization depends on the discharge characteristics of a solution plasma process (SPP). In this paper, the low temperature dielectric barrier discharge (DBD) is introduced to minimize the destruction of aniline molecules induced by the direct current (DC) spark discharge. By adopting the new electrode structure coupled with a gas channel, a low temperature DBD is successfully implemented in a SPP, for the first time, thus inducing an effective interaction between the Ar plasma and aniline monomer. We examine the effects of a low temperature DBD on characteristics of polyaniline nanoparticles synthesized by a SPP with an Ar gas bubble channel. As a result, both carbonization of aniline monomer and erosion of the electrode are significantly reduced, which is confirmed by analyses of the synthesized PANI NPs. © 2020 by the authors.1
Association between Workplace Risk Factor Exposure and Sleep Disturbance: Analysis of the 2nd Korean Working Conditions Survey
OBJECTIVES: Sleep is essential for human beings to live and work properly. This study was conducted to investigate the relationship between occupational exposures to workplace risk factors and sleep disturbance in Korean workers. METHODS: The data were drawn from the second Korean Working Conditions Survey (KWCS); a total of 7,112 paid workers were analyzed. The independent variables were occupational exposures such as physical, chemical, biological, and psychosocial risk factor in the workplace, and psychosocial risk factor was divided into five categories (job demand, job control, social support, job insecurity, lack of reward). We estimated the relationship between various occupational exposures and sleep disturbance using multivariate logistic regression analysis. RESULTS: The results showed that people who exposed to physical, chemical, biological, and psychosocial (high job demand, inadequate social support, lack of reward) risk factors were more likely to increase the risk of sleep disturbance. Furthermore, after adjusting for general and occupational characteristics, we found significant positive associations between exposures to physical (odds ratios [OR] 1.47, 95% confidence interval [CI] 1.05-2.07) and psychosocial (high job demand (OR 2.93, 95% CI 2.16-3.98), inadequate social support (OR 1.57, 95% CI 1.14-2.15), lack of reward (OR 1.45, 95% CI 1.08-1.96)) risk factors and sleep disturbance. CONCLUSION: These results suggest that occupational exposures to physical and psychosocial workplace risk factors are significantly related to sleep disturbance
Pharmacokinetics of Amitriptyline Demethylation;A Crossover Study with Single Doses of Amitriptyline and Nortriptyline
A single dose crossover pharmacokinetic study of amitriptyline and nortriptyline
was done to find out the extent of first-pass metabolism to nortriptyline after amitripyline
administration, and the contribution of nortriptyline during amitriptyline therapy. Six healthy
male volunteers took part in this study and were given single doses (50 mg) of amitriptyline
and nortriptyline at more than three-week intervals. Plasma concentrations of the drugs were
measured up to 48 hours. Total area under the plasma concentration-time curve (AUe) of
amitriptyline (744.6±258.4 ng/ml·hl was smaller than that of nortriptyline (l497.3±589.8
ng/ml'h), and the mean terminal half-life of amitriptyline (21.8±3.9 hr) was shorter than
that of nortriptyline (36.8±5.9 h). The total area under the plasma concentration-time curve
of nortriptyline produced by amitriptyline administration was 498.1 ±274.5 ng/ml·h, and the
fraction produced by the first-pass of amitriptyline was 33.7 ± 10.5%.
From this data, it can be estimated that the average nortriptyline concentration could be
about 40% of the total tricyclic antidepressants present in the plasma of patients taking
multiple amitriptyline therapy at steady state. About 34% of nortriptyline is produced by
first- pass effect during gastrointestinal absorption of amitriptyline to systemic circulation resulting
from N-demethylation of amitriptyline in the liver. Then, the rest of the nortriptyline is
formed continuously at a rate proportional to the rate of amitriptyline elimination
Development of a high-density piezoelectric micromachined ultrasonic transducer array based on patterned aluminum nitride thin film
This study presents the fabrication and characterization of a piezoelectric micromachined ultrasonic transducer (pMUT; radius: 40 μm) using a patterned aluminum nitride (AlN) thin film as the active piezoelectric material. A 20 x 20 array of pMUTs using a 1 μm thick AlN thin film was designed and fabricated on a 2 x 2 mm2 footprint for a high fill factor. Based on the electrical impedance and phase of the pMUT array, the electromechanical coefficient was ~1.7% at the average resonant frequency of 2.82 MHz in air. Dynamic displacement of the pMUT surface was characterized by scanning laser Doppler vibrometry. The pressure output while immersed in water was 19.79 kPa when calculated based on the peak displacement at the resonant frequency. The proposed AlN pMUT array has potential applications in biomedical sensing for healthcare, medical imaging, and biometrics. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.1
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