Plasma hardening of heavily loaded parts of soil-cutting machines

The influence of plasma hardening on hardening processes of heavy-duty and, therefore, wear parts of working elements of soil-cutting machines has been studied. It is shown that surface plasma hardening of ploughshare made of structural steel 65Mn in the hardened zone with thickness of 0,8 mm leads to formation of gradient-layered (mixed) structure consisting of finely dispersed mixture decay products of fine-grained austenite with variable microhardness in the range of 760 – 395 HV. It is confirmed that the creation of gradient-layered structure and features of its formation after the surface plasma treatment are explained by ultrahigh heating and cooling rates, unattainable with traditional methods of heat treatment

Quantitative analysis of cell types during growth and morphogenesis in Hydra

Tissue maceration was used to determine the absolute number and the distribution of cell types in Hydra. It was shown that the total number of cells per animal as well as the distribution of cells vary depending on temperature, feeding conditions, and state of growth. During head and foot regeneration and during budding the first detectable change in the cell distribution is an increase in the number of nerve cells at the site of morphogenesis. These results and the finding that nerve cells are most concentrated in the head region, diminishing in density down the body column, are discussed in relation to tissue polarity

Femtosecond and Ultraviolet Laser Irradiation of Graphite-Like Hexagonal Boron Nitride

Effect of the femtosecond and nanosecond UV laser irradiation (below the ablation threshold) of graphite-like hexagonal boron nitride (hBN) has been studied. Experiments were carried out with the compacted powder under high vacuum at room temperature using excimer KrF laser (248 nm). In the nanosecond operation mode, the laser-induced fluorescence spectra are found strongly modified depending on the integrated doze, which is attributed to a progressive enrichment of the surface layer by elemental boron. A slow sample recovery after the laser irradiation has been observed. On the other hand, in the femtosecond mode the fluorescence spectra depend on the laser fluence, and the changes are reversible: low energy fluorescence spectra are restored immediately when the laser energy decreases. This effect can be explained by a material bleaching, which favors a bulk centers emission. The ablation threshold has been determined as 78 mJ/cm2 in the femtosecond laser operational mode

Near-term experiments and long-term goals at INURA pulsed ion accelerator in Nazarbayev University

Nazarbayev University works on establishing a research program on inertial confinement fusion, high energy physics and critical states of matter. Long term plans include building a new multi-MV, ~10 to several hundred GW/cm2 ion accelerator facility which will be used in studies of material properties at extreme conditions. Two design options are being considered..

Реконструкция молочной железы и лучевая терапия

In recent years there were significant advances in auto- and heterological breast reconstruction. Reconstruction with implants after mastectomy is being used more of ten. A recent study conducted by Albronoz et al, based on Nationwide Inpatient Sample data, found an increasing rate of immediate breast reconstruction with implants af ter mastectomy up to 11%, compared to autological methods of reconstruction [Barreau-Pouhaer L., 1992]. A possible reason for this increase is the growing number of young patients who need a mastectomy, but have not enough fat tissue for autological reconstruction. The purpose of reconstruction is to reach a long-term, oncologically safe and aesthetically pleasing result with reasonable operation expenses. Radiation therapy after mastectomy, as part of a complex treatment, is needed for an increasing amount of patients with breast cancer. Radiation therapy is a vital par t of cancer treatment, but often causes complications. Patients should be informed and consulted about potential complications so they can make reasonable decisions about their treatment.В последние годы отмечаются значительные продвижения в области ауто- и гетерологических реконструкций молочных желез. Реконструкция с помощью имплантатов при мастэктомии используется все чаще. Недавнее исследование, проведенное Albronoz с соавторами, на основе данных Nationwide Inpatient Sample с 1998 по 2008 год, выявило увеличение частоты одномоментных реконструкций имплантатами в среднем на 11% в год, по сравнению с аутологичными методами реконструкции [Barreau-Pouhaer L., 1992]. Возможной причиной для этого увеличения является растущее число молодых, нуждающихся в мастэктомии и не располагающих достаточной жировой клетчаткой для аутологичной реконструкции. Цель реконструкции – достичь долгосрочного, безопасного с онкологических позиций и эстетически удовлетворительного результата с рациональными затратами на операцию. Лучевая терапия после мастэктомии, как часть комплексного лечения, требуется все большему числу больных при раке молочной железы. Она, хотя и  является важнейшим  компонентом в лечении рака молочной железы, связана с высокой частотой возникновения осложнений. Следует надлежащим образом консультировать пациентово возможности этих потенциальных осложнений, с тем, чтобы они могли принимать обоснованные решения

Рекомендации по проведению тримодальной терапии рака мочевого пузыря (Невский консенсус 2021)

The aim of this work was to clarify and extend the existing clinical guidelines on organ-sparing treatment of muscleinvasive bladder cancer. The standard protocol of radical conservative treatment for muscle-invasive bladder cancer includes transurethral resection of the bladder, external beam radiotherapy with simultaneous chemotherapy (radiosensitization), which is usually referred to as trimodal therapy. The implementation of trimodal therapy into routine practice in Russia is limited due to the lack of distinct criteria for each of the stages. The involvement of surgeons, radiation oncologists, and chemotherapists, on the one hand, provides the required multidisciplinary approach to cancer treatment; on the other hand, it might impede the entire algorithm. To address this problem, specialists from the Department of Radiology (project moderators), Department of Cancer Urology, and Department of Chemotherapy of N.N. Petrov National Medical Research Center of Oncology under the auspices of Saint Petersburg Oncological Research Society formed a group of experts, including radiation oncologists, urologists, and chemotherapists from federal and local cancer (educational) institutions of Saint Petersburg who had an experience of treating muscle-invasive bladder cancer. The guideline was developed with the consideration of available guidelines published by leading professional associations of radiotherapy and oncology (urological), research articles, and own experience.         Цель работы – уточнение и дополнение клинических рекомендаций по органосохраняющему лечению мышечноинвазивного рака мочевого пузыря. Стандартный протокол радикального консервативного лечения мышечно-инвазивного рака мочевого пузыря включает трансуретральную резекцию мочевого пузыря, дистанционную лучевую терапию с одновременной химиотерапией (радиосенсибилизацию) и называется тримодальной терапией. Широкое внедрение тримодальной терапии в отечественную практику ограничено отсутствием четких критериев для каждого из этапов. Участие в протоколе хирургов, радиационных онкологов и химиотерапевтов, с одной стороны, обеспечивает необходимый мультидисциплинарный характер лечения онкологического больного, с другой – затрудняет реализацию всего алгоритма. Для осуществления поставленной задачи отделениями радиотерапии (модераторы проекта) и онкоурологии, а также отделением химиотерапии и инновационных технологий НМИЦ онкологии им. Н.Н. Петрова под эгидой Петербургского онкологического научного общества сформирована группа экспертов, включающая радиационных онкологов, онкоурологов и химиотерапевтов федеральных и городских онкологических (образовательных) учреждений (г. Санкт-Петербург), имеющих опыт лечения мышечно-инвазивного рака мочевого пузыря. Разработка рекомендаций велась с учетом имеющихся рекомендаций ведущих профессиональных радиотерапевтических и онкологических (урологических) ассоциаций, опубликованных статей и собственного опыта

БИОПСИЯ СИГНАЛЬНЫХ ЛИМФАТИЧЕСКИХ УЗЛОВ ПРИ РАКЕ МОЛОЧНОЙ ЖЕЛЕЗЫ

За последние десятилетия в хирургическом лечении рака молочной железы появилась тенденция к органосохраняющему и все менее травматичному и калечащему этапу в многоступенчатой терапии этого заболевания. Выполнение подмышечной лимфодиссекции часто сопровождается такими осложнениями, как лимфостаз верхних конечностей, ограничение подвижности и болевые ощущения плечевого сустава, что, в ряде случаев, ведет к инвалидизации, при излечении от рака

Giant resonant light forces in microspherical photonics

Resonant light pressure effects can open new degrees of freedom in optical manipulation with microparticles, but they have been traditionally considered as relatively subtle effects. Using a simplified two-dimensional model of surface electromagnetic waves evanescently coupled to whispering gallery modes (WGMs) in transparent circular cavities, we show that under resonant conditions the peaks of the optical forces can approach theoretical limits imposed by the momentum conservation law on totally absorbing particles. Experimentally, we proved the existence of strong peaks of the optical forces by studying the optical propulsion of dielectric microspheres along tapered microfibers. We observed giant optical propelling velocities ∼0.45 mm s−1 for some of the 15-20 µm polystyrene microspheres in water for guided powers limited at ∼43 mW. Such velocities exceed previous observations by more than an order of magnitude, thereby providing evidence for the strongly enhanced resonant optical forces. We analyzed the statistical properties of the velocity distribution function measured for slightly disordered (∼1% size variations) ensembles of microspheres with mean diameters varying from 3 to 20 µm. These results demonstrate a principal possibility of optical sorting of microspheres with the positions of WGM resonances overlapped at the wavelength of the laser source. They can be used as building blocks of the lossless coupled resonator optical waveguides and various integrated optoelectronics devices