[Infectivity of Human Adenovirus Type 55 to Human Intestinal Cells].

OBJECTIVE: To examine the infectivity of human adenovirus type 55 (HAdV-55) in human intestinal cells. METHODS: Caco-2 cells were cultured in vitro, and infected with HAdV-3, 7, 14 and 55. The expression of viral proteins in infected cells was detected with immunofluorescence method. The intracellular and supernatant viral DNA levels were determined with fluorescent quantitative PCR at different points of time. The level of infectious virus particles in the supernatant of Caco-2 cells was determined with adenovirus sensitive HEp-2 infection assay. RESULTS: Immunofluorescence assay showed positive result for the expression of HAdV-55 virus protein in Caco-2 cells 48 h post infection. HAdV-3, 7, 14, and 55 showed sustained replication and proliferation in Caco-2 cells. The level of viral DNA in infected cells and the supernatant increased with the infection time, and the viral DNA level of HAdV-55 was significantly higher than those of HAdV-3, 7 and 14. The infectious virus particles of HAdV-55 in Caco-2 supernatant were more than those of HAdV-3, 7 and 14, showing statistically significant difference ( P<0.05). Caco-2 cells were infected with low doses of virus (1×TCID 50), and the cytopathic effect (CPE) of HAdV-55 infection wells was more significant than that of HAdV-3, 7 and 14 infection wells. CONCLUSION: This study found that human intestinal cells were susceptible to HAdV-55, and the infection level was higher than that of other common respiratory infections caused by adenovirus types 3, 7 and 14.

Identification and evaluation of protection effect of B-cell immunodominant epitopes of campylobacter jejuni PEB1.

To provide detail data for Campylobacter jejuni (C.jejuni) vaccine research, this study performed epitope prediction analysis technology to screen the B cell immunodominant epitopes of C. jejuni adhesion protein PEB1 and evaluated the immunoprotective effect. The overlapping peptides were synthesized and B-cell immunodominant epitopes of PEB1 were identified by ELISA. BALB/c mice were immunized with the immunodominant epitopes of PEB1 conjugated with KLH plus CFA/IFA. The titers for immunodominant peptide antiserum against PEB1 were detected by ELISA. The bacterial colonization and the relative expression level of TNF-α were analyzed after the mice challenged with C. jejuni 11,168. The function of antibody induced by immunodominant PEB1 epitopes were performed by opsonophagocytic killing. The results showed that PEB155-72aa, PEB197-114aa, PEB1211-228aa were the immunodominant peptides and could induce strong B cell mediated humoral immunity response. Antiserum from the immunodominant peptides group significantly enhanced opsonize phagocytosis than CFA/IFA group (P<0.01). Both the bacterial burdens and the TNF-α expression level in the immunodominant peptides groups were significantly lower than those in the control group (P<0.01). Moreover, the immune protective effect of the three immunodominant peptides depended on the B cell immunity response in vivo study. In conclusion, three specific B cell immunodominant epitopes with good immunogenicity and immunoprotection efficacy were successfully identified, indicating that could be used in the anti- C. jejuni vaccine research and development.

Morphology and Molecular Analysis of Moesziomyces antarcticus Isolated From the Blood Samples of a Chinese Patient.

Objective: To identify the pathogen causing fungemia in a Chinese patient and describe its morphological and molecular characterizes. Methods: Samples of central and peripheral venous blood were collected for blood culture. Morphology and drug sensitivities of the isolated yeast-like fungus were analyzed. rDNA sequencing and molecular phylogenetic analysis of the isolated strains were performed using DNAMAN and MEGA software. Results: A strain of yeast-like fungi was repeatedly isolated from blood samples of a Chinese patient. The isolates grew well on sabouraud medium broth plate. The colonies were smooth and round at 28°C, and were of rough surface and irregular shape at 35°C. Molecular phylogenetic trees constructed based on the internal transcribed spacer (ITS) and D1/D2 domains of 28S rDNA gene demonstrated the isolated yeast-like fungus was Moesziomyces antarcticus. Drug susceptibility test showed that this isolated M. antarcticus was resistant or had relatively low susceptibility to flucytosine, fluconazole, voriconazole, and itraconazole, and only sensitive to amphotericin. Conclusion: This study provided more information for the molecular and morphology characteristics of M. antarcticus and reviewed the species information of Moesziomyces associated with human infections, which will contribute to the identification and diagnosis of Moesziomyces infections.

Hepatitis C Virus Entry into Macrophages/Monocytes Mainly Depends on the Phagocytosis of Macrophages.

BACKGROUND: Hepatitis C virus (HCV) has been classified as a strictly hepatotropic pathogen for a long time, and hepatocytes are target cells for HCV infection. More and more studies showed non-liver cells supported HCV entry and replication, such as macrophages. The mechanisms of HCV entry into macrophages are still not clear. AIMS: This study aims to determine the way of HCV entry into macrophages. METHODS: Cell culture-derived infectious HCV particles (HCVcc) were prepared using Huh7 cells transfected with HCV RNA. CD81-knockdown cells were obtained through siRNA transfection. HCV RNA levels were determined by RT-qPCR. Flow cytometry analyses were used to determine cell surface levels of CD11b, CD68, and CD81. ELISA and western blotting were performed to quantify the protein levels of IL-1ß, IL-6, and TNF-α. Phagocytic ability was determined by neutral red uptake assay. RESULTS: CD81 knockdown could not inhibit HCVcc entry into macrophages. The entry of HCV into macrophages could not be blocked by pooled IgG from chronic hepatitis C patient's sera. Macrophages derived from THP-1 cells displayed stronger phagocytic capacity, which also swallowed more HCV RNA. Treatment of macrophages with endocytic inhibitor, methyl-ß-cyclodextrin, decreased the internalization of HCV. HCV uptake by macrophages was related to the reorganization of F-actin cytoskeleton and PI3Ks activation. HCV infection significantly increased the expression of IL1ß and IL6 in macrophages and promoted apoptosis of macrophages. CONCLUSIONS: HCV entry into macrophages mainly depends on phagocytosis of macrophages.

Hybrid graphene/GaN ultraviolet photo-transistors with high responsivity and speed.

In this work, we explore the possibility of using hybrid graphene/GaN phototransistors to get high responsivity, high speed, and large photosensitive area. The responsivity of our hybrid graphene/GaN phototransistors with a relatively large 15.2 mm2 active area reaches 361 mA/W at 10 V and the response time is ~5 ms, much better performance than traditional GaN photodetectors. This is because graphene acts as the carrier transport channel with a high mobility and greatly increases the charge collection efficiency. Our results should shed more light on the role of graphene in hybrid phototransistors and open a feasible pathway to develop large area ultraviolet photodetectors with high responsivity and high speed.

Greatly Enhanced Anticorrosion of Cu by Commensurate Graphene Coating.

Metal corrosion is a long-lasting problem in history and ultrahigh anticorrosion is one ultimate pursuit in the metal-related industry. Graphene, in principle, can be a revolutionary material for anticorrosion due to its excellent impermeability to any molecule or ion (except for protons). However, in real applications, it is found that the metallic graphene forms an electrochemical circuit with the protected metals to accelerate the corrosion once the corrosive fluids leaks into the interface. Therefore, whether graphene can be used as an excellent anticorrosion material is under intense debate now. Here, graphene-coated Cu is employed to investigate the facet-dependent anticorrosion of metals. It is demonstrated that as-grown graphene can protect Cu(111) surface from oxidation in humid air lasting for more than 2.5 years, in sharp contrast with the accelerated oxidation of graphene-coated Cu(100) surface. Further atomic-scale characterization and ab initio calculations reveal that the strong interfacial coupling of the commensurate graphene/Cu(111) prevents H2 O diffusion into the graphene/Cu(111) interface, but the one-dimensional wrinkles formed in the incommensurate graphene on Cu(100) can facilitate the H2 O diffusion at the interface. This study resolves the contradiction on the anticorrosion capacity of graphene and opens a new opportunity for ultrahigh metal anticorrosion through commensurate graphene coating.

Wafer-Scale Growth and Transfer of Highly-Oriented Monolayer MoS2 Continuous Films.

Large scale epitaxial growth and transfer of monolayer MoS2 has attracted great attention in recent years. Here, we report the wafer-scale epitaxial growth of highly oriented continuous and uniform monolayer MoS2 films on single-crystalline sapphire wafers by chemical vapor deposition (CVD) method. The epitaxial film is of high quality and stitched by many 0°, 60° domains and 60°-domain boundaries. Moreover, such wafer-scale monolayer MoS2 films can be transferred and stacked by a simple stamp-transfer process, and the substrate is reusable for subsequent growth. Our progress would facilitate the scalable fabrication of various electronic, valleytronic, and optoelectronic devices for practical applications.

Monocyte chemoattractant protein 1 released from macrophages induced by hepatitis C virus promotes monocytes migration.

Hepatitis C Virus (HCV) infection usually progress to chronic liver disease and shows a significant increase in total monocyte/macrophages numbers in the liver. Monocyte chemoattractant protein-1 (MCP-1) plays a role in the recruitment of monocytes to the liver. In this study we found that MCP-1 were up-regulated in macrophages cultured with cell-culture derived infectious HCV particles (HCVcc) and promoted the migration of monocytes. IL1ß, IL6 and TNFα were factors that induced MCP-1 expression, which were up-regulated in macrophages induced by HCV. Long-term of HCV incubation induced apoptosis of macrophages. Finally, we observed the effect of HCV infected macrophages on nearby liver cells. Huh7 cells continuously co-cultured with monocyte/macrophages displayed increased expression of pro-inflammatory cytokines and the morphology of Huh7 cells were greatly changed. Taken together, our study provides more information for the role of monocyte/macrophages in HCV related chronic liver disease.

Ultrafast growth of single-crystal graphene assisted by a continuous oxygen supply.

Graphene has a range of unique physical properties and could be of use in the development of a variety of electronic, photonic and photovoltaic devices. For most applications, large-area high-quality graphene films are required and chemical vapour deposition (CVD) synthesis of graphene on copper surfaces has been of particular interest due to its simplicity and cost effectiveness. However, the rates of growth for graphene by CVD on copper are less than 0.4 µm s-1, and therefore the synthesis of large, single-crystal graphene domains takes at least a few hours. Here, we show that single-crystal graphene can be grown on copper foils with a growth rate of 60 µm s-1. Our high growth rate is achieved by placing the copper foil above an oxide substrate with a gap of ∼15 µm between them. The oxide substrate provides a continuous supply of oxygen to the surface of the copper catalyst during the CVD growth, which significantly lowers the energy barrier to the decomposition of the carbon feedstock and increases the growth rate. With this approach, we are able to grow single-crystal graphene domains with a lateral size of 0.3 mm in just 5 s.

High-responsivity vertical-illumination Si/Ge uni-traveling-carrier photodiodes based on silicon-on-insulator substrate.

Si/Ge uni-traveling carrier photodiodes exhibit higher output current when space-charge effect is overcome and the thermal effects is suppressed. High current is beneficial for increasing the dynamic range of various microwave photonic systems and simplifying high-bit-rate digital receivers in many applications. From the point of view of packaging, detectors with vertical-illumination configuration can be easily handled by pick-and-place tools and are a popular choice for making photo-receiver modules. However, vertical-illumination Si/Ge uni-traveling carrier (UTC) devices suffer from inter-constraint between high speed and high responsivity. Here, we report a high responsivity vertical-illumination Si/Ge UTC photodiode based on a silicon-on-insulator substrate. When the transmission of the monolayer anti-reflection coating was maximum, the maximum absorption efficiency of the devices was 1.45 times greater than the silicon substrate owing to constructive interference. The Si/Ge UTC photodiode had a dominant responsivity at 1550 nm of 0.18 A/W, a 50% improvement even with a 25% thinner Ge absorption layer.

Hepatitis C virus infection induces elevation of CXCL10 in human brain microvascular endothelial cells.

Hepatitis C virus (HCV) primarily infects liver tissues, while pathogenesis of extrahepatic tissues has been reported. About 50% of patients with HCV infection suffer from neurological disease. The underlying molecular mechanisms remain unclear. In the present study, we aimed to investigate the induction of CXC chemokine ligand 10 (CXCL10) in human brain microvascular endothelial cells (HBMECs) by HCV infection. CXCL10 and its receptor CXCR3 were constitutively expressed in HBMECs. HCV infection induced CXCL10 elevation in HBMECs. The elevation of CXCL10 in HBMECs was eliminated when HCV infection was blocked by neutralizing antibodies. NF-κB is a positive regulator for CXCL10 transcription. HCV infection led to an increased phosphorylation of NF-κB (ser536) in HBMECs, and CXCL10 induced by HCV was slightly decreased when an inhibitor of NF-κB was added. IL1 beta and IFN gama were also upregulated in HCV infected HBMECs, and could be depressed by inhibitor of NF-κB. Thus, HCV infection leads to upregulated expression of CXCL10 in HBMECs, which is probably via the phosphorylation of NF-κB. The findings of this study provide potential mechanisms and novel targets for HCV induced neuroinflammation. J. Med. Virol. 88:1596-1603, 2016. © 2016 Wiley Periodicals, Inc.

LRRFIP1 Inhibits Hepatitis C Virus Replication by Inducing Type I Interferon in Hepatocytes.

BACKGROUND: Hepatitis C virus infection is one of the leading causes of end stage liver diseases. The innate immune response slows down viral replication by activating cytokines such as type I interferon (IFN-α/ß), which trigger the synthesis of antiviral proteins and modulate the adaptive immune system. Recently, leucine-rich repeat (in Flightless I) interacting protein-1 (LRRFIP1) was reported contributing to the production of interferon-ß in macrophages. OBJECTIVES: The aim of this study was to assess the role of LRRFIP1 in induction of IFN-ß and inhibition of HCV infection in hepatocytes. MATERIALS AND METHODS: Induction of IFN-ß by LRRFIP1 in Huh7 and Huh7.5.1 was determined by real-time PCR and western blotting in vitro. Inhibition of HCV replication by LRRFIP1 overexpression in hepatocytes was assessed. RESULTS: LRRFIP1 increased the expression of IFN-ß in hepatocytes with or without HCV infection. Induction of IFN-ß by LRRFIP1 was enhanced with the presence of hepatitis C virus. Overexpression of LRRFIP1 in hepatocytes inhibited HCV replication. However, HCV infection did not regulate intracellular expression of LRRFIP1. CONCLUSIONS: LRRFIP1 and its mediated production of type I interferon play a role in controlling HCV infection. The findings of this study provide new target for HCV treatment and contribute to development of anti-HCV drugs.

Whole genome sequence of Enterobacter ludwigii type strain EN-119T, isolated from clinical specimens.

Enterobacter ludwigii strain EN-119(T) is the type strain of E. ludwigii, which belongs to the E. cloacae complex (Ecc). This strain was first reported and nominated in 2005 and later been found in many hospitals. In this paper, the whole genome sequencing of this strain was carried out. The total genome size of EN-119(T) is 4952,770 bp with 4578 coding sequences, 88 tRNAs and 10 rRNAs. The genome sequence of EN-119(T) is the first whole genome sequence of E. ludwigii, which will further our understanding of Ecc.

Direct observation of ordered configurations of hydrogen adatoms on graphene.

Ordered configurations of hydrogen adatoms on graphene have long been proposed, calculated, and searched for. Here, we report direct observation of several ordered configurations of H adatoms on graphene by scanning tunneling microscopy. On the top side of the graphene plane, H atoms in the configurations appear to stick to carbon atoms in the same sublattice. Scanning tunneling spectroscopy measurements revealed a substantial gap in the local density of states in H-contained regions as well as in-gap states below the conduction band due to the incompleteness of H ordering. These findings can be well explained by density functional theory calculations based on double-sided H configurations. In addition, factors that may influence H ordering are discussed.

CXCL10 decreases GP73 expression in hepatoma cells at the early stage of hepatitis C virus (HCV) infection.

Golgi protein 73 (GP73), which is up-regulated in hepatocellular carcinoma (HCC), has recently been identified as a novel serum marker for HCC diagnosis. Several reports also noted the increased levels of GP73 expression in chronic liver disease in patients with acute hepatitis of various etiologies, chronic Hepatitis C virus (HCV) infection and alcoholic liver disease. The molecular mechanisms of GP73 expression in HCV related liver disease still need to be determined. In this study, we aimed to evaluate the effect of HCV infection on GP73 expression. GP73 was highly expressed in Huh7, Hep3B, 293T and HUVEC cells, and was low-expressed in HepG2 cells. HCV infection led to down-regulation of GP73 in Huh7 and HepG2/CD81 cells at the early stage of infection. CXCL10 decreased GP73 expression in Huh7 and HepG2 cells. Up-regulation of GP73 was noted in hepatocytes with cytopathic effect at advanced stage of HCV infection, and further research is needed to determine the unknown factors affecting GP73 expression. In conclusion, our study provided additional evidence for the roles of GP73 in liver disease.

Competing thermodynamic and dynamic factors select molecular assemblies on a gold surface.

Controlling the self-assembly of surface-adsorbed molecules into nanostructures requires understanding physical mechanisms that act across multiple length and time scales. By combining scanning tunneling microscopy with hierarchical ab initio and statistical mechanical modeling of 1,4-substituted benzenediamine (BDA) molecules adsorbed on a gold (111) surface, we demonstrate that apparently simple nanostructures are selected by a subtle competition of thermodynamics and dynamics. Of the collection of possible BDA nanostructures mechanically stabilized by hydrogen bonding, the interplay of intermolecular forces, surface modulation, and assembly dynamics select at low temperature a particular subset: low free energy oriented linear chains of monomers and high free energy branched chains.

Electric-field-driven accumulation and alignment of CdSe and CdTe nanorods in nanoscale devices.

Local electric fields generated by nanopatterned electrodes were used to control the position and orientation of well-isolated as well as closely packed colloidal semiconducting CdTe and CdSe nanorods (NRs) drop-cast from solution. Postdeposition imaging using transmission-electron microscopy and atomic-force microscopy revealed strong NR alignment to the direction of the applied field and dense accumulation around and onto voltage-biased electrodes when deposited from dilute and concentrated solutions, respectively. The degree of alignment under the applied electric field is characterized by a nematic order parameter S approximately 0.8 in contrast to the zero-field case when S approximately 0.1.

Local charge transport in two-dimensional PbSe nanocrystal arrays studied by electrostatic force microscopy.

Two-dimensional PbSe nanocrystal arrays on silicon nitride membranes were investigated using electrostatic force microscopy (EFM) and transmission electron microscopy (TEM). Changes in lattice and transport properties upon annealing in a vacuum were revealed. Local charge transport behavior was directly imaged by EFM and correlated to nanopatterns observed with TEM. Charge transport through nanochannels in complex two-dimensional nanocrystal networks was identified. Our results demonstrate the importance of measurements of local transport details complementary to the conventional current-voltage (I-V) measurements.