课程文献中心 更多>>

关键词： metformin   macrophage   polarization   Notch   inflammation   hepatoma  

摘要： Objective Accumulating evidence suggests an association between diabetes and cancer. Inflammation is a key event that underlies the pathological processes of the two diseases. Metformin displays anti-cancer effects, but the mechanism is not completely clear. This study investigated whether metformin regulated the microenvironment of macrophage polarization to affect the characteristics of HepG2 cells and the possible role of the Notch-signalling pathway. Methods RAW264.7 macrophages were cultured alone or co-cultured with HepG2 cells and treated with metformin. We analysed classical (M1) and alternative (M2) gene expression in RAW264.7 cells using quantitative real-time polymerase chain reaction. Changes in mRNA and protein expressions of Notch signalling in both cell types were also detected using quantitative real-time polymerase chain reaction and Western-blotting analyses. The proliferation, apoptosis and migration of HepG2 cells were detected using Cell Titer 96 AQueous One Solution Cell Proliferation Assay (MTS) (Promega Corporation, Fitchburg, WI, USA), Annexin V-FITC/PI (7SeaPharmTech, Shanghai, China) and the cell scratch assay, respectively. Results Metformin induced single-cultured RAW264.7 macrophages with an M2 phenotype but attenuated the M2 macrophage differentiation and inhibited monocyte chemoattractant protein-1 (MCP-1) secretion in a co-culture system. The co-cultured group of metformin pretreatment activated Notch signalling in macrophages but repressed it in HepG2 cells. Co-culture also promoted the proliferation and migration of HepG2 cells. However, along with the enhanced apoptosis, the proliferation and the migration of HepG2 cells were remarkably inhibited in another co-culture system with metformin pretreatment. Conclusions Metformin can skew RAW264.7 macrophages toward different phenotypes according to changes in the microenvironment, which may affect the inflammatory conditions mediated by macrophages, induce apoptosis and inhibit the pr

关键词： Environmental surveillance   Poliovirus   Nigeria   Enterovirus species B bias   Diversity landscape  

摘要： Despite its widespread use in poliovirus isolation, studies show that most RD cell line isolates are species B enteroviruses (EB), it was therefore employed to further catalogue the EB diversity in two different regions of Nigeria. Concentrates of 18 environmental samples were inoculated into RD cell line. Isolates were subjected to PCR assays to detect enteroviruses, species C and B members and partial VP1 gene which was subsequently sequenced and used for identification and phylogenetic analysis. Isolates were further passaged in L20B cell line to detect polioviruses. Sixty-eight isolates were recovered from the 18 concentrates, all of which were positive for the enterovirus 5'-UTR screen. Thirteen of the 68 isolates were positive for the species C screen and replicated in L20B cell line, eleven of which also contained species B enteroviruses. Some of the mixed isolates were successfully typed, but as species B members. In all, isolates recovered in this study were identified as CVB5, E6, E7, E11, E13, E19, E20, E33, EVB75 and WPV3, while some could not be typed. Alongside the ten different enterovirus serotypes confirmed, results of this study document for the first time in Nigeria, EVB75. It showed the EB bias of RD cell line might indicate something much more fundamental in its biology. Finally, the finding of WPV3 in a region considered low risk for poliovirus emphasizes the need to expand poliovirus environmental surveillance to enable early detection of poliovirus silent circulation before occurrence of clinical manifestations.

关键词： iron   line-imaging   line-imaging velocimetry   heterodyne velocimetry   continuous wavelet transform   velocity interferometer system for any reflector (VISAR)   plate impact  

摘要： A single streak camera line imaging velocimeter has been applied to Armco (R) iron plate impact experiments to study material response at the grain scale. The grain size and phase distribution were determined with electron back scatter diffraction. The optical system resolution and fringe size were optimised to suit the grain size distribution. Comparisons of the performance and merits of several analysis algorithms including the 'Fourier transform', 'fringe tracking', 'quadrature' and the 'continuous wavelet transform' have been made by application to synthetic data. Point heterodyne velocimetry measurements made at the same location on the target surface have been compared with the line imaging velocimetry data for confirmation.

关键词： Packing line   Blueberry   Instrumented sphere   Impact recording device   Bruising   Mechanical damage   Vaccinium  

摘要： Blueberry fruit is susceptible to bruising from mechanical impact. Bruised fruit has shorter postharvest shelf life and softens rapidly in cold storage than non-bruised fruit. A blueberry packing line consists of a hopper for transferring fruit in field containers onto a conveyor line that moves fruit into trash removal equipment, electronic sorter, inspection line, and finally onto clamshell-filling equipment. Blueberry fruit drops as it is transferred from one equipment to the next on the packing line. The mechanical impacts that occur on blueberry packing line equipment were measured quantitatively with a miniature, instrumented sphere called the blueberry impact recording device (BIRD) at 11 packing houses in the United States in 2013 and 2014. The BIRD sensor recorded impacts at transfer points or wherever there was a vertical drop on the packing line. The potential for impact damage was determined in four cultivars ('Farthing', 'O'Neal', 'Reveille' and 'Star') by dropping fruit from different heights. The measured data revealed that the largest impacts (similar to 230 g) were recorded when the sensor dropped into the hopper above the clamshell filler on eight empty lines. The cumulative peakG data showed strong correlation with overall drop height, indicating that reducing the overall drop height on a packing line could reduce the impact level. When the transfer points were padded with Poron foam sheet, significantly lower levels of impact were recorded by the sensor. The BIRD sensor also recorded lower impacts when it was run with fruit on the packing line. The severity of bruise damage resulting from fruit being dropped was related to the impact data recorded by the BIRD sensor. Using peakG-velocity change plot and the fruit bruising rate, several large impacts sufficient to cause bruising were identified, (e.g., >20% of cut surface area indicating bruise damage in 76% of 'Reveille' fruit). This paper quantitatively measured the mechanical impact on blueberr

关键词： Instrumental neutron activation analysis   Provenance study   Archaeological pottery   k(0) method   La Real   Wari  

摘要： Fragments of archaeological pottery from a rescue excavation at the site of La Real in Arequipa, Peru, were studied by instrumental neutron activation analysis, k (0) method. Analytical data were processed by multivariate statistical techniques, comparing the chemical composition of the studied samples versus the information available in our database on the chemical composition of archaeological pottery from Conchopata (Ayacucho), Cotahuasi (Arequipa), Huaro (Cusco) and Tiwanaku (Bolivia). The results obtained revealed that most of the samples were likely made locally at La Real, while others correspond to the chemical composition of the different groups considered, showing evidence of the presence of foreign pottery in the site and a small group which were not classified.

关键词： HepG2   HEp-2   miRNA-548n   SMAD4   SMAD5   Zinc concentration  

摘要： MicroRNAs affect disease progression and nutrient status. miR-548n increased 57 % in Zn supplemented plasma from adolescent females (ages 9 to 13 years). The purpose of this study was to determine the effects of Zn concentration in cell culture on the expression of miR-548n, SMAD4 and SMAD5 in hepatocyte (HepG2) and lung epithelium (HEp-2) cell lines. Cells were incubated for 48 h in media containing 10 % Chelex 100-treated FBS (0 mu M Zn), or with 15 or 50 mu M Zn, before isolation of total RNA and cDNA. Expression of miR-548n, SMAD4 and SMAD5 was measured by qPCR. The Delta Delta CT method was used to calculate the fold-change, and 15 mu M expression levels were used as reference values. HepG2 miR-548n expression decreased 5-fold, and SMAD4 expression increased 4-fold in the absence of Zn, while HEp-2 miR-548n expression increased 10.5-fold, and SMAD5 expression increased 20-fold in the absence of Zn. HEp-2 miR-548n expression increased 23-fold, while SMAD4 expression decreased twofold, in 50 mu M Zn-treated cells. However, SMAD4 and SMAD5 expression was not correlated. These data indicate that miR-548n expression is in part regulated by Zn in a cell-specific manner. SMAD4 and SMAD5 are genes in the TGF-beta/BMP signaling pathway, and SMAD5 is a putative target for miR-548n;Zn participates in regulating this pathway through controlling SMAD4 and SMAD5 expression. However, SMAD5 expression may be more sensitive to Zn than to miR-548n since SMAD5 expression was not inversely correlated with miR-548n expression.

关键词： behavioral modifications   oil spill   anxiety  

摘要： Mental health issues are a significant concern after technological disasters such as the 2010 Gulf Oil Spill;however, there is limited knowledge about the long-term effects of oil spills. The study was part of a larger research effort to improve understanding of the mental and behavioral health effects of the Deepwater Horizon Gulf Oil Spill. Data were collected immediately following the spill and the same individuals were resampled again after the second anniversary (n = 314). The results show that mental health symptoms of depression, serious mental illness and posttraumatic stress have not statistically decreased, and anxiety symptoms were statistically equivalent to immediate symptoms. Results also showed that the greatest effect on anxiety is related to the extent of disruption to participants' lives, work, family, and social engagement. This study supports lessons learned following the Exxon Valdez spill suggesting that mental health effects are long term and recovery is slow. Elevated symptoms indicate the continued need for mental health services, especially for individuals with high levels of disruption resulting in increased anxiety. Findings also suggest that the longer-term recovery trajectories following the Deepwater Horizon Gulf Oil Spill do not fall within traditional disaster recovery timelines.

关键词： Gulf of Mexico   Ciliate   Microbenthos   Nepheloid   Oil spill  

摘要： Benthic marine protists have been well documented from shallow marine benthic habitats but remain understudied in deeper habitats on continental shelves and slopes, particularly in the Northeastern Gulf of Mexico (NEGOM). This region was affected by a deep water oil well failure (BP-Deepwater Horizon, 2010). The combination of a lack of information on deep sea microbenthic communities and the potential for benthic microbial petroleum mineralization prompted this investigation. Water column and nepheloid layer samples were obtained via Niskin bottles and a multicorer respectively at stations across the NEGOM to: (1) determine whether nepheloid and water column communities are distinct and (2) assess benthic species richness relative to sediment PAH contamination. Phylum specific 185 rRNA gene amplification was used to construct clone libraries of ciliate assemblages. BLAST searches in the NCBI database indicated that a majority (similar to 75%) of the clone sequences corresponded (94-100% similarity) with listed, yet unclassified sequences. Several putative species were common at most site locations and depths. Many known benthic ciliates, such as Uronychia transfuga, Uronychia setigera, and Spirotrachelostyla tani, were common in the nepheloid layer samples and not recovered in water column samples. Ciliated protist species richness increased with PAH levels found in surface sediments, suggesting a positive microbial response to petroleum enrichment of the benthos. The presence of previously unknown microbenthic communites in the nephaloid layer over oceanic clay-silt muds alters our view of microbial processes in the deep sea and merits investigation of the microbial processes and rates of microbial mineralization and biomass production important to global biogeochemistry. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： threaded joint   error in thread pitch   stress-strain state   finite element method   cyclic strength   durability  

摘要： Using the finite element method, the analysis of influence of errors in pitch during the thread production on the behavior of stress distribution in stud-nut joints is performed. The value of maximum local stresses in studs of a threaded joint is shown to substantially depend on errors in thread pitch of a stud and a nut. On the basis of the analyses of stresses and strains under cyclic loading, fatigue curves are plotted for the threaded joints having deviations in thread pitch. It is shown that, with a rational selection of the deviation in pitch, the cyclic strength of threaded joints can be considerably increased. The results of analysis agree satisfactorily with the data of fatigue tests of the M39 x 3 threaded joints.

关键词： mistletoe preparations   equine sarcoid   proliferation   inhibition   Iscucin (R)