A cross-sectional serum investigation of a clustering hepatitis C virus infection in Southwest China

Serum samples were collected in a village with a clustering hepatitis C virus (HCV) infection. HCV antibody, HCV RNA loads, liver function indexes, HCV envelope antibody, and neutralizing activity were assessed. Among 851 adult sera, 342 samples were positive for anti-HCV. Of these positive samples, 254 (74.3%) were HCV RNA positive (≥800 copies/mL). None of the 69 children's sera were positive for HCV antibody or RNA. Among the HCV antibody positive sera, alanine aminotransferase, and aspartate aminotransferase levels increased with the higher virus loads, but decreased when virus loads were higher than 1 × 10 ⁶ copies/mL. HCV envelope antibody and neutralizing antibody levels increased with viral load.     

Spatial and seasonal bacterioplankton community dynamics in the main channel of the Middle Route of South-to-North Water Diversion Project

In this study, the spatial and seasonal bacterioplankton community dynamics were investigated in the main channel of the Middle Route of the South-to-North Water Diversion Project (MRP) using Illumina HiSeq sequencing. Water samples were collected in spring and summer from south to north at eight water quality monitoring stations, respectively. The results showed that seasonal changes had a more pronounced effect on the bacterioplankton community compositions (BCCs) than spatial variation. The diversity analysis results indicated that samples of summer have more operational taxonomic units (OTUs), higher richness and diversity than those in spring. The main phyla, Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and Chloroflexi, displayed significant differences (P < 0.05) between spring and summer in the main channel. The Redundancy analysis (RDA) targeting all samples indicated that specific conductivity (SPC), dissolved oxygen (DO), pH and temperature (T) might be key factors in driving BCCs, while trophic status showed no significant correlation (P > 0.05). The present study provides important insights into the potential ecological roles of specific taxa in the new artificial ecosystem and it offers reference for studies on ecosystem succession of other giant interbasin water diversion project in the world.     

Efficient Production of High‐Quality Polystyrene‐Functionalized Graphene via Graphite Exfoliation in Chloroform with a Heterobifunctional Hyperbranched Polyethylene as Stabilizer

Efficient production of high‐quality, functionalized graphene is highly desirable for large‐scale applications of graphene. Herein, a route for producing high‐quality, polystyrene (PS)‐functionalized graphene is demonstrated via graphite exfoliation in chloroform with a heterobifunctional hyperbranched polyethylene, HBPE@Py@PS, as stabilizer. The HBPE@Py@PS, possessing a pyrene‐functionalized hyperbranched polyethylene backbone and multiple PS side chains, is synthesized by combining chain walking polymerization and atom transfer radical polymerization techniques. It is confirmed that the HBPE@Py@PS can effectively promote graphite exfoliation in chloroform under sonication to render stable dispersions of high‐quality graphene, with an exfoliation efficiency high as 15% and a monolayer proportion, 61%. Meanwhile, it can irreversibly adsorb on the exfoliated graphene surface based on the π–π stacking interactions, concurrently rendering PS‐functionalized graphene that is fluorescent and highly dispersible in chloroform, with a film conductivity reaching 1100 S m^?1. The as‐produced graphene may find its applications as nanofiller for various PS‐based graphene nanocomposites.     

Effect of Dibutyl Phthalate on the Tolerance and Lipid Accumulation in the Green Microalgae <Emphasis Type="Italic">Chlorella vulgaris</Emphasis>

Offshore oil exploration creates threats to coastal ecosystems, including increasing urbanization and associated effluent releases. Genotoxicity biomarkers in mussels were determined across a gradient of coastal zone influences of offshore petroleum exploration in southeastern Brazil. Coastal ecosystems such as estuaries, beaches and islands were seasonally monitored for genotoxicity evaluation using the brown mussel Perna perna. The greatest DNA damage (5.2%?±?1.9% tail DNA and 1.5‰? ±?0.8‰ MN) were observed in urban estuaries, while Santana Archipelago showed levels of genotoxicity near zero and is considered a reference site. Mussels from urban and pristine beaches showed intermediate damage levels, but were also influenced by urbanization. Thus, mussel genotoxicity biomarkers greatly indicated the proposed oil exploration and urbanization scenarios that consequently are genetically affecting coastal organisms.     

Actinomyces spp. in supragingival plaque of ethnic Chinese preschool children with and without active dental caries

Very limited molecular epidemiological data are available on the role of Actinomyces spp. in the pathogenesis of caries in the primary dentition. Therefore, we investigated their distribution in supragingival plaque of ethnic Chinese preschool children from Singapore and Hong Kong, either with or without active caries. Plaque samples were taken from intact interproximal enamel areas using dental floss. Bacterial genomic DNA of each sample was extracted and variable regions of 16S ribosomal DNA amplified and labelled with digoxigenin. Oligonucleotide probes specific for Actinomyces bovis, Actinomyces gerencseriae, Actinomyces israelii, Actinomyces meyeri, Actinomyces odontolyticus, catalase-negative Actinomyces naeslundii (genospecies 1 and 2) and catalase-positive Actinomyces naeslundii genospecies 2 (previously Actinomyces viscosus serotype II) were used to detect these species using Southern hybridization with a Minislot and Miniblotter system. A. odontolyticus, A. gerencseriae and A. meyeri were detected with similar frequency in both Singapore and Hong Kong samples or in those with and without active caries. However, the prevalence of A. naeslundii was significantly different in the two locales (p<0.05). A. odontolyticus (88.7%), A. gerencseriae (56.6%) and A. naeslundii (50.9%) were detected in a majority of the samples and the positive hybridization signals of A. gerencseriae in the caries-active group were stronger than from the caries-free group. A. bovis and A. israelii were undetectable in any of the samples. These data imply that A. odontolyticus, A. naeslundii and A. gerencseriae may play an important role in supragingival plaque formation on primary teeth in ethnic Chinese, with others such as A. meyeri contributing.     

根管侧壁穿孔的修补及桩冠的临床探索

对２０例，２１个有根壁侧穿，并伴有根周脓肿或窦道的患牙，重新进行根管清理、预备、消毒，达到根充指征时，即采用氢氧化钙加碘仿糊剂修补侧壁穿孔，同时加牙胶尖进行根充，３～４周后，采用铸造基底背板桩行桩冠修复患牙，取得了较为满意的效果。     

Human ameloblastoma tumors express the amelogenin gene.

Instructive signals are responsible for the regulation of the expression of gene products characteristic of many cell lineages during normal development and potentially during neoplasia. The odontogenic origin of ameloblastomas is based largely on the similarity in histologic appearance between the tumor and the developing tooth organ. A pathognomonic pattern for odontogenic tissue-specific gene expression in ameloblastomas has not been previously shown. In these studies, the gene expression parameters for human ameloblastomas have been characterized with the techniques of messenger RNA phenotyping in combination with Northern and in situ hybridization analysis of messenger RNA. The results of these studies confirm that amelogenin, a gene transcribed solely by differentiated ameloblasts, was expressed by epithelial cells from human ameloblastomas. This observation suggests that the instructive signals required for ameloblast differentiation are shared during normal development and tumorigenesis of odontogenic epithelium.