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1.
J Environ Manage ; 352: 120055, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38184868

RESUMO

The kinetics knowledge of lignocellulosic biomass decomposition is essential to develop efficient thermochemical conversion technology. However, the simplification of reaction mechanisms in existing oxidative pyrolysis studies largely compromises the application of kinetic models. To explore more exact kinetic parameters and reaction mechanism of lignocellulosic biomass oxidative pyrolysis, an updated oxidative pyrolysis kinetic model (seven-step reaction combined kinetics model) coupled with an optimization algorithm is proposed. Based on a series of thermogravimetric experiments in an air atmosphere, the extra oxidative pyrolysis kinetic parameters are obtained by the Shuffled Complex Evolution method. The proposed kinetic model is validated based on the degradation process of each component (hemicellulose, cellulose, and lignin). Furthermore, the obtained kinetic parameters are applied to predict the oxidative pyrolysis behavior, and the predicted mass loss rate is in good agreement with the experimental data. Eventually, according to the key combined kinetics parameters, it is found that the oxidative pyrolysis mechanisms of hemicellulose, cellulose, and lignin correspond to the power law, nucleation & growth, and chemical reaction order, respectively, while the combustion of char corresponds to the reaction order mechanism.


Assuntos
Lignina , Pirólise , Lignina/química , Biomassa , Termogravimetria , Celulose/química , Cinética , Estresse Oxidativo
2.
J Environ Manage ; 367: 121933, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39083936

RESUMO

Hydrological models are vital tools in environmental management. Weaknesses in model robustness for hydrological parameters transfer uncertainties to the model outputs. For streamflow, the optimized parameters are the primary source of uncertainty. A reliable calibration approach that reduces prediction uncertainty in model simulations is crucial for enhancing model robustness and reliability. The optimization of parameter ranges is a key aspect of parameter calibration, yet there is a lack of literature addressing the optimization of parameter ranges in hydrological models. In this paper, we introduce a parameter calibration strategy that applies a clustering technique, specifically the Self-Organizing Map (SM), to intelligently navigate the parameter space during the calibration of the Soil and Water Assessment Tool (SWAT) model for monthly streamflow simulation in the Baishan Basin, Jilin Province, China. We selected the representative algorithm, the Sequential Uncertainty Fitting version 2 (SUFI-2), from the commonly used SWAT Calibration and Uncertainty Programs for comparison. We developed three schemes: SUFI-2, SUFI-2-Narrowing Down (SUFI-2-ND), and SM. Multiple diagnostic error metrics were used to compare simulation accuracy and prediction uncertainty. Among all schemes, SM outperformed the others in describing watershed streamflow, particularly excelling in the simulation of spring snowmelt runoff (baseflow period). Additionally, the prediction uncertainty was effectively controlled, demonstrating the SM's adaptability and reliability in the interval optimization process. This provides managers with more credible prediction results, highlighting its potential as a valuable calibration tool in hydrological modeling.


Assuntos
Hidrologia , Calibragem , Modelos Teóricos , Algoritmos , Incerteza , China , Solo
3.
J Mol Cell Cardiol ; 151: 31-43, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32971071

RESUMO

Pathological cardiac hypertrophy is a crucial cause of cardiac morbidity and mortality worldwide. However, the molecular mechanisms of this disease remain incompletely understood. As a member of E3 ubiquitin ligases, F-box/WD repeat-containing protein 5 (FBXW5) has been implicated in various pathophysiological processes. However, the role of FBXW5 in pathological cardiac hypertrophy remains largely unknown. In this study, decreased expression of FBXW5 was observed in both neonatal rat cardiomyocytes and mouse hearts with hypertrophic remodeling. Gain- and loss-of-function experiments were performed to study the potential function of FBXW5 in pathological cardiac hypertrophy. The in vitro results showed that FBXW5 had a protective effect against cardiac hypertrophy induced by phenylephrine (PE). FBXW5 knockout mice and mice with AAV9-mediated FBXW5 overexpression were generated. Consistent with the in vitro results, FBXW5 deficiency aggravated cardiac hypertrophy induced by pressure overload. FBXW5 overexpression protected mice from hypertrophic stimuli. Remarkably, FBXW5 ameliorated pathological cardiac hypertrophy by directly interacting with the protein transforming growth factor-beta-activated kinase 1 (TAK1) and blocking the mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, inhibition of TAK1 prevented the effects of FBXW5 on agonist- or pressure overload-induced cardiac hypertrophy. These findings imply that FBXW5 is an essential negative regulator and may be a potential therapeutic target for pathological cardiac hypertrophy.


Assuntos
Cardiomegalia/metabolismo , Cardiomegalia/patologia , Proteínas F-Box/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases , Animais , Animais Recém-Nascidos , Dependovirus/metabolismo , Regulação para Baixo , Fibrose , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos Knockout , Poliubiquitina/metabolismo , Ligação Proteica , Ratos , Ubiquitinação , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Am J Transplant ; 21(6): 2067-2078, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33210808

RESUMO

Complement is known to play a role in ischemia and reperfusion injury (IRI). A general paradigm is that complement is activated by self-reactive natural IgM antibodies (nAbs), after they engage postischemic neoepitopes. However, a role for nAbs in lung transplantation (LTx) has not been explored. Using mouse models of LTx, we investigated the role of two postischemic neoepitopes, modified annexin IV (B4) and a subset of phospholipids (C2), in LTx. Antibody deficient Rag1-/- recipient mice were protected from LTx IRI. Reconstitution with either B4 or C2nAb restored IRI, with C2 significantly more effective than B4 nAb. Based on these information, we developed/characterized a novel complement inhibitor composed of single-chain antibody (scFv) derived from the C2 nAb linked to Crry (C2scFv-Crry), a murine inhibitor of C3 activation. Using an allogeneic LTx, in which recipients contain a full nAb repertoire, C2scFv-Crry targeted to the LTx, inhibited IRI, and delayed acute rejection. Finally, we demonstrate the expression of the C2 neoepitope in human donor lungs, highlighting the translational potential of this approach.


Assuntos
Lesão Pulmonar , Transplante de Pulmão , Traumatismo por Reperfusão , Transplantes , Animais , Inativadores do Complemento , Humanos , Imunoglobulina M , Transplante de Pulmão/efeitos adversos , Camundongos , Traumatismo por Reperfusão/prevenção & controle
5.
Radiology ; 300(2): 470-478, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34060938

RESUMO

Background Endoscopic retrograde cholangiopancreatography (ERCP) is recommended by major guidelines for the removal of common bile duct (CBD) stones but is technically challenging in patients with low cardiopulmonary reserve and anatomic abnormalities of the upper gastrointestinal (GI) tract. Purpose To compare percutaneous transhepatic papillary balloon dilation (PTPBD) with ERCP for CBD stone removal. Materials and Methods Participants with one to three CBD stones (largest stone ≤30 mm) and without intrahepatic bile duct or gallbladder stones were eligible for this prospective cohort study. PTPBD was recommended in participants with low cardiopulmonary reserve or definitive anatomic abnormalities of the upper GI tract. Otherwise, both procedures were offered without preference. Follow-up, including abdominal CT, was conducted at 1-week and 1-, 3- and 6-month follow-up, and every 6 months thereafter. US and MR cholangiopancreatography were conducted if recurrence could not be confirmed with CT. Technical success rate was the primary outcome. Results A total of 531 participants were analyzed: there were 360 undergoing PTPBD (median age, 76 years; interquartile range [IQR], 64-82 years; 163 men) and 171 undergoing ERCP (median age, 66 years; IQR, 57-74 years; 94 men). The technical success rate was 99% (355 of 360) in the PTPBD group and 98% (167 of 171) in the ERCP group (relative risk, 1.02; P = .12). The incidence of overall complications was 4% (13 of 360) for PTPBD and 8% (13 of 171) for ERCP (relative risk, 0.27; 95% CI: 0.12, 0.61; P < .001). The PTPBD group showed a longer fluoroscopy time and a higher radiation exposure, with adjusted differences of 28.7 minutes (95% CI: 22.2, 35.2) and 384.3 mGy (95% CI: 296.5, 472), respectively. A propensity score-matching analysis (n = 123 per group) indicated that PTPBD had a slightly higher technical success rate and significantly fewer complications. Conclusion When compared with endoscopic retrograde cholangiopancreatography, percutaneous transhepatic papillary balloon dilation has a similar technical success rate and fewer perioperative complications but a higher radiation exposure. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by van Sonnenberg and Mueller in this issue.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Dilatação/métodos , Cálculos Biliares/cirurgia , Idoso , Idoso de 80 Anos ou mais , Feminino , Cálculos Biliares/diagnóstico por imagem , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos
6.
Energy (Oxf) ; 2032020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34433998

RESUMO

A series of experiments have been conducted to study the flame behavior of ethanol pool fires in a closed chamber. The effect of internal pressure and the size of the pool burner is considered. Tests include pressure conditions ranging from 50 kPa to 350 kPa and 5 circular pool burners with different diameters (2 cm, 4 cm, 6 cm, 8 cm, and 10 cm). Measurements such as gas temperature, internal pressure, oxygen concentration, and video record for all tests are obtained. Steady-state burning period is identified to facilitate a quantitative analysis of flame behavior. Image processing is carried out to obtain time average appearance of pool fires. The concept of oscillation intensity is introduced. Oscillation behaviors of pool fires in a closed system as a function of internal pressure and pan diameter are correlated with oscillation intensity. Four flame structures are observed: laminar, tip flicking, sinuous meandering, and turbulent flame. Relationships between oscillation intensity to flame structure and Grashof number to flame structure are established. Effect of internal pressure and gravitational force to oscillation frequency is also accessed. Simple theoretical model is developed. An empirical expression using the relationship of Strouhal number and Grashof number is established. Two distinct behaviors on oscillation frequency as a function of pressure are observed. Results obtained from this work will facilitate the understanding of oscillation behavior of ethanol pool fires in different sizes with various internal pressure conditions in a closed chamber.

7.
Am J Respir Cell Mol Biol ; 60(6): 678-686, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30571141

RESUMO

Chronic obstructive pulmonary disease-associated chronic inflammation has been shown to lead to an autoimmune phenotype characterized in part by the presence of lung autoreactive antibodies. We hypothesized that ischemia-reperfusion injury (IRI) liberates epitopes that would facilitate preexisting autoantibody binding, thereby exacerbating lung injury after transplant. We induced emphysema in C57BL/6 mice through 6 months of cigarette smoke (CS) exposure. Mice with CS exposure had significantly elevated serum autoantibodies compared with non-smoke-exposed age-matched (NS) mice. To determine the impact of a full preexisting autoantibody repertoire on IRI, we transplanted BALB/c donor lungs into NS or CS recipients and analyzed grafts 48 hours after transplant. CS recipients had significantly increased lung injury and immune cell infiltration after transplant. Immunofluorescence staining revealed increased IgM, IgG, and C3d deposition in CS recipients. To exclude confounding alloreactivity and confirm the role of preexisting autoantibodies in IRI, syngeneic Rag1-/- (recombination-activating protein 1-knockout) transplants were performed in which recipients were reconstituted with pooled serum from CS or NS mice. Serum from CS-exposed mice significantly increased IRI compared with control mice, with trends in antibody and C3d deposition similar to those seen in allografts. These data demonstrate that pretransplant CS exposure is associated with increased IgM/IgG autoantibodies, which, upon transplant, bind to the donor lung, activate complement, and exacerbate post-transplant IRI.


Assuntos
Anticorpos/efeitos adversos , Progressão da Doença , Transplante de Pulmão/efeitos adversos , Enfisema Pulmonar/imunologia , Traumatismo por Reperfusão/etiologia , Animais , Autoanticorpos/sangue , Proteínas do Sistema Complemento/metabolismo , Epitopos/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Enfisema Pulmonar/sangue , Traumatismo por Reperfusão/sangue , Fumar
8.
Small ; 15(50): e1902612, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31595665

RESUMO

Distribution of multimaterials at arbitrary positions with nanoscale resolution and over a large area substrate is essential to future advances in functional graded materials. Such stringent requirements are highly beyond the reach of current techniques, although newly developed 3D printing technologies are addressed. Here, a radial gradient circle array film with the distribution accuracy up to ≈18 nm is fabricated by using microtopographic substrate. A mathematical model is developed to guide the distribution of position, size, shape, and type of materials on an arbitrary section for the given morphology of substrate. The periodic electrical and mechanical properties of the radial gradient circle film are identified, which can be beneficial for further functionalization and applications, such as gradient refractive index lenses, microcoils, and microantennas.

9.
Ann Vasc Surg ; 60: 236-245, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31200041

RESUMO

BACKGROUND: The goal of this study is to evaluate the safety and efficacy of a novel catheter for right radial artery approach cerebral angiography. METHODS: Patients from the Neurology Department of The Second Affiliated Hospital of Guangxi Traditional Chinese Medical University who underwent diagnostic cerebral angiography of either the left vertebral artery dominant type or balanced type were enrolled in this study. RESULTS: A total of 167 patients were treated between February 2016 and December 2017, of whom 44 were excluded based on study exclusion criteria and 123 were enrolled in the present analysis. Bilateral subclavian artery catheterization and bilateral common carotid artery catheterization were conducted successfully in all 123 patients. The success rate of selective catheterization of the left vertebral artery was 87.8% (108/123). The success rate of selective catheterization of the right vertebral artery using the novel catheter was 89.0% (73/82). The average fluoroscopy time was 6.5 ± 3.4 min, the average operation duration was 47 ± 3.7 (range 50-90) min, and the average dosage of contrast agent was 112.3 ± 8.1 mL. One patient exhibited an absence of pulse in the punctual radial artery after the removal of the arterial compression band, but there was no evidence of ischemia of the distal hand. One patient who was undergoing dual anti-platelet drug treatment suffered from bleeding at the puncture point when deflated for 2 hr after operation; this patient was re-pressurized and re-timed. CONCLUSIONS: This novel catheter improved the success rate of selective left vertebral artery catheterization, and allowed for simplification of the relevant surgical steps. The controllability of this novel catheter was satisfactory, and its associated surgical risk was found to be low.


Assuntos
Artéria Carótida Primitiva , Cateterismo Periférico/instrumentação , Angiografia Cerebral/instrumentação , Transtornos Cerebrovasculares/diagnóstico por imagem , Artéria Radial , Artéria Subclávia , Dispositivos de Acesso Vascular , Artéria Vertebral , Idoso , Idoso de 80 Anos ou mais , Artéria Carótida Primitiva/diagnóstico por imagem , Cateterismo Periférico/efeitos adversos , Angiografia Cerebral/efeitos adversos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Artéria Radial/diagnóstico por imagem , Fatores de Risco , Artéria Subclávia/diagnóstico por imagem , Artéria Vertebral/diagnóstico por imagem
10.
Water Sci Technol ; 79(8): 1494-1502, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31169507

RESUMO

Bi2O2CO3 modified graphitic carbon nitride (g-C3N4) nanosheets were prepared by a simple one-pot synthetic strategy. In the presence of ammonium nitrate, different mass ratios of bismuth nitrate/melamine were used to fabricate these catalysts, which were characterized by X-ray diffraction (XRD), N2-physisorption, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis analysis, and photoluminescence (PL). The catalytic properties of composites were evaluated by photodegrading tetracycline hydrochloride (TC) under visible light irradiation. Among these catalysts, Bi2O2CO3(1.5)/g-C3N4 showed the highest catalytic activity, which was more than 16 times greater than the pristine g-C3N4 material. The improved photocatalytic properties of Bi2O2CO3/g-C3N4 may be due to the formation of a heterojunction between Bi2O2CO3 and g-C3N4, leading to the effective separation of photo-induced carriers and the enhanced absorption of visible light. Furthermore, the Bi2O2CO3/g-C3N4 composites had considerable catalytic stability, which was a key element for their potential applications.


Assuntos
Catálise , Grafite , Modelos Químicos , Luz , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
11.
Water Sci Technol ; 77(5-6): 1441-1448, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29528331

RESUMO

Novel visible-light-induced UiO-66/BiOI photocatalysts with a p-n junction structure have been prepared for the first time through a facile hydrothermal method. The prepared photocatalysts were characterized using the powder X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, UV-visible diffuse reflectance spectra, and N2 adsorption-desorption (Brunauer-Emmett-Teller) techniques respectively. The photodegradation performances of UiO-66/BiOI photocatalysts were evaluated by photodegrading salicylic acid under visible-light irradiation. The UiO-66/BiOI composites displayed much higher photocatalytic efficiencies than pure BiOI under visible light. When the content of UiO-66 was 5.2 wt%, the composite (UiO-66/BiOI-2) has the best photocatalytic activity. Most of the salicylic acid molecules can be degraded in 100 min. The degradation rate of UiO-66/BiOI-2 samples is higher than single BiOI and UiO-66. The enhanced photocatalytic performance of UiO-66/BiOI may be ascribed to the formation of p-n heterojunctions between BiOI and UiO-66, which facilitates the transfer and separation of the photogenerated charge carriers. After recycling of the photocatalyst for five times for the photodegradation of salicylic acid, more than 85% of salicylic acid could still be degraded in the fifth cycle, implying that the as-prepared photocatalysts are highly stable.


Assuntos
Bismuto/química , Luz , Zircônio/química , Adsorção , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Processos Fotoquímicos , Fotólise , Difração de Raios X
12.
Surg Endosc ; 31(9): 3628-3636, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28130585

RESUMO

BACKGROUND: This study aimed to determine the feasibility of the extracapsular enucleation method for giant liver hemangiomas by infrahepatic inferior vena cava (IVC) clamping and the Pringle maneuver to control intraoperative bleeding under laparoscopic hepatectomy. METHODS: From January 2012 to January 2016, 36 patients underwent laparoscopic extracapsular enucleation of giant liver hemangiomas. Patients were divided into two groups: infrahepatic IVC clamping + Pringle maneuvers group (IVCP group, n = 15) and the Pringle maneuvers group (Pringle group, n = 21). Operative parameters, postoperative laboratory tests, and morbidity and mortality were analyzed. RESULTS: The mean size of liver hemangiomas was 13.3 cm (range 10-25 cm). Infrahepatic IVC clamping + the Pringle maneuvers with laparoscopic extracapsular enucleation significantly reduced intraoperative blood loss (586.7 vs 315.3 mL, p < 0.001) and transfusion rates (23.8 vs 6.7%, p = 0.001), compared with the Pringle maneuver alone. The gallbladder was retained in both groups. The mean arterial pressure (MAP) in Pringle group remained virtually stable before and after clamping of hepatic portal, while it was significantly decreased after IVC clamping in IVCP group than that pre-clamping (p < 0.001). The heart rate of all patients was significantly increased after clamping when compared to pre-clamping heart rates (p < 0.001). Once vascular occlusion was released, MAP returned to normal levels within a few minutes. There were no significant differences in postoperative complications between two groups. The vascular occlusion techniques in both groups had no serious effect on postoperative of hepatic and renal function. CONCLUSIONS: Extracapsular enucleation with infrahepatic IVC clamping + the Pringle maneuver is a safe and effective surgical treatment to control bleeding for giant liver hemangiomas in laparoscopic hepatectomy.


Assuntos
Perda Sanguínea Cirúrgica/prevenção & controle , Hemangioma/cirurgia , Hemostasia Cirúrgica/métodos , Hepatectomia/métodos , Laparoscopia , Neoplasias Hepáticas/cirurgia , Veia Cava Inferior/cirurgia , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
13.
Hum Brain Mapp ; 36(1): 238-57, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25181023

RESUMO

The superior parietal lobule (SPL) plays a pivotal role in many cognitive, perceptive, and motor-related processes. This implies that a mosaic of distinct functional and structural subregions may exist in this area. Recent studies have demonstrated that the ongoing spontaneous fluctuations in the brain at rest are highly structured and, like coactivation patterns, reflect the integration of cortical locations into long-distance networks. This suggests that the internal differentiation of a complex brain region may be revealed by interaction patterns that are reflected in different neuroimaging modalities. On the basis of this perspective, we aimed to identify a convergent functional organization of the SPL using multimodal neuroimaging approaches. The SPL was first parcellated based on its structural connections as well as on its resting-state connectivity and coactivation patterns. Then, post hoc functional characterizations and connectivity analyses were performed for each subregion. The three types of connectivity-based parcellations consistently identified five subregions in the SPL of each hemisphere. The two anterior subregions were found to be primarily involved in action processes and in visually guided visuomotor functions, whereas the three posterior subregions were primarily associated with visual perception, spatial cognition, reasoning, working memory, and attention. This parcellation scheme for the SPL was further supported by revealing distinct connectivity patterns for each subregion in all the used modalities. These results thus indicate a convergent functional architecture of the SPL that can be revealed based on different types of connectivity and is reflected by different functions and interactions.


Assuntos
Mapeamento Encefálico , Vias Neurais/fisiologia , Neuroimagem , Lobo Parietal/fisiologia , Adolescente , Feminino , Humanos , Masculino , Rede Nervosa/irrigação sanguínea , Rede Nervosa/fisiologia , Vias Neurais/irrigação sanguínea , Lobo Parietal/irrigação sanguínea , Descanso , Adulto Jovem
14.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 32(1): 77-81, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-25997270

RESUMO

Focusing on the poor mechanical strength of porous bioceramics bone scaffold, and taking into account of the good mechanical properties of biodegradable magnesium alloy, we proposed a novel method to fabricate magnesium alloy/bioceramics composite bone scaffold with stereolithography double channels. Firstly, a scaffold structure without mutually connected double channels was designed. Then, an optimized bioceramics scaffold was fabricated according to stereolithography and gel-casing. Molten AZ31 magnesium alloy was perfused into the secondary channel of scaffold by low-pressure casting, and magnesium alloy/bioceramics composite bone scaffold was obtained when magnesium alloy was solidified. The compression test showed that the strength of bioceramics scaffold with only one channel and without magnesium alloy was (9.76 ± 0.64) MPa, while the strength of magnesium alloy/bioceramics composite scaffold with double channels was (17.25 ± 0.88) MPa. It can be concluded that the magnesium alloy/bioceramics composite is obviously able to improve the scaffold strength.


Assuntos
Osso e Ossos , Cerâmica , Teste de Materiais , Alicerces Teciduais , Ligas , Fenômenos Biomecânicos , Humanos , Magnésio , Porosidade
15.
Int J Mol Sci ; 15(3): 3507-18, 2014 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-24577313

RESUMO

Growing evidence has shown that hepatic oval cells, also named liver progenitor cells, play an important role in the process of liver regeneration in various liver diseases. Oval cell proliferation has been reported in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and chronic liver disease. Studies have found expression of HBV surface and core antigens in oval cells in the livers of patients with HCC, suggesting that HBV infection of oval cells could be a mechanism of human hepatocarcinogenesis. In addition, there is evidence of multiplication of HBV in oval cell culture. However, little research has been performed to explore the role of HBV-encoded proteins in the proliferation of hepatic oval cells. Previously, we successfully transfected the HBV x (HBx) gene, one of the four genes in the HBV genome, into a rat LE/6 oval cell line. In this study, we tested whether or not the transfected HBx gene could affect oval cell proliferation in vitro. Our results show that overexpression of HBx promotes the proliferation of oval cells and increases cyclin D1 expression, assessed at both the mRNA and protein levels. We also found that HBx activated the PI-3K/Akt and MEK/ERK1/2 pathways in HBx-transfected oval cells. Furthermore, the HBx-induced increases in cyclin D1 expression and oval cell proliferation were completely abolished by treatment with either MEK inhibitor PD184352 or PI-3K inhibitor LY294002. These results demonstrated that HBx has the ability to promote oval cell proliferation in vitro, and its stimulatory effects on cell proliferation and expression of cyclin D1 depend on the activation of the MEK/ERK and PI3K/Akt signaling pathways in cultured oval cells.


Assuntos
Ciclina D1/metabolismo , Fígado/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transativadores/metabolismo , Animais , Benzamidas/farmacologia , Western Blotting , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cromonas/farmacologia , Ciclina D1/genética , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Fígado/citologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transativadores/genética , Regulação para Cima , Proteínas Virais Reguladoras e Acessórias
16.
Mar Pollut Bull ; 202: 116361, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38636345

RESUMO

A variety of machine learning (ML) models have been extensively utilized in predicting biomass pyrolysis owing to their prowess in deciphering complex non-linear relationships between inputs and outputs, but there is still a lack of consensus on the optimal methods. This study elaborates on the development, optimization, and evaluation of three ML methodologies, namely, artificial neural networks, random forest (RF), and support vector machines, aimed to determine the optimal model for accurate prediction of biomass pyrolysis behavior using thermogravimetric data. This work assesses the utility of thermal data derived from these models in the computation of kinetic and thermodynamic parameters, alongside an analysis of their statistical performance. Eventually, the RF model exhibits superior physical interpretability and the least discrepancy in predicting kinetic and thermodynamic parameters. Furthermore, a feature importance analysis conducted within the RF model framework quantitatively reveals that temperature and heating rate account for 98.5 % and 1.5 %, respectively.


Assuntos
Biomassa , Aprendizado de Máquina , Redes Neurais de Computação , Pirólise , Termogravimetria , Máquina de Vetores de Suporte , Termodinâmica
17.
Hepatogastroenterology ; 60(121): 6-13, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23682386

RESUMO

BACKGROUND/AIMS: To investigate Omi/HtrA2 expression and its clinical significance in hepatocellular carcinoma. METHODOLOGY: We analyzed Omi/HtrA2 expression in hepatocellular carcinoma, paracancerous tissues and normal hepatic tissues by immunohistochemistry, RT-PCR and Western blot. Hypoxia-inducible factor-1α (HIF-1α) expression was also detected in hepatocellular carcinoma samples by immunohistochemistry. Meanwhile, we retrospectively analyzed the relationship between Omi/HtrA2 expression and the survival times of the patients. RESULTS: We found that Omi/HtrA2 overexpressed in hepatocellular carcinoma and was correlated with hepatocellular carcinoma differentiation, tumor size, portal vein invasion, clinical stage and lymph node metastasis. We also observed a significant inverse correlation between the expression of Omi,/HtrA2 and HIF-1α in hepatocellular carcinoma. The Kaplan-Meier estimates showed that patients who were Omi/HtrA2 positive had much longer survival times than those who were Omi/HtrA2 negative. Both univariate and multivariate analysis using the Cox regression model indicated that Omi/HtrA2 expression was a significant factor for prognosis. CONCLUSIONS: Hepatocellular carcinoma cells may need Omi/HtrA2 expression for apoptosis and Omi/HtrA2 might be an important prognostic marker for primary hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular/química , Neoplasias Hepáticas/química , Proteínas Mitocondriais/análise , Serina Endopeptidases/análise , Adolescente , Adulto , Idoso , Apoptose , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Pessoa de Meia-Idade , Proteínas Mitocondriais/fisiologia , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Serina Endopeptidases/fisiologia
18.
Oncol Res ; 20(5-6): 213-20, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23581228

RESUMO

Hypoxia-inducible factor-1alpha (HIF-1alpha) plays an important role in regulating hepatoma cell apoptosis. However, conclusions of different studies about the effects of HIF-1alpha expression on hepatoma cell apoptosis remain controversial. Omi/HtrA2 promotes cell apoptosis in some human cancer cells. Our previous experiments have demonstrated that primary hepatocellular carcinoma may need Omi/HtrA2 expression for cell apoptosis. Thus, we investigated the effect of HIF-1alpha on hepatocellular carcinoma cell apoptosis and Omi/ HtrA2 expression. In our study we found that HIF-1alpha gene could suppress hepatoma cell apoptosis, and Omi/HtrA2 mRNA and protein expression decreased with HIF-1alpha expression increase while Bcl-2 mRNA and protein expression increased with HIF-1alpha expression increase in HepG2 cells under normoxia condition. Meanwhile, Omi/HtrA2 protein expression increased with HIF-1alpha expression decrease in HepG2 cells under hypoxia culture. Taken together, these results demonstrated that HIF-1alpha suppressed hepatocellular carcinoma cell apoptosis through inhibiting Omi/HtrA2 expression and upregulating Bcl-2 expression to impede Omi/ HtrA2 releasing from the mitochondrion. The present finding further enriched and supported the role of HIF-1alpha expression on cell apoptosis of hepatoma cells.


Assuntos
Carcinoma Hepatocelular/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Mitocondriais/metabolismo , Serina Endopeptidases/metabolismo , Apoptose , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Hipóxia Celular , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Serina Endopeptidases/genética
19.
Zhonghua Wai Ke Za Zhi ; 50(1): 49-52, 2012 Jan 01.
Artigo em Chinês | MEDLINE | ID: mdl-22490291

RESUMO

OBJECTIVES: To investigate the prognostic significance of Omi/HtrA2 expression, and the correlation between Omi/HtrA2 and Hypoxia-inducible factor (HIF)-1α in primary hepatocellular carcinoma cells. METHODS: The expression of HIF-1α and Omi/HtrA2 in 43 cases of hepatic carcinoma tissues were detected immunohistochemically. Follow-up data were obtained to perform the Kaplan-Meier survival analysis. The change of Omi/HtrA2 expression in HepG2 cell was measured after HIF-1α expression of HepG2 in vitro was regulated by Tet-on expression system. RESULTS: Omi/HtrA2 expression was correlated with lymph node metastasis and recurring within liver during 2 years. Statistical analysis estimation showed the cumulative survival rate of post-hepatectomy for the patients with the positive expression of Omi/HtrA2 was higher than that for other patients with the negative expression of Omi/HtrA2 (χ(2) = 6.13, P = 0.013). In the common paraffin-embedded specimen of hepatocellular carcinoma, most of the samples showing negative or weak positive HIF-1α immunopositivity showed moderate positive or strong positive Omi/HtrA2 immunopositivity, while most of the samples showing moderate positive or strong positive HIF-1α immunopositivity showed negative or weak positive Omi/HtrA2 immunopositivity. The mRNA expression intensity of Omi/HtrA2 was decreasing with the HIF-1α expression increasing, and the difference was statistically significant(F = 106.766, P < 0.01). CONCLUSIONS: Omi/HtrA2 may be an important prognostic marker for primary hepatocellular carcinoma. Omi/HtrA2 expression is reversely correlated with HIF-1α expression in hepatocellular carcinoma. During the apoptotic process Omi/HtrA2 participating in hepatocellular carcinoma cells, HIF-1α is involved in the controlling and regulating of Omi/HtrA2 expression.


Assuntos
Carcinoma Hepatocelular/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Mitocondriais/metabolismo , Serina Endopeptidases/metabolismo , Adolescente , Adulto , Idoso , Carcinoma Hepatocelular/patologia , Feminino , Seguimentos , Células Hep G2 , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Prognóstico , Transfecção , Células Tumorais Cultivadas , Adulto Jovem
20.
Water Environ Res ; 83(9): 784-90, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22073725

RESUMO

Hydrated iron oxide supported on resin (D301) was prepared as a new sorbent for the removal of glyphosate from wastewater. Batch adsorption studies were performed on glyphosate aqueous solutions with different initial glyphosate concentrations and temperatures. Experimental data were analyzed using the Langmuir and Freundlich isotherms, and the adsorption data were best fit to the Langmuir isotherm model. The thermodynamic parameters AG, AH, and AS also were calculated for the adsorption processes. Adsorption rate constants were determined using the pseudo-first-order and pseudo-second-order rate equations and Kannan-Sundaram intraparticle diffusion models. Adsorption of glyphosate clearly followed the pseudo-second-order model and was controlled by both film diffusion and intraparticle diffusion.


Assuntos
Compostos Férricos/química , Glicina/análogos & derivados , Herbicidas/química , Água/química , Adsorção , Cromatografia Líquida de Alta Pressão , Glicina/química , Cinética , Microscopia Eletrônica de Varredura , Modelos Moleculares , Espectrofotometria Ultravioleta , Termodinâmica , Glifosato
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