Varicocele treatment: A 2-centers comparison between non microsurgical open correction, laparoscopic approach and retrograde percutaneous sclerotization on 463 cases

Objectives: To determine whether there are differences in sperm parameters improvement after different varicocele correction techniques. To determine the role of age in sperm parameters improvement. Methods: 2 different European centers collected pre- and postoperative sperm parameters of patients undergoing varicocele correction. Among 463 evaluated patients, 367 were included. Patients were divided in procedure-related and age-related groups. Ivanissevich inguinal open surgical procedure (OS), lymphatic-sparing laparoscopic approach (LSL) and retrograde percutaneous transfemoral sclerotization (RPS) were performed. As outcome measurements sperm count (millions/mL, SC) and percentage of mobile sperms were analyzed. Univariate and multivariate regression between the defined groups; bivariate regression analysis between age and sperm count and motility. Results: Number of patients: OS 78; LSL 85; RPS 204. Mean age 30.2 (SD 6.83); postoperative SC increased from 18.2 to 30.1 (CI 95% 27.3-32.9; p < 0,001); motility from 25.6 to 32.56% (30.9-34.2; p < 0.001). OS: SC varied from 16.9 to 18.2 (p < 0.001); sperm motility from 29% to 33% (p < 0.001). LSL: SC from 15.5 to 17.2 (p < 0.001); motility from 27 to 31% (p < 0.001). RPS: SC from 18.9 to 36.2 (p < 0.001); motility from 24% to 32% (p < 0.001). Univariate and multivariate analysis confirmed the significant difference of SC variation in RPS, compared to the other groups (p < 0.001). No significance between LSL and OS (p = 0.826). No significant differences regarding motility (p = 0.8). Conclusions: Varicocele correction is confirmed useful in improving sperm parameters; sclerotization technique leads to a better sperm improvement compared to other studied procedures; improvement in seminal parameters is not affected by age of the patients treated

Potential health effects of standing waves generated by low frequency noise

The main aim is to present the available updated knowledge regarding the potential health effects of standing waves generated by low frequency noise (LFN) from an open window in a moving car where the negative effects of LFN induced by heating components and/or heating, ventilation and air-conditioning are assessed. Furthermore, the assessment of noise in chosen enclosed spaces, such as rooms, offices, and classrooms, or other LFN sources and their effect on the human being were investigated. These types of noise are responsible for disturbance during relaxation, sleep, mental work, education, and concentration, which may reflect negatively on the comfort and health of the population and on the mental state of people such as scientific staff and students. The assessment points out the most exposed areas, and analyzes the conditions of standing wave generation in these rooms caused by outdoor and/or indoor sources. Measurements were made for three different enclosed spaces (office, flat, and passenger car) and sources (traffic specific noise at intersections, noise induced by pipe vibration, and aerodynamic noise) and their operating conditions. For the detection of LFN, the A-weighted sound pressure level and vibration were measured and a fast Fourier transform analysis was used. The LFN sources are specified and the direct effects on the human are reported. Finally, this paper suggests the possibilities for the assessment of LFN and some possible measures that can be taken to prevent or reduce them

Determination of the State of Wear of High Contact Ratio Gear Sets by Means of Spectrum and Cepstrum Analysis

The paper presents basic procedures and methods used for determining the state of wear of high contact ratio (HCR) gear sets comparing frequency spectra and cepstra recorded throughout their lifetime tests, through vibro-acoustic diagnostics. After a study and calculation of characteristic frequencies, the authors experimentally measured the dynamical behavior of the gear sets in order to determine their frequency spectra. To gain additional information about possible damage, cepstrum was evaluated for each measurement as well. Experiments were carried out on a FZG back-to-back test gearbox, equipped with HCR test gears during their lifecycle. The frequency spectrum and cepstrum was assigned to a specific percentage of pitting occurrence. Analyzed values of amplitudes at mesh frequency components and their sidebands (as well as corresponding quefrencies) in the spectrum (and cepstrum) were compared and the state of wear was assigned to each frequency (quefrency) response. The results from lifetime tests of two gear sets indicate that by means of FFT (as well as cepstrum) analysis the incubational phase (i.e., a cavity origination under a surface in contact) of the gear fault can be determined. This is not possible using classical (e.g., visual) methods. Furthermore, it was observed that pitting and thermal scuffing are distinguishable also at higher harmonics (the fifth and even sixth), which can be also used as an indicator of gear damage. Vibro-acoustic diagnostics is a feasible nondisassembling method used for the investigation and prediction of gear failure level in HCR gear wheels. It is shown to be a reliable method capable of predicting failure earlier than a classical visual (disassembling) approach.</jats:p

Cells Involved in Urethral Tissue Engineering: Systematic Review

The urethra is part of the lower urinary tract and its main role is urine voiding. Its complex histological structure makes urethral tissue prone to various injuries with complicated healing processes that often lead to scar formation. Urethral stricture disease can affect both men and women. The occurrence of this pathology is more common in men and thus are previous research has been mainly oriented on male urethra reconstruction. However, commonly used surgical techniques show unsatisfactory results because of complications. The new and progressively developing field of tissue engineering offers promising solutions, which could be applied in the urethral regeneration of both men´s and women´s urethras. The presented systematic review article offers an overview of the cells that have been used in urethral tissue engineering so far. Urine-derived stem cells show a great perspective in respect to urethral tissue engineering. They can be easily harvested and are a promising autologous cell source for the needs of tissue engineering techniques. The presented review also shows the importance of mechanical stimuli application on maturating tissue. Sufficient vascularization and elimination of stricture formation present the biggest challenges not only in customary surgical management but also in tissue-engineering approaches