[Safety and efficiency of retrograde intrarenal surgery without X-ray guidance].

INTRODUCTION: The main stages of flexible ureteroscopy in patients with renal stones are usually performed under X-ray guidance. Long-term exposure of ionizing radiation can have negative effects on the patients with nephrolithiasis and the operating team. AIM: To study the results of retrograde intrarenal surgery (RIRS) without fluoroscopic guidance. MATERIALS AND METHODS: The results of flexible ureteroscopy (fURS) without X-ray-guidance in 76 patients were analyzed. There were 46 (53.3%) men and 30 (46.7%) women. The average age was 50.4+/-14.6 years. All patients underwent laboratory tests and non-contrast-enhanced computed tomography to determine the size and density of the stone. In all cases, preoperative ureteral stenting was performed. The average stone size was 10.5+/-4.2 mm. First, ureteroscopy with a rigid endoscope was done to assess the ureter and determine the depth of the introducing ureteral access sheath. After removing the ureteroscope along the guidewire, a ureteral access sheath was put at this distance. An inspection of the collecting system and laser fragmentation of kidney stones were performed using a flexible ureteroscope. In 64 (84.2%) patients, a 4.7 Ch stent was put at the end of the procedure, while in the remaining 12 (15.8%) patients, a ureteral catheter was left for 1-2 days. The operation time, stone-free rate, and the number of intra- and postoperative complications were studied. RESULTS: All fURS were successful and performed without X-ray guidance. The average operation time was 42.5+/-8.0 minutes. After the first session, stone-free rate was 92.1% (70/76). In 6 (7.9%) cases, residual stones were found, which were completely removed after the second session. Intraoperative complications, namely perforation of the upper calyx by the distal end of the ureteral access sheath, were observed in 2 (2.6%) patients, which did not require any additional interventions. Postoperative complications occurred in 10 (13.2%) patients, including fever in 6 (7.9%) and hematuria in 4 (5.3%) cases. There were no serious complications, such as ureteral perforation or sepsis, and no blood transfusion was performed. CONCLUSION: Flexible ureteroscopy with laser lithotripsy can be performed safely and effectively without X-ray guidance.

Universal Landau pole.

Our understanding of quantum gravity suggests that at the Planck scale the usual geometry loses its meaning. If so, the quest for grand unification in a large non-Abelian group naturally endowed with the property of asymptotic freedom may also lose its motivation. Instead, we propose a unification of all fundamental interactions at the Planck scale in the form of a universal Landau pole, at which all gauge couplings diverge. The Higgs quartic coupling also diverges while the Yukawa couplings vanish. The unification is achieved with the addition of fermions with vector gauge couplings coming in multiplets and with hypercharges identical to those of the standard model. The presence of these particles also prevents the Higgs quartic coupling from becoming negative, thus avoiding the instability (or metastability) of the standard model vacuum.

[A systems approach to the study of the problem of suicide and the prospects for its use in forensic medicine]. / Sistemnyi podkhod k izucheniiu problemy suitsida i perspektivy ego ispol'zovaniia v sudebnoi meditsine.

Discusses the total system's approach to analysis of the problem of suicide with due consideration for the etiology. Assesses the prospects of using this approach in forensic medicine for predicting the time course and tendencies in the mortality structure for certain regions.