Architecture of the nuclear pore complex coat

The nuclear pore complex (NPC) constitutes the sole gateway for bidirectional nucleocytoplasmic transport. Despite half a century of structural characterization, the architecture of the NPC remains unknown. Here, we present the crystal structure of a reconstituted ~400 kDa coat nucleoporin complex (CNC) from S. cerevisiae at a 7.4-Å resolution. The crystal structure revealed a curved Y-shaped architecture and the molecular details of the coat nucleoporin interactions forming the central “triskelion” of the Y. A structural comparison of the yeast CNC with an electron microscopy reconstruction of its human counterpart suggested the evolutionary conservation of the elucidated architecture. Moreover, 32 copies of the CNC crystal structure docked readily into a cryoelectron tomographic reconstruction of the fully-assembled human NPC, thereby accounting for ~16 MDa of its mass

Ozone-based eye drops activity on ocular epithelial cells and potential pathogens infecting the front of the eye

Confirmation of the biological effectiveness of new ophthalmic preparations introduced in the market is an important element in maintaining the safety of using this type of medications. This study aimed to investigate the activity of Ozodrop® on human corneal and conjunctival epithelial cells, as well as its antibacterial and antifungal activity. Cytotoxicity analyses of ocular surface epithelial cells were performed in vitro by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and Neutral Red uptake assays. The level of nitric oxide released by the cells was assessed by the Griess method. The reduction of the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical by the tested formulation was analyzed. Microbiological tests were also performed. It was found that the Ozodrop® preparation exhibited biological activity, but was less active than the reference antibiotics and the anti-yeast agent. The cytotoxic activity of the Ozodrop® formulation was dependent on the time of cell exposure to it. No toxic effect was observed in the short-term, for up to 3 h. It appeared after 24 h of exposure of the cells to the preparation. The drops showed antioxidant activity in the specified concentration range. They also stimulated the release of nitric oxide, mainly by corneal epithelial cells. The Ozodrop® formulation exhibits biological activity that can be considered useful in the treatment of infections in the front part of the eye

Optical emission spectroscopy of pulsed plasma streams emitted from a modified PF-1000 facility

The paper presents results of the recent spectroscopic studies of pulsed plasma streams generated in the PF-1000 facility at the IFPiLM in Warsaw. This facility has recently been equipped with a modified inner electrode, which had the front copperplate with a central tungsten (W) insert of 50 mm in diameter. Interactions of the collapsing current sheath and electron beams with this insert have changed characteristics of the X-ray and VR emission considerably. New spectroscopic measurements were performed at the chosen angle and perpendicular to the discharge axis. In the second case optical emission spectra were recorded at different distances from the electrode outlets, and at various instants after the current peculiarity (dip). It enabled to determine dynamics of the VR emission in the investigated VR range.Представлены результаты недавних спектроскопических исследований импульсных потоков плазмы, генерируемых установкой ПФ-1000, которая расположена в ИФПиЛМ в Варшаве. Эта установка недавно была оснащена модифицированным внутренним электродом, который имел переднюю медную пластину с центральной вольфрамовой (W) вставкой диаметром 5 мм. Взаимодействие схлопывающейся токовой оболочки и электронных пучков с этой вставкой значительно изменило характеристики рентгеновского и излучения в видимом диапазоне. Новые спектроскопические измерения проводились при выбранном угле и перпендикулярно к оси разряда. Во втором случае оптические спектры излучения были зарегистрированы на разных расстояниях от среза электродов и в различные моменты после токовой особенности осциллограммы тока (провала). Это позволило определить динамику ВИ в исследованном диапазоне.Представлені результати недавніх спектроскопічних досліджень імпульсних потоків плазми, що генеруються установкою ПФ-1000, яка розташована в ІФПіЛМ у Варшаві. Ця установка нещодавно була оснащена модифікованим внутрішнім електродом, який мав передню мідну пластину з центральною вольфрамовою (W) вставкою діаметром 50 мм. Взаємодія оболонки струму, яка схлопується, і електронних пучків з цією вставкою значно змінило характеристики рентгенівського випромінювання у видимому діапазоні. Нові спектроскопічні вимірювання проводилися при заданному куті та перпендикулярно до осі розряду. У другому випадку оптичні спектри випромінювання були зареєстровані на різних відстанях від зрізу електродів, і в різні моменти після особливості осцилограми струму (провалу). Це дозволило визначити динаміку ВВ у дослідженому діапазоні

Recent studies of the ion emission from high-current PF-1000 experiments

The paper describes diagnostics of fast ion beams emitted from a large PF-1000 facility operated at 21…27 kV, 290…480 kJ. Those beams were measured with pinhole cameras and PM-355 nuclear track detectors, placed at different angles to the discharge axis. The measurements showed a complex spatial structure of the fast ion beams. Measurements behind an axial channel in the inner electrode have shown that some ion beams are emitted also in the upstream direction. The ion energy spectra were measured with a miniature Thomson-type spectrometer. Time-resolved measurements of ions were performed with miniature scintillation detectors placed behind a pinhole

Recent studies of the ion emission from high-current PF-1000 experiments

The paper describes diagnostics of fast ion beams emitted from a large PF-1000 facility operated at 21…27 kV, 290…480 kJ. Those beams were measured with pinhole cameras and PM-355 nuclear track detectors, placed at different angles to the discharge axis. The measurements showed a complex spatial structure of the fast ion beams. Measurements behind an axial channel in the inner electrode have shown that some ion beams are emitted also in the upstream direction. The ion energy spectra were measured with a miniature Thomson-type spectrometer. Time-resolved measurements of ions were performed with miniature scintillation detectors placed behind a pinhole

Nitric Oxide (NO) and Cyclooxygenase-2 (COX-2) Cross-Talk in Co-Cultures of Tumor Spheroids with Normal Cells

Cyclooxygenases (COX), prostaglandin E2 (PGE2) and nitric oxide (NO) are believed to be some of the most important factors related to colon cancer growth and metastasis. In this study, we aimed to investigate the associations between COX-2, PGE2 and NO in co-cultures of human colon cancer spheroids obtained from different tumor grades with normal human colonic epithelium and myofibroblast monolayers. L-arginine (2 mM), a substrate for nitric oxide synthases (NOS), decreased COX-2 and PGE2 levels, while NG-nitro-L-arginine methyl ester (L-NAME) (2 mM), a NOS inhibitor, had no influence on COX-2 and PGE2 levels but limited tumor cell motility. NS398 (75 μM), a selective COX-2 inhibitor, had no significant influence on NO level but decreased motility of tumor cells. COX-2, PGE2 and NO levels depended on the tumor grade of the cells, being the highest in Duke’s stage III colon carcinoma. Summing up, we showed that addition of L-arginine at doses which did not stimulate NO level caused a significant decrease in COX-2 and PGE2 amounts in co-cultures of colon tumor spheroids with normal epithelial cells and myofibroblasts. Any imbalances in NO level caused by exogenous factors influence COX-2 and PGE2 amounts depending on the kind of cells, their reciprocal interactions and the local microenvironmental conditions. The knowledge of these effects may be useful in limiting colon carcinoma progression and invasion

Dense Plasma Focus: physics and applications (radiation material science, single-shot disclosure of hidden illegal objects, radiation biology and medicine, etc.)

The paper presents some outcomes obtained during the year of 2013 of the activity in the frame of the International Atomic Energy Agency Co-ordinated research project "Investigations of Materials under High Repetition and Intense Fusion-Relevant Pulses". The main results are related to the effects created at the interaction of powerful pulses of different types of radiation (soft and hard X-rays, hot plasma and fast ion streams, neutrons, etc. generated in Dense Plasma Focus (DPF) facilities) with various materials including those that are counted as perspective ones for their use in future thermonuclear reactors. Besides we discuss phenomena observed at the irradiation of biological test objects. We examine possible applications of nanosecond powerful pulses of neutrons to the aims of nuclear medicine and for disclosure of hidden illegal objects. Special attention is devoted to discussions of a possibility to create extremely large and enormously diminutive DPF devices and probabilities of their use in energetics, medicine and modern electronics