A research on models of the photosynthetic light response curves on the example of evergreen types of plants

ArticleThe peculiarities of CO2 exchange in the leaves of ornamental evergreen plant species that are common in the Southern coast of Crimea were studied: Nerium oleander L., Laurus nobilis L., Aucuba japonica Thunb., and Melissa officinalis L. The results of approximation of the most commonly used four models of PN/I curves with the measured data were compared. The values of the parameters , (), , , which were calculated from the modified Michaelis-Menten model in comparison with the measured values were higher by 5–15%, and those that were calculated by the hyperbolic tangent model – lower by 3–13%. The use of a modified rectangular hyperbola model, which is capable of describing the photoinhibition by the nonrectangular hyperbola and the modified nonrectangular hyperbola model, showed a high degree of adequacy of the proposed models for describing the true dependence between the rate of photosynthesis and the light intensity for Nerium oleander L., Laurus nobilis L., Aucuba japonica Thunb. and Melissa officinalis L. Measurements of CO2 exchange in leaves under similar environmental conditions showed significant differences in the parameters of the PN/I curves: the light compensation point, the rate of photosynthesis and dark respiration, light saturation, and quantum yield. The highest values of photosynthesis efficiency were observed in Nerium oleander, the lowest values in Aucuba japonica – the light saturation was noted at a very low photosynthetically active radiation. The lower values of the light compensation point and the saturation constants in Laurus nobilis and Aucuba japonica indicate their effective use of the photosynthetically active radiation, which allows them to survive in conditions of durable shade

ХИРУРГИЯ ХРОНИЧЕСКОГО КОЛОГЕННОГО ЗАПОРА

Has an overview of literature devoted to the problem  of surgical treatment of patients with chronic  constipation resistant to conservative therapy produced. The indications for surgical intervention, different approaches to the  option  of different surgical operations, advantages and deficiency  of the last are given too.Представлен обзор литературы, посвященный проблеме хирургического лечения пациентов с резистентной формой  хронического колостаза. Освещены показания к оперативному вмешательству, различные подходы  к выбору  варианта операции, а также их основные преимущества и недостатки

Анализ действия Т-лимфоцитов периферической крови больного на клетки почечно-клеточного рака в модельных системах

Background. The introduction of immunotherapy based on immune checkpoint inhibitors has significantly improve the effectiveness of kidney cancer treatment. Nevertheless, not all patients respond to such treatment and there are no reliable predictive markers. Therefore, the development of a model system for assessing the cellular immune response to a tumor seems to be an urgent task.Aim. Development of a model to assess the T-cell immune response was the focus of this study.Materials and methods. Primary tumor cell culture and peripheral blood T-cell fraction were obtained under standard sterile conditions. T-cell activation were perform via anti-CD3 and anti-CD28 antibodies. The cell index was assessed using the RTCA xCELLigence biosensor technology (ACEA Biosciences, USA).Results. Tumor and T-cells from the same patient were cultured together to assess the growth rate of the tumor cell population. Measurements were taken at 30-minute intervals. The duration of observation was 24 hours. It has been shown that non-activated T-cells do not affect the proliferative properties of cultured cancer cells. On the contrary, activated T-cells suppressed the proliferative properties of cancer cells, which was associated with an increase in the proportion of Т-cells carrying the HLA-DR receptor (CD3+HLA–DR+) because of activation. Tumor-specific T-cell activity can lead to three consequences: lack of effect, partial suppression of proliferative properties, and complete death of tumor cells. In the latter case, the absence of such cells was determined by flow cytometry.Conclusion. The developed approach makes it possible to evaluate the cytotoxic properties of T cells in relation to tumor cells in a particular patient. The advantage of this method is that the measurement can be carried out in the presence of immune checkpoint inhibitors. The proposed method may be useful for evaluating the treatment regimen within the framework of personalized therapy.Введение. Внедрение современных методов иммунной терапии на основе препаратов, блокирующих иммунные контрольные точки, значительно повысило эффективность лечения. В то же время не у всех больных наблюдается ответ на такое лечение и надежные предиктивные маркеры отсутствуют. Создание модельной системы для оценки Т-клеточного иммунного ответа на опухоль представляется актуальной задачей.Цель исследования – создание модельной системы для оценки Т-клеточного иммунного ответа на клетки рака почки больного.Материалы и методы. Первичную культуру из опухолевой ткани светлоклеточного рака почки получали в стандартных стерильных условиях клеточного бокса. Фракцию Т-клеток периферической крови выделяли из мононуклеарных клеток. Активацию Т-клеток проводили с помощью антител к CD3 и CD28. Оценку изменения показателя «клеточный индекс» выполняли с применением биосенсорной технологии RTCA хCELLigence (ACEA Biosciences, США).Результаты. Полученные клетки опухоли и фракцию Т-клеток от того же больного культивировали совместно в течение 24 ч, анализируя изменения численности клеточной популяции с интервалом 30 мин. Показано, что неактивированные Т-клетки не влияют на пролиферативные свойства культивируемых раковых клеток, в то время как активированные Т-клетки подавляли пролиферативные свойства раковых клеток, что связано с увеличением доли Т-клеток, несущих рецептор HLA-DR (CD3+HLA–DR+) вследствие активации. Оцениваемая опухольспецифичная активность Т-клеток может отсутствовать, проявляться частичным подавлением пролиферативных свойств или приводить к полной гибели опухолевых клеток. В последнем случае отсутствие таких клеток подтверждали методом проточной цитометрии.Заключение. Разработанная система позволяет оценить эффективность действия иммунных Т-клеток для конкретного больного, в том числе в присутствии ингибиторов иммунных контрольных точек, что может быть использовано в качестве прогностической оценки при выборе средств лечения

Detection of π+π−\pi^+\pi^-atoms with the DIRAC spectrometer at CERN

The goal of the DIRAC experiment at CERN is to measure with high precision the lifetime of the $\pi^+\pi^-$ atom ($A_{2\pi}$), which is of order $3\times10^{-15}$ s, and thus to determine the s-wave $\pi\pi$-scattering lengths difference $|a_{0}-a_{2}|$. $A_{2\pi}$ atoms are detected through the characteristic features of $\pi^+\pi^-$ pairs from the atom break-up (ionization) in the target. We report on a first high statistics atomic data sample obtained from p Ni interactions at 24 GeV/$c$ proton momentum and present the methods to separate the signal from the background.Comment: 19 pages, 12 figures, 1 tabl

Use of rubber seton in the treatment of anorectal fistulae

Aim. To determine the efficacy of brand new industrial synthetic material for surgical treatment of patients with complicated anal fistulae and advantages of its use for ligature method of chronic paraproctitis treatment. Methods. Between 2010 and 2017, 175 patients (average age 47 years) with extra- and transsphincteric fistula were treated with a ligature. The study group consisted of 67 patients treated with rubber seton, comparison group included 108 patients treated with nylon ligature. Results. The results of clinical use of two seton types for the treatment of rectal fistulae are presented. Rubber thread with circular section as seton was proved to be inexpensive and effective material, advantages of which result from its physical properties. Thus, dissection of muscle tissue due to rubber elasticity becomes more efficient due to the greater reserve of compression than in case of rigid nylon seton, and that reduces the number of contractions. In addition, physical properties of the material, such as its high surface wettability, offer good drainage, and homogeneity of the material not absorbing the fluids, in turn, provides avoidance of the «wick effect» with the spread of infection into the wound. So, the treatment of anorectal fistulae with ligature with the use of rubber seton demonstrates the best therapeutic results and is preferable for patients. Conclusion. Use of rubber seton in treatment of complicated anal fistulae allows reducing hospital stay, provides better drainage of the surgical wound, and reducing the number of complications and required contractions, thus, minimizing the associated pain syndrome

What Has Changed in the Structure of Revision Hip Arthroplasty?

The key aspects of the study: 1) what has changed in the structure of revisions in recent years? 2) what is the spectrum of reasons for revision after primary hip arthroplasty and re-revision? 3) what are the demographic features of patients’ population undergoing the revision? Materials and methods. The authors conducted a retrospective evaluation of 2415 hip revision cases during the period of time from 2014 until 2018. Separately the authors assessed revisions after primary surgeries and re-revisions as well as the group of early revisions. Results. In the period from 2014 until 2018 the overall share of revisions was 16,6% from all total hip arthroplasties, at the same time the authors reported the absolute 1.7 times increase in number of revisions as well as increased share of revisions in the total structure of hip arthroplasty from 12,5% to 18,9% without significant variances in the number of primary procedures. The share of early revisions increased from 32.9% in 2013 to 56.7% while the number of early revisions amounted to 37.4% of all primary revisions. Gender composition in primary and revision hip arthroplasty varied insignificantly. Mean age at the moment of hip revision was 59.2% (95% CI from 58.7 to 59.7; Me 60 years) which is slightly less than in primary replacement — 60.2 years (95% CI from 58.9 to 61.1; Me 62 years), but such variances had a high statistical significance, р<0.001. The main reasons for primary revisions were aseptic loosening of prosthesis components (50.3%), infection (27.6%), polyethylene wear and osteolysis (9.0%) as well as dislocations (6,2%). Re-revisions structure featured prevalence of infection (69.0%), aseptic loosening (20.8%) and dislocations (7,8%). Mean period of time after primary hip arthroplasty to revision was 7.9 years (95% CI from 7.7 to 8.2; Me 7.3), to first re-revision — 2.9 (95% CI from 2.6 to 3.2; Me 1.2), to second re-revision — 2.2 (95% CI from 1.8 to 2.7; Me 1.1), to third — 2,2 (95% CI from 1.7 to 2.8; Me 1.1), to fourth — 1.0 (95% CI from 0.6 to 1.3; Me 0.6), remaining cases demonstrated rather high heterogeneity. Conclusion. In the result of the present study the authors observed increased number of all revision hip arthroplasties, especially the share of early revisions within first five years from the moment of previous surgery. The most often reason for revision after primary hip arthroplasty was aseptic loosening of one or both components of prosthesis. Infection was the absolute leader in the group of re-revisions constituting over half of all reasons for secondary intervention

Search for superheavy hydrogen isotopes

Experimental search for superheavy hydrogen isotopes 6H and 7H was performed in the stopped pion absorption on 9Be and 11B nuclei. The structures in the missing-mass spectra were observed in the reaction channels 9Be(π-, pd )X and 11B(π-, p4He)X . Four states of 6H were proposed. Evidences for 7H formation were obtained in the reaction channels 9Be(π-, pp)X and 11B(π-, p3He)X