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1.
Space Sci Rev ; 219(5): 37, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37448777

RESUMO

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or ΔL∼0.56) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L∼5-7 at dusk, while a smaller subset exists at L∼8-12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L-shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

2.
Space Sci Rev ; 216(5): 103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32831412

RESUMO

The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (∼93∘ inclination), nearly circular, low-Earth (∼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (Torbit ∼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E < 40% and a fluxgate magnetometer (FGM) on a ∼72 cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5 Hz Nyquist (nominally) with <0.3 nT/sqrt(Hz) noise at 1 Hz. The spinning satellites (Tspin ∼ 3 s) are equipped with magnetorquers (air coils) that permit spin-up or -down and reorientation maneuvers. Using those, the spin axis is placed normal to the orbit plane (nominally), allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250 keV - 5 MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018 and launched by the ELaNa XVIII program on a Delta II rocket (with IceSatII as the primary). Mission operations are currently funded by NASA. Working under experienced UCLA mentors, with advice from The Aerospace Corporation and NASA personnel, more than 250 undergraduates have matured the ELFIN implementation strategy; developed the instruments, satellite, and ground systems and operate the two satellites. ELFIN's already high potential for cutting-edge science return is compounded by concurrent equatorial Heliophysics missions (THEMIS, Arase, Van Allen Probes, MMS) and ground stations. ELFIN's integrated data analysis approach, rapid dissemination strategies via the SPace Environment Data Analysis System (SPEDAS), and data coordination with the Heliophysics/Geospace System Observatory (H/GSO) optimize science yield, enabling the widest community benefits. Several storm-time events have already been captured and are presented herein to demonstrate ELFIN's data analysis methods and potential. These form the basis of on-going studies to resolve the primary mission science objective. Broad energy precipitation events, precipitation bands, and microbursts, clearly seen both at dawn and dusk, extend from tens of keV to >1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.

3.
J Geophys Res Space Phys ; 122(11): 10891-10909, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29399431

RESUMO

During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high-energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X-line was located relatively close to the Earth, approximately at 16-18 RE.

4.
Geophys Res Lett ; 43(10): 4841-4849, 2016 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-27867235

RESUMO

We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

5.
Vestn Khir Im I I Grek ; 175(3): 40-3, 2016.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-30444092

RESUMO

The analysis of treatment results of 128 patients aged from 21 to 62 years old with chronic posttraumatic osteomyelitis of the long bones was made at the period from 2006 to 2013. The main group included 67 patients and the method of programmed irrigation aspiration sanation was applied for them. The comparison group consisted of 61 patients and drainage was performed for these patients using the conventional ways. The authors noted good immediate results in the main group in 56 (83,58%) out of 67 patients and in the comparison group - in 43 (70,49%) out of 61 patients. The long-term results were analyzed in 116 (90,6%) out of 128 patients in terms from two to five years after treatment. The rate of recurrences such as formation of purulent fistula were twice less in patients of the main group, than in the comparison group. According to the results of questionnaire SF-36, there was noticed, that patients of the main group got better mean indices of quality of life on all 8 scales compared with the other group.


Assuntos
Anti-Infecciosos Locais/administração & dosagem , Drenagem , Fraturas Ósseas/complicações , Procedimentos Ortopédicos , Qualidade de Vida , Irrigação Terapêutica , Ossos da Extremidade Inferior/lesões , Ossos da Extremidade Superior/lesões , Desenho Assistido por Computador , Drenagem/efeitos adversos , Drenagem/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/métodos , Osteomielite/diagnóstico , Osteomielite/etiologia , Osteomielite/psicologia , Osteomielite/terapia , Irrigação Terapêutica/efeitos adversos , Irrigação Terapêutica/instrumentação , Irrigação Terapêutica/métodos , Resultado do Tratamento
6.
Angiol Sosud Khir ; 14(3): 125-7, 2008.
Artigo em Russo | MEDLINE | ID: mdl-19791441

RESUMO

The paper presents a case of successful heart chambers and coronary. Maging with gadolinium-based contrast agent Gadobutrol during CT-coronarography with 64-slice scanner in a patient with intolerance to iodinated contrast media. No adverse events were detected. In conclusion, Gadobutrol may be a safe and useful alternative contrast contraindications to iodinated material.


Assuntos
Angina Instável/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Compostos de Iodo , Compostos Organometálicos , Tomografia Computadorizada por Raios X/métodos , Idoso , Contraindicações , Diagnóstico Diferencial , Feminino , Gadolínio , Humanos , Injeções Intravenosas , Compostos Organometálicos/administração & dosagem
8.
Vopr Virusol ; 50(1): 42-6, 2005.
Artigo em Russo | MEDLINE | ID: mdl-15747873

RESUMO

Several cell cultures were compared and examined for their capability to support reproduction of Classical Swine Fever Virus (CSFV). Experimental conditions of virus cultivation were optimized. The subculture of primary lamb testicular (LT) cells was selected for large cell cultivation of CSFV. In contrast to many cell lines, these cells were free of Bovine Viral Diarrhea Virus (BVDV) contamination partly due to liquid nitrogen storage and gamma-ray sterilization of serum used in the growth media. The vaccine strain CS of CSFV was obtained in the titers of 6.7-7.7 TCID50/ml under the optimal conditions of virus reproduction in the LT cells.


Assuntos
Vírus da Febre Suína Clássica/crescimento & desenvolvimento , Animais , Células Cultivadas , Ovinos , Vacinas Atenuadas , Vacinas Virais , Cultura de Vírus
9.
Vopr Virusol ; 47(1): 39-44, 2002.
Artigo em Russo | MEDLINE | ID: mdl-11852783

RESUMO

An effective system for specific prevention of transmissive swine gastroenteritis (TSG) is based on the use of combined vaccine and combined vaccination. Combined vaccine is a lyophilized preparation for intranasal application and emulsion for intramuscular injection. The former is prepared from natural attenuated respiratory variant of TSG virus and the latter from artificially attenuated TSG virus. Combined vaccination consists in parallel double immunization of females on days 70-75 of gestation intramuscularly and intranasally and on days 90-95 of gestation intramuscularly. Vaccinal lactogenic immunity ensures protection of newborn piglets under experimental and field conditions (protection of 70-80 and 90-95% piglets, respectively). The proposed vaccine preparations and protocols of combined immunization of females during gestation by two methods are an effective and safe method for specific prevention of TSG.


Assuntos
Coronavirus/imunologia , Gastroenterite Suína Transmissível/prevenção & controle , Imunidade Materno-Adquirida , Vacinação/métodos , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia , Administração Intranasal , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/análise , Feminino , Gastroenterite Suína Transmissível/imunologia , Gastroenterite Suína Transmissível/transmissão , Esquemas de Imunização , Técnicas Imunoenzimáticas , Injeções Intramusculares , Leite/imunologia , Testes de Neutralização , Gravidez , Suínos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/uso terapêutico , Vacinas Virais/uso terapêutico
10.
Zh Vopr Neirokhir Im N N Burdenko ; (1): 10-2; discussion 12-3, 2000.
Artigo em Russo | MEDLINE | ID: mdl-10738757

RESUMO

Examination and treatment policy is proposed for patients with complicated vertebral injury under the conditions of urgent neurosurgical service. Its practical use at Saint Petersburg city multidisciplinary hospital No. 26 in 207 patients with vertebral and spinal cord injury substantially improved the outcomes of this severe group of patients. A wide range of surgical interventions into the vertebral column was used. Treatment yielded fair and good results in 188 (85.9%) patients.


Assuntos
Procedimentos Neurocirúrgicos/métodos , Ortopedia/métodos , Traumatismos da Medula Espinal/cirurgia , Traumatismos da Coluna Vertebral/cirurgia , Doença Aguda , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Coluna Vertebral/diagnóstico
11.
Voen Med Zh ; 321(1): 27-30, 112, 2000 Jan.
Artigo em Russo | MEDLINE | ID: mdl-10701347

RESUMO

10-year experience in prosthetics of extremity stumps in conditions of the Central Military Clinical Hospital N 6 was analyzed. In the hospital during the period from 1989 to 1999 prosthetic appliance was made in 203 patients with amputating defects of extremities, 37 of them with pair stumps and 1 with lack of segments of all extremities. Most patients (80.5%) had stumps at the level of femur and crus. Basing on the analysis of modern scientific literature and experience gained in hospital the authors have formulated organizational and methodical states. Thanks to observance of the stated principles it was possible to optimize considerably the process of medico-psychological and social rehabilitation, to achieve good functional results in all patients treated in the hospital. Adequate use of experience in other military medical and prophylactic institutions will contribute to significant decrease in periods of return of servicemen to social useful labour and increase in efficiency of rehabilitation measures.


Assuntos
Amputação Traumática/reabilitação , Traumatismos do Braço/reabilitação , Traumatismos da Perna/reabilitação , Militares , Amputação Traumática/psicologia , Braço , Traumatismos do Braço/psicologia , Membros Artificiais , Humanos , Perna (Membro) , Traumatismos da Perna/psicologia , Militares/psicologia , Reabilitação/métodos , Reabilitação/organização & administração , Reabilitação/psicologia , Federação Russa , Ajustamento Social
12.
Mol Gen Mikrobiol Virusol ; (2): 34-40, 1999.
Artigo em Russo | MEDLINE | ID: mdl-10396731

RESUMO

Primary structure of a genome fragment of attenuated strain CS of hog cholera virus (HCV) coding for three surface glycoproteins Erns, E1, and E2 (fragment size 2379 nucleotides) is analyzed. By the nucleotide sequence the homology between strain CS and ten other virulent and attenuated HCV strains in this area is 84.9-94.6%, 87.2-94.6% in gene Erns, 84.6-96.9% in gene E1, and 83.3-94.3% in gene E2. By amino acid sequence the homology is 90.9-94.3%, 92.9-95.0%, 92.3-95.6%, and 88.9-94.1%, respectively. Computer analysis demonstrated philogenetic ratios between these strains and other HCV strains and the areas of potential antigenic differences between CS strain and other HCV strains. The data indicate that strain CS used as live vaccine protecting from HCV contains unique nucleotide and amino acid positions and its evolution history is different from that of analyzed reference strains. The data will be further used for detecting the fine antigenic structure of strain CS surface glycoproteins with the aim of disclosing unique antigenic markers.


Assuntos
Vírus da Febre Suína Clássica/genética , Glicoproteínas de Membrana/genética , Proteínas do Envelope Viral/genética , Vacinas Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Primers do DNA , Glicoproteínas de Membrana/química , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Proteínas do Envelope Viral/química
14.
Vopr Virusol ; 39(5): 212-4, 1994.
Artigo em Russo | MEDLINE | ID: mdl-7716904

RESUMO

Three modifications of quantitative enzyme immunoassay (EIA) for assessment of Aujeszky's disease virus (ADV) in culture medium are compared, in which monoclonal antibodies (MAB) to ADV GH glycoprotein were used: nonconcurrent two-site "sandwich" EIA on the basis of two different MABs, indirect concurrent EIA, and direct concurrent EIA. MABs fit best of all for use in every of EIA modifications were selected. Conditions of the assays were optimized. Concurrent EIAs were 10-20 times less sensitive than sandwich EIA. The developed sandwich EIA permitted ADV assay in preparations of both live and formaldehyde-inactivated virus.


Assuntos
Anticorpos Monoclonais , Pseudorraiva/diagnóstico , Animais , Chlorocebus aethiops , Meios de Cultura , Herpesvirus Suídeo 1/imunologia , Técnicas Imunoenzimáticas , Células Vero
15.
Vopr Virusol ; 39(4): 174-7, 1994.
Artigo em Russo | MEDLINE | ID: mdl-7527989

RESUMO

A panel of 24 different monoclonal antibodies (MAB) to Aujeszky's disease virus (ADV) proteins was prepared. Seven MABs were directed to ADV glycoprotein GII (6 MABs to GIIc chain and 1 MAB to GIIb chain). GII epitope mapping with the resultant MABs was carried out. Four ADV GII epitopes were detected: epitopes A, B, and C located on GIIc chain and epitope D located on GIIb chain. Epitope B overlaps epitopes A and C which do not overlap each other, epitope D does not overlap other epitopes. Epitopes A, B, and C are located in a restricted area of GIIc chain which seems to be one of GII immunodominant regions. The detected epitopes are mainly conformational, for they are sensitive to denaturation. Of all MABs obtained more than 30% were directed to ADV GII. This indicates that GII is one of the most important ADV antigens. All the seven MABs to GII interacted with all tested ADV strains (K. Arsky, VGNKI, BUK, and NIA-4), this being in line with the data on a highly conservative nature of ADV GII.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Mapeamento de Epitopos/métodos , Glicoproteínas/imunologia , Herpesvirus Suídeo 1/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Antígenos Virais/análise , Eletroforese em Gel de Poliacrilamida , Mapeamento de Epitopos/instrumentação , Epitopos/análise , Glicoproteínas/isolamento & purificação , Hibridomas/imunologia , Imunização/métodos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Envelope Viral/isolamento & purificação
17.
Patol Fiziol Eksp Ter ; (2): 44-6, 1992.
Artigo em Russo | MEDLINE | ID: mdl-1408394

RESUMO

The authors studied changes of electrical activity of the gastroduodenal smooth muscles, sympathetic efferent impulses in the postganglionic branches of the celiac plexus and macro-morphology of the gastric mucosa during the development of indomethacin gastropathies. By the end of the 3rd hour and later after the injection of the drug (15, 30 mg/kg) progressive inhibition of impulses and basal rhythm of gastric smooth muscles was encountered in intensified electrical activity of the duodenal smooth muscles, as well as destructions in the gastric mucosa even to the development of ulcers (6-24 hours). It is concluded that the development of indomethacin hemorrhages and ulcerations along with other factors is caused by excitation of the sympathetic nervous system attended by phasic changes of the sympathetic efferent impulses and electrical activity of the gastroduodenal zone.


Assuntos
Hemorragia Gastrointestinal/fisiopatologia , Indometacina/toxicidade , Úlcera Gástrica/fisiopatologia , Sistema Nervoso Simpático/fisiologia , Animais , Hemorragia Gastrointestinal/induzido quimicamente , Masculino , Ratos , Úlcera Gástrica/induzido quimicamente
18.
Farmakol Toksikol ; 54(3): 37-9, 1991.
Artigo em Russo | MEDLINE | ID: mdl-1915818

RESUMO

Serotonin, histamine, tryptophan administered in low doses were shown to protect the rat gastric mucosa against indomethacin-induced hemorrhages. When administered in high doses, serotonin retained the protective properties, while histamine and histidine, on the contrary, increased the hemorrhagic lesion of the tissue. Tryptophan and histidine given in low doses promoted a decrease of the indomethacin elevated levels of serotonin and histamine in the gastric mucosa.


Assuntos
Aminoácidos/uso terapêutico , Monoaminas Biogênicas/uso terapêutico , Indometacina/toxicidade , Úlcera Gástrica/tratamento farmacológico , Animais , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Masculino , Úlcera Péptica Hemorrágica/induzido quimicamente , Úlcera Péptica Hemorrágica/tratamento farmacológico , Ratos , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/complicações
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