Planar channeling and quasichanneling oscillations in a bent crystal

Particles passing through a crystal under planar channeling experience transverse oscillations in their motion. As channeled particles approach the atomic planes of a crystal, they are likely to be dechanneled. This effect was used in ion-beam analysis with MeV energy. We studied this effect in a bent crystal for positive and negative particles within a wide range of energies in sight of application of such crystals at accelerators. We found the conditions for the appearance or not of channeling oscillations. Indeed a new kind of oscillations, strictly related to the motion of over-barrier particles, i.e. quasichanneling particles, has been predicted. Such oscillations, named planar quasichanneling oscillations, possess a different nature than channeling oscillations. Through computer simulation, we studied this effect and provided a theoretical interpretation for them. We show that channeling oscillations can be observed only for positive particles while quasichanneling oscillations can exist for particles with either sign. The conditions for experimental observation of channeling and quasichanneling oscillations at existing accelerators with available crystal has been found and optimized.Comment: 25 pages, 11 figure

simulation code for modeling of coherent effects of radiation generation in oriented crystals

We present the crystalrad simulation code, combining all the features of the crystal simulation code for simulations of charged particles trajectories in a bent crystal and the radcharm++ code for calculation of the radiation spectrum. The crystalrad code is based on Monte Carlo simulations of trajectories in the planar and axial electric field either in a straight, bent, or periodically bent crystal taking into account multiple and single Coulomb scattering on nuclei and electrons, nuclear scattering and ionization energy losses. The trajectories simulated are used for calculation of radiation spectra by the Baier-Katkov method. We compare our simulations with experimental data taken at MAMI (MAinzer MIkrotron) as well as give an example for a possible future study with sub-GeV electrons interacting with Si bent crystals

Clinical Recommendations of the Northwest Society for Enteral and Parenteral Nutrition, Interregional Association for Emergency Surgery, Russian Gastroenterological Association, Union of Rehabilitation Therapists of Russia and Russian Transplantation Society on Diagnosis and Treatment of Short Bowel Syndrome-Associated Intestinal Failure in Adults

Aim. Current clinical recommendations address the epidemiology, causes, clinical manifestations and pathogenesis of possible immediate and long-term complications, as well as the problematic issues related to treatment and rehabilitation of adult short bowel syndrome patients.Key points. Short bowel syndrome (SBS) is a symptom complex of impaired digestion caused by the reduction of small intestine absorptive surface and manifested by intestinal failure (IF) of various severity (maldigestion and malabsorption) developing into malnutrition and systemic somatogenic disorders. The vital strategic aspects of its treatment are the personalisation of liquid, macro- and micronutrients consumption as well as avoidance of intestinal failure- and parenteral nutrition-associated complications. Various nutritional support regimes and the indications for infusion therapy and maintenance parenteral nutrition are considered in this patient category, also in outpatient settings. To mitigate the dependence on intravenous fluid- and nutrient administration and attain enteral autonomy in SBS-IF patients, the use of recombinant glucagon-like peptide-2 (GLP-2) is justified as exerting a pronounced trophic effect on the epithelial regenerative potential as well as structural and functional adaptation of intestinal mucosa. The SBS-IF patients prescribed with home parenteral nutrition and/or their caregivers should be trained in a special programme that covers the catheter care, preparation of infusion solutions and nutrient mixture container, infusion pump operation as well as the prevention, recognition and management of complications. The main referral indications for small bowel transplantation (SBT) are: fast-progressing cholestatic liver disease-complicated irreversible intestinal failure; thrombosis of two or more central venous conduits used for parenteral nutrition; recurrent catheter-associated bloodstream infection.Conclusion. Current recommendations on diagnosis and treatment as well as the developed criteria of medical aid quality assessment are applicable at different levels of healthcare

Жировые эмульсии третьего поколения в составе парентерального питания оперированных онкологических больных

Objective: to study the efficacy of third- versus secondary-generation fatty emulsions as part of parenteral nutrition in patients operated on for gastric cancer. Subjects and methods. Envelope randomization was used to make up two groups, each comprising 10 patients, operated on for gastric cancer in the scope of gastrectomy. A control group received parenteral nutrition having the following components: Lipofundin MST/LST 20%, (500 ml daily) + Nutriflex 48/150 (B. Braun) (1000 ml daily, 1744 kcal/day). The study group patients were given Lipoplus 20% (500 ml daily) + Nutriflex 48/150 (1000 ml daily, 1745 kcal/day). Parenteral nutrition was used on postoperative days 1 to 5. Results. Nutritional status evaluation revealed a significant increase in the concentration of total protein and albumin in the control and study group patients on postoperative day 6. The use of both second- and third-generation fatty emulsions caused a significant increase in the concentration of triglycerides on day 6 after surgery; no differences were found between the groups. On day 6 following surgery, there was a significant decrease in IL-4 in both groups (p<0.05). At the same time the Lipofundin MST/LST group showed a significantly lower concentration of IL-4 than did the study group (p<0.05). After termination of a parenteral nutrition course, the study and control groups showed a significant decrease in one of the major pro-inflammatory cytokines — IL-6. Conclusion. In the study group, the serum anti-inflammatory activity of IL-4 was more evident than that in the control group and the proinflammatory activity (IL-6 concentration) decreased, which can support that as compared with the second-generation fatty emulsions, third-generation ones with a balanced omega 3 to omega-6 fatty acid ratio (1:2.7) had a normalizing effect on systemic inflammatory processes and cytokine balance with increased anti-inflammatory and reduced proinflammatory activities. Key words: third-generation fatty emulsions, omega-3/omega-6 fatty acids, pro and anti-inflammatory cytokines.Цель исследования . Изучить эффективность жировых эмульсий третьего поколения в составе парентерального питания больных, радикально оперированных по поводу рака желудка, в сравнении с жировыми эмульсиями второго поколения. Материал и методы. Путем рандомизации методом конвертов сформировано две группы по 10 пациентов в каждой, радикально оперированных по поводу рака желудка в объеме гастрэктомии. В контрольной группе использовали парентеральное питание в следующем составе: «Липофундин МСТ/ЛСТ» 20% — 500 мл в сутки + «Нутрифлекс 48/150» (B. Braun) — 1000 мл в сутки (1744 ккал/сут). Пациенты исследуемой группы получали «Липоплюс» 20% — 500 мл в сутки + «Нутрифлекс 48/150» — 1000 мл в сутки (1745 ккал/сут). Парентеральное питание применяли с первых по пятые послеоперационные сутки. Результаты. Оценка нутритивного статуса выявила достоверное повышение концентрации общего белка и альбумина на 6-е послеоперационные сутки у пациентов контрольной и исследуемой групп. Отмечена адекватная утилизация парентерального питания в обеих группах. Назначение жировой эмульсии, как второго, так и третьего поколения сопровождалось достоверным повышением концентрации триглицеридов на 6-е сутки после операции, при этом различий между группами не выявлено. Получено достоверное уменьшение IL-4 на 6-е сут после операции в обеих группах (

Консервативное лечение ятрогенного разрыва трахеи (клинический случай)

The objective was to demonstrate a clinical case of iatrogenic injury of the trachea, which, despite its large size (length 65, width up to 25 mm), wastreated conservatively and, thus, avoided risks for the patient associated with the need for technically complex surgical intervention.Materials and methods. A 65-year-old patient diagnosed with peripheral cancer of the lower lobe of the left lung pT2aN0M0 stage IB, who routinely underwent thoracoscopic left lower lobectomy with mediastinal lymph node dissection. During anesthesia, tracheal intubation with a double-lumen tube of the R. Shaw type was carried out with technical difficulties; during intubation, a defect in the posterior wall of the trachea in its membranous part was formed. The defect was diagnosed on the first postoperative day.Results. Despite the large size of the tracheal defect, the patient had no symptoms of respiratory failure, and there were also no signs of mediastinitis or damage to the esophagus, which almost completely covered the resulting hole in the posterior wall of the trachea. Such circumstances made it possible to avoid a potentially dangerous and complex surgical intervention, carry out conservative therapy and wait for the resulting defect to heal through granulation tissue. Enhanced antimicrobial therapy was carried out; in order to sanitize the tracheobronchial tree and monitor healing, fiber-optic bronchoscopy was performed, which made it possible to clearly demonstrate both the damage itself and the stages of its healing.Conclusions. The described case clearly demonstrates the potential for healing of even very extensive tracheal wall defects with conservative therapy. However, it is important to note that success in this clinical case was the result of a combination of circumstances – only the membranous part of the trachea was damaged; the defect was almost completely covered by the intact esophagus, which reduced the risk of developing mediastinitis and prevented the development of severe pneumomediastinum and subcutaneous emphysema. There were no signs of respiratory failure. The patient was transferred from the intensive care unit on the 13th day of the postoperative period, discharged from the hospital on the 22nd day.Цель – продемонстрировать клинический случай ятрогенного повреждения трахеи, которое, несмотря на крупные размеры (длина 65, ширина до 25 мм), удалось излечить консервативно и, таким образом, избежать рисков для пациента, связанных с необходимостью проведения технически сложного оперативного вмешательства.Материалы и методы. Пациенту 65 лет с диагнозом «Периферический рак нижней доли левого легкого T2aN0M0 IB стадия» в плановом порядке выполнена торакоскопическая нижняя лобэктомия слева с медиастинальной лимфодиссекцией. В ходе анестезии с техническими трудностями проведена интубация трахеи двухпросветной трубкой типа Robertshaw, приведшая к образованию дефекта задней стенки трахеи в мембранозной ее части. Дефект диагностирован в первые послеоперационные сутки.Результаты. У пациента, несмотря на большой размер дефекта трахеи, отсутствовали явления дыхательной недостаточности, а также не было признаков медиастинита и повреждения пищевода, который почти полностью прикрывал образовавшееся отверстие в задней стенке трахеи. Такие обстоятельства позволили избежать потенциально опасного и сложного оперативного вмешательства, провести консервативную терапию и дождаться заживления образовавшегося дефекта через грануляционную ткань. Проводили усиленную антимикробную терапию; с целью санации трахеобронхиального дерева и контроля заживления выполняли фибробронхоскопию, что позволило наглядно продемонстрировать и собственно повреждение, и этапы его заживления.Выводы. Описываемый случай демонстрирует потенциальную возможность заживления даже весьма обширных дефектов стенки трахеи при проведении консервативной терапии. Однако важно отметить, что успех в данном клиническом случае был результатом стечения ряда обстоятельств – повреждена была только мембранозная часть трахеи; дефект практически полностью был прикрыт неповрежденным пищеводом, что уменьшило риск развития медиастинита, предотвратило развитие обширных пневмомедиастинума и подкожной эмфиземы. Также отсутствовали явления дыхательной недостаточности. Пациент был переведен из отделения реанимации и интенсивной терапии на 13-е сутки послеоперационного периода, выписан из стационара на 22-е сутки

KLEVER: An experiment to measure BR(KL→π0ννˉK_L\to\pi^0\nu\bar{\nu}) at the CERN SPS

Precise measurements of the branching ratios for the flavor-changing neutral current decays $K\to\pi\nu\bar{\nu}$ can provide unique constraints on CKM unitarity and, potentially, evidence for new physics. It is important to measure both decay modes, $K^+\to\pi^+\nu\bar{\nu}$ and $K_L\to\pi^0\nu\bar{\nu}$, since different new physics models affect the rates for each channel differently. The goal of the NA62 experiment at the CERN SPS is to measure the BR for the charged channel to within 10%. For the neutral channel, the BR has never been measured. We are designing the KLEVER experiment to measure BR($K_L\to\pi^0\nu\bar{\nu}$) to $\sim$20% using a high-energy neutral beam at the CERN SPS starting in LHC Run 4. The boost from the high-energy beam facilitates the rejection of background channels such as $K_L\to\pi^0\pi^0$ by detection of the additional photons in the final state. On the other hand, the layout poses particular challenges for the design of the small-angle vetoes, which must reject photons from $K_L$ decays escaping through the beam exit amidst an intense background from soft photons and neutrons in the beam. Background from $\Lambda \to n\pi^0$ decays in the beam must also be kept under control. We present findings from our design studies for the beamline and experiment, with an emphasis on the challenges faced and the potential sensitivity for the measurement of BR($K_L\to\pi^0\nu\bar{\nu}$).Comment: 13 pages, 4 figures. Submitted as input to the 2020 update of the European Strategy for Particle Physics. v2: Included authors unintentionally omitted in v