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1.
Artículo en Inglés | MEDLINE | ID: mdl-38669622

RESUMEN

Recovery and separation of anthropogenic emissions of electronic specialty gases (F-gases, such as CF4 and SF6) from the semiconductor sector are of critical importance. In this work, the hierarchical porous UiO-66-Br2@PS/DVB-packed column was constructed by a high internal phase emulsions strategy. UiO-66-Br2@PS/DVB exhibits a superior selectivity of CF4/N2 (2.67) and SF6/N2 (3.34) predicted by the IAST due to the diffusion limitation in the micropore and the gas-framework affinity. Especially, UiO-66-Br2@PS/DVB showed significant CF4 and SF6 retention and enabled the successful separation of CF4/N2 and SF6/N2 with a resolution of 2.37 and 8.89, respectively, when used as a packed column in gas chromatography. Compared with the Porapak Q column, the HETP of the UiO-66-Br2@PS/DVB-packed column decreased and showed good reproducibility. This research not only offers a convenient method for fabricating a hierarchical porous MOF-packed column but also showcases the prospective utilization of MOFs for the separation of the F-gas/N2 mixture.

2.
Sensors (Basel) ; 23(7)2023 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-37050462

RESUMEN

The abnormal wear of a rolling element bearing caused by early failures, such as pitting and spalling, will deteriorate the running state and reduce the life. This paper demonstrates the importance of oil debris monitoring and its effective feature extraction for bearing health assessment. In this paper, a rolling bearing-rotor test rig with forced lubrication is set up and the nonferrous contaminants with higher hardness were introduced artificially to accelerate the occurrence of pitting and spalling. The early failure and abnormal wear of rolling bearings cannot be effectively detected only through the vibration signal; the temperature and oil debris monitoring data are also collected synchronously. Two features regarding the ferrous particle size distribution are extracted and fused with vibration based-features to form a feature set. The sensitive features are extracted from the features set using the Neighborhood Component Analysis method to avoid feature redundancy. Finally, the importance of the oil debris based-features for the diagnosis of abnormal bearing wear is analyzed with different machine learning algorithms. Taking SVM classifier as an example, the experiment results show that the introduction of oil debris based-features increases the diagnostic accuracy by 15.7%.

3.
Chempluschem ; 87(11): e202200324, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36420867

RESUMEN

The generation of cyclic carbonates by the cycloaddition of CO2 with epoxides is attractive in the industry, by which CO2 is efficiently used as C1 source. Herein, a series of catalysts were developed to efficient mediate the cycloaddition of CO2 with epoxides to generate carbonates. The catalysts were easily synthesized via the amine-formaldehyde condensation of ethidium bromide with a variety of linkers. The newly prepared heterogeneous catalysts have high thermal stability and degradation temperatures. The surface of the catalysts is smooth and spherical in shape. The effect of temperature, pressure, reaction time and catalyst dosage on the cycloaddition of CO2 with epoxide were investigated. The results show that the catalyst with 1,3,5-tris(4-formylphenyl)benzene as the linker can achieve 97.4 % conversion efficiency at the conditions of 100 °C, reaction time of 12 h, and the reaction pressure of 1.2 MPa in a solvent-free environment. Notably, the polymers serve as homogeneous catalysts during the reaction (reaction temperature above Tg ) and can be separated and recovered easily as homogeneous catalysts at room temperature. In addition, the catalyst is not only suitable for a wide range of epoxide substrates, but also can be recycled many times. Furthermore, DFT calculations show that the coordination between the electrophilic center of the catalyst and the epoxide reduces the energy barrier, and the reaction mechanism is proposed based on the reaction kinetic studies and DFT calculations.


Asunto(s)
Dióxido de Carbono , Compuestos Epoxi , Reacción de Cicloadición , Solventes , Polímeros , Cinética , Carbonatos
4.
Angew Chem Int Ed Engl ; 61(43): e202208898, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-35983616

RESUMEN

Two imine-based covalent organic framework photocatalysts with different building units, TPB-DMTA-COF and TAT-DMTA-COF, for photo-induced energy transfer reversible complexation-mediated radical polymerization (PET-RCMP) were developed and investigated, producing ideal polymers with accurate molecular weight and moderate dispersity under visible light irradiation. The chain extension and spatiotemporal control experiments revealed the high chain-end fidelity of polymers and the compatibility of RCMP processes in both bulk and aqueous system. Moreover, density functional theory (DFT) calculations verified that heteroatom-doped TAT-DMTA-COF exhibits higher activities for weakening C-I bond energy barrier, which promotes PET-RCMP polymerization performance. This work demonstrates that rational adjustment of building block for constructing COF heterogeneous photocatalyst can enhance the catalytic performance of PET-RCMP, providing a design methodology for the development of polymeric organic photoelectric semiconductor catalysts to mediate RCMP.

5.
Sensors (Basel) ; 22(5)2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35271084

RESUMEN

During its operation, a rotor system can be exposed to multiple faults, such as rub-impact, misalignment, cracks and unbalancing. When a crack fault occurs on the rotor shaft, the vibration response signals contain some nonlinear components that are considerably tougher to be extracted through some linear diagnosis methods. By combining the Nonlinear Output Frequency Response Functions weighted contribution rate (WNOFRFs) and Kullback-Leibler (KL) divergence, a novel fault diagnosis method of improved WNOFRFs is proposed. In this method, an index, improved optimal WNOFRFs (IOW), is defined to represent the nonlinearity of the faulty rotor system. This method has been tested through the finite element model of a cracked rotor system and then verified experimentally at the shaft crack detection test bench. The results from the simulation and experiment verified that the proposed method is applicable and effective for cracked rotor systems. The IOW indicator shows high sensitivity to crack faults and can comprehensively represent the nonlinear properties of the system. It can also quantitatively detect the crack fault, and the relationship between the values of IOW and the relative depth of the crack is approximately positively proportional. The proposed method can precisely and quantitatively diagnose crack faults in a rotor system.

6.
Macromol Rapid Commun ; 42(20): e2100384, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34418210

RESUMEN

Covalent organic frameworks (COFs) are a class of promising photocatalysts for conversing light energy into chemical energy. Based on the tunable building blocks, COFs can be well-designed as photocatalyst for mediating reversible addition-fragmentation chain-transfer (RAFT) polymerization. Herein, 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) and 2,2″-bipyridine-5,5″-diamine (Bpy) are chosen to construct imine-based TFPPy-Bpy-COFs for catalyzing RAFT polymerization of methacrylates under white light irradiation. The well-defined polymers with precise molecular weight and narrow molecular weight distribution are obtained. The switch on/off light experiments suggest excellent temporal control toward RAFT polymerization system and the chain-extension reaction indicates high chain-end fidelity of macro-initiators. Mechanism study clarifies that the electron transfer between excited state of TFPPy-Bpy-COFs and RAFT agent can form living radicals to mediate polymerization. This methodology provides a novel platform for reversible-deactivation radical polymerization using COFs as heterogeneous catalysts.


Asunto(s)
Estructuras Metalorgánicas , Catálisis , Luz , Polimerizacion , Tomografía de Emisión de Positrones
7.
J Colloid Interface Sci ; 563: 414-425, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31896487

RESUMEN

Biomass carbon materials which have the merits of green, low cost and renewability, can be obtained from sodium alginate (SA) beads crosslinked by polyvalent metal ions. SA beads are possible to be obtained using diammoniums as the crosslinking agents. In this work, N-O codoped porous carbon (NO-PC) was prepared from SA beads crosslinked by diammoniums through the electrostatic interaction between ammonium cations and carboxylate groups of SA chains. The using of diammoniums as the crosslinkers achieved N doping into NO-PC. Scanning and transmission electron microscope observations revealed that NO-PC possessed hierarchically porous characteristic. X-ray photoelectron spectroscopy identified the successful N-O codoping. Both the species and concentration of diammoniums strongly affected the porous structure, surface area and electrochemical performance of NO-PC. N2 adsorption-desorption results of NO-PC indicated that the highest surface area was up to 3794 m2/g. The NO-PC based supercapacitors showed high specific capacities up to 269.0 F/g at 1 A/g and excellent cycling stability (92.09% after 5000 cycles at 5 A/g). The energy density of the symmetric supercapacitor was up to 18.9 Wh/kg at a power density of 1380 W/kg with a voltage window of -1.4-0 V.

8.
Langmuir ; 34(40): 12100-12108, 2018 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-30212212

RESUMEN

The superior capability of gemini surfactant (GS) in the preparation of hierarchically porous carbons via high-internal-phase emulsion (HIPE) template followed by pyrolysis was confirmed in this work. Polymerized HIPEs (polyHIPEs) of phenol-formaldehyde resin were prepared by cross-linking the continuous phase of HIPEs stabilized by GS. Nonionic surfactant and cationic surfactant were also selected to stabilize HIPE for comparison. From scanning electron microscope observations, polyHIPEs with open-cell pore architectures were obtained with GS as emulsifier (polyHIPEs-GS) and the derived carbon foams (carboHIPEs-GS) well retained the original pore architectures, whereas polyHIPEs obtained using contrastive surfactants showed closed-cell porous structures and notable differences were observed for the derived carboHIPEs. Nitrogen adsorption/desorption measurements indicated that polyHIPEs-GS and carboHIPEs-GS both exhibited hierarchically porous architectures with much higher surface areas (SA) than those of the corresponding contrast samples. Mercury intrusion porosimetry results indicated that carboHIPEs-GS possessed higher SA and higher porosity than that of the contrast samples. The open-cell pore architecture and high SA are favorable to many applications, like energy storage. carboHIPE-GS expectably showed a higher capacitance than that of contrast samples when used as the electrode material of supercapacitor.

9.
Carbohydr Polym ; 173: 701-706, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-28732916

RESUMEN

Development of bio-based hydrogels with good mechanical properties is of great importance for their excellent biocompatibility and biodegradability. In this paper, chitosan (CS) based double network (DN) hydrogel was prepared by dissolving CS in AlCl3·6H2O aqueous solution instead of acetic acid solution. After dissolving acrylic amide (AM), acrylic acid (AA), N, N'-methylenebisacrylamide and 2-hydroxy-4'-(2-hydoxyethoxy)-2-methylpropiophenone were added into the CS/Al3+ solution and the CS/PAMAA-Al3+ DN hydrogel was prepared by UV polymerization. The hybrid physical and chemical crosslinked network hydrogels were prepared. The tensile and compression properties of CS/PAMAA-Al3+ DN hydrogel were studied. The results showed that the CS/PAMAA-Al3+ DN hydrogels have high toughness, stretch-ability, and excellent shape recovery properties. The CS/PAMAA-Al3+ DN hydrogel could show the tensile strength of 0.54MPa and elongation at break of 2203.7%. These properties arise from the dynamic ionic interaction between Al3+ and CS/PAMAA macromolecular chains.

10.
Int J Biol Macromol ; 82: 223-30, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26608006

RESUMEN

The effects of different inorganic salts LiCl, MgCl2·6H2O, CaCl2, and AlCl3·6H2O on the crystalline, thermal, water vapor barrier, and tensile properties of starch/PVA films were studied. The high plasticizing efficiency of all these four inorganic salts for starch/PVA film was confirmed by the obtained results. These four salts all had a good compatibility with starch/PVA within the content of 15 wt% and starch/PVA became completely miscible with the addition of 15 wt% inorganic salts. All these four salts had a strong destroying effect on the crystals of starch and PVA. Among these four salts, AlCl3·6H2O had the largest negative effect on the thermal stability of starch/PVA and LiCl had the largest improving effect on the water sorption rate of starch/PVA film. On the whole MgCl2·6H2O and CaCl2 were the more suitable plasticizer for starch/PVA film among these four inorganic salts. With the addition of 15 wt% MgCl2·6H2O and CaCl2, the elongation at break of starch/PVA film could reach to 418.83% and 434.80%, respectively.


Asunto(s)
Plastificantes/química , Alcohol Polivinílico/química , Sales (Química)/química , Almidón/química , Rastreo Diferencial de Calorimetría , Interacciones Hidrofóbicas e Hidrofílicas , Fenómenos Mecánicos , Sales (Química)/farmacología , Termogravimetría , Difracción de Rayos X
11.
Carbohydr Polym ; 135: 191-8, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26453868

RESUMEN

The AlCl3·6H2O aqueous solution was used to dissolve chitosan (CS) and the CS/poly(vinyl alcohol) (PVA) blend films were prepared at the absence of acetic acid. AlCl3·6H2O was retained in CS/PVA film and glycerol was added to form the complex plasticizer with AlCl3·6H2O. The effect of glycerol on the water sorption, crystalline, thermal and mechanical properties of AlCl3·6H2O doped CS/PVA film was studied by atomic force microscopy, X-ray diffraction, thermal gravity analysis and tensile testing, respectively. The experimental results showed that glycerol had a significant positive effect on the properties of AlCl3·6H2O doped CS/PVA films. With the synergism effect of AlCl3·6H2O and glycerol, the prepared CS/PVA films showed excellent mechanical properties. With the addition of 30wt% glycerol, the AlCl3·6H2O doped CS/PVA films behave the tensile strength of 39MPa and elongation at break of 120%, respectively.

12.
Mol Oncol ; 9(7): 1312-23, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25841765

RESUMEN

Targeted therapy is currently under intensive investigation due to the resistance of liver cancer to cytotoxic chemotherapies. Dissecting the molecular events that drive the progression of liver cancer and defining specific targets are urgently needed to develop efficient tailored therapies. Cell membrane gp96 (mgp96) has been implicated in tumor growth and malignancy. Here, we explored the functional and clinical relevance of mgp96 in liver cancer. We found that elevated mgp96 abundance was associated with tumor metastasis and recurrence in patients with primary liver tumors. Decreased KDELR1 levels in hepatoma cells contribute to cell membrane translocation of the normally ER-resident gp96. Urokinase-type plasminogen activator receptor (uPAR) was identified as a mgp96 client protein, and mgp96 stabilized uPAR protein. Our clinical results proved that elevated mgp96 abundance is positively correlated with uPAR expression levels in liver tumors. We further provided evidence that targeting mgp96 with siRNA or a specific mAb that blocked the mgp96-uPAR interaction led to inhibited cell growth, survival, and invasion in vitro, as well as the suppression of liver tumor growth and metastasis in vivo. mgp96 promotes liver cancer progression through increasing the protein stability and signaling of uPAR, and may be a new promising target for suppressing uPAR-mediated tumor growth and metastasis in liver cancer.


Asunto(s)
Neoplasias Hepáticas/patología , Glicoproteínas de Membrana/fisiología , Invasividad Neoplásica/fisiopatología , Metástasis de la Neoplasia/fisiopatología , Receptores del Activador de Plasminógeno Tipo Uroquinasa/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Ratones Endogámicos BALB C , Persona de Mediana Edad
13.
BMC Infect Dis ; 14: 608, 2014 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-25465805

RESUMEN

BACKGROUND: Intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is the original template for HBV replication. The persistence of cccDNA is responsible for the recurrence of HBV infection. The detection of cccDNA can help the development of new antiviral drugs against HBV replication links, and reduce the resistance and recurrence as well as to discover extrahepatic HBV infection. In situ polymerase chain reaction (IS-PCR) can be used to determine the distribution and localization of cccDNA in liver tissues, but it is hampered by its low sensitivity and specificity. We developed a novel method to detect HBV cccDNA using rolling circle amplification (RCA) combined with IS-PCR. METHODS: Biopsy liver tissues were obtained from 26 patients with HBV infection, including 10 chronic hepatitis B (CHB), 6 liver cirrhosis (LC) and 10 hepatocellular carcinoma (HCC) patients. Four pairs of primers were designed to mediating RCA for the first round amplification of HBV cccDNA specifically. The liver tissue sections from patients were treated by plasmid-safe ATP-dependent DNase (PSAD) prior to RCA. After RCA, HBV cccDNA was further amplified by a pair of selective primers labeled digoxigenin that target the gap region between the two direct repeat regions (DR1 and DR2) of the virus via IS-PCR. RESULTS: HBVcccDNA was expressed and located in hepatocyte nucleus in 19 patients (73.07%). Compared with the IS-PCR, the introduction of RCA increase the limit of detection. RCA combined with IS-PCR yielded strong positive signals in HCC liver tissue in spite of low copy number cccDNA (2 copies of target sequence per cell), meanwhile, no positive signal was detected via negative control. CONCLUSIONS: RCA combined with IS-PCR is an effective and practicable method which could detect the presence of low copy number of cccDNA sensitively and specifically, and reflect the relationship between cccDNA expression level and liver tissue pathological characteristics.


Asunto(s)
Virus de la Hepatitis B/genética , Hepatitis B Crónica/virología , Cartilla de ADN/genética , ADN Circular/análisis , ADN Viral/análisis , Femenino , Hepatocitos/virología , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad
14.
Hepatology ; 58(1): 139-49, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22961630

RESUMEN

UNLABELLED: The role of CD4(+) cytotoxic T cells (CTLs) in hepatocellular carcinoma (HCC) remains obscure. This study characterized CD4(+) CTLs in HCC patients and further elucidated the associations between CD4(+) CTLs and HCC disease progression. In all, 547 HCC patients, 44 chronic hepatitis B (CHB) patients, 86 liver cirrhosis (LC) patients, and 88 healthy individuals were enrolled in the study. CD4(+) CTLs were defined by flow cytometry, immunohistochemistry, and lytic granule exocytosis assays. A multivariate analysis of prognostic factors for overall survival was performed using the Cox proportional hazards model. Circulating and liver-infiltrating CD4(+) CTLs were found to be significantly increased in HCC patients during early stage disease, but decreased in progressive stages of HCC. This loss of CD4(+) CTLs was significantly correlated with high mortality rates and reduced survival time of HCC patients. In addition, the proliferation, degranulation, and production of granzyme A, granzyme B, and perforin of CD4(+) CTLs were inhibited by the increased forkhead/winged helix transcription factor (FoxP3(+) ) regulatory T cells in these HCC patients. Further analysis showed that both circulating and tumor-infiltrating CD4(+) CTLs were independent predictors of disease-free survival and overall survival after the resection of the HCC. CONCLUSION: The progressive deficit in CD4(+) CTLs induced by increased FoxP3(+) regulatory T cells was correlated with poor survival and high recurrence rates in HCC patients. These data suggest that CD4(+) CTLs may represent both a potential prognostic marker and a therapeutic target for the treatment of HCC.


Asunto(s)
Linfocitos T CD4-Positivos/patología , Carcinoma Hepatocelular/patología , Factores de Transcripción Forkhead/metabolismo , Hepatitis B Crónica/patología , Neoplasias Hepáticas/patología , Linfocitos T Citotóxicos/patología , Adulto , Carcinoma Hepatocelular/mortalidad , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Granzimas/biosíntesis , Hepatitis B Crónica/complicaciones , Humanos , Hígado/patología , Neoplasias Hepáticas/mortalidad , Linfocitos Infiltrantes de Tumor/fisiología , Masculino , Persona de Mediana Edad , Perforina , Proteínas Citotóxicas Formadoras de Poros/biosíntesis , Pronóstico , Recurrencia , Linfocitos T Reguladores/metabolismo
15.
Artículo en Chino | MEDLINE | ID: mdl-23189846

RESUMEN

OBJECTIVE: To explore whether the cellular apoptosis susceptibility (CAS) protein could serve as a pathologic marker for HCC diagnosis and the roles of CAS expression in HBV infection associated HCC. METHODS: The expression of CAS protein in HCC and its paracarcinoma tissues, non-tumor liver cirrhosis and hepatitis tissues were detected by immunohistochemistry. Meanwhile, HBsAg, HBcAg and HBV DNA in HCC tissues with HBV infection were examined by immunohistochemistry and in situ hybridization respectively. RESULTS: The expression of CAS protein was significantly higher in HCC than in its paracarcinomas tissues (P < 0.01), and higher in paracarcinomas tissues than in non-tumor liver cirrhosis and hepatitis tissues (P < 0.01). Poorly differentiated tumors immunochemically stained stronger than moderately or well differentiated (P < 0.01). CAS protein expression was significantly higher in HBV-infected HCC tissues than that of in non-HBV infection (P < 0.01). Meanwhile, in HBV-infected HCC tissues, the staining intensity score of CAS protein in HBV DNA positive HCC tissues was significantly higher than HBV DNA negative tissues (P < 0.05). CONCLUSIONS: Higher expression of CAS protein is found in HCC tissues,and the intensity of CAS protein expression is related closely to tumor differentiation. We suggested that CAS protein might serve as a marker for HCC diagnosis and differentiation estimation, and deduced that CAS might play an important role in the initiation of HBV infection associated HCC through upregulating expression of CAS.


Asunto(s)
Carcinoma Hepatocelular/genética , Proteína de Susceptibilidad a Apoptosis Celular/genética , Virus de la Hepatitis B/fisiología , Neoplasias Hepáticas/genética , Adulto , Anciano , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/virología , Proteína de Susceptibilidad a Apoptosis Celular/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Antígenos del Núcleo de la Hepatitis B/genética , Antígenos del Núcleo de la Hepatitis B/metabolismo , Antígenos de Superficie de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B/metabolismo , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/aislamiento & purificación , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad
16.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 27(7): 801-2, 2011 Jul.
Artículo en Chino | MEDLINE | ID: mdl-22031962

RESUMEN

AIM: To investigate the value of Brn-3a immunocytochemistry of liquid-based ThinPrep cytology test(TCT) in early diagnosis of cervical process. METHODS: Patients(192) were investigated in the present study. TCT was used in all the patients. Immunohistochemistry was per-formed to examine the expressions of Brn-3a. The pathological results were used as the gold standard to evaluate the results of TCT method and Brn-3a in combination with LCT. RESULTS: Compared with the pathological results, the accuracies of TCT method were 76.9% (30/39) , 80.5% (33/41)and 96.8% (30/31) in LSIL, HSIL, SCC respectively. The accuracies of Brn-3a in combination with TCT were 76. 9%(30/39), 78.6%(33/42) and 97.1% (30/31) in LSIL, HSIL and SCC respectively. The difference was significant in the diagnosis of LSIL and HSIL (P <0.05). CONCLUSION: The detection of Brn-3a is of important clinic value in early diagnosis of cervical process.


Asunto(s)
Detección Precoz del Cáncer/métodos , Inmunohistoquímica/métodos , Factor de Transcripción Brn-3A/metabolismo , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/metabolismo , Adulto , Femenino , Humanos , Persona de Mediana Edad , Neoplasias del Cuello Uterino/patología , Adulto Joven
17.
Clin Chim Acta ; 412(21-22): 1905-11, 2011 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-21741960

RESUMEN

BACKGROUND: The study aimed to develop an effective method to quantitate HBV covalently closed circular DNA (cccDNA) using small section of formalin fixed paraffin-embedded (FFPE) liver biopsy. METHODS: Plasmid-safe ATP-dependent DNase (PSAD)-treated samples were subjected to rolling circle amplification (RCA) prior to real-time PCR mediated by cccDNA-selective primers. Human beta-actin gene was used as a reference control. RESULTS: Compared to the classical method, i.e., PSAD digestion+real-time PCR, introduction of RCA increased the lower limit of detection for about 2 logs with good inter- and intra-assay reproducibility. HBV cccDNA was detected in 91.5% (119/130) of the FFPE samples. The cccDNA levels (copy/cell) between FFPE liver tissues and fresh frozen counterpart tissues were comparable. The median of cccDNA level in HBeAg-positive patients was higher than that in HBeAg-negative ones (52.60 vs. 31.25copies/cell, P<0.01). Intrahepatic cccDNA level was positively correlated with intrahepatic HBV total DNA level, but not obviously correlated with serum HBV DNA or alanine aminotransferase levels. CONCLUSIONS: The method could sensitively and specifically quantitate intrahepatic HBV cccDNA in micro FFPE liver biopsy tissue for evaluation of HBV replication status in the liver.


Asunto(s)
ADN Circular/genética , ADN Viral/genética , Virus de la Hepatitis B/genética , Hígado/patología , Adhesión en Parafina/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Femenino , Humanos , Hígado/virología , Masculino , Sensibilidad y Especificidad
18.
Scand J Gastroenterol ; 45(11): 1360-71, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20560816

RESUMEN

OBJECTIVE: There is no animal model that displays the features of non-alcoholic steatohepatitis (NASH) characterized by insulin resistance (IR) and fibrosing steatohepatitis. This study aimed to develop a novel IR-associated rat model of NASH. MATERIAL AND METHODS: Male Sprague-Dawley rats were fed with the high-fat diet (HFD) supplemented with 0.25% propylthiouracil for 2, 4, 6, 8 and 12 weeks. The IR-associated metabolic parameters, histological assessment and the expression of key insulin signaling molecules were determined. The circulating and tissue pro-inflammatory factors and adipocytokines were examined. RESULTS: In the HFD-fed rats, the systemic and multiple-organ IR was developed after 4 weeks, whereas the histological changes characterized by steatohepatitis, inflammatory response in the visceral adipose tissue and proliferative pancreatic islet ß-cells appeared after 6 weeks, concomitant with altered expression of key insulin signaling molecules. In addition, the elevated levels of serum tumor necrosis factor α (TNF-α), soluble TNF receptor2, interleukin (IL)-6, CC-chemokine ligand (CCL)2 and resistin were parallel with the severity of hepatic inflammation, while the levels of serum adiponectin, leptin and TNF-α, but not resistin, were correlated with IR. CONCLUSIONS: We have developed a systemic IR-associated NASH model of rats, with impaired insulin signaling, systemic inflammation and appropriate pathology characterized by human NASH, and provided a realistic experimental model for elucidating the association between IR and the pathogenesis of NASH.


Asunto(s)
Adiponectina/sangre , Quimiocinas/metabolismo , Hígado Graso/metabolismo , Hepatitis/complicaciones , Resistencia a la Insulina , Leptina/sangre , Cirrosis Hepática/complicaciones , Adiponectina/genética , Animales , Quimiocinas/genética , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Hígado Graso/complicaciones , Hígado Graso/patología , Regulación de la Expresión Génica , Hepatitis/metabolismo , Hepatitis/patología , Leptina/genética , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Masculino , Reacción en Cadena de la Polimerasa , ARN/genética , Ratas , Ratas Sprague-Dawley , Resistina/metabolismo , Índice de Severidad de la Enfermedad
19.
Zhonghua Gan Zang Bing Za Zhi ; 15(3): 212-5, 2007 Mar.
Artículo en Chino | MEDLINE | ID: mdl-17407714

RESUMEN

OBJECTIVE: To study the clinical and pathological features of drug-induced liver injury (DILI). METHODS: Liver specimens were obtained through needle biopsies from 100 patients with DILI. The histological preparations of the specimens were stained with haematoxylin eosin, several histochemistry methods, and immunohistochemistry stains. The pathological changes of the livers were analyzed together with the patients's clinical data. The patients were divided into two groups, an acute DILI group (n=39) and a chronic DILI group (n=61), based on their clinical courses and histological changes in their livers. In the chronic DILI group, the clinical courses were longer than 6 months and/or fibrosis or cirrhosis occurred in their liver tissues. RESULTS: Among our cases the leading cause of DILI was Chinese herb medicine, accounting for 21% of the 100 cases; steroids induced cases were 11% of the total. 78% of the patients presented elevated serum transaminases and/or jaundice. The degree of transaminases elevation and the frequency of jaundice happening in the acute group were significantly higher than those in the chronic group (P less than 0.05). The histopathological liver changes in these DILI cases included: (1) necrosis commonly occurred in acinar zone 3, (2) abundant neutrophil and/or eosinophil infiltrations, (3) hepatocytic and/or canalicular cholestasis with little or no inflammation, (4) microvesicular steatosis mixed with macrovesicular steatosis, and (5) presentation of epitheloid cell granuloma. There were no significant differences in liver histopathology between the acute and the chronic DILI groups, except that the fibrosis and the ductular proliferation were different. CONCLUSION: DILI has become a notable liver disease in mainland China, and the use of Chinese herbal medicine must be improved, standardized and regulated more closely.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hígado/patología , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
20.
Front Med China ; 1(4): 413-7, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24573937

RESUMEN

To summarize the pathological features of nonalcoholic liver disease (NAFLD) in China based on a histological scoring system for NAFLD designed by the Pathology Committee of NASH Clinical Research Network (NASH-CRN), the specimens of liver needle biopsies from 130 patients with NAFLD were histopathologically analyzed by haematoxylin eosin, reticular fiber and Masson trichrome stain. Immunohistochemistry staining was used to exclude non-NAFLD cases combined with clinical data. Hepatic steatosis, lobular inflammation, hepatocytic ballooning and fibrosis were presented widespread in NAFLD liver tissues. Furthermore, macrovesicular steatosis predominantly located in acinar zone 3 was the main histologic feature of NAFLD and lobular inflammation was usually presented mildly. Hepatocyte ballooning was observed in 94.6% of all 130 cases. Mild perisinusoidal fibrosis and periportal fibrosis were often observed in stage 1 cases. According to the statistic analysis, hepatic steatosis was positively correlated with lobular inflammation, hepatocytic ballooning and fibrosis (r = 0.587, 0.488, 0.374, respectively, all P value < 0.01). The number of microgranulomas, lipogranulomas and apoptotic bodies increased following severity of steatosis, lobular inflammation and fibrosis. Meanwhile, the number of megamitochondria and glycogen nuclei was paralleveled to the degree of hepatocytic ballooning (P value all < 0.01). We suggest that the role of portal inflammation should be emphasized besides hepatic steatosis, lobular inflammation, hepatocyte ballooning and fibrosis in diagnosis and evaluation of NAFLD. It needs to be further verified whether microgranulomas, lipogranulomas and apoptosis bodies could be used as histopathological markers of development of NAFLD. The number of megamitochondria is more frequently be found in NAFLD, while in alcoholic liver diseases was Mallory bodies.

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