369 research outputs found

    MicroRNA and messenger RNA profiling reveals new biomarkers and mechanisms for RDX induced neurotoxicity

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    Background RDX is a well-known pollutant to induce neurotoxicity. MicroRNAs (miRNA) and messenger RNA (mRNA) profiles are useful tools for toxicogenomics studies. It is worthy to integrate MiRNA and mRNA expression data to understand RDX-induced neurotoxicity. Results Rats were treated with or without RDX for 48 h. Both miRNA and mRNA profiles were conducted using brain tissues. Nine miRNAs were significantly regulated by RDX. Of these, 6 and 3 miRNAs were up- and down-regulated respectively. The putative target genes of RDX-regulated miRNAs were highly nervous system function genes and pathways enriched. Fifteen differentially genes altered by RDX from mRNA profiles were the putative targets of regulated miRNAs. The induction of miR-71, miR-27ab, miR-98, and miR-135a expression by RDX, could reduce the expression of the genes POLE4, C5ORF13, SULF1 and ROCK2, and eventually induce neurotoxicity. Over-expression of miR-27ab, or reduction of the expression of unknown miRNAs by RDX, could up-regulate HMGCR expression and contribute to neurotoxicity. RDX regulated immune and inflammation response miRNAs and genes could contribute to RDX- induced neurotoxicity and other toxicities as well as animal defending reaction response to RDX exposure. Conclusions Our results demonstrate that integrating miRNA and mRNA profiles is valuable to indentify novel biomarkers and molecular mechanisms for RDX-induced neurological disorder and neurotoxicity.published_or_final_versio

    Self-Cleaning Glass of Photocatalytic Anatase TiO2@Carbon Nanotubes Thin Film by Polymer-Assisted Approach

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    Due to the good photocatalytic activity, the TiO2@CNTs thin film is highly desirable to apply to the self-cleaning glass for green intelligent building. Here, the TiO2@CNTs thin film has been successfully achieved by polymer-assisted approach of an aqueous chemical solution method. The polymer, polyethylenimine, aims to combine the Ti4+ with CNTs for film formation of TiO2@CNTs. The resultant thin film was uniform, highly transparent, and super-hydrophilic. Owing to fast electron transport and effectively hindering electron-hole recombination, the TiO2@CNTs thin film has nearly twofold photocatalytic performance than pure TiO2. The TiO2@CNTs thin films show a good application for self-cleaning glasses

    The use of mesenchymal stem cells for cartilage repair and regeneration: a systematic review.

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    BACKGROUND: The management of articular cartilage defects presents many clinical challenges due to its avascular, aneural and alymphatic nature. Bone marrow stimulation techniques, such as microfracture, are the most frequently used method in clinical practice however the resulting mixed fibrocartilage tissue which is inferior to native hyaline cartilage. Other methods have shown promise but are far from perfect. There is an unmet need and growing interest in regenerative medicine and tissue engineering to improve the outcome for patients requiring cartilage repair. Many published reviews on cartilage repair only list human clinical trials, underestimating the wealth of basic sciences and animal studies that are precursors to future research. We therefore set out to perform a systematic review of the literature to assess the translation of stem cell therapy to explore what research had been carried out at each of the stages of translation from bench-top (in vitro), animal (pre-clinical) and human studies (clinical) and assemble an evidence-based cascade for the responsible introduction of stem cell therapy for cartilage defects. This review was conducted in accordance to PRISMA guidelines using CINHAL, MEDLINE, EMBASE, Scopus and Web of Knowledge databases from 1st January 1900 to 30th June 2015. In total, there were 2880 studies identified of which 252 studies were included for analysis (100 articles for in vitro studies, 111 studies for animal studies; and 31 studies for human studies). There was a huge variance in cell source in pre-clinical studies both of terms of animal used, location of harvest (fat, marrow, blood or synovium) and allogeneicity. The use of scaffolds, growth factors, number of cell passages and number of cells used was hugely heterogeneous. SHORT CONCLUSIONS: This review offers a comprehensive assessment of the evidence behind the translation of basic science to the clinical practice of cartilage repair. It has revealed a lack of connectivity between the in vitro, pre-clinical and human data and a patchwork quilt of synergistic evidence. Drivers for progress in this space are largely driven by patient demand, surgeon inquisition and a regulatory framework that is learning at the same pace as new developments take place

    Maternal care in rural China: a case study from Anhui province

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    <p>Abstract</p> <p>Background</p> <p>Studies on prenatal care in China have focused on the timing and frequency of prenatal care and relatively little information can be found on how maternal care has been organized and funded or on the actual content of the visits, especially in the less developed rural areas. This study explored maternal care in a rural county from Anhui province in terms of care organization, provision and utilization.</p> <p>Methods</p> <p>A total of 699 mothers of infants under one year of age were interviewed with structured questionnaires; the county health bureau officials and managers of township hospitals (n = 10) and county level hospitals (n = 2) were interviewed; the process of the maternal care services was observed by the researchers. In addition, statistics from the local government were used.</p> <p>Results</p> <p>The county level hospitals were well staffed and equipped and served as a referral centre for women with a high-risk pregnancy. Township hospitals had, on average, 1.7 midwives serving an average population of 15,000 people. Only 10–20% of the current costs in county level hospitals and township hospitals were funded by the local government, and women paid for delivery care. There was no systematic organized prenatal care and referrals were not mandatory. About half of the women had their first prenatal visit before the 13th gestational week, 36% had fewer than 5 prenatal visits, and about 9% had no prenatal visits. A major reason for not having prenatal care visits was that women considered it unnecessary. Most women (87%) gave birth in public health facilities, and the rest in a private clinic or at home. A total of 8% of births were delivered by caesarean section. Very few women had any postnatal visits. About half of the women received the recommended number of prenatal blood pressure and haemoglobin measurements.</p> <p>Conclusion</p> <p>Delivery care was better provided than both prenatal and postnatal care in the study area. Reliance on user fees gave the hospitals an incentive to put more emphasis on revenue generating activities such as delivery care instead of prenatal and postnatal care.</p

    Predictive Markers of Honey Bee Colony Collapse

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    Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies

    Genetic variation of male reproductive success in a laboratory population of Anopheles gambiae

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    <p>Abstract</p> <p>Background</p> <p>For Anopheline mosquitoes, the vectors of human malaria, genetic variation in male reproductive success can have important consequences for any control strategy based on the release of transgenic or sterile males.</p> <p>Methods</p> <p>A quantitative genetics approach was used to test whether there was a genetic component to variation in male reproductive success in a laboratory population of <it>Anopheles gambiae</it>. Swarms of full sibling brothers were mated with a fixed number of females and their reproductive success was measured as (1) proportion of ovipositing females, (2) proportion of ovipositing females that produced larvae, (3) proportion of females that produced larvae, (4) number of eggs laid per female, (5) number of larvae per ovipositing female and (6) number of larvae per female.</p> <p>Results</p> <p>The proportion of ovipositing females (trait 1) and the proportion of ovipositing females that produced larvae (trait 2) differed among full sib families, suggesting a genetic basis of mating success. In contrast, the other measures of male reproductive success showed little variation due to the full sib families, as their variation are probably mostly due to differences among females. While age at emergence and wing length of the males were also heritable, they were not associated with reproductive success. Larger females produced more eggs, but males did not prefer such partners.</p> <p>Conclusion</p> <p>The first study to quantify genetic variation for male reproductive success in <it>A. gambiae </it>found that while the initial stages of male reproduction (i.e. the proportion of ovipositing females and the proportion of ovipositing females that produced larvae) had a genetic basis, the overall reproductive success (i.e. the mean number of larvae per female) did not.</p

    Partial oxidation of methane to syngas over Rh/SiO2 catalyst

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    Partial oxidation of methane (POM) over Rh/SiO2 Catalyst was investigated by using several techniques, such as TPD, TPR, TPSR and trapping agent, combined with MS. At the beginning of POM reaction, only gaseous CO2 can be detected over the catalyst. With the increase in space velocity, the conversion of CH4 and the selectivity for CO and H-2 increase, while the selectivity for CO2 decreases. During the pulse reaction with CH4 as reactant, over the catalyst prereduced at 700 degreesC, CO and H-2 can be detected as main products with trace C2H6 and C2H4. When the catalyst is exposed to CH4-He, there are two kinds of carbonaceous species formed, and they are designated CHalpha and CHbeta, as identified by their hydrogenation temperature of 210 similar to 260 degreesC and 450 similar to 800 degreesC, respectively. The CHalpha is assigned to H-rich form and the CHbeta is assigned to H-deficient form. When the catalyst is exposed to CH4-O-2-He, the carbonaceous species are mainly CHalpha with trace CHbeta. The two kinds of carbonaceous species may play different roles in POM reaction. The CHbeta accumulated during CH4 activation is the possible cause for catalyst deactivation, and the CHalpha may be responsible for CO formation. The CHx may be the intermediate of POM reaction. In the trapping reaction, a series of ions with M-r/z = 2 similar to 46 have been detected at 300 similar to 600 degreesC. The CHxO (x = 1 similar to 3) may be the O-containing intermediate of POM reaction. Based on the above results, the POM mechanism has been proposed. Over the reduced catalyst, CH4 is firstly dissociated, forming the surface species CHx. By reacting with the active species OH-, the CHalpha is oxidized to O-containing intermediate, CHxO, which can be dehydrogenated to give the adsorbed and gaseous CO

    Regulatory Feedback Loop of Two phz Gene Clusters through 5′-Untranslated Regions in Pseudomonas sp. M18

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    BACKGROUND: Phenazines are important compounds produced by pseudomonads and other bacteria. Two phz gene clusters called phzA1-G1 and phzA2-G2, respectively, were found in the genome of Pseudomonas sp. M18, an effective biocontrol agent, which is highly homologous to the opportunistic human pathogen P. aeruginosa PAO1, however little is known about the correlation between the expressions of two phz gene clusters. METHODOLOGY/PRINCIPAL FINDINGS: Two chromosomal insertion inactivated mutants for the two gene clusters were constructed respectively and the correlation between the expressions of two phz gene clusters was investigated in strain M18. Phenazine-1-carboxylic acid (PCA) molecules produced from phzA2-G2 gene cluster are able to auto-regulate expression itself and activate the expression of phzA1-G1 gene cluster in a circulated amplification pattern. However, the post-transcriptional expression of phzA1-G1 transcript was blocked principally through 5'-untranslated region (UTR). In contrast, the phzA2-G2 gene cluster was transcribed to a lesser extent and translated efficiently and was negatively regulated by the GacA signal transduction pathway, mainly at a post-transcriptional level. CONCLUSIONS/SIGNIFICANCE: A single molecule, PCA, produced in different quantities by the two phz gene clusters acted as the functional mediator and the two phz gene clusters developed a specific regulatory mechanism which acts through 5'-UTR to transfer a single, but complex bacterial signaling event in Pseudomonas sp. strain M18

    Effect of surface oxygen concentration on activation of methane over supported metal catalysts

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    Activation of methane over supported metal catalysts was investigated using MS-pulse technique on-line. Oxygen-free CH4 pulsing reactions were carried out over both Rh/SiO2 and Ru/SiO2 at 700 degreesC. Large amounts of CO and CO2 were observed at the first pulse of CH4 over oxidized Rh(O)/SiO2 catalyst. However, no CO2 formation was observed at the second pulse and thereafter. Similar to the response of Rh(O) /SiO2 catalyst, the intensity of CO and CO2 was strong at the first pulse over reduced Rh/SiO2 catalyst, and CO2 appeared also only at the first pulse over Rh/SiO2 catalyst. No CO2 was detected at the second pulse and thereafter. CH4 pulsing over Ru(O)/SiO2 catalyst also produced CO and CO2. CO and CO2 were detected from the first pulse I and their intensity was much stronger than that of CO and CO2 produced over Rh/SiO2 catalyst. However, unlike Rh/SiO2 catalyst, CO2 was formed at every pulse over Ru(O)/SiO2 catalyst. Pulsing CH4 over Ru/SiO2 catalyst also produced both CO and CO2 at every pulse. This difference between Rh and Ru catalysts may be due to the difference in the bond strength of Ru-O (528.4 kJ/mol) and Rh-O (405.1 kJ/mol) and in their relative oxygen affinities, Ru-0 can be more easily oxidized by O-2 than Rh-0 owing to the greater oxygen affinity of Ru. Surface oxygen should play an important role in the activation of methane and the product distribution
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