So far, compliance with ISO 3632 standard specifications for top-quality saffron guarantees good agricultural and post-harvest production practices. Tracking early-stage oxidation remains ...challenging. Our study aims to address this issue by exploring the visible, fluorescence, and near-infrared spectra of category I saffron. Using a multi-spectral sensor, we tested fresh and artificially aged saffron in powder form. High autofluorescence intensities at 600–700 nm allowed calibration for the ‘content of aged saffron’. Samples with minimum coloring strength (200–220 units) were classified as 70% aged, while those exceeding maximum aroma strength (50 units) as 100% aged. Consistent patterns across origin, age, and processing history indicated potential for objectively assessing early-oxidation markers. Further analyses uncovered multiple contributing fluorophores, including cis-apocarotenoids, correlated with FTIR-based aging markers. Our findings underscore that sensing autofluorescence of traded saffron presents an innovative quality diagnostic approach, paving new research pathways for assessing the remaining shelf-life along its supply chain.
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•A sensor-based approach to tracing early oxidation of traded saffron.•Increasing autofluorescence as a novel quality indicator.•Strong diagnostic potential based on ‘content of aged saffron’.•Multiple contributing fluorophores including cis-apocarotenoids.•Prospects for objective assessment of saffron shelf-life.
A combined experimental and theoretical study provides a rationale of the chemical and physical behavior for Pt(II)-acetonitrile and -benzonitrile complexes. The increased reactivity of the nitrile ...ligands, after coordination to Pt(II), can be explained by the energy decreasing of the ligands’ LUMOs. The theoretical models are able to reproduce the spectroscopic observations and show an excellent agreement between crystallographic data and optimized structures, nicely supporting the proposed models. Display omitted
•A combined experimental and theoretical study on Platinum(II) nitrile complexes.•Spectroscopic characterization including CP/MAS NMR data.•Redetermination of X-ray structures of cis-and trans-PtCl2(NCPh)2 and cis-PtCl2(NCCH3)2.•Theoretical study for a rationale of spectroscopic data.•Theoretical study for a rationale of the reactivity towards nucleophiles.
The spectroscopic characterization of cis- and trans-PtCl2(NCR)2 (R=CH3, Ph, CH2Ph) was reported in solid state and solution phase. Moreover, the X-ray structures of cis-PtCl2(NCCH3)2, cis- and trans-PtCl2(NCPh)2 were redetermined at low temperature. FT-IR and NMR showed a blue-shift and a slight shielding of the νCN and δ(13CCN) values, respectively, in a counterintuitive way with respect to the well known improved reactivity towards nucleophiles of nitriles ligands coordinated to platinum(II), when compared to their free forms. These spectroscopic behaviors were also confirmed by theoretical experiments at DFT level. Moreover, DFT approach showed that the increased reactivity of the nitrile ligands, after coordination to Pt(II), can be explained by the energy decreasing of the ligands’ LUMOs, instead of an increased polarization of the CN bond, accordingly with the orbital control model previously proposed for trans-PtCl2(MeCN)2. Finally, bond analysis also discarded the occurrence of Pt→N back-donation.
The combined experimental and theoretical study herein reported, provides a rationale of the chemical and physical behavior for Pt(II)-acetonitrile and -benzonitrile complexes, proving to be a potential tool to set suitable based-nitrile intermediates for the synthesis of new organometallic derivatives.
Summary
Most Gram‐negative bacteria assemble lipopolysaccharides (LPS) on their surface to form a permeability barrier against many antimicrobials. LPS is synthesized at the inner membrane and then ...transported to the outer leaflet of the outer membrane. Although the overall LPS structure is conserved, LPS molecules can differ in composition at the species and strain level. Some bacteria also regulate when to modify phosphates on LPS at the inner membrane in order to become resistant to cationic antimicrobial peptides. The multi‐protein Lpt trans‐envelope machine, which transports LPS from the inner to the outer membrane, must therefore handle a variety of substrates. The most poorly understood step in LPS transport is how the ATP‐binding cassette LptB2FG transporter extracts LPS from the inner membrane. Here, we define residue K34 in LptG as a site within the structural cavity of the Escherichia coli LptB2FG transporter that interacts electrostatically with phosphates on unmodified LPS. Alterations to this residue cause transport defects that are suppressed by the activation of the BasSR two‐component signaling system, which results in modifications to the LPS phosphates. We also show this residue is part of a larger site in LptG that differentially contributes to the transport of unmodified and modified LPS.
Gram‐negative bacteria are naturally resistant to many antimicrobials because they cover their surface with the glycolipid LPS. It remains unknown how newly synthesized LPS is extracted from the cytoplasmic membrane by an ATP‐binding cassette transporter so that it can be routed to the cell surface by the trans‐envelope Lpt machine. This study identifies a substrate‐binding domain in a membrane component of the Escherichia coli Lpt transporter that is crucial for LPS extraction.
In this study, a series of new epoxy/clay nanocomposites (ECN) has been prepared and characterized in order to investigate the properties and compare the effect of the unmodified Moroccan clay on the ...structure and properties of the composite materials. Five natural clays have been used to reinforce the neat epoxy resin with 1% wt and 5% wt achieving the clay dispersion only through strong milling and mechanical stirring without previous organic modifications of the clays. The quality of clay dispersion in the epoxy matrix and the morphology of nanocomposites have been studied by transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), and X-ray diffraction (XRD). The mechanical and thermal properties have also been investigated. The antimicrobial activity of the nanocomposites has been tested against E. coli and S. aureus in order to evaluate their applicability as advanced antimicrobial materials. The results showed that the epoxy/crude clay nanocomposites exhibited a high inhibition action attending 99% against both bacteria in the case of the clay labeled A5.
•Dryed tannery wastewater treatment may self-heat, up to combustion.•SEM analysis revealed elemental S crystals.•FeS addition enhance the solids reactivity, while S prolongs it.•Ca(OH)2, Na2CO3, ...NaHCO3, FeCl2, EDTA, NaClO can limit or prevent self-heating.•The best prevention is reduction of S and Fe from the dried sludge.
We studied the spontaneous heating of dried sludge produced by treating wastewater mainly originating from tanneries. Heating up to burning has been observed in the presence of air and moisture, starting at ambient temperature. To understand and prevent the process we combined chemical and morphological analyses (ESEM) with thermal activity monitoring in insulated vessels. Selective additions of chemicals, either to amplify or depress the reactivity, have been used to investigate and identify both the chemical mechanism causing the sludge self-heating, and a prevention or a mitigation strategy. FeS additions accelerate the onset of reactivity, while S sustains it over time. On the contrary, Ca(OH)2, Na2CO3, NaHCO3, FeCl2, EDTA, NaClO can limit, up to completely preventing, the exothermic activity. All the experimental evidences show that the reactions supporting the dried sludge self-heating involve the Fe/S/O system. The total suppression of the reactivity requires amounts of additives that are industrially incompatible with waste reduction and economics. The best prevention requires reduction or removal of S and Fe from the dried solid matrix.
We describe a novel method to achieve a universal, massive, and fully automated analysis of cell motility behaviours, starting from time-lapse microscopy images. The approach was inspired by the ...recent successes in application of machine learning for style recognition in paintings and artistic style transfer. The originality of the method relies i) on the generation of atlas from the collection of single-cell trajectories in order to visually encode the multiple descriptors of cell motility, and ii) on the application of pre-trained Deep Learning Convolutional Neural Network architecture in order to extract relevant features to be used for classification tasks from this visual atlas. Validation tests were conducted on two different cell motility scenarios: 1) a 3D biomimetic gels of immune cells, co-cultured with breast cancer cells in organ-on-chip devices, upon treatment with an immunotherapy drug; 2) Petri dishes of clustered prostate cancer cells, upon treatment with a chemotherapy drug. For each scenario, single-cell trajectories are very accurately classified according to the presence or not of the drugs. This original approach demonstrates the existence of universal features in cell motility (a so called "motility style") which are identified by the DL approach in the rationale of discovering the unknown message in cell trajectories.
Dengue infections represent one of the most prevalent arthropod-borne diseases worldwide, causing a wide spectrum of clinical outcomes. Engineered infectious clone is an important tool to study ...Dengue virus (DENV) biology. Functional full-length cDNA clones have been constructed for many positive-strand RNA viruses and have provided valuable tools for studying the molecular mechanisms involved in viral genome replication, virion assembly, virus pathogenesis and vaccine development. We report herein the successful development of an infectious clone from a primary Brazilian isolate of dengue virus 3 (DENV3) of the genotype III. Using a two-plasmid strategy, DENV3 genome was divided in two parts and cloned separately into a yeast-bacteria shuttle vector. All plasmids were assembled in yeast by homologous recombination technique and a full-length template for transcription was obtained by in vitro ligation of the two parts of the genome. Transcript-derived DENV3 is infectious upon transfection into BHK-21 cells and in vitro characterization confirmed its identity. Growth kinetics of transcript-derived DENV3 was indistinguishable from wild type DENV3. This system is a powerful tool that will help shed light on molecular features of DENV biology, as the relationship of specific mutations and DENV pathogenesis.
Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost ...importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies. Here, we report the construction of a recombinant yellow fever virus (YFV) expressing Gaussia luciferase (GLuc) (YFV-GLuc). We show, through RT-PCR, sequencing and measurement of GLuc activity, that stability of the heterologous gene was maintained after six passages. Furthermore, a direct association between GLuc expression and viral replication was observed (r2=0.9967), indicating that measurement of GLuc activity may be used to assess viral replication in different applications. In addition, we evaluated the use of the recombinant virus in an antiviral assay with recombinant human alfa-2b interferon. A 60% inhibition of GLuc expression was observed in cells infected with YFV-GLuc and incubated with IFN alfa-2b. Previously tested on YFV inhibition by plaque assays indicated a similar fold-decrease in viral replication. These results are valuable as they show the stability of YFV-GLuc and one of several possible applications of this construct.
A review has been made of all the country update papers submitted to the World Geothermal Congress 2005 (WGC2005) from countries in which geothermal electricity is currently being generated. The most ...significant data to emerge from these papers, and from follow-up contacts with representatives of these countries, are: (1) a total of 24 countries now generate electricity from geothermal resources; (2) the total installed capacity worldwide is approximately 8930
MW
e, corresponding to about 8030
MW
e running capacity and electric energy production is nearly 57,000
GWh (early 2005 data); (3) Costa Rica, France (Guadeloupe), Iceland, Indonesia, Italy
1
1
Although the increase in installed capacity is small, 10 new units totaling 254
MW
e have been installed in Italy, to replace old and obsolete units.
, Kenya, Mexico, Nicaragua, Russia, and the USA have increased the capacity of their power plant installations by more than 10% with respect to the year 2000; (4) the new members of the geothermal electricity generating community comprise Austria, Germany and Papua New Guinea; (5) the installed capacity in Argentina and Greece is now null since their geothermal power plants have been dismantled; (6) nineteen countries have carried out significant geothermal drilling operations since 2000, with 307 new wells drilled.
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