575 research outputs found
Apparent digestibility of insect protein meals for rainbow trout
Insect meals are considered to be promising future ingredients for aquaculture feeds. In past feeding trials in rainbow trout, insect meals were included in diets only on the basis of their nutrients content and energy density without taking into account their biological availability due to the lack of their digestible values. Apparent digestibility (ADC) provides good indication of the bioavailability of nutrients and energy thus providing rational basis for the correct inclusion of feedstuffs. The aim of this research was to assess, in an in vivo trial on rainbow trout, the ADC of five full fat insect meals: one Tenebrio molitor (TM), two Hermetia illucens obtained through two different process (HI1 and HI2), one Musca domestica (MD), and one Alphitobius diaperinus (AD). Fish were fed a high-quality reference diet (R) and test diets obtained mixing the R diet with each of the test ingredients at a ratio of 70:30. Diets contained 1% celite as inert marker. Fish were fed to visual satiety twice a day and faecal samples collected using a continuous automatic device. Faeces were freeze dried and frozen (-20 \ub0C) until analyses. The ADC of dry matter, crude protein and ether extract of each insect meal diet were calculated. ADC for dry matter varied between 70.07 (HI1) and 80.85 (TM). ADC for protein was above 84% in all treatments and resulted the highest in MD, TM and AD treatments. Ether extract apparent digestibility significantly differed among diets with the highest value reported for TM treatment. All treatments reported values higher than 96%. Observed differences could be due to the insect species and meal treatment but in general, tested insect meals were highly digestible for rainbow trout. The results from this research could be useful to optimize the diet formulation
MIL-91(Ti), a small pore metal-organic framework which fulfils several criteria : an upscaled green synthesis, excellent water stability, high CO2 selectivity and fast CO2 transport
The research leading to these results has received funding from the European Community Seventh Framework Program (FP7/2007-2013) [grant agreement number 608490] (project M4CO2) and from the ANR ‘CHESDENS’ (ANR-13-SEED-0001-01).A multidisciplinary approach combining advanced experimental and modelling tools was undertaken to characterize the promises of a small-pore type Ti-based metal-organic framework, MIL-91(Ti) for CO2 capture. This material was prepared using two synthesis strategies, i.e. under hydrothermal conditions and under reflux, and its single component adsorption behaviour with respect to CO2, CH4 and N2 was first revealed by gravimetry measurements. This hydrophilic and highly water stable MOF is characterized by a relatively high CO2 adsorption enthalpy. Molecular simulations combined with in situ powder X-ray diffraction evidenced that this is due to the combined interaction of this probe with N-H and P-O groups in the phosphonate linker. High CO2 selectivities in the presence of either N2 or CH4 were also predicted and confirmed by co-adsorption measurements. The possibility to prepare this sample under reflux represents an environmentally friendly route which can easily be upscaled. This green synthesis route, excellent water stability, high selectivities and relatively fast transport kinetics of CO2 are significant points rendering this sample of utmost interest for CO2 capture.PostprintPostprintPeer reviewe
Photochromism, Electrical Properties, and Structural Investigations of a Series of Hydrated Methylviologen Halobismuthate Hybrids: Influence of the Anionic Oligomer Size and Iodide Doping on the Photoinduced Properties and on the Dehydration Process
Syntheses, X-ray structural analyses, thermal behaviors, photochromism, and electrical properties of a series of methylviologen (MV2+) halobismuthate hybrids, namely, (MV)3[Bi4Cl18](H2O)y (1a, y~1.7), (MV)4[Bi6Cl26](H2O)y (2a, y~1.7), (MV)4[Bi6Cl25.6I0.4](H2O)y (3a, y~1.5), and (MV)4[Bi6Cl24.6I1.4](H2O)y (4a, y~1.3), are reported. Because of the thermal effect of a UV lamp or as a result of being heated up to 100 °C, all of the above compounds undergo a complete (1a, 2a, and 3a) or a partial (4a) dehydration together, in 2a and 3a, with an impressive structural reorganization involving a 90° rotation of methylviologen dimers and, in 3a, a new Cl/I distribution, finally leading to (MV)3[Bi4Cl18] (1b), (MV)4[Bi6Cl26] (2b), (MV)4[Bi6Cl25.6I0.4] (3b), and (MV)4[Bi6Cl24.6I1.4](H2O)x (4a, x ~ 0.65), respectively. In its turn, 4a (x ~ 0.65) undergoes an abrupt structural change at 160 °C when water molecules are completely removed, leading to (MV)4[Bi6Cl24.6I1.4] (4b). Obviously, the two first dehydrated phases can be considered as the n = 2 (1b) and n = 3 (2b) members of the (MV)(2n+2)/2[Bi2nCl8n+2] family, and the ultimate member (n = ∞) with an infinite 1D double-chain inorganic framework, namely, (MV)[Bi2Cl8], has already been reported. According to the results of structural refinements, some positions of the Cl atoms in the [Bi6Cl26]8− anionic cluster of 3a and 4a have been occupied by I atoms, finally leading to iodide-doped materials of the 2a type (percentage of doping: 3a, 1.5%; 4a, 5.4%). Upon UV irradiation, yellow crystals of 2a and 3a (which become 2b and 3b because of the thermal effect of the UV lamp) or yellow crystals of 2b, 3b, and 4a undergo a color change to black crystals (in the case of 2b), as observed in (MV)[Bi2Cl8], or light-brown crystals (in the cases of 3b and 4a). These photochromic properties are probably due to the photoinduced electron transfer from the anionic part to the methylviologen dications. In contrast, no color change is observed when yellow crystals of 1a or 1b and the iodide-doped (MV)[Bi2Cl8−εIε] material are irradiated. Because the relative positions of methylviologen to the host anionic frameworks are comparable in all structures (the N···Cl distances are about 3.4 Å), these results indicate that such kinds of photochemical reactions depend on the dimension of the anionic networks, as well as the iodide doping. The single-crystal electrical conductivity measurements of 2b before and after irradiation were carried out between 150 and 393 K. The results prove that both of them are semiconductors with weak room temperature conductivity and that the band gap of the irradiated crystal (2b, 0.35 eV) is much smaller than that of the original hybrid 2a (1.0 eV)
Three-dimensional lanthanide-organic frameworks based on di-, tetra-, and hexameric clusters
Three-dimensional lanthanide-organic frameworks formulated as (CH3)2NH2[Ln(pydc)2] · 1/2H2O [Ln3+ ) Eu3+ (1a)
or Er3+ (1b); pydc2- corresponds to the diprotonated residue of 2,5-pyridinedicarboxylic acid (H2pydc)], [Er4(OH)4(pydc)4(H2O)3] ·H2O
(2), and [PrIII
2PrIV
1.25O(OH)3(pydc)3] (3) have been isolated from typical solvothermal (1a and 1b in N,N-dimethylformamide -
DMF) and hydrothermal (2 and 3) syntheses. Materials were characterized in the solid state using single-crystal X-ray diffraction,
thermogravimetric analysis, vibrational spectroscopy (FT-IR and FT-Raman), electron microscopy, and CHN elemental analysis.
While synthesis in DMF promotes the formation of centrosymmetric dimeric units, which act as building blocks in the construction
of anionic ∞
3{[Ln(pydc)2]-} frameworks having the channels filled by the charge-balancing (CH3)2NH2
+ cations generated in situ by
the solvolysis of DMF, the use of water as the solvent medium promotes clustering of the lanthanide centers: structures of 2 and 3
contain instead tetrameric [Er4(μ3-OH)4]8+ and hexameric |Pr6(μ3-O)2(μ3-OH)6| clusters which act as the building blocks of the networks,
and are bridged by the H2-xpydcx- residues. It is demonstrated that this modular approach is reflected in the topological nature of
the materials inducing 4-, 8-, and 14-connected uninodal networks (the nodes being the centers of gravity of the clusters) with
topologies identical to those of diamond (family 1), and framework types bct (for 2) and bcu-x (for 3), respectively. The
thermogravimetric studies of compound 3 further reveal a significant weight increase between ambient temperature and 450 °C with
this being correlated with the uptake of oxygen from the surrounding environment by the praseodymium oxide inorganic core
Preliminary Examination of the System Fly Ash-Bottom Ash-Flue Gas Desulphurization Gypsum-Portland Cement-Water for Road Construction
This paper describes an investigation into the use of three power plant wastes: fly ash, flue gas desulphurization gypsum, and bottom ash for subbase layers in road construction. Two kinds of mixtures of these wastes with Portland cement and water were made: first with fly ash consisting of coarser particles (<1.651 mm) and second with fly ash consisting of smaller particles (<0.42 mm). The mass ratio of fly ash-Portland cement-flue gas desulphurization gypsum-bottom ash was the same (3 : 1 : 1 : 5) in both mixtures. For both mixtures, the compressive strength, the mineralogical composition, and the leaching characteristics were determined at different times, 7 and 28 days, after preparation. The obtained results showed that both mixtures could find a potential use for subbase layers in road construction
Mineralogical Transformations in Copper Concentrate Roasting in Fluo-Solid Reactor
This work presents the results of investigation process of copper concentrate roasting in fluo-solid reactor with the aim of studying a transformation degree of primary ore minerals under various technological parameters. Input material (charge) and roasting products (calcine) were investigated by x-ray diffraction, ore microscopy and chemical analysis. The investigation results have shown that reaction of mineral transformation are not completed, i.e. they are developed only partially (12 - 22%) what is a consequence of insufficient long heating, unsuitable temperature or unfilled other parameters as well as non-uniform grain size
Evaluating the impact of artificial intelligence-assisted image analysis on the diagnostic accuracy of front-line clinicians in detecting fractures on plain X-rays (FRACT-AI): protocol for a prospective observational study.
Missed fractures are the most frequent diagnostic error attributed to clinicians in UK emergency departments and a significant cause of patient morbidity. Recently, advances in computer vision have led to artificial intelligence (AI)-enhanced model developments, which can support clinicians in the detection of fractures. Previous research has shown these models to have promising effects on diagnostic performance, but their impact on the diagnostic accuracy of clinicians in the National Health Service (NHS) setting has not yet been fully evaluated. A dataset of 500 plain radiographs derived from Oxford University Hospitals (OUH) NHS Foundation Trust will be collated to include all bones except the skull, facial bones and cervical spine. The dataset will be split evenly between radiographs showing one or more fractures and those without. The reference for each image will be established through independent review by two senior musculoskeletal radiologists. A third senior radiologist will resolve disagreements between two primary radiologists. The dataset will be analysed by a commercially available AI tool, BoneView (Gleamer, Paris, France), and its accuracy for detecting fractures will be determined with reference to the ground truth diagnosis. We will undertake a multiple case multiple reader study in which clinicians interpret all images without AI support, then repeat the process with access to AI algorithm output following a 4-week washout. 18 clinicians will be recruited as readers from four hospitals in England, from six distinct clinical groups, each with three levels of seniority (early-stage, mid-stage and later-stage career). Changes in the accuracy, confidence and speed of reporting will be compared with and without AI support. Readers will use a secure web-based DICOM (Digital Imaging and Communications in Medicine) viewer (www.raiqc.com), allowing radiograph viewing and abnormality identification. Pooled analyses will be reported for overall reader performance as well as for subgroups including clinical role, level of seniority, pathological finding and difficulty of image. The study has been approved by the UK Healthcare Research Authority (IRAS 310995, approved on 13 December 2022). The use of anonymised retrospective radiographs has been authorised by OUH NHS Foundation Trust. The results will be presented at relevant conferences and published in a peer-reviewed journal. This study is registered with ISRCTN (ISRCTN19562541) and ClinicalTrials.gov (NCT06130397). The paper reports the results of a substudy of STEDI2 (Simulation Training for Emergency Department Imaging Phase 2). [Abstract copyright: © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.
Viral Small Interfering RNAs Target Host Genes to Mediate Disease Symptoms in Plants
The Cucumber mosaic virus (CMV) Y-satellite RNA (Y-Sat) has a
small non-protein-coding RNA genome that induces yellowing symptoms in infected
Nicotiana tabacum (tobacco). How this RNA pathogen induces
such symptoms has been a longstanding question. We show that the yellowing
symptoms are a result of small interfering RNA (siRNA)-directed RNA silencing of
the chlorophyll biosynthetic gene, CHLI. The CHLI mRNA contains a 22-nucleotide
(nt) complementary sequence to the Y-Sat genome, and in Y-Sat-infected plants,
CHLI expression is dramatically down-regulated. Small RNA sequencing and
5′ RACE analyses confirmed that this 22-nt sequence was targeted for mRNA
cleavage by Y-Sat-derived siRNAs. Transformation of tobacco with a RNA
interference (RNAi) vector targeting CHLI induced Y-Sat-like symptoms. In
addition, the symptoms of Y-Sat infection can be completely prevented by
transforming tobacco with a silencing-resistant variant of the CHLI gene. These
results suggest that siRNA-directed silencing of CHLI is solely responsible for
the Y-Sat-induced symptoms. Furthermore, we demonstrate that two
Nicotiana species, which do not develop yellowing symptoms
upon Y-Sat infection, contain a single nucleotide polymorphism within the
siRNA-targeted CHLI sequence. This suggests that the previously observed species
specificity of Y-Sat-induced symptoms is due to natural sequence variation in
the CHLI gene, preventing CHLI silencing in species with a mismatch to the Y-Sat
siRNA. Taken together, these findings provide the first demonstration of small
RNA-mediated viral disease symptom production and offer an explanation of the
species specificity of the viral disease
- …
