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1.
Adv Gerontol ; 33(2): 397-408, 2020.
Artículo en Ruso | MEDLINE | ID: mdl-32593259

RESUMEN

Never before in history, aging was such a significant factor for epidemics as it is now for the current COVID-19 pandemic, which features a drastic shift of mortality towards older ages. Our analysis of data on COVID-19-related mortality in Spain, Italy, and Sweden has shown that, in the range of 30 to 90 years of age, each dependency of the logarithm of mortality upon age is linear, and all regression lines are strictly parallel to those related to the total mortality in accordance with the Gompertz law. In all cases, irrespective of the stage and place of epidemic, mortality doubling time in this age range is close to 7,5 years. The rates of being infected with the SARS-CoV-2 coronavirus and of being diagnosed due to the symptomatic manifestations of the infection are dependent on age to a far lesser degree. With account for these observations, three messages are put forth: 1) Older persons are the principal victims of both SARS-CoV-2 and measures undertaken to control its spread; 2) Older persons are not the principal driving force of SARS-CoV-2 spread; 3) Older persons can and should be engaged in combating the pandemic and its consequences; however, not via selective social distancing and other discriminative measures. People aged over 65 years constitute a significant part of the current population. They have specific interests and needs, which deserve no less respect than those of any other age group. This includes the right for the quality of life that remains sustained under the emergency conditions. Since the prospects for controlling the SARS-CoV-2 are dubious, those in charge of decisions concerning «people aged above 65¼ should mind that currently, unlike in the medieval ages, 65+ is the individual future of almost everyone.


Asunto(s)
Envejecimiento , Infecciones por Coronavirus/epidemiología , Pandemias , Neumonía Viral/epidemiología , Anciano , COVID-19 , Infecciones por Coronavirus/mortalidad , Humanos , Neumonía Viral/mortalidad , Teoría Social
2.
Dokl Biochem Biophys ; 484(1): 82-84, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31012021

RESUMEN

It was found that the chemiluminescence intensity in native and recellularized tissues of rat muscular organs as well as in their decellularized scaffolds can serve as an express criterion that, along with ultrastructural analysis, makes it possible to perform quantitative assessment of the viability of cellular structures in biological samples of the diaphragm.


Asunto(s)
Diafragma/química , Mediciones Luminiscentes , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Ratas
3.
Bioprocess Biosyst Eng ; 41(12): 1851-1867, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30244423

RESUMEN

A method for the synthesis of ß-lactam antibiotic cefazolin (CEZ) by enzymatic acylation of 7-amino-3-(5-methyl-l,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (TDA) using immobilized cephalosporin-acid synthetase (IECASA) from recombinant E. coli strain VKPM B-12316 has been developed. A stepwise pH gradient designed on the basis of investigations on the solubility of components was applied for synthesis. This helped in avoiding the precipitation of TDA in the reaction when its initial concentration was high (150-200 mM). Thus, under optimal conditions a high yield of CEZ (relative to TDA) of 92-95% was obtained. Where the final reaction mixture contained 65-85 mg/mL of CEZ, 4-5 mg/mL of unreacted TDA, and 40-60 mg/mL of the by-product, 1(H)-tetrazolylacetic acid (TzAA). Testing of optimized CEZ synthesis using IECASA in a batch reactor has proved sufficiently high operational stability of the biocatalyst, with its residual activity after the 25th cycle accounting for about 83 ± 2% of its starting value. The half-inactivation period of IECASA was estimated as 85 cycles of CEZ synthesis.


Asunto(s)
Aciltransferasas/química , Biocatálisis , Cefazolina/síntesis química , Enzimas Inmovilizadas/química , Acilación , Cefazolina/química , Escherichia coli/enzimología , Proteínas Recombinantes/química
4.
Angiol Sosud Khir ; 24(4): 169-175, 2018.
Artículo en Ruso | MEDLINE | ID: mdl-30531785

RESUMEN

A ruptured thoracoabdominal aortic aneurysm is an urgent situation requiring emergency surgery during which it is necessary to decrease the scope of the intervention in a patient at an extremely high surgical risk. A combination of surgical and endovascular techniques makes it possible to minimize surgical injury, blood loss, to shorten the duration of internal organs ischaemia, to reduce the risk of paraplegia. Presented herein are the results of emergency hybrid intervention for a ruptured thoracoabdominal aortic aneurysm, accompanied and followed by description of the technical aspects of performing the surgical and endovascular stages. The early postoperative period was complicated by thrombosis of the left superficial femoral artery on the background of atherosclerotic lesions, which was successfully eliminated by means of endovascular intervention with endovascular prosthetic repair. After 10 months, the patient underwent a cardiosurgical intervention. Combining surgical and endovascular techniques made it possible in an emergency situation to save the patient's life and to provide its good quality in the remote period of follow up (4 years after the hybrid operation).


Asunto(s)
Aneurisma Roto , Aneurisma de la Aorta Torácica , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Complicaciones Posoperatorias , Trombosis de la Vena , Aneurisma Roto/complicaciones , Aneurisma Roto/diagnóstico , Aneurisma Roto/fisiopatología , Aneurisma Roto/cirugía , Aneurisma de la Aorta Torácica/diagnóstico , Aneurisma de la Aorta Torácica/fisiopatología , Aneurisma de la Aorta Torácica/cirugía , Aortografía/métodos , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/métodos , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/métodos , Hematoma/diagnóstico , Hematoma/etiología , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector/métodos , Tempo Operativo , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/cirugía , Reoperación/métodos , Ajuste de Riesgo/métodos , Stents , Resultado del Tratamiento , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/etiología , Trombosis de la Vena/cirugía
5.
Phys Rev Lett ; 118(24): 246601, 2017 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-28665644

RESUMEN

Recent theoretical studies of topologically nontrivial electronic states in Kondo insulators have pointed to the importance of spin-orbit coupling (SOC) for stabilizing these states. However, systematic experimental studies that tune the SOC parameter λ_{SOC} in Kondo insulators remain elusive. The main reason is that variations of (chemical) pressure or doping strongly influence the Kondo coupling J_{K} and the chemical potential µ-both essential parameters determining the ground state of the material-and thus possible λ_{SOC} tuning effects have remained unnoticed. Here, we present the successful growth of the substitution series Ce_{3}Bi_{4}(Pt_{1-x}Pd_{x})_{3} (0≤x≤1) of the archetypal (noncentrosymmetric) Kondo insulator Ce_{3}Bi_{4}Pt_{3}. The Pt-Pd substitution is isostructural, isoelectronic, and isosize, and it therefore is likely to leave J_{K} and µ essentially unchanged. By contrast, the large mass difference between the 5d element Pt and the 4d element Pd leads to a large difference in λ_{SOC}, which thus is the dominating tuning parameter in the series. Surprisingly, with increasing x (decreasing λ_{SOC}), we observe a Kondo insulator to semimetal transition, demonstrating an unprecedented drastic influence of the SOC. The fully substituted end compound Ce_{3}Bi_{4}Pd_{3} shows thermodynamic signatures of a recently predicted Weyl-Kondo semimetal.

6.
Adv Gerontol ; 30(4): 505-515, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-28968024

RESUMEN

This review article is devoted to the distinctive aspects of population aging in the Republic of Kazakhstan. The demographic parameters of aging are analyzed, as well as their implications for various spheres of Kazakhstan society, such as health care, social security and social services.


Asunto(s)
Envejecimiento , Transición de la Salud , Atención a la Salud , Humanos , Kazajstán , Dinámica Poblacional , Bienestar Social , Servicio Social
7.
Adv Gerontol ; 30(5): 644-651, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-29322728

RESUMEN

This article consists of the concluding sections of the review devoted to the issues of population aging in the Republic of Kazakhstan. The presented material is intended to substantiate strategic approaches for addressing the evolving process of population aging in Kazakhstan.


Asunto(s)
Envejecimiento , Atención a la Salud , Transición de la Salud , Política Pública , Humanos , Kazajstán
8.
Angiol Sosud Khir ; 23(4): 55-59, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-29240056

RESUMEN

A multilevel aneurysmatic lesion of the aorta is a rare pathology. The authors describe herein a clinical case report regarding stage-wise treatment of a patient presenting with aneurysms of the thoracic and abdominal portions of the aorta and a haemodynamically significant lesion of coronary and carotid arteries. Strategy of surgical management was decided upon collegially. Successful endoprosthetic repair of the aneurysm of the thoracic portion of the aorta required closure of the left carotid artery with a graft, which, taking into consideration an existing occlusion of the right internal carotid artery, demanded preliminary carotid-subclavian bypass grafting. The clinical course of progressing angina pectoris (75% stenosis of the anterior descending artery with a poststenotic aneurysm) also increased the risk of the surgical stage. The authors provide a detailed description of the planning procedure, stages, and technical aspects of the operations performed. No complications were encountered. The duration of the follow up period amounted to 15 months. There was regression of the symptomatic manifestations, accompanied and followed by complete thrombosis of the aneurysmatic zones stented. A hybrid approach demonstrated efficacy and safety in staged treatment of complicated combined pathology of the aorta and its branches.


Asunto(s)
Aneurisma de la Aorta Torácica , Enfermedades de las Arterias Carótidas , Enfermedad de la Arteria Coronaria , Procedimientos Endovasculares/métodos , Injerto Vascular/métodos , Anciano , Aorta/diagnóstico por imagen , Aorta/cirugía , Aneurisma de la Aorta Torácica/complicaciones , Aneurisma de la Aorta Torácica/diagnóstico , Aneurisma de la Aorta Torácica/fisiopatología , Aneurisma de la Aorta Torácica/cirugía , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/cirugía , Enfermedades de las Arterias Carótidas/complicaciones , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/cirugía , Angiografía por Tomografía Computarizada/métodos , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/cirugía , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/cirugía , Humanos , Masculino , Ajuste de Riesgo , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
9.
Fiziol Cheloveka ; 41(4): 110-8, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-26485795

RESUMEN

The rheological properties of blood (viscosity, concentration of red blood cells, erythrocyte sedimantation rate, prothrombin index, and fibrinogen and blood lipid concentration) were studied in apparently healthy subjects of both sexes within the age range from 1 to 75 years. We observed an increase in blood viscosity from infancy to adulthood, followed by a decrease in older age in males. A progressive increase in viscosity is observed in females with aging. We determined three age periods during which the viscosity values remain constant: 1) from the period of early infancy to the second childhood (3.6 ± 0.07 mPa s regardless of sex); 2) from adolescence to the second period of adulthood (5.1 ± 0.06 in men; 4.3 ± 0.05 mPa s in women); 3) elderly and senile age (4.7 ± 0.13 in men; 4.4 ± 0.09 mPa s in women). Sex-related differences in the absolute value of blood viscosity (p < 0.001) were discovered in the period of adulthood. Moreover, we observed sex-related differences in the values of determination coefficients of interrelation between viscosity and the level of red blood cells (R(M)2 = 0.41, p < 0.001; R(F)2 = 0.35, p < 0.001), and viscosity and cholesterol level (R(M)2 = 0.47, p < 0.001; R(F)2 = 0.68, p < 0.001) among men and women. The factor analysis showed that blood viscosity correlates with the concentration of red blood cells by 28%; with the level of fibrinogen, by 23%; with the cholesterol concentration, by 20%.


Asunto(s)
Envejecimiento/sangre , Viscosidad Sanguínea , Colesterol/sangre , Agregación Eritrocitaria , Fibrinógeno/metabolismo , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Preescolar , Recuento de Eritrocitos , Femenino , Hemorreología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Caracteres Sexuales , Adulto Joven
10.
Nat Mater ; 12(12): 1096-101, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24056804

RESUMEN

The increasing worldwide energy consumption calls for the design of more efficient energy systems. Thermoelectrics could be used to convert waste heat back to useful electric energy if only more efficient materials were available. The ideal thermoelectric material combines high electrical conductivity and thermopower with low thermal conductivity. In this regard, the intermetallic type-I clathrates show promise with their exceedingly low lattice thermal conductivities. Here we report the successful incorporation of cerium as a guest atom into the clathrate crystal structure. In many simpler intermetallic compounds, this rare earth element is known to lead, through the Kondo interaction, to strong correlation phenomena including the occurrence of giant thermopowers at low temperatures. Indeed, we observe a 50% enhancement of the thermopower compared with a rare-earth-free reference material. Importantly, this enhancement occurs at high temperatures and we suggest that a rattling-enhanced Kondo interaction underlies this effect.

11.
Adv Gerontol ; 27(2): 213-24, 2014.
Artículo en Ruso | MEDLINE | ID: mdl-25306650

RESUMEN

This review article is devoted to the issues of international cooperation on ageing. It aims at describing the basic areas of cooperation and introducing its major players. Within the limited length of a journal article it is hardly possible to offer an exhaustive presentation of all available information; thus the article strives to provide a general orientation within the selected themes. The authors are hopeful that the presented materials will be of interest to the policy oriented researchers, policy makers and professionals working in the field of ageing and related areas such as social security, health and social services etc., as well as to the activists of non-governmental organizations.


Asunto(s)
Práctica Clínica Basada en la Evidencia/organización & administración , Servicios de Salud para Ancianos , Cooperación Internacional , Anciano , Envejecimiento , Predicción , Servicios de Salud para Ancianos/normas , Servicios de Salud para Ancianos/tendencias , Disparidades en el Estado de Salud , Humanos , Investigación/tendencias , Agencias Voluntarias de Salud
12.
Fiziol Cheloveka ; 40(5): 93-102, 2014.
Artículo en Ruso | MEDLINE | ID: mdl-25711100

RESUMEN

The research of the ultrasound diameter, linear velocity and the resistance of internal carotid arteries of 647 people of both sexes aged from one to 74 years was conducted. Additionally, shear stress and the Reynolds number were calculated. During the period from early childhood to adolescence and from the first mature to old age there is an increase in the diameter of the internal carotid arteries. The phases of increased vascular resistance by the first period of childhood, adolescence and old age are observed. Volumetric flow rate has relatively stable parameters till adolescence, then it declines by old age. The average linear velocity, shear stress, and the Reynolds number diminish progressively twice with age. Laminar blood flow with local twists in the early stages of postnatal ontogenesis is characteristic of internal carotid arteries. The diameter of internal carotid arteries, vascular resistance index, blood flow velocity are higher in males than in females during most age periods. Shear stress in both internal carotid arteries during the age periods studied is symmetrical and has no sex differences.


Asunto(s)
Factores de Edad , Velocidad del Flujo Sanguíneo/fisiología , Arteria Carótida Interna/fisiología , Hemodinámica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Caracteres Sexuales
13.
Nat Mater ; 11(3): 189-94, 2012 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-22231597

RESUMEN

How ground states of quantum matter transform between one another reveals deep insights into the mechanisms stabilizing them. Correspondingly, quantum phase transitions are explored in numerous materials classes, with heavy-fermion compounds being among the most prominent ones. Recent studies in an anisotropic heavy-fermion compound have shown that different types of transitions are induced by variations of chemical or external pressure, raising the question of the extent to which heavy-fermion quantum criticality is universal. To make progress, it is essential to broaden both the materials basis and the microscopic parameter variety. Here, we identify a cubic heavy-fermion material as exhibiting a field-induced quantum phase transition, and show how the material can be used to explore one extreme of the dimensionality axis. The transition between two different ordered phases is accompanied by an abrupt change of Fermi surface, reminiscent of what happens across the field-induced antiferromagnetic to paramagnetic transition in the anisotropic YbRh2Si2. This finding leads to a materials-based global phase diagram--a precondition for a unified theoretical description.


Asunto(s)
Cerio/química , Paladio/química , Anisotropía , Metales/química , Transición de Fase , Dióxido de Silicio/química , Iterbio/química
14.
Adv Gerontol ; 26(4): 585-93, 2013.
Artículo en Ruso | MEDLINE | ID: mdl-24738244

RESUMEN

In this article the information on policy action on aging in the CIS countries and Georgia (CIS+) are presented and discussed. The process of implementation of the Madrid International Plan of Action on Aging (MIPAA) from 2002 through 2012 is chosen as a framework for analyzing the government policy on ageing. The article begins with a concise overview of the demographic situation in the CIS+ countries, which belong to various stages of demographic transition. In its concluding part, the article presents the policy goals for implementing MIPAA during its third implementation cycle (2013-2017).


Asunto(s)
Envejecimiento , Servicios de Salud para Ancianos , Programas Médicos Regionales , Regulación Gubernamental , Implementación de Plan de Salud , Directrices para la Planificación en Salud , Servicios de Salud para Ancianos/normas , Servicios de Salud para Ancianos/tendencias , Humanos , Cooperación Internacional , Dinámica Poblacional/tendencias , Programas Médicos Regionales/legislación & jurisprudencia , Programas Médicos Regionales/tendencias , Federación de Rusia , España
15.
Mol Biol (Mosk) ; 46(1): 139-46, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-22642111

RESUMEN

P66shc protein is an alternative transcript product of SHC1 gene. While two other isoforms (p52shc and p46shc) have adaptor function in RAS signaling pathway, p66shc regulates reactive oxygen species (ROS) level. P66shc genome knockout significantly extends lifespan in mice. Though p66shc was determined to translocate into mitochondria and led to increase in intracellular ROS, the mechanism by which the protein take part in signaling pathways that regulates resistance to cellular stresses remains poorly studied. P66shc has an important role in carcinogenesis and its increased expression correlates with poor prognosis in colon cancer. In this work we have applied RNA interference using lentiviral constructions that express short hairpin RNA (shRNA) against N-terminal CH2 domain of p66shc isoform. Using this approach p66 but not p52 and p46 SHC1 isoform expression was selectively suppressed in colon carcinoma RKO cells. RKO cells with p66shc knockdown have shown to be more resistant to oxidative stress induced by hydrogen peroxide or serum starvation. Fragmentation of mitochondria that depends on mitochondrial ROS accumulation during oxidative stress was significantly decreased in this cells. The data obtained are in agreement with hypothesis that p66shc participates in ROS accumulation in mitochondria and by this means promotes induction of apoptosis.


Asunto(s)
Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas Adaptadoras de la Señalización Shc/genética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Empalme Alternativo/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Neoplasias del Colon/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo , Isoformas de Proteínas/genética , Estructura Terciaria de Proteína/genética , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/análisis , Transducción de Señal/genética , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src
16.
Vavilovskii Zhurnal Genet Selektsii ; 26(8): 721-732, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36694717

RESUMEN

A vascular system in plants is a product of aromorphosis that enabled them to colonize land because it delivers water, mineral and organic compounds to plant organs and provides effective communications between organs and mechanical support. Vascular system development is a common object of fundamental research in plant development biology. In the model plant Arabidopsis thaliana, early stages of vascular tissue formation in the root are a bright example of the self-organization of a bisymmetric (having two planes of symmetry) pattern of hormone distribution, which determines vascular cell fates. In the root, vascular tissue development comprises four stages: (1) specification of progenitor cells for the provascular meristem in early embryonic stages, (2) the growth and patterning of the embryo provascular meristem, (3) postembryonic maintenance of the cell identity in the vascular tissue initials within the root apical meristem, and (4) differentiation of their descendants. Although the anatomical details of A. thaliana root vasculature development have long been known and described in detail, our knowledge of the underlying molecular and genetic mechanisms remains limited. In recent years, several important advances have been made, shedding light on the regulation of the earliest events in provascular cells specification. In this review, we summarize the latest data on the molecular and genetic mechanisms of vascular tissue patterning in A. thaliana root. The first part of the review describes the root vasculature ontogeny, and the second reconstructs the sequence of regulatory events that underlie this histogenesis and determine the development of the progenitors of the vascular initials in the embryo and organization of vascular initials in the seedling root.

17.
Nat Commun ; 12(1): 4341, 2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34290244

RESUMEN

Some of the highest-transition-temperature superconductors across various materials classes exhibit linear-in-temperature 'strange metal' or 'Planckian' electrical resistivities in their normal state. It is thus believed by many that this behavior holds the key to unlock the secrets of high-temperature superconductivity. However, these materials typically display complex phase diagrams governed by various competing energy scales, making an unambiguous identification of the physics at play difficult. Here we use electrical resistivity measurements into the micro-Kelvin regime to discover superconductivity condensing out of an extreme strange metal state-with linear resistivity over 3.5 orders of magnitude in temperature. We propose that the Cooper pairing is mediated by the modes associated with a recently evidenced dynamical charge localization-delocalization transition, a mechanism that may well be pertinent also in other strange metal superconductors.

18.
Radiats Biol Radioecol ; 50(5): 552-9, 2010.
Artículo en Ruso | MEDLINE | ID: mdl-21261007

RESUMEN

There are cases of development of a convulsive syndrome at influence of electromagnetic field (EMF) in physiotherapy practice, and in conditions of a professional work. There is a point of view that EMF can render medical effect at treatment of a epilepsy syndrome. Some publications specify on develop of epilepsy convulsions in experiment at EMF of various frequencies exposure. Four conditions which can promote development of convulsions at EMF exposure are considered.


Asunto(s)
Encéfalo/efectos de la radiación , Campos Electromagnéticos/efectos adversos , Magnetoterapia/efectos adversos , Convulsiones/etiología , Animales , Encéfalo/fisiopatología , Teléfono Celular , Humanos , Exposición Profesional , Convulsiones/fisiopatología , Síndrome
19.
Science ; 231(4743): 1271-3, 1986 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-17839563

RESUMEN

From October 1983 to July 1984, the north hemisphere of Venus, from latitude 30 degrees to latitude 90 degrees , was mapped by means of the radar imagers and altimeters of the spacecraft Venera 15 and Venera 16. This report presents the results of the radar mapping of the Maxwell Montes region, one of the most interesting features of Venus' surface. A radar mosaic map and contour map have been compiled.

20.
J Phys Condens Matter ; 21(25): 254202, 2009 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-21828426

RESUMEN

A dimensional crossover of superconducting fluctuations in an external magnetic field, applied parallel to the layers, has been found for superconductor/ferromagnet bilayers of Nb/Cu(41)Ni(59). By lowering the temperature, a reduction of the superconducting nuclei size occurs. As soon as the size of the nuclei becomes smaller than the thickness of the superconducting bilayer structure, the dimensionality changes. The temperature dependence of the fluctuation conductivity exhibits a 2D behaviour in zero and weak magnetic fields in the vicinity of the critical temperature, switching to a 3D behaviour in a strong magnetic field at low temperatures.

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