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1.
Materials (Basel) ; 16(18)2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37763400

RESUMO

By experimental methods, 26 specimens were designed to conduct elastic and elastic-plastic buckling tests on cylindrical shells containing cracks. This study discusses the influence of factors such as the length-diameter ratio, the diameter-thickness ratio, the crack length, the inclination of the crack, etc., on the buckling load. Additionally, finite element models were established to compare with experimental results. For the PMMA cylindrical shell, the results showed that as the length-diameter ratio of the cylindrical shell increased, the buckling load first decreased and then increased. For the 6063 aluminum alloy cylindrical shell, with increasing length-diameter ratio, diameter-thickness ratio, and crack length of the cylindrical shell, the buckling load decreased accordingly. However, concerning the crack inclination, as the crack inclination increased, the buckling load increased accordingly. This indicates that the larger the crack inclination, the higher the load capacity of the cylindrical shell containing cracks. Through finite element simulations of cylindrical shells with cracks, it was found that through compressive mechanical properties, both elastic and elastic-plastic buckling loads yielded results that are closer to the experimental results. Additionally, the inclusion of contact effects in numerical simulations further improved the agreement with the experimental results, and the variation trend of the buckling load in the finite element simulation was consistent with the experimental results. The research findings provide valuable references for the assessment of load capacity in structures containing cracks.

2.
Food Chem ; 388: 133059, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35483294

RESUMO

To investigate the effects of ultrasonic treatment on proteolysis and taste development of defective dry-cured ham, sensory attributes, enzyme activities, protein degradation and free amino acids were evaluated after different ultrasonic treatments. The ultrasonic treatment of 1000 W & 50 °C significantly increased the intensities of overall taste, umami, sweetness and richness, and decreased bitterness values compared with other groups. The residual activities of DPP I and cathepsin B + L in 1000 W & 50 °C maintained 48.71% and 24.94% of control group, respectively; the intense degradation of structural proteins was observed by label-free proteomics, accordingly. The contents of total free amino acids from 4522.64 mg/100 g muscles in control group increased to 5838.75 mg/100 g muscles in 1000 W & 50 °C; the largest increase of sweet and umami amino acids observed in 1000 W & 50 °C was responsible for the improvement of taste quality of defective dry-cured ham.


Assuntos
Produtos da Carne , Carne de Porco , Aminoácidos , Manipulação de Alimentos , Produtos da Carne/análise , Proteólise , Paladar , Ultrassom
3.
Materials (Basel) ; 15(5)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35269157

RESUMO

Investigations on the fatigue crack growth of commercial pure titanium are carried out with cruciform specimens under different biaxial load ratios (λ = 0, 0.5, and 1) and crack inclination angles (ß = 90°, 60°, and 45°) in this paper. Based on the finite element results, the modified solution of stress intensity factors KI and KII for cruciform specimens containing mixed mode I-II crack is obtained by considering crack size, biaxial load ratio, and crack inclination angles. The experimental results show that the maximum tangential stress criterion is fit for the prediction of crack initiation angles for mixed model I-II crack under uniaxial or biaxial loading condition. When the biaxial load ratio increases, the crack propagation angle becomes smaller, and so does the fatigue crack growth rate of mode I crack or mixed mode I-II crack. Based on an equivalent stress intensity factor, a new valid stress intensity factor is proposed to better describe the biaxial fatigue crack growth behavior, which can demonstrate the contribution of mode I and mode II of stress intensity factor.

4.
Materials (Basel) ; 16(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36614703

RESUMO

Based on fracture mechanics theory, a finite element method was used to determine the stress intensity factors of the inclined crack on the inner surface of the pipe under axial compression load and external pressure. The effects of different influencing factors on the stress intensity factor along the crack front considering crack closure were systematically explored, which were different to those under internal pressure. The effects of high aspect ratio on KII, the crack inclination asymmetry caused by curvature and the effects of the friction coefficient on the stress intensity factors of the pipe with an inclined inner surface crack under axial compression load and external pressure were explored in this paper. To be fit for defect assessment, the solutions for stress intensity factors KII and KIII were derived, and new correction factors fθ and fµ were proposed in the empirical solutions to accommodate the crack inclination asymmetry and the friction coefficient, respectively.

5.
Compr Rev Food Sci Food Saf ; 20(4): 3838-3857, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34118135

RESUMO

Excessive bitterness, pastiness, and adhesiveness are the main organoleptic and textural defects of dry-cured ham, which often cause a lot of financial losses to manufacturers and seriously damage the quality of the product. These sensory and textural defects are related to the protein degradation of dry-cured ham. Proteomics shows great potential to improve our understanding of the molecular mechanism of sensory and textural defects and identify biomarkers for monitoring their quality traits. This review presents some of the major achievements and considerations in organoleptic and textural defects of dry-cured ham by proteomics analysis in the recent decades and gives an overview about how to correct sensory and textural defects of dry-cured ham. Proteomics reveals that muscle proteins derived from myofibril and cytoskeleton and involved in metabolic enzymes and oxygen transport have been identified as potential biomarkers in defective dry-cured ham. Relatively high residual activities of cathepsin B and L are responsible for the excessive degradation of these protein biomarkers in defective dry-cured ham. Ultrasound-assisted mild thermal or high-pressure treatment shows a good correction for the organoleptic and textural defects of dry-cured ham by changing microstructure and conformation of muscle proteins by accelerating degradation of proteins and polypeptides into free amino acids.


Assuntos
Produtos da Carne , Carne de Porco , Adesividade , Produtos da Carne/análise , Proteínas Musculares , Proteômica
6.
World J Clin Cases ; 9(1): 224-231, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33511189

RESUMO

BACKGROUND: Adult-onset Still's disease (AOSD) typically presents with a high spiking fever, polyarthritis, transient maculopapular rash, neutrophilic leukocytosis, and hepatosplenomegaly. It has a wide spectrum of clinical symptoms ranging from mild to severe, with extensive involvement of almost every organ. Although liver involvement in the form of increased hepatic enzymes and bilirubin is common, no AOSD case with liver involvement as the initial manifestation of AOSD has been reported. CASE SUMMARY: A 35-year-old woman presented to the hepatology department with progressively worsening jaundice for one week. Liver chemistry tests revealed a significantly increased liver enzymes and bilirubin level. Given that the clinical examination was unremarkable, liver biopsy was considered because the patient had a history of AOSD 6 years ago. Liver histopathology revealed that most hepatic lobules were still recognizable. Fusional necrosis was observed around most central veins. A few bridging necrotic zones were also found. Infiltration of multiple plasma cells were observed in the necrotic zone, and the reticular scaffold was still expanded. Additionally, no obvious fibrosis was observed in the portal area. Mild mixed inflammatory cell infiltration was noted in the interstitium of the portal area. Further examination was unremarkable except for a remarkably high level of ferritin. Collectively, a presumptive diagnosis of liver injury secondary to AOSD was made. The hepatic involvement responded well to glucocorticoid treatment. CONCLUSION: This case highlights that hepatic involvement as an initial and sole manifestation could be a pattern of relapsed AOSD. The diagnosis of AOSD should be considered in the case of nonresolving liver injury after the exclusion of common etiologies for liver diseases. A liver biopsy can be useful for the differential diagnosis of liver injury associated with AOSD.

7.
J Texture Stud ; 52(2): 207-218, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33368297

RESUMO

This study evaluated the texture of hog maw and the degradation of Types I and III collagen in the intramuscular connective tissue (IMCT) of hog maw at different cooking temperatures (75-95°C) and times (50-130 min). The cooking loss, shear force, collagen content, collagen solubility, and IMCT strength of hog maw cooked in water baths were measured. The instrumental texture profile analysis showed that the brittleness, springiness, chewiness and hardness of the cooked hog maw significantly increased with the increase of cooking temperature, while the hardness, springiness and chewiness increased first and then decreased with increasing cooking time. Cooking loss exhibited a 38% increase between the raw meat and meat cooked at 95°C. The collagen solubility significantly increased from 5.5 mg/g for raw meat to 8.6 mg/g for meat cooked at 95°C, accompanied by decreases in the shear force and IMCT strength associated with the increase in cooking temperature and time. These results show that the texture and collagen characteristics of hog maw are dramatically affected by the cooking temperature and time. Sodium dodecyl sulfate electrophoresis and immunofluorescence staining further showed that collagen degradation occurred after cooking, and the degradation of Type I collagen was higher than that of Type III collagen. These results indicated that the degradation of Type I collagen was mainly responsible for the sensory and textural improvements of the cooked hog maw.


Assuntos
Culinária , Carne , Colágeno , Dureza , Carne/análise , Suínos , Temperatura
8.
Neoplasma ; 68(1): 200-207, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32940044

RESUMO

Analysis of the value of long-term antiviral therapy using sequential Peg-IFN therapy and nucleos(t)ide analogues (NAs) improves the prognosis of HBV-related HCC. HBV-related HCC patients were classified into sequential therapy with Peg-IFNα-2a and NAs, and NAs therapy alone. All patients were followed up for 5 years. The survival rate, HCC recurrence rate, Child-Pugh score, and side effects of drugs were evaluated. Firstly, the early and late cumulative survival rate was higher in patients receiving antiviral therapy compared with the control patients (p<0.05). Patients receiving sequential therapy with Peg-IFNα-2a and NAs showed a higher late cumulative survival rate and significantly reduced early and late recurrence rate, compared to those in the NA-alone group (p<0.05). Single NAs therapy only reduced the late recurrence rate in HCC-patients. Secondly, NAs therapy significantly increased the Child-Pugh score after five years of therapy (five-year therapy 7.03±1.50 vs. initial score 6.63±0.85; p<0.05), whereas the sequential therapy with Peg-IFNα-2a and NAs did not greatly alter the Child-Pugh score (6.88±1.26; p>0.05). Compared to the control patients, patients receiving antiviral therapy (NAs alone or sequential therapy with Peg-IFNα-2a and NAs) exhibited a significantly decreased Child-Pugh score (p<0.05). Compared to NAs alone, sequential therapy with Peg-IFNα-2a and NAs provided a more efficient strategy for improving both the five-year survival rate and the two-year or five-year recurrence rate in patients.


Assuntos
Antivirais , Carcinoma Hepatocelular , Vírus da Hepatite B , Hepatite B , Interferon-alfa , Neoplasias Hepáticas , Nucleosídeos , Polietilenoglicóis , Antivirais/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Hepatite B/tratamento farmacológico , Hepatite B/patologia , Humanos , Interferon-alfa/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Recidiva Local de Neoplasia , Nucleosídeos/administração & dosagem , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Proteínas Recombinantes/administração & dosagem , Resultado do Tratamento
9.
World J Clin Cases ; 8(16): 3573-3577, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32913866

RESUMO

BACKGROUND: Spontaneous pneumomediastinum (SPM) is more common in young adults, usually caused by external factors like trauma. It causes symptoms such as chest pain or dyspnea, but it is rare to see elderly patients who develop SPM. Here we report the case of an elderly patient diagnosed with coronavirus disease 2019 (COVID-19) who neither got mechanical ventilation nor had chest trauma but were found to develop SPM for unknown reason. CASE SUMMARY: A 62-year-old man complained of a 14-d history of fever accompanied by dry cough, shortness of breath, wheezing, myalgia, nausea, and vomiting. Real-time fluorescence polymerase chain reaction confirmed the diagnosis of COVID-19. The patient was treated with supplementary oxygen by nasal cannula and gamma globulin. Other symptomatic treatments included antibacterial and antiviral treatments. On day 4 of hospitalization, he reported sudden onset of dyspnea. On day 6, he was somnolent. On day 12, the patient reported worsening right-sided chest pain which eventually progressed to bilateral chest pain. He was diagnosed with SPM, with no clear trigger found. Conservative treatment was administrated. During follow-up, the pneumomediastinum had resolved and the patient recovered without other complications. CONCLUSION: We presume that aging lung changes and bronchopulmonary infection play an important part in the onset of SPM in COVID-19, but severe acute respiratory syndrome may represent a separate pathophysiologic mechanism for pneumomediastinum. Although the incidence of SPM in elderly patients is low, clinicians should be alert to the possibility of SPM in those infected with severe acute respiratory syndrome coronavirus 2 for life-threatening complications such as cardiorespiratory arrest may occur.

10.
Food Chem ; 315: 126318, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32035317

RESUMO

To better understand the contribution of myosin light chain (MLC) isoforms to sensory defects in Jinhua ham, dipeptidyl peptidase (DPP) activities, peptide fragments, cleavage sites and the potential of DPP to develop sensory defects of dry-cured ham were evaluated and discussed in normal and defective hams. Higher residual activities of DPP I were found in defective ham compared with normal ham; approximate 3-fold peptide fragments were identified in defective ham than in normal ham. These regions of positions 11-35 and 116-141 in MLC 1, 13-53 and 139-156 in MLC 2, and 18-50 in MLC 3 contributed to the intense generation of peptide fragments in defective ham. PLS-DA further revealed DPP I showing intense response to degrade peptides. Cleavage sites including Glu-128, Tyr-132 and Glu-133 were responsible for the intense release of dipeptides in defective ham. These cleavages could play key role in discriminating taste attributes between defective and normal hams.


Assuntos
Produtos da Carne/análise , Cadeias Leves de Miosina/química , Carne de Porco/análise , Animais , Cadeias Leves de Miosina/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Proteólise , Suínos
11.
J Drug Target ; 28(1): 80-91, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31092059

RESUMO

This study aimed to investigate the effect of miR-206 on apoptosis and autophagy of cardiomyocytes in ischaemia/reperfusion (I/R) injured rats treated with sevoflurane post-conditioning (SP) through the AMPK/Nampt signalling pathway. Rat models of myocardial I/R injury were established. The combination of SP, miR-206 inhibitor, AMPK activator AICAR and inhibitor Compound C was induced in rats, and their effects on I/R injury were determined with detection of malondialdehyde (MDA), hydroxyproline (HYP) and superoxide dismutase (SOD) levels in cardiomyocytes, autophagy, and apoptosis. We also conducted experiments to determine p62, Beclin1, Bax and Bcl-2 expression and the mRNA and expression pattern of AMPK/Nampt signalling pathway-related genes. Myocardial I/R injured rats revealed decreased SOD activity and elevated MDA content, autophagy and apoptosis. With the combined performance of SP, miR-206 inhibitor and AMPK activator AICAR, the rats presented higher SOD level and lower MDA and HYP levels, suppressed autophagy and apoptosis. Meanwhile, miR-206 inhibition also contributed to elevated expression of Nampt and the extent of AMPK phosphorylation, increased Bcl-2/Bax ratio, but degraded expression of p62 and Beclin1. Collectively, inhibition of miR-206 could activate the AMPK/Nampt signalling pathway, thus protecting against myocardial I/R injury on the basis of SP.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , MicroRNAs/genética , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Nicotinamida Fosforribosiltransferase/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proteína Beclina-1/biossíntese , Genes bcl-2/fisiologia , Miócitos Cardíacos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/metabolismo , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Sevoflurano/farmacologia , Proteína X Associada a bcl-2/biossíntese
12.
Food Chem ; 293: 103-111, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151589

RESUMO

Defects with textures and flavors are a common problem, causing many economic losses in the dry-cured ham industry. To obtain a better understanding of the defects of dry-cured ham, texture, protein denaturation, protein structure, and water distribution of normal and defective hams were investigated. Compared with normal ham, more than 1.5-fold values in adhesiveness and bitterness, and less than 0.8-fold values in hardness were found in defective ham. The intense denaturation of sarcoplasmic proteins and actin, and the dramatic transformation of α-helix to ß-sheet were the key modification of proteins; a high proportion (92.39%) of immobile water contributed to the excessive softness and adhesiveness of defective hams. Furthermore, high denaturation of proteins could accelerate the degradation of proteins, which further developed the bitterness and adhesiveness of defective hams. Partial least squares regression demonstrated that the discrepancies in protein denaturation, protein structure and water distribution were related with bitterness and adhesiveness of Jinhua ham.


Assuntos
Produtos da Carne/análise , Proteínas/química , Água/química , Adesividade , Animais , Análise de Componente Principal , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Desnaturação Proteica , Suínos , Paladar
13.
Food Chem ; 297: 125012, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253295

RESUMO

To obtain better understanding of the formation mechanisms of bitterness and adhesiveness, protease activities, proteolysis index and protein degradation were investigated among raw, normal and defective hams. Normal and defective hams both showed a decrease in cathepsin B and B + L activities compared with raw ham, while higher residual activities were observed in defective ham. Approximate 1.2-fold values of proteolysis index were observed in defective ham than in normal ham, indicating that cathepsin B and B + L activities were key contributors in degrading muscle proteins of dry-cured ham. 322 proteins were identified by label-free proteomics, and 49 down-regulated proteins were found in the comparison between normal and defective hams. Creatine kinase, myosin, α-actinin and troponin-T showed the most intense response to bitterness and adhesiveness of dry-cured ham, confirmed by partial least squares regression analysis. Myosin could be a suitable biomarker to monitor bitterness and adhesiveness of dry-cured ham.


Assuntos
Produtos da Carne/análise , Proteômica/métodos , Paladar/fisiologia , Adesividade , Animais , Catepsina B/metabolismo , Catepsina L/metabolismo , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Regulação para Baixo , Análise dos Mínimos Quadrados , Proteínas/análise , Proteólise , Suínos , Espectrometria de Massas em Tandem , Troponina T/análise
14.
World J Gastroenterol ; 24(20): 2191-2202, 2018 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-29853737

RESUMO

AIM: To examine the relationship between the single nucleotide polymorphism CXCL10 rs1439490 and seronegative occult hepatitis C virus (HCV) infection (OCI). METHODS: One hundred and three cases of seronegative OCI and 155 cases of seropositive chronic HCV infection (CHC) were diagnosed at five Liver Centers in Northeastern China, from 2012 to 2016. CXCL10 rs1439490, rs1440802, and IL-28B rs12979860 were analyzed by sequencing. Serum CXCL10 was measured by ELISA. Intrahepatic CXCL10 was determined by quantitative PCR and immunohistochemical semi-quantitative scoring. Liver necroinflammation and fibrosis were scored according to the METAVIR system. RESULTS: CXCL10 rs1439490 G/G was more prevalent in OCI patients (n = 93/103; 90.3%) than in CHC patients (n = 116/155; 74.8%; P = 0.008). OCI patients had lower serum CXCL10 levels than CHC patients (192.91 ± 46.50 pg/mL vs 354.78 ± 102.91 pg/mL, P < 0.0001). Of IL-28B rs12979860 C/C patients, OCI patients with rs1439490 G/G had lower serum and liver levels of CXCL10 and lower levels of liver necroinflammation and fibrosis than non-G/G patients. OCI patients had higher alanine aminotransferase normalization rates after Peg-interferon treatment than CHC patients (P < 0.05) and serum CXCL10 decreased significantly (P < 0.0001). Liver necroinflammation and fibrosis were alleviated in 8 OCI patients after treatment. Multivariate analysis indicated that rs1439490 G/G significantly influenced the occurrence of OCI in HCV infection (OR = 0.31, 95%CI: 0.15-0.66, P = 0.002). CONCLUSION: CXCL10 rs1439490 G/G is positively associated with OCI in HCV infection and antiviral outcome.


Assuntos
Antivirais/uso terapêutico , Quimiocina CXCL10/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/genética , Interleucinas/genética , Adulto , Biópsia , Quimiocina CXCL10/sangue , China , Feminino , Hepacivirus/genética , Hepatite C Crônica/sangue , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Humanos , Interferon-alfa/uso terapêutico , Interferons , Fígado/enzimologia , Fígado/patologia , Fígado/virologia , Cirrose Hepática/sangue , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/uso terapêutico , Polimorfismo de Nucleotídeo Único , RNA Viral/isolamento & purificação , Proteínas Recombinantes/uso terapêutico , Ribavirina/uso terapêutico , Testes Sorológicos , Resultado do Tratamento
15.
J Sci Food Agric ; 98(9): 3563-3570, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29315583

RESUMO

BACKGROUND: In order to evaluate the effect of cooking temperature on the nutrition quality of dry-cured hams, 60 biceps femoris samples from 16 Jinhua hams were divided into four groups (control, 70, 100 and 120 °C) and cooked for 30 min. Carbonyl content, sulfhydryl groups, surface hydrophobicity, microstructure, protein aggregation and digestibility of myofibrillar proteins were investigated. RESULTS: Cooking promoted carbonylation and decreased sulfhydryl groups in a temperature-dependent way. Scanning electron microscopy and Nile Red revealed that protein aggregation became a main phenomenon at 120 °C; it coincided with surface hydrophobicity. The increased carbonyl content and decreased sulfhydryl groups contributed to the formation of aggregates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles showed the initial difference in proteolysis rate among four groups. The in vitro digestibility of pepsin and of trypsin and α-chymotrypsin increased from the control to 100 °C and decreased from 100 to 120 °C. CONCLUSION: The increased digestibility could be attributed to the oxidation of proteins and exposing recognition sites of digestive enzymes, while the decreased digestibility was due to the formation of aggregates. Cooking was a main factor that affected the digestibility of Jinhua ham, and cooking at 100 °C could be an ideal way to gain the highest digestibility of Jinhua ham. © 2018 Society of Chemical Industry.


Assuntos
Culinária/métodos , Carne/análise , Proteínas Musculares/metabolismo , Miofibrilas/metabolismo , Suínos , Temperatura , Animais , China , Digestão , Microscopia Eletrônica de Varredura , Proteínas Musculares/química , Agregados Proteicos , Compostos de Sulfidrila/análise
16.
Poult Sci ; 97(2): 684-694, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29121270

RESUMO

In order to study the tenderization mechanism of ATP treatments by depolymerizing actin filaments, breast muscles of Eastern Zhejiang White Geese were randomly divided into 3 groups: control, 10 and 20 mM groups. Shear force (SF), sarcomere length (SL) and myofibrillar fraction index (MFI), the content of F-actin and G-actin, the expression of actin associated proteins (cofilins and tropomodulins) were investigated during conditioning. In 20 mM group, cofilins content increased from 48 to 168 h, while tropomodulins decreased; the content of F-actin decreased from 24 to 168 h, while the increased G-actin was observed upto 48 h. In the control, the degraded tropomodulins were observed at 168 h, and the increased cofilins and G-actin were detected at the same time; the increase of MFI and decrease of F-actin content were shown at 96 and 168 h. Compared to control group, 20 mM group accelerated the transformation of F-actin into G-actin; it showed higher SL and MFI, and lower SF at 48, 96 and 168 h, respectively. We concluded that depolymerization of actin filaments, which was regulated by cofilins and tropomodulins, contributed to myofibrillar fraction and low SF during conditioning.


Assuntos
Citoesqueleto de Actina/química , Trifosfato de Adenosina/química , Gansos , Carne/análise , Músculo Esquelético/química , Sarcômeros/fisiologia , Fatores de Despolimerização de Actina/química , Actinas/química , Animais , Masculino , Resistência ao Cisalhamento , Tropomodulina/química
17.
Food Chem ; 240: 346-353, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28946282

RESUMO

To investigate the influence of oxidative modifications of G-actin on its binding ability with aroma compounds, the influence of H2O2 treatments on G-actin structure and the absorption for alcohols and aldehydes was investigated. Raman spectroscopy and scanning electron microscopy were used to evaluate structural changes of G-actin; GC-MS was used to analyze the binding with alcohols and aldehydes. Results showed that 0-5mM H2O2 enhanced the absorption of G-actin toward alcohols involved in the formation of hydrogen bonds by increasing α-helix and carbonyl values. 0-1mM H2O2 caused the release of aldehydes with decreased sulfhydryl sites. 1-20mM H2O2 increased the retention of aldehydes, due to the increased hydrophobic sites by G-actin rebuilding and aggregating. The aggregated G-actin favoured the hydrophobic interactions with aroma compounds, forming the protein-aroma compound complex, thus enhancing the resultant binding ability, as evidenced by scanning electron microscopy and GC/MS analysis.


Assuntos
Actinas/química , Carpas , Animais , Peróxido de Hidrogênio , Músculo Esquelético , Oxirredução
18.
Food Sci Biotechnol ; 26(3): 679-687, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30263592

RESUMO

Twelve pieces of longissimus dorsi were processed into Chinese traditional dry-cured loins. The changes in the proteolylic enzymes activities, myofibrillar proteins degradation, and free amino acids content were investigated during processing. Compared with fresh piece (0 day), the cathepsin B + L and calpains activities decreased after dry-curing and maintained potential activities values of 23.25 and 15.04% in the final products, respectively. The myosin heavy chain (MHC) and C protein were intensely degraded at the dry-ripened stage; the 50 kDa desmin increased at day 2 and then disappeared at day 11. The total free amino acids content increased from 333.18 mg/100 g in the raw to 1096.54 mg/100 g at the end of the dry-ripening. This work provided a mechanism for the accumulation of free amino acids and predicted the proteolysis extent of myofibrillar proteins by monitoring the changes of three marker proteins (MHC, C protein and 50 kDa desmin) during Chinese traditional dry-cured loins processing.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(10): 2683-7, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24409717

RESUMO

In the present paper, two SERS-active substrates (silver mirror and HNO3 etched Ag foil) were prepared for thiuram detecting and studying. SERS can provide the molecular vibrational model and structure information of thiuram at low concentration, thus providing very valuable information regarding the structure of the adsorbed molecules. This technique also allows for the in situ study of this molecule when adsorbed on a silver surface and the identification of the chemical state when they are adsorbed on the surface of silver substrate. The SERS study of thiuram was carried out at several adsorbtion concentrations, revealing that two different coordination complexes having different geometries (monodentate and bidentate) are possible adsorbed on the silver surface. These results have a significant importance regarding the understanding of the potential environmental impact of these molecules.

20.
Zhonghua Gan Zang Bing Za Zhi ; 19(9): 670-3, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22152381

RESUMO

OBJECTIVE: To evaluate antiviral effects of Peg-IFNa-2a in patients with chronic hepatitis B. METHODS: 92 chronic hepatitis B patients were enrolled to receive the treatment with Peg-IFNa-2a 180 µg subcutaneous injection once weekly. The patients who did not get early response were divided into 3 groups: group 1, extend the treatment to 72 weeks; group 2, combined with nucleus(s)ide analogue (entecavir or adefovir) treatment; group 3, continue the treatment until 48 weeks. HBV DNA and quantitative HBsAg were assessed at baseline, week 12, 24, 36 and after 24 weeks follow-up. RESULTS: Patients in group 1 had significantly higher SVR rate (78.3%) than patients in group 3 (38.1%, X2=7.33, P<0.05). The mean reduction of HBsAg in group 1 at 24 weeks of post-treatment follow up was higher than that in group 3 (t=2.11, P<0.05). In group 2 the mean reductions of HBV DNA at 24 weeks of post-treatment follow up were (3.9+/-1.1) log10 copy/ml and (3.7+/-1.3) log10 copy/ml respectively with combination of entecavir or adefovir, both of which were significantly higher than that in group 3(t=8.45 and 6.31, P<0.05); the SVR rates in the entecavir group and the adefovir group (83.3% and 85.7%, respectively) were significantly higher than that in group 3 (X2=8.20 and 7.78, P<0.05); the mean reductions of HBsAg in the entecavir group and the adefovir group [(0.8+/-0.5) log10 IU/ml and (0.9+/-0.3) log10 IU/ml, respectively ] were significantly greater than group 3[(0.4+/-0.3) log10 IU/ml, t=3.05 and 4.58, P<0.05]. The level of HBV DNA and C genotype were the main predictors of response. CONCLUSION: Individualizing therapy by prolonging the duration of Peg-IFNa-2a treatment to 72 weeks or adding nucleoside analogues such as entecavir and adefovir in patients without early response may substantially increase the SVR rate and lead to the decrease of HBsAg.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Adenina/análogos & derivados , Adenina/uso terapêutico , Adulto , Feminino , Guanina/análogos & derivados , Guanina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Organofosfonatos/uso terapêutico , Resultado do Tratamento
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