Stability of the fluid interface in a Hele-Shaw cell subjected to horizontal vibrations.

The stability of the horizontal interface of two immiscible viscous fluids in a Hele-Shaw cell subject to gravity and horizontal vibrations is studied. The problem is reduced to the generalized Hill equation, which is solved analytically by the multiple scale method and numerically. The long-wave instability, the resonance (parametric resonance) excitation of waves at finite frequencies of vibrations (for the first three resonances), and the limit of high-frequency vibrations are studied analytically under the assumption of small amplitudes of vibrations and small viscosity. For finite amplitudes of vibrations, finite wave numbers, and finite viscosity, the study is performed numerically. The influence of the specific natural control parameters and physical parameters of the system on its instability threshold is discussed. The results provide extension to other results [J. Bouchgl, S. Aniss, and M. Souhar, Phys. Rev. E 88, 023027 (2013)10.1103/PhysRevE.88.023027], where the authors considered a similar problem but took into account viscosity in the basic state and did not consider it in the equations for perturbations.

[PERCUTANEOUS CYSTOLITHOTRIPSY: THE FIRST CLINICAL EXPERIENCE].

This paper reviews results of examination and treatment for benign prostatic hyperplasia (BPH) and infravesical obstruction in 16 patients observed in Department of Urology of Zhukovsky CCH in 2013-2014. Most operated patients required particularly careful approach to the surgery planning due to advanced age and multiple comorbidities. Treatment of all patients was carried out in a single therapeutic session performed in two stages. Percutaneous cystolithotripsy was performed on the first stage and subsequently transurethral resection of the prostate (TURP) was carried out. It was found, that combination of minimally invasive percutaneous approach and TURP is the most sparing way to restore lower urinary tract urodynamics and eliminate bladder stones in all operated patients. With appropriate patient selection and a clear definition of indications, proposed treatment combination is a promising and effective strategy in management of patient with urolithiasis with infravesical obstruction and BPH.

[Transurethral contact electroimpulse ureteropyelolithotripsy].

Transurethral contact electroimpulse ureteropyelolithotripsy (TCEUT) was conducted in 161 patients aged 18 to 84 years (mean age 47 +/- 14 years) admitted to the urological department of Zhukovsky city hospital in 2006-2009. Female/male proportion 1.4:1. Overall efficacy of TCEUT was 98%, the concrement was destructed completely during the first TCEUT session in 98%, partially in 2% cases. The method was feasible in all the patients if the instrument could reach the concrement. Duration of the session providing complete elimination of the concrements varied from 1 to 6 months.Contact electroimpulse ureterolithotripsy is conducted with single impulses beginning with low energy (0.45 J). Contact electroimpulse pyelolithotripsy requires a higher initial impulse energy (0.6 J). TCEUT is a highly effective method of the treatment of concrements of the upper urinary tract. Side effects were registered in maximum 5%. Long-term existence of the concrement in the urinary system raises the risk of intraoperative complications.

[Transcutaneous nephrolithotripsy in presenile and senile patients].

A total of 323 transcutaneous roentgenoendoscopic operations were made in 212 patients from January 2000 to December 2009 including 96 operations in 81 presenile and senile patients (87 and 9 operations, respectively). Transcutaneous nephrolithotripsy (TCNT) eliminated concrement from the kidney for one session in 59 (72.8%) patients. It proved to be the most sparing treatment in serious clinical situations and provided maximally complete evacuation of the concrement from the kidney. A total complication rate was 14.8%. All the complications were cured with conservative pharmacotherapy. TCNT has the same indications as open surgery, is a method of choice in presenile and senile patients with large, stag-horn and recurrent concrements of the kidney, impacted pelvicoureteral concrements, in impaired renal urodynamics and high bacteriuria. TCNT can be used as a second-line treatment in failure of extracorporeal shock-wave lithotripsy or in combination with it (sandwich-therapy) for complete concrement elimination.