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1.
Science ; 291(5502): 280-2, 2001 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-11209072

RESUMO

Conductivity measurements on double-stranded DNA molecules deposited by a combing process across a submicron slit between rhenium/carbon metallic contacts reveal conduction to be ohmic between room temperature and 1 kelvin. The resistance per molecule is less than 100 kilohm and varies weakly with temperature. Below the superconducting transition temperature (1 kelvin) of the contacts, proximity-induced superconductivity is observed. These results imply that DNA molecules can be conducting down to millikelvin temperature and that phase coherence is maintained over several hundred nanometers.


Assuntos
DNA/química , Condutividade Elétrica , Impedância Elétrica , Eletroquímica , Eletrodos , Microscopia de Força Atômica , Temperatura
2.
Nat Commun ; 8: 15941, 2017 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-28677681

RESUMO

The protection against backscattering provided by topology is a striking property. In two-dimensional insulators, a consequence of this topological protection is the ballistic nature of the one-dimensional helical edge states. One demonstration of ballisticity is the quantized Hall conductance. Here we provide another demonstration of ballistic transport, in the way the edge states carry a supercurrent. The system we have investigated is a micrometre-long monocrystalline bismuth nanowire with topological surfaces, that we connect to two superconducting electrodes. We have measured the relation between the Josephson current flowing through the nanowire and the superconducting phase difference at its ends, the current-phase relation. The sharp sawtooth-shaped phase-modulated current-phase relation we find demonstrates that transport occurs selectively along two ballistic edges of the nanowire. In addition, we show that a magnetic field induces 0-π transitions and ϕ0-junction behaviour, providing a way to manipulate the phase of the supercurrent-carrying edge states and generate spin supercurrents.

3.
Ter Arkh ; 60(3): 87-9, 1988.
Artigo em Russo | MEDLINE | ID: mdl-3388281

RESUMO

The content of sputum trace elements was investigated in 12 patients with bronchial asthma (BA). The presence of Na, K, Ca, P, Mg, Si, Sn, Fe, Mn, Cu, Ti, Ag, Al, V, B was revealed. The absence of Zn and high levels of Ca and Sn were observed. Multiple crystalline Ca precipitates (phosphates, carbonates and oxalates) were found in the sputum of 56 BA patients. Ammonium urate and uric acid were also revealed. The author supposed disturbance of calcium homeostasis and purine metabolism in BA patients, involvement of the detected crystalline formations in the pathogenesis of BA obstruction bronchospasm and deterioration of sputum rheological properties.


Assuntos
Asma/metabolismo , Escarro/análise , Oligoelementos/análise , Adulto , Idoso , Cristalização , Feminino , Histocitoquímica , Humanos , Masculino , Pessoa de Meia-Idade , Análise Espectral , Escarro/metabolismo
4.
Ter Arkh ; 57(3): 53-4, 1985.
Artigo em Russo | MEDLINE | ID: mdl-4002165

RESUMO

Study of the clinical data concerning patients suffering from bronchial asthma and analysis of the autopsy data allow the conclusion about the presence of a pathogenetically validated symptomatic arterial hypertension including its drug patterns. The increased number of cases of bronchial asthma and arterial hypertension constellation attests to a considerable unbalance of the autonomous nervous system, alterations of the sympathoadrenal effects in such patients, which makes the clinical picture and course of modern bronchial asthma more complicated. The pathogenetic approach to the treatment of such patients characterized by hypersensitivity to the environmental factors, stress situations and to drugs which stimulate the sympathoadrenal system will permit one to avoid diagnostic, deontological errors, to choose sound therapy including measures aimed at preventing arterial hypertension itself.


Assuntos
Asma/complicações , Hipertensão/etiologia , Asma/fisiopatologia , Pressão Sanguínea , Doença Crônica , Humanos , Hipertensão/fisiopatologia
5.
Ter Arkh ; 65(3): 15-9, 1993.
Artigo em Russo | MEDLINE | ID: mdl-8059373

RESUMO

The data obtained on bronchial asthma (BA) occurrence in the hyperendemic opisthorchiasis focus in the western Siberia show BA in it to run a more severe and prognostically unfavourable course against the population from other Siberian regions safer by opisthorchiasis. The latter adapted to hepatobiliary system negatively affects the bronchi and lungs due to the involvement of eosinophilic and immunocomplex mechanisms damaging BA patients' shock organ. By means of additional antigenic stimulus, opisthorchiasis sensitization changes BA clinical manifestations and immunological manifestations status of BA patients dictating the necessity of immunological correction. High BA incidence was registered among subjects who had come from areas where opisthorchiasis was encountered less frequently.


Assuntos
Asma/epidemiologia , Reservatórios de Doenças/estatística & dados numéricos , Opistorquíase/epidemiologia , Adulto , Suscetibilidade a Doenças , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estações do Ano , Distribuição por Sexo , Sibéria/epidemiologia
10.
Phys Rev Lett ; 86(11): 2416-9, 2001 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-11289943

RESUMO

We report measurements on ropes of single-walled carbon nanotubes (SWNT) in low-resistance contact to nonsuperconducting (normal) metallic pads, at low voltage and at temperatures down to 70 mK. In one sample, we find a 2 orders of magnitude resistance drop below 0.55 K, which is destroyed by a magnetic field of the order of 1 T, or by a dc current greater than 2.5 microA. These features strongly suggest the existence of superconductivity in ropes of SWNT.

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