Bhabha scattering at LEP1. Calorimeter event selection

Analitical calculations have been used to describe the calorimeter event selection in small-angle electron-positron scattering at LEP1. The first-order QED correction to the Born cross-section has been derived with leading log and the next-to-leading log approximations. The second- and the third-order corrections were computed with leading accuracy. The present analytical results are illustated by Tabeles and compared with the corresponding results obtained with the Monte Carlo generator BHLUMI.Comment: 26p., submitted to Journ. of Physics

Origin of Jahn-Teller distortion and orbital-order in LaMnO3

The origin of the cooperative Jahn-Teller distortion and orbital-order in LaMnO3 is central to the physics of the manganites. The question is complicated by the simultaneous presence of tetragonal and GdFeO3-type distortions and the strong Hund's rule coupling between e_g and t_2g electrons. To clarify the situation we calculate the transition temperature for the Kugel-Khomskii superexchange mechanism by using the local density approximation+dynamical mean-field method, and disentangle the effects of super-exchange from those of lattice distortions. We find that super-exchange alone would yield T_KK=650 K. The tetragonal and GdFeO3-type distortions, however, reduce T_KK to 550 K. Thus electron-phonon coupling is essential to explain the persistence of local Jahn-Teller distortions to at least 1150 K and to reproduce the occupied orbital deduced from neutron scattering.Comment: 4 pages, 3 figures; published version (minor changes

Understanding Anomalous Transport in Intermittent Maps: From Continuous Time Random Walks to Fractals

We show that the generalized diffusion coefficient of a subdiffusive intermittent map is a fractal function of control parameters. A modified continuous time random walk theory yields its coarse functional form and correctly describes a dynamical phase transition from normal to anomalous diffusion marked by strong suppression of diffusion. Similarly, the probability density of moving particles is governed by a time-fractional diffusion equation on coarse scales while exhibiting a specific fine structure. Approximations beyond stochastic theory are derived from a generalized Taylor-Green-Kubo formula.Comment: 4 pages, 3 eps figure

HEART RATE VARIABILITY IN HEMODIALYSIS PATIENTS

There are a small number of works that have studied heart rhythm variability parameters in patients treated with hemodialysis. Aim. To investigate the peculiarities of heart rhythm variability parameters in patients treated with hemodialysis. Methods. The observational controlled study included 55 patients treated with hemodialysis, aged 24 to 75 years, including 29 men and 26 women. The control group consisted of 20 healthy individuals of comparable age and sex. Heart rhythm variability parameters were investigated in all patients. Results. In the study of heart rhythm variability in patients treated with hemodialysis comparatively with the control group time parameters and most of frequency indexes were decreased. Conclusions. Our study found the diminishment of the total power of neurohumoral regulation in patients treated hemodialysis, as evidenced by the low values SDNN, rNN50, CV

THE PREDICTORS OF HOSPITALIZATION IN HEMODIALYSIS PATIENTS

Summary. The aim of the present research was to identify predictors of hospitalization hemodialysis (HD) patients. Materials and methods. The study involved 186 HD patients (49,38±0,94 у.) between Jan 2013 and Jan 2014. We studied the evolution of laboratory and treatment parameters, including dry body-weight, ultrafiltration, mean blood pressure, plasma albumin, Hb, absolute lymphocyte count, absolute neutrophil count, neutrophil-to-lymphocyte ratio, “hemoglobin variability ” all patients. The HD patients were divided for 2 groups: I group of outpatients (n=103), II group of hospitalized patients (n=83). Data from 83 hospitalized patients were compared with non-hospitalized patients. Laboratory and treatment parameters were assessed at least 3 months prior to admission. Results. We found that hospitalization was 45,29±4,20 days, frequency of hospitalization 1,46±0,07. The likelihood of frequency and duration a hospitalization increased with patient age (p<0,05). Hospitalizations were preceded by a decrease level albumin, a decline in Hb concentration, a decrease absolute lymphocyte count, increase in the neutrophil-to-lymphocyte ratio, a reduction ultrafiltration. The hozpitalization of patients with “stable hemoglobin ” was significantly lower than in patients with “low of hemoglobin variability”(p<0,005). Conclusions. Patients whose noted these parameters should be monitored, thus, it may be useful to identify risk factors for hospitalization

КЛІНІЧНА ЕФЕКТИВНІСТЬ НЕФРОТЕКТА У ГЕМОДІАЛІЗНИХ ПАЦІЄНТІВ

Пациенты на гемодиализе составляют большую группу, которая получает искусственное питание. Нутриционная программа для этих пациентов рассматривает не только метаболические нарушения, связанные с почечной недостаточностью и сопутствующими осложнениями, а и нарушения нутриционного баланса, обусловленные процедурой гемодиализа

INFLUENCE OF EPOETIN ALFA ON LEVEL OF PROINFLAMMATORY AND ANTIINFLAMMATORY CYTOKINE OF PATIENTS IN MAINTENCE HEMODIALYSIS

Summary. The aim of the present research was to study the influence of еpoetin alfa to the level of pro- and anti-inflammatory cytokines in patients with anemia treated by hemodialysis (HD). Materials and methods: We examined 73patients with anemia treated by hemodialysis (mean age 45,85 ±1,21 years). Patients were divided into 2groups: I group - comparison (n = 32), II group - treatment by epoetin alfa (n = 41). The levels of hemoglobin, C-reactiveprotein, ferritin, albumin, pro-and anti-inflammatory cytokines were determined before and after treatment in patients of both groups. The duration of treatment was 5 months. Results: Epoetin alfa increases Hb levels in patients treated by HD. After epoetin alfa applying reduction of proinflammatory cytokines ( TNF -a, IL -ip, IL -17, IL -18) and increased levels of IL -10 were observed. Conclusions: The clinical efficacy of the epoetin alfa treatment at the moment of completion of treatment was 75.6% (level of Hb > 110 g/L ). Epoetin alfa, improving the level of Hb, reduces the activity of chronic inflammation

A family of Nikishin systems with periodic recurrence coefficients

Suppose we have a Nikishin system of $p$ measures with the $k$th generating measure of the Nikishin system supported on an interval \Delta_k\subset\er with $\Delta_k\cap\Delta_{k+1}=\emptyset$ for all $k$. It is well known that the corresponding staircase sequence of multiple orthogonal polynomials satisfies a $(p+2)$-term recurrence relation whose recurrence coefficients, under appropriate assumptions on the generating measures, have periodic limits of period $p$. (The limit values depend only on the positions of the intervals $\Delta_k$.) Taking these periodic limit values as the coefficients of a new $(p+2)$-term recurrence relation, we construct a canonical sequence of monic polynomials $\{P_{n}\}_{n=0}^{\infty}$, the so-called \emph{Chebyshev-Nikishin polynomials}. We show that the polynomials $P_{n}$ themselves form a sequence of multiple orthogonal polynomials with respect to some Nikishin system of measures, with the $k$th generating measure being absolutely continuous on $\Delta_{k}$. In this way we generalize a result of the third author and Rocha \cite{LopRoc} for the case $p=2$. The proof uses the connection with block Toeplitz matrices, and with a certain Riemann surface of genus zero. We also obtain strong asymptotics and an exact Widom-type formula for the second kind functions of the Nikishin system for $\{P_{n}\}_{n=0}^{\infty}$.Comment: 30 pages, minor change

Blood vitamins status in patients with stages 2-5 chronic kidney disease

Patients with chronic kidney disease (CKD) are prone to development hypovitaminosis due to dietary constraints, diseases of the gastrointestinal tract, comorbid conditions, etc. Determination of vitamins level in patients with CKD will allow timely correction of their deficiency, prevent the development of hypervitaminosis and reduce oxidative stress. The purpose of the study was to examine the level of vitamins depending on the stage of CKD. Methods. Vitamin D levels (level 25-hydroxyvitamin D), A, E, B12, K, folic acid were determined in 44patients with CKD stages II-V(mean age 54,63 ± 2,63 years, 24 men 55%). According to the study, patients should not have received any drugs or biologically active additives containing vitamins for 3 months. Results. There was no significant difference in the level of studied vitamins in CKD st. II-III. There was a significant decrease in the levels of vitamin K, folic acid, and vitamin D levels with the progression of CKD. Vitamin A levels in CKD st. IV, V compared to CKD st. II were significantly higher. Considering large number drugs containing vitamins and trace elements and wide uncontrolled use in the population, in particular in patients with CKD, it is important to continue to study the levels of vitamins and trace elements in patients at different stages of the CKD, depending on the CKD nosology. Study of efficiency and safety applying vitamins in patients with CKD, particularly in the late stages of CKD, are appropriate. Conclusions. For patients with CKD characteristic of vitamins deficiency (in our study vitamin K, folic acid), but also an increase in their levels (vitamins A and E). Progression of CKD is accompanied by a change in the levels of vitamins. A significant decrease in the level of vitamin K, folic acid, vitamin D was notedfor patients with GFR <30 ml/min/1.73 m2

Рівень пролактину у пацієнтів з ХХН V стадії, які лікуються гемодіалізом

Розповсюдженість гіперпролатинемії у пацієнтів, які лікуються гемодіалізом (ГД), становить 30-65%. Метою нашої роботи було дослідити рівень пролактину (ПЛ) у пацієнтів з хронічною хворобою нирок (ХХН) V стадії, які лікуються ГД. Матеріали та методи. Відкрите проспективне нерандомізоване дослідження за участю 43 пацієнтів з ХХН VД стадії, які лікуються гемодіалізом. Критеріями включення пацієнтів до дослідження були: інформована згода хворого прийняти участь у дослідженні, лікування ГД понад трьох місяців, Кt/V>1,2; судинний доступ АВ-фістула. Критеріями виключення були: відмова хворого від участі у дослідженні, цироз печінки, гострі гепатити В, С, гіпотиреоз, гострий коронарний синдром, гостре порушення мозкового кровообігу, вагітність, пацієнти з злоякісними новоутвореннями; ті хто, системно отримує такі медикаменти, як трициклічні антидепресанти, інгібітори моноамінооксидази, резерпін, метилдопу, похідні фенотіазину, протиблювотні препарати (зокреама метоклопрамід), інгібітори синтезу дофаміну, нейролептики. Всім хворим проводили визначення ПЛ в сироватці крові. Результати. У хворих, які лікуються ГД констатовано підвищений рівень ПЛ у 32 (74%) пацієнтів. Рівень ПЛ сироватки крові у хворих, які лікуються ГД, був вищим порівняно з групою контролю: 47,17 ± 32,4 проти 11,76 ± 4,33нг/мл (р<0,001). Порушення місячного циклу склало 85% у групі жінок з підвищеним рівнем ПЛ проти 20% у жінок з нормальним рівнем ПЛ (р<0,05). У групах жінок та чоловіків з підвищеним рівнем ПЛ достовірно нижчий рівень Нb (р<0,05). Встановлено, що рівень ПЛ мав негативний кореляційний зв'язок з рівнем Нb(r=-0,36; p=0,02) та позитивний кореляційний звʼязок між рівнем ПЛ та СРБ (r=0,32; p=0,03). Висновки. Розповсюдженість гіперпролактинемії в нашому дослідженні склала 74%. Порушення менструального циклу зустрічалося достовірно частіше у жінок з гіперпролактинемією (85% проти 20%). Підвищення концентрації ПЛ має негативний зв'язок з рівнем Нb та позитивний зв'язок з рівнем СРП, що дозволяє припускати причетність ПЛ до процесів хронічного запалення