Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
1.
Phys Chem Chem Phys ; 26(16): 12725-12737, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38616653

RESUMO

C-I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed by site-selective ionization at the I 4d edge using intense XUV pulses, which induce multiple charges initially localized to the iodine atom. At C-I separations below the critical distance for charge transfer (CT), charge can redistribute around the molecule leading to Coulomb explosion and charged fragments with high kinetic energy. At greater C-I separations, beyond the critical distance, CT is no longer possible and the measured kinetic energies of the charged iodine atoms report on the neutral dissociation process. The time and momentum resolved measurements allow determination of the timescales and the respective product momentum and kinetic energy distributions for both isomers, which are interpreted in terms of rival 'direct' and 'indirect' dissociation pathways. The measurements are compared with a classical over the barrier model, which reveals that the onset of the indirect dissociation process is delayed by ∼1 ps relative to the direct process. The kinetics of the two processes show no discernible difference between the two parent isomers, but the branching between the direct and indirect dissociation channels and the respective product momentum distributions show isomer dependencies. The greater relative yield of indirect dissociation products from 262 nm photolysis of 3-iodothiophene (cf. 2-iodothiophene) is attributed to the different partial cross-sections for (ring-centred) π∗ ← π and (C-I bond localized) σ∗ ← (n/π) excitation in the respective parent isomers.

2.
Heart Vessels ; 39(8): 754-762, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38568474

RESUMO

The utility of assessment of cardiovascular calcifications for predicting stroke incidence remains unclear. This study assessed the relationship between cardiovascular calcifications including coronary artery calcification (CAC), aortic valve (AVC), and aortic root (ARC) assessed by coronary computed tomography (CT) and stroke incidence in patients with suspected CAD. In this multicenter prospective cohort study, 1187 patients suspected of CAD who underwent coronary CT were enrolled. Cardiovascular events including stroke were documented. Hazard ratio (HR) and confidence interval (CI) were assessed by Cox proportional hazard model adjusted for the Framingham risk score. C statistics for stroke incidence were also examined by models including cardiovascular calcifications. A total of 980 patients (mean age, 65 ± 7 years; females, 45.8%) were assessed by the CAC, AVC, and ARC Agatston scores. During a median follow-up of 4.0 years, 19 patients developed stroke. Cox proportional hazard model showed severe CAC (Agatston score ≥ 90th percentile [580.0 value]) and presence of AVC and ARC were associated with stroke incidence (HR; 10.33 [95% CI; 2.08-51.26], 3.08 [1.19-7.98], and 2.75 [1.03-7.30], respectively). C statistic in the model with CAC and AVC severity for predicting stroke incidence was 0.841 (95% CI; 0.761-0.920), which was superior to the model with CAC alone (0.762 [95% CI; 0.665-0.859], P < 0.01). CAC, AVC, and ARC were associated with stroke incidence in patients suspected of CAD. Assessment of both CAC and AVC may be useful for prediction of stroke incidence.


Assuntos
Doença da Artéria Coronariana , Prevenção Primária , Acidente Vascular Cerebral , Calcificação Vascular , Humanos , Feminino , Masculino , Incidência , Idoso , Estudos Prospectivos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Calcificação Vascular/epidemiologia , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/diagnóstico , Fatores de Risco , Medição de Risco/métodos , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico , Prevenção Primária/métodos , Pessoa de Meia-Idade , Angiografia Coronária/métodos , Valva Aórtica/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Seguimentos
3.
Phys Chem Chem Phys ; 25(21): 14836-14847, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37198941

RESUMO

To understand the mechanism underlying the high radio-sensitisation of living cells possessing brominated genomic DNA, X-ray photoelectron spectroscopy (XPS) using synchrotron X-rays with energies of 2000 or 2500 eV was used to study brominated and nonbrominated nucleobases, nucleosides and nucleotides. The bromine atom significantly reduced the energy gap between the valence and conduction states, although the core level states were not greatly affected. This finding was supported by quantum chemical calculation for the nucleobases and nucleosides. Our findings strongly indicate that the energy gaps between the valence and conduction levels of the molecules are significantly reduced by bromination. Furthermore, the brominated molecules are more likely to produce inelastic scattering low energy electrons upon exposure to 2000 or 3000 eV X-rays. This modification of electronic properties around the brominated group may both facilitate electron transfer to the brominated site in DNA and increase the probability of reaction with low energy electrons. These processes can induce DNA damage, presumably resulting in debromination of the uracil moiety and a subsequent cytotoxic effect.


Assuntos
Bromo , DNA , DNA/química , Uracila/química , Dano ao DNA
4.
Heart Vessels ; 38(4): 562-569, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36224476

RESUMO

To assess aortic valve calcification (AVC) and aortic root calcification (ARC) and to examine their usefulness for predicting major adverse cardiovascular events (MACE). This multicenter prospective cohort study recruited 1187 patients suspected of coronary artery disease (CAD) who underwent coronary computed tomography. MACE included cardiovascular death, myocardial infarction, stroke, revascularization and hospitalization for unstable angina, heart failure or aortic disease. Cox proportional hazard model and C-statistic were used to assess mutual associations between Framingham risk score, coronary artery calcification (CAC) and AVC or ARC with incident MACE. A total of 980 patients (mean age, 65 ± 7 years; female, 45.8%) with assessment of AVC and ARC Agatston scores were analyzed. Among them, 86 developed MACE during a median follow-up of 4.04 years. Cox proportional hazard analyses showed that the presence or severity of AVC and ARC was significantly associated with MACE development after adjusting the CAC Agatston score. Compared with the model of Framingham risk score alone, C-statistics of the model adding AVC or ARC Agatston score to Framingham risk score increased (ΔC-statistic; + 0.013 or + 0.032, respectively). However, they were not superior to the model adding CAC Agatston (ΔC-statistic; - 0.077 and - 0.058, respectively). AVC or ARC on the top of CAC was a predictive factor for increased MACE in patients with suspected CAD. However, an additional model of AVC or ARC score to Framingham risk score was not as effective as that of CAC Agatston score.


Assuntos
Doença da Artéria Coronariana , Calcificação Vascular , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Valva Aórtica , Aorta Torácica , Estudos Prospectivos , Fatores de Risco
5.
BMC Med Imaging ; 22(1): 26, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35148697

RESUMO

BACKGROUND: To clarify the differences in diaphragm thickness between male and female participants in healthy young adults with ultrasonography using the mean intima media thickness (IMT) method and to investigate the relationship between diaphragm thickness and respiratory pressure. METHODS: Twenty-nine healthy individuals (16 females and 13 males) participated in the study. Diaphragm thickness was measured at total lung capacity (TLC) and at functional residual capacity (FRC) in each participant. We measured the diaphragm thickness using a method for mean intima media thickness. Moreover, change ratio of diaphragm thickness was calculated with the diaphragm thickness at TLC and FRC. RESULTS: Mean diaphragm thicknesses at FRC in males were significantly narrower than those in females (p < 0.001). The change ratio of diaphragm thickness was significantly augmented in males compared with that in females (p < 0.001). There was a positive correlation between the change ratio of diaphragm thickness and pulmonary function data and respiratory muscle strength in healthy young adults. CONCLUSIONS: The change ratio of diaphragm thickness using the IMT method can be accurately performed with a high degree of reproducibility by clinical laboratory technicians and may be a useful indicator for evaluating diaphragm muscle strength.


Assuntos
Diafragma/anatomia & histologia , Ultrassonografia , Adulto , Espessura Intima-Media Carotídea , Diafragma/diagnóstico por imagem , Diafragma/fisiologia , Feminino , Capacidade Residual Funcional , Voluntários Saudáveis , Humanos , Masculino , Fatores Sexuais , Capacidade Pulmonar Total , Adulto Jovem
6.
Phys Chem Chem Phys ; 22(5): 2648-2659, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31436275

RESUMO

Momenta of ions from diiodomethane molecules after multiple ionization by soft-X-ray free-electron-laser pulses are measured. Correlations between the ion momenta are extracted by covariance methods formulated for the use in multiparticle momentum-resolved ion time-of-flight spectroscopy. Femtosecond dynamics of the dissociating multiply charged diiodomethane cations is discussed and interpreted by using simulations based on a classical Coulomb explosion model including charge evolution.

7.
J Stroke Cerebrovasc Dis ; 29(4): 104608, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31941580

RESUMO

A 57-year-old man with atherosclerosis obliterans was admitted with sudden-onset sensory aphasia and right hemiparesis. Brain MRI revealed acute cerebral infarctions in the left temporal lobe and magnetic resonance angiography showed occlusion of the posterior branch of the left middle cerebral artery. Transesophageal echocardiography and ultrasonography respectively confirmed a patent foramen ovale and deep vein thrombosis in the bilateral femoral veins. Blood findings showed low protein S antigen, low protein S activity, and a missense mutation of the PROS 1 gene. The administration of apixaban 10 mg BID prevented ischemic stroke recurrence and decreased the deep vein thrombosis. These outcomes indicated that apixaban may be alternative to warfarin for the secondary prevention of ischemic stroke in a patient with a protein S deficiency.


Assuntos
Isquemia Encefálica/prevenção & controle , Inibidores do Fator Xa/uso terapêutico , Deficiência de Proteína S/tratamento farmacológico , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Prevenção Secundária , Acidente Vascular Cerebral/prevenção & controle , Trombose Venosa/prevenção & controle , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/etiologia , Proteínas de Ligação ao Cálcio/genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Proteína S , Deficiência de Proteína S/complicações , Deficiência de Proteína S/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Resultado do Tratamento , Trombose Venosa/diagnóstico , Trombose Venosa/etiologia
8.
J Stroke Cerebrovasc Dis ; 29(5): 104597, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32057655

RESUMO

We report a 58-year-old woman who suddenly developed brain infarction with weakness of the left lower extremity and left perioral dysesthesia during postoperative tamoxifen therapy for breast cancer and prednisolone therapy for rheumatoid arthritis. Diffusion-weighted images detected multiple areas of hyperintensity in the posterior circulation system of the brain. Despite extensive examinations, we could not identify any embolic sources except hypoplasia of the right vertebral artery. We found decreased activity of protein C against its antigen level (activity: 59% versus antigen: 122%) with enhanced activity of coagulation factor VIII (178%) and von Willebrand factor (285%). DNA sequencing identified trinucleotide deletion of the PROC gene leading to 1 amino acid deletion at Lys-193 (p.Lys193del). We speculate that the PROC gene polymorphism may have participated in tamoxifen- and prednisolone- associated hypercoagulable state, leading to development of an embolic stroke in this patient.


Assuntos
Coagulação Sanguínea/genética , Embolia Intracraniana/etiologia , Deficiência de Proteína C/genética , Proteína C/genética , Deleção de Sequência , Acidente Vascular Cerebral/etiologia , Anticoagulantes/uso terapêutico , Antineoplásicos Hormonais/efeitos adversos , Coagulação Sanguínea/efeitos dos fármacos , Feminino , Predisposição Genética para Doença , Glucocorticoides/efeitos adversos , Humanos , Embolia Intracraniana/sangue , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/tratamento farmacológico , Metilprednisolona/efeitos adversos , Pessoa de Meia-Idade , Fármacos Neuroprotetores/uso terapêutico , Fenótipo , Deficiência de Proteína C/sangue , Deficiência de Proteína C/complicações , Deficiência de Proteína C/diagnóstico , Recidiva , Fatores de Risco , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Tamoxifeno/efeitos adversos , Resultado do Tratamento
9.
Stroke ; 50(6): 1586-1589, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31035902

RESUMO

Background and Purpose- As a prespecified post hoc analysis of the J-STARS (Japan Statin Treatment Against Recurrent Stroke) Echo Study, the 5-year stroke recurrence rate according to the baseline mean carotid intima-media thickness (IMT) with and without pravastatin treatment was investigated. Methods- Patients were randomly assigned to receive pravastatin 10 mg/day (pravastatin group) or control group (nonstatin treatment; 1:1) for 5 years. Baseline mean IMT of the common carotid artery was measured by ultrasonography. Cox proportional hazards models were used to investigate whether the stroke (any ischemic stroke, atherothrombotic brain infarction, or lacunar infarction) recurrence rate was different according to tertiles of baseline mean IMT. Results- A total of 793 patients, including 388 in the pravastatin group and 405 in the control group, were investigated. In the control group, Cox proportional hazards models showed that participants in the highest tertile IMT group (≥0.931 mm) had a higher rate of atherothrombotic brain infarction than those in the lowest tertile IMT group (<0.812 mm; [hazard ratio, 9.08; 95% CI, 1.15-71.43]). Patients in the pravastatin group had a lower risk of atherothrombotic brain infarction than those in the control group only in the highest tertile IMT group by the log-rank test ( P value=0.045). Conclusions- Long-term pravastatin administration may prevent the occurrence of atherothrombotic brain infarction in noncardioembolic infarction patients with the highest tertile IMT. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00361530.


Assuntos
Infarto Encefálico , Espessura Intima-Media Carotídea , Pravastatina/administração & dosagem , Acidente Vascular Cerebral , Idoso , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/epidemiologia , Infarto Encefálico/prevenção & controle , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle
10.
J Chem Phys ; 151(10): 104308, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521092

RESUMO

We have investigated the ionization and fragmentation of a metallo-endohedral fullerene, Sc3N@C80, using ultrashort (10 fs) x-ray pulses. Following selective ionization of a Sc (1s) electron (hν = 4.55 keV), an Auger cascade leads predominantly to either a vibrationally cold multiply charged parent molecule or multifragmentation of the carbon cage following a phase transition. In contrast to previous studies, no intermediate regime of C2 evaporation from the carbon cage is observed. A time-delayed, hard x-ray pulse (hν = 5.0 keV) was used to attempt to probe the electron transfer dynamics between the encapsulated Sc species and the carbon cage. A small but significant change in the intensity of Sc-containing fragment ions and coincidence counts for a delay of 100 fs compared to 0 fs, as well as an increase in the yield of small carbon fragment ions, may be indicative of incomplete charge transfer from the carbon cage on the sub-100 fs time scale.

11.
J Chem Phys ; 151(18): 184305, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31731862

RESUMO

Using electron spectroscopy, we investigated the nanoplasma formation process generated in xenon clusters by intense soft x-ray free electron laser (FEL) pulses. We found clear FEL intensity dependence of electron spectra. Multistep ionization and subsequent ionization frustration features are evident for the low FEL-intensity region, and the thermal electron emission emerges at the high FEL intensity. The present FEL intensity dependence of the electron spectra is well addressed by the frustration parameter introduced by Arbeiter and Fennel [New J. Phys. 13, 053022 (2011)].

12.
Eur Arch Otorhinolaryngol ; 276(12): 3281-3286, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520164

RESUMO

OBJECTIVE: Electroneurography (ENoG) reliably predicts the prognosis of facial palsy. However, the results of ENoG are dependent on the location, where the wave is detected, as a compound muscle action potential (CMAP) arising from the facial muscles. To minimize errors in prognostic prediction, we analysed the latencies of facial CMAPs. MATERIALS AND METHODS: Fifty-seven patients with unilateral peripheral facial palsy and 24 healthy volunteers were enrolled. Amplitudes, negative peak latencies (NPL), and rise latencies (RL) of CMAPs were measured on the paralysed and healthy sides in patients and in healthy volunteers. The relationships of these latencies with ENoG values and the lowest House-Brackmann (H-B) scores were also analysed. RESULTS: The amplitude of CMAP on the paralysed side was smaller, and NPL and RL were longer, than those on the healthy side in patients and healthy volunteers (p < 0.01). In patients, there was no difference in NPL between the ENoG < 40% group and the ENoG ≥ 40% group. Conversely, there was a significant difference in RL between the ENoG < 40% group and ENoG ≥ 40% group (p = 0.03). No relationships were observed between NPL or RL and the lowest H-B score. CONCLUSIONS: NPL and RL of CMAP on the paralysed side were equivalent or longer than those on the healthy side. During ENoG for facial palsy, CMAP should be measured on the healthy side first, and then detected (and the amplitude measured) on the paralysed side with reference to CMAP latency on the healthy side, to reduce errors in detecting facial CMAPs.


Assuntos
Potenciais de Ação/fisiologia , Paralisia de Bell/diagnóstico , Paralisia de Bell/fisiopatologia , Músculos Faciais/fisiopatologia , Nervo Facial/fisiopatologia , Paralisia Facial/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estimulação Elétrica , Eletrodiagnóstico/instrumentação , Eletrodiagnóstico/métodos , Face , Músculos Faciais/inervação , Paralisia Facial/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
13.
J Stroke Cerebrovasc Dis ; 28(6): 1691-1702, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30898444

RESUMO

BACKGROUND: Data on the clinical and radiological characteristics of intracranial artery dissection (IAD) have remained limited. Our purpose was to reveal the clinical and radiological characteristics of IAD according to diagnostic criteria for IAD as recently reported by a group of international experts. METHODS: Patients were retrospectively enrolled using a prospective single-center stroke registry between 2011 and 2016. Baseline characteristics and radiological findings including conventional magnetic resonance imaging (MRI) sequences, magnetic resonance angiography (MRA), high-resolution 3-dimensional T1-weighted imaging (HR-3D-T1WI), and digital subtraction angiography were reviewed. We performed statistical comparisons to determine which findings from which modalities are useful. RESULTS: We identified 118 patients with suspected artery dissection, with 64 patients (median age, 51 [interquartile range, 45-56) years; 16 women) finally meeting the criteria for definite (n = 47), probable (n = 15), or possible (n = 2) idiopathic IAD. Ischemic stroke alone was found in 31 patients (48%) on admission. There were 36 patients (56%) suffering from hypertension and 39 (61%) with smoking history. The vertebral artery alone was the most affected in 42 patients (66%). Intramural hematoma (IMH) was more frequently detected on HR-3D-T1WI than on conventional MRI/MRA (odds ratio, 4.72; 95% confidence interval, 1.71-13.00). In 54 patients (84%), the modified Rankin Scale score after 3 months was 0-1. CONCLUSIONS: Male dominance and age at IAD onset were similar to previous studies, and more than half had hypertension and smoking history. We confirmed that HR-3D-T1WI is useful for detecting IMH in the diagnostic criteria.


Assuntos
Angiografia Digital , Dissecção Aórtica/diagnóstico por imagem , Angiografia Cerebral/métodos , Imagem de Difusão por Ressonância Magnética , Aneurisma Intracraniano/diagnóstico por imagem , Angiografia por Ressonância Magnética , Idade de Início , Dissecção Aórtica/etiologia , Avaliação da Deficiência , Feminino , Humanos , Hipertensão/complicações , Aneurisma Intracraniano/etiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos
14.
J Stroke Cerebrovasc Dis ; 28(8): 2201-2206, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31122713

RESUMO

BACKGROUND: The purpose of this study was to assess whether carotid ultrasonography indices detect arterial stenosis progression in patients with vertebral artery (VA) dissection. METHODS: This was a retrospective, single-center, observational study that enrolled patients with intracranial VA dissection who were admitted from January 2011 to June 2017. Magnetic resonance angiography (MRA) was done on admission and followed up at a median 20 days after onset (interquartile range [IQR] 9-58 days), and ultrasonography was performed at a median of 22 (interquartile range 7-56) days. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), and pulsatility index (PI) were measured by ultrasonography, and the ratio of each follow-up value to the baseline (follow-up/baseline) value was calculated. Two stroke neurologists categorized into 3 groups by morphological changes of the dissected vessel: patients with stenosis progression (progression group: P-group); those with no remarkable change or dilatation improved (stable group: S-group); and those with stenosis regression or dilatation enlargement (enlargement group: E-group). Ultrasonography indices were compared among the groups. RESULTS: Of the 42 patients who were enrolled to this study, 39 patients underwent ultrasonography and MRA on both admission and follow-up. The PI ratio was significantly higher in the P-group than in the S-group (1.96 ± .80 versus .98 ± .44, P = .02) and in the E-group (versus .65 ± .35, P < .01). There were no significant differences in the PSV ratio, EDV ratio, and MV ratio. CONCLUSIONS: In patients with VA dissection, the PI ratio on ultrasonography is a promising index to detect stenosis progression.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Ultrassonografia/métodos , Dissecação da Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/diagnóstico por imagem , Adulto , Velocidade do Fluxo Sanguíneo , Artérias Carótidas/fisiopatologia , Angiografia Cerebral/métodos , Circulação Cerebrovascular , Constrição Patológica , Progressão da Doença , Feminino , Humanos , Japão , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fluxo Pulsátil , Sistema de Registros , Estudos Retrospectivos , Índice de Gravidade de Doença , Artéria Vertebral/fisiopatologia , Dissecação da Artéria Vertebral/fisiopatologia
15.
Phys Rev Lett ; 120(22): 223201, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29906148

RESUMO

We show that electron and ion spectroscopy reveals the details of the oligomer formation in Ar clusters exposed to an x-ray free electron laser (XFEL) pulse, i.e., chemical dynamics triggered by x rays. With guidance from a dedicated molecular dynamics simulation tool, we find that van der Waals bonding, the oligomer formation mechanism, and charge transfer among the cluster constituents significantly affect ionization dynamics induced by an XFEL pulse of moderate fluence. Our results clearly demonstrate that XFEL pulses can be used not only to "damage and destroy" molecular assemblies but also to modify and transform their molecular structure. The accuracy of the predictions obtained makes it possible to apply the cluster spectroscopy, in connection with the respective simulations, for estimation of the XFEL pulse fluence in the fluence regime below single-atom multiple-photon absorption, which is hardly accessible with other diagnostic tools.

16.
Cerebrovasc Dis ; 45(5-6): 258-262, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29879697

RESUMO

BACKGROUND AND PURPOSE: The dynamic displacement of the carotid arteries with interference of the hyoid bone during swallowing, named as "flip-flop" phenomenon (FFP), may be associated with ischemic stroke. However, the extent to which FFP is prevalent in carotid artery disease remains unknown. We aimed to investigate its exact prevalence to explore the relationship between FFP and carotid artery disease. METHODS: We examined 202 consecutive patients who were affected by neurological diseases including cerebrovascular diseases. Using carotid ultrasound, we evaluated carotid intima-media thickness, internal carotid artery stenosis (ICS), and FFP during swallowing with neck rotation. RESULTS: FFP was observed in 39 of the 202 patients (19.3%). Patients with FFP showed significantly higher prevalence of ICS than those without FFP (12/39 [30.8] vs. 21/163 [12.9%]; p = 0.007). Among those with ICS (n = 33; 36 vessels), FFP was associated with symptomatic ICS more frequently than with asymptomatic ICS (6/11 [54.5] vs. 5/25 [20.0%]; p = 0.038). Among those with unilateral FFP (n = 37), the prevalence of ipsilateral ICS was higher than that of contralateral ICS (9/37 [24.3] vs. 2/37 [5.4%]; p = 0.035). CONCLUSIONS: FFP accompanies the swallowing movement in some neurological patients, and more frequently in patients with ICS. FFP may thus be a novel indicator of stroke.


Assuntos
Artéria Carótida Externa/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Espessura Intima-Media Carotídea , Estenose das Carótidas/diagnóstico por imagem , Deglutição , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos , Estenose das Carótidas/epidemiologia , Estenose das Carótidas/fisiopatologia , Feminino , Movimentos da Cabeça , Humanos , Osso Hioide/diagnóstico por imagem , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Rotação , Fatores de Tempo
17.
Circ J ; 82(11): 2872-2879, 2018 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-30210082

RESUMO

BACKGROUND: Measuring anti-Xa activity (AXA) has been reported as useful for predicting future risk of hemorrhagic and ischemic events in stroke patients taking direct factor Xa inhibitors. We evaluated AXA levels of rivaroxaban or apixaban in acute stroke patients with non-valvular atrial fibrillation. Methods and Results: This was a single-center, prospective, observational study. Consecutive patients with acute ischemic stroke or transient ischemic attack who were admitted within 7 days of onset and started taking rivaroxaban or apixaban for NVAF between January 2012 and April 2017 were enrolled. AXA was measured at 2 time points: just before (AXAtrough) and 4 h after (AXApeak) taking rivaroxaban or apixaban on the 2nd day or later of administration. Of 156 patients taking rivaroxaban, hemorrhagic events occurred in 13. Patients with hemorrhagic events had higher AXApeak than those without [median (interquartile range): 1.93 (1.11-3.75) vs. 1.35 (0.80-2.00) IU/mL; P<0.01]. Multivariable-adjusted Cox models showed that AXApeak was independently related to the incidence of hemorrhagic events. Of 169 patients taking apixaban, hemorrhagic events occurred in 11. Patients with hemorrhagic events had higher AXAtrough [2.78 (1.90-3.53) vs. 1.42 (0.93-2.08) IU/mL, P<0.01] and AXApeak [4.05 (3.44-4.72) vs. 2.43 (1.79-3.35) IU/mL, P<0.01] than those without. Both AXAtrough and AXApeak were independently related to the incidence of hemorrhagic events. CONCLUSIONS: In these patients who started rivaroxaban or apixaban early after stroke, AXA levels in the early period were related to future hemorrhagic events.


Assuntos
Isquemia Encefálica , Hemorragia Cerebral , Inibidores do Fator Xa/sangue , Pirazóis/administração & dosagem , Piridonas/administração & dosagem , Sistema de Registros , Rivaroxabana/administração & dosagem , Acidente Vascular Cerebral , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/sangue , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/epidemiologia , Hemorragia Cerebral/sangue , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/epidemiologia , Humanos , Incidência , Estudos Prospectivos , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/epidemiologia
18.
J Stroke Cerebrovasc Dis ; 27(6): 1552-1555, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29402615

RESUMO

BACKGROUND: Identification of stroke signs by emergency medical technicians (EMTs) is important for initiating the "stroke chain of survival." The aim of the present study was to clarify the effect of EMT-led lessons on stroke awareness for schoolchildren in the Akashi project on the transportation time to arrive at the hospital. METHODS: Stroke lessons were given by EMTs to 887 elementary school children in elementary schools between September 2014 and October 2015. Data on transportation times from prehospital records and final diagnoses at discharge were collected from both pre- (period 1; January-June 2014) and posteducation (period 2; January-June 2016) periods. Transportation time or onset-to-door time was divided into two parts: the onset-to-call time and the call-to-door time. RESULTS: One hundred forty-four patients in period 1 and 143 in period 2 were transported with potential strokes identified by EMTs. Among these, 119 (83%) in period 1 and 114 (80%) in period 2 had final diagnosis of stroke or transient ischemic attack. The mean age in period 2 was older than that in period 1 (75 years old versus 72 years old); however, there were no significant differences in gender and consciousness level between the 2 periods. The median call-to-door time of 28 minutes for period-2 patients was significantly shorter than that for period-1 patients (32 minutes, P = .0057). There were no differences in median onset-to-door times and onset-to-call times between the 2 periods. CONCLUSIONS: School-based education about stroke conducted by EMTs may be a promising strategy to cut the prehospital delay and to widely spread stroke awareness via school children and EMTs.


Assuntos
Serviços Médicos de Emergência/organização & administração , Auxiliares de Emergência/organização & administração , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Ataque Isquêmico Transitório/terapia , Acidente Vascular Cerebral/terapia , Estudantes/psicologia , Tempo para o Tratamento/organização & administração , Transporte de Pacientes/organização & administração , Idoso , Idoso de 80 Anos ou mais , Criança , Comportamento Infantil , Procedimentos Clínicos , Feminino , Humanos , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/diagnóstico , Ataque Isquêmico Transitório/fisiopatologia , Japão , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Telefone , Fatores de Tempo , Resultado do Tratamento
19.
J Stroke Cerebrovasc Dis ; 27(7): 1810-1814, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29544681

RESUMO

BACKGROUND: Advancing school-based education is a promising means to spread knowledge pertaining to stroke. The aim of the current study was to clarify whether stroke lessons provided by schoolteachers could deliver stroke knowledge to children (aged 9-11 years) and their parents, at a similar level to when taught by medical staff. METHODS: Schoolteachers conducted lessons on stroke for school children using the educational materials we prepared (i.e., the teacher group; 1051 children and 719 parents). This was compared with our previous data from Akashi city and Tochigi prefecture, in which the stroke lessons were conducted by medical staff (i.e., the medical group; 1031 children and 756 parents). Three campaigns were conducted between September 2014 and May 2016. Each child was given education materials to take home to discuss stroke with their parents. The children and their parents answered questionnaires on stroke knowledge, at baseline, immediately after the lesson, and at 3 months after the lesson. RESULTS: Compared with the time point before the lesson, both children and parents instructed by the teacher group showed significant increases in the scores about stroke symptoms and risk factors, immediately and at 3 months after the lesson (P < .001). The combined analysis for the group instructed by medical personnel showed no significant differences in the stroke knowledge scores between the 2 groups at 3 months. CONCLUSIONS: Teacher-led lessons, using our educational material, adequately delivered knowledge of stroke to children and parents, in a manner that was similar to when medical staff delivered this information.


Assuntos
Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Instituições Acadêmicas , Acidente Vascular Cerebral , Estudantes , Conscientização , Criança , Estudos Transversais , Educação em Saúde/métodos , Humanos , Pais , Professores Escolares , Estudantes/psicologia , Inquéritos e Questionários , Materiais de Ensino
20.
Phys Chem Chem Phys ; 19(30): 19707-19721, 2017 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-28530728

RESUMO

Coulomb explosion of diiodomethane CH2I2 molecules irradiated by ultrashort and intense X-ray pulses from SACLA, the Japanese X-ray free electron laser facility, was investigated by multi-ion coincidence measurements and self-consistent charge density-functional-based tight-binding (SCC-DFTB) simulations. The diiodomethane molecule, containing two heavy-atom X-ray absorbing sites, exhibits a rather different charge generation and nuclear motion dynamics compared to iodomethane CH3I with only a single heavy atom, as studied earlier. We focus on charge creation and distribution in CH2I2 in comparison to CH3I. The release of kinetic energy into atomic ion fragments is also studied by comparing SCC-DFTB simulations with the experiment. Compared to earlier simulations, several key enhancements are made, such as the introduction of a bond axis recoil model, where vibrational energy generated during charge creation processes induces only bond stretching or shrinking. We also propose an analytical Coulomb energy partition model to extract the essential mechanism of Coulomb explosion of molecules from the computed and the experimentally measured kinetic energies of fragment atomic ions by partitioning each pair Coulomb interaction energy into two ions of the pair under the constraint of momentum conservation. Effective internuclear distances assigned to individual fragment ions at the critical moment of the Coulomb explosion are then estimated from the average kinetic energies of the ions. We demonstrate, with good agreement between the experiment and the SCC-DFTB simulation, how the more heavily charged iodine fragments and their interplay define the characteristic features of the Coulomb explosion of CH2I2. The present study also confirms earlier findings concerning the magnitude of bond elongation in the ultrashort X-ray pulse duration, showing that structural damage to all but C-H bonds does not develop to a noticeable degree in the pulse length of ∼10 fs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA