Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
Mais filtros

País/Região como assunto
Intervalo de ano de publicação
1.
Phys Rev Lett ; 131(19): 191001, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38000434

RESUMO

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station. The instrument, consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter with a total depth of 30 radiation lengths at normal incidence and a fine shower imaging capability, is optimized to measure the all-electron spectrum well into the TeV region. Because of the excellent energy resolution (a few percent above 10 GeV) and the outstanding e/p separation (10^{5}), CALET provides optimal performance for a detailed search of structures in the energy spectrum. The analysis uses data up to the end of 2022, and the statistics of observed electron candidates has increased more than 3 times since the last publication in 2018. By adopting an updated boosted decision tree analysis, a sufficient proton rejection power up to 7.5 TeV is achieved, with a residual proton contamination less than 10%. The observed energy spectrum becomes gradually harder in the lower energy region from around 30 GeV, consistently with AMS-02, but from 300 to 600 GeV it is considerably softer than the spectra measured by DAMPE and Fermi-LAT. At high energies, the spectrum presents a sharp break around 1 TeV, with a spectral index change from -3.15 to -3.91, and a broken power law fitting the data in the energy range from 30 GeV to 4.8 TeV better than a single power law with 6.9 sigma significance, which is compatible with the DAMPE results. The break is consistent with the expected effects of radiation loss during the propagation from distant sources (except the highest energy bin). We have fitted the spectrum with a model consistent with the positron flux measured by AMS-02 below 1 TeV and interpreted the electron+positron spectrum with possible contributions from pulsars and nearby sources. Above 4.8 TeV, a possible contribution from known nearby supernova remnants, including Vela, is addressed by an event-by-event analysis providing a higher proton-rejection power than a purely statistical analysis.

3.
Phys Rev Lett ; 130(21): 211001, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37295105

RESUMO

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.


Assuntos
Radiação Cósmica , Voo Espacial , Telescópios , Prótons , Elétrons
4.
Phys Rev Lett ; 130(17): 171002, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37172251

RESUMO

We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40 GeV to ∼250 TeV, for the first time with a single instrument in low Earth orbit. The measured spectrum shows evidence of a deviation of the flux from a single power law by more than 8σ with a progressive spectral hardening from a few hundred GeV to a few tens of TeV. This result is consistent with the data reported by space instruments including PAMELA, AMS-02, and DAMPE and balloon instruments including CREAM. At higher energy we report the onset of a softening of the helium spectrum around 30 TeV (total kinetic energy). Though affected by large uncertainties in the highest energy bins, the observation of a flux reduction turns out to be consistent with the most recent results of DAMPE. A double broken power law is found to fit simultaneously both spectral features: the hardening (at lower energy) and the softening (at higher energy). A measurement of the proton to helium flux ratio in the energy range from 60 GeV/n to about 60 TeV/n is also presented, using the CALET proton flux recently updated with higher statistics.

5.
Phys Rev Lett ; 129(10): 101102, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36112450

RESUMO

A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observation of a softening of the spectrum above 10 TeV is reported. The analysis is based on the data collected during ∼6.2 years of smooth operations aboard the International Space Station and covers a broader energy range with respect to the previous proton flux measurement by CALET, with an increase of the available statistics by a factor of ∼2.2. Above a few hundred GeV we confirm our previous observation of a progressive spectral hardening with a higher significance (more than 20 sigma). In the multi-TeV region we observe a second spectral feature with a softening around 10 TeV and a spectral index change from -2.6 to -2.9 consistently, within the errors, with the shape of the spectrum reported by DAMPE. We apply a simultaneous fit of the proton differential spectrum which well reproduces the gradual change of the spectral index encompassing the lower energy power-law regime and the two spectral features observed at higher energies.

6.
Phys Rev Lett ; 129(25): 251103, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36608255

RESUMO

We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4 GeV/n to 3.8 TeV/n based on the data collected by the Calorimetric Electron Telescope (CALET) during ∼6.4 yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E_{0}∼200 GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=-3.047±0.024 in the interval 25

7.
Phys Rev Lett ; 128(13): 131103, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426700

RESUMO

The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other transiron elements; therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and its relative abundance with respect to iron provide important information to estimate the abundances at the cosmic ray source and to model the Galactic propagation of heavy nuclei. However, only a few direct measurements of cosmic-ray nickel at energy larger than ∼3 GeV/n are available at present in the literature, and they are affected by strong limitations in both energy reach and statistics. In this Letter, we present a measurement of the differential energy spectrum of nickel in the energy range from 8.8 to 240 GeV/n, carried out with unprecedented precision by the Calorimetric Electron Telescope (CALET) in operation on the International Space Station since 2015. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The particle's energy is measured by a homogeneous calorimeter (1.2 proton interaction lengths, 27 radiation lengths) preceded by a thin imaging section (3 radiation lengths) providing tracking and energy sampling. This Letter follows our previous measurement of the iron spectrum [1O. Adriani et al. (CALET Collaboration), Phys. Rev. Lett. 126, 241101 (2021).PRLTAO0031-900710.1103/PhysRevLett.126.241101], and it extends our investigation on the energy dependence of the spectral index of heavy elements. It reports the analysis of nickel data collected from November 2015 to May 2021 and a detailed assessment of the systematic uncertainties. In the region from 20 to 240 GeV/n our present data are compatible within the errors with a single power law with spectral index -2.51±0.07.

8.
Phys Rev Lett ; 126(24): 241101, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34213922

RESUMO

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10 GeV/n to 2.0 TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50 GeV/n to 2 TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

9.
Phys Rev Lett ; 125(25): 251102, 2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33416351

RESUMO

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10 GeV/n to 2.2 TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200 GeV/n established with a significance >3σ. They have the same energy dependence with a constant C/O flux ratio 0.911±0.006 above 25 GeV/n. The spectral hardening is consistent with that measured by AMS-02, but the absolute normalization of the flux is about 27% lower, though in agreement with observations from previous experiments including the PAMELA spectrometer and the calorimetric balloon-borne experiment CREAM.

10.
Phys Rev Lett ; 122(18): 181102, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31144869

RESUMO

In this paper, we present the analysis and results of a direct measurement of the cosmic-ray proton spectrum with the CALET instrument onboard the International Space Station, including the detailed assessment of systematic uncertainties. The observation period used in this analysis is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved the very wide energy range necessary to carry out measurements of the spectrum from 50 GeV to 10 TeV covering, for the first time in space, with a single instrument the whole energy interval previously investigated in most cases in separate subranges by magnetic spectrometers (BESS-TeV, PAMELA, and AMS-02) and calorimetric instruments (ATIC, CREAM, and NUCLEON). The observed spectrum is consistent with AMS-02 but extends to nearly an order of magnitude higher energy, showing a very smooth transition of the power-law spectral index from -2.81±0.03 (50-500 GeV) neglecting solar modulation effects (or -2.87±0.06 including solar modulation effects in the lower energy region) to -2.56±0.04 (1-10 TeV), thereby confirming the existence of spectral hardening and providing evidence of a deviation from a single power law by more than 3σ.

11.
Phys Rev Lett ; 120(26): 261102, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004739

RESUMO

Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X_{0} at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below 1 TeV shows good agreement with Alpha Magnetic Spectrometer (AMS-02) data. In the energy region below ∼300 GeV, CALET's spectral index is found to be consistent with the AMS-02, Fermi Large Area Telescope (Fermi-LAT), and Dark Matter Particle Explorer (DAMPE), while from 300 to 600 GeV the spectrum is significantly softer than the spectra from the latter two experiments. The absolute flux of CALET is consistent with other experiments at around a few tens of GeV. However, it is lower than those of DAMPE and Fermi-LAT with the difference increasing up to several hundred GeV. The observed energy spectrum above ∼1 TeV suggests a flux suppression consistent within the errors with the results of DAMPE, while CALET does not observe any significant evidence for a narrow spectral feature in the energy region around 1.4 TeV. Our measured all-electron flux, including statistical errors and a detailed breakdown of the systematic errors, is tabulated in the Supplemental Material in order to allow more refined spectral analyses based on our data.

12.
Phys Rev Lett ; 119(18): 181101, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29219544

RESUMO

First results of a cosmic-ray electron and positron spectrum from 10 GeV to 3 TeV is presented based upon observations with the CALET instrument on the International Space Station starting in October, 2015. Nearly a half million electron and positron events are included in the analysis. CALET is an all-calorimetric instrument with total vertical thickness of 30 X_{0} and a fine imaging capability designed to achieve a large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum over 30 GeV can be fit with a single power law with a spectral index of -3.152±0.016 (stat+syst). Possible structure observed above 100 GeV requires further investigation with increased statistics and refined data analysis.

13.
Vestn Khir Im I I Grek ; 175(5): 13-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30422441

RESUMO

An analysis of data of carotid angiographies was made in 146 patients with chronic cerebrovascular disease. Combined lesions of the common and internal carotid artery with clinical signs were revealed in 2 (1,4%) patients. A crossed extraanatomic bypass from the left common carotid artery to the right internal carotid artery was performed in one patient. The orthotopic common-internal autovenous bypass on the right side was carried out for another patient. According to obtained results, the authors suggested that the orthotopic or extraanatomic common-internal carotid artery bypasses could be applied in case of impossibility of endovascular intervention, when patients had the combined atherosclerotic lesions of common carotid and internal carotid artery.


Assuntos
Artéria Carótida Primitiva , Artéria Carótida Interna , Estenose das Carótidas , Revascularização Cerebral/métodos , Transtornos Cerebrovasculares , Enxerto Vascular/métodos , Angiografia/métodos , Artéria Carótida Primitiva/diagnóstico por imagem , Artéria Carótida Primitiva/cirurgia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/cirurgia , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/fisiopatologia , Estenose das Carótidas/cirurgia , Transtornos Cerebrovasculares/etiologia , Transtornos Cerebrovasculares/fisiopatologia , Transtornos Cerebrovasculares/cirurgia , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
14.
Vestn Khir Im I I Grek ; 173(1): 12-7, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25055502

RESUMO

A retrospective analysis of data of 188 patients, who underwent a selective surgery for abdominal aortic aneurism showed, that all the patients had a cardiac pathology. Ischemic heart disease and arterial hypertension had 175 (93.0%) and 177 (94.1%) of patients, respectively. Chronic nonspecific lung disease was noted in 65.4% patients and kidney disease--in 48.9%. Different complications developed in early postoperative period in 47 (25%) patients, that resulted in fatal outcome in 20(10,6%). The most frequent complication was an acute renal insufficiency, which led to fatal outcome in 40% patients. Myocardial infarction and pneumonia took the second place in the structure of postoperative complications, one half of the fatal cases was due to these. Retrospective risk stratification assessment of the development of early postoperative complications and lethality was made by Glasgow Aneurysm Score (GAS) and angiosurgical model scale V-POSSUM. It was stated, that score was up to 84 according to GAS scale and up to 28 (V-POSSUM). That fact is the evidence of high risk of the operation. On the basis of ROC curves building, the conclusion was made about greater predictive ability of V-POSSUM scoring system.


Assuntos
Aneurisma da Aorta Abdominal , Hipertensão/epidemiologia , Isquemia Miocárdica/epidemiologia , Procedimentos Cirúrgicos Vasculares , Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/epidemiologia , Aneurisma da Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Abdominal/cirurgia , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/classificação , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/mortalidade , Curva ROC , Estudos Retrospectivos , Risco Ajustado , Medição de Risco , Fatores de Risco , Federação Russa/epidemiologia , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Procedimentos Cirúrgicos Vasculares/métodos , Procedimentos Cirúrgicos Vasculares/mortalidade
15.
Mol Gen Mikrobiol Virusol ; (4): 6-9, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24645271

RESUMO

DNA polymorphism is an important component of the interindividual variation in reactions of patients to the same drugs. In this work, evaluation of the association between polymorphisms in 106 genes involved in key processes of cellular activity (xenobiotic metabolism, DNA repair, the cell cycle, and apoptosis), and outcomes in a cohort of Yakut ovarian cancer patients receiving cisplatin-based chemotherapy was carried out. The polymorphism in the CDKN1B gene (rs34330) was found to be associated with complete tumor response and progression-free survival. SNPs in EPXH1 gene (rs2234922 and rs2260863) were correlated with hearing impairment. A SNP in NBN gene (rs1063045) was associated with severe emesis.


Assuntos
Cisplatino/administração & dosagem , Inibidor de Quinase Dependente de Ciclina p27/genética , Estudos de Associação Genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Apoptose/genética , Ciclo Celular/genética , Reparo do DNA/genética , Intervalo Livre de Doença , Feminino , Predisposição Genética para Doença , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Farmacogenética , Polimorfismo de Nucleotídeo Único , Federação Russa , Xenobióticos/metabolismo
16.
Vestn Khir Im I I Grek ; 172(2): 39-42, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24000677

RESUMO

The data of the follow-up study of 60 patients with wounds of the neck are presented in this article. The authors describe the volume and severity of injuries of the neck and at the same time examine the difficulties of diagnostics and treatment. The scope of investigations, the necessity of consultation of "narrow" specialist, the volume of surgical handbook and the conservative therapy are determined. The significance of the up-to-date methods of instrumental researches, such as computed tomography, Doppler tomography, are emphasized particularly for evaluation of the injury volume.


Assuntos
Serviço Hospitalar de Emergência , Lesões do Pescoço/cirurgia , Tomografia Computadorizada por Raios X/métodos , Ferimentos Penetrantes/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Lesões do Pescoço/diagnóstico por imagem , Estudos Retrospectivos , Índices de Gravidade do Trauma , Resultado do Tratamento , Ferimentos Penetrantes/diagnóstico por imagem , Adulto Jovem
17.
Vestn Khir Im I I Grek ; 172(2): 47-50, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24000679

RESUMO

Retrospective analysis of data in 188 patients showed, that chronic nonspecific pulmonary disease was diagnosed in 65.4% of all. Disorders of bronchial patency of different degrees of manifestation were noted in 61.2% and 19.7% of patients had a hypoxemia. Renal diseases were found in 59% of patients, resulting in the development of chronic renal insufficiency in 17%. The data obtained indicate, that the presence of coexisting pulmonary pathology directly influences the frequency and severity of respiratory complications after surgery, which can be the cause of fatal outcome. The presence of renal diseases results in three times higher risk of the development of postoperative renal complications.


Assuntos
Aneurisma da Aorta Abdominal/complicações , Insuficiência Renal/complicações , Insuficiência Respiratória/complicações , Procedimentos Cirúrgicos Vasculares , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/cirurgia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Insuficiência Renal/diagnóstico , Insuficiência Renal/epidemiologia , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Federação Russa/epidemiologia , Taxa de Sobrevida/tendências , Resultado do Tratamento
18.
Vestn Khir Im I I Grek ; 172(5): 77-81, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24640754

RESUMO

The rupture of infrarenal segment of aorta is the severe pathology in spite of modem diagnostics and the operation. This case is accompanied by negative results of treatment (lethality consists of 56,3%). The article presents the experience of treatment of 157 patients with the rupture of infrarenal segment of aorta in conditions of multifield hospital (Municipal hospital No 26). The authors highlighted the postoperative complications, their influence on negative outcome. It was shown, that the main reasons of negative outcome of such patients with abdominal aortic aneurism, complicated by the rupture, were an advanced age of patients, who had the complex of concomitant diseases and postoperative complications such as nosocomial pneumonia, cardiac problems and multiple organ failure due to massive acute hemorrhage.


Assuntos
Aorta Abdominal/cirurgia , Aneurisma da Aorta Abdominal/complicações , Ruptura Aórtica , Implante de Prótese Vascular , Complicações Pós-Operatórias , Idoso , Idoso de 80 Anos ou mais , Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Ruptura Aórtica/diagnóstico , Ruptura Aórtica/etiologia , Ruptura Aórtica/fisiopatologia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/métodos , Implante de Prótese Vascular/estatística & dados numéricos , Emergências , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/classificação , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/mortalidade , Radiografia , Análise de Sobrevida , Resultado do Tratamento , Ultrassonografia
19.
Vestn Khir Im I I Grek ; 172(1): 11-5, 2013.
Artigo em Russo | MEDLINE | ID: mdl-23808220

RESUMO

A retrospective analysis of the data of 188 patients with the infrarenal segment of the aortic aneurysm (ISAA) showed, that ischemic heart disease and arterial hypertension were diagnosed practically in all patients--175 (93.0%) and 177 (94.1%) patients respectively. A decreased retractor function of the myocardium was noted in 88 (46.8%) of patients. According to the findings of echocardiography 134 (71.3%) patients had the arterial hypertension of third degree. For the assessment of the influence of the accompanying cardiac pathology on the results of planned surgical treatment and systematization of postoperative cardiac complications the classification, which was proposed by R. B. Rutherford et al. and modified by A. V. Pokrovsky et al. was used. The obtained data point at a direct proportional relationship between the degree of the initial cardiac status, frequency and severity of postoperative cardiac complications in patients after resection of ISAA in 1.6-2.3 times.


Assuntos
Aneurisma da Aorta Abdominal , Hipertensão , Isquemia Miocárdica , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Vasculares , Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/etiologia , Aneurisma da Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Abdominal/cirurgia , Feminino , Testes de Função Cardíaca/métodos , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/epidemiologia , Isquemia Miocárdica/fisiopatologia , Complicações Pós-Operatórias/classificação , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Estudos Retrospectivos , Risco Ajustado/métodos , Fatores de Risco , Índice de Gravidade de Doença , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Procedimentos Cirúrgicos Vasculares/métodos
20.
Sovrem Tekhnologii Med ; 15(1): 53-60, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37388751

RESUMO

The aim of the study was to identify different degrees of dermal lesions in vulvar lichen sclerosus (VLS) using cross-polarization optical coherence tomography (CP OCT) based on attenuation coefficient to detect disease early manifestations and to monitor the effectiveness of treatment. Materials and Methods: The study included 10 patients without pathology and 39 patients with VLS diagnosed histologically. CP OCT was performed in vivo on the inner surface of the labia minora, in the main lesion area. From each scanning point, a 3.4×3.4×1.25-mm3 3D data array was obtained in 26 s. CP OCT examination results were compared with histological examination of specimens stained with Van Gieson's picrofuchsin.Quantitative analysis of OCT images was performed by measuring the attenuation coefficient in co-polarization and cross-polarization. For visual analysis, color-coded charts were developed based on OCT attenuation coefficients. Results: According to histological examination, all patients with VLS were divided into 4 groups as per dermal lesion degree: initial (8 patients); mild (7 patients); moderate (9 patients); severe (15 patients). Typical features of different degrees were interfibrillary edema up to 250 µm deep for initial degree, thickened collagen bundles without edema up to 350 µm deep for mild degree, dermis homogenization up to 700 µm deep for moderate degree, dermis homogenization and total edema up to 1200 µm deep for severe degree.Pathological processes in dermis during VLS like interfibrillary edema and collagen bundles homogenization were visualized using CP OCT method based on values of attenuation coefficient in co- and cross-polarization channels. However, CP OCT method appeared to be less sensitive to changes of collagen bundles thickness not allowing to distinguish thickened collagen bundles from normal ones with enough statistical significance. The CP OCT method was able to differentiate all degrees of dermal lesions among themselves. OCT attenuation coefficients differed from normal condition with statistical significance for all degrees of lesions, except for mild. Conclusion: For the first time, quantitative parameters for each degrees of dermis lesion in VLS, including initial degree, were determined by CP OCT method allowing to detect the disease at an early stage and to monitor the applied clinical treatment effectiveness.


Assuntos
Tomografia de Coerência Óptica , Líquen Escleroso Vulvar , Feminino , Humanos , Refração Ocular , Vulva , Líquen Escleroso Vulvar/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA