Interpretation of the line spectrum of classical symbiotic stars in the scenario for their prototype Z And

Results of the study of the symbiotic binary Z And during its recent active phase 2000 -- 2010 when it experienced a series of six optical outbursts are presented. High-resolution spectra obtained during the first and fourth outburst, which was the strongest one, have been analyzed. These data are compared with results of theoretical computations. The comparison provides information about the behaviour of the system during the entire active phase rather than during an individual outburst. In particular it was found fundamental difference between the first outburst, which opened the active phase, and the recurrent outbursts - namely, the presence of bipolar collimated optical outflow during some of the recurrent outbursts. A scenario that can explain all the spectroscopic phenomena observed during this active phase as well as previous active phases of Z And is proposed. The possibility to use this scenario for explanation of the line spectrum of other classical symbiotic stars during their active phases is motivated.Comment: 10 pages, 10 figures; to be published in AIP Conf. Proc., School and Workshop on SPACE PLASMA PHYSICS, Kiten, Bulgaria; corrected typo

Pattern electroretinography as an objective method for study the visual analyzer function in patients with diabetes mellitus with initial diabetic retinopathy

Цел: Целта на нашето проучване е да се изследва обективно функцията на зрителния анализатор чрез патерна електроретинография (ПЕРГ) при пациенти със захарен диабет (ЗД) с начална диабетна ретинопатия (ДР) и получените резултати да се сравнят с контролната група, както и според типа на диабета.Материал и методика: Изследвана е група от 81 човека (162 очи), от които 47 здрави лица (контроли) - 94 очи. Пациентите със ЗД са 34 (68 очи), от които със ЗД тип 1 са 11 лица и 23 са с тип 2 ЗД. Извършена е ПЕРГ. Основните показатели, които са отчетени при анализа на резултатите са латентни времена и амплитуди, отразяващи се на конфиrурацията на вълновите форми.Резултати: При сравнителния анализ на стойностите на компонентите на ПЕРГ с контролната група, както и според типа ЗД, се установиха значителни различия. При сравнителния анализ на стойностите на компонентите на ПЕРГ между пациенти със ЗД с ДР и контроли се установи, че двете групи статистически се различават по амплитудите на всички компоненти на ПЕРГ при всички отвеждания при 15o и 30o.При латентностите сигнификантни различия се установиха при компонент Р50 при всички отвеждания при 15o и 30o. Пациентите със ЗД имат сигнификантно по-удължени латентности и по-ниски амплитуди, в сравнение с контролната група. При сравнителния анализ според типа ЗД, сигнификантни различия се получиха при амплитуден компонент P50-N95 при 15o и30o при дясно око, което потвърждава асиметричното засягане на очите при ЗД. Амплитудите на ПЕРГ при ЗД тип 2 са сигнификантно по-ниски от тези на пациентите със ЗД тип 1.Заключение: ПЕРГ би могла да се използва като обективен метод за регистриране на ранни изменения във функцията на зрителния анализатор (ЗА) като усложнение на З)J,. Също така и за проследяване на промените в динамика, тъй като изследването е неинвазивно, безвредно, по-бързо, повторяемо и обективно, по-евтино в сравнение с флуоресцеиновата ангиография (ФА), оптината кохерентна томография (ОСТ) и ангио-ОСТ.Aim: The aim of the study was to examine objectively the visual analyzer function by pattern electroretinography (PERG) in patients with diabetes mellitus (DM) with initial diabetic retinopathy (DR) and to compare the results with the control group as well as according to the type of diabetes. Material and methods: A group of 81 people (162 eyes) were studied. Patients with DM were 34 (68 eyes), 11 patients with type 1 DM and 23 with type 2 DM. The control group consisted of 47 healthy individuals (94 eyes). PERG was performed. The main variables that were considered in the results analysis were the latency and amplitudes, reflecting the configuration of the wave forms.Results: The comparative analysis of PERG components between patients with DM with DR and controls as well as according to the type of DM demonstrated significant differences. In latencies, significant differences were found for component P50 at all electrode positions at 15o and 30o. Patients with DM had significantly longer latencies and lower amplitudes compared to the control group. In the comparative analysis according to the type of DM, significant differences were found in amplitude component P50-N95 at 15o and 30o in the right eye, which confirms the asymmetrical eye involvement in DM. The PERG amplitudes in type 2 DM were significantly lower than those of type 1 DM patients.Conclusion: PERG could be used as an objective method for registration of early changes in the visual analyzer function as a DM complication. Also, to monitor the changes in dynamics as it is non-invasive, harmless, faster, and less expensive than fluorescein angiography (FA), OCT and angio-OCT

The effectiveness of two silicone dressings for sacral and heel pressure ulcer prevention compared with no dressings in high‐risk intensive care unit patients: a randomized controlled parallel‐group trial

Background There is a high incidence of pressure ulcers in high-risk settings such as intensive care. There is emerging evidence that the application of dressings to pressure ulcer predilection areas (sacrum and heels) improves prevention strategies. Objectives To determine whether preventive dressings, applied to the sacrum and heels of high-risk patients in intensive care units, in addition to standard prevention, reduces the incidence of pressure ulcers. Methods Between June 2015 and July 2018, a randomized, controlled, two-arm, superiority pragmatic study was performed with a concealed 1 : 1 allocation to the intervention and control group. Patients assigned to the intervention group had dressings applied to the sacrum and heels. Results In total, 7575 patients were screened for eligibility and 475 patients were included and allocated to both groups. Finally, 212 patients in the intervention group and 210 in the control group were analysed. The mean age was 63 center dot 5 years and the majority of patients were male (65 center dot 4%). The cumulative pressure ulcer incidence category II and above was 2 center dot 8% in the intervention, and 10 center dot 5% in the control group (P = 0 center dot 001). Compared with the control group, the relative risk in the intervention group was 0 center dot 26 [95% confidence interval (CI) 0 center dot 11-0 center dot 62] and the absolute risk reduction was 0 center dot 08 (95% CI 0 center dot 03-0 center dot 13). Conclusions The results indicate that the application of dressings, in addition to standard prevention, in high-risk intensive care unit patients is effective in preventing pressure ulcers at the heels and sacrum. What's already known about this topic? Pressure ulcers are severe soft tissue injuries and wounds, which occur worldwide in all healthcare settings. Despite preventive interventions, pressure ulcers still develop. There is emerging evidence that dressings help to prevent pressure ulcers. What does this study add? The incidence of pressure ulcers in intensive care units among high-risk patients remains high. The application of dressings to the sacrum and heels, in addition to standard preventive measures, reduces the relative and absolute risks for the development of pressure ulcers. The application of preventive dressings at the heels and sacrum seems to be feasible in intensive care settings

A Study of an Outburst in the Classical Symbiotic Star Z And in a Colliding-Wind Model

Two-dimensional gas-dynamical modeling of the mass-flow structure is used to study the outburst development in the classical symbiotic star Z And. The stage-by-stage rise of the light during the outburst can be explained in the framework of the colliding winds model. We suggest a scenario for the development of the outburst and study the possible influence of the changes of the flow structure on the light of the system. The model variations of the luminosity due to the formation of a system of shocks are in good agreement with the observed light variations

Toward visualization of nanomachines in their native cellular environment

The cellular nanocosm is made up of numerous types of macromolecular complexes or biological nanomachines. These form functional modules that are organized into complex subcellular networks. Information on the ultra-structure of these nanomachines has mainly been obtained by analyzing isolated structures, using imaging techniques such as X-ray crystallography, NMR, or single particle electron microscopy (EM). Yet there is a strong need to image biological complexes in a native state and within a cellular environment, in order to gain a better understanding of their functions. Emerging methods in EM are now making this goal reachable. Cryo-electron tomography bypasses the need for conventional fixatives, dehydration and stains, so that a close-to-native environment is retained. As this technique is approaching macromolecular resolution, it is possible to create maps of individual macromolecular complexes. X-ray and NMR data can be ‘docked’ or fitted into the lower resolution particle density maps to create a macromolecular atlas of the cell under normal and pathological conditions. The majority of cells, however, are too thick to be imaged in an intact state and therefore methods such as ‘high pressure freezing’ with ‘freeze-substitution followed by room temperature plastic sectioning’ or ‘cryo-sectioning of unperturbed vitreous fully hydrated samples’ have been introduced for electron tomography. Here, we review methodological considerations for visualizing nanomachines in a close-to-physiological, cellular context. EM is in a renaissance, and further innovations and training in this field should be fully supported

Contemporaneous Observations of Direct and Raman Scattered O VI in Symbiotic Stars

Symbiotic stars are binary systems consisting of a hot star, typically a white dwarf, and a cool giant companion. The wind from the cool star is ionized by the radiation from the hot star, resulting in the characteristic combination of sharp nebular emission lines and stellar molecular absorption lines in the optical spectrum. Most of the emission lines are readily identifiable with common ions. However, two strong, broad emission lines at $\lambda\lambda$ 6825, 7082 defied identification with known atoms and ions. In 1989 Schmid made the case that these long unidentified emission lines resulted from the Raman scattering of the O VI resonance photons at $\lambda\lambda$ 1032, 1038 by neutral hydrogen. We present contemporaneous far-UV and optical observations of direct and Raman scattered O VI lines for nine symbiotic stars obtained with the Hopkins Ultraviolet Telescope (Astro-2) and various ground-based telescopes. The O VI emission lines are present in every instance in which the $\lambda\lambda$ 6825, 7082 lines are present in support of the Schmid Raman scattering model. We calculate scattering efficiencies and interpret the results in terms of the Raman models. Additionally, we measure the flux of the Fe II fluorescence line at $\lambda$1776, which is excited by the O VI line at $\lambda$1032, and calculate the first estimates of the conversion efficiencies of this process.Comment: 48 pages, 5 figure

The apicomplexan plastid and its evolution

Protistan species belonging to the phylum Apicomplexa have a non-photosynthetic secondary plastid—the apicoplast. Although its tiny genome and even the entire nuclear genome has been sequenced for several organisms bearing the organelle, the reason for its existence remains largely obscure. Some of the functions of the apicoplast, including housekeeping ones, are significantly different from those of other plastids, possibly due to the organelle’s unique symbiotic origin

A prebiotic intervention study in children with autism spectrum disorders (ASDs)

Different dietary approaches, such as gluten and casein free diets, or the use of probiotics and prebiotics have been suggested in autistic spectrum disorders in order to reduce gastrointestinal (GI) disturbances. GI symptoms are of particular interest in this population due to prevalence and correlation with the severity of behavioural traits. Nowadays, there is lack of strong evidence about the effect of dietary interventions on these problems, particularly prebiotics. Therefore, we assessed the impact of exclusion diets and a 6-week Bimuno® galactooligosaccharide (B-GOS®) prebiotic intervention in 30 autistic children. RESULTS: The results showed that children on exclusion diets reported significantly lower scores of abdominal pain and bowel movement, as well as lower abundance of Bifidobacterium spp. and Veillonellaceae family, but higher presence of Faecalibacterium prausnitzii and Bacteroides spp. In addition, significant correlations were found between bacterial populations and faecal amino acids in this group, compared to children following an unrestricted diet. Following B-GOS® intervention, we observed improvements in anti-social behaviour, significant increase of Lachnospiraceae family, and significant changes in faecal and urine metabolites. CONCLUSIONS: To our knowledge, this is the first study where the effect of exclusion diets and prebiotics has been evaluated in autism, showing potential beneficial effects. A combined dietary approach resulted in significant changes in gut microbiota composition and metabolism suggesting that multiple interventions might be more relevant for the improvement of these aspects as well as psychological traits

Local therapy of cancer with free IL-2

This is a position paper about the therapeutic effects of locally applied free IL-2 in the treatment of cancer. Local therapy: IL-2 therapy of cancer was originally introduced as a systemic therapy. This therapy led to about 20% objective responses. Systemic therapy however was very toxic due to the vascular leakage syndrome. Nevertheless, this treatment was a break-through in cancer immunotherapy and stimulated some interesting questions: Supposing that the mechanism of IL-2 treatment is both proliferation and tumoricidal activity of the tumor infiltrating cells, then locally applied IL-2 should result in a much higher local IL-2 concentration than systemic IL-2 application. Consequently a greater beneficial effect could be expected after local IL-2 application (peritumoral = juxtatumoral, intratumoral, intra-arterial, intracavitary, or intratracheal = inhalation). Free IL-2: Many groups have tried to prepare a more effective IL-2 formulation than free IL-2. Examples are slow release systems, insertion of the IL-2 gene into a tumor cell causing prolonged IL-2 release. However, logistically free IL-2 is much easier to apply; hence we concentrated in this review and in most of our experiments on the use of free IL-2. Local therapy with free IL-2 may be effective against transplanted tumors in experimental animals, and against various spontaneous carcinomas, sarcomas, and melanoma in veterinary and human cancer patients. It may induce rejection of very large, metastasized tumor loads, for instance advanced clinical tumors. The effects of even a single IL-2 application may be impressive. Not each tumor or tumor type is sensitive to local IL-2 application. For instance transplanted EL4 lymphoma or TLX9 lymphoma were not sensitive in our hands. Also the extent of sensitivity differs: In Bovine Ocular Squamous Cell Carcinoma (BOSCC) often a complete regression is obtained, whereas with the Bovine Vulval Papilloma and Carcinoma Complex (BVPCC) mainly stable disease is attained. Analysis of the results of local IL-2 therapy in 288 cases of cancer in human patients shows that there were 27% Complete Regressions (CR), 23% Partial Regressions (PR), 18% Stable Disease (SD), and 32% Progressive Disease (PD). In all tumors analyzed, local IL-2 therapy was more effective than systemic IL-2 treatment. Intratumoral IL-2 applications are more effective than peritumoral application or application at a distant site. Tumor regression induced by intratumoral IL-2 application may be a fast process (requiring about a week) in the case of a highly vascular tumor since IL-2 induces vascular leakage/edema and consequently massive tumor necrosis. The latter then stimulates an immune response. In less vascular tumors or less vascular tumor sites, regression may require 9–20 months; this regression is mainly caused by a cytotoxic leukocyte reaction. Hence the disadvantageous vascular leakage syndrome complicating systemic treatment is however advantageous in local treatment, since local edema may initiate tumor necrosis. Thus the therapeutic effect of local IL-2 treatment is not primarily based on tumor immunity, but tumor immunity seems to be useful as a secondary component of the IL-2 induced local processes. If local IL-2 is combined with surgery, radiotherapy or local chemotherapy the therapeutic effect is usually greater than with either therapy alone. Hence local free IL-2 application can be recommended as an addition to standard treatment protocols. Local treatment with free IL-2 is straightforward and can readily be applied even during surgical interventions. Local IL-2 treatment is usually without serious side effects and besides minor complaints it is generally well supported. Only small quantities of IL-2 are required. Hence the therapy is relatively cheap. A single IL-2 application of 4.5 million U IL-2 costs about 70 Euros. Thus combined local treatment may offer an alternative in those circumstances when more expensive forms of treatment are not available, for instance in resource poor countries