Measurement of the mechanical properties of soccer balls using digital image correlation method

There are some features for an approved soccer ball by Fédération Internationale de Football Association (FIFA), such as properties of the material, mass, pressure, stitches, etc. Many of these features up to now have been studied; nevertheless, the mechanical properties of the soccer balls to date have not been well reported. The chief purposes of the current research, hence, were to calculate the mechanical properties of the soccer balls, i.e., linear elastic, nonlinear hyperelastic, and viscoelastic, at two different sizes, including 4 and 5 which are using for football and futsal, respectively. To do this, compressive and stress-relaxation loading were applied to 38 approved soccer balls to quantify the stress–strain as well as reduced relaxation function of the balls. The strain/displacement of the balls was also measured via a high-speed camera using Digital Image Correlation (DIC) technique. The results revealed the mean elastic modulus of 66 and 67 kPa for the football and futsal balls, respectively. In addition, the maximum stresses of the football and futsal balls were 16 and 13 kPa, respectively. The nonlinear mechanical response of the soccer balls were analyzed using hyperelastic material models, i.e., Mooney-Rivlin and Ogden. A Finite Element (FE) model was also developed to verify the hyperelastic data compared to the experimental ones and, remarkably, the numerical data were in consistence with the experimental data. Finally, Prony- series was employed to quantify the viscoelastic properties of the balls. During the game, a soccer ball can reach to a speed of 210 km/h that can damage the human eye; however, the injury detail still has not been studied.     

Effect of hydroxychloroquine on treatment and recurrence of acute brucellosis: a single-blind,randomized clinical trial

Brucellosis is associated with a high recurrence rate and requires more than one course of standard treatment; therefore, more research is required to find more effective treatments that lead to prompt recovery, and reduce the relapse of disease. This single-blind, randomized study was designed to evaluate the effect of the standard treatment for brucellosis in combination with hydroxychloroquine.A total of 177 patients with acute brucellosis were randomly assigned to one of two treatment groups: doxycycline-streptomycin (DS) and doxycycline-streptomycin-hydroxychloroquine (DSH). Clinical symptoms and signs, serological tests, and side effects of therapy were compared between the two groups during the treatment course and at three and six months after the end of drug therapy. Of the 177 patients, with a mean age of 40.5?±?16.9 years, 66.1% were males. The mean duration of clinical signs prior to admission was 43.4?±?41.1 days. Appropriate clinical responses, relapse, treatment failure, and adverse drug reactions were seen in 98.9%, 1.2%, 0.0%, and 12.6% of patients, respectively, in the DSH group vs. 86.7%, 11.6%, 2.3%, and 19.8% of patients, respectively, in the DS group. There were significant differences in clinical response and relapse rates between the two groups. The addition of hydroxychloroquine to a doxycycline-streptomycin regimen appears to increase the efficacy of treatment, accelerate improvement of clinical symptoms, and significantly reduce the rate of relapse of brucellosis.     

A new method for the solution of hybrid analog digital beamforming problems

By going to millimeter wave (mmWave) we can use large scale MIMO due to short mmWave wavelength to overcome path loss by using beamforming to focus power of signal to the receiver. System structure of mmWave band is different with conventional MIMO because of large scale MIMO which is leading to use many RF-chains. For this reason Hybrid structure have been proposed for large Scale MIMO. By going to Hybrid structure a new issue has been created with phase shifter constraint. In this paper we propose a novel solution to make a hybrid precoding and combing to reach high spectral efficiency. Our problem includes a maximizing Frobenius norm of multiplying five complex matrices. As constraints, all elements of some matrices must have unit norm, and also the multiplication of some matrices must have a specific Frobenius norm. A novel solution is proposed for the problem, which is gained in two steps. At the first step, we propose a new decomposition usable for kind of complex matrices which could lead to reduce the dimension of the objective function, and eliminating constraints completely and in the second step, we propose an iterated algorithm for the resulting problem. By proposing another novel technique, we show that in each iteration, the optimal problem is equivalent to a quadratic optimal problem with limitations on the vector norm, and as a result, an optimal problem is obtained quickly. Moreover, some other real examples are included to demonstrate the usefulness and effectiveness of the proposed algorithm.     

Minocycline attenuates testicular damages in a rat model of ischaemia/reperfusion (I/R) injury

Testicular torsion is a serious urological disease leading to testicular damage. This study aimed to assess the effect of minocycline on testicular ischaemia/reperfusion (I/R) injury caused by testicular torsion/detorsion. Male adult Wistar rats (n = 32) were assigned into four groups of sham, I/R, I/R + minocycline and minocycline. I/R injury was induced by two sets of surgical operations, including the rotation of the left testis (720°, counterclockwise), followed by detorsion after 4 hr. The administration of minocycline was carried out 30 min before detorsion and then continued for 8 weeks. At the end of the 8th week, rats were killed and sampling was done. Johnson's score, the height of seminiferous tubule epithelium, the mean seminiferous tubule diameter, as well as biochemical parameters, SOD, GPx and CAT, were significantly enhanced in the I/R + minocycline group compared with the I/R group. The administration of minocycline led to a marked decrease in expression levels of Caspase-3, Bax, IL-1β and TNF-α genes, and a remarkable increase in expression levels of Bcl-2, 3β-HSD and 17β-HSD3 genes compared with the I/R group. Administration of minocycline could also reduce the rate of germ cell apoptosis (TUNEL staining). Hence, minocycline was useful in the management of testicular torsion/detorsion.     

Preparation and Optimization of Chitosan/pDNA Nanoparticles Using Electrospray

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Chitosan (CS), as a natural polymer, has received a great deal of attention as a carrier for delivery of...     

Population genetics of 30 insertion/deletion polymorphisms in the Kuwaiti population

International Journal of Legal Medicine - This study evaluates the forensic utility of the 30 insertion and deletion (indel) markers contained in the Qiagen Investigator® DIPplex kit in the...     

Gender differences in the spatial–temporal variability between walking and running

Sport Sciences for Health - The pattern of gender differences in gait variability has not yet been well examined. The aim of the present study was therefore to investigate gender differences in the...     

Efficacy and safety of Romosozumab in treatment for low bone mineral density: a systematic review and meta-analysis

Clinical Rheumatology - Osteoporosis is a chronic skeletal disease with an increasing prevalence. Romosozumab, as a monoclonal anti-sclerostin antibody with a dual function, has been produced. In...