115 research outputs found
Approaches to maintaining provenance throughout the additive manufacturing process
No full textThe development of 3D printers has resulted in significant Intellectual Property Right issues. This work presents a model for signing printable 3D objects. The paper initially reviews the security principles of signing of objects in both digital or physical form, and the metrics for assessing signatures. 3D designs are not just a file, but actual physical objects and should be treated identically, to digital documents that have associated intellectual property rights and copyright protection. In this paper we propose a signing methodology intended to resolve issues with the adaptation of rapid prototyping and 3D printing by users both in engineering and the humanities. The proposed digital signing methodology is based on physical signing principles that follow archival principles to maintain accurate records. The new model allows the transition of provenance between digital and physical form
Arbuscular mycorrhizal fungi (AMF) species and abundance exhibit different effects on saline-alkaline tolerance in Leymus chinensis
No full textArbuscular mycorrhizal fungi (AMF) was considered as a biotechnological tool for plant stress tolerance improvement and degraded ecosystem restoration. However, the variations in the effects of AMF species and abundance on plant performance under stress condition have to be still investigated. The study was conducted to evaluate the mechanisms of five AMF species, single or mixture, on Leymus chinensis stress tolerance along a saline-alkaline gradient. The results showed that AMF enhanced plant stress tolerance by promoting plant growth, enhancing nutrient absorption, maintaining ion balance, and improving photosynthetic efficiency. Funneliformis mosseae, Rhizophagus intraradices and the mixture treatments had more beneficial effects than Diversispora versiformis and Acaulospora scrobiculata inoculations. Plant grown under high stress level exhibited more benefits from AMF symbiosis. Our study suggests that not only presence of AMF, but also the species and abundance should be considered to reveal the exact effects of AMF on plant saline-alkaline tolerance and degraded grassland restoration. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Deep tillage reduces the dependence of tobacco on AMF and promotes the growth of tabacco(Nicotiana tabacum L.) in dryland
No full textThe traditional shallow tillage method makes the soil quality declining, and affects the efficiency of agricultural production. Taking the conventional rotary tillage(12 cm) as the control, Yunyan 87 as the test variety, and the soil type of the test site is paddy soil, we studied the effects of deep tillage(Subsoiling 30 cm) on soil nutrients, arbuscular mycorrhizal fungi (AMF) and tobacco（Nicotiana tabacum L.）growth. The results showed that deep tillage increased the contents of organic carbon, available phosphorus(AP) and available potassium(AK) in 20 ~ 40 cm soil layer. The community of AMF was changed by deep tillage. Glomus, the dominant genus in both group, increased significantly in the soil after deep tillage. The colonization rate of AMF was lower than that of conventional rotary tillage. Deep tillage was beneficial to the growth of tobacco in the middle and late stages. Root growth and nutrient content of tobacco increased. Deep tillage significantly improved the output value of tobacco. It can be seen that deep tillage is conducive to improving soil fertility, promoting the vigorous growth of root, reducing the dependence of tobacco on AMF, and promoting the high quality and yield of tobacco in drylands of Hunan.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
On-Demand Magnetically-Activated Drug Delivery from Additively Manufactured Porous Bone Implants to Tackle Antibiotic-Resistant Infections
No full textThis study proposes a new concept for an on-demand drug releasing device intended for integration into additively manufactured (i.e., 3D printed) orthopedic implants. The system comprises a surface with conduits connected to a subsurface reservoir used for storage and on-demand release of antimicrobial agents, covered with a cap that prevents the antibacterial agents from being released until alternating magnetic field (AMF) raises the temperature of the cap, thus, releasing the stored drug. To demonstrate this concept, Ti6Al4V specimens are directly 3D printed using selective laser melting and their surface, reservoirs, and drug releasing properties are characterized. A new synthetic antimicrobial peptide, SAAP-148, is thereafter tested for its cytotoxic, osteogenic, and immunomodulatory effects at concentrations relevant for its minimal bactericidal concentration (MBC) and is compared with its natural analogue, LL-37. The results showed that AMF successfully activated the release from the 3D printed loaded samples. Both peptides demonstrated to be non-cytotoxic within the MBC levels for macrophages and preosteoblasts and did not influence their osteoimmunomodulatory behavior. The findings of this study indicate that the proposed concept is technically feasible and has the potential to be used for the development of bone implants with on-demand delivery systems to fight IAI without systemic or continuous local release of antibiotics.Biomaterials & Tissue Biomechanic
Hypoxia enhances the expression of autocrine motility factor and the motility of human pancreatic cancer cells
No full textThe incidence of distant metastases is higher in the tumors with low oxygen pressure than in those with high oxygen pressure. It is well known that hypoxia induces the transcription of various genes involved in angiogenesis and anaerobic metabolism necessary for the growth of tumor cells in vivo, suggesting that hypoxia may also induce the transcription of metastasis-associated genes. We sought to identify the metastasis-associated genes differentially expressed in tumor cells under hypoxic conditions with the use of a DNA microarray system. We found that hypoxia enhanced the expression of autocrine motility factor (AMF) mRNA in various cancer cells and also enhanced the random motility of pancreatic cancer cells. AMF inhibitors abrogated the increase of motility under hypoxic conditions. In order to explore the roles of hypoxia-inducible factor-1α (HIF-1α), we established HIF-1α-transfectants and dominant negative HIF-1α-transfectants. Transfection with HIF-1α and dominant-negative HIF-1α enhanced and suppressed the expression of AMF/PHI/NL mRNA and the random motility, respectively. These results suggest that hypoxia may promote the metastatic potential of cancer cells through the enhanced AMF/PHI/NL mRNA expression and that the disruption of the HIF-1 pathway may be an effective treatment for metastasis
Combination of arbuscular mycorrhizal fungi and phosphate solubilizing bacteria on growth and production of <em>Helianthus tuberosus</em> under field condition
No full text\ua9 2021, The Author(s). In this work, the effects of co-inoculation between an arbuscular mycorrhizal fungus (AMF) and a phosphate solubilizing bacteria (PSB) to promote the growth and production of sunchoke under field condition were investigated during 2016 and 2017. Four treatments were set up as follows: plants without inoculation, with AMF inoculation, with PSB inoculation and with co-inoculation of PSB and AMF. The results showed the presence of PSB and AMF colonization at the harvest stage in both years. This suggested the survival of PSB and successful AMF colonization throughout the experiments. According to correlation analysis, PSB positively affected AMF spore density and colonization rate. Also, both AMF and PSB positively correlated with growth and production of sunchoke. Co-inoculation could enhance various plant parameters. However, better results in 2016 were found in co-inoculation treatment, while AMF inoculation performed the best in 2017. All of these results suggested that our AMF and PSB could effectively promote growth and production of sunchoke under field conditions. Such effects were varied due to different environmental conditions each year. Note that this is the first study showing successful co-inoculation of AMF and PSB for promoting growth and yield of sunchoke in the real cultivation fields
Arbuscular mycorrhizal fungi diversity associated with two halophytes Lycium barbarum L. and Elaeagnus angustifolia L. in Ningxia, China
No full textThe Arbuscular mycorrhizal fungi (AMF) community in saline soils of Ningxia, China, was rarely reported. Soils in the rhizosphere of two important food plants, Lycium barbarum L. (Goji) and Elaeagnus angustifolia L. (Oleaster), were sampled from Ningxia (Goji from Huinong, HNGQ; Goji from Yinchuan, YCGQ; Oleaster from Yinchuan, YCSZ) to investigate the AMF community. Thirty-three AMF species from 11 genera were identified in total. The dominant family and genera were Glomeraceae, Acaulospora and Glomus, respectively. Septoglomus constrictum was the most abundant species. The AMF community composition of Goji was different from that of Oleaster (R=0.26, p<0.05), while the AMF community from Huinong differed from Yinchuan (R=1.0, p=0.01). These findings suggest a high AMF diversity in Ningxia saline soils and the effect of host plant identity on AMF community composition. Furthermore, the AMF diversity index positively correlated with available potassium (AK), available phosphorus (AP), available nitrogen (AN) and organic matter (OM), but negatively correlated with electric conductivity (EC). This result demonstrated that a high level of salinity might reduce soil fertility and AMF diversity. The saline area with high diversity of the AMF community in Ningxia is promising for screening AMF isolates for utilization in crop production
Strong host-specific selection and over-dominance characterize arbuscular mycorrhizal fungal root colonizers of coastal sand dune plants of the Mediterranean region
No full textSand dunes of the Mediterranean region constitute drought-stressed, low-fertility ecosystems. Arbuscular mycorrhizal fungi (AMF) are regarded as key components of their biota, that contribute to plant host adaptation and fitness. However, AMF community assembly rules in the roots of the psammophilous plants of coastal sand dunes have not been investigated. We studied the root colonizing AMF communities of four characteristic native plants of eastern Mediterranean coastal foredunes, in nine locations in Greece. Host-specificity (plant identity) was the major driver of AMF community assembly in the plant roots, while geographical distance between locations was not related to differences in the AMF communities. Additionally, colonizer AMF communities were characterized by over-dominance of a single operational taxanomic unit (OTUs), which was remarkably host-specific among locations. Wider dissimilarity in AMF communities was observed in small and disturbed (SD) sites compared to large and undisturbed (LU) sites, a trait that may be attributed to relaxed environmental filtering and facilitated AMF dispersal/immigration in SD sites from surrounding habitats. Overall, our results indicate that the assembly of root-colonizing AMF communities in the eastern Mediterranean sand dunes is characterized by strong biotic filtering (host identity), suggesting that co-adaptation processes may be more pronounced than previously proposed, under extreme environmental conditions. © 2021 The Author(s) 2021. Published by Oxford University Press on behalf of FEMS. All rights reserved. For permissions, please e-mail: [email protected]
New fungal primers reveal the diversity of Mucoromycotinian arbuscular mycorrhizal fungi and their response to nitrogen application
No full text\ua9 The Author(s) 2024.Background: Arbuscular mycorrhizas (AM) are the most widespread terrestrial symbiosis and are both a key determinant of plant health and a major contributor to ecosystem processes through their role in biogeochemical cycling. Until recently, it was assumed that the fungi which form AM comprise the subphylum Glomeromycotina (G-AMF), and our understanding of the diversity and ecosystem roles of AM is based almost exclusively on this group. However recent evidence shows that fungi which form the distinctive \u27fine root endophyte’ (FRE) AM morphotype are members of the subphylum Mucoromycotina (M-AMF), so that AM symbioses are actually formed by two distinct groups of fungi. Results: We investigated the influence of nitrogen (N) addition and wheat variety on the assembly of AM communities under field conditions. Visual assessment of roots showed co-occurrence of G-AMF and M-AMF, providing an opportunity to compare the responses of these two groups. Existing ‘AM’ 18S rRNA primers which co-amplify G-AMF and M-AMF were modified to reduce bias against Mucoromycotina, and compared against a new ‘FRE’ primer set which selectively amplifies Mucoromycotina. Using the AM-primers, no significant effect of either N-addition or wheat variety on G-AMF or M-AMF diversity or community composition was detected. In contrast, using the FRE-primers, N-addition was shown to reduce M-AMF diversity and altered community composition. The ASV which responded to N-addition were closely related, demonstrating a clear phylogenetic signal which was identified only by the new FRE-primers. The most abundant Mucoromycotina sequences we detected belonged to the same Endogonales clades as dominant sequences associated with FRE morphology in Australia, indicating that closely related M-AMF may be globally distributed. Conclusions: The results demonstrate the need to consider both G-AMF and M-AMF when investigating AM communities, and highlight the importance of primer choice when investigating AMF community dynamics
Effect of three-year amendment measures on coastal saline-alkali soil conditions during the growing season
No full textSeawater intrusion and fluctuations in the water table in coastal areas lead to seasonal variations in soil salinity and pH, which greatly limit the development of coastal protection forests. In a three-year field study, the impact of five soil amendment measures were evaluated on soil conditions in coastal areas. Amendments included biochar, biochar with arbuscular mycorrhizal fungi (AMF), straw with AMF, straw alone, and AMF alone, compared to a control (CK) with no additive. Results indicated that combinations of straw, biochar, and AMF reduced soil pH across various layers and seasons, with electrical conductivity mainly decreasing in spring. During the summer, at the 0-20 cm soil depth, microbial biomass carbon notably increased due to these mixtures. Additionally, AMF alone and biochar with AMF significantly improved enzyme activities in the 0-40 cm layer in spring, while in fall, AMF alone notably increased nutrient availability in the same layer. Linear regression analysis revealed a negative correlation between electrical conductivity, microbial biomass carbon, enzyme activity, and nutrient availability with pH. The biochar–AMF mixture emerged as the most effective soil amendment, suggesting that using it in conjunction with seasonal management could optimize soil health and promote silviculture in coastal regions.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
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