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1.
Sensors (Basel) ; 22(12)2022 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-35746106

RESUMEN

This paper proposes a displacement sensing method based on magnetic flux measurement. A bridge-structured magnetic circuit, formed by permanent magnets and two ferromagnetic cores, is designed and discussed. The analyses of the equivalent magnetic circuit and three-dimensional finite element simulations showed that the magnetic flux density changes linearly with the reciprocal of the sum of a constant and the displacement. A prototype sensor of the bridge structure is developed that consists of four permanent magnets as excitation, a Hall sensor as reception, and two ferromagnetic cores as the connection. Experiments have validated the feasibility of this method. The measured results show a good linearity between the sensor's output and the reciprocal of the sum of a constant and the displacement, with a correlation coefficient greater than 0.9995 across different measurement ranges. Additionally, the measured results significantly indicate that the proposed sensor is compatible with different ferromagnetic materials with a worst-case error of less than 5%. The proposed sensor has the advantages of low cost and good linearity; however, the test object is limited to ferromagnetic materials.

2.
Opt Express ; 29(23): 37075-37080, 2021 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-34808786

RESUMEN

Quantum key distribution (QKD) using polarisation encoding can be hard to implement over deployed telecom fibres because the routing geometry and the birefringence of the fibre link can alter the polarisation states of the propagating photons. These alterations cause a basis mismatch, leading to an increased quantum bit error rate (QBER). In this work we demonstrate a technique for a dynamically compensating fibre-induced state alteration in a QKD system. This compensation scheme includes a feedback loop that minimizes the QBER using a stochastic optimization algorithm. The effectiveness of this technique is implemented and verified in a polarisation entanglement QKD system over a deployed telecom fibre.

3.
Heart Surg Forum ; 24(5): E893-E897, 2021 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-34730495

RESUMEN

BACKGROUND: Experimental evidence has indicated the benefits of melatonin (Mel) for the treatment of delirium. Clinical trials had no definite conclusions concerning Mel on delirium after percutaneous transluminal coronary intervention (PCI) in elderly patients. The present study explored whether acute Mel treatment could reduce the incidence of delirium. METHODS: This trial enrolled patients over the age of 60, who were admitted to intensive care units (ICUs) after PCI. A computer-generated randomization sequence (in a 1:1 ratio) was used to randomly assign patients to receive Mel (3 mg/day) or placebo once daily for up to 7 days. The primary endpoint was the incidence of delirium, assessed twice daily with the Confusion Assessment Method (CAM) during the first 7 postoperative days. Analyses were performed using intention-to-treat and safety populations. RESULTS: A total of 297 patients randomly were assigned to receive either placebo (N = 149) or Mel (N = 148). The incidence of postoperative delirium was significantly lower in the Mel group than in the placebo group (27.0% vs. 39.6%, respectively, P = 0.02). There was no significant difference between 30-day all-cause mortality (12.2% vs. 14.1%, P = 0.62) and drug reactions (0 vs. 2.0%, P = 0.25). The length of stay and hospitalization costs in the Mel group were significantly decreased compared with those in the placebo group (P > 0.05). CONCLUSION: The current study suggests that Mel is safe and effective in the treatment of delirium after PCI. Further investigation is necessary to fully understand the potential usefulness of Mel in older patients via larger randomized, multicenter, double-blind, and placebo-controlled trials.


Asunto(s)
Delirio/prevención & control , Melatonina/uso terapéutico , Intervención Coronaria Percutánea/efectos adversos , Complicaciones Posoperatorias/prevención & control , Anciano , Unidades de Cuidados Coronarios , Delirio/epidemiología , Delirio/etiología , Método Doble Ciego , Femenino , Humanos , Incidencia , Análisis de Intención de Tratar , Masculino , Persona de Mediana Edad , Placebos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento
4.
Opt Express ; 25(24): 30388-30394, 2017 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-29221068

RESUMEN

Quantum key distribution (QKD) at telecom wavelengths (1260 - 1625 nm) has the potential for fast deployment due to existing optical fibre infrastructure and mature telecom technologies. At these wavelengths, Indium Gallium Arsenide (InGaAs) avalanche photodiode (APD) based detectors are the preferred choice for photon detection. Similar to their Silicon counterparts used at shorter wavelengths, they exhibit fluorescence from recombination of electron-hole pairs generated in the avalanche breakdown process. This fluorescence may open side channels for attacks on QKD systems. Here, we characterize the breakdown fluorescence from two commercial InGaAs single photon counting modules, and find a spectral distribution between 1000 nm and 1600 nm. We also show that by spectral filtering, this side channel can be efficiently suppressed.

5.
Zhonghua Yi Xue Za Zhi ; 93(28): 2205-8, 2013 Jul 23.
Artículo en Zh | MEDLINE | ID: mdl-24169329

RESUMEN

OBJECTIVE: To evaluate the predicative value of serum parathyroid hormone (PTH) levels in outpatients of heart failure (HF) for hospitalization. METHODS: A total of 102 consecutive HF outpatients were enrolled. The receiver operating characteristic (ROC) curves demonstrated the optimal cut-off points of PTH levels for hospitalization due to HF. And Logistic regression analysis model was employed to analyze the independent association between PTH and hospitalization for HF. RESULTS: The more advanced grade of New York Heart Association (NYHA), the higher serum level of PTH. The ROC curves showed PTH levels ≥ 56.05 ng/L were the optimal cut-off point for hospitalization for HF with a sensitivity of 90.0%, a specificity of 89.2% and the area under ROC curve of 0.92. After adjustment for predictors for hospitalization due to HF (gender, age, diabetes mellitus, hypertension, left ventricular ejection fraction, estimated glomerular filtration rate and brain natriuretic peptide), PTH levels were associated with hospitalization due to HF (OR = 1.282, 95%CI 1.026-1.362). CONCLUSION: The serum level of PTH in HF outpatients is an independent predicator for hospitalization due to HF.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Hormona Paratiroidea/sangre , Hospitalización , Humanos , Pacientes Ambulatorios , Curva ROC , Sensibilidad y Especificidad , Función Ventricular Izquierda
6.
Interdiscip Sci ; 15(4): 663-677, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37665496

RESUMEN

Accurate segmentation of medical images is essential for clinical decision-making, and deep learning techniques have shown remarkable results in this area. However, existing segmentation models that combine transformer and convolutional neural networks often use skip connections in U-shaped networks, which may limit their ability to capture contextual information in medical images. To address this limitation, we propose a coordinated mobile and residual transformer UNet (MRC-TransUNet) that combines the strengths of transformer and UNet architectures. Our approach uses a lightweight MR-ViT to address the semantic gap and a reciprocal attention module to compensate for the potential loss of details. To better explore long-range contextual information, we use skip connections only in the first layer and add MR-ViT and RPA modules in the subsequent downsampling layers. In our study, we evaluated the effectiveness of our proposed method on three different medical image segmentation datasets, namely, breast, brain, and lung. Our proposed method outperformed state-of-the-art methods in terms of various evaluation metrics, including the Dice coefficient and Hausdorff distance. These results demonstrate that our proposed method can significantly improve the accuracy of medical image segmentation and has the potential for clinical applications. Illustration of the proposed MRC-TransUNet. For the input medical images, we first subject them to an intrinsic downsampling operation and then replace the original jump connection structure using MR-ViT. The output feature representations at different scales are fused by the RPA module. Finally, an upsampling operation is performed to fuse the features to restore them to the same resolution as the input image.

7.
Biomed Rep ; 12(2): 73-79, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31929877

RESUMEN

Parathyroid hormone (PTH) is a novel cardiovascular biomarker which is particularly useful for detection and assessment of heart failure (HF). However, previous studies examining PTH in heart failure have primarily focused on left HF; thus, the relationship between PTH and right HF remains unclear. The aim of the present study was to evaluate the serum PTH levels in patients with chronic right HF. A total of 154 patients with chronic right HF were enrolled in the present study. A binary logistic regression analysis model was used to assess the independent predictive value of PTH levels in chronic right HF. Partial correlative analysis was used to demonstrate the relevance of PTH levels on the parameters of assessment of right heart function. A multiple linear regression analysis model was used to evaluate the independent factors of PTH levels in patients with right HF. The results showed that the serum PTH levels in the right HF group were significantly higher compared with the control group. After adjusting for predictors of right HF, serum PTH levels were associated with right HF with an odds ratio of 1.066 (95% confidence interval: 1.030-1.102, P<0.001. Serum PTH levels were independently correlated with plasma N-terminal pro-B-type natriuretic peptide levels, right ventricular end-diastolic diameter and severity of lower extremity edema (all P<0.05). Therefore, based on the results of the present study, PTH may be a useful biomarker for detection and assessment of right HF.

8.
Exp Ther Med ; 16(4): 2859-2866, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30214507

RESUMEN

The present study investigated the role of parathyroid hormone (PTH) in non-ischemic cardiomyopathy (CM) and its underlying mechanism. A total of 30 Sprague-Dawley male rats were randomly divided into a control group (n=6) and an experimental group (n=24). To induce CM in the rats of the experimental group, 2 mg/kg Adriamycin (ADR) was administered intraperitoneally with 5 equal injections every third day followed by 5 weekly injections resulting in a cumulative dose of 20 mg/kg. Following establishment of the model, rats in the experimental group were subdivided into a PTH-untreated CM group that received daily normal saline subcutaneous injections for 7 days and three treated CM groups that received daily subcutaneous injections of 5, 10, or 20 µg/kg of recombinant PTH for 7 days. Rats in the control group accordingly received intraperitoneal and subcutaneous injections of normal saline. Blood sample analysis revealed that B-type natriuretic peptide (BNP), troponin T, C-reactive protein (CRP), creatinine and phosphorus concentrations were increased in the PTH-untreated CM group compared with that in the control group, whereas PTH and calcium concentrations were decreased. Administration of PTH dose-dependently decreased BNP, CRP, creatinine and phosphorus levels, and increased PTH and calcium levels. Notably, there were significant differences in PTH, BNP, troponin T, CRP, creatinine, calcium, and phosphorus levels among the rats in the five groups (P<0.01). Cardiac ultrasonography results indicated that the left ventricular ejection fraction (LVEF) was significantly decreased in rats treated with ADR compared with the rats from the control group (P<0.01). However, the LVEF gradually recovered with elevated PTH treatment doses. The overall differences of LVEF and left ventricular end-systolic volume in the five experimental groups were statistically significant (P<0.01). Furthermore, there were dose-dependent increases in LV mass and left ventricular end-diastolic volume in PTH-treated rats; however, the differences between any two groups did not reach statistical significance (P>0.05). Immunohistochemical staining and western blot analysis using an anti-PTH polyclonal antibody was performed to evaluate the protein expression levels of PTH in myocardial tissues. The mRNA expression levels of PTH and BNP were measured using reverse transcription-quantitative polymerase chain reaction. The results demonstrated that the mRNA and protein expression levels of PTH in myocardial tissues were significantly decreased in ADR-treated rats compared with the levels in the control group rats. Injection of recombinant PTH significantly increased PTH expression and reduced BNP expression in dose-dependent manners (P<0.05). These findings demonstrated that PTH can improve cardiac function in rats with ADR-induced CM, suggesting a potential therapeutic application for PTH in non-ischemic CM.

9.
Cardiovasc Pathol ; 24(6): 375-81, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26164195

RESUMEN

INTRODUCTION: Hyperglycemia-induced reactive oxygen species (ROS) generation contributes to the development of diabetic cardiomyopathy. However, little is known about the role of microRNAs in the regulation of ROS formation and myocardial apoptosis in streptozotocin (STZ)-induced diabetic mice. METHODS AND RESULTS: It was observed that microRNA-144 (miR-144) level was lower in heart tissues of STZ-induced diabetic mice. High glucose exposure also reduced miR-144 levels in cultured cardiomyocytes. Moreover, miR-144 modulated high glucose-induced oxidative stress in cultured cardiomyocytes by directly targeting nuclear factor-erythroid 2-related factor 2 (Nrf2), which was a central regulator of cellular response to oxidative stress. The miR-144 mimics aggravated high glucose-induced ROS formation and apoptosis in cardiomyocytes, which could be attenuated by treatment with Dh404, an activator of Nrf2. Meanwhile, inhibition of miR-144 suppressed ROS formation and apoptosis induced by high glucose in cultured cardiomyocytes. What was more important is that reduced myocardial oxidative stress and apoptosis and improved cardiac function were identified in STZ-induced diabetic mice when treated with miR-144 antagomir. CONCLUSION: Although miR-144 cannot explain the increased oxidative stress in STZ, therapeutic interventions directed at decreasing miR-144 may help to decrease oxidative stress in these hearts. Inhibition of miR-144 might have clinical potential to abate oxidative stress as well as to reduce cardiomyocyte apoptosis and improve cardiac function in diabetic cardiomyopathy.


Asunto(s)
Apoptosis , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/terapia , Cardiomiopatías Diabéticas/prevención & control , MicroARNs/metabolismo , Miocitos Cardíacos/metabolismo , Oligonucleótidos/administración & dosificación , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Estreptozocina , Regiones no Traducidas 3' , Animales , Células Cultivadas , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patología , Cardiomiopatías Diabéticas/inducido químicamente , Cardiomiopatías Diabéticas/genética , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/patología , Glucosa/metabolismo , Masculino , Ratones Endogámicos C57BL , MicroARNs/genética , Miocitos Cardíacos/patología , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Transducción de Señal , Transfección , Función Ventricular Izquierda
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