Synthesis of magnetic cobalt ferrite nanoparticles with controlled morphology, monodispersity and composition: the influence of solvent, surfactant, reductant and synthetic conditions

In our present work, magnetic cobalt ferrite (CoFe2O4) nanoparticles have been successfully synthesised by thermal decomposition of Fe(III) and Co(II) acetylacetonate compounds in organic solvents in the presence of oleic acid (OA)/ oleylamine (OLA) as surfactants and 1,2-hexadecanediol (HDD) or octadecanol (OCD-ol) as an accelerating agent. As a result, CoFe2O4 nanoparticles of different shapes were tightly controlled in size (range of 4–30 nm) and monodispersity (standard deviation only at ca. 5%). Experimental parameters, such as reaction time, temperature, surfactant concentration, solvent, precursor ratio, and accelerating agent, in particular, the role of HDD, OCD-ol, and OA/OLA have been intensively investigated in detail to discover the best conditions for the synthesis of the above magnetic nanoparticles. The obtained nanoparticles have been successfully applied for producing oriented carbon nanotubes (CNTs), and they have potential to be used in biomedical applications

What prize is right? How to learn the optimal structure for crowdsourcing contests

In crowdsourcing, one effective method for encouraging par-ticipants to perform tasks is to run contests where participants compete against each other for rewards. However, there are numerous ways to implement such contests in specific projects. They could vary in their structure (e.g., performance evaluation and the number of prizes) and parameters (e.g., the maximum number of participants and the amount of prize money). Additionally, with a given budget and a time limit, choosing incentives (i.e., contest structures with specific parameter values) that maximise the overall utility is not trivial, as their respective effectiveness in a specific project is usually unknown a priori. Thus, in this paper, we propose a novel algorithm, BOIS (Bayesian-optimisation-based incentive selection), to learn the optimal structure and tune its parameters effectively. In detail, the learning and tuning problems are solved simultaneously by using online learning in combination with Bayesian optimisation. The results of our extensive simulations show that the performance of our algorithm is up to 85% of the optimal and up to 63% better than state-of-the-art benchmarks

High magnetisation, monodisperse and water-dispersible CoFe@Pt core/shell nanoparticles

High magnetisation and monodisperse CoFe alloy nanoparticles are desired for a wide range of biomedical applications. However, these CoFe nanoparticles are prone to oxidation, resulting in the deterioration of their magnetic properties. In the current work, CoFe alloy nanoparticles were prepared by thermal decomposition of cobalt and iron carbonyls in organic solvents at high temperatures. Using a seeded growth method, we successfully synthesised chemically stable CoFe@Pt core/shell nanostructures. The obtained core/shell nanoparticles have high saturation magnetisation up to 135 emu g−1. The magnetisation value of the core/shell nanoparticles remains 93 emu g−1 after being exposed to air for 12 weeks. Hydrophobic CoFe@Pt nanoparticles were rendered water-dispersible by encapsulating with poly(maleic anhydride-alt-1-octadecene) (PMAO). These nanoparticles were stable in water for at least 3 months and in a wide range of pH from 2 to 11

Intrathecal Immunoglobulin for treatment of adult patients with tetanus: A randomized controlled 2x2 factorial trial

Despite long-standing availability of an effective vaccine, tetanus remains a significant problem in many countries. Outcome depends on access to mechanical ventilation and intensive care facilities and in settings where these are limited, mortality remains high. Administration of tetanus antitoxin by the intramuscular route is recommended treatment for tetanus, but as the tetanus toxin acts within the central nervous system, it has been suggested that intrathecal administration of antitoxin may be beneficial. Previous studies have indicated benefit, but with the exception of one small trial no blinded studies have been performed. The objective of this study is to establish whether the addition of intrathecal tetanus antitoxin reduces the need for mechanical ventilation in patients with tetanus. Secondary objectives: to determine whether the addition of intrathecal tetanus antitoxin reduces autonomic nervous system dysfunction and length of hospital/ intensive care unit stay; whether the addition of intrathecal tetanus antitoxin in the treatment of tetanus is safe and cost-effective; to provide data to inform recommendation of human rather than equine antitoxin. This study will enroll adult patients (≥16 years old) with tetanus admitted to the Hospital for Tropical Diseases, Ho Chi Minh City. The study is a 2x2 factorial blinded randomized controlled trial. Eligible patients will be randomized in a 1:1:1:1 manner to the four treatment arms (intrathecal treatment and human intramuscular treatment, intrathecal treatment and equine intramuscular treatment, sham procedure and human intramuscular treatment, sham procedure and equine intramuscular treatment). Primary outcome measure will be requirement for mechanical ventilation. Secondary outcome measures: duration of hospital/ intensive care unit stay, duration of mechanical ventilation, in-hospital and 240-day mortality and disability, new antibiotic prescription, incidence of ventilator associated pneumonia and autonomic nervous system dysfunction, total dose of benzodiazepines and pipecuronium, and incidence of adverse events. Trial registration: ClinicalTrials.gov NCT02999815 Registration date: 21 December 2016

Interview-based sighting histories can inform regional conservation prioritization for highly threatened cryptic species

1. The use of robust ecological data to make evidence-based management decisions is frequently prevented by limited data quantity or quality, and local ecological knowledge (LEK) is increasingly seen as an important source of information for conservation. However, there has been little assessment of LEK's usefulness for informing prioritization and management of landscapes for threatened species, or assessing comparative species status across landscapes. 2. A large-scale interview survey in the Annamite Mountains (Vietnam and Lao PDR) compiled the first systematic LEK data set for saola Pseudoryx nghetinhensis, one of the world's rarest mammals, and eight other ungulates. Saola conservation is hindered by uncertainty over continued presence across much of its proposed distribution. We analysed comparative LEK-based last-sighting data across three landscapes to determine whether regional sighting histories support previous suggestions of landscape importance for saola conservation (Hue-Quang Nam: top-priority Vietnamese landscape; Pu Mat: lower priority Vietnamese landscape; Viengthong: high-priority Lao landscape) and whether they constitute an effective spatial prioritization tool for cryptic species management. 3. Wild pig and red muntjac may be the only Annamite ungulates with stable populations; the regional status of all other species appears to be worse. Saola have declined more severely and/or are significantly rarer than most other ungulates and have been seen by relatively few respondents. Saola were also frequently considered locally rarest or declining, and never as species that had not declined. 4. In contrast to other species, there are no regional differences in saola sighting histories, with continued persistence in all landscapes challenging suggestions that regional status differs greatly. Remnant populations persist in Vietnam despite heavy hunting, but even remote landscapes in Lao may be under intense pressure. 5. Synthesis and applications. Our local ecological knowledge data suggest that intact saola populations probably no longer exist, but individuals persist in all three landscapes, making management activities to reduce hunting pressure on ungulates in each landscape a conservation priority. Analysis of last-sighting histories can constitute an important conservation tool when robust data are otherwise unavailable, and collection of last-sighting records should be incorporated more widely into field studies and management of other highly threatened, cryptic species

Oseltamivir resistance during treatment of influenza A (H5N1) infection

Influenza A (H5N1) virus with an amino acid substitution in neuraminidase conferring high-level resistance to oseltamivir was isolated from two of eight Vietnamese patients during oseltamivir treatment. Both patients died of influenza A (H5N1) virus infection, despite early initiation of treatment in one patient. Surviving patients had rapid declines in the viral load to undetectable levels during treatment. These observations suggest that resistance can emerge during the currently recommended regimen of oseltamivir therapy and may be associated with clinical deterioration and that the strategy for the treatment of influenza A (H5N1) virus infection should include additional antiviral agents. Copyright © 2005 Massachusetts Medical Society.published_or_final_versio

The first genome sequences of human bocaviruses from Vietnam.

As part of an ongoing effort to generate complete genome sequences of hand, foot and mouth disease-causing enteroviruses directly from clinical specimens, two complete coding sequences and two partial genomic sequences of human bocavirus 1 (n=3) and 2 (n=1) were co-amplified and sequenced, representing the first genome sequences of human bocaviruses from Vietnam. The sequences may aid future study aiming at understanding the evolution of the pathogen

Hexa Histidine–Tagged Recombinant Human Cytoglobin Deactivates Hepatic Stellate Cells and Inhibits Liver Fibrosis by Scavenging Reactive Oxygen Species

BACKGROUND & AIMS: Anti-fibrotic therapy remains an unmet medical need in human chronic liver disease. We report the anti-fibrotic properties of cytoglobin (CYGB), a respiratory protein expressed in hepatic stellate cells (HSCs), the main cell type involved in liver fibrosis. APPROACH & RESULTS: Cygb-deficient mice which had bile duct ligation (BDL)-induced liver cholestasis or choline-deficient L-amino acid-defined (CDAA) diet-induced steatohepatitis significantly exacerbated liver damage, fibrosis and reactive oxygen species (ROS) formation. All these manifestations were attenuated in Cygb-overexpressing mice. We produced 6His-tagged recombinant human CYGB (His-CYGB), traced its bio-distribution and assessed its function in HSCs or in mice with advanced liver cirrhosis using thioacetamide (TAA) or 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). In cultured HSCs, extracellular His-CYGB was endocytosed and accumulated in endosomes via clathrin-mediated pathway. His-CYGB significantly impeded ROS formation spontaneously or in the presence of ROS inducers in HSCs, thus leading to the attenuation of collagen type I alpha 1 production and alpha-smooth muscle actin expression. Replacement the iron centre of the heme group with cobalt nullified the effect of His-CYGB. In addition, His-CYGB induced interferon-β secretion by HSCs which partly contributed to its anti-fibrotic function. Momelotinib incompletely reversed the effect of His-CYGB. Intravenously injected His-CYGB markedly suppressed liver inflammation, fibrosis and oxidative cell damage in TAA- or DDC-administered mice without adverse effects. RNA-seq analysis revealed the downregulation of inflammation and fibrosis-related genes and the upregulation of antioxidant genes in both cell culture and liver tissues. The injected His-CYGB predominantly localised to HSCs but not to macrophages, suggesting specific targeting effects. His-CYGB exhibited no toxicity in humanised liver chimeric PXB mice. CONCLUSIONS: His-CYGB could have anti-fibrotic clinical applications for human chronic liver diseases

Hidden attractors in fundamental problems and engineering models

Recently a concept of self-excited and hidden attractors was suggested: an attractor is called a self-excited attractor if its basin of attraction overlaps with neighborhood of an equilibrium, otherwise it is called a hidden attractor. For example, hidden attractors are attractors in systems with no equilibria or with only one stable equilibrium (a special case of multistability and coexistence of attractors). While coexisting self-excited attractors can be found using the standard computational procedure, there is no standard way of predicting the existence or coexistence of hidden attractors in a system. In this plenary survey lecture the concept of self-excited and hidden attractors is discussed, and various corresponding examples of self-excited and hidden attractors are considered