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131.
Pascal I. Binda Ewan E. Delbridge Prof. Dr. Divine T. Dugah Brian W. Skelton Allan H. White 《无机化学与普通化学杂志》2008,634(2):325-334
The structural characterizations of the potassium complexes of a pair of dianionic bis(phenolate) ligands, {LR = [?OC6H2(2,4‐But)(6‐CH2)]2NCH2CH2R} R = NMe2, OMe, crystallized from 1,2,‐dimethoxyethane (DME) are recorded, showing them to take the binuclear form [K2LR(DME)3]. A pair of neutral binuclear heterobimetallic isotypic complexes are defined with ytterbium(III), with phenol, as sodium salts, of the form [Yb(LR)(OPh)2Na(DME)(HOPh)], and a further array with samarium(III), of the (partially protonated) form [Sm(LOMe)2Na(OH2)]. A further complex, [Na(DME)3][Yb(*Lpy)2], results from an unusual ligand reduction by an ytterbium(II) species to give a new dianionic Schiff base ligand which is coordinated to ytterbium(III) {*Lpy = ?OC6H2(2,4‐But)(6‐CH=N‐CH‐2‐C6H4N)}. 相似文献
132.
Tom Ruttink Rolinde Demeyer Elke Van Gulck Bart Van Droogenbroeck Maddalena Querci Isabel Taverniers Marc De Loose 《Analytical and bioanalytical chemistry》2010,396(6):2073-2089
Competent laboratories monitor genetically modified organisms (GMOs) and products derived thereof in the food and feed chain
in the framework of labeling and traceability legislation. In addition, screening is performed to detect the unauthorized
presence of GMOs including asynchronously authorized GMOs or GMOs that are not officially registered for commercialization
(unknown GMOs). Currently, unauthorized or unknown events are detected by screening blind samples for commonly used transgenic
elements, such as p35S or t-nos. If (1) positive detection of such screening elements shows the presence of transgenic material and (2) all known GMOs are
tested by event-specific methods but are not detected, then the presence of an unknown GMO is inferred. However, such evidence
is indirect because it is based on negative observations and inconclusive because the procedure does not identify the causative
event per se. In addition, detection of unknown events is hampered in products that also contain known authorized events.
Here, we outline alternative approaches for analytical detection and GMO identification and develop new methods to complement
the existing routine screening procedure. We developed a fluorescent anchor-polymerase chain reaction (PCR) method for the
identification of the sequences flanking the p35S and t-nos screening elements. Thus, anchor-PCR fingerprinting allows the detection of unique discriminative signals per event. In addition,
we established a collection of in silico calculated fingerprints of known events to support interpretation of experimentally
generated anchor-PCR GM fingerprints of blind samples. Here, we first describe the molecular characterization of a novel GMO,
which expresses recombinant human intrinsic factor in Arabidopsis thaliana. Next, we purposefully treated the novel GMO as a blind sample to simulate how the new methods lead to the molecular identification
of a novel unknown event without prior knowledge of its transgene sequence. The results demonstrate that the new methods complement
routine screening procedures by providing direct conclusive evidence and may also be useful to resolve masking of unknown
events by known events. 相似文献
133.
Dr. Gabriele Di Carlo Dr. Alessio Orbelli Biroli Prof. Maddalena Pizzotti Dr. Francesca Tessore Dr. Vanira Trifiletti Dr. Riccardo Ruffo Prof. Alessandro Abbotto Dr. Anna Amat Dr. Filippo De Angelis Prof. Patrizia R. Mussini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(32):10723-10740
A facile and fast approach, based on microwave‐enhanced Sonogashira coupling, has been employed to obtain in good yields both mono‐ and, for the first time, disubstituted push–pull ZnII porphyrinates bearing a variety of ethynylphenyl moieties at the β‐pyrrolic position(s). Furthermore, a comparative experimental, electrochemical, and theoretical investigation has been carried out on these β‐mono‐ or disubstituted ZnII porphyrinates and meso‐disubstituted push–pull ZnII porphyrinates. We have obtained evidence that, although the HOMO–LUMO energy gap of the meso‐substituted push–pull dyes is lower, so that charge transfer along the push–pull system therein is easier, the β‐mono‐ or disubstituted push–pull porphyrinic dyes show comparable or better efficiencies when acting as sensitizers in DSSCs. This behavior is apparently not attributable to more intense B and Q bands, but rather to more facile charge injection. This is suggested by the DFT electron distribution in a model of a β‐monosubstituted porphyrinic dye interacting with a TiO2 surface and by the positive effect of the β substitution on the incident photon‐to‐current conversion efficiency (IPCE) spectra, which show a significant intensity over a broad wavelength range (350–650 nm). In contrast, meso‐substitution produces IPCE spectra with two less intense and well‐separated peaks. The positive effect exerted by a cyanoacrylic acid group attached to the ethynylphenyl substituent has been analyzed by a photophysical and theoretical approach. This provided supporting evidence of a contribution from charge‐transfer transitions to both the B and Q bands, thus producing, through conjugation, excited electrons close to the carboxylic anchoring group. Finally, the straightforward and effective synthetic procedures developed, as well as the efficiencies observed by photoelectrochemical measurements, make the described β‐monosubstituted ZnII porphyrinates extremely promising sensitizers for use in DSSCs. 相似文献
134.
135.
The article investigates the ICT policies of characteristically political instable Italy in the wake of the (dis)continuous flood of government reforms that began in the early 1990s. Using the case of the Italian digital agency, the research amplifies the scope of the current discussions on national e-Government trajectories, providing evidence for the interrelated dynamics between policy outcomes, implementation mechanisms and administrative landscape. The article shows that the discontinuity of Italy’s Digital Agenda is attributable to the merry-go-round nature of governments with divergent views of modernization – resulting in the digital agency’s multiple, even conflicting mandates – and to the misalignment of the ‘original agency model’ with the embedded culture of the public machinery. The article provides illustration of these arguments from the historical institutionalist perspective and maintains that insights into these phenomena are essential for contextualizing and understanding ICT policies. 相似文献
136.
Lorella Paparo Maria Antonia Maglio Maddalena Cortese Cristina Bruno Mario Capasso Erika Punzo Veronica Ferrucci Vito Alessandro Lasorsa Maurizio Viscardi Giovanna Fusco Pellegrino Cerino Alessia Romano Riccardo Troncone Massimo Zollo 《Molecules (Basel, Switzerland)》2022,27(3)
Butyrate is a major gut microbiome metabolite that regulates several defense mechanisms against infectious diseases. Alterations in the gut microbiome, leading to reduced butyrate production, have been reported in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A new butyrate releaser, useful for all the known applications of butyrate, presenting physiochemical characteristics suitable for easy oral administration, (N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA), has been recently developed. We investigated the protective action of FBA against SARS-CoV-2 infection in the human small intestine and enterocytes. Relevant aspects of SARS-CoV-2 infection were assessed: infectivity, host functional receptor angiotensin-converting enzyme-2 (ACE2), transmembrane protease serine 2 (TMPRSS2), neuropilin-1 (NRP1), pro-inflammatory cytokines expression, genes involved in the antiviral response and the activation of Nf-kB nuclear factor (erythroid-derived 2-like) 2 (Nfr2) pathways. We found that FBA positively modulates the crucial aspects of the infection in small intestinal biopsies and human enterocytes, reducing the expression of ACE2, TMPRSS2 and NRP1, pro-inflammatory cytokines interleukin (IL)-15, monocyte chemoattractant protein-1 (MCP-1) and TNF-α, and regulating several genes involved in antiviral pathways. FBA was also able to reduce the number of SARS-CoV-2-infected cells, and ACE2, TMPRSS2 and NRP1 expression. Lastly, through the inhibition of Nf-kB and the up-regulation of Nfr2, it was also able to reduce the expression of pro-inflammatory cytokines IL-15, MCP-1 and TNF-α in human enterocytes. The new butyrate releaser, FBA, exerts a preventive action against SARS-CoV-2 infection. It could be considered as an innovative strategy to limit COVID-19. 相似文献
137.
Naouel Admane Giuseppe Cavallo Chahinez Hadjila Maria Maddalena Cavalluzzi Natalie Paola Rotondo Antonio Salerno Joseph Cannillo Graziana Difonzo Francesco Caponio Antonio Ippolito Giovanni Lentini Simona Marianna Sanzani 《Molecules (Basel, Switzerland)》2023,28(1)
The urgent need to increase the sustainability of crop production has pushed the agricultural sector towards the use of biostimulants based on natural products. The current work aimed to determine whether the preharvest application of two commercial formulations, based on a Fabaceae enzymatic hydrolysate or a blend of nitrogen sources including fulvic acids, and two lab-made aqueous extracts from Moringa oleifera leaves (MLEs), could improve yield, quality, and storability of lettuce grown in a hydroponic system, as compared to an untreated control. Lettuce plants treated with the MLEs showed significantly improved quality parameters (leaf number, area, and color), total phenolic content and antioxidant activity, and resistance against the fungal pathogen Botrytis cinerea, comparable to that obtained with commercial formulates, particularly those based on the protein hydrolysate. A difference between the M. oleifera extracts was observed, probably due to the different compositions. Although further large-scale trials are needed, the tested MLEs seem a promising safe and effective preharvest means to improve lettuce agronomic and quality parameters and decrease susceptibility to rots. 相似文献
138.
Sørensen HA Sperotto MM Petersen M Keşmir C Radzikowski L Jacobsen S Søndergaard I 《Rapid communications in mass spectrometry : RCM》2002,16(12):1232-1237
The performance of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry with neural networks in wheat variety classification is further evaluated.1 Two principal issues were studied: (a) the number of varieties that could be classified correctly; and (b) various means of pre-processing mass spectrometric data. The number of wheat varieties tested was increased from 10 to 30. The main pre-processing method investigated was based on Gaussian smoothing of the spectra, but other methods based on normalisation procedures and multiplicative scatter correction of data were also used. With the final method, it was possible to classify 30 wheat varieties with 87% correctly classified mass spectra and a correlation coefficient of 0.90. 相似文献
139.
Weighardt F Barbati C Paoletti C Querci M Kay S De Beuckeleer M Van den Eede G 《Journal of AOAC International》2004,87(6):1342-1355
In Europe, a growing interest for reliable techniques for the quantification of genetically modified component(s) of food matrixes is arising from the need to comply with the European legislative framework on novel food products. Real-time polymerase chain reaction (PCR) is currently the most powerful technique for the quantification of specific nucleic acid sequences. Several real-time PCR methodologies based on different molecular principles have been developed for this purpose. The most frequently used approach in the field of genetically modified organism (GMO) quantification in food or feed samples is based on the 5'-3'-exonuclease activity of Taq DNA polymerase on specific degradation probes (TaqMan principle). A novel approach was developed for the establishment of a TaqMan quantification system assessing GMO contents around the 1% threshold stipulated under European Union (EU) legislation for the labeling of food products. The Zea mays T25 elite event was chosen as a model for the development of the novel GMO quantification approach. The most innovative aspect of the system is represented by the use of sequences cloned in plasmids as reference standards. In the field of GMO quantification, plasmids are an easy to use, cheap, and reliable alternative to Certified Reference Materials (CRMs), which are only available for a few of the GMOs authorized in Europe, have a relatively high production cost, and require further processing to be suitable for analysis. Strengths and weaknesses of the use of novel plasmid-based standards are addressed in detail. In addition, the quantification system was designed to avoid the use of a reference gene (e.g., a single copy, species-specific gene) as normalizer, i.e., to perform a GMO quantification based on an absolute instead of a relative measurement. In fact, experimental evidences show that the use of reference genes adds variability to the measurement system because a second independent real-time PCR-based measurement must be performed. Moreover, for some reference genes no sufficient information on copy number in and among genomes of different lines is available, making adequate quantification difficult. Once developed, the method was subsequently validated according to IUPAC and ISO 5725 guidelines. Thirteen laboratories from 8 EU countries participated in the trial. Eleven laboratories provided results complying with the predefined study requirements. Repeatability (RSDr) values ranged from 8.7 to 15.9%, with a mean value of 12%. Reproducibility (RSDR) values ranged from 16.3 to 25.5%, with a mean value of 21%. Following Codex Alimentarius Committee guidelines, both the limits of detection and quantitation were determined to be <0.1%. 相似文献
140.
Maddalena Donati Andrea Mondin Zheng Chen Fabricio Mendes Miranda Baraquizio Braga do Nascimento Jr Giulia Schirato 《Natural product research》2015,29(10):939-946
The essential oils (EOs) from the Brazilian species Croton zehntneri, Pterodon emarginatus and Schinopsis brasiliensis were examined for their chemical constituents, and antioxidant and antimicrobial activities. The composition of EOs was determined by using gas chromatography coupled with mass spectrometry analysis, while the antioxidant activity was evaluated through the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. Furthermore, the antimicrobial activity was investigated against Escherichia coli and Pseudomonas aeruginosa (both Gram-negative), Staphylococcus aureus (Gram-positive) and Candida parapsilosis (fungus). The main components of C. zehntneri, P. emarginatus and S. brasiliensis were identified as estragole, trans-anethole, β-caryophyllene and myrcene. Among the EOs, P. emarginatus showed the highest antioxidant activity, with an IC50 of 7.36 mg/mL and a Trolox equivalent antioxidant capacity of 3748 μmol/g determined by DPPH and ORAC assays, respectively. All EOs showed low activities against the bacterial strains tested, whereas the C. zehntneri oil and its main constituent estragole exhibited an appreciable antifungal activity against C. parapsilosis. 相似文献