Deep Learning networks with p-norm loss layers for spatial resolution enhancement of 3D medical images

Thurnhofer-Hemsi K., López-Rubio E., Roé-Vellvé N., Molina-Cabello M.A. (2019) Deep Learning Networks with p-norm Loss Layers for Spatial Resolution Enhancement of 3D Medical Images. In: Ferrández Vicente J., Álvarez-Sánchez J., de la Paz López F., Toledo Moreo J., Adeli H. (eds) From Bioinspired Systems and Biomedical Applications to Machine Learning. IWINAC 2019. Lecture Notes in Computer Science, vol 11487. Springer, ChamNowadays, obtaining high-quality magnetic resonance (MR) images is a complex problem due to several acquisition factors, but is crucial in order to perform good diagnostics. The enhancement of the resolution is a typical procedure applied after the image generation. State-of-the-art works gather a large variety of methods for super-resolution (SR), among which deep learning has become very popular during the last years. Most of the SR deep-learning methods are based on the min- imization of the residuals by the use of Euclidean loss layers. In this paper, we propose an SR model based on the use of a p-norm loss layer to improve the learning process and obtain a better high-resolution (HR) image. This method was implemented using a three-dimensional convolutional neural network (CNN), and tested for several norms in order to determine the most robust t. The proposed methodology was trained and tested with sets of MR structural T1-weighted images and showed better outcomes quantitatively, in terms of Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM), and the restored and the calculated residual images showed better CNN outputs.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Should distal radioulnar joint be fixed following volar plate fixation of distal radius fracture with unstable distal radioulnar joint?

AbstractBackgroundDistal radioulnar joint (DRUJ) instability often accompanies distal radial fractures. The goal of this study was to investigate whether DRUJ should be fixed to prevent recurrent DRUJ instability in distal radius fracture patients with unstable DRUJ following open reduction and volar plate fixation of the radius.MethodsA retrospective chart review was performed on forty-nine consecutive patients presenting distal radius fracture who were diagnosed with distal radioulnar instability after radius fixation with volar plate. Group one consisted of 24 patients whose DRUJs were fixed in neutral for 6weeks with 1∼2 Kirschner wires (8 cases combined with casting), whereas group two consisted of 25 patients without DRUJ fixation. All patients had radiographic evaluation of their wrist and DRUJ for stabilities and underwent functional evaluation using modified Gartland and Werley demerit scoring system (GW score).ResultsAll patients were followed-up for an average of 15months (12–24months) after surgery. No significant difference was noted between the two groups with respect to gender, age, fracture types and damage types (no noteworthy medical comorbidities in either group). At the latest follow-up, patients in both groups had comparable grip strength, wrist motion, and visual analogue scale (VAS) and GW scores. Only one patient (2.4%) demonstrated DRUJ chronic instability, but did not require any additional surgery.ConclusionThe results suggest that in patients with distal radius fractures, fixation of unstable DRUJs in neutral for 6weeks does not have an advantage over non-fixation.Level of evidenceIII

L-Monomethyl-arginine decreases apoptosis of chondrocytes by altering Bax and Bcl-2 expression in osteoarthritis of rabbit knee

Previous studies found that NG-monomethyl-L-arginine (L-NMMA) treatment inhibits progression of osteoarthritis. Here, we aimed to explore the effects of L-NMMA on chondrocyte apoptosis and Bax and Bcl-2 mRNA expression in rabbits with knee osteoarthritis. Knee osteoarthritis was induced in 24 healthy rabbits by Hulth method, and rabbits were randomly divided into control (n = 12) and experimental (n = 12) groups. Once weekly, knee joints of control rabbits were injected with saline solution, while knees of experimental rabbits were injected with L-NMMA. Knee joint samples were collected after 6 weeks of treatment. Apoptosis of chondrocytes was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and Bax and Bcl-2 mRNA expression by in situ hybridization. The results show that the mean rate of chondrocyte apoptosis in knees of the experimental rabbits was significantly lower than that of the control rabbits (P<0.05). Additionally, Bax expression decreased and Bcl-2 expression increased in the experimental group (P<0.05). In brief, LNMMA can inhibit apoptosis of joint chondrocytes through changes in the expression of apoptosisrelated genes. Thus, this molecule offers the potential for treating osteoarthritis.Key words: NG-Monomethyl-L-arginine, knee osteoarthritis, chondrocyte, apoptosis-related regulatory gene

Realizability of n-port resistive networks with 2n terminals

In this paper, we consider the realizability problem of n-port resistive networks containing 2n terminals. A necessary and sufficient condition for any real symmetric matrix to be realizable as the admittance of an n-port resistive network containing 2n terminals is obtained. The condition is based on the existence of a parameter matrix. We then focus on a three-port resistive network containing six terminals. A necessary and sufficient condition is derived for any real symmetric matrix to be realizable as the admittance of a three-port resistive network containing six terminals and at most five positive elements, whose topological structure is properly restricted. © 2013 IEEE.published_or_final_versio

Dynamical study of the possible molecular state X(3872) with the s-channel one gluon exchange interaction

The recently observed X(3872) resonance, which is difficult to be assigned a conventional $c\bar{c}$ charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the hidden flavor multi-quark system. In this paper, we will study the X(3872) and other similiar hidden flavor molecular states in a quark model by taking into account of the s-channel one gluon exchange interaction