Method of determining the optimal settings of automatic excitation regulators of synchronous machines in EPS

The stability of the electric power system can be improved by forming of the correct settings of automatic exciting regulators. Currently, there is no unified methodology of automatic exciting regulators, so analysis of their impact is still an urgent task. The article describes the approach to solving above-mentioned problem, which combines several methods. Research based on Hybrid Real Time Simulator of EPS developed in Tomsk Polytechnic University

Clinically pathogenetic and prognostic value of factors of diabetic retinopathy progression associated with essential hypertension after phacoemulsification

Purpose. To study clinical features of ophthalmic and laboratory changes after cataract phacoemulsification in patients with diabetic retinopathy associated with hypertension.Material and methods. It was selected 130 patients with the diagnosis of complicated cataract, non-proliferative diabetic retinopathy and they were divided into 3 groups: the group I – patients with non-proliferative diabetic retinopathy without hypertensive disease, the group II – patients with non-proliferative diabetic retinopathy and hypertension, who took angiotensin-converting enzyme (ACE) inhibitors, the group III – patients who took other antihypertensive drugs (a1-adrenoblockers and agonists I1-imidazoline receptors). The study included clinical and functional examinations: visometry, tonometry, refractometery, perimetry, bio-microscopy and direct ophthalmoscopy, optical coherence tomography, autofluorescence, UBM. Samples of lacrimal fluid and blood serum were collected. Clinical and laboratory parameters of homeostasis: endothelial factors, cytokines (IL-6, TGF-β, VEGF, PEDF), adhesion molecules: sICAM, sVCAM. All patients underwent micro-invasive cataract phacoemulsification with implantation of Acrysof Natural IOL (Alcon).Results. Based on the obtained results the stability of proand anti-angiogenic balance after phacoemulsification was determined in patients with diabetic retinopathy without hypertension. Opposite changes of proangiogenic potential were noted in the group of patients with diabetic retinopathy and hypertension after phacoemulsification. The group of patients with diabetic retinopathy and hypertension, who took angiotensin-converting enzyme inhibitors in the postoperative period showed an insignificant change of immune-bio-chemical indices early stabilized on the 3rd day, which allowed us to predict a favorable course of diabetic retinopathy. It is possible to ascertain a growth of pro-angiogenic potential and endothelial dysfunction by the nature of the changes in the balance of the studied parameters and to predict an aggravation of vascular changes in the group of patients with diabetic retinopathy and hypertensive disease, who received othergroups of drugs. All laboratory identified patterns were confirmed in the parallel dynamic ophthalmic studies which demonstrated a higher incidence of vascular disorders after phacoemulsification in patients with diabetic retinopathy and hypertension who were not treated with ACE inhibitors. Accordingly, a stable course of the disease clinically was observed in the group of patients treated with ACE inhibitors to normalize vascular hypertension. Conclusion. The performed evaluation of vascular changes factors after phacoemulsification and the effect of antihypertensive drugs on the balance of laboratory parameters in patients with diabetic retinopathy and hypertensive disease allowed to determine a beneficial effect of ACE inhibitors on the stability of the angiogenic potential. It can be assumed that a basis of the described picture is in pharmacological properties of ACE inhibitors which have a positive effect on the stabilization of the angiogenic potential and reduce endothelial dysfunction

Clinical, pathogenetic and prognostic value of diabetic retinopathy’s progression after phacoemulsification in patients with the essential hypertension

Purpose: to study the clinical and laboratory changes after phacoemulsification of the cataract in patients with diabetic retinopathy and essential hypertension as the comorbidity.Patients and methods: 130 patients were divided into 3 groups. Visometry, tonometry, refractometers, perimetry, biomicroscopy and direct ophthalmoscopy, optical coherence tomography, autofluorescence, ultrasound biomicroscopy were conducted. The samples of tear fluid and serum were collected. The clinical and laboratory parameters of homeostasis (endothelial factors, cytokines (IL-6, TGF-β, VEGF, PEDF)), adhesion molecules (sICAM, sVCAM) have been evaluated.Results: Stability of pro-and angiogenic balance has been defined after the phacoemulsification in patients with diabetic retinopathy without essential hypertension. Opposite changes proangiogenic potential has been observed in the group of patients with diabetic retinopathy and hypertension after phacoemulsification. Insignificant changes of immunobiochemical indicators were identified in patients, receiving Angiotensin-converting enzyme (ACE) inhibitors in postoperative period. It allows to predict a favorable course of disease. The changes in the balance of the evaluated parameters inpatients, receiving other medicines, were characterized with the increase of proangiogenic and endothelial dysfunction. It was a predictor of vascular changes. All identified laboratory patterns were confirmed by the parallel dynamic prospective ophthalmic studies that demonstrated a higher incidence of vascular disorders after phacoemulsification in patients with diabetic retinopathy and hypertension who were not taking ACE inhibitors. Accordingly, in patients treated with ACE inhibitors for the normalization of vascular hypertension, clinically stable course of disease has been noted.Conclusion: The assessment of changes in vascular factors after phacoemulsification and the impact of antihypertensive drugs on the balance of laboratory parameters in patients with diabetic retinopathy and hypertensive disease allowed to establish a beneficial effect of ACE inhibitors on the stability of the angiogenic potential. It can be assumed that the basis of the picture described pharmacological properties of ACE inhibitors is a positive influence on the stabilization of the angiogenic potential and reduce endothelial dysfunction

Neoadjuvant chemoradiotherapy for locally advanced rectal cancer with peritumoral abscesses and fistulas

Purpose: Rectal cancer patients who present with peritumoral abscesses and fistulas at the time of diagnosis may be denied chemoradiotherapy (CRT) as the safety is unknown. The aim of this study was to investigate the safety of preoperative CRT in this patient group. Methods: We performed a retrospective nested case–control study to compare outcomes between patients with locally advanced rectal cancer with peritumoral abscesses and fistulas (study group) and patients with T4 locally advanced rectal cancer with no evidence of abscesses and fistulas (control group). These groups were matched by treatment center and radiotherapy delivery method. All patients received 50–54 Gy of conventionally fractionated RT with concurrent chemotherapy. Primary endpoint was grade 3–5 toxicity (by National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI CTCAE). Secondary endpoints included postoperative morbidity, pathologic complete response (pCR), disease-free survival (DFS), and overall survival (OS) at 2 years. Results: A total of 33 patients were included in each group. Grade 3 toxicity was observed in 2 (6.1%) patients in the study group and 4 (12.1%) patients in the control group (p = 0.672). No patients developed grade 4–5 toxicity. Grade 3–4 Clavien–Dindo complications were observed in 5 (15.2%) patients in the study group and in 6 (18.2%) patients in the control group (p = 1.0). Pathologic CR was achieved in 3 (9.1%) and 5 (15.2%) patients, respectively (p = 0.708). Two-year OS was 78.3% vs. 81.8% (p = 0.944), 2‑year DFS was 62.8% vs. 69.7% (p = 0.693), respectively. Conclusion: The presence of peritumoral abscesses and fistulas in patients with locally advanced rectal cancer is not associated with increased toxicity or inferior clinical outcomes after preoperative CRT. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany