A Modular Millifluidic Platform for the Synthesis of Iron Oxide Nanoparticles with Control over Dissolved Gas and Flow Configuration

Gas–liquid reactions are poorly explored in the context of nanomaterials synthesis, despite evidence of significant effects of dissolved gas on nanoparticle properties. This applies to the aqueous synthesis of iron oxide nanoparticles, where gaseous reactants can influence reaction rate, particle size and crystal structure. Conventional batch reactors offer poor control of gas–liquid mass transfer due to lack of control on the gas–liquid interface and are often unsafe when used at high pressure. This work describes the design of a modular flow platform for the water-based synthesis of iron oxide nanoparticles through the oxidative hydrolysis of Fe2+ salts, targeting magnetic hyperthermia applications. Four different reactor systems were designed through the assembly of two modular units, allowing control over the type of gas dissolved in the solution, as well as the flow pattern within the reactor (single-phase and liquid–liquid two-phase flow). The two modular units consisted of a coiled millireactor and a tube-in-tube gas–liquid contactor. The straightforward pressurization of the system allows control over the concentration of gas dissolved in the reactive solution and the ability to operate the reactor at a temperature above the solvent boiling point. The variables controlled in the flow system (temperature, flow pattern and dissolved gaseous reactants) allowed full conversion of the iron precursor to magnetite/maghemite nanocrystals in just 3 min, as compared to several hours normally employed in batch. The single-phase configuration of the flow platform allowed the synthesis of particles with sizes between 26.5 nm (in the presence of carbon monoxide) and 34 nm. On the other hand, the liquid–liquid two-phase flow reactor showed possible evidence of interfacial absorption, leading to particles with different morphology compared to their batch counterpart. When exposed to an alternating magnetic field, the particles produced by the four flow systems showed ILP (intrinsic loss parameter) values between 1.2 and 2.7 nHm2/kg. Scale up by a factor of 5 of one of the configurations was also demonstrated. The scaled-up system led to the synthesis of nanoparticles of equivalent quality to those produced with the small-scale reactor system. The equivalence between the two systems is supported by a simple analysis of the transport phenomena in the small and large-scale setup

The Expanding Mycovirome of Aspergilli

© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Mycoviruses are viruses that infect fungi and are widespread across all major fungal taxa, exhibiting great biological diversity. Since their discovery in the 1960s, researchers have observed a myriad of fungal phenotypes altered due to mycoviral infection. In this review, we examine the nuanced world of mycoviruses in the context of the medically and agriculturally important fungal genus, Aspergillus. The advent of RNA sequencing has revealed a previous underestimate of viral prevalence in fungi, in particular linear single-stranded RNA viruses, and here we outline the diverse viral families known to date that contain mycoviruses infecting Aspergillus. Furthermore, we describe these novel mycoviruses, highlighting those with peculiar genome structures, such as a split RNA dependent RNA polymerase gene. Next, we delineate notable mycovirus-mediated phenotypes in Aspergillus, in particular reporting on observations of mycoviruses that affect their fungal host’s virulence and explore how this may relate to virus-mediated decreased stress tolerance. Furthermore, mycovirus effects on microbial competition and antifungal resistance are discussed. The factors that influence the manifestation of these phenotypes, such as temperature, fungal life stage, and infection with multiple viruses, among others, are also evaluated. In addition, we attempt to elucidate the molecular mechanisms that underpin these phenotypes, examining how mycoviruses can be targets, triggers, and even suppressors of RNA silencing and how this can affect fungal gene expression and phenotypes. Finally, we highlight the potential therapeutic applications of mycoviruses and how, in an approach analogous to bacteriophage therapy, their ability to produce hypovirulence in Aspergillus might be used to attenuate invasive aspergillosis infections in humans.Peer reviewe

A stochastic model for the evolution of the web allowing link deletion

Recently several authors have proposed stochastic evolutionary models for the growth of the web graph and other networks that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the ``rich get richer'' phenomenon. We present a generalisation of the basic model by allowing deletion of individual links and show that it also gives rise to a power-law distribution. We derive the mean-field equations for this stochastic model and show that by examining a snapshot of the distribution at the steady state of the model, we are able to tell whether any link deletion has taken place and estimate the link deletion probability. Our model enables us to gain some insight into the distribution of inlinks in the web graph, in particular it suggests a power-law exponent of approximately 2.15 rather than the widely published exponent of 2.1

Comparing Aspects Of The Process Quality In Six European Early Childhood Educational Settings

The European project ‘Early Change’ (http://earlychange.teithe.gr) attempts to evaluate the quality of early childhood education (ECE) environments of six European countries, Greece, Portugal, Finland, Denmark, Cyprus and Romania. The purpose of this paper is to compare the level of two dimensions of the process quality of these environments a) Space & Furnishings, and b) Personal Care Routines. Theorists, practitioners and researchers agree that in order to provide qualitative education to young children, one of the basic needs of all children must be met; that need is the protection of their health and their safety. A high quality early childhood education program must contain a safe and stimulating environment for the child (Lindsey, 1998). Such an environment includes indoor space, outdoor space, furniture, and room arrangement, and it is considered an integral part of a high quality early childhood program. 117 early educators from the six participating countries attended the training seminars about the evaluation of ECE quality using the Early Childhood Environmental Rating Scale-R (ECERS-R). The trained educators evaluated the 8 indicators of the subscale ‘space & furnishings’ and the six indicators of the subscale ‘personal care routines’ in approximately 600 early childhood classrooms from six European countries. The results of this study highlight the similarities and differences concerning the specific dimensions of the process quality of ECE environments in six European countries, and reflect the diversity of ECE environment across these countries. The findings of this study may provide a valuable insight to researchers and educational policy makers for an enhanced understanding of the cultural diversities and the strengthening of the common values and targets of the European Union

Co-precipitation synthesis of stable iron oxide nanoparticles with NaOH: New insights and continuous production via flow chemistry

Co-precipitation is by far the most common synthesis for magnetic iron oxide nanoparticles (IONPs), as cheap and environmentally friendly precursors and simple experimental procedures facilitate IONP production in many labs. Optimising co-precipitation syntheses remains challenging however, as particle formation mechanisms are not well understood. This is partly due to the rapid particle formation (within seconds) providing insufficient time to characterise initial precipitates. To overcome this limitation, a flow chemistry approach has been developed using steady-state operation to “freeze” transient reaction states locally. This allowed for the first time a comprehensive analysis of the early stages of co-precipitation syntheses via in-situ Small Angle X-ray Scattering and in-situ synchrotron X-Ray Diffraction. These studies revealed that after mixing the ferrous/ferric chloride precursor with the NaOH base solution, the most magnetic iron oxide phase forms within 5 s, the particle size changes only marginally afterwards, and co-precipitation and agglomeration occur simultaneously. As these agglomerates were too large to achieve colloidal stability via subsequent stabiliser addition, co-precipitated IONPs had to be de-agglomerated. This was achieved by adding the appropriate quantity of a citric acid solution which yielded within minutes colloidally stable IONP solutions around a neutral pH value. The new insights into the particle formation and the novel stabilisation procedure (not requiring any ultra-sonication or washing step) allowed to design a multistage flow reactor to synthesise and stabilise IONPs continuously with a residence time of less than 5 min. This reactor was robust against fouling and produced stable IONP solutions (of ~1.5 mg particles per ml) reproducibly via fast mixing ( 500 ml/h) for low materials cost

Interpretation training to target repetitive negative thinking in generalized anxiety disorder and depression

Objective: Repetitive negative thinking (RNT) e.g., worry in generalized anxiety disorder (GAD) and rumination in depression, is often targeted during psychological treatments. To test the hypothesis that negative interpretation bias contributes to worry and rumination, we assessed the effects of inducing more positive interpretations in reducing RNT. Method: Volunteers diagnosed with GAD (66) or Depression (65) were randomly allocated to one of two versions of Cognitive Bias Modification (CBM-I), either with or without RNT priming prior to training), or a control condition, each involving 10 internet-delivered sessions. Outcome measures of interpretation bias, a behavioral RNT task and self-reported worry, rumination, anxiety and depression were obtained at baseline, after home-based training and at 1-month follow up (self-report questionnaires only). Results: CBM-I training, across diagnostic groups, promoted a more positive interpretation bias and led to reductions in worry, rumination, and depressive symptoms, which were maintained at follow up. Anxiety symptoms were reduced only in the GAD group at follow up. There were no differences between CBM-I versions; brief priming of RNT did not influence CBM-I effectiveness. Level of interpretation bias post training partially mediated the effects of CBM-I on follow-up questionnaire scores. Conclusions: In contrast to some recent failures to demonstrate improvements following internet-delivered CBM, we found that self-reported RNT and negative mood were reduced by CBM-I. This is consistent with a causal role for negative interpretation bias in both worry and rumination, suggesting a useful role for CBM-I within treatments for anxiety and depression

Effects of modifying interpretation bias on transdiagnostic repetitive negative thinking.

Objective: Repetitive negative thinking (RNT; e.g., worry and rumination) is common across emotional disorders, as is the tendency to generate negative interpretations (interpretation bias). Ameliorating negative interpretations via cognitive bias modification of interpretations (CBM-I) reduces worry/rumination, and improves mood in people diagnosed with generalized anxiety disorder (GAD) or depression. We investigated whether these findings generalize to high worry or rumination populations, irrespective of diagnosis, and whether effects are increased by enhancing emotional engagement with training with active generation of positive resolutions of ambiguity and imagery. Method: Community volunteers with excessive worry and/or rumination, who were above clinical cut-off on anxiety and/or depression measures, were allocated to an active control condition (n = 54), interpretation training condition with prior activation of RNT (CBM_RNT; n = 54), or training condition augmented with positive outcome generation and imagery (CBM_ENH; n = 53). Interpretation bias, RNT, and mood were assessed before and following 10 Internet-based sessions completed within a 1-month period. RNT and mood questionnaires were also completed at 1-month follow-up. Results: After training, both forms of CBM-I (vs. control) facilitated more positive interpretations and reduced negative intrusions during a worry task. At 1-month follow-up, anxiety, depression, RNT, and worry in the past week were lower in the CBM-I than control conditions, but not rumination or trait worry. Compared with standard CBM-I, the augmented form facilitated more positive interpretations, reduced negative intrusions after training, and reduced trait rumination at 1-month follow-up, but it did not augment effects on trait worry, anxiety or depression. Conclusions: Interpretation bias maintains transdiagnostic RNT and Internet-based CBM-I can reduce longer-term RNT. (PsycInfo Database Record (c) 2020 APA, all rights reserved

Studies on the virome of the entomopathogenic fungus Beauveria bassiana reveal novel dsRNA elements and mild hypervirulence.

© 2017 Kotta-Loizou, Coutts. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Kotta-Loizou I, Coutts RHA (2017) 'Studies on the Virome of the Entomopathogenic Fungus Beauveria bassiana Reveal Novel dsRNA Elements and Mild Hypervirulence', PLoS Pathogens, 13(1): e1006183. doi:10.1371/journal.ppat.1006183The entomopathogenic fungus Beauveria bassiana has a wide host range and is used as a biocontrol agent against arthropod pests. Mycoviruses have been described in phytopathogenic fungi while in entomopathogenic fungi their presence has been reported only rarely. Here we show that 21.3% of a collection of B. bassiana isolates sourced from worldwide locations, harbor dsRNA elements. Molecular characterization of these elements revealed the prevalence of mycoviruses belonging to the Partitiviridae and Totiviridae families, the smallest reported virus to date, belonging to the family Narnaviridae, and viruses unassigned to a family or genus. Of particular importance is the discovery of members of a newly proposed family Polymycoviridae in B. bassiana. Polymycoviruses, previously designated as tetramycoviruses, consist of four non-conventionally encapsidated capped dsRNAs. The presence of additional non-homologous genomic segments in B. bassiana polymycoviruses and other fungi illustrates the unprecedented dynamic nature of the viral genome. Finally, a comparison of virus-free and virus-infected isogenic lines derived from an exemplar B. bassiana isolate revealed a mild hypervirulent effect of mycoviruses on the growth of their host isolate and on its pathogenicity against the greater wax moth Galleria mellonella, highlighting for the first time the potential of mycoviruses as enhancers of biocontrol agents.Peer reviewedFinal Published versio

Carotid Ultrasound Boundary Study (CUBS): An Open Multicenter Analysis of Computerized Intima–Media Thickness Measurement Systems and Their Clinical Impact

Common carotid intima–media thickness (CIMT) is a commonly used marker for atherosclerosis and is often computed in carotid ultrasound images. An analysis of different computerized techniques for CIMT measurement and their clinical impacts on the same patient data set is lacking. Here we compared and assessed five computerized CIMT algorithms against three expert analysts’ manual measurements on a data set of 1088 patients from two centers. Inter- and intra-observer variability was assessed, and the computerized CIMT values were compared with those manually obtained. The CIMT measurements were used to assess the correlation with clinical parameters, cardiovascular event prediction through a generalized linear model and the Kaplan–Meier hazard ratio. CIMT measurements obtained with a skilled analyst's segmentation and the computerized segmentation were comparable in statistical analyses, suggesting they can be used interchangeably for CIMT quantification and clinical outcome investigation. To facilitate future studies, the entire data set used is made publicly available for the community at http://dx.doi.org/10.17632/fpv535fss7.1