Room-Temperature Inter-Dot Coherent Dynamics in Multilayer Quantum Dot Materials

The full blossoming of quantum technologies requires the availability of easy-to-prepare materials where quantum coherences can be effectively initiated, controlled, and exploited, preferably at ambient conditions. Solid-state multilayers of colloidally grown quantum dots (QDs) are highly promising for this task because of the possibility of assembling networks of electronically coupled QDs through the modulation of sizes, inter-dot linkers, and distances. To usefully probe coherence in these materials, the dynamical characterization of their collective quantum mechanically coupled states is needed. Here, we explore by two-dimensional electronic spectroscopy the coherent dynamics of solid-state multilayers of electronically coupled colloidally grown CdSe QDs and complement it by detailed computations. The time evolution of a coherent superposition of states delocalized over more than one QD was captured at ambient conditions. We thus provide important evidence for inter-dot coherences in such solid-state materials, opening up new avenues for the effective application of these materials in quantum technologies

Transfer of Electronic Commerce to Small Firms. The Role of Innovation Centres in the E.U

Despite the potential ascribed to Electronic Commerce (Ecom), the diffusion among SMEs is still low. Electronic transactions require appropriate solutions for the automation of business procedures and the management of electronic markets, and this requires highly specialised knowledge that SMEs may find it difficult to acquire or apply. To facilitate the use of Ecom by SMEs, several projects have been promoted by local innovation centres, that in many European countries have often played a key role in the transfer of tech-nology. However, the success of such Ecom projects are controversial. After characterising Ecom as innovation and the conditions for its effective transfer, the paper analyses the role of local innovation centres in Ecom transfer to SMEs by means of empirical case-study research in Italy and UK

Innovation centres and transfer of technology to small firms: the case of electronic commerce in the E.U

Despite the great potential ascribed to Internet Electronic Commerce (Ecom), the diffusion among SMEs is still low. The execution of electronic transactions requires appropriate solutions for the automation of business procedures and for the management of electronic markets, and this requires highly specialised knowledge that SMEs may find it difficult to acquire or apply. In order to facilitate the use of Ecom by, SMEs, several projects have been promoted by various institutions. The paper analyses the initiatives of local innovation centres that in many European countries have often played a central role in the transfer of technology to SMEs. However, their success in Ecom is controversial, due to the specific nature of Ecom. After characterising Ecom as innovation and the conditions for its effective transfer, the paper analyses the potential of innovation centres. The preliminary results of empirical case-study research in Italy and the UK are then illustrated

Botrytis cinerea counteracts a grapevine chitinase by reducing its enzymatic activity and increasing the expression of the chitin synthase genes

Chitin represents a main component of cell wall in filamentous fungi. In Botrytis cinerea the synthesis of this polymer involves a set of chitin synthases (Chs) grouped in seven classes. The relevance of Chs enzymes is demonstrated by reduction in growth and pathogenicity of B. cinerea Chs disrupted mutants. During plant infection, chitin apposition to fungal cell wall is counteracted by host chitinases. Chitin synthesis and chitin degradation are, therefore, two opposite processes that can affect the infection outcome. We observed that the protease activity secreted by B. cinerea strain B0510 partially degrades a class IV chitinase of Vitis vinifera by cleaving the chitin binding domain (CBD) of this enzyme, which favors the attachment of chitinase to the fungal chitin substrate. In fact, the removal of the CBD reduces the chitinase activity by about 50%. We hypothesized that the intact and the cleaved chitinase can differently affect B. cinerea chitin synthesis. To verify this aspect we have analyzed by quantitative PCR the expression of Chs genes following B. cinerea treatment with intact and cleaved chitinase. We observed that the cleaved chitinase regulates positively the transcription of some Chs genes. These results show evidence that B. cinerea counteracts the host chitinase by reducing the activity of this enzyme and increasing the expression of chitin synthase genes

Botrytis cinerea cleaves a grapevine chitinase decreasing its enzymatic activity and impairing the detrimental effect on fungal growth

Chitin represents the main fibrillary component of the fungal cell wall. During plant infection, chitin apposition is counteracted by host chitinases. A chitinase class IV is constitutively contained in grapevine berries and it is expressed in leaves following Botrytis cinerea infection. Early, during fungal growth, the fungus proteolytically remove the chitin-binding domain (CBD). The chitinase without the CBD shows a reduction of activity by about 50% and louses the detrimental effects on conidia germination and fungal growth. Protease inhibition assays provided evidence that metalloprotease activity is involved in the chitinase cleavage. To ascertain whether the native and cleaved chitinase can differently affect the expression of genes involved in B. cinerea cell wall modeling, we analyzed by qPCR the expression of five fungal chitin synthase (Chs) and four chitin deacetylase (Cda) genes. Only one Chs gene decreased its expression in presence of the native chitinase. In conclusion, the removal of the CBD by B. cinerea proteases appears as a mechanism preserving fungal growth from plant chitinase activity. Further experiments will better clarify the type of B. cinerea protease activity capable to disarm the plant chitinases

Peptaibols as naturally-based fungicides against grapevine pathogens

Fungi belonging to the genus Trichoderma are widespread and have been used successfully in protection against many crop pathogens. Among the secondary metabolites secreted against dangerous plant pathogens, Trichoderma species produce peptaibols, a peculiar family of peptides that significantly contribute to their attack arsenal against other microorganisms. Such secondary metabolites are known for their plant-protection properties: they (i) possess antimicrobial activity, (ii) act as stimulants of plant defences and growth (iii) elicit plant production of volatiles to attract natural enemies of herbivorous insects. Moreover, peptides are ecofriendly compounds that can be degraded by enzymes to nontoxic amino acids. We present our progress towards the exploitation of analogs of the peptaibols family as fungicides. These peptides have been screened against Plasmopara viticola and Botrytis cinerea, two of the most important grapevine pathogens in the temperate regions including Italy. We found that treatments with selected peptaibols on grapevine leaves inhibit sporangia production by the downy mildew pathogen P. viticola and decrease the incidence of leaf rot by the grey mould fungus B. cinerea. Experiments are in progress to assay the effectiveness of peptaibols against Colletotrichum gleosporioides and C. acutatum, two of the most dangerous ripe rot fungi in sub-tropical climate including the south regions of Brazil. Additional experiments showed a low level of toxicity against the yeast Saccharomyces cerevisiae. Such compounds can match the demand of environmental safe fungicides and circumvent the unreliable effectiveness of antagonistic microorganisms used as biological control agents in open field

Peptides obtained by targeted modifications of a natural Trichoderma peptaibol protect plants from grey mold disease and downy mildew

Fungal species belonging to the Trichoderma genus are commonly used as biocontrol agents against several crop pathogens. Among their secondary metabolites, peptaibols are helical, antimicrobial peptides structurally stable even under extreme pH and temperature conditions. The promise of peptaibols as agrochemicals is however hampered by poor water solubility, which inhibits efficient delivery for practical use in crop protection. Using a versatile synthetic strategy, based on green chemistry procedures, we produced water-soluble peptaibol analogs of the 11-mer lipopeptaibol trichogin GA IV, naturally produced by Trichoderma longibrachiatum. These newly synthesized peptides were tested against the important plant pathogens Botrytis cinerea and Plasmopara viticola. Compared to native trichogin, which was inactive against the tested pathogens, some peptide analogs resulted particularly effective at low micromolar concentrations against both pathogens, while others were effective only against one of them. The most effective peptides significantly reduced disease symptoms by P. viticola on grapevine leaves and by B. cinerea on grapevine leaves, ripe grape berries and tomato leaves. Our results suggest that trichogin-derived peptides do not prime plant defenses but protect plant tissues by inhibiting spore germination on the host surface. An in-depth conformational analysis featuring a 3D-structure-activity relationship study indicated that the relative spatial position of cationic residues in the sequence is crucial for increasing peptide fungicidal activity. Besides, effective peptides maintain the right-handed helical structure even in the presence of the pathogen. Further studies will help clarify the mode of action of these antimicrobial peptides

Pattern of metastasis and outcome in patients with breast cancer

There is growing evidence about differences in metastatic spread among breast cancer (BC) biologic subtypes (BS). Aim of this study was to analyze the pattern of metastasization according to BS and to explore the corresponding prognosis. A series of 544 consecutive patients receiving anticancer therapy for metastatic BC from 2004 to 2013, was analyzed. BS were defined by immunohistochemistry according to St Gallen 2013 criteria. Association between BS and the different distant localizations was analyzed. Prognosis was described in terms of overall survival (OS), progression free survival (PFS) and post progression survival (PPS). Results were reported taking luminal A BC as reference. Triple negative BC showed a higher tropism for lung (OR 4.30 95% CI 1.41-13.1), while non luminal HER2 subtype was associated with a higher rate of liver metastases (OR 3.61 95% CI 1.36-9.58). All subtypes were associated with a lower risk of bone-only localization. Central nervous system (CNS) involvement was more common in HER2 positive BC (OR 6.3, 95% CI 1.08-36.66). Liver, lung and CNS involvement influenced negatively OS (HR 1.64, 95% CI 1.29-2.07; HR 1.49, 95% CI 1.18-1.90; HR 2.891, 95% CI 1.85-4.51, respectively) and PFS (HR 1.39, 95% CI 1.13-1.71; HR 1.26, 95% CI 1.02-1.55; HR 1.75, 95% CI 1.12-2.71, respectively). Multivariate analysis confirmed liver involvement as independent predictor of worse OS (HR 1.64, 95% CI 1.15-2.34). Stratification by metastatic pattern showed significant differences in terms of PPS but not in terms of PFS. The study suggests that BS may be characterized by typical patterns of metastatic spread and have different impact on clinical outcome

FEASIBILITY STUDY OF A WEB APPLICATION FOR SELF-REPORT OF ANTICANCER TREATMENT TOXICITIES

Collection of collateral effects related to toxicities suffered by patients being exposed to anticancer treatments is of crucial importance in clinical practice but also in oncological research. The present paper describes a web application called PaTOS for self-report of anticancer therapy toxicities, and its evaluation in a preliminary interface analysis and then in a feasibility study

Peptaibol analogs as new effective fungicides against Botrytis cinerea

In the last decades the search for new effective and sustainable fungicides has gained much importance in the European political agenda. The well-known biocontrol agent Trichoderma spp. produces short hydrophobic non-ribosomal peptides, named peptaibols, with antibiotic properties given by their ability to permeabilize lipid bilayers such as the cell membrane. Specifically, the peptaibol trichogin produced by T. longibrachiatum, was used as a model to synthesize several water-soluble analogs (De Zotti et al., 2020 International Journal of Molecular Sciences, 21, 7521). These analogs present one or more substitutions of the glycine residues, which improve their water-solubility while maintaining their thermal and chemical stability. The aim of this study was to assess the fungicidal activity of trichogin analogs against Botrytis cinerea. With an in vitro screening, four peptides were identified as effective in inhibiting conidia germination at 15 µM concentration and the most effective peptide displayed a Minimal Inhibitory Concentration of 1-5 µM. A microscopy analysis confirmed conidia cell death at 15 µM. This peptide was used in further experiments to assess its efficacy in controlling B. cinerea infection on different plant tissues. On bean leaves, this peptide determined a significant reduction of disease symptoms (higher than 95%) at 50 µM, being effective also at 15 µM (75% symptom reduction). Treatment of grapevine leaves and berries at 50 µM showed a significant reduction of disease symptoms of about 70% and 45%, respectively. Several analogs of this peptide, differing in sequence length or C-terminus to decrease synthesis costs, have also been produced and tested. Both changes did not affect peptide efficacy either in vitro and against infection on bean leaves. These results show the potential given by small structural modifications of natural secondary metabolites. Ongoing trials are now focusing on the combination of peptides and other natural antimicrobial compounds, with the aim to identify any synergistic effect against B. cinerea. Synergy would allow to reduce the fungicide dosage with many benefits, including the reduction of treatment cost, a better toxicity profile and a minimized probability of resistance development