Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Nanotechnology ; 27(11): 115304, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-26878568

RESUMO

Electron-beam-induced deposition of titanium oxide nanopatterns is described. The precursor is titanium tetra-isopropoxide, delivered to the deposition point through a needle and mixed with oxygen at the same point via a flow through a separate needle. The depositions are free of residual carbon and have an EDX determined stoichiometry of TiO2.2. High resolution transmission electron microscopy and Raman spectroscopy studies reveal an amorphous structure of the fabricated titanium oxide. Ellipsometric characterization of the deposited material reveals a refractive index of 2.2-2.4 RIU in the spectral range of 500-1700 nm and a very low extinction coefficient (lower than 10(-6) in the range of 400-1700 nm), which is consistent with high quality titanium oxide. The electrical resistivity of the titanium oxide patterned with this new process is in the range of 10-40 GΩ cm and the measured breakdown field is in the range of 10-70 V µm(-1). The fabricated nanopatterns are important for a variety of applications, including field-effect transistors, memory devices, MEMS, waveguide structures, bio- and chemical sensors.

2.
Nanotechnology ; 25(15): 155301, 2014 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-24642787

RESUMO

An oxygen-assisted electron-beam-induced deposition (EBID) process, in which an oxygen flow and the vapor phase of the precursor, tetraethyl orthosilicate (TEOS), are both mixed and delivered through a single needle, is described. The optical properties of the SiO(2+δ) (- 0.04 ≤ δ ≤ +0.28) are comparable to fused silica. The electrical resistivity of both single-needle and double-needle SiO(2+δ) are comparable (greater than 7 GΩ cm) and a measured breakdown field is greater than 400 V µm(-1). Compared to the double-needle process the advantage of the single-needle technique is the ease of alignment and the proximity to the deposition location, which facilitates fabrication of complex 3D structures for nanophotonics, photovoltaics, micro- and nano-electronics applications.

3.
Phys Rev Lett ; 110(1): 017601, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23383836

RESUMO

We report ferromagnetic resonance force microscopy of confined spin-wave modes with improved, 100 nm resolution. The ferromagnetic resonance spectra in Permalloy disks (diameters ranging from 100 to 750 nm) distinguish multiple edge modes, and the images reveal distinct precession patterns. The fundamental edge mode also provides a new, localized probe of the magnetic properties of the film edge; rotation of the applied field reveals large edge property variations in nominally circular disks. As a function of disk diameter, the number of observed edge modes agrees with modeling.

4.
Rev Sci Instrum ; 83(9): 093711, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23020387

RESUMO

Magnetic force microscope Co spike tips with lateral magnetic resolution of 10 nm have been prepared. The Co spikes are grown by electron beam induced deposition of Co from Co(2)(CO)(8) gas precursor. The high resolution Co spikes are fabricated at the spot of a tightly focused electron beam on the tip of commercial atomic force microscope cantilevers. Qualitative investigations indicate that a spike grown on a planar base of Co improves the signal to noise.

5.
Phys Rev Lett ; 108(8): 087206, 2012 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-22463567

RESUMO

We use the dipolar fields from a magnetic cantilever tip to generate localized spin wave precession modes in an in-plane magnetized, thin ferromagnetic film. Multiple resonances from a series of localized modes are detected by ferromagnetic resonance force microscopy and reproduced by micromagnetic models that also reveal highly anisotropic mode profiles. Modeled scans of line defects using the lowest-frequency mode provide resolution predictions of (94.5±1.5) nm in the field direction, and (390±2) nm perpendicular to the field.

6.
Nanotechnology ; 22(14): 145305, 2011 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21368354

RESUMO

A new method of direct, rapid nano- to micro-scale patterning of high purity cobalt is presented. The method utilizes a combination of electron beam induced deposition (EBID) and seeded growth at elevated temperatures below the temperature of spontaneous thermal decomposition. Dicobalt octacarbonyl Co2(CO)8 is used as the precursor and carbon as a seed layer. Seeded deposition is carried out in the substrate temperature range from 55 to 75 °C. Deposition yield is significantly higher than conventional EBID and magnetotransport measurements indicate that resistivity, 22 µΩ cm, and saturation magnetization, 1.55 T, are much closer to the corresponding values for bulk Co than those for standard EBID.

7.
Nanotechnology ; 22(5): 055302, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21178259

RESUMO

Thermally assisted electron beam induced deposition can result in an improvement of the purity of nano-scale depositions. Six commonly used organic precursors were examined: W(CO)(6), TEOS (tetraethylorthosilicate), MeCpPtMe(3), Co(CO)(3)NO, Co(2)(CO)(8), and Me(2)Auacac. The last two precursors were also tested on two different instruments to confirm reproducibility of the results. The influence of the substrate temperature on the composition of the deposition has been quantified systematically in the temperature range 25-360 °C. It has been shown that most purities improve when applying an elevated temperature, while the shape of the deposition remains intact. The purity improvement is achieved at the cost of a lower deposition yield. The amount of improvement is different for each precursor. Within the maximum temperature range of 360 °C, the best improvement was found for W(CO)(6): from 36.7 at.% at 25 °C to 59.2 at.% at 280 °C. For both cobalt precursors an additional transition region between patterned electron beam induced deposition (EBID) and thermal thin film growth has been identified. In this region seeded growth occurs with strongly increased growth rates.

8.
Parazitologiia ; 44(2): 191-3, 2010.
Artigo em Russo | MEDLINE | ID: mdl-20536012

RESUMO

Two species of Coccidia, Eimeria truttae (Leger et Hesse, 1919) and Eimeria lydiae (Lukes et Kepr, 1992), have been found for the first time in the trout Salmo trutta from the rivers of Kaliningrad Region, Russia.


Assuntos
Eimeriidae/classificação , Eimeriidae/isolamento & purificação , Salmonidae/parasitologia , Animais , Intestinos/parasitologia , Rios/parasitologia , Federação Russa
9.
Parazitologiia ; 42(3): 169-78, 2008.
Artigo em Russo | MEDLINE | ID: mdl-18727361

RESUMO

Data on the Coccidia parasitizing fishes of 12 orders (Acipenseriformes, Clupeiformes, Salmoniformes, Anguilliformes, Siluriformes, Atheriniformes, Gadiformes, Gasterosteiformes, Syngnatiformes, Mugiliformes, Scorpaeniformes, and Pleuronectiformes) are given. Authors and year of description, synonymy, morphofunctional organization of exogenic stages, and list of hosts are presented for each coccidian species.


Assuntos
Coccidiose/veterinária , Eimeriida/citologia , Eimeriida/fisiologia , Doenças dos Peixes/parasitologia , Animais , Coccidiose/parasitologia , Eimeriida/classificação , Peixes/parasitologia , Água Doce/parasitologia , Federação Russa
10.
Parazitologiia ; 40(5): 447-61, 2006.
Artigo em Russo | MEDLINE | ID: mdl-17144405

RESUMO

Thorough data on 67 coccidian species of the genera Eimeria, Goussia, and Isospora parasitizing fishes in the continental waters of Russia are given. Authors, year of description, synonyms, morphofunctional organization, and list of the hosts are reported for each species. The paper is supplied with figures of the exogenic stages of coccidia (oocysts).


Assuntos
Cipriniformes/parasitologia , Eimeria/citologia , Doenças dos Peixes/parasitologia , Água Doce/parasitologia , Isospora/citologia , Animais , Eimeria/classificação , Isospora/classificação , Federação Russa
11.
Parazitologiia ; 40(6): 527-34, 2006.
Artigo em Russo | MEDLINE | ID: mdl-17285756

RESUMO

Twenty one coccidian species from the genera Eimeria and Goussia are found in the perciform fish hosts from the continental waters of Russia. Names, authors and dates of the species descriptions, synonyms, brief figured description of the morphofunctional organization of the endogenic developmental stages of coccidian, Latin and Russian names of the fish hosts are given.


Assuntos
Coccidiose/veterinária , Eimeriidae/isolamento & purificação , Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Animais , Coccidiose/parasitologia , Eimeriidae/classificação , Eimeriidae/fisiologia , Água Doce , Oocistos
12.
Parazitologiia ; 38(6): 524-34, 2004.
Artigo em Russo | MEDLINE | ID: mdl-15656095

RESUMO

Similar strategies to preserve a species were evolved independently in different groups of Coccidea. Polyenergid oocysts and tissue cysts are found in representatives of the orders Protococcidiida and Eimeriida. Hypnozoits are found in Karyolysus lacerate and Plasmodium vivax; transovarial transmission of parasites occurs in life cycles of Coccidea of the genera Karyolysis and Babesia. Formation of heteroxenity in groups of Coccidea apparently was developed by different ways and in different periods. In some groups (Cystoisospora, Toxoplasma, Aggregata, Atoxoplasma, Schelackia, Lankesterella, and Calyptospora), recent definitive hosts were initial hosts; in other groups (Sarcocystis, Karyolysus, Haemogregarina, Hepatozoon, Plasmodium, Haemoproteus, Leucytozoon, Babesiosoma, Theileria, and Babesia), intermediate hosts were initial hosts.


Assuntos
Evolução Biológica , Coccídios/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Animais , Especificidade da Espécie
13.
Parazitologiia ; 37(4): 324-32, 2003.
Artigo em Russo | MEDLINE | ID: mdl-14515510

RESUMO

The isosporan-type of oocysts is a later evolutionary purchase in comparison with the eimerioran-type construction of oocysts'. Identical number of sporocysts and sporozoits in the oocysts, bivalvular constructions of sporocysts, heteroxenous life cycles and endogenous sporulation in a group series of coccidia have arisen asynchronously and independently. The evolution of RNA genes and a type of oocysts construction was proceeded in different species of the isosporan-type coccidia and with different velocities.


Assuntos
Evolução Biológica , Coccídios/fisiologia , Oocistos/crescimento & desenvolvimento , Animais , Coccídios/citologia , Coccídios/genética , Oocistos/citologia , Filogenia , RNA de Protozoário/genética
14.
Parazitologiia ; 37(2): 162-5, 2003.
Artigo em Russo | MEDLINE | ID: mdl-12815820

RESUMO

A new coccidia species Eimeria stizostedioni from the pikeperch Stizostedion lucioperca (Perciformes) is described. Localities: Neva river. Prevalence: 20% (1/5). Intensity of infection weak. Oocysts 7.5-8.0 x 10.0-12.5 microns. The form varies from oval up to ovoid; a wall is sleek, colourless, single-layer two-planimetric, micropyle, the polar granules and residual body are absent. Sporocysts 3.5 x 6.5 microns, with Stieda body and residual body represented by few small granules. Sporogony is endogenous.


Assuntos
Eimeria/classificação , Perciformes/parasitologia , Animais , Coccidiose/epidemiologia , Coccidiose/parasitologia , Eimeria/citologia , Eimeria/isolamento & purificação , Fezes/parasitologia , Água Doce/parasitologia , Prevalência , Federação Russa/epidemiologia
15.
Parazitologiia ; 37(6): 517-26, 2003.
Artigo em Russo | MEDLINE | ID: mdl-14964853

RESUMO

Approximately 3660 species of Coccidea belonging to 73 genera and 29 families parasitize representatives of the Metazoa kingdom. Coccidea were discovered in 10 of 35 phyla of Metazoa; in the most cases a direct correlation between the number of species in a host group and the number of Coccidea known from that group is clearly traced. Host groups, which are most archaic phylogenetically, are also parasitized by the archaic Coccidea groups. Evolutionarily derived hosts are parasitized by groups of Coccidea, which are the youngest phylogenetically. Parallel development of Coccidea and their hosts may be used for an indirect determination the time of origin of different Coccidea groups.


Assuntos
Coccídios , Invertebrados/parasitologia , Animais , Biodiversidade , Especificidade da Espécie
16.
Parazitologiia ; 35(3): 221-7, 2001.
Artigo em Russo | MEDLINE | ID: mdl-11558339

RESUMO

Description of coccidian species infecting freshwater fishes is given. Localities: Neman river, Goussia peleci sp. n.--oocyst 37.5-45 x 35-42.5 microns, oocyst residuum (OR) absent, sporocysts 20-22.5 x 15-17.5 microns, Stieda body (SB) absent, sporocyst residuum (SR) present, host (h)--Pelecus cultratus; G. cultrati sp. n.--oocyst 22.5-30 microns, OR absent, sporocysts 12.5 x 15 microns, SR, SB absent, wall 2-2.5 microns, h--P. cultratus; G. arinae sp. n.--oocyst 12.5 x 17.5 microns, OR present, sporocysts 5-7.5 microns, SR, SB absent, h--P. cultratus; G. vimbae sp. n.--oocyst 15-22.5 microns, OR absent, wall 2.5 microns, sporocysts 5-7.5 microns, SR, SB absent, h--Vimba vimba vimba; G. gymnocephali sp. n.--oocyst 25 x 25 microns, OR absent, sporocysts 10 x 12.5 microns, SR, SB absent, h--Gymnocephalus cernuus; G. cernui sp. n.--oocyst 15-22.5 microns, OR present, sporocysts 5-12.5 microns, SR, SB absent, h--Gym. cernuus; G. luciopercae sp. n.--oocyst 30-35 x 30 microns, OR absent, sporocysts 12.5-15 x 10-12.5 microns, SB absent, SR present, h--Stizostedion lucioperca; Eimeria fluviatili sp. n.--oocyst 20-22.5 microns, OR present, sporocysts 7.5 x 12.5 microns, SB present, SR absent, h--Perca fluviatilis.


Assuntos
Coccídios/classificação , Coccídios/isolamento & purificação , Peixes/parasitologia , Animais , Água Doce/parasitologia , Federação Russa
17.
Parazitologiia ; 34(6): 522-33, 2000.
Artigo em Russo | MEDLINE | ID: mdl-11212619

RESUMO

There are about 250 coccidian species associated with fishes. They belong to 8 genera (Calyptospora, Cryptosporidium, Crystallospora, Eimeria, Epieimeria, Goussia, Isospora, Octosporella) and 3 families (Calyptosporidae, Cryptosporidiidae, Eimeriidae). Two genera are represented by great number of species associated with fishes: Eimeria--157 and Goussia--69 species. Most diverse fauna of coccidians was found in fishes of the class Actinopterigii; fishes of the class Elasmobranchii have significantly less number of coccidians. These parasites have never been recorded on the class Holocephali. Coccidian have been recorded in 55 orders of fishes. Within the Actinopterigii, the richest coccidian fauna is recorded from Cypriniformes and Perciformes. Accumulated data on host associations proves that coccidian species have mainly a restricted hosts specificity.


Assuntos
Apicomplexa , Peixes/parasitologia , Animais , Apicomplexa/classificação , Peixes/classificação
19.
Parazitologiia ; 32(3): 268-76, 1998.
Artigo em Russo | MEDLINE | ID: mdl-9702803

RESUMO

After the carried out examination of different animals belonging to four phyla, Annelida, Mollusca, Arthropoda, and Chordata, the blastocysts were detected within three phyla, Annelida, Arthropoda, and Chordata. Within the phylum Annelida the blastocysts were found in Hirudinea, within the phylum Arthropoda--in Insecta, within the phylum Chordata--in Amphibia, Reptilia, Aves, and Mammalia.


Assuntos
Blastocystis/patogenicidade , Anfíbios/parasitologia , Animais , Aves/parasitologia , Peixes/parasitologia , Interações Hospedeiro-Parasita , Invertebrados/parasitologia , Mamíferos/parasitologia , Répteis/parasitologia , Especificidade da Espécie
20.
Parazitologiia ; 32(6): 553-9, 1998.
Artigo em Russo | MEDLINE | ID: mdl-10188173

RESUMO

The ultrastructure stages of Blastocystis galli were studied in chicken's intestine and in laboratory cultures. There were found morphological structures: surface coat (cell from chickens' intestine showed a very thick surface coat); cell membrane--there were some small electron-opaque deepening "pockets" on the membrane; inner membrane; endoplasmic reticulum with attached ribosomes, which present in the cytoplasm; all cells contained numerous of small vacuoles and large glycogen inclusions in cytoplasm; mitochondria with tubular cristae; nucleus with granules condensed chromatin; central vacuole; Golgi complex was represented by number of plates grouped in a pite; the cyst-like forms were surrounded by multilayered wall.


Assuntos
Blastocystis/ultraestrutura , Galinhas/parasitologia , Animais , Blastocystis/isolamento & purificação , Infecções por Blastocystis/parasitologia , Infecções por Blastocystis/veterinária , Intestino Grosso/parasitologia , Microscopia Eletrônica , Doenças das Aves Domésticas/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA