Effect of the applied magnetic field on formation of complex polyaniline films

Formation of complex polyaniline (PANI) films with diamagnetic TCNQ and paramagnetic metal ion impurities cast under applied magnetic field was studied. It has been found that the applied magnetic field affects interaction of PANI chains with the impurities and induces formation of magnetically ordered regions in the complex film doped by paramagnetic metal ions in contrast to the reference film of the same composition but prepared under ambient conditions. The magnetically ordered regions have been observed directly by scanning magnetic force microscopy. It was found a correlation in distribution of the magnetically ordered regions and peculiarities of the surface relief of a film. Electronic absorption spectra and conductivity measurements showed that an applied stationary magnetic field can suppress the interaction of PANI chains and paramagnetic metal ions and lowers conductivity of the resulting complex film up to one order of magnitude as compared with the reference film. An alternating magnetic field was found to improve interaction of PANI and diamagnetic TCNQ molecules. The mechanisms of the magnetic field influence on the complex film formation are discussed.Comment: 15 pages, 10 figure

Ferromagnetism in Co-doped ZnO films grown by molecular beam epitaxy: magnetic, electrical and microstructural studies

We studied structural, optical and magnetic properties of high-quality 5 and 15% Co-doped ZnO films grown by plasma-assisted molecular beam epitaxy (MBE) on (0001)-sapphire substrates. Magnetic force microscopy (MFM) and magnetic measurements with SQUID magnetometer show clear ferromagnetic behavior of the films up to room temperature whereas they are antiferromagnetic below 200 K approximately. Temperature dependence of the carrier mobility was determined using Raman line shape analysis of the longitudinal-optical-phonon-plasmon coupled modes. It shows that the microscopic mechanism for ferromagnetic ordering is coupling mediated by free electrons between spins of Co atoms. These results bring insight into a subtle interplay between charge carriers and magnetism in MBE-grown Zn(1-x)CoxO films.Comment: 10 pages, 9 figures, 2 table

Surgical treatment of combined biliary and vascular injury following cholecystectomy

Institutul Naţional de Chirurgie şi Transplantologie “A.Shalimov”, Kiev, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Leziunile combinate ale vaselor şi căilor biliare extrahepatice reprezintă una dintre cele mai serioase complicaţii după colecistectomie. Efectuarea rezecţiei sau transplantului hepatic a fost necesară la 13,2-57,0% dintre pacienţii cu leziuni bilio-vasculare combinate (LBV).Materiale şi metode: Au fost incluşi 31 pacienţi cu LBV după colecistectomie în perioada ianuarie 1984 - ianuarie 2015. La 21 (67,7%) pacienţi leziunile au apărut după colecistectomia deschisă, la 10 (32,3%) – după cea laparoscopică. Intraoperator au fost înregistrate 6 (19,4%) leziuni ale ducturilor biliare. În perioada postoperatorie precoce (pînă la 7 zile) prezenţa unei stenoze de ramură a arterei hepatice este stabilită la 4 (12,9%) pacienţi, în perioada tardivă (8 zile – 3 ani) – la 21 (67,7%). În 5 (16,1%) cazuri a fost înregistrată stenoza arterei hepatice comune, în 24 (77,4%) – a ramurii drepte şi în 2 (6,5%) – a ramurii stîngi. Rezultate: La 2 pacienţi s-au efectuat tentative de restabilire a stenozei arteriale. Datorită dezvoltării colateralelor arterei hepatice comune 19 pacienţi au reluat fluxul hepatic arterial şi au suportat numai hepaticojejunoanastomoză. În 2 cazuri preventiv s-a efectuat embolizarea anevrismului arterei hepatice. Rezecţia de ficat s-a efectuat la 9 (29,0%) pacienţi. La 16 pacienţi cu LBV s-a dezvoltat necroza ficatului cu abcese. Concluzii: Rezultate pozitive în termen de 10 ani sunt înregistrate la 27 (86,2%) bolnavi, rezultate nesatisfăcătoare – la 4 (13,8%), un pacient a decedat. Astfel, pacienţii cu LBV combinate necesită tratament multimodal ţinînd cont de caracteristicile clinice actuale.Introduction: The combined damage of extra hepatic biliary ducts and vessels are the most serious complication of a cholecystectomy. Performance of the resection or liver transplantation was required 13.2-57.0% of patients with the combined biliovascular injury (BVI). Methods: 31 patients with the BVI after cholecystectomy, from January 1984 till January 2015. In 21 (67.7%) patients damage occured during open cholecystectomy, at 10 (32.3%) – laparoscopic. Intraoperatively injury of biliary duct is diagnosed in 6 (19.4%) cases. In the early postoperative period (to 7 days) existence of an occlusion of branches of the hepatic artery is established in 4 (12.9%) patients, in late (8 days-3 years) – in 21 (67.7%). In 5 (16.1%) cases the occlusion of the common hepatic artery, 24 (77.4%) – right brunch and 2 (6.5%) – left brunch was found. Results: Two patients had attempts of restoration of an arterial blood groove. Owing to hepatic artery collaterals development 19 patients resumed hepatic artery flow and underwent hepaticojejunostomy as a result only. In two cases it was preceded by embolization of hepatic artery aneurism. Liver resection is performed in 9 (29.0%) patients. At 16 patients with the BVI developed liver necrosis with abscesses. Conclusion: Positive results in terms to 10 years are received at 27 (86.2%), unsatisfactory – 4 (13.8%), one patient died. Thus, patients with the combined BVI need multimodal tactic of treatment taking into account features of their clinical current

Micropatterning in bistable cholesteric device with Bragg’s reflection

In this work, the method to form bistable patterning in a cholesteric cell with Bragg’s reflection in the visible spectral range is demonstratedyesBelgorod State Universit

Correlation between Crystallographic Alignment of Self-induced GaN Nanowires and Features of Si(111) Nitridation

Formation and spatial ordering of self-induced GaN nanowires grown by molecular beam epitaxy on a spatially pre-nitridazed Si(111) substrate have been studied. It was found the close correlation between Si substrate nitridation parameters and crystallographic alignment of NWs. Conditions for NWs nucleation and in- plane orientation are predefined by a structural anisotropy of silicon nitride nanolayer. Mechanism of NWs orderly emergence suggested. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

RF PLASMA EFFECT ON AMORPHOUS THIN ION-IMPLANTED LAYERS OF N- AND P-TYPE GERMANIUM: RAMAN AND AFM RESEARCH

Effect of RF plasma treatment (RFPT) and rapid thermal annealing (RTA) on high-dose implanted n-type and p-type amorphous Ge layers has been studied by Raman scattering spectroscopy and AFM techniques. To recrystallize the amorph-ous thin n-Ge layer implanted by BF2+ ions needed higher RTA temperatures and power density of RFPA than in the case of p-Ge implanted by P+ ions with a same dose. It was shown that the RFPT resulted in recrystallization of amorphous Ge layers at considerably lower temperatures than RTA, that it was associated with nonthermal effects. Low-energy ion and electron bom-bardment during RFPT resulted in formation of nanostructured Ge surface

Regulated expression of human beta-defensin-2 leads to altered phenotype and growth patterns of cultured human embryonal kidney cells

Aim: To create cell line with regulated expression of human beta-defensin-2 (hBD-2) and evaluate the influence of expressed peptide on its phenotypic and growth patterns. Materials and Methods: Using cloning techniques, on the base of human embryonic kidney cells of HEK293T line, stable T-rex HEK-hBD2-m cell subline expressing mature biologically active hBD-2 molecule upon the presence of tetracycline in culture medium was generated. The morphological patterns, growth characteristics and colony forming activity of these cells were studied using routine techniques. Results: T-rex HEK-HBD2-m cell subline was shown to express both mRNA and hBD-2m protein upon the presence of 1 µg/ml tetracycline in culture medium as it was demonstrated by RT-PCR and immunocytochemical approach. Upon prolonged expression of hBD-2, the cells acquired special features: they lost ability to grow in monolayer in vitro and to form colonies in soft agar, characteristic to parental HEK293T cells, but possess higher growth rate and longer survival in FBS-free medium than wild type cells. Conclusion: Expression of hBD-2 in T-rex HEK-HBD2-m cell subline results in specific biological consequences that favor cell survival.Цель: создать линию клеток с регулируемой экспрессией бета-дефенсина-2 человека (hBD-2) и проанализировать влияние экспрессии этого пептида на особенности фенотипа и рост клеток. Материалы и методы: клеточная сублиния T-rex HEK hBD2-m, экспрессирующая биологически активную зрелую форму hBD-2 при индукции клеток тетрациклином, получена путем клонирования на основе эмбриональных клеток почки человека линии HEK293T. Морфологические особенности, характеристики роста и показатели колониеобразования в полужидкой среде исследовали стандартными методами. Результаты: с помощью методов РТ-ПЦР и иммуноцитохимии показано, что сублиния клеток T-rex HEK-HBD2- экспрессирует hBD2 в присутствии 1 µг/мл тетрациклина в среде инкубации. Продолжительная экспрессия hBD-2 приводила к тому, что клетки утрачивали способность образовывать монослой при культивировании in vitro и образовывать колонии в полужидкой среде, но характеризовались более высокой скоростью роста и способностью к более продолжительному выживанию в бессывороточной среде, чем исходная линия клеток HEK293T. Выводы: экспрессия hBD-2 в сублинии клеток T-rex HEK-HBD2- cell обусловливает специфические биологические эфеекты, способствующие выживанию клеток