757 research outputs found

    Self-assembled arrays of zinc oxide nanoparticles from monolayer films of diblock copolymer micelles

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    A hexagonal array of optically active ZnO nanoparticles was synthesized in situ on the solid substrate by utilizing a single-layered film of diblock copolymer micelles as a nanostructured template.X1135sciescopu

    An advanced procedure for the quantitative risk assessment of offshore installations in explosions

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    Hydrocarbon explosion and fire are typical accidents in the offshore oil and gas industry, sometimes with catastrophic consequences such as casualties, property damage and pollution. Successful engineering and design should meet both functional requirements associated with operability in normal conditions and health, safety, environmental and ergonomics (HSE&E) requirements associated with accidental and extreme conditions. A risk-based approach is best for successful design and engineering to meet HSE&E requirements. This study aimed to develop an advanced procedure for assessing the quantitative risk of offshore installations in explosions. Unlike existing industry practices based on prescriptive rules or qualitative approaches, the proposed procedure uses an entirely probabilistic approach. The procedure starts with probabilistic selection of accident scenarios. As the defining components of risk, both the frequency and consequences associated with selected accident scenarios are computed using the most refined technologies. Probabilistic technology is then applied to establish the relationship between the probability of exceedance and the physical values of the accident. Acceptance risk criteria can be applied to define the nominal values of design and/or level of risk. To validate and demonstrate the applicability of the proposed procedure, an example of its application to topside structures of an FPSO unit subjected to hydrocarbon explosions is detailed. The conclusions and insights obtained are documented

    A simplified inventory approach for estimating carbon in coarse woody debris in high-biomass forests

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    Forests carrying large quantities of live and dead wood are important carbon (C) stores. Here, we investigate how the inventory of coarse woody debris (CWD) and its embedded C (CWD-C) may be designed efficiently at the scale of logs, plots, and the landscape in Tasmanian tall Eucalyptus obliqua forests, which have very high levels of CWD (here 375–1085 m³ ha–1). From a set of 12 sites representing different times since disturbance, a thorough census of dead wood >10 cm in diameter was carried out at five sites using a fixed-plot (50 × 50 m) approach. This showed that 90% of the volume can be captured by recording only CWD logs >40 cm in diameter. Based on this approach and on the known density and C content of five different decay-classes, volume, mass, and CWD-C was determined for all 12 sites. To obtain an accurate estimate of CWD-C at the landscape scale, it was found to be sufficient to allocate entire individual logs to single decay-classes and to use one global value for C content instead of decay-class-specific values. The most decayed logs, which are difficult to measure, could be ignored. However, at the plot level, no relationships were found between CWD mass and either standing or downed CWD or standing-tree biomass, limiting the utility of these proxies for assessing CWD volume

    Strength assessment of stiffened blast walls in offshore installations under explosions

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    Offshore installations are exposed to hydrocarbon explosions and/or fire accidents. Especially, explosions lead to serious damages to human, safety, and environment. To minimise and prevent the damage from explosions, blast walls are generally installed in oil and gas production structures. Typical blast walls are classified into flat, corrugated, and stiffened types. Among them, corrugated blast walls are frequently used for reasons such as construction, cost, and energy absorption. However, it has been known that a corrugated type of blast wall buckles between the web and flange under the explosion loads, and loses its stiffness. It means that the buckling phenomenon of a blast wall is closely related to the structural strength. This study investigates on the structural characteristics of a blast wall under quasi-static and dynamic (explosion) loads with or without a flat-plated stiffener. Finally, it can be concluded that the flat type of stiffeners are located at the buckling region to delay the buckling and improve the strength of blast walls

    Hybrid nanofabrication processes utilizing diblock copolymer nanotemplate prepared by self-assembled monolayer based surface neutralization

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    Nanostructures including nanohole and metal dot arrays were fabricated by hybrid processes combing self-assembled diblock copolymer and conventional semiconductor processes. The interfacial energy between polystyrene-b-polymethylmetacrylate (PS-b-PMMA) diblock copolymer and substrate surface was controlled by employing a self-assembled monolayer (SAM), resulting in a polymer template with well-ordered cylindrical nanohole array. The nanohole sizes were controlled within 10 to 22 nm in diameter using block copolymers with different molecular weights. The PS nanotemplates were fabricated on various substrates, including oxides, nitrides, and poly-Si. Nanohole pattern was transferred by dry etching process, producing inorganic nanohole templates. Also, gold nanodot arrays with diameter smaller than 10 nm were fabricated through lift off process. (c) 2008 American Vacuum Society.open112020sciescopu

    A practical method to determine the dynamic fracture strain for the nonlinear finite element analysis of structural crashworthiness in ship–ship collisions

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    Ship–ship collisions continue to occur regardless of efforts to prevent them. The collisions involve highly nonlinear characteristics associated with structural crashworthiness, including crushing and fracture as well as buckling and plastic collapse. When applying nonlinear finite element analysis (NLFEA) to solve these problems, a reliable critical fracture strain accounting for strain-rate effects due to collision speed must be implemented. This study proposes a practical method to estimate the dynamic fracture strain to be used for the structural crashworthiness analysis associated with the collisions. For this purpose, the strain-rate characteristics in struck ship were investigated by NLFEA, in which the striking vessel was assigned various velocities in the range of practical ship speeds. Based on computations, an empirical formula was developed to calculate the strain rate at a given collision speed, allowing for a practical estimation of the dynamic fracture strain. The formula is validated by a comparison with experiment

    The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana

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    Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific ‘‘avirulent’’ pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NBLRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector

    Sensitivity of markers of DNA stability and DNA repair activity to folate supplementation in healthy volunteers

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    We have previously reported that supplementation with folic acid (1.2 mg day−1 for 12 week) elicited a significant improvement in the folate status of 61 healthy volunteers. We have examined effects of this supplement on markers of genomic stability. Little is known about the effect of folate supplementation on DNA stability in a cohort, which is not folate deficient. Preintervention, there was a significant inverse association between uracil misincorporation in lymphocyte DNA and red cell folate (P<0.05). In contrast, there were no associations between folate status and DNA strand breakage, global DNA methylation or DNA base excision repair (measured as the capacity of the lymphocyte extract to repair 8-oxoGua ex vivo). Folate supplementation elicited a significant reduction in uracil misincorporation (P<0.05), while DNA strand breakage and global DNA methylation remained unchanged. Increasing folate status significantly decreased the base excision repair capacity in those volunteers with the lowest preintervention folate status (P<0.05). Uracil misincorporation was more sensitive to changes in folate status than other measures of DNA stability and therefore could be considered a specific and functional marker of folate status, which may also be relevant to cancer risk in healthy people

    Therapeutic Potential of Combined Herbal Medicine and Electroacupuncture in Mild Cognitive Impairment Through Cytokine Modulation: An Observational Study

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    Jung-Hee Jang,1,&ast; Hyeong Joon Jun,2,&ast; ChaYoung Lee,3,&ast; Eunjin Sohn,4 Ojin Kwon,1 Dong-Hoon Kang,3 Muhammad Umar,2,5 In Chul Jung,3 Soo-Jin Jeong4 1Korean Medicine Science Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea; 2Korean Medicine Data Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea; 3Department of Oriental Neuropsychiatry, College of Korean Medicine, Daejeon University, Daejeon, Republic of Korea; 4Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea; 5Korean Convergence Medical Science, University of Science and Technology, Daejeon, Republic of Korea&ast;These authors contributed equally to this workCorrespondence: Soo-Jin Jeong, Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon, 34054, Republic of Korea, Tel +82-42-868-9651, Email [email protected] In Chul Jung, Department of Oriental Neuropsychiatry, College of Korean Medicine, Daejeon University, Daejeon, 34520, Republic of Korea, Tel +82-42-470-9000, Email [email protected]: We aimed to investigate the efficacy of a combined herbal formula and electroacupuncture (EA) for mild cognitive impairment (MCI), a neurodegenerative disease leading to dementia, and its underlying mechanisms of action.Patients and Methods: This was a prospective open-label observational pilot study at Daejeon Korean Medicine Hospital of Daejeon University in South Korea from March 2022 to March 2023. We included six Korean patients (50% male) aged ≥ 45 years and < 85 years with MCI, a clinical dementia rating score of 0.5, and a Montreal Cognitive Assessment-Korea (MoCA-K) score ≤ 22. The exclusion criterion was impaired cognitive function. Patients received combined therapy, including a herbal formula and EA, for 12– 24 weeks. We prescribed the herbal formulas Gamiguibi-tang, Yukmijihwang-tang, and Banhasasim-tang to the patients for at least 70% of the treatment period, in combination with EA. Moreover, we investigated changes in cognitive and cognition-related symptoms and cytokine expression in the blood following combined traditional medicine therapy. At baseline and after 12 and 24 weeks, we administered the MoCA-K and cognitive-related questionnaires. We analyzed network pharmacology to reflect the herbal formula intervention mechanism comprehensively.Results: The median score [interquartile range] of MoCA-K at baseline was 19.5 [16.0, 22.0], which improved significantly (24.5 [24.0, 26.0], p < 0.01) over 24 weeks following combined therapy. We obtained no significant conclusion regarding cytokine changes due to the small sample size. In network pharmacology, we analyzed the brain, head, heart, peripheral nerves, peripheral nervous system, and pancreas as the enriched organs from the common targets of the three herbal formulas.Conclusion: Combined herbal medicine and EA improved cognitive function in patients with MCI. We assume the underlying mechanism of herbal formulas to be antioxidative and anti-inflammatory changes in cytokine expression. Combined traditional medicine has potential therapeutic application in preventing MCI progression to dementia.Plain Language Summary: This was a single-centered study focusing on the therapeutic effect of combined herbal medicine and electroacupuncture in patients with mild cognitive impairment, including a small number of participants, a relatively long treatment intervention of 12 weeks, and a follow-up assessment of 24 weeks. The intervention was a combination of a herbal formula and electroacupuncture treatment customized for each participant. The blood cytokine analyses of the participants were compared with the network analysis of the predicted target organs and pathways for the herbal formulas administered. Because each participant was not given the exact same intervention, we were unable to identify the specific treatment that produced the predicted effect. The observational study design of the study limited the ability to accurately assess causation between intervention and outcome. However, combined traditional medicine has potential therapeutic application in preventing mild cognitive impairment progression to dementia.Keywords: network pharmacology, inflammation, combination treatment, dementi

    Prevalence and trends of selected urologic conditions for VA healthcare users

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    BACKGROUND: Conducted as part of the Urologic Diseases in America project whose aim was to quantify the burden of urologic diseases on the American public, this study focuses on Veterans Health Administration (VHA) users as a special population to supplement data on overall prevalence rates and trends in the United States. Veterans comprise 25% of the male population 18 years or older and contribute substantially to the overall burden of urologic conditions. The objective of this study is to describe the prevalence rates and trends of urologic cancers and selected benign conditions from 1999 to 2002 for VHA users. METHODS: VHA administrative files for 1999 – 2002 and Medicare claims files for the same years were used to identify those who had a diagnosis of qualifying urologic conditions. RESULTS: Among the conditions evaluated, prostate cancer was listed as a primary diagnosis for 5.4% of VHA users in 2002, followed in decreasing prevalence by erectile dysfunction (2.9%), renal mass (1.5%), interstitial cystitis (1.4%), and prostatitis (1.1%). Age-adjusted rates showed significant increases for renal mass (31%), interstitial cystitis (14%), and erectile dysfunction (8%) between 1999 and 2002. Systematic variations in prevalence rates and trends were observed by age, race/ethnicity, and region. Those in the Western region generally had lower age-adjusted prevalence rates and their increases were also slower than other regions. Addition of Medicare data resulted in large increases (21 to 489%) in prevalence among VHA users, suggesting substantial amount of non-VA urological care provided to VHA users. CONCLUSION: Prevalence rates for many urologic diseases increased between 1999 and 2002, which were not entirely attributable to the aging of veterans. This changing urologic disease burden has substantial implications for access to urologic care and treatment capacity, especially in light of the level of urologic care delivered to veterans by Medicare providers outside the VA. Further study on the factors associated with these increases and how they affect the patterns, cost, and quality of care in veterans is needed
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