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1.
Turk J Med Sci ; 53(3): 824-834, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37476895

RESUMO

BACKGROUND: To investigate the possible relationship between pectoralis muscle (PM) measurement and frailty in older women with breast cancer (BC) (preoperatively defined as stage 1, 2, and 3 diseases). METHODS: This retrospective, observational study was conducted at Konya Training and Research Hospital between June and December 2020. A total of 102 patients [median age 62.5 years, median follow-up period two years] were included in the study. PM measurements were obtained from thorax computerized tomography (CT). Pectoralis muscle index (PMI) was calculated by dividing the PM area by the height square of the patients (cm2/m2). Pectoralis muscle density (PMD) was evaluated using CT findings, including their Hounsfield Units (HU). Frailty status and sarcopenia-risk assessments were done by a telephone interview in September 2020 using the FRAIL index (categorized as robust or nonrobust) and SARC-F questionnaire (classified as no sarcopenia-risk or risk of sarcopenia), respectively. PM measurements were compared between robust and nonrobust patients and between patients with a risk of sarcopenia and no sarcopenia risk. RESULTS: The nonrobust patients had lower pectoralis major muscle index (PMaMI) (p = 0.041) and pectoralis major muscle density(PMaD) (p = 0.020) levels than robust patients in the whole study sample. PMI (p = 0.017) and PMaMI (p = 0.010) levels were significantly lower in the nonrobust patients than in robust patients with early-stage BC. Frailty status was positively correlated with age (rho: 0.621; p < 0.001), BC stage (rho: 0.220; p = 0.026), and SARC-F score (rho: 0.747; p < 0.001), and negatively correlated with PMaMI (rho: -0.197; p = 0.047) and PMaD (rho: -0.237; p = 0.016). There were significant associations between PMaMI (OR: 0.467, 95% Confidence Interval (CI): 0.226-0.962 p = 0.039) and PMI (OR: 0.543, 95% CI: 0.299-0.986 p = 0.045) levels with frailty status (being nonrobust) in regression models. DISCUSSION: In the study, it has been shown that pectoralis muscle assessment might be a related parameter to frailty in older women with breast cancer.


Assuntos
Neoplasias da Mama , Fragilidade , Sarcopenia , Humanos , Feminino , Idoso , Pessoa de Meia-Idade , Fragilidade/epidemiologia , Músculos Peitorais/diagnóstico por imagem , Neoplasias da Mama/complicações , Neoplasias da Mama/epidemiologia , Idoso Fragilizado , Estudos Retrospectivos , Sarcopenia/epidemiologia
2.
Ann Noninvasive Electrocardiol ; 23(5): e12558, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29873439

RESUMO

BACKGROUND: To our knowledge, no study so far investigated the importance of post-procedural frontal QRS-T angle f(QRS-T) in ST segment elevation myocardial infarction (STEMI). The aim of our study was to investigate the role of baseline and post-procedural f(QRS-T) angles for determining high risk STEMI patients, and the success of reperfusion. METHODS: A total of 248 patients with first acute STEMI that underwent primary percutaneous coronary intervention (pPCI) or thrombolytic therapy (TT) between 2013 and 2014 were included in this study. Baseline f(QRS-T) angle was defined as the angle which measured from the first ECG at the time of hospital admission. Post-procedural (QRS-T) angle was defined according to the treatment strategy as follows: the angle which measured from the post-PCI ECG in patients treated with pPCI; the angle which measured from the ECG taken 90 min after onset of therapy in patients treated with TT. RESULTS: The baseline (101.9° ± 48.0 vs. 72.1° ± 49.1, p = 0.014) and post-procedural f(QRS-T) angles (95.7° ± 48.1 vs. 58.1° ± 47.1, p = 0.002) were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality. Also, f(QRS-T) angle measured at 90 min was significantly lower in patients with successful thrombolysis group compared to failed thrombolysis group (53.2° ± 42.8 vs. 77.3° ± 52.9, p = 0.033), whereas baseline f(QRS-T) angle was similar between two groups (78.6° ± 53.4 vs. 78.9° ± 54.0, p = 0.976). Multivariate analysis showed that post-procedural f(QRS-T) angle ≥89.6° (odds ratio: 3.541, 95% confidence interval: 1.235-10.154, p = 0.019), but not baseline f(QRS-T) angle, was independent predictor of in-hospital mortality. CONCLUSION: f(QRS-T) angle may be used as a beneficial tool for determining high risk patients in acute STEMI. Unlike previous studies, we showed for the first time that that post-procedural f(QRS-T) can predict in-hospital mortality and TT failure.


Assuntos
Eletrocardiografia/métodos , Intervenção Coronária Percutânea/métodos , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Terapia Trombolítica/métodos , Angiografia Coronária/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem
3.
Clin Exp Hypertens ; 40(4): 318-323, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28949780

RESUMO

BACKGROUND: Frontal QRS-T angle is a novel marker of myocardial repolarization, and an increased frontal QRS-T angle associated with adverse cardiac outcomes. Non-dipper hypertension is also associated with adverse cardiac outcomes. This study aimed to investigate the relationship between frontal QRS-T angle and non-dipper status in hypertensive patients without left ventricular hypertrophy (LVH). METHODS: This study included 122 hypertensive patients without LVH. Patients were divided into two groups: dipper hypertension and non-dipper hypertension. The frontal QRS-T angle was calculated from 12-lead electrocardiography. RESULTS: Frontal QRS-T angle (47.9° ± 29.7° vs. 26.7° ± 19.6°, P < 0.001) was significantly higher in patients with non-dipper hypertension than in patients with dipper hypertension. In addition, frontal QRS-T angle was positively correlated with sleeping systolic (r = 0.211, P = 0.020), and diastolic (r = 0.199, P = 0.028) blood pressures (BP), even if they were weak. Multivariate analysis showed that the frontal QRS-T angle was independent predictor of non-dipper status (QR: 1.037, 95% CI: 1.019-1.056, P < 0.001). CONCLUSION: Frontal QRS-T angle is independent predictor of non-dipper status in hypertensive patients without LVH.


Assuntos
Pressão Sanguínea , Ritmo Circadiano/fisiologia , Coração/fisiopatologia , Hipertensão/fisiopatologia , Adulto , Idoso , Diástole , Eletrocardiografia , Feminino , Humanos , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , Sono/fisiologia , Sístole
4.
J Electrocardiol ; 51(2): 210-217, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29117907

RESUMO

BACKGROUND: No study has investigated the prognostic importance of the combined use of QRS distortion and fragmented QRS (fQRS) for risk stratification in acute ST segment elevation myocardial infarction (STEMI). OBJECTIVE: To determine the prognostic value of the combined use of QRS distortion and fQRS in patients with acute STEMI undergoing primary percutaneous coronary intervention (pPCI). METHODS: A total of 454 patients with first STEMI who underwent pPCI were included in this study. Patients were categorized into three groups according to the presence of QRS distortion and fQRS on admission electrocardiography. Group I was defined as fQRS (-) and QRS distortion (-), group 2 was defined as fQRS (+) and QRS distortion (-), or fQRS (-) and QRS distortion (+), and group 3 was defined as both fQRS (+) and QRS distortion (+). RESULTS: Patients in group III had a significantly higher in-hospital mortality rate compared with patients in groups I and II. These patients also had lower left ventricular ejection fraction and ST resolution ratios, higher maximum troponin, and higher frequency of three-vessel disease. Multivariate analysis indicated that group III (OR: 8.84, 95% CI: 2.73-28.62, p<0.001) was an independent predictors of in-hospital mortality. CONCLUSION: The combined use of QRS distortion and fQRS provides additional prognostic value compared with the presence of QRS distortion or fQRS alone for early risk stratification in patients with STEMI treated with pPCI.


Assuntos
Eletrocardiografia , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Biomarcadores/sangue , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Medição de Risco , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade
5.
Ann Noninvasive Electrocardiol ; 20(6): 578-85, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25640307

RESUMO

BACKGROUND: QRS fragmentation (fQRS) and QRS distortion were separately shown to be related to increased cardiovascular mortality and morbidity. To our knowledge, no study so far evaluated both parameters together in ST segment elevation myocardial infarction (STEMI). The main goal of our study is to find out if fQRS and QRS distortion can help us to determine high-risk STEMI patients, and the success of reperfusion. METHODS: Two hundred forty-eight eligible patients with acute STEMI that underwent coronary angiography consecutively between January 1, 2009, and July 1, 2011, were enrolled in this study. Twelve-lead electrocardiography (ECG) of the patients taken in the first 48 hours were analyzed. Patients with fQRS formed group 1, without fQRS formed group 2; with QRS distortion formed group 3, and without QRS distortion formed group 4. RESULTS: Group 1 have lower left ventricular ejection fraction (LVEF; P < 0.001), higher maximum troponin levels (P < 0.001), lower ST segment resolution (P < 0.001), more frequent proximal lesions (P < 0.001) when compared to group 2. Similar findings were observed in group 3 in comparison to group 4. Group 1 had also more frequent three vessels disease (P < 0.001), and higher rates of failed thrombolysis (P < 0.001). In-hospital mortality was found to be higher in group 1 and group 3. CONCLUSION: fQRS and QRS distortion may be useful for identifying patients at higher cardiac risk. fQRS can foresee thrombolytic therapy failure and three vessels disease whereas QRS distortion does not possess such quality. These findings may guide the physician deciding initial treatment modality in STEMI.


Assuntos
Eletrocardiografia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/terapia , Intervenção Coronária Percutânea , Terapia Trombolítica , Idoso , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica , Valor Preditivo dos Testes , Estudos Retrospectivos , Risco
6.
Langmuir ; 30(41): 12391-9, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25263163

RESUMO

The fabrication of micrometer-sized core-shell particles for ultrasound-triggered delivery offers a variety of applications in medical research. In this work, we report the design and development of a glass capillary microfluidic system containing three concentric glass capillary tubes for the development of core-shell particles. The setup enables the preparation of perfluorocarbon-alginate core-shell microspheres in a single process, avoiding the requirement for further extensive purification steps. Core-shell microspheres in the range of 110-130 µm are prepared and are demonstrated to be stable up to 21 days upon immersion in calcium chloride solution or water. The mechanical stability of the particles is tested by injecting them through a 23 gauge needle into a polyacrylamide gel to mimic the tissue matrix. The integrity of the particles is maintained after the injection process and is disrupted after ultrasound exposure for 15 min. The results suggest that the perfluorcarbon-alginate microparticles could be a promising system for the delivery of compounds, such as proteins, peptides, and small-molecule drugs in ultrasound-based therapies.


Assuntos
Alginatos/síntese química , Fluorocarbonos/síntese química , Técnicas Analíticas Microfluídicas , Microesferas , Terapia por Ultrassom , Alginatos/química , Fluorocarbonos/química , Tamanho da Partícula , Propriedades de Superfície
7.
Proc Natl Acad Sci U S A ; 108(3): 989-94, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21097706

RESUMO

Deposition of metals on binary alloy surfaces offers new possibilities for guiding the formation of functional metal nanostructures. This idea is explored with scanning tunneling microscopy studies and atomistic-level analysis and modeling of nonequilibrium island formation. For Au/NiAl(110), complex monolayer structures are found and compared with the simple fcc(110) bilayer structure recently observed for Ag/NiAl(110). We also consider a more complex codeposition system, (Ni + Al)/NiAl(110), which offers the opportunity for fundamental studies of self-growth of alloys including deviations for equilibrium ordering. A general multisite lattice-gas model framework enables analysis of structure selection and morphological evolution in these systems.


Assuntos
Ligas/química , Alumínio/química , Físico-Química/métodos , Ouro/química , Modelos Químicos , Nanoestruturas/química , Níquel/química , Prata/química , Adsorção , Propriedades de Superfície
8.
Phys Rev Lett ; 108(21): 216102, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-23003283

RESUMO

The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment of surface diffusion kinetics. Simultaneous codeposition with 3:1 Ni:Al yields poor ordering at 300 K but well-ordered structures by ~500 K. Sequential codeposition of Ni then Al yields unmixed core-ring nanostructures at 300 K but strong intermixing and ordering by ~500 K.

9.
J Chem Phys ; 135(8): 084706, 2011 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-21895213

RESUMO

Scanning tunneling microscopy studies reveal that two-dimensional nanoscale Ni islands formed by deposition of Ni on NiAl(110) between 200-400 K exhibit far-from-equilibrium growth shapes which change systematically with temperature. Island structure reflects the two types of adsorption sites available for Ni adatoms, and island shapes are controlled by the details of adatom diffusion along island edges accounting for numerous local configurations. The temperature dependence of the island shapes is captured and elucidated by kinetic Monte Carlo simulation of a realistic atomistic-level multisite lattice-gas model incorporating precise diffusion barriers. These barriers are obtained by utilizing density functional theory to probe energetics not just at adsorption sites but also at transition states for diffusion. This success demonstrates a capability for predictive atomistic-level modeling of nanocluster formation and shape selection in systems that have a high level of energetic and kinetic complexity.

10.
Mil Med ; 186(Suppl 1): 716-721, 2021 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-33499548

RESUMO

INTRODUCTION: We developed low-cost, portable paper-based diagnostic devices for detection of human immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum without any sample preparation. These devices can be used to help identify presence of diseases, used to provide rapid results (<5 minutes), readily used by untrained personnel, employed in austere environments, configured to obtain multiplexed assays, and easily disposed of. MATERIALS AND METHODS: We successfully accomplished colorimetric detection of human IgG and human IgM using a sandwich-style assay within the microfluidic paper device via vertical flow immunoassay configuration. The reaction zone in the wax printed paper layer is a small circular pattern. Gold nanoparticles conjugated with anti-human IgG and IgM antibodies have been used for colorimetric detection of IgG or IgM by naked eye. Colorimetric signal can be precisely quantified through implementation of image analysis software which can be developed as an app for a smartphone. The size of the device is 2 cm × 2 cm × 1 mm. RESULTS: Colorimetric detection of human IgG was accomplished at 100 fg/mL concentration using a gold nanoparticle-conjugated anti-human IgG antibody. The developed platform has a dynamic range of IgM and IgG concentrations between 0.1 pg/mL and 100 µg/mL. These devices provided a color readout in <5 minutes using 20 µL of serum. We also demonstrated that the devices show a significant degree of ruggedness and temperature stability as they were able to provide satisfactory results (detection of 0.1 pg/mL IgG) after 14 days of long stability and shelf-life experiment at an elevated temperature of at least 50 ˚C-the shelf life can be as long as 180 days under ambient conditions for detection of 100 µg/mL IgG. CONCLUSIONS: Because of the inherent simplicity of the device operation and their ease of use, there is no variation between samples and users of the device. This low-cost approach enables multiplexing with >1 measurement performed in parallel at the same time. We anticipate that because of the sensitivity, specificity, ease of use, and overall reliability, this approach will become a standard for diagnosis of diseases and health conditions.


Assuntos
Microfluídica , Ouro , Humanos , Imunoensaio , Nanopartículas Metálicas , Reprodutibilidade dos Testes
11.
Lab Chip ; 21(17): 3289-3297, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34612459

RESUMO

Tacrolimus is one of the most effective and prevalent drugs used to combat vascularized composite allotransplantation rejection. We have fabricated a rapid and easy-to-use six-layer paper based microfluidic device using the principles of competitive immunoassays and vertical flow microfluidics for colorimetric detection of tacrolimus in a small volume of blood.


Assuntos
Técnicas Biossensoriais , Alotransplante de Tecidos Compostos Vascularizados , Monitoramento de Medicamentos , Rejeição de Enxerto , Tacrolimo
12.
Turk Kardiyol Dern Ars ; 49(8): 606-614, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34881698

RESUMO

OBJECTIVE: To assess the effects of transvalvular aortic valve implantation (TAVI) on the outcomes of the patients with symptomatic severe aortic stenosis (AS), and predict the effect of left ventricular ejection fraction (LVEF) and cardiac structural recovery on mortality after the TAVI in patients with different stage of LV function. METHODS: Out of 191 patients, 151 consecutive patients in 3 centers were evaluated for outcome analysis. Patients were classified into 3 subgroups as AS with reduced ejection fraction (ASrEF) (LVEF <40%), AS with mildly reduced EF (ASmrEF) (LVEF 40-49%) and AS with preserved EF (ASpEF) (LVEF ≥50%). RESULTS: The mean follow-up period was 19.4±12.4 (up to 54) months. All-cause mortality was not different among all 3 groups. (p=0.901). In multivariate analysis, stroke volume index (SVI) (Exp(B): 0.039, 95% confidence interval [CI]: 0.011-0.013, p<0.001), baseline blood urea nitrogen (Exp(B): 1.022, 95% CI: 1.006-1.038, p=0.006), and percent LVEF change after TAVI (d-LVEF) (Exp(B): 0.046, 95% CI: 0.004-0.610, p=0.046) were the independent predictors for mortality after TAVI. The receiver operating characteristic curve analysis showed that the cutoff value of "≤10%" for d-LVEF had sensitivity of 50%, specificity of 75%, and an area under the curve of 0.72 in predicting mortality in patients with SVI <35 mL/m2. CONCLUSION: Improvement of LVEF after TAVI, which reflected the marked LV reverse remodeling, has an impact on the prediction of the survival in patients with AS, and this is more prominent in patients with low SVI.


Assuntos
Estenose da Valva Aórtica/mortalidade , Estenose da Valva Aórtica/cirurgia , Volume Sistólico/fisiologia , Substituição da Valva Aórtica Transcateter/mortalidade , Função Ventricular Esquerda/fisiologia , Idoso , Estenose da Valva Aórtica/classificação , Nitrogênio da Ureia Sanguínea , Causas de Morte , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Análise Multivariada , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento , Disfunção Ventricular Esquerda/fisiopatologia
13.
Eur J Gastroenterol Hepatol ; 33(11): 1441-1450, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33741802

RESUMO

BACKGROUND: Cirrhotic cardiomyopathy (CCM) is a well-known entity. The aim of this study was to compare left atrial three-dimensional (3D) volume and P-wave dispersion (PWd) in patients with cirrhosis and a healthy population. The secondary purpose was to assess the left phasic volumes and reservoir functions with 3D echocardiography for the prediction of an increased risk of poor outcomes in patients with cirrhosis. METHODS: The study included 50 patients with cirrhosis and 43 healthy control subjects without atrial fibrillation. All patients were assessed with two-dimensional (2D), 3D, and tissue Doppler transthoracic echocardiography. The PWd was calculated using a 12-lead surface electrocardiogram (ECG). Cirrhotic patients were followed up for 2.5 years for the evaluation of poor outcomes and the development of atrial fibrillation. RESULTS: Patients with cirrhosis were observed to have significantly higher left atrial phasic volumes such as minimal left atrial volume (3D-LAVmin, P = 0.004) and indexed LAVmin (3D-LAVImin, P = 0.0001), and significantly decreased left atrial reservoir functions such as left atrial emptying volume (3D-LAEV, P = 0,001), left atrial ejection fraction (3D-LAEF, P = 0,001) on 3D echocardiography. PWd was determined to be significantly longer in the cirrhotic group compared with the control group (P = 0.003). In the 2.5-year follow-up period, poor outcomes occurred in 34 patients (22 patients died, six patients had liver transplantation, six patients developed atrial fibrillation/AHRE episodes). In Cox regression analysis, the MELD score (HR, 1.16 (1.06-1.26), P = 0.001) and 3D-LAVImin (HR, 0.95 (0.86-1.00), P = 0.040) were significantly associated with all-cause mortality. Cirrhotic patients with LAVImin of >15 ml/m2 were seen to have poor survival (long rank P = 0.033). CONCLUSION: The results of this study showed that patients with cirrhosis had higher left atrial volume, longer PWd and worse diastolic functions compared with the control group. Higher disease severity scores were associated with left atrial function and volume. In addition, left atrial volume measured with 3DE was a strong predictor of future adverse events, and minimal left atrial volumes had a higher prognostic value than any other left atrial function indices.


Assuntos
Função do Átrio Esquerdo , Ecocardiografia Tridimensional , Átrios do Coração/diagnóstico por imagem , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico por imagem , Prognóstico
14.
Acta Cardiol ; 76(5): 475-485, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33146076

RESUMO

AIMS: The objective of this study is to assess the prognostic effects of T ranscatheter aortic valve replacement (TAVR) on the patients with different degrees of left ventricular systolic (LVS) function and severe symptomatic aortic stenosis. Also examines the prognostic association of LV remodelling after TAVR. METHODS AND RESULTS: Patients stratified into four subgroups with respect to baseline LV ejection fraction (LVEF) (LVEF > 25%, LVEF 25%-40%, LVEF 41%-49% and LVEF ≥ 50%). We compared the baseline characteristics and temporal changes in echocardiographic parameters of the patients after TAVR, and determined all-cause mortality (ACM) in a follow-up period of mean 20.7 ± 15.8 months (up to 84). There were 495 patients at 8 centres. ACM was similar in all groups (28.1%, 29.5%, 22.5% and 24.1% respectively; p = .44). Immediately after TAVR, there was an improvement in LVEF (from 38.7 ± 9.4 to 44.9% ± 10.9%, p < .001). The percent change in LVEF (pDelta-EF) immediately after TAVR was more prominent in the patients with LVEF < 25% (48.1 ± 49.6, 21.9 ± 29.6), (8.4% ± 15.2%) and (2.1 ± 7)) (p < .01). Importantly, a 12% increase in absolute Delta-EF was observed in patients with LVEF< 25% with 100% sensitivity and 42.5% specificity for the prediction of ACM. CONCLUSION: This study shows that TAVR is beneficial in the whole range of LVS function, irrespective of the baseline EF. Early recovery in LVEF after TAVR is critical for survival, however, it seems to be more eye catching in the patients with advanced heart failure with reduced EF.


Assuntos
Estenose da Valva Aórtica , Substituição da Valva Aórtica Transcateter , Disfunção Ventricular Esquerda , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Humanos , Estudos Retrospectivos , Volume Sistólico , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnóstico , Função Ventricular Esquerda
15.
J Phys Condens Matter ; 21(5): 055009, 2009 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21817296

RESUMO

From other work, two preferred sites have been suggested for metals and semimetals adsorbed on the fivefold surfaces of icosahedral, Al-based quasicrystals. Because of their appearance in scanning tunneling microscopy (STM) images, these sites are known as dark stars and white flowers. In this paper, we analyze four bulk structural models in physical space to determine the types, chemical decorations, and densities of the dark star-and, to a lesser extent, the white flower-adsorption sites for the fivefold planes of icosahedral Al-Pd-Mn. We find that the chemical decorations of these sites are heterogeneous, even within a single model. Both features are also structurally heterogeneous, according to STM measurements, and the structural variation is consistent with the bulk structure models. Finally, from the models, the density of dark stars in the planes correlates with the step height. This may explain previous experimental observations of different properties for different terraces.

16.
Trends Biotechnol ; 37(6): 563-566, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30851983

RESUMO

Wearable medical devices (WMDs) will advance point-of-care diagnostics and therapeutics. This article analyses the market and patents for wearable devices. Activity monitors have the largest market share, and the intellectual property landscape is dominated by electronics corporations. However, the majority of these patents have not been realized in commercial products.


Assuntos
Tecnologia Biomédica , Monitores de Aptidão Física , Patentes como Assunto , Dispositivos Eletrônicos Vestíveis , Tecnologia Biomédica/economia , Tecnologia Biomédica/instrumentação , Tecnologia Biomédica/legislação & jurisprudência , Monitores de Aptidão Física/economia , Monitores de Aptidão Física/estatística & dados numéricos , Humanos , Dispositivos Eletrônicos Vestíveis/economia , Dispositivos Eletrônicos Vestíveis/estatística & dados numéricos
17.
Adv Healthc Mater ; 8(14): e1900244, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31081270

RESUMO

Lateral flow assays (LFAs) have been the pillar of rapid point-of-care (POC) diagnostics due to their simplicity, rapid process, and low cost. Recent advances in sensitivity, selectivity, and chemical stability enhancement have ensured the foothold of LFAs in commercial POC diagnostics. This paper reviews recent developments in labeling strategies and detection methods of LFAs. Moreover, vertical flow assays (VFAs) have emerged as an alternate paper-based assay due to faster detection time and unique multiplexing capabilities. Smartphones as LFA readers have been transformed into a universal integrated platform for imaging, data processing, and storage, providing quantitative results in low-resource settings. Commercial LFAs and VFAs products are evaluated with regards to their performance, market trends, and regulatory issues. The future outlook of the flow-based assays for POC diagnostics is also discussed.


Assuntos
Bioensaio/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Reologia/métodos , Animais , Humanos , Nanofibras/química , Pontos Quânticos/química , Smartphone
18.
Turk Gogus Kalp Damar Cerrahisi Derg ; 26(1): 65-72, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32082713

RESUMO

BACKGROUND: In this study, we aimed to investigate the effect of transcatheter aortic valve implantation using two types of bioprosthetic valves on novel ventricular repolarization markers including Tp-e, Tp-e/QT and Tpe/QTc ratios, and Tp-ed. METHODS: A total of 61 patients (17 males, 44 females; mean age 78.6±6.5 years; range 55 to 89 years) who underwent transcatheter aortic valve implantation with either a Medtronic CoreValve (n=40) or an Edwards SAPIEN XT valve (n=21) were retrospectively analyzed. The electrocardiographic parameters and left ventricular mass index were calculated prior to the procedure, on postoperative Day 1, and at three months after the procedure. RESULTS: The Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months of the procedure, compared to baseline values (p<0.01, for all). Similar findings were observed for QT, QTc, and QT dispersion (p<0.01, for all). These changes were independent from the types of bioprosthetic valves used. Before the procedure, the left ventricular mass index was positively correlated with the Tp-e (r=0.350, p=0.007), Tp-e/QT (r=0.314, p=0.015) and Tp-e/QTc ratios (r=0.285, p=0.029). In the multivariate analysis, Tp-e interval was found to be independently associated with the left ventricular mass index (b=0.350, p=0.007). CONCLUSION: In the present study, the Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months after transcatheter aortic valve implantation indicating reverse left ventricular remodeling. The effects of two types of bioprosthetic valves on ventricular repolarization markers and left ventricular mass index were similar.

19.
Adv Mater ; : e1706910, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29893068

RESUMO

Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real-time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real-time monitoring of vital signs using biosensors, stimuli-responsive materials for drug delivery, and closed-loop theranostic systems. It covers future challenges in augmented, virtual, and mixed reality, communication modes, energy management, displays, conformity, and data safety. The development of patient-oriented wearable technologies and their incorporation in randomized clinical trials will facilitate the design of safe and effective approaches.

20.
Adv Healthc Mater ; 6(22)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29076283

RESUMO

Paper is used in various applications in biomedical research including diagnostics, separations, and cell cultures. Paper can be conveniently engineered due to its tunable and flexible nature, and is amenable to high-throughput sample preparation and analysis. Paper-based platforms are used to culture primary cells, tumor cells, patient biopsies, stem cells, fibroblasts, osteoblasts, immune cells, bacteria, fungi, and plant cells. These platforms are compatible with standard analytical assays that are typically used to monitor cell behavior. Due to its thickness and porous nature, there are no mass transport limitations to/from the cells in paper scaffolds. It is possible to pattern paper in different scales (micrometer to centimeter), generate modular configurations in 3D, fabricate multicellular and compartmentalized tissue mimetics for clinical applications, and recover cells from the scaffolds for further analysis. 3D paper constructs can provide physiologically relevant tissue models for personalized medicine. Layer-by layer strategies to assemble tissue-like structures from low-cost and biocompatible paper-based materials offer unique opportunities that include understanding fundamental biology, developing disease models, and assembling different tissues for organ-on-paper applications. Paper-based platforms can also be used for origami-inspired tissue engineering. This work provides an overview of recent progress in engineered paper-based biomaterials and platforms to culture and analyze cells.


Assuntos
Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/química , Biomimética/instrumentação , Biomimética/métodos , Humanos , Papel , Alicerces Teciduais/química
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