ПРИМЕНЕНИЕ ИТЕРАЦИОННОГО ДИНАМИЧЕСКОГО ПРОГРАММИРОВАНИЯ В ЗАДАЧАХ СИНТЕЗА ОПТИМАЛЬНОГО УПРАВЛЕНИЯ С ПОЛНОЙ ОБРАТНОЙ СВЯЗЬЮ

This paper presents a generalization of iterative dynamic programming using Luus-Jakola optimization procedure applied to the solution of optimal feed-back control for nonlinear deterministic systems. Iterative dynamic programming is realized. Efficiency of proposed method is tested on the software complex developed by the authors in C++; a model example of chemical process control is presented.В работе предложено обобщение процедуры итерационного динамического программирования с применением последовательной редукции множества допустимых решений (метода Luus-Jakola) на задачи оптимального управления нелинейными непрерывными детерминированными системами с полной обратной связью. Оно включает поиск коэффициентов представления закона управления функцией насыщения, учитывающей ограничения на величину управления, содержащей в качестве аргумента сумму произведений ортонормированных функций, образующих базисную систему. На основе предложенного алгоритма разработан комплекс программ, эффективность которого продемонстрирована на модельном примере управления химическим процессом

ПРИМЕНЕНИЕ ГИБРИДНОГО МЕТОДА СЛУЧАЙНОГО ПОИСКА В ЗАДАЧАХ ОПТИМИЗАЦИИ ЭЛЕМЕНТОВ ТЕХНИЧЕСКИХ СИСТЕМ

This paper presents a modification of the Luus-Jaakola global optimization method, which belongs to the class of metaheuristic algorithms. A hybrid method is suggested, using a combination of random search methods: Luus-Jaakola method, adaptive random search method and best trial method. The obtained method is applied to the optimization of parameters of different engineering systems. This class of problems appears during the design of aerospace and aeronautical structures; its goal is the cost or weight minimization of the construction. These problems belong to the class of constrained global optimization problems, where the level surface of the objective function has uneven relief and there is a large number of variables. This means that the classical optimization methods prove to be inefficient and these problems should be solved using metaheuristic optimization methods, which provide sufficient accuracy at reasonable operating time. In this paper, the constrained global optimization problem is solved using the penalty method. Thus, the problem of exterior penalty function optimization is considered, where the penalty coefficients are chosen in such a way as to avoid the violation of the constraints. Two applied problems are considered in the paper: the determination of the high-pressure vessel parameters and the anti rattle spring parameters determination. Using the suggested algorithm, a software complex was developed, which allows us to solve engineering optimization problems. The results obtained using the suggested methods were compared with the results obtained using the non-modified Luus-Jaakola method in order to demonstrate the efficiency of the suggested hybrid random search method.В работе предложена модификация метода случайного поиска с последовательной редукцией области исследования (метода Luus – Jaakola), относящегося к классу метаэвристических методов поиска глобального экстремума. Предложен гибридный метод глобальной оптимизации, основанный на совместном использовании метода случайного поиска с последовательной редукцией области исследования, метода адаптивного случайного поиска и метода поиска наилучшей пробы. Полученный модифицированный метод применен для решения прикладных инженерных задач оптимизации параметров технических систем. Этот класс задач возникает при проектировании ракетно-космических и авиационных конструкций. Целью таких задач является минимизация стоимости или веса рассматриваемой конструкции. Подобные задачи представляют собой задачи условной глобальной оптимизации со сложным рельефом поверхностей уровня целевой функции и с большим числом переменных, что делает применение классических методов глобальной оптимизации малоэффективным, в то время как использование метаэвристических методов позволяет получить достаточно точное решение за приемлемое время. В работе решение задачи глобальной условной оптимизации происходит с использованием метода внешних штрафов. Выполняется переход к задаче оптимизации вспомогательной целевой функции, при этом параметры штрафа подбираются так, чтобы выполнялись наложенные ограничения, определяющие множество допустимых решений. В работе рассмотрены две прикладные задачи: определение параметров сосуда высокого давления и определение параметров натяжной/компрессионной пружины. На основе предложенного алгоритма разработан комплекс программ, решающих данные прикладные задачи, результаты работы которого сравниваются с результатами работы немодифицированного метода случайного поиска с последовательной редукцией области исследования и другими метаэвристическими алгоритмами. Сравнение полученных результатов демонстрирует эффективность предложенного метода

IMPROVEMENT OF TREATMENT OF UNFORMED DUODENAL AND HIGH JEJUNAL FISTULAS

This article shows many years of surgical experience of treatment of unformed duodenal and high jejunal fistulas using specific combined methods in main treatment group. The review covers the period from 2000 to 2016 years, which includes treatment of 132 patients who suffered from unformed duodenal and high jejunal fistulas. The research was conducted on the basis of the Republic Clinical hospital of G.G. Kuvatov in Bashkortostan. We followed the purpose of analysis and evaluation of the structure and quantity of early postoperative complications, including purulent-septic complications, as well as postoperative lethality, by comparing the main and control groups of treated patients, who received different kinds of therapy of unformed duodenal and jejunal fistulas. The treatment complex (main treatment group) consists of local use of collagen to strengthen intestinal sutures; selective injections of angioprotectors to blood vessels to improve microcirculation and trophic tissues; laser and antibiotic therapy for better eradication of microorganisms. The obtained results showed that the technique developed by us allowed to reduce the frequency of inconsistency of intestinal sutures, the number of newly formed intestinal fistula and purulent-septic complications in the treatment of patients with unformed duodenal and high jejunal fistulas

A new health care index predicts short term mortality for TB and HIV co-infected people

BACKGROUND: Using 2004–2007 TB:HIV Study data from Europe and Latin America, we previously generated a health care index (HCI) for TB and HIV co-infected people. With improvements in diagnostic and management practices, we have now updated the HCI with new data. METHODS: We evaluated nine aspects of health care in Cox proportional hazards models on time from TB diagnosis to death. Kaplan-Meier methods were used to estimate the probability of death by HCI quartile. RESULTS: Of 1396 eligible individuals (72% male, 59% from Eastern Europe), 269 died within 12 months. Use of rifamycin/isoniazid/pyrazinamide-based treatment (HR 0.67, 95% CI 0.50–0.89), TB drug susceptibility testing (DST) and number of active TB drugs (DST + <3 drugs (HR 1.09, 95% CI 0.80–1.48), DST + ≥3 drugs (HR 0.49, 95% CI 0.35–0.70) vs. no DST), recent HIV-RNA measurement (HR 0.64, 95% CI 0.50–0.82) and combination antiretroviral therapy use (HR 0.72, 95% CI 0.53–0.97) were associated with mortality. These factors contributed respectively 5, –1, 8, 5 and 4 to the HCI. Lower HCI was associated with an increased probability of death; 30% (95% CI 26–35) vs. 9% (95% CI 6–13) in the lowest vs. the highest quartile. CONCLUSION: We found five potentially modifiable health care components that were associated with mortality among TB-HIV positive individuals. Validation of our HCI in other TB cohorts could enhance our findings

Healthcare delivery for HIV-positive people with tuberculosis in Europe

Background In a 2013 survey, we reported distinct discrepancies in delivery of tuberculosis (TB) and HIV services in eastern Europe (EE) vs. western Europe (WE). Objectives To verify the differences in TB and HIV services in EE vs. WE. Methods Twenty-three sites completed a survey in 2018 (EE, 14; WE, nine; 88% response rate). Results were compared across as well as within the two regions. When possible, results were compared with the 2013 survey. Results Delivery of healthcare was significantly less integrated in EE: provision of TB and HIV services at one site (36% in EE vs. 89% in WE; P = 0.034), and continued TB follow-up in one location (42% vs. 100%; P = 0.007). Although access to TB diagnostics, standard TB and HIV drugs was generally good, fewer sites in EE reported unlimited access to rifabutin/multi-drug-resistant TB (MDR-TB) drugs, HIV integrase inhibitors and opioid substitution therapy (OST). Compared with 2013, routine usage of GeneXpert was more common in EE in 2018 (54% vs. 92%; P = 0.073), as was access to moxifloxacin (46% vs. 91%; P = 0.033), linezolid (31% vs. 64%; P = 0.217), and bedaquiline (0% vs. 25%; P = 0.217). Integration of TB and HIV services (46% vs. 39%; P = 1.000) and provision of OST to patients with opioid dependency (54% vs. 46%; P = 0.695) remained unchanged. Conclusion Delivery of TB and HIV healthcare, including integration of TB and HIV care and access to MDR-TB drugs, still differs between WE and EE, as well as between individual EE sites

АНАЛИЗ РАННИХ ОСЛОЖНЕНИЙ ПРИМЕНЕНИЯ БИОИМПЛАНТА PERMACOL В КОМБИНАЦИИ С СЕЛЕКТИВНЫМ ВВЕДЕНИЕМ ПРЕПАРАТА НИЦЕРГОЛИНА ПРИ КИШЕЧНЫХ СВИЩАХ

Introduction. Intestinal fistulas to date remain one of the unresolved surgical problems. If patients with low intestinal fistulas are treated roughly the same way by the majority of authors, then the most effective treatment of intestinal fistula of high localization remains controversial. In this context, the objective of the work was to improve the treatment of patients with unformed duodenal and high enteric fistulas by local administration of collagen coating with selective angiotropic effect.Materials and methods. The work involved open prospective randomized study including 109 patients admitted in purulent surgery Department of the Republican State Clinical Hospital named after G.G. Kuvatov (city of Ufa) for surgical treatment in the period 2000-2016. The main criterion to include patients in the study was the presence of duodenal and/or other enteric fistulas. All patients were randomly divided into two main groups: group of traditional therapy (68 patients), where, sealing of intestinal fistula was followed by standard pharmacological therapy; the study group (41 patients), where the sutures on intestine were strengthened with collagen with subsequent selective administration of angioprotectors and laser antibiotic therapy.Results. The findings show that the use of originally developed regimen leads to decreased suture failure from 39.5 to 17.0% and lethality from 37.5 to 19.5%. Conclusion. Local application of collagen in combination with selective lengthy administration of angioprotectors allows reducing the frequency of early postoperative complications and thereby improve patients’ health outcomes with unformed duodenal and high enteric fistulas. Введение. В современной хирургии кишечные свищи по сей день остаются одной из нерешенных хирургических задач. Если при низких кишечных свищах тактика ведения больных условно совпадает у большинства авторов, то наиболее эффективное лечение кишечных свищей высокой локализации остается спорным. В этой связи целью работы явилось совершенствование лечения пациентов с несформированными дуоденальными и высокими тонкокишечными свищами путем местного применения коллагенового покрытия с селективным ангиотропным воздействием.Материалы и методы. Было проведено открытое проспективное рандомизированное исследование, включающее 109 пациентов, поступивших в отделение гнойной хирургии Республиканской клинической больницы им. Г.Г. Куватова (г. Уфа) для оперативного лечения в период 2000-2016 гг. Основным критерием включения пациентов в исследование являлось наличие дуоденальных и/или других тонкокишечных свищей. Все пациенты случайным образом были распределены на две основные группы: группа традиционной терапии (68 пациентов), где после ушивания кишечных свищей выполнялась стандартная медикаментозная терапия; исследуемая группа (41 пациент), где для укрепления швов на кишке применялся коллаген с последующим селективным введением ангиопротекторов и лазероантибиотикотерапией.Результаты. По результатам проведенного исследования установлено, что применение оригинально разработанной схемы приводило к снижению несостоятельности швов с 39,5 до 17,0% и летальности с 37,5 до 19,5%.Заключение. Местное применение коллагена в сочетании с селективным длительным введением ангиопротекторов позволяет снизить частоту ранних послеоперационных осложнений и тем самым улучшить результаты лечения пациентов с несформированными дуоденальными и высокими тонкокишечными свищами.

Surgical Aid to Patients with Hepatopancreatobiliary Situations in Precovid Period and under Persistent Relapse of New Coronavirus Infection SARS-CoV-2

Introduction. The third wave of the new coronavirus infection (COVID-19) pandemic warrants total mobilisation of healthcare and social resources. In this respect, a pressing issue remains the provision of routine and emergency surgical care in patients with hepatopancreatobiliary diseases.Materials and methods. A retrospective analysis of the surgical outcomes in 5,040 hepatopancreatobiliary patients was carried out; this accounted for 51.1 % of the total abdominal surgeries.Results and discussion. Biliary lithiasis and its complications — choledocholithiasis with obstructive jaundice and residual choledocholithiasis — (54.4 %) as well as acute calculous cholecystitis (18.7 %) were operated most frequently. A sharp decrease over all hepatopancreatobiliary nosologies was registered for the surgical interventions in first pandemic year 2020. Thus, the median annual number of operations for biliary lithiasis and its complications was 550 (482–592 year-range) in the precovid period, while dropping to only 321 at the onset of pandemic (p &lt;0.05). A first sixmonth survey of year 2021 revealed a growth of surgical activity for all hepatopancreatobiliary nosologies.Conclusion. Hepatopancreatobiliary operations prevail (54.4 % cases) in the total structure of level 3 abdominal surgical interventions. A high annual rate of surgical operations over nearly all hepatopancreatobiliary nosologies was interrupted in the first year of the new coronavirus infection outbreak. Meanwhile, the first half of 2021 showed a clear tend towards restoring the precovid statistical indicators, despite the stressful conditions of persistently relapsing COVID-19 that surgical facilities had faced

Spinal trigeminal neurons demonstrate an increase in responses to dural electrical stimulation in the orofacial formalin test

Primary headaches are often associated with pain in the maxillofacial region commonly classified under the term “orofacial pain” (OFP). In turn, long-lasting OFP can trigger and perpetuate headache as an independent entity, which is able to persist after the resolution of the main disorder. A close association between OFP and headache complicates their cause and effect definition and leads to misdiagnosis. The precise mechanisms underlying this phenomenon are poorly understood, partly because of the deficiency of research-related findings. We combined the animal models of OFP and headache—the orofacial formalin test and the model of trigeminovascular nociception—to investigate the neurophysiological mechanisms underlying their comorbidity. In anesthetized rats, the ongoing activity of single convergent neurons in the spinal trigeminal nucleus was recorded in parallel to their responses to the electrical stimulation of the dura mater before and after the injection of formalin into their cutaneous receptive fields. Subcutaneous formalin resulted not only in the biphasic increase in the ongoing activity, but also in an enhancement of neuronal responses to dural electrical stimulation, which had similar time profile. These results demonstrated that under tonic pain in the orofacial region a nociceptive signaling from the dura mater to convergent trigeminal neurons is significantly enhanced apparently because of the development of central sensitization; this may contribute to the comorbidity of OFP and headache