Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
J Colloid Interface Sci ; 664: 469-477, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38484515

RESUMO

Transition metal oxides have been acknowledged for their exceptional water splitting capabilities in alkaline electrolytes, however, their catalytic activity is limited by low conductivity. The introduction of sulfur (S) into nickel molybdate (NiMoO4) at room temperature leads to the formation of sulfur-doped NiMoO4 (S-NiMoO4), thereby significantly enhancing the conductivity and facilitating electron transfer in NiMoO4. Furthermore, the introduction of S effectively modulates the electron density state of NiMoO4 and facilitates the formation of highly active catalytic sites characterized by a significantly reduced hydrogen absorption Gibbs free energy (ΔGH*) value of -0.09 eV. The electrocatalyst S-NiMoO4 exhibits remarkable catalytic performance in promoting the hydrogen evolution reaction (HER), displaying a significantly reduced overpotential of 84 mV at a current density of 10 mA cm-2 and maintaining excellent durability at 68 mA cm-2 for 10 h (h). Furthermore, by utilizing the anodic sulfide oxidation reaction (SOR) instead of the sluggish oxygen evolution reaction (OER), the assembled electrolyzer employing S-NiMoO4 as both the cathode and anode need merely 0.8 V to achieve 105 mA cm-2, while simultaneously producing hydrogen gas (H2) and S monomer. This work paves the way for improving electron transfer and activating active sites of metal oxides, thereby enhancing their HER activity.

2.
Proc Natl Acad Sci U S A ; 121(10): e2312150121, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38412127

RESUMO

African swine fever, one of the major viral diseases of swine, poses an imminent threat to the global pig industry. The high-efficient replication of the causative agent African swine fever virus (ASFV) in various organs in pigs greatly contributes to the disease. However, how ASFV manipulates the cell population to drive high-efficient replication of the virus in vivo remains unclear. Here, we found that the spleen reveals the most severe pathological manifestation with the highest viral loads among various organs in pigs during ASFV infection. By using single-cell-RNA-sequencing technology and multiple methods, we determined that macrophages and monocytes are the major cell types infected by ASFV in the spleen, showing high viral-load heterogeneity. A rare subpopulation of immature monocytes represents the major population infected at late infection stage. ASFV causes massive death of macrophages, but shifts its infection into these monocytes which significantly arise after the infection. The apoptosis, interferon response, and antigen-presentation capacity are inhibited in these monocytes which benefits prolonged infection of ASFV in vivo. Until now, the role of immature monocytes as an important target by ASFV has been overlooked due to that they do not express classical monocyte marker CD14. The present study indicates that the shift of viral infection from macrophages to the immature monocytes is critical for maintaining prolonged ASFV infection in vivo. This study sheds light on ASFV tropism, replication, and infection dynamics, and elicited immune response, which may instruct future research on antiviral strategies.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Suínos , Animais , Vírus da Febre Suína Africana/fisiologia , Baço/patologia , Replicação Viral , Macrófagos/patologia
3.
Sci Prog ; 106(4): 368504231210361, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37933475

RESUMO

To solve the time-delay problem and actuator saturation problem of nonlinear plants in industrial processes, an improved compact-form antisaturation model-free adaptive control (ICF-AS-MFAC) method is proposed in this work. The ICF-AS-MFAC scheme is based on the concept of the pseudo partial derivative (PPD) and adopts equivalent dynamic linearization technology. Then, a tracking differentiator is used to predict the future output of a time-delay system to effectively control the system. Additionally, the concept of the saturation parameter is proposed, and the ICF-AS-MFAC controller is designed to ensure that the control system will not exhibit actuator saturation. The proposed algorithm is more flexible, has faster output responses for time-delay systems, and solves the problem of actuator saturation. The convergence and stability of the proposed method are rigorously proven mathematically. The effectiveness of the proposed method is verified by numerical simulations, and the applicability of the proposed method is verified by a series of experimental results based on double tanks.

4.
Evol Appl ; 16(2): 250-261, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36793691

RESUMO

Mesodermal development is essential to explore the interlineage variations in the development of spiralians. Compared with model mollusks such as Tritia and Crepidula, knowledge about the mesodermal development of other molluscan lineages is limited. Here, we investigated early mesodermal development in the patellogastropod Lottia goshimai, which shows equal cleavage and has a trochophore larva. The endomesoderm derived from the 4d blastomere, that is, the mesodermal bandlets, was situated dorsally and showed a characteristic morphology. Investigations of the potential mesodermal patterning genes revealed that twist1 and snail1 were expressed in a proportion of these endomesodermal tissues, while all of the five genes we investigated (twist1, twist2, snail1, snail2, and mox) were expressed in ventrally located ectomesodermal tissues. Relatively dynamic snail2 expression suggests additional roles in various internalization processes. By tracing snail2 expression in early gastrulae, the 3a211 and 3b211 blastomeres were suggested to be the precursors of the ectomesoderm, which elongated to become internalized before division. These results help to understand the variations in the mesodermal development of different spiralians and explore the different mechanisms by which ectomesodermal cells are internalized, which has important evolutionary implications.

5.
Clin Chem ; 68(12): 1541-1551, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36226750

RESUMO

BACKGROUND: Traditional phenotype-based screening for ß-globin variant and ß-thalassemia using hematological parameters is time-consuming with low-resolution detection. Development of a MALDI-TOF-MS assay using alternative markers is needed. METHODS: We constructed a MALDI-TOF-MS-based approach for identifying various ß-globin disorders and classifying thalassemia major (TM) and thalassemia intermedia (TI) patients using 901 training samples with known HBB/HBA genotypes. We then validated the accuracy of population screening and clinical classification in 2 separate cohorts consisting of 16 172 participants and 201 ß-thalassemia patients. Traditional methods were used as controls. Genetic tests were considered the gold standard for testing positive specimens. RESULTS: We established a prediction model for identifying different forms of ß-globin disorders in a single MALDI-TOF-MS test based on δ- to ß-globin, γ- to α-globin, γ- to ß-globin ratios, and/or the abnormal globin-chain patterns. Our validation study yielded comparable results of clinical specificity (99.89% vs 99.71%), and accuracy (99.78% vs 99.16%) between the new assay and traditional methods but higher clinical sensitivity for the new method (97.52% vs 88.01%). The new assay identified 22 additional abnormal hemoglobins in 69 individuals including 9 novel ones, and accurately screened for 9 carriers of deletional hereditary persistence of fetal hemoglobin or δß-thalassemia. TM and TI were well classified in 178 samples out of 201 ß-thalassemia patients. CONCLUSIONS: MALDI-TOF-MS is a highly accurate, predictive tool that could be suitable for large-scale screening and clinical classification of ß-globin disorders.


Assuntos
Hemoglobinas Anormais , Talassemia beta , Humanos , Globinas beta/genética , Talassemia beta/diagnóstico , Talassemia beta/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Hemoglobina Fetal , Hemoglobinas Anormais/análise , Proteínas de Transporte
6.
Insights Imaging ; 13(1): 144, 2022 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-36057694

RESUMO

OBJECTIVE: To develop and validate an 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT)-based radiomics nomogram for non-invasively prediction of bone marrow involvement (BMI) in pediatric neuroblastoma. METHODS: A total of 133 patients with neuroblastoma were retrospectively included and randomized into the training set (n = 93) and test set (n = 40). Radiomics features were extracted from both CT and PET images. The radiomics signature was developed. Independent clinical risk factors were identified using the univariate and multivariate logistic regression analyses to construct the clinical model. The clinical-radiomics model, which integrated the radiomics signature and the independent clinical risk factors, was constructed using multivariate logistic regression analysis and finally presented as a radiomics nomogram. The predictive performance of the clinical-radiomics model was evaluated by receiver operating characteristic curves, calibration curves and decision curve analysis (DCA). RESULTS: Twenty-five radiomics features were selected to construct the radiomics signature. Age at diagnosis, neuron-specific enolase and vanillylmandelic acid were identified as independent predictors to establish the clinical model. In the training set, the clinical-radiomics model outperformed the radiomics model or clinical model (AUC: 0.924 vs. 0.900, 0.875) in predicting the BMI, which was then confirmed in the test set (AUC: 0.925 vs. 0.893, 0.910). The calibration curve and DCA demonstrated that the radiomics nomogram had a good consistency and clinical utility. CONCLUSION: The 18F-FDG PET/CT-based radiomics nomogram which incorporates radiomics signature and independent clinical risk factors could non-invasively predict BMI in pediatric neuroblastoma.

7.
Eur J Radiol ; 154: 110444, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35917754

RESUMO

PURPOSE: To develop and validate an 18F-FDG PET/CT radiomics nomogram for non-invasive differentiation of high-risk and non-high-risk patients of the International Neuroblastoma Risk Group (INRG) Staging System (INRGSS). METHOD: One hundred thirty-nine neuroblastoma patients were retrospectively enrolled and classified into a training set (n = 84) and validation set (n = 55). Radiomics features were extracted from 18F-FDG PET/CT images, a radiomics signature was constructed, and a radiomics score (Rad score) was calculated. Then, univariate and multivariate logistic regression analyses were used to screen out the independent clinical factors and construct the clinical model. A radiomics nomogram was developed based on the Rad score and independent clinical factors. The performance of the clinical model, Rad score, and nomogram was assessed by receiver operating characteristic (ROC) curves, calibration curves, and decision curves analysis (DCA). RESULTS: Seven radiomics features were selected to build the radiomics signature. The age at diagnosis, the INRG stage, neuron-specific enolase (NSE) and Rad score showed a significant difference between the high-risk and non-high-risk patients. The radiomics nomogram incorporating the Rad score and the above clinical factors demonstrated favorable predictive value for differentiating high-risk from non-high-risk, yielded AUCs of 0.988 and 0.971 in the training and validation sets, respectively. The calibration curves showed that the radiomics nomogram had the goodness of fit, and the DCA demonstrated that the radiomics nomogram was clinically useful. CONCLUSIONS: The radiomics nomogram, which incorporates the Rad score and clinical factors can well predict high-risk and non-high-risk patients of the INRGSS. It may help the disease follow-up and management in clinical practice and assist in personalized and precise treatment of neuroblastoma.


Assuntos
Neuroblastoma , Nomogramas , Fluordesoxiglucose F18 , Humanos , Neuroblastoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
8.
Adv Sci (Weinh) ; 9(10): e2105869, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35112811

RESUMO

Transition metal nitrides have shown large potential in industrial application for realization of the high active and large current density toward overall water splitting, a strategy to synthesize an inexpensive electrocatalyst consisting of Ni nanoparticles embedded metallic MoN microrods cultured on roughened nickel sheet (Ni/MoN/rNS) through underfocus laser heating on NiMoO4 ·xH2 O under NH3 atmosphere is posited. The proposed laser preparation mechanism of infocus and underfocus modes confirms that the laser induced stress and local high temperature controllably and rapidly prepared the patterned Ni/MoN/rNS electrodes in large size. The designed Ni/MoN/rNS presents outstanding catalytic performance for hydrogen evolution reaction (HER) with a low overpotential of 67 mV to deliver a current density of 10 mA cm-2 and for the oxygen evolution reaction (OER) with a small overpotential of 533 mV to deliver 200 mA cm-2 . Density functional theory (DFT) calculations and Kelvin probe force microscopy (KPFM) further verify that the constructed interface of Ni/MoN with small hydrogen absorption Gibbs free energy (ΔGH* ) (-0.19 eV) and similar electrical conductivity between Ni and metallic MoN, which can explain the high intrinsic catalytic activity of Ni/MoN. Further, the constructed two-electrode system (-) Ni/MoN/rNS||Ni/MoN/rNS (+) is employed in an industrial water-splitting electrolyzer (460 mA cm-2 for 120 h), being superior to the performance of commercial nickel electrode.

9.
EJNMMI Res ; 11(1): 19, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33630176

RESUMO

PURPOSE: To develop and validate a machine learning model based on radiomic features derived from 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) images to preoperatively predict the pathological grade in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: A total of 149 patients (83 men, 66 women, mean age 61 years old) with pathologically proven PDAC and a preoperative 18F-FDG PET/CT scan between May 2009 and January 2016 were included in this retrospective study. The cohort of patients was divided into two separate groups for the training (99 patients) and validation (50 patients) in chronological order. Radiomics features were extracted from PET/CT images using Pyradiomics implemented in Python, and the XGBoost algorithm was used to build a prediction model. Conventional PET parameters, including standardized uptake value, metabolic tumor volume, and total lesion glycolysis, were also measured. The quality of the proposed model was appraised by means of receiver operating characteristics (ROC) and areas under the ROC curve (AUC). RESULTS: The prediction model based on a twelve-feature-combined radiomics signature could stratify PDAC patients into grade 1 and grade 2/3 groups with AUC of 0.994 in the training set and 0.921 in the validation set. CONCLUSION: The model developed is capable of predicting pathological differentiation grade of PDAC based on preoperative 18F-FDG PET/CT radiomics features.

10.
Light Sci Appl ; 9(1): 197, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33303741

RESUMO

Recently, integrated photonics has attracted considerable interest owing to its wide application in optical communication and quantum technologies. Among the numerous photonic materials, lithium niobate film on insulator (LNOI) has become a promising photonic platform owing to its electro-optic and nonlinear optical properties along with ultralow-loss and high-confinement nanophotonic lithium niobate waveguides fabricated by the complementary metal-oxide-semiconductor (CMOS)-compatible microstructure engineering of LNOI. Furthermore, ferroelectric domain engineering in combination with nanophotonic waveguides on LNOI is gradually accelerating the development of integrated nonlinear photonics, which will play an important role in quantum technologies because of its ability to be integrated with the generation, processing, and auxiliary detection of the quantum states of light. Herein, we review the recent progress in CMOS-compatible microstructure engineering and domain engineering of LNOI for integrated lithium niobate photonics involving photonic modulation and nonlinear photonics. We believe that the great progress in integrated photonics on LNOI will lead to a new generation of techniques. Thus, there remains an urgent need for efficient methods for the preparation of LNOI that are suitable for large-scale and low-cost manufacturing of integrated photonic devices and systems.

11.
ACS Appl Mater Interfaces ; 12(46): 51854-51863, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33151060

RESUMO

Manufacture of uniform, sensitive, and durable microtextured sensing materials is one of the greatest challenges for pressure sensors and electronic skins. Reported in this article is a gold nanoparticle-assembled, 3D-interconnected, graphene microchannel-embedded PDMS (3D GMC-PDMS) film for strain and pressure sensors. The film consists of porous nickel foam with its inner walls coated by multilayer graphene. Embedding in PDMS with etching removal of the Ni yields a 3D GMC-PDMS. Coating the inner walls with Au nanoparticles yields an Au nanoparticle-assembled 3D GMC-PDMS (AuNPs-GMC-PDMS) film, which is useful as an ultrasensitive pressure and strain sensor. This sensor exhibits a wide detection range (∼50 kPa) and ultrahigh sensitivity of 5.37, 1.56, and 0.5 kPa-1 in the ranges of <1, 1-10, and 10-50 kPa, respectively. Its lower detection limit is 4.4 Pa, its response time is 20 ms, and its strain factor is up to 15. Comparison of a AuNPs-GMC-PDMS film with a 3D GMC-PDMS film reveals a sensitivity improvement of 40 times in the 0-1 kPa pressure range and a gauge factor of more than 4 times in the 0-30% tensile strain range. The device has broad applications as a traditional or wearable medical sensor.

12.
ACS Appl Mater Interfaces ; 12(27): 30896-30904, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32515937

RESUMO

Flexible and piezoresistive electronic skins (E-skins) with high spatial resolution are highly desired in artificial intelligence and human-machine interactions. In this study, a simple method is developed to pattern a piezoresistive layer using lithography, which can realize real-time tactile sensing and spatial resolution. The piezoresistive layer with a honeycomb hole array based on polymethyl methacrylate (PMMA)/multiwalled carbon nanotubes (MWCNTs) was fabricated using a reverse mold with a ZnO nanorod array. The device exhibits an ultrahigh sensitivity of 88 kPa-1 in the low-pressure regime (<10 kPa) and a fast response time of 110 ms owing to the conductive honeycomb structure. The E-skin-based PMMA/MWCNT honeycomb array film can be applied to monitor bending and vibration by changing the contact area of the hole walls. A 4 × 4 piezoresistive matrix was fabricated by lithography for a 16-pixel tactile-sensing E-skin, which realizes a four-dimensional resolution including the space and time resolutions of pressure points. In addition, by using the unsymmetrical structure of an alveolate PMMA/MWCNT film, the detection of direction and velocity for the movement and gas flow were realized. The obtained piezoresistive and unsymmetrical tactile sensor realized a four-dimensional resolution, including a three-dimensional space and a fourth dimension of timeline, which enables future applications of human-machine interactions.

13.
Nanoscale ; 11(12): 5240-5246, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30864599

RESUMO

Complex nanostructures with high compositional and structural tailorability are highly desired in order to meet the material needs in the rapid development of nanoscience and nanotechnology. Therefore, the synthetic technique is of essential importance but currently still suffers from many challenges. Herein, we elaborately explore and demonstrate the flexibility of the anisotropic metallo-organic compound (dihafnium dichloride, Cp2HfCl2) for the fabrication of inorganic architectures by mimicking the assembly behaviors in biomolecules. The open and discrete architectures of mesoporous HfO2 nanoframes were constructed via the self-assembly of precursor with acetone as solvent and ammonia as the basic source, but without any addition of auxiliary organic molecules, like surfactants, DAN or peptides. In addition, the nanostructures (hollow spheres, solid spheres, yolk-shells, aggregations and defect-rich nanoparticles) of HfO2 assemblies can be well manipulated by simply modulating the synthesis parameters. The marked difference in the chemical bonds by the different ligands resulted in discrepant hydrolysis and then specific directional bonds for the diversity of the resultant HfO2 assemblies. Interestingly, the HfO2 nanoframe exhibits enhanced piezoelectricity, and can be used as a microelectrode reactor to trigger the pseudo-electrochemical aniline polymerization reaction by introducing ultrasonic excitation to renew the surface charges. Moreover, as compared with nanoparticle catalysts, the palladium (Pd) loaded nanoframe reactor exhibits obvious enhanced catalytic performance for classical Suzuki coupling, benefiting from the structural advantages of the HfO2 frame. Our findings here can be expected to offer new perspectives to find suitable materials by understanding the analogy between materials chemistry and biomolecule chemistry.

14.
Analyst ; 144(6): 2042-2051, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30714583

RESUMO

Glycosylation is a post-translational modification essential for maintaining the structure and function of proteins. Abnormal N-glycan patterns have been found in various diseases compared to healthy controls. A decrease in terminal galactosylated N-glycans of serum IgG in rheumatoid arthritis (RA) and osteoarthritis (OA) may be involved in their immunopathogenesis. However, how glycan patterns differ between RA and OA remains unclear. Here, we identified 15 glycan forms of serum IgG from RA and OA using MALDI-TOF MS. We found that IgG galactosylation represented a suitable candidate for differentiating RA from healthy controls (AUC > 0.9). Then, we performed binary logistic regression to screen out three bisecting N-acetylglucosamine (GlcNAc) glycoforms for distinguishing between OA and RA. Combined ROC analysis of the selected glycans yielded an AUC of 0.81 between OA and RA and an AUC of 0.79 between OA and RF/ACPA negative RA. Similar results were found in the validation set. In conclusion, our analysis demonstrates that RA and OA are distinguished on the basis of their different IgG glycan patterns, which thus serve as suitable candidates as biomarkers for reliably identifying clinical conditions such as RA and OA.


Assuntos
Artrite Reumatoide/diagnóstico , Biomarcadores/sangue , Galactose/química , Imunoglobulina G/sangue , Osteoartrite/diagnóstico , Polissacarídeos/sangue , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Idoso , Artrite Reumatoide/sangue , Estudos de Casos e Controles , Diagnóstico Diferencial , Feminino , Glicosilação , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/sangue , Processamento de Proteína Pós-Traducional
15.
Front Microbiol ; 9: 2149, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30254623

RESUMO

Foot-and-mouth disease virus (FMDV) has a wide host range. Its pathogenesis varies among hosts and types of viruses. Most investigations of pathogenesis have been performed on cattle and swine. However, FMDV research in cattle is hampered by the lack of a stable in vitro infection model. In this study, the stable bovine thyroid (BTY) cell line hTERT-BTY from primary BTY cells was established by telomerase reverse transcriptase over expression. The results of karyotype analysis and experiments on morphological and biological characteristics indicated that this cell line possessed the qualities of primary BTY cells, which could be extended indefinitely with stable morphology and steady growth rates. The hTERT-BTY cell line, has 60 chromosomes including 29 pairs of autosomes and 1 pair of sex chromosomes without structure aberrations. It can express thyroid-specific function genes thyroid-stimulating hormone receptor and sodium/iodide symporter in high abundance ratios. The cell line is sensitive to FMDV strains and is expected to be used as a powerful tool for FMDV clinical diagnosis, separation, detection and culture. Also, the different mRNA expression levels in infected and uninfected hTERT-BTY cells were analyzed in this study to identify the pathways of immunity using RNA-seq. The results suggested that the hTERT-BTY cell line could be regarded as an effective tool for the immune response exploration of FMDV. In conclusion, this study provided a useful tool for FMDV clinical diagnosis, separation, detection, and culture. The cell line also could serve as an in vitro model to study the mechanism underlying FMDV pathogenicity and host-virus interaction.

16.
Anal Bioanal Chem ; 409(15): 3731-3739, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28397166

RESUMO

An analytical method based on the combination of multistage mass spectrometry (MSn) and capillary electrophoresis (CE) was developed for the analysis of immunoglobulin G (IgG) glycosylation in rheumatoid arthritis (RA) patients. It has been recently suggested that IgG glycosylation defect may be involved in RA immunopathogenesis. Complete characterization of glycans, including both qualitative and quantitative analysis, requires a combination of different techniques, and accurate, robust, sensitive, and high-throughput methodologies are important for analysis of clinical samples. In the present study, N-glycosylation of IgG in RA patients and in healthy people was characterized through identification of the released glycans using multistage matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MSn), and quantitation by CE. Assignment of the IgG N-glycan structures was made through branching pattern analysis by MSn with high-throughput. Further accurate quantitation indicated that galactosylation and sialylation of IgG N-glycans in RA cases were significantly lower than in healthy subjects. The results indicate that CE coupled with MSn can identify abnormal glycosylation of IgG in RA patients compared with healthy people, and that the present work is useful for RA mechanism studies and RA diagnosis. Graphical Abstract Qualitative and quantitative analysis of IgG glycosylation in rheumatoid arthritis patients by MALDI-TOF-MSn and capillary electrophoresis.


Assuntos
Artrite Reumatoide/patologia , Imunoglobulina G/química , Polissacarídeos/análise , Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Eletroforese Capilar/métodos , Galactose/análise , Glicosilação , Humanos , Imunoglobulina G/sangue , Isomerismo , Pessoa de Meia-Idade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
17.
PLoS One ; 10(5): e0125828, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25946195

RESUMO

Viroporins are a family of low-molecular-weight hydrophobic transmembrane proteins that are encoded by various animal viruses. Viroporins form transmembrane pores in host cells via oligomerization, thereby destroying cellular homeostasis and inducing cytopathy for virus replication and virion release. Among the Picornaviridae family of viruses, the 2B protein encoded by enteroviruses is well understood, whereas the viroporin activity of the 2B protein encoded by the foot-and-mouth disease virus (FMDV) has not yet been described. An analysis of the FMDV 2B protein domains by computer-aided programs conducted in this study revealed that this protein may contain two transmembrane regions. Further biochemical, biophysical and functional studies revealed that the protein possesses a number of features typical of a viroporin when it is overexpressed in bacterial and mammalian cells as well as in FMDV-infected cells. The protein was found to be mainly localized in the endoplasmic reticulum (ER), with both the N- and C-terminal domains stretched into the cytosol. It exhibited cytotoxicity in Escherichia coli, which attenuated 2B protein expression. The release of virions from cells infected with FMDV was inhibited by amantadine, a viroporin inhibitor. The 2B protein monomers interacted with each other to form both intracellular and extracellular oligomers. The Ca(2+) concentration in the cells increased, and the integrity of the cytoplasmic membrane was disrupted in cells that expressed the 2B protein. Moreover, the 2B protein induced intense autophagy in host cells. All of the results of this study demonstrate that the FMDV 2B protein has properties that are also found in other viroporins and may be involved in the infection mechanism of FMDV.


Assuntos
Autofagia/genética , Membrana Celular/metabolismo , Vírus da Febre Aftosa/metabolismo , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas Virais Reguladoras e Acessórias/antagonistas & inibidores , Amantadina/farmacologia , Animais , Cálcio/metabolismo , Linhagem Celular , Permeabilidade da Membrana Celular , Cricetinae , Retículo Endoplasmático/virologia , Escherichia coli/virologia , Vírus da Febre Aftosa/genética , Humanos , Estrutura Terciária de Proteína , Liberação de Vírus/efeitos dos fármacos , Replicação Viral/fisiologia
18.
Arch Microbiol ; 197(4): 621-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25690604

RESUMO

Canine parvovirus (CPV) can cause acute hemorrhagic diarrhea and fatal myocarditis in young dogs. Currently, most studies have focused on the evolution of the VP2 gene, whereas the full-length genome of CPV has been rarely reported. In this study, the whole genomes of CPV-LZ1 and CPV-LZ2 strains prevalent in Northwest China were determined and analyzed in comparison with those of the reference CPVs. The genome sequences of both LZ strains consisted of 5053 nucleotides. CPV-LZ1 and CPV-LZ2 strains were designated as new CPV-2a and CPV-2b, respectively. Sequence alignment analysis results revealed that these two new strains underwent specific unique variations during the process of local adaption. The left non-translated regions of these strains formed a Y-shaped hairpin structure, whereas the right non-translated regions lacked the reiteration of DNA sequence. A phylogenetic tree constructed from 33 whole coding regions of CPVs showed a strong spatial clustering, and these two strains belonged to the Chinese strain cluster lineage. This study provides a method to obtain the full-length genome of CPV. The isolation and characterization of these viruses adds incrementally to the knowledge of the full-length genome of CPV. The results from this study also provide insight into the molecular epidemiology and genetic diversity of the CPV field isolates from Northwest China and can be useful in preventing and controlling CPV infection in this region.


Assuntos
Proteínas do Capsídeo/genética , Doenças do Cão/virologia , Infecções por Parvoviridae/veterinária , Parvovirus Canino/genética , Proteínas não Estruturais Virais/genética , Animais , Sequência de Bases , China , Cães , Variação Genética , Genoma/genética , Dados de Sequência Molecular , Infecções por Parvoviridae/virologia , Filogenia , Prevalência , Alinhamento de Sequência , Análise de Sequência , Análise de Sequência de DNA
19.
Adv Healthc Mater ; 4(7): 998-1003, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25663267

RESUMO

Polarized ferroelectric crystal lithium niobate wafers with different cuts are selected to offer differently charged surfaces. By induction of the mesenchymal stem cells differentiation into osteoblasts on different charged surfaces, the specific osteogenic-associated markers are assessed and the results illustrate that the positively charged wafer surface enhances rBMMSCs osteogenic differentiation.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Mesenquimais/fisiologia , Osteoblastos/fisiologia , Osteogênese/fisiologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Nióbio/farmacologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Óxidos/farmacologia
20.
Microsc Res Tech ; 77(4): 289-95, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24481988

RESUMO

Autofocusing technology is indispensable for routine use of microscopes on a large scale in biological field. The autofocusing method using the angle of Hilbert space is brought forward to measure whether the image is focused or not. The angle of Hillbert space can be used to evaluate accurately the similarity degree of two images. The experiment results show that the autofocusing method can decrease the computational cost and get accuracy for real-time biological and biomedical images with noise robustness. The focus curves are smooth and possess the unimodality, the monotonicity and the symmetry. Compared with other classic and optimum focus method, the Hilbert method demonstrates its robustness to noise and can improve the focus speed. The experiments showed that the proposed method can increase the overall performance of an autofocus system and has strong applicability in various autofocusing algorithms.


Assuntos
Automação/métodos , Microscopia/instrumentação , Algoritmos , Animais , Automação/instrumentação , Linhagem Celular , Cricetinae , Humanos , Processamento de Imagem Assistida por Computador
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...