RESUMO
As an animal's surface area expands during development, skin cell populations must quickly respond to maintain sufficient epithelial coverage. Despite much progress in understanding of skin cell behaviours in vivo1,2, it remains unclear how cells collectively act to satisfy coverage demands at an organismic level. Here we created a multicolour cell membrane tagging system, palmskin, to monitor the entire population of superficial epithelial cells (SECs) in developing zebrafish larvae. Using time-lapse imaging, we found that many SECs readily divide on the animal body surface; during a specific developmental window, a single SEC can produce a maximum of four progeny cells over its lifetime on the surface of the animal. Remarkably, EdU assays, DNA staining and hydroxyurea treatment showed that these terminally differentiated skin cells continue splitting despite an absence of DNA replication, causing up to 50% of SECs to exhibit reduced genome size. On the basis of a simple mathematical model and quantitative analyses of cell volumes and apical surface areas, we propose that 'asynthetic fission' is used as an efficient mechanism for expanding epithelial coverage during rapid growth. Furthermore, global or local manipulation of body surface growth affects the extent and mode of SEC division, presumably through tension-mediated activation of stretch-activated ion channels. We speculate that this frugal yet flexible mode of cell proliferation might also occur in contexts other than zebrafish skin expansion.
Assuntos
Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Células Epiteliais/metabolismo , Larva/metabolismo , Pele/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
This study investigates the potential utility of IKZF1 deletion as an additional high-risk marker for paediatric acute lymphoblastic leukaemia (ALL). The prognostic impact of IKZF1 status, in conjunction with minimal/measurable residual disease (MRD), was evaluated within the MRD-guided TPOG-ALL-2013 protocol using 412 newly diagnosed B-ALL patients aged 1-18. IKZF1 status was determined using multiplex ligation-dependent probe amplification. IKZF1 deletions, when co-occurring with CDKN2A, CDKN2B, PAX5 or PAR1 region deletions in the absence of ERG deletions, were termed IKZF1plus. Both IKZF1 deletion (14.6%) and IKZF1plus (7.8%) independently predicted poorer outcomes in B-ALL. IKZF1plus was observed in 4.1% of Philadelphia-negative ALL, with a significantly lower 5-year event-free survival (53.9%) compared to IKZF1 deletion alone (83.8%) and wild-type IKZF1 (91.3%) (p < 0.0001). Among patients with Day 15 MRD ≥0.01%, provisional high-risk patients with IKZF1plus exhibited the worst outcomes in event-free survival (42.0%), relapse-free survival (48.0%) and overall survival (72.7%) compared to other groups (p < 0.0001). Integration of IKZF1plus and positive Day 15 MRD identified a subgroup of Philadelphia-negative B-ALL with a 50% risk of relapse. This study highlights the importance of assessing IKZF1plus alongside Day 15 MRD positivity to identify patients at increased risk of adverse outcomes, potentially minimizing overtreatment.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Deleção de Genes , Fator de Transcrição Ikaros/genética , Recidiva Local de Neoplasia , Neoplasia Residual/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prognóstico , Medição de Risco , Fatores de Transcrição , Lactente , Pré-Escolar , AdolescenteRESUMO
Reactions on post-transition-state bifurcation (PTSB) energy surfaces are an important class of reaction in which classical rate theories, such as the transition state theory, fail to account for the selectivity. Quasiclassical trajectory molecular dynamic (QCT-MD) simulation is an important computational approach to understanding reactions mechanisms, especially for reactions that cannot be predicted from conventional rate theories. However, the applicability of direct dynamic simulations is hampered by huge computational costs for collecting a statistically meaningful set of trajectories, making it difficult to compare simulation results with theoretical or physical insights-based predictions (non-MD predictions). In this work, we examine the PTSB of Schmidt-Aubé reactions studied by Tantillo and co-workers. With machine-learning using kernel-ridge regression (KRR) to predict atomic forces, statistical reliability was enhanced by significantly increasing the number of trajectories. With KRR, the bottleneck of simulating dynamics (atomic forces in QCT-MD with density functional theory) was accelerated more than 100-fold. We found that this KRR-aided QCT-MD approach is successful in predicting branching ratios with a much larger number of trajectories. With our approach, statistical errors are greatly reduced, and hypothetical non-MD models for predicting selectivity are tested with much higher confidence. By comparison with non-MD models, dynamical properties that affect branching ratios become more clearly described.
RESUMO
Electronic coupling is important in determining charge-transfer rates and dynamics. Coupling strength is sensitive to both intermolecular, e.g., orientation or distance, and intramolecular degrees of freedom. Hence, it is challenging to build an accurate machine learning model to predict electronic coupling of molecular pairs, especially for those derived from the amorphous phase, for which intermolecular configurations are much more diverse than those derived from crystals. In this work, we devise a new prediction algorithm that employs two consecutive KRR models. The first model predicts molecular orbitals (MOs) from structural variation for each fragment, and coupling is further predicted by using the overlap integral included in a second model. With our two-step procedure, we achieved mean absolute errors of 0.27 meV for an ethylene dimer and 1.99 meV for a naphthalene pair, much improved accuracy amounting to 14-fold and 3-fold error reductions, respectively. In addition, MOs from the first model can also be the starting point to obtain other quantum chemical properties from atomistic structures. This approach is also compatible with a MO predictor with sufficient accuracy.
RESUMO
Background: Transcription factor 21 (TCF21, epicardin, capsuling, pod-1) is expressed in the epicardium and is involved in the regulation of cell fate and differentiation via epithelial-mesenchymal transformation during development of the heart. In addition, TCF21 can suppress the differentiation of epicardial cells into vascular smooth muscle cells and promote cardiac fibroblast development. This study aimed to explore whether TCF21 gene (12190287G/C) variants affect coronary artery disease risk. Methods: We enrolled 381 patients who had stable angina, 138 with ST elevation myocardial infarction (STEMI), and 276 healthy subjects. Genotyping of rs12190287 of the TCF21 gene was performed. Results: Higher frequencies of the CC genotype were found in the patients with stable angina/STEMI than in the healthy controls. After adjusting for diabetes mellitus, hypertension, age, sex, smoking, body mass index and hyperlipidemia, the patients with the CC genotype of the TCF21 gene were associated with 2.49- and 9.19-fold increased risks of stable angina and STEMI, respectively, compared to the patients with the GG genotype. Furthermore, TCF21 CC genotypes showed positive correlations with both stable angina and STEMI, whereas TCF21 GG genotypes exhibited a negative correlation with STEMI. Moreover, the stable angina and STEMI patients with the CC genotype had significantly elevated high-sensitivity C-reactive protein levels than those with the GG genotype. In addition, significant associations were found between type 2 diabetes mellitus, hypertension, and hyperlipidemia with TCF21 gene polymorphisms (p for trend < 0.05). Conclusion: TCF21 gene polymorphisms may increase susceptibility to stable angina and STEMI.
Assuntos
Angina Estável , Diabetes Mellitus Tipo 2 , Hiperlipidemias , Hipertensão , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Angina Estável/genética , Infarto do Miocárdio com Supradesnível do Segmento ST/genética , China , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genéticaRESUMO
PURPOSE: To evaluate the effectiveness of marrow stimulation (MS) versus biphasic scaffold loaded with autologous cartilage (scaffold) in treating focal osteochondral lesions of the knee. METHODS: In total, 54 patients with symptomatic focal chondral or osteochondral lesion in the knee were randomized to either the scaffold group or the MS group. International Knee Documentation Committee subjective score, the Knee Injury Osteoarthritis Outcome Score, and magnetic resonance imaging (MRI) were assessed preoperatively and at 1 and 2 years after operation to compare treatment outcomes. Biopsy and second-look arthroscopy were performed at 1 year postoperatively for consenting patients. RESULTS: There were 27 patients (mean age 31.33 ± 10.95 years) in the scaffold group, and 27 patients (31.74 ± 11.44) in the MS group. The scaffold group and the MS group both included 23 patients with lesions ≤12.5 × 12.5 mm2 mm in size. In addition, each group had 4 patients with lesions between than 12.5 × 12.5 mm2 and ≤12.5 × 25 mm2. Both interventions achieved significant improvement in clinical outcome scores at 2 years. The scaffold group had greater International Knee Documentation Committee score than the MS group at 2 years (93.85 ± 9.55 vs 92.11 ± 9.84) and in the Symptoms/Stiffness and Sport/Recreation subscales of Knee Injury Osteoarthritis Outcome Score at 2 years (96.57 ± 5.97 vs 93.57 ± 6.52, P < .05) and (90.2 ± 17.76 vs 82.8 ± 16.08, P < .05). CONCLUSIONS: The use of biphasic scaffold loaded with autologous cartilage in treating focal osteochondral lesions demonstrates superior clinical outcomes and better cartilage refill on magnetic resonance imaging at the 2-year follow-up compared to marrow stimulation. LEVEL OF EVIDENCE: Level I, Randomized controlled trial.
RESUMO
We proposed a single-layer color echelle grating combined optical waveguide structure for an augmented-reality display. In this structure, we used echelle gratings with super-wavelength periodic scale as in-coupling, relay, and out-coupling elements. The combined propagation of three light beams in the waveguide was realized by overlapping different high diffraction orders of the RGB three primary colors, and deflection of the beam direction between gratings was achieved by conical diffraction generated by the inclined grating. Using the vector diffraction theory, the structural parameters and tolerance ranges of the three types of gratings were optimized, rendering average diffraction efficiencies of the three primary colors of the in-coupling, relay, and out-coupling gratings greater than 74%, 21%, and 35%, respectively. As a result, we obtained dual-channel one-dimensional pupil dilation of the original image and a field-of-view angle of h18.9° × v36.87°.
RESUMO
We present an implantable metaverse featuring retinal prostheses in association with bionic vision processing. Unlike conventional retinal prostheses, whose electrodes are spaced equidistantly, our solution is to rearrange the electrodes to match the distribution of ganglion cells. To naturally imitate the human vision, a scheme of bionic vision processing is developed. On top of a three-dimensional eye model, our bionic vision processing is able to visualize the monocular image, binocular image fusion, and parallax-induced depth map.
Assuntos
Próteses Visuais , Humanos , Biônica , Percepção Visual , Visão Ocular , EletrodosRESUMO
In recent years, augmented/virtual reality (AR/VR) has been attracting attention and investment in both the tech and academic communities, kickstarting a new wave of innovations. In the wake of this momentum, this feature issue was launched to cover the latest advances in this burgeoning field that pertains to optics and photonics. Alongside the 31 research articles being published, this introduction is appended to share with readers the behind-the-issue stories, submission statistics, reading guides, author biographies, and editors' perspectives.
RESUMO
Electron transfer (ET) is a fundamental process in chemistry and biochemistry, and electronic coupling is an important determinant of the rate of ET. However, the electronic coupling is sensitive to many nuclear degrees of freedom, particularly those involved in intermolecular movements, making its characterization challenging. As a result, dynamic disorder in electron transfer coupling has rarely been investigated, hindering our understanding of charge transport dynamics in complex chemical and biological systems. In this work, we employed molecular dynamic simulations and machine-learning models to study dynamic disorder in the coupling of hole transfer between neighboring ethylene and naphthalene dimer. Our results reveal that low-frequency modes dominate these dynamics, resulting primarily from intermolecular movements such as rotation and translation. Interestingly, we observed an increasing contribution of translational motion as temperature increased. Moreover, we found that coupling is sub-Ohmic in its spectral density character, with cut-off frequencies in the range of 102 cm-1. Machine-learning models allow direct study of dynamics of electronic coupling in charge transport with sufficient ensemble trajectories, providing further new insights into charge transporting dynamics.
RESUMO
BACKGROUND: Primary malignant mediastinal germ cell tumors (GCTs) are rare pediatric tumors that have a poorer prognosis compared to GCTs occurring elsewhere in the body. The current study aimed to assess the prognostic factors and treatment outcomes of children with primary malignant mediastinal GCT in Taiwan. METHODS: The authors retrospectively reviewed children 0-18 years old who were newly diagnosed with primary malignant mediastinal GCT between January 1, 2005 and December 31, 2019 and were registered in the Taiwan Pediatric Oncology Group patient registry. The impact of presenting characteristics, including sex, age, tumor stage, histology subtype, surgical treatment, and chemotherapy regimens of the patients were analyzed. RESULTS: This study enrolled 52 children with malignant mediastinal GCT who had a median age of 16.0 (range, 6.0-17.9) years at diagnosis. The most common histological subtypes were mixed GCTs (n = 20) and yolk sac tumors (n = 15). Advanced disease stage and choriocarcinoma histology subtype were associated inferior outcomes. Children who received surgical treatment exhibited better outcomes compared to those who did not (5-year overall survival, 78% vs. 7%, p < .001). After comparing patients who received first-line cisplatin- and carboplatin-based chemotherapy, no difference in treatment outcomes was observed. Multivariate analysis showed that surgical management was the only independent predictor for superior OS. CONCLUSIONS: Surgical treatment is recommended for mediastinal GCT. Cisplatin-based chemotherapy was not superior to carboplatin-based chemotherapy as first-line treatment and may be avoided due to toxicity concerns.
Assuntos
Neoplasias do Mediastino , Neoplasias Embrionárias de Células Germinativas , Criança , Humanos , Adolescente , Recém-Nascido , Lactente , Pré-Escolar , Prognóstico , Cisplatino , Carboplatina/uso terapêutico , Estudos Retrospectivos , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Embrionárias de Células Germinativas/cirurgia , Neoplasias do Mediastino/terapiaRESUMO
We establish an approach to measure the nonclassicality of a two-mode quantum state by extending the method of quantifying nonclassicality for a single-mode quantum state. We then discuss the nonclassicality and entanglement properties of several different quantum states, and determine the optimal phase estimation for entangled coherent states (ecs) in the form of nonclassicality and concurrence. Accordingly, a new interferometer (linear and nonlinear) scheme is proposed by modifying a traditional interferometer. Specially, we specify a new normal ordering form of the evolution operator of nonlinear interferometer (NI) using the techniques of integration within an ordered product of operators (IWOP), and obtain the parity signal based on representation of the coherent state. By inputting several common quantum states, we further study the phase sensitivity of the linear interferometer (LI) and NI with parity detection, and perform a detailed comparison among the different input states schemes. Furthermore, we quantitatively investigated the effect of nonclassicality and entanglement on the phase sensitivity of two interferometers. These results show that nonclassicality or entanglement is very crucial but not a necessary condition for improving the phase sensitivity of interferometers.
RESUMO
We present a near-eye display featuring a triple-channel waveguide with chiral liquid crystal gratings. Our triple-channel waveguide is capable of dividing one field of view into three through both the polarization orthogonality and angular separation. To illustrate its principle, a k-space diagram, which takes into account the aspect ratio of field of view, is depicted. Our results demonstrate that its diagonal field of view reaches 90°, eye relief is 10 mm, exit pupil is 4.9 × 4.9 mm2, transmittance is 4.9%, and uniformity is 89%.
Assuntos
Cristais Líquidos , Pupila , Desenho de EquipamentoRESUMO
Since the water oxidation half-reaction requires the transfer of multi-electrons and the formation of O-O bond, it's crucial to investigate the catalytic behaviours of semiconductor photoanodes. In this work, a bio-inspired copper-bipyridine catalyst of Cu(dcbpy) is decorated on the nanoporous Si photoanode (black Si, b-Si). Under AM1.5G illumination, the b-Si/Cu(dcbpy) photoanode exhibits a high photocurrent density of 6.31â mA cm-2 at 1.5 VRHE at pHâ 11.0, which is dramatically improved from the b-Si photoanode (1.03â mA cm-2 ) and f-Si photoanode (0.0087â mA cm-2 ). Mechanism studies demonstrate that b-Si/Cu(dcbpy) has improved light-harvesting, interfacial charge-transfer, and surface area for water splitting. More interestingly, b-Si/Cu(dcbpy) exhibits a pH-dependent water oxidation behaviour with a minimum Tafel slope of 241â mV/dec and the lowest overpotential of 0.19â V at pHâ 11.0, which is due to the monomer/dimer equilibrium of copper catalyst. At pH â¼11, the formation of dimeric hydroxyl-complex could form O-O bond through a redox isomerization (RI) mechanism, which decreases the required potential for water oxidation. This in-depth understanding of pH-dependent water oxidation catalyst brings insights into the design of dimer water oxidation catalysts and efficient photoanodes for solar energy conversion.
RESUMO
BACKGROUND: Fibroblast growth factor 21 (FGF21) is produced by cardiac cells, may acts in an autocrine manner, and was suggested to has a cardioprotective role in atherosclerosis. Wide QRS complex and heart rate-corrected QT interval (QTc interval) prolongation are associated to dangerous ventricular arrhythmias and cardiovascular disease mortality. Yet, the role of FGF21 in cardiac arrhythmia has never been studied. The aim of the study was to investigate the relationship between plasma FGF21 and the QRS duration and QTc interval in patients with stable angina. METHODS: Three hundred twenty-one consecutive stable angina patients were investigated. Plasma FGF21 was measured through ELISA, and each subject underwent 12-lead electrocardiography. RESULTS: FGF21 plasma levels were positively associated with the QRS duration (ß = 0.190, P = 0.001) and QTc interval (ß = 0.277, P < 0.0001). With increasing FGF21 tertiles, the patients had higher frequencies of wide QRS complex and prolonged QTc interval. After adjusting for patients' anthropometric parameters, the corresponding odd ratios (ORs) for wide QRS complex of the medium and high of FGF21 versus the low of FGF21 were 1.39 (95% CI 0.51-3.90) and 4.41 (95% CI 1.84-11.59), respectively, and p for trend was 0.001. Furthermore, multiple logistic regression analysis also showed the corresponding odd ratios (ORs) for prolonged QTc interval of the medium and high of FGF21 versus the low of FGF21 were 1.02 (95% CI 0.53-1.78) and 1.93 (95% CI 1.04-3.60) respectively with the p for trend of 0.037. In addition, age- and sex-adjusted FGF21 levels were positively associated with fasting glucose, HbA1c, creatinine, and adiponectin, but negatively associated with albumin, and the estimated glomerular filtration rate. CONCLUSIONS: This study indicates that plasma FGF21 is associated with wide QRS complex and prolonged corrected QT interval in stable angina patients, further study is required to investigate the role of plasma FGF21 for the underlying pathogenesis.
Assuntos
Angina Estável , Fatores de Crescimento de Fibroblastos , Síndrome do QT Longo , Humanos , Adiponectina , Albuminas , Arritmias Cardíacas , Creatinina , Eletrocardiografia , Eletrólitos , Fatores de Crescimento de Fibroblastos/metabolismo , Glucose , Hemoglobinas GlicadasRESUMO
Background: Obesity and cognitive function decline are independent risk factors for chronic kidney disease (CKD). However, few studies have examined the combined effects of obesity status and cognitive function on change in CKD risk. We aimed to evaluate the association between obesity status, cognitive function and CKD risk change in patients with type 2 diabetes mellitus (T2DM). Methods: Data on 3399 T2DM patients were extracted from a diabetes disease management program between 2006 and 2018. Univariate and multivariate analyses were used to assess the association between obesity, cognitive decline, and CKD risk change. Three indexes, including the relative excess risk of interaction (RERI), attributable proportion of interaction (API), and synergy index (SI), were used to analyze interactions. CKD risk was classified according to the KDIGO 2012 CKD definition. Results: In multivariate analysis, the hazard ratio (HR, 95%Cis) for CKD risk progression was 1.34 (1.12-1.61) times higher in the moderate and severely obese patients compared with the normal weight patients, and 1.34 (1.06-1.67) times higher in the patients with a Mini-Mental State Examination (MMSE) score ≤18 compared to those with an MMSE score ≥24. There was a synergistic interaction between moderate and severe obesity and MMSE score ≤18 on CKD risk progression (SI=4.461; 95% CI: 1.998-9.962), and the proportion of CKD risk progression caused by this interaction was 52.7% (API=0.527; 95% CI: 0.295-0.759). However, normal weight and MMSE score ≥24 were not beneficial on CKD risk improvement in the patients with a moderate risk and very high-risk stage of CKD. Conclusion: There may be a synergistic interaction between obesity and cognitive function decline, and the synergistic interaction may increase the risk of CKD progression.
Assuntos
Disfunção Cognitiva , Diabetes Mellitus Tipo 2 , Insuficiência Renal Crônica , Cognição , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Progressão da Doença , Taxa de Filtração Glomerular , Humanos , Obesidade/complicações , Obesidade/epidemiologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Fatores de RiscoRESUMO
We reformulate the thermally assisted-occupation density functional theory (TAO-DFT) into the Kohn-Sham single-determinant framework and construct two new post-self-consistent field (post-SCF) static correlation correction schemes, named rTAO and rTAO-1. In contrast to the original TAO-DFT with the density in an ensemble form, in which each orbital density is weighted with a fractional occupation number, the ground-state density is given by a single-determinant wavefunction, a regular Kohn-Sham (KS) density, and total ground state energy is expressed in the normal KS form with a static correlation energy formulated in terms of the KS orbitals. In post-SCF calculations with rTAO functionals, an efficient energy scanning to quantitatively determine θ is also proposed. The rTAOs provide a promising method to simulate systems with strong static correlation as original TAO, but simpler and more efficient. We show that both rTAO and rTAO-1 is capable of reproducing most results from TAO-DFT without the additional functional Eθ used in TAO-DFT. Furthermore, our numerical results support that, without the functional Eθ, both rTAO and rTAO-1 can capture correct static correlation profiles in various systems.
RESUMO
BACKGROUND & AIMS: Aging is a pathophysiological process driven by a diverse set of complex biological processes, and environmental pollution plays an important role in this process. This study aimed to explore the association between serum α-Klotho levels and urinary perchlorate, nitrate, and thiocyanate levels. METHODS: This secondary dataset analysis included 4875 participants (mean age, 57.69 year; male, 49.58%; non-Hispanic White, 47.67%) from the US National Health and Nutrition Examination Survey (2007-2014). Enzyme-linked immunosorbent assay was used to quantify α-Klotho levels, and ion chromatography coupled with electrospray tandem mass spectrometry was used to quantify thiocyanate, nitrate, and perchlorate levels. Multivariate linear regression models were applied to estimate the association between perchlorate, nitrate, and thiocyanate levels and serum α-Klotho levels. RESULTS: Urinary thiocyanate levels were negatively associated with α-Klotho levels (ß = - 0.006; 95% confidence interval, - 0.010 to - 0.003; P = 0.0004) after adjusting for age, sex, body mass index, race, alcohol consumption, estimated glomerular filtration rate, underlying disease, physical activity, smoking status, usual energy intake, and urinary creatinine and serum cotinine levels and mutual adjustment of urinary perchlorate, urinary nitrate, and urinary thiocyanate levels. The α-Klotho level in participants in the highest quartile was higher by 50.567 ng/mL (ß = 50.567; 95% confidence interval, 14.407 to 86.726; P = 0.009) than that in participants in the lowest quartile of urinary perchlorate. A linear relationship was observed between urinary thiocyanate and α-Klotho levels. CONCLUSIONS: Urinary thiocyanate levels were negatively associated with serum α-Klotho levels. Urinary thiocyanate should be further investigated as a potential mediator of aging and age-related diseases.
Assuntos
Percloratos , Tiocianatos , Exposição Ambiental/efeitos adversos , Humanos , Masculino , Nitratos/urina , Inquéritos Nutricionais , Percloratos/urina , Tiocianatos/urinaRESUMO
BACKGROUND: Growth differentiation factor 1 (GDF1) is a member of the transforming growth factor-ß (TGF-ß) superfamily and a protective mediator against the development of post-infarction cardiac remodeling by negatively regulating MEK-ERK1/2 and Smad signaling pathways in the heart. The TGF-ß/SMAD pathway has been shown to play a key role in the development of hepatic fibrosis. In addition, fatty liver disease has been associated with reduced MEK/ERK1/2 signaling. However, no previous study has investigated the association between GDF1 and liver fibrosis. Therefore, the aim of this study was to investigate the association between plasma GDF1 and liver fibrosis in patients with stable angina. METHODS: We included 327 consecutive patients with stable angina. ELISA was used to measure circulating levels of GDF1, and the fibrosis-4 index was used to assess liver fibrosis. RESULTS: The advanced liver fibrosis group had lower median plasma GDF1 levels than those with minimal liver fibrosis. There was a significant negative association between GDF1 plasma level and fibrosis-4 index (r = -0.135, p = 0.019). A lower concentration of GDF1 was significantly and independently associated with an increased risk of liver fibrosis when concentration was analyzed as a continuous variable and by tertile. In addition, fibrosis-4 index, aspartate aminotransferase (AST)-to-platelet ratio index, and AST/alanine aminotransferase ratio were significantly associated with GDF1 concentration. CONCLUSIONS: Our results indicated an association between low plasma GDF1 and liver fibrosis in the enrolled patients. Further investigations into the role of plasma GDF1 in the pathogenesis of liver fibrosis are warranted.
Assuntos
Angina Estável , Fator 1 de Diferenciação de Crescimento , Cirrose Hepática , Humanos , Fator 1 de Diferenciação de Crescimento/sangue , Fígado/metabolismo , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
In this paper, we consider the problem of bearing ambiguity in the direction of arrival (DOA) estimation due to spatial aliasing when the minimum wavelength of the processing broadband signal is less than the element spacing of a uniform linear array (ULA). First, an extended frequency-difference (FD) method is presented. Unlike the existing FD methods, the extended FD signal is constructed by conjugate multiplying a diagonal matrix consisting of steering vectors at high frequency and pre-processing direction with the array sampled signal matrix at low frequency. Then, this paper establishes a decision criterion for distinguishing the aliasing component that varies linearly with frequency in the extended FD space. Finally, an unambiguous broadband DOA estimation method is achieved by suppressing spatial aliasing in the extended FD space. The simulation results show the effectiveness of the proposed method in low signal-to-noise ratio, low signal-to-interference ratio, and multi-interference conditions. The unambiguous processing ability of the proposed method is further verified in the South China Sea using ship signals in the frequency band of 200 to 700 Hz and a 10-element ULA with a 6.25 m spacing deployed on the seabed.