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1.
BMC Ophthalmol ; 24(1): 329, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39112923

RESUMO

BACKGROUND: Considering that changes in the choroidal thickness are closely related to ocular growth, we studied the choroidal thickness (CT) and the blood flow features in children with unilateral myopic anisometropia (UMA) as well as investigating the relationship between choroidal changes and myopia. METHODS: Subjective refractive, axial length (AL), and biometric parameters were measured in 98 UMA children (age: 8-15 years). CT and choroidal blood-flow features, including the choroidal vessel volume (CVV), choroidal vascularity index (CVI), and choriocapillaris perfusion area (CCPA), were measured through swept-source optical coherence tomography angiography. The macular region was categorized into four concentric circles of diameters 0-1 mm (central fovea), 1-3 mm (parafovea), 3-6 mm (perifovea), and 6-9 mm (extended), and further categorized into superior (S), inferior (I), temporal (T), and nasal (N) quadrants. RESULTS: The aforementioned four regions of myopic eyes displayed significantly lower CT, CVV, and CVI than those of non-myopic eyes. CCPA changes differed across different regions of both the eyes (parts of N and T quadrants). There was an inverse association between CT and the interocular AL difference (central and other regions S, T quadrant). No correlation was noted between CVV and CVI with interocular AL difference. CT and CVV were positively correlated in the 0-6-mm macular region of myopic eyes (Spearman correlation coefficient = 0.763, P < 0.001). CONCLUSIONS: In UMA children, CCT and blood flow may be related to myopia progression. A robust correlation between CT and CVV in the 0-6-mm macular region and reduced CT and diminished blood flow indicated an association with myopia.


Assuntos
Anisometropia , Comprimento Axial do Olho , Corioide , Miopia , Fluxo Sanguíneo Regional , Tomografia de Coerência Óptica , Humanos , Corioide/irrigação sanguínea , Corioide/patologia , Corioide/diagnóstico por imagem , Criança , Adolescente , Masculino , Feminino , Anisometropia/fisiopatologia , Miopia/fisiopatologia , Tomografia de Coerência Óptica/métodos , Comprimento Axial do Olho/patologia , Fluxo Sanguíneo Regional/fisiologia , Refração Ocular/fisiologia , Angiofluoresceinografia/métodos
2.
BMC Vet Res ; 12(1): 237, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27765059

RESUMO

BACKGROUND: The neonatal Fc receptor (FcRn) plays a crucial role in transporting IgG and associated antigens across polarized epithelial barriers in mucosal immunity. However, it was not clear that FcRn expression in aggregated lymphoid nodules area (ALNA) in abomasum, a unique and important mucosal immune structure discovered only in Bactrian camels. In the present study, 27 Alashan Bactrian camels were divided into the following five age groups: fetus (10-13 months of gestation), young (1-2 years), pubertal (3-5 years), middle-aged (6-16 years) and old (17-20 years). The FcRn expressions were observed and analyzed in detail with histology, immunohistochemistry, micro-image analysis and statistical methods. RESULTS: The results showed that the FcRn was expressed in mucosal epithelial cells of ALNA from the fetus to the old group, although the expression level rapidly declined in old group; moreover, after the ALNA maturated, the FcRn expression level in the non-follicle-associated epithelium (non-FAE) was significantly higher than that in FAE (P < 0.05). In addition, the FcRn was also expressed in the vessel endothelium, smooth muscle tissue, and macrophages and dendritic cells (DCs) of secondary lymphoid follicles (sLFs). CONCLUSIONS: It was demonstrated that FcRn was mainly expressed in non-FAE, the effector sites, although which was expressed in FAE, the inductive sites for mucosal immunity. And it was also expressed in DCs and macrophages in sLFs of all ages of Bactrian camels. The results provided a powerful evidence that IgG (including HCAb) could participate in mucosal immune response and tolerance in ALNA of Bactrian camels through FcRn transmembrane transport.


Assuntos
Abomaso/imunologia , Camelus/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Imunidade nas Mucosas/imunologia , Imunoglobulina G/metabolismo , Tecido Linfoide/imunologia , Receptores Fc/genética , Receptores Fc/imunologia , Abomaso/metabolismo , Fatores Etários , Animais , Camelus/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/metabolismo , Imunidade nas Mucosas/genética , Tecido Linfoide/metabolismo , Receptores Fc/metabolismo
3.
Biochim Biophys Acta Mol Basis Dis ; : 167493, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39233261

RESUMO

The immune landscape of distant unablated tumors following insufficient microwave ablation (iMWA) in hepatocellular carcinoma (HCC) remains to be clarified. The objective of this study is to define the abscopal immune landscape in distant unablated tumor before and after iMWA for HCC. Two treatment-naive patients were recruited for tumor tissue sampling, of each with two HCC lesions. Tumor samples were obtained at before and after microwave ablation in distant unablated sites for single-cell RNA sequencing (scRNA-seq). Mouse model with bilateral hepatoma tumors were developed, and distant unablated tumors were analyzed using multicolor immunofluorescence, RNA sequencing and flow cytometry. The scRNA-seq revealed that a reduced proportion of CD8+ T cells and an increased proportion of myeloid-derived suppressor cells (MDSCs) were observed in the distant unablated tumor microenvironment (TME). A notable disruption was observed in the lipid metabolism of tumor-associated immune cells, accompanied by an upregulated expression of CD36 in tumor-infiltrating immune cells in distant unablated tumor. The administration of a CD36 inhibitor has been demonstrated to ameliorate the adverse effects induced by iMWA, primarily by reinstating the anti-tumor responses of T cells in distant unablated tumor. These findings explain the recurrence and progression of tumors after iMWA and provide a new target of immunotherapy for HCC.

5.
World J Pediatr ; 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39143259

RESUMO

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is a significant contributor to community-acquired pneumonia among children. Since 1968, when a strain of M. pneumoniae resistant to macrolide antibiotics was initially reported in Japan, macrolide-resistant M. pneumoniae (MRMP) has been documented in many countries worldwide, with varying incidence rates. MRMP infections lead to a poor response to macrolide antibiotics, frequently resulting in prolonged fever, extended antibiotic treatment, increased hospitalization, intensive care unit admissions, and a significantly higher proportion of patients receiving glucocorticoids or second-line antibiotics. Since 2000, the global incidence of MRMP has gradually increased, especially in East Asia, which has posed a serious challenge to the treatment of M. pneumoniae infections in children and attracted widespread attention from pediatricians. However, there is still no global consensus on the diagnosis and treatment of MRMP in children. METHODS: We organized 29 Chinese experts majoring in pediatric pulmonology and epidemiology to write the world's first consensus on the diagnosis and treatment of pediatric MRMP pneumonia, based on evidence collection. The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, CNKI, Medline, and the Cochrane Library. We used variations in terms for "macrolide-resistant", "Mycoplasma pneumoniae", "MP", "M. pneumoniae", "pneumonia", "MRMP", "lower respiratory tract infection", "Mycoplasma pneumoniae infection", "children", and "pediatric". RESULTS: Epidemiology, pathogenesis, clinical manifestations, early identification, laboratory examination, principles of antibiotic use, application of glucocorticoids and intravenous immunoglobulin, and precautions for bronchoscopy are highlighted. Early and rapid identification of gene mutations associated with MRMP is now available by polymerase chain reaction and fluorescent probe techniques in respiratory specimens. Although the resistance rate to macrolide remains high, it is fortunate that M. pneumoniae still maintains good in vitro sensitivity to second-line antibiotics such as tetracyclines and quinolones, making them an effective treatment option for patients with initial treatment failure caused by macrolide antibiotics. CONCLUSIONS: This consensus, based on international and national scientific evidence, provides scientific guidance for the diagnosis and treatment of MRMP in children. Further studies on tetracycline and quinolone drugs in children are urgently needed to evaluate their effects on the growth and development. Additionally, developing an antibiotic rotation treatment strategy is necessary to reduce the prevalence of MRMP strains.

6.
J Oleo Sci ; 72(4): 389-397, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36908178

RESUMO

The objective of this study was to characterize the lipid class and fatty acid composition of four kinds of marine oils including Phaeodactylum tricornutum oil (PO), Laminaria japonica oil (LO), krill oil (KO) and fish oil (FO), and evaluate their antioxidant capacities in vitro. The results indicated that compared to other three oils, PO showed the highest contents of total lipids and fucoxanthin (194.70 and 7.48 mg/g dry weight, respectively), the relatively higher content of long-chain polyunsaturated fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (30.94 % in total fatty acids), and total phenolic content (675.88 mg gallic acid equivalent /100 g lipids), thereby contribute to great advantages in scavenging free radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS), peroxyl radical, as well as reducing FRAP value. In conclusion, PO should be considered as a potential ingredient for dietary supplement with antioxidant capacity.


Assuntos
Antioxidantes , Óleos de Peixe , Antioxidantes/farmacologia , Óleos de Peixe/química , Ácido Eicosapentaenoico , Ácidos Graxos , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos
7.
Biomedicines ; 11(8)2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37626693

RESUMO

To improve the survival of patients with hepatocellular carcinoma (HCC), new biomarkers and therapeutic targets are urgently needed. In this study, the GEO and TCGA dataset were used to explore the differential co-expressed genes and their prognostic correlation between HCC and normal samples. The mRNA levels of these genes were validated by qRT-PCR in 20 paired fresh HCC samples. The results demonstrated that the eight-gene model was effective in predicting the prognosis of HCC patients in the validation cohorts. Based on qRT-PCR results, NOX4 was selected to further explore biological functions within the model and 150 cases of paraffin-embedded HCC tissues were scored for NOX4 immunohistochemical staining. We found that the NOX4 expression was significantly upregulated in HCC and was associated with poor survival. In terms of function, the knockdown of NOX4 markedly inhibited the progression of HCC in vivo and in vitro. Mechanistic studies suggested that NOX4 promotes HCC progression through the activation of the epithelial-mesenchymal transition. In addition, the sensitivity of HCC cells to sorafenib treatment was obviously decreased after NOX4 overexpression. Taken together, this study reveals NOX4 as a potential therapeutic target for HCC and a biomarker for predicting the sorafenib treatment response.

8.
Front Cell Neurosci ; 16: 878673, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35573833

RESUMO

Cell apoptosis plays an important role in early brain injury (EBI) after subarachnoid hemorrhage (SAH). Heat shock protein 27 (HSP27), a member of the small heat shock protein (HSP) family, is induced by various stress factors and exerts protective role on cells. However, the role of HSP27 in brain injury after SAH needs to be further clarified. Here, we reported that HSP27 level of cerebrospinal fluid (CSF) is increased obviously at day 1 in patients with aneurysmal SAH (aSAH) and related to the grades of Hunt and Hess (HH), World Federation of Neurological Surgeons (WFNS), and Fisher score. In rat SAH model, HSP27 of CSF is first increased and then obviously declined; overexpression of HSP27, not knockdown of HSP27, attenuates SAH-induced neurological deficit and cell apoptosis in the basal cortex; and overexpression of HSP27 effectively suppresses SAH-elevated activation of mitogen-activated protein Kinase Kinase 4 (MKK4), the c-Jun N-terminal kinase (JNK), c-Jun, and caspase-3. In an in vitro hemolysate-damaged cortical neuron model, HSP2765-90 peptide effectively inhibits hemolysate-induced neuron death. Furthermore, TAT-HSP2765-90 peptide, a fusion peptide consisting of trans-activating regulatory protein (TAT) of HIV and HSP2765-90 peptide, effectively attenuates SAH-induced neurological deficit and cell apoptosis in the basal cortex of rats. Altogether, our results suggest that TAT-HSP27 peptide improves neurologic deficits via reducing apoptosis.

9.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 5): o1206, 2011 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754505

RESUMO

In the mol-ecule of the title compound, C(16)H(19)N(3)O(6), the imidazole ring is essentially planar [maximum deviation = 0.002 (2) Å] and forms a dihedral angle of 5.08 (14)° with the nitro group. In the crystal structure, adjacent mol-ecules are connected via inter-molecular C-H⋯O hydrogen bonds into columns parallel to the a axis.

10.
Zhong Yao Cai ; 34(7): 1078-80, 2011 Jul.
Artigo em Zh | MEDLINE | ID: mdl-22066403

RESUMO

OBJECTIVE: To screen the antithrombotic active fraction of Naodesheng. METHODS: The collagen and adrenaline-induced thrombosis by tail intravenous injection in mice was used. Based on orthogonal design, the support vector machine model was established for pharmacodynamics prediction of TCM prescriptions. RESULTS: The model established in this study could predict the drug actions of different combinations. CONCLUSION: The pharmacodynamic actions of several formulas are superior to that of the original formula and CD has the best effect.


Assuntos
Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Fibrinolíticos/química , Fibrinolíticos/farmacologia , Máquina de Vetores de Suporte , Trombose/tratamento farmacológico , Algoritmos , Animais , Fracionamento Químico , Simulação por Computador , Combinação de Medicamentos , Descoberta de Drogas/métodos , Medicamentos de Ervas Chinesas/isolamento & purificação , Feminino , Fibrinolíticos/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos , Modelos Estatísticos , Plantas Medicinais/química , Distribuição Aleatória , Relação Estrutura-Atividade , Trombose/induzido quimicamente
11.
Vet Sci ; 8(12)2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34941846

RESUMO

Staphylococci are the most common pathogens isolated from skin infections in livestock or companion animals. Antibiotic therapy is the best treatment for infections, but local or systemic use of antimicrobials increases the risk of bacterial resistance. Insects are rich in antimicrobial peptides, which can reduce bacterial resistance and can be used to treat bacterial infections after skin burns. We propose that the use of the darkling beetle (Z. morio) hemolymph to treat skin infections in mice by Staphylococcus haemolyticus is one of the alternatives. Z. morio hemolymph alleviated the increase in wound area temperature in mice with a skin infection, reduced the bacterial load of the wound, and accelerated the wound healing speed significantly. Pathological sections showed that Z. morio hemolymph can significantly reduce inflammatory cell infiltration, and promote skin tissue repair. Real-time fluorescent quantitative polymerase chain reaction (PCR) revealed that the Z. morio hemolymph can significantly reduce the levels of pro-inflammatory cytokines, including interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and chemokine interleukin-8 (IL-8). Our findings suggest that Z. morio antibacterial hemolymph can promote wound contraction, relieve local inflammatory responses and promote wound healing in mice infected with a heat injury, which has a positive therapeutic effect and enormous potential for skin thermal injury.

12.
Front Pharmacol ; 12: 719589, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34434111

RESUMO

Long-term exposure to crystalline silica particles leads to silicosis characterized by persistent inflammation and progressive fibrosis in the lung. So far, there is no specific treatment to cure the disease other than supportive care. In this study, we examined the effects of metformin, a prescribed drug for type || diabetes on silicosis and explored the possible mechanisms in an established rat silicosis model in vivo, and an in vitro co-cultured model containing human macrophages cells (THP-1) and human bronchial epithelial cells (HBEC). Our results showed that metformin significantly alleviated the inflammation and fibrosis of lung tissues of rats exposed to silica particles. Metformin significantly reduced silica particle-induced inflammatory cytokines including transforming growth factor-ß1 (TGF-ß1), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in rat lung tissue and HBEC culture supernatant. The protein levels of Vimentin and α-smooth muscle actin (α-SMA) were significantly decreased by metfomin while expression level of E-cadherin (E-Cad) increased. Besides, metformin increased the expression levels of phosphorylated adenosine 5'-monophosphate (AMP)-activated protein kinase (p-AMPK), microtubule-associated protein (MAP) light chain 3B (LC3B) and Beclin1 proteins, and reduced levels of phosphorylated mammalian target of rapamycin (p-mTOR) and p62 proteins in vivo and in vitro. These results suggest that metformin could inhibit silica-induced pulmonary fibrosis by activating autophagy through the AMPK-mTOR pathway.

13.
J Asian Nat Prod Res ; 12(4): 331-3, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20419545

RESUMO

A new alkaloid (1), together with five known compounds (2-6), has been isolated from the stem of Sparganium stoloniferum Buch.-Ham. The structure of the new compound was elucidated as 3-isobutyl-tetrahydro-imidazo[1,2-a]pyridine-2,5-dione on the basis of physical and chemical evidence and spectral analysis. Compound 6 was obtained for the first time from the Sparganium genus.


Assuntos
Alcaloides/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Magnoliopsida/química , Piridonas/isolamento & purificação , Alcaloides/química , Medicamentos de Ervas Chinesas/química , Estrutura Molecular , Caules de Planta/química , Piridonas/química
14.
Int J Biol Macromol ; 132: 836-843, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30926494

RESUMO

Valorization of lignin by-product is an urgent issue in the context of biorefinery. Lignin is a natural anti-UV active ingredient with great potential applications. In this study, a natural broad-spectrum photo-protection agent was prepared using lignin from organic acid extraction process. The submicrometer particles were prepared by dialysis lignin recovered from the pretreatments with organic acid extraction processes (formic acid, formic acid/hydrogen peroxide, and acetic acid/hydrogen peroxide/HCl) and they served as active ingredients in sunblock formulation. The structures of the lignin submicrometer particles were characterized by multiple spectroscopies. The submicrometer particles from organic acid lignin showed high capacities to enhance the sun protection factor values of lotion by 2.80-3.53 at the dosage of 5%, and the lotions containing lignin submicrometer particles had good UV-blocking properties. In addition, the UVA/UVB values (i.e., the ratio of absorbance at UVA to that at UVB) were in the range of 0.69-0.72 for the organic acid lignin submicrometer particles, indicating that they exhibited superior properties. The results indicated that the lignin submicrometer-based lotions with excellent antioxidant and UV protection capacities offered a natural source for sunblock cosmetics.


Assuntos
Produtos Biológicos/química , Formiatos/química , Sequestradores de Radicais Livres/química , Lignina/química , Protetores Solares/química , Compostos de Bifenilo/química , Tamanho da Partícula , Picratos/química , Raios Ultravioleta
15.
Sci Rep ; 9(1): 313, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670728

RESUMO

Increase in grain nitrogen concentration (GNC), which is directly affected by nitrogen (N) application, can help overcome the issues of malnutrition. Here, the effects of urea type (polyaspartic acid (PASP) urea and conventional urea) and N management method (two splits and four splits) on GNC and N concentration of head rice were investigated in field experiments conducted in Sichuan, China, in 2014 and 2015. N concentration of grain and head rice were significantly (P < 0.05) increased by N redistribution from the leaf lamina, activities of glutamine synthetase (GS), and glutamate synthase (GOGAT) at the heading stage, and N concentration and GOGAT activity in the leaf lamina at the maturity stage. Compared to conventional urea, PASP-urea significantly improved N concentration of grain and head rice by improving the activities of GS and GOGAT, thereby increasing N distribution in the leaf lamina. The four splits method, unlike the two splits method, enhanced N concentration and activities of key N metabolism enzymes of leaf lamina, leading to increased GNC and N concentration in head rice too. Overall, four splits is a feasible method for using PASP-urea and improving GNC.


Assuntos
Grão Comestível/metabolismo , Nitrogênio/metabolismo , Oryza/metabolismo , China , Glutamato Sintase/metabolismo , Glutamato-Amônia Ligase/metabolismo , Peptídeos/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Ureia/metabolismo
16.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 9): o1690, 2008 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-21201679

RESUMO

In the crystal structure, the title compound, C(12)H(16)N(6)O(6), lies on an inversion centre. The mol-ecule has an anti-periplanar conformation with respect to the C-C bond of the central ethane unit and the two imidazole rings are parallel to each other. The dihedral angle between the imidazole ring and the mean plane of the C and O atoms of the bis-(eth-oxy)ethane group is 76.04 (6)°. The mol-ecules are stacked along the c axis through a weak C-H⋯O inter-action and a π⋯π inter-action between the imidazole rings with a centroid-centroid distance of 3.5162 (6) Å. An intramolecular C-H⋯O hydrogen bond is also present.

17.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 8): o1409, 2008 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21203129

RESUMO

In the crystal structure of the title compound, C(20)H(16)O(4), the naphthalene ring system makes dihedral angles of 43.79 (7) and 83.70 (9)°, respectively, with the mean planes of the phenyl ring and the acetate unit. C-H⋯π inter-actions involving all the aromatic six-membered rings are observed. The mol-ecules are stacked into columns along the a axis and adjacent columns are linked by weak C-H⋯O inter-actions.

18.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 8): o1474-5, 2008 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-21203187

RESUMO

In the title mol-ecule (systematic name: methane-tetra-yltetra-methyl-ene tetra-p-toluene-sulfonate), C(33)H(36)O(12)S(4), the central C atom and the S atoms exhibit distorted tetra-hedral configurations. The aromatic rings in opposite arms are nearly parallel to each other, with a dihedral angle of 10.26 (8) or 3.45 (9)°. The mol-ecules are linked into a two-dimensional network parallel to the bc plane by weak C-H⋯O hydrogen bonds, π-π [centroid-centroid distance = 3.5806 (12) Å] and S-O⋯π [O⋯centroid = 3.1455 (15) Šand S-O⋯centroid = 122.41 (7)°] inter-molecular inter-actions. Intramolecular C-H⋯O hydrogen bonds are also present.

19.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 8): o1472-3, 2008 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-21203186

RESUMO

IN THE TITLE COMPOUND [SYSTEMATIC NAME: (tert-butyl-dimethyl-silyl)methane-triyl tris-(4-methyl-benzene-sulfonate)], C(32)H(44)O(10)S(3)Si, the central C atom and the Si(IV) center are in a tetra-hedral configuration. The inter-planar angles between pairs of the three benzene rings of the 4-methyl-phenyl-sulfonyl units are 41.15 (10), 18.11 (10) and 44.09 (10)°. C-H⋯π inter-actions are observed in the crystal structure. Mol-ecules are linked into screw chains along the b axis by weak C-H⋯O inter-actions. Weak intramolecular C-H⋯O hydrogen bonds are also present.

20.
Bioresour Technol ; 249: 348-353, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29054066

RESUMO

Corncob was torrefied under nitrogen and carbon dioxide atmospheres at 220-300 °C, obtaining solid products with mass yields of 69.38-95.03% and 67.20-94.99% and higher heating values of 16.58-24.77 MJ/kg and 16.68-24.10 MJ/kg, respectively. The changes of physicochemical properties of the charcoal was evaluated by many spectroscopies, contact angle determination, and combustion test. Hemicelluloses were not detected for the torrefaction under the hard conditions. As the severity increased, C concentration raised while H and O concentrations reduced. Combustion test showed that the burnout temperature of charcoal declined with the elevation of reaction temperature, and torrefaction at a high temperature shortened the time for the whole combustion process. Base on the data, torrefaction at 260 °C under carbon dioxide was recommended for the torrefaction of corncob.


Assuntos
Dióxido de Carbono , Carvão Vegetal , Nitrogênio , Atmosfera , Biomassa , Temperatura
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