Seawater carbonate chemistry and carbon and nitrogen fixation in the hermatypic coral Galaxea fascicularis

The supply of metabolites from symbionts to scleractinian corals is crucial to coral health. Members of the Symbiodiniaceae can enhance coral calcification by providing photosynthetically fixed carbon (PFC) and energy, whereas dinitrogen (N2)-fixing bacteria can provide additional nutrients such as diazotrophically-derived nitrogen (DDN) that sustain coral productivity especially when alternative external nitrogen sources are scarce. How these mutualistic associations benefit corals in the future acidifying ocean is not well understood. In this study, we investigated the possible effects of ocean acidification (OA; pHs 7.7 and 7.4 vs. 8.1) on calcification in the hermatypic coral Galaxea fascicularis with respect to PFC and DDN assimilation. Our measurements based on isotopic tracing showed no significant differences in the assimilation of PFC among different pH treatments, but the assimilation of DDN decreased significantly after 28 days of stress at pH 7.4. The decreased DDN assimilation suggests a nitrogenous nutrient deficiency in the coral holotiont, potentially leading to reduced coral calcification and resilience to bleaching and other stressful events. This contrasting impact of OA on carbon and N flux demonstrates the flexibility of G. fascicularis in coping with OA, apparently by sustaining a largely undamaged photosystem at the expense of N2 fixation machinery, which competes with coral calcification for energy from photosynthesis. These findings shed new light on the critically important but more vulnerable N cycling in hospite, and on the trade-off between coral hosts and symbionts in response to future climate change

Amplification and up-regulation of microRNA-30b in oral squamous cell cancers

Objectives: MicroRNAs (miRNAs) are negative regulators of protein coding genes which are frequently deregulated in mammary cancers. Over-expression of microRNA-30b (hsa-miR-30b) is implicated in tumour invasion and immunosuppression during metastasis. The chromosome locus of MIR3OB gene, 8q24, is frequently amplified in oral squamous cell cancers (OSCCs). In the present study, we aimed to investigate the copy number variations as well as expression levels of MIR3OB gene in OSCCs and analyse their correlation with tumour stage. Design: Quantitative real-time PCR was performed to examine the copy number of MIR-30B gene as well as hsa-miR-30b expression in 107 OSCC samples with matched adjacent normal tissues. Proportional odds regression and two-way repeated measurement ANOVA were used to analyse the association between copy number variations (CNVs) and hsa-miR-30b expression. Results: Copy number gains of MIR-30B gene were detected in a relatively large percentage of the OSCC samples (27.1%, 29 out of 107) and were correlated with tumour stages (p < 0.001). MIR3OB gene amplification also showed a close correlation with hsa-miR-30b over-expression in OSCCs (p < 0.001). On the other hand, enhanced miR-30b expression was also detected in a group of OSCC samples with unaltered copy number of MIR3OB gene. Conclusions: Copy number increase of MIR3OB is frequent in advanced OSCC and is correlated with hsa-miR-30b over-expression. Sporadic OSCCs can exhibit different mechanisms of MIR3OB regulation. (C) 2012 Elsevier Ltd. All rights reserved

Spatiotemporal Dynamics of Scrub Typhus in Jiangxi Province, China, from 2006 to 2018

Background: Scrub typhus (ST) has become a significant potential threat to public health in Jiangxi. Further investigation is essential for the control and management of the spatiotemporal patterns of the disease. Methods: Time-series analyses, spatial distribution analyses, spatial autocorrelation analysis, and space-time scan statistics were performed to detect spatiotemporal dynamics distribution of the incidence of ST. Results: From 2006 to 2018, a total of 5508 ST cases occurred in Jiangxi, covering 79 counties. The number of ST cases increased continuously from 2006 to 2018, and there was obvious seasonality during the variation process in each year, with a primary peak in autumn (September to October) and a smaller peak in summer (June to August). From 2007 to 2018, the spatial distribution of the ST epidemic was significant heterogeneity, and Nanfeng, Huichang, Xunwu, Anyuan, Longnan, and Xinfeng were hotspots. Seven spatiotemporal clusters were observed using Kulldorff’s space-time scan statistic, and the most likely cluster only included one county, Nanfeng county. The high-risk areas of the disease were in the mountainous, hilly region of Wuyi and the southern mountainous region of Jiangxi. Conclusions: Targeted interventions should be executed in high-risk regions for the precise prevention and control of ST

Feasibility Study on Online Diagnosis of Aging and Deterioration of Medium Voltage (MV) Three-Core Cable Based on Impedance Spectroscopy

In order to explore the feasibility of impedance spectroscopy in the application of online diagnosis of aging and deterioration of medium voltage (MV) three-core cables, based on the theory of transmission line equation, an aging and deterioration model of the MV three-core cable has been established. The impedance spectroscopy of the cable head-end under healthy and different aging and degradation states has been simulated and analyzed. Further, the effects the extent of aging, local deterioration size and position, line length, load rate and other factors on the impedance spectroscopy have been studied. According to the influence of the various factors on the impedance spectroscopy, a set of aging and deterioration diagnosis procedures and methods are proposed. The simulation results indicate that the state of the cable can be divided into 4 categories of &#x201C;healthy,&#x201D; &#x201C;overall aging,&#x201D; &#x201C;large-size deterioration&#x201D; and &#x201C;small-size deterioration.&#x201D; The impedance spectroscopies of different states have certain characteristics. These characteristics can be determined by specific criterion indicators such as the monotonous decrease of the value of the resonance peaks and the phase amplitudes, the value of the resonance peaks, and the eigen propagation frequency, etc. Therefore, impedance spectroscopy has broad application prospects for online diagnosis of aging and deterioration of MV three-core cable

Characterization and Bioactivity Evaluation of (Polyetheretherketone/Polyglycolicacid)-Hydroyapatite Scaffolds for Tissue Regeneration

Bioactivity and biocompatibility are crucial for tissue engineering scaffolds. In this study, hydroxyapatite (HAP) was incorporated into polyetheretherketone/polyglycolicacid (PEEK/PGA) hybrid to improve its biological properties, and the composite scaffolds were developed via selective laser sintering (SLS). The effects of HAP on physical and chemical properties of the composite scaffolds were investigated. The results demonstrated that HAP particles were distributed evenly in PEEK/PGA matrix when its content was no more than 10 wt %. Furthermore, the apatite-forming ability became better with increasing HAP content after immersing in simulated body fluid (SBF). Meanwhile, the composite scaffolds presented a greater degree of cell attachment and proliferation than PEEK/PGA scaffolds. These results highlighted the potential of (PEEK/PGA)-HAP scaffolds for tissue regeneration

Preparation and characterization of Ce-Zr mixed oxide with high surface area(高比表面积Ce-Zr-O复合氧化物的制备与表征)

以Ce(NO3)3·6H2O和Zr(NO3)4·5H2O为原料,采用共沉淀法,合成了高比表面积的Ce-Zr-O复合氧化物.实验结果表明表面活性剂的添加量, 溶液的pH值及陈化时间等对比表面积的增加影响较大.当表面活性剂的添加量为70%, pH值为9.5, 陈化时间为120 h, 923 K焙烧2 h后, 样品的比表面积达到279.69 m2/g.FT-IR分析显示, 样品经923 K焙烧后,Ce-Zr-O上残留的活性剂已基本除去. TG-DTA分析表明353 K干燥后的样品在TG曲线上有两个明显的失重过程,与DTA曲线相对应有两个吸热峰, 第一个表示吸附水和丙酮的脱去过程,温度在393 K,失重率为7.43%;第二个吸热峰在787 K,可能是表面活性剂的分解峰. 氮气的吸-脱附实验揭示, 该吸-脱附等温线属于Ⅳ型等温线,是中孔多孔物质的吸附类型.另外, 样品经973 K焙烧,比表面为230.69 m2/g;1073 K焙烧后,比表面为120.55 m2/g;经1173 K焙烧,仍有53.53 m2/g