Microbial Community Analysis and Effects of Fe(II)/Mn(II) Ratio on Denitrification in the Mixotrophic Biological Reactor

In this study, the denitrification performance of the mixotrophic biological reactor was investigated under varying Fe(II)/Mn(II) molar ratio conditions. Results indicate that the optimal nitrate removal ratio occurred at an Fe(II)/Mn(II) molar ratio of 9:1, pH of 7, with an HRT of 10?h. When the reactor was performing under optimal conditions, the nitrate removal reached 100.00% at a rate of 0.116?mmol·L^?1·h^?1. The proportion of oxidized Fe(II) and Mn(II) reached 99.29% and 21.88%, respectively. High-throughput sequencing results show that Pseudomonas was the dominant species in the mixotrophic biological reactor. Furthermore, the relative abundance of Pseudomonas and denitrification performance was significantly influenced by variation in the Fe(II)/Mn(II) molar ratio.     

HBsAg合成肽段的免疫源性和抗肽血清与天然HBsAg的结合测定

我们将三种乙型肝炎表面抗原的合成肽段在联结载体或不接载体的情况下,分别制备成4种免疫原对兔子进行了免疫。大部分兔子都产生了抗肽抗体。其中抗P_(122-48)(auw)与抗P_(122-148)(adw)都能与天然HBsAg反应,而抗P_(122-148)(adw)的抗HBs活力比文献报道的都高,通过结构分析表明:含有天然蛋白上免疫显性区域的免疫原是合成疫苗的理想选者。     

Deformation Effect on SUVmax Changes in Thoracic Tumors Using 4-D PET/CT Scan

Respiratory motion blurs the standardized uptake value (SUV) and leads to a further signal reduction and changes in the SUV maxima. 4D PET can provide accurate tumor localization as a function of the respiratory phase in PET/CT imaging. We investigated thoracic tumor motion by respiratory 4D CT and assessed its deformation effect on the SUV changes in 4D PET imaging using clinical patient data. Twelve radiation oncology patients with thoracic cancer, including five lung cancer patients and seven esophageal cancer patients, were recruited to the present study. The 4D CT and PET image sets were acquired and reconstructed for 10 respiratory phases across the whole respiratory cycle. The optical flow method was applied to the 4D CT data to calculate the maximum displacements of the tumor motion in respiration. Our results show that increased tumor motion has a significant degree of association with the SUV_max loss for lung cancer. The results also show that the SUV_max loss has a higher correlation with tumors located at lower lobe of lung or at lower regions of esophagus.     

Arabidopsis CSN5B Interacts with VTC1 and Modulates Ascorbic Acid Synthesis

Light regulates ascorbic acid (AsA) synthesis, which increases in the light, presumably reflecting a need for antioxidants to detoxify reactive molecules produced during photosynthesis. Here, we examine this regulation in Arabidopsis thaliana and find that alterations in the protein levels of the AsA biosynthetic enzyme GDP-Man pyrophosphorylase (VTC1) are associated with changes in AsA contents in light and darkness. To find regulatory factors involved in AsA synthesis, we identified VTC1-interacting proteins by yeast two-hybrid screening of a cDNA library from etiolated seedlings. This screen identified the photomorphogenic factor COP9 signalosome subunit 5B (CSN5B), which interacted with the N terminus of VTC1 in yeast and plants. Gel filtration profiling showed that VTC1-CSN5B also associated with the COP9 signalosome complex, and this interaction promotes ubiquitination-dependent VTC1 degradation through the 26S proteasome pathway. Consistent with this, csn5b mutants showed very high AsA levels in both light and darkness. Also, a double mutant of csn5b with the partial loss-of-function mutant vtc1-1 contained AsA levels between those of vtc1-1 and csn5b, showing that CSN5B modulates AsA synthesis by affecting VTC1. In addition, the csn5b mutant showed higher tolerance to salt, indicating that CSN5B regulation of AsA synthesis affects the response to salt stress. Together, our data reveal a regulatory role of CSN5B in light-dark regulation of AsA synthesis.     

Porous Tantalum Coatings Prepared by Vacuum Plasma Spraying Enhance BMSCs Osteogenic Differentiation and Bone Regeneration In Vitro and In Vivo

Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS), which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs) and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.     

Selecting subsets of genotyped experimental populations for phenotyping to maximize genetic diversity

Selective phenotyping is a way of capturing the benefits of large population sizes without the need to carry out large-scale phenotyping and hence is a cost-effective means of capturing information about gene–trait relationships within a population. The diversity within the sample gives an indication of the efficiency of this information capture; less diversity implies greater redundancy of the genetic information. Here, we propose a method to maximize genetic diversity within the selected samples. Our method is applicable to general experimental designs and robust to common problems such as missing data and dominant markers. In particular, we discuss its application to multi-parent advanced generation intercross (MAGIC) populations, where, although thousands of lines may be genotyped as a large population resource, only hundreds may need to be phenotyped for individual studies. Through simulation, we compare our method to simple random sampling and the minimum moment aberration method. While the gain in power over simple random sampling for all tested methods is not large, our method results in a much more diverse sample of genotypes. This diversity can be applied to improve fine mapping resolution once a QTL region has been detected. Further, when applied to two wheat datasets from doubled haploid and MAGIC progeny, our method detects known QTL for small sample sizes where other methods fail.     

The Influences of A Nitrogen Atom Position in Dinucleoside 2-,3-,4-Pyridylphosphonates on Fragmentation Patterns in Electrospray Ionization Multistage Tandem Mass Spectra

2-,3-,4-Pyridylphosphonates and their phosphonothioate congeners were analyzed by electrospray ionization multistage tandem mass spectrometry (ESI-MSⁿ). It was found that the fragmentation pathways of these compounds were not influenced to any detectable extent by the stereochemistry at the phosphorus centers but were sensitive to the position of a nitrogen atom in the pyridine ring of these compounds. Possible mechanisms for fragmentations of the investigated compounds are discussed in detail.

     

广西石灰岩地区蜈蚣蕨居群的遗传多样性研究

采用等位酶分析方法 ,研究了广西石灰岩地区蜈蚣蕨居群的遗传多样性 ,分析了其空间变化趋势。检测了 8个酶系统 ,1 5个酶位点。分析结果表明 :广西石灰岩地区蜈蚣蕨居群遗传多样性程度较高 ,每个位点的等位基因平均数为 1 .6 7,多态位点为 5 7.78% ,平均期望杂合度为 0 .2 4 9。蜈蚣蕨居群的遗传组成在居群间有一定的差异 ,但差异的程度并不与空间距离成正比     

Ability of Clonostachys rosea to Establish and Suppress Sporulation Potential of Botrytis cinerea in Deleafed Stems of Hydroponic Greenhouse Tomatoes

The ability of Clonostachys rosea to establish and persist in deleafed tomato stems and to suppress sporulation potential of Botrytis cinerea was investigated in plots of hydroponic tomatoes in commercial greenhouses. Leaves near lower fruit clusters were removed according to standard practice and deleafed portions of the stems were treated with C. rosea , iprodione or water. Inoculum of B. cinerea was from natural infections. Stem lesions were not produced by the pathogen during the trials. Development of C. rosea and B. cinerea in stems was estimated indirectly by quantifying sporulation on excised stem tissues that were incubated on an agar medium containing paraquat. Incidence and area of sporulation of C. rosea on tissue pieces were high (76-99%) and moderately high (33-79%), respectively, when stems were treated with the agent at 0, 6, 24 or 48 h after deleafing and sampled 11 to 75 days later. In various instances, the agent also sporulated on tissues from water controls and iprodione treatments, apparently after interplot transmission. In most instances, incidence and area of sporulation of B. cinerea on tissue pieces were high (83-100%) and moderate to high (35-76%), respectively, in the water controls, but moderate (31-44%) and moderate to low (5-34%), respectively, for stems treated with C. rosea at 0 to 48 h after deleafing and sampled after 11-75 days. Without exception, C. rosea suppressed B. cinerea as or more effectively than iprodione. Correlations between inoculum density of C. rosea (0-10 6 conidia mL -1 ) and sporulation potential of B. cinerea in deleafed stems were strongly negative in each of three tests ( r = -0.95 to -0.99). Conidial suspensions and a talc formulation of C. rosea were of similar effectiveness against B. cinerea . We conclude that C. rosea persisted and suppressed sporulation potential of B. cinerea in deleafed tomato stems for at least 11 weeks after application.