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12 figures, 2 tables.-- Supplementary information available.-- © 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/, The catalytic performance of SWCNT was notably improved in the oxidative dehydrogenation of ethylbenzene (EB) to styrene (ST) upon a double-function purification in one step of the raw SWCNT. This consists of lowering the MeOx concentration and generating surface C=O groups after processing it in nitric acid at controlled conditions, while preserving the structure. The textural improvement was ascribed to the cutting of the tubes/bundles by oxidation and to MeOx removal itself (dilution effect). Both EB conversion and ST selectivity increased with a parallel lowering of the undesired COx selectivity. The conversion was interpreted by the enhancement of the intrinsic properties (i.e., more surface ketonic groups) but also to the higher load of SWCNT in the bed upon purification; both factors contribute to a higher number of active sites (C=O) in the bed for styrene formation. The most purified catalyst underperformed in conversion once the purification altered the SWCNT structure notably. Thus, preserving the structure is an important condition to achieve high conversion and yield. The better selectivity was explained in two ways; more styrene-forming sites (C=O) or less COx-forming sites (uncoated MeOx) in the bed, or both. The styrene yield per catalyst volume was improved by an average of ca. 240 % in comparison to the non-purified SWCNT. Deactivation is critical in maximizing the purification effect on the intrinsic and volumetric yields. In practical terms, the purification method proved to enhance the reaction; the selectivity towards the unwanted COx was significantly lowered with a gain towards styrene, achieving comparable selectivity values as in the conventional process, but operated at much lower temperature., This work was supported by the Netherlands Organization for Scientific Research (NWO), under the Vidi grant no. 10284 (www.nwo.nl/en/projects/10284), carried out at Groningen University and completed by I.M.C. at La Laguna University. J.H. Marsman and L. Falco are thanked for assisting in the commissioning of the gas analysis system. A.M. acknowledges the Spanish Ministry of Science and Innovation (RYC2018-024561-I) and to the regional government of Aragon (DGA E13_20R). Additional funding was received from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3). E.G.B. thanks financial support from Gobierno de Aragón (Grupo Reconocido DGA T03_20R).

Background Transmural remission in Crohn’s disease (CD) has been associated with improved long-term clinical outcomes including reduced hospitalization, surgery, escalation of treatment, and a decrease in clinical relapse over endoscopic remission alone. Albeit transmural remission rate (TRR) in CD patients treated with anti-TNF drugs in first line has been well explored, data on TRR using vedolizumab (VDZ) or ustekinumab (UST) as second-line therapy for CD are still scarce. The aim of this study was to evaluate the TRR in CD patients in maintenance treatment, comparing adalimumab (ADA) in first line with VDZ/UST in second line. Methods From 2018 to 2021 we performed a real world observational longitudinal study evaluating the TRR in all consecutive CD patients in a 2-years maintenance treatment with ADA in first line compared with those treated by VDZ or UST in second line. HBI, fecal calprotectin (FC), SES-CD, and bowel wall thickness (BWT) at ultrasound were analyzed in all patients at the baseline (T0) and after 2 years of maintenance treatment (T1). Clinical remission was defined when HBI was Results One hundred and forty-one CD patients (78 ADA, 31 VDZ, 32 UST) were included in the study. At T1, transmural remission rate was recorded in 39.7% of CD patients treated in first line with ADA, and in 22.5% and 18.7% for VDZ and UST, respectively, in second line (ADA vs VDZ/UST: p Conclusion Our findings showed that in CD patients in maintenance treatment with biologics, ADA in first line showed a higher TRR compared with VDZ/UST in second line. Moreover, VDZ and UST showed similar TRR and other outcomes when used in second line.

Background Partial enteral nutrition (PEN) is a consolidated treatment in children with active Crohn’s disease (CD). However, the benefit of PEN is not well-established for adults with CD. Based on the assumption that diet could aid in treating active disease, we aimed to assess the effectiveness of PEN in combination with biological therapy on transmural response/remission and selected clinical outcomes in adults with CD who lost response to biologics Methods We performed a single-centre retrospective observational study by including patients who received PEN due to loss of response to biologics. The primary endpoint was the rate of transmural response/remission at 6 months. We defined transmural remission as a bowel wall thickness ≤3 mm, while transmural response as a decrease in BWT≥25%. Secondary endpoints included clinical remission, defined as Harvey Bradshaw Index Results A total of 42 patients,25 males (59,5%) with mean age of 36,1 ±15,6 yo and a mean duration of disease of 138,0 ±113,1 months were enrolled [Table 1]. Overall, 14 patients completed PEN at 8 weeks, with a rate of adherence of 33,3%. Whilst 16(38.1%) patients stopped the treatment for intolerance and maintained only biological therapy and 12(28.6%) underwent surgery before 6 months follow-up.At 6 months, patients treated with PEN in combination with biologic had a transmural response of 64,9% compared to 25% treated only with biologics (p=0.03). In both groups, no patients achieved transmural remission. Nevertheless, clinical remission was obtained in 9 (64,3%) patients treated with PEN + biologic compared to 4 (25%) with biologic (p=0.03). Overall,3 patients (18.7%) underwent surgery, all of them were intolerant to PEN. Patients who interrupted PEN and maintained biologics had a higher rate 56,2% of dose escalation/interval and 68,7% changed therapy at six months compared to 7,1% and 14,2% respectively treated with PEN+biologic (p Conclusion For patients who lost response to biological therapy, the combination with PEN was associated with transmural response and clinical remission. Multiple failures to biologics were associated with adherence to PEN. Hence, the use of PEN dietary should be considered in difficult-to-treat patients

The synthesis of anatase TiO

Propylene is a very essential building block in the petrochemical industry. There is a fast growing in its demand that is steadily expanding its market. Fluid catalytic cracking units is the second largest propylene source for petrochemical application. FCC units are primarily used in the production of gasoline. However, refiners have taken advantage with the aim of producing and recovering large amounts of propylene from their Fluid catalytic cracking unit by raising the severity of reaction through riser temperature, installation of a propylene recovery unit and addition of a catalyst that is shape selectivity. ZSM-5 is nowadays used as a very efficient fluid catalytic cracking additive for increasing light olefins production i.e. propylene. This short review will be exclusively focused on ZSM-5-containing additives and look at the main strategies used in the design and modifications of ZSM-5 catalysts to increase the propylene production in the FCC units. The review will highlight the most important and the recent modification methods used in enhancing ZSM-5 performance in the FCC process to maximize the yield of light olefins in general, and in particular that of propylene. These methods include particle size and acidity modification, phosphorus treatment, mesoporous/hierarchical structure creation, incorporation alkali metals and some selected transition metals and introduction of rare-earth metal.

Archaeological high-tin copper-based artefacts, dated back to VIII and IV centuries BC and recently discovered in the Italic necropolises of ancient Abruzzo (Central Italy), were investigated in order to determine the micro-chemical and micro-structural nature of the corrosion products and the chemical composition and metallurgical features of the alloys. The Cu-based artefacts were defensive weapons mainly as bronze belts and pectoral disc armours with engraved decorations. A rather detailed picture of the chemical composition, structural and morphological characteristics of such Cu-based artefacts was provided by combining different techniques as scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), optical microscopy (OM) and X-ray diffraction (XRD) analysis. The results, as a whole, evidence that some artefacts were manufactured by casting and shaping uncommon high-tin bronze alloys thus conferring an attractive silver-like appearance. The manufacturing process was based on tailored multiple hot hammering, carefully carried out at about 700 °C to shape the high-tin alloys in the form of sheets avoiding breaking. The mechanical work was followed by an annealing treatment, polishing and final decorative finishing. Furthermore, our investigation on the corrosion process, suggest that it is a mixture of rather complex phenomena leading to the degradation of the main alloying elements which give rise to mineral alteration products in the form of complex structures. These latter contain SnO2 (cassiterite), cuprous oxide, copper carbonates (azurite and malachite) and, in particular, chlorine-based compounds like nantokite and atacamite and its polymorphs, which have heavy detrimental effects, their presence being considered a symptom of the destructive “bronze disease” degradation phenomenon. Moreover, it was found an unusual presence of re-deposited Cu inclusions to be likely related to long-term corrosion processes and to a low oxygen availability in the burial environment. All these findings show, as a whole, that there is a strict relationship between alloy elements, metallurgical features, burial soil conditions and chemical and structural features of the corrosion products. This paper highlights also as the combined use of different techniques as SEM-EDS, ATR-FTIR, XPS, XRD and OM can be one of the possible successfully way to study the corrosion products of archaeological copper-based artefacts, thus helping to choose the more appropriate strategies for the long-lasting conservation of archaeological bronze artworks, in most cases so valuable for the cultural heritage.

The removal of the commonly used herbicides is essential for environmental remediation. In this study, mesoporous TiO2 photocatalysts modified with PtO were synthetized by the template-assisted scheme to develop highly effective materials for the elimination of Imazapyr herbicide under visible-light preservation. The effect of the PtO loading was investigated, and the xPtO-TiO2 materials were deeply considered by N2 physisorption, XRD, HRTEM, FTIR, DRS UV-Vis, Raman, XPS, PL and photocurrent measurements. Total Imazapyr photodegradation was archived on mesoporous TiO2 photocatalysts loaded with 0.6 and 0.8 wt% of PtO. The optimized xPtO-TiO2 photocatalyst degrades the Imazapyr under solar light more efficiently than the pure TiO2 and the commercial Degussa P25 (photoefficiency of 35%, 1%, and 0.5%, respectively). The improvement in the photoefficiency of the xPtO-TiO2 photocatalysts respect to the pure TiO2 was associated to the cooperative effect between PtO and TiO2 nanoparticles leading to a lessening in the energy gap and lower recombination of excited electron-hole pairs. The optimized 0.6PtO-TiO2 photocatalyst demonstrated to be stable and recyclable after up to five consecutive photocatalytic runs. Therefore, it can be a potential candidate for the significant mineralization of Imazapyr herbicide under solar light irradiation.

Background Coronary artery ectasia (CAE) is a relatively frequent finding in patient with ST-elevation myocardial infarction (STEMI) who undergo emergent coronary angiography. However, the long-term outcome of STEMI patients with CAE as compared to Non-CAE has been poorly investigated. Purpose To compare the baseline features and outcome of patients with and without CAE in the clinical setting of STEMI. Methods All patients with STEMI who underwent emergent coronary angiography from January 2012 to December 2017 at our Institution were retrospectively enrolled. Baseline demographic, clinical, instrumental, angiographic and percutaneous coronary intervention (PCI) findings were collected for patients with and without CAE. The study outcome measures were recurrent myocardial infarction (MI) and all-cause death. The propensity score weighting (PSW) technique was used to take into account for potential selection bias in treatment assignment between CAE and Non-CAE groups. Results The study included 534 patients with STEMI (mean age 62.9±12.0 years), 154 were CAE and 380 Non-CAE. The two groups were significantly different in terms of sex (90.9% in CAE vs 72,6% in Non-CAE, p The survival free from recurrent MI was lower, although not statistically significant, in CAE vs. Non-CAE patients (3.1/100 person/years vs. 4.8/100 person/years; Log-Rank = 0.068). After PSW, an optimal balance was obtained as demonstrated by a standardized mean difference Conclusions Patient with STEMI and angiographic evidence of CAE have a different clinical profile compared to Non-CAE. In this analysis focused on STEMI patients, CAE was associated with a higher risk of recurrent MI at long-term follow-up. Funding Acknowledgement Type of funding source: None

Although preschoolers have strong expectations about the pedagogical nature of pointing gestures (Csibra & Gergely, 2006), more recent work has shown that preschoolers prefer to use informants’ spoken language, not their pointing gestures, to make judgments about their reliability (Palmquist & Jaswal, 2015). Here, we explored children’s inferences about pointers using a standard selective trust paradigm. Specifically, we asked whether 4- and 5-year-olds generalize reliability across communicative domains (from pointing ability to speaking ability). We found that children preferred to make generalizations about pointers’ reliability when they had conveyed semantic, but not episodic, knowledge. Individual differences in theory of mind also predicted children’s willingness to make generalizations about pointers’ reliability. Both sets of results suggest that multiple factors (i.e., the type of knowledge an informant shares and individual differences in children’s cognitive development) affect whether...

Ancient silver-based alloys objects are of a great interest because they were world-wide used to produce high value works of art and precious items as jewels and ornaments with a relevant artistic, religious or historical value. Silver-based alloys were also largely used everyday as monetary currency and form of saving playing a relevant role for the development and growth of the economy. By means of the combined use of complementary surface analytical techniques such as scanning electron microscopy coupled with energy dispersive spectrometry (SEM + EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and optical microscopy (OM) we have investigated the micro- and nano-chemical nature of the products of corrosion naturally formed on archaeological silver-based Roman objects characterised by different burial conditions. The results allow the identification of different corrosion products formed during the long interaction between the elements constituting the alloy, i.e. Ag and Cu, and degradation agents present in the surrounding environment. The results of the integrated analytical methodologies highlight the role of chlorine, that is always present in the patina as chloroargyrite (AgCl, also known as cerargyrite or horn silver) and also in some cases of bromine which forms bromargyrite (AgBr) or bromian-chloroargyrite [Ag(Br,Cl)] as dominant corrosion products. The unusual presence of Br in the silver patina reflects the peculiar environmental chemistry suffered by the buried object likely due to the presence of degrading organic matter under aerobic conditions. Furthermore, the results reveal that chlorine often preferentially corrodes the numerous local copper enrichments randomly dispersed in the silver host matrix inducing the formation of harmful copper-chlorine compounds including Cu2Cl(OH)(3) (atacamite and its polymorphs) and likely CuCl (nantokite) generally related to the copper cyclic corrosion called by conservators "bronze disease". Finally, different corrosion patterns have been observed with the outermost layers often enriched by soil elements as S, Ca, Al, Si and Fe thus confirming the strong interaction of the alloys elements with the burial soil components. (C) 2017 Elsevier B.V. All rights reserved.

A detailed XPS investigation, supported by XRD analysis, was performed on Co-Zn-Mn oxide-based spinels as a function of cobalt concentration and calcination temperature (723 and 973 K). Results revealed for the first time that a recarbonation occurred under ambient conditions but only for the Co-containing materials calcined at 973 K. Indeed, such effect was not observed for the homologous preparations at 723 K. This evidence was quite surprising because the solids calcined at 973 K, for which a sintering occurred as reflected by the low surface areas, were supposed to be almost inert under ambient conditions. Such an intriguing recarbonation chemistry, leading even to a bulky rhodochrosite-like (MnCO3) phase in the cobalt most enriched samples, arises from the combined effect of the calcination treatment at high temperature and the presence of cobalt ions. The spinels calcined at higher temperature are characterized by a high surface defectivity, due to anionic vacancies produced by a partial self-reduction of a fraction of Mn3+ ions that occurs only at 973 K but not at 723 K. Consequently, the presence of anionic vacancies and the incomplete coordination of the outermost layers promoted a higher reactivity of the solids calcined at 973 K with CO2 and moisture from ambient air. However, a carbonate phase was absent in the sample at 973 K with no cobalt. This suggests that the presence of cobalt is another crucial factor for the recarbonation process to take place. Cobalt ions appear to play a catalytic role. An attempt is made to provide a reasonable explanation of this intriguing recarbonation chemistry, trying to shed some more light on the rather complex chemistry behind the attack of moisture and CO2 to oxide solid surfaces. These results, as a whole, may provide new insight on phenomena observed in the case of some Mn-based catalysts, as the severe deactivation by traces of moisture occurring in hopcalite during CO oxidation at RT. They may also give an additional perspective to environmental processes that involves the interaction of moisture and CO2 with the surface of Mn-based solids or other materials as environmental interfaces.

Naturally grown patinas are typically detected onto the surface of modern copper-based artefacts and strictly affect their surface reactivity and appearance. The production of representative patinas is a key issues in order to obtain model systems which can be used for the development and validation of appropriate conservation materials and methods. In this study, we have prepared different artificial representative patinas by using a quaternary Cu-Sn-Zn-Pb alloy with chemical composition and metallurgical features similar to those of valuable modern works of art. In order to produce degradation products usually observed onto their surface, chloride and sulphate species were used to induce corrosion processes. Different patinas were produced by changing the nature of corrosive species and the set-up for the accelerated degradation. The composition and structural properties of the patinas were investigated by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy. The results allow to identify degradation products and to distinguish copper hydroxychloride polymorphs and copper hydroxysulphates with similar structure. Our findings show that patina composition can be tailored by modifying the degradation procedure and patinas representative of modern artefacts made of quaternary Cu-Sn-Zn-Pb alloy can be obtained.

The corrosion products naturally formed on archaeological Cu-based artefacts during their long-term exposure to seawater have been investigated in details by means of X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectrometry (SEM + EDS), optical microscopy (OM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential thermal analysis-thermogravimetry (DTA-TG), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The bronze artefacts include fragments of valuable statues and objects that were retrieved some decades ago from different seabeds along the Italian coast of the Mediterranean basin including the so called “Punta del Serrone” area (Apulia), the Sicilian channel (Sicily) and the Arburese coast (Sardinia). Our findings show that the alloy matrix is often heavily corroded also in the bulk and reveal the dangerous presence of chlorine from seawater as main dangerous corrosive agent. Chlorine is present as copper nantokite (CuCl) in the inner layers of the patina and is potentially inducing with oxygen and moisture the cyclic and often relentless copper degradation phenomenon commonly called “bronze disease”. The most common corrosion products are also lead carbonate (cerussite, PbCO3) and aragonite (CaCO3), likely related to the large abundance of CO2 in the seawater where is assimilated much more than in fresh water. Furthermore, the results reveal that other environmental elements contributing to the composition of the patina are sulphur, magnesium and phosphorous thus giving rise to a patina with a chemically and structurally complex structure. The results reveal also the contribution of bio-organism to the formation of the patina as supported by the presence of vanadium and copper sulphides. These information allow, as a whole, to propose a tentative correlation between the patina’s nature, the chemical composition and metallurgical features of the alloys and the marine environment where the objects lived for about two thousands years. From a conservation point of view, the findings reported in this work can provide some insights useful to tailor more efficient conservation strategies with the purpose to ensure a long-term chemical-physical stability to the bronze artefacts.

Correction for ‘High enhancement of the hydrolysis rate of cellulose after pretreatment with inorganic salt hydrates’ by Marta Lara-Serrano et al., Green Chem., 2020, 22, 3860–3866, DOI: 10.1039/D0GC01066A.

N-Doped graphene (N-G) has been covalently functionalized on the nitrogen with a C60 derivative. Photophysical studies of the new hybrid and electron pooling experiments reveal the utility of this material in photocatalytic energy harvesting applications., N-Doped graphene (N-G) was chemically functionalized by N-alkylation with the well-known electron acceptor C60. The degree of functionalization and the key structural features of the N-G/C60 hybrid were systematically investigated by a number of techniques including thermogravimetric analysis, X-ray photoelectron and Raman spectroscopies and transmission electron and atomic force microscopies. Absorption and electrochemical studies revealed interactions between the N-G and C60 while the fluorescence of C60 within the hybrid was found to be fully quenched. Evidence for the occurrence of excited state charge transfer from the singlet excited C60 to N-G in the hybrid was obtained from femtosecond transient absorption studies covering the visible–near-IR regions. Electron-pooling experiments performed in the presence of a sacrificial electron donor and a second electron acceptor, methyl viologen, revealed the accumulation of the one-electron reduced product of methyl viologen upon continuous irradiation of the N-G/C60 nanohybrid, thus revealing the utility of this material in photocatalytic energy harvesting applications.

Gilded brooches dating back to 16th-17th centuries CE were investigated by means of integrated and complementary analytical techniques such as high spatial resolution field emission scanning electron microscopy coupled with energy dispersive X-ray spectrometry (FE-SEM+EDS), time of flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and optical microscopy (OM). The results reveal in detail the surface and subsurface morphology and the chemical features of the micrometric decorative Au layer that has been deposited by means of the so-called fire-gilding technique based on the use of an amalgam. Moreover, the results allow to recognise chlorine, sulphur and phosphorous species as the main degradation agents and to identify the corrosion products naturally formed during the long-term interaction with the burial soil constituents. The findings show also that the galvanic coupling between the two dissimilar metals, i.e. Cu and Au, lead to enhancement of corrosion phenomena causing the spalling of the gold thin film and the disfigurement of the object. From a conservation point of view, the results suggest a targeted use of low-toxic inhibitors to hinder the detrimental role of chlorine as possible responsible of future further severe degradation phenomena. In conclusions, the micro and nano-chemical, structural and morphological investigations in a depth range from a few nanometers to micrometers have revealed the complex nature of corroded surface of ancient gold coated artefacts, highlighting some specific aspects related to their peculiar degradation mechanisms thus extending the scientific relevance of the tailored use of complementary and integrated surface and subsurface analytical techniques for the investigation of ancient coated artefacts. (C) 2018 Elsevier B.V. All rights reserved.

High-tin copper-based artefacts, recently discovered during archaeological excavations of the Italic necropolises of ancient Abruzzo (Central Italy), were investigated in order to determine the chemical composition and metallurgical features of the alloys and the micro-chemical and micro-structural nature of the corrosion products grown during the long-term burial. The investigated Cu-based artefacts, dated back to 6th and 5th centuries BC, were defensive weapons, in particular bronze belts and disc armors with embossed decoration and ornamental objects such as rivets, buckles and small rings that were applied to large belts to form complex patterns with the addition of small and large shaped pieces of amber. The analytical characterisation was performed by means of the combined use of scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), optical microscopy (OM) and X-ray diffraction (XRD) analysis. The results put in evidence that the bronze artefacts were manufactured by casting an unusual high-tin bronze alloy in a ceramic bivalve mould thus producing artefacts with a silver-like appearance. In some cases the manufacturing process included also tailored cycles of thermal treatments and hot mechanical working under reducing conditions and well defined thermal parameters in order to shape the high-tin alloys in the form of sheets. The ancient metallurgists have also used low tin bronze alloys coated with a thin layer of tin for producing a highly reflective silver-like appearance. From a corrosion point of view, the main alloying elements have formed degradation products in the form of stratified structures containing tin oxides (romarkite and cassiterite), cuprous oxide, copper carbonates (azurite and malachite) and dangerous chlorine-based compounds (nantokite and atacamite polymorphs). These findings show that there is a strict interaction with the soil components and the pH variation of the different areas of the necropolis, suggesting that post-burial degradation phenomena occur. It can be concluded that SEM-EDS, XRD and OM can be successfully combined for studying the corrosion products of archaeological copper-based artefacts, thus helping to choose the best strategies for the long-lasting conservation of these ancient artworks.

The mineral species forming the patinas naturally grown on copper-based artefacts retrieved from sea-water have been studied by means of the combined use of scanning electron microscopy coupled with energy dispersive spectrometry (SEM+EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and optical microscopy (OM). The selected artefacts include fragments of bronze statues and commonly used objects that were recently found in the Sicilian channel and along the Italian coasts. Our findings show that the composition and structure of the corrosion products is different depending on several parameters and the local environment. Furthermore, the study of the metallurgical features of the artefacts revealed also some interesting manufacturing details. From a conservation point of view, the SEM-EDS, XPS, FTIR, XRD and OM results show, as a whole, that the alloy matrix is often heavily corroded also in the bulk where the ubiquitous and dangerous presence of chlorine was always detected as the main dangerous corroding agent. Chlorine forms nantokite (CuCl) which is the species inducing the cyclic and inexorable copper corrosion commonly called "bronze disease". Other elements from the marine environment that contribute to form the patina are sulphur, phosphorous and seawater cations like Ca and Mg. On the basis of our results, an attempt is made to find a correlation between the nature of the patina, the chemical composition of the objects and the marine retrieving environment where the objects lived for many hundreds, or thousands, years. From a conservation point of view, our findings may be useful to suggest, or select, tailored conservation methods and materials with the purpose to turn the dangerous copper chlorides, or oxy-chlorides (atacamite and its polymorphs), into less reactive and more stable phases. This should hamper the copper cyclic reaction thus ensuring a long-term chemical-physical stability to the bronze artefacts.

The development of active materials for the protection of metallic substrates from corrosion is a task of primary importance for many applications. Several organic compounds were studied to investigate their corrosion inhibition potential in order to replace hazardous compounds [1-2]. The purpose of this research has been the investigation of the efficiency of a new environmental-friendly anticorrosive coating that takes advantage from the synergist effect of a biopolymer matrix combined with amino acids. The inhibition of the corrosion of the copper-based alloys has been studied using Chitosan (CH) as a biopolymer and L-Cysteine (Cy) as amino acid. The latter was selected since, in addition to the amino group, Cy also contains the -SH groups which have a strong affinity with copper. The CH/Cy coatings were optimized paying particular attention to the requirements necessary for their application in the field of cultural heritage. To evaluate the protective efficacy of the coatings, accelerated corrosion tests, purposely tailored, were carried out on bare and coated metal disks. Our tests reveal that the efficiency in the corrosion inhibition increases with a minimum amount of Cy (0.5 mg/ml). The nature of the protective film formed on the copper-based alloy surface was analysed by FTIR spectroscopy 42 whereas the surface modifications due to the corrosion treatments were characterized by Optical Microscopy. The experimental data show that the CH/Cy coatings have a protective action onto the copper-based alloy surface with a consequent inhibition of the corrosion process. [1] G. Giuliani, M. Pascucci, C. Riccucci, E. Messina, M. Salzano de Luna, M. Lavorgna, G.M. Ingo, and G. Di Carlo, Progress in Organic Coatings, 122, 138-146 (2018). [2] M.A. Amin, K.F. Klaled, Q. Mohsen and H.A. Arida, Corrosion Science 52, 1684-1699 (2010).

Nitric oxide (NO), the major component of NOx, is one of the most dangerous air pollutants and many efforts are devoted to find an efficient catalytic way for its abatement. Different reactions are proposed, the most simple one is the direct NO decomposition to give N2 + O2. In the large family of zeolites containing transition metal ions, the Cu-ZSM-5 is attracting much attention because it is unique catalyst able to decompose NO significantly at temperatures between 673 and 773 K. Although it is widely accepted that reduced copper species were responsible for the NO decomposition and that the reaction proceed through a redox cycle, the nature of the active sites is still not completely clear, giving rise to a strong scientific debate on it. We provided some evidences that dimeric Cu(I) species, produced by self-reduction of Cu(II) during the thermal activation of a Cu-ZSM-5 (Si/Al=25) catalyst in He or under vacuum, are the sites where N2 is generated from two adsorbed NO molecules, and from which O2 desorbs from the catalyst at the steady state. Such dimeric Cu(I) species, located on the opposite sides of the ten-membered rings in the straight channels of the Cu-ZSM-5 framework, as suggested by DFT calculations, are able to adsorb irreversibly N2 at low temperature. Interestingly, the amount of irreversible N2 adsorbed at 273 K per total amount of copper as well as the turnover frequency (TOF) of the NO decomposition had both a typical volcano-like shape when they were plotted against the Cu exchange level, i.e. the copper content. Combining these data, a linear relationship was found between the TOF and the amount of irreversible N2 per total copper. The slope of such a linear relationship, i.e. the TOF calculated by taking into account only the copper concentration titrated by the irreversible N2 adsorption, is a constant value regardless the copper loading and the Si/Al ratio of the ZSM-5 framework. By contrast, the Cu-S-1 (MFI framework type without framework Al), Cu-Y and [Al]-MCM41 catalysts are unable to adsorb N2 irreversibly at 273 K and are inactive for the NO decomposition under the same experimental condition as used for Cu-ZSM-5 preparation. These findings, as a whole, strongly suggest that dimeric Cu(I) species are very likely the active sites for NO decomposition on Cu-ZSM-5 catalysts. [1] G. Moretti, G. Ferraris, G. Fierro, M. Lo Jacono, S. Morpurgo and M. Faticanti, J. Catal., 232, 476 (2005)

Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels). Here, we probe the catalytic activity of anatases for the oxidative desulfuration of dibenzothiophenes under atmospheric pressure and mild temperatures. Specifically, for this study, we have taken advantage of the high stability of the (101) anatase surface to obtain a variety of uniform colloidal mesocrystals (approximately 50 nm) with adequate orientational order and good textural properties (pores around 3–4 nm and surface areas around 200 m2/g). Ultimately, this stability has allowed us to compare the catalytic activity of anatases that expose a high number of aligned single crystal-like surfaces while differing in controllable surface characteristics. Thus, we have established that the type of tetrahedral coordination observed in these anatase mesocrystals is not essential for oxidative desulfuration and that both elimination of sulfates and good textural properties significantly improve the catalytic activity. Furthermore, the most active mesocrystals have been used to model the catalytic reaction in three-(oil–solvent–catalyst) and two-phase (solvent–catalyst) systems. Thus, we have been able to observe that the transfer of DBT from the oil to the solvent phase partially limits the oxidative process and to estimate an apparent activation energy for the oxidative desulfuration reaction of approximately 40 kJ/mol in the two-phase system to avoid mass transfer limitations. Our results clearly establish that (101) anatase mesocrystals with excellent textural properties show adequate stability to withstand several post-treatments without losing their initial mesocrystalline character and therefore could serve as models for catalytic processes different from the one studied here.

Gold coated commonly used copper-based objects such as studs, brooches, clasps and a small pendants, dating back to 16th-17th centuries CE, were studied by means of the combined use of FE-SEM/EDS, TOF-SIMS, ?- FTIR, XRD and optical microscopy (OM). In particular, the surface and subsurface chemical features of the gilded objects were investigated, revealing some aspects of the manufacturing methods as well as disclosing the mechanism of degradation occurring during the long-term burial in the soil and the agents involved in this process. Our investigation has made possible to identify the chemistry of the decorative Au layer deposited by using an amalgam, i.e. the fire-gilding, its structure and the corrosion products naturally formed from the interaction with the surrounding environment. The main degradation agents are chlorine, sulphur and phosphorous species that gave rise to the formation of different corrosion products. Indeed the corrosion phenomena are boosted by the metal galvanic coupling which makes gilded-metal art works unstable from a chemical-physical point of view. In perspective of preservation, our results suggest that it is important to prevent the interaction between moisture and nantokite (CuCl), located at the interface between the gilding layer and the substrate, in order to avoid further severe degradation phenomena such as "bronze disease" which transforms the copper substrate into a greenish powder.

By means of the combined use of X-ray photoelectron spectroscopy (XPS), optical microscopy (OM) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) the surface and subsurface chemical and metallurgical features of silver counterfeited Roman Republican coins are investigated to decipher some aspects of the manufacturing methods and to evaluate the technological ability of the Roman metallurgists to produce thin silver coatings. The results demonstrate that over 2000 ago important advances in the technology of thin layer deposition on metal substrates were attained by Romans. The ancient metallurgists produced counterfeited coins by combining sophisticated micro-plating methods and tailored surface chemical modification based on the mercury-silvering process. The results reveal that Romans were able systematically to chemically and metallurgically manipulate alloys at a micro scale to produce adherent precious metal layers with a uniform thickness up to few micrometers. The results converge to reveal that the production of forgeries was aimed firstly to save expensive metals as much as possible allowing profitable large-scale production at a lower cost. The driving forces could have been a lack of precious metals, an unexpected need to circulate coins for trade and/or a combinations of social, political and economic factors that requested a change in money supply. Finally, some information on corrosion products have been achieved useful to select materials and methods for the conservation of these important witnesses of technology and economy.

By means of scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), counterfeited Roman Republican coins are investigated to decipher some aspects of the manufacturing methods and to evaluate the technological ability of the Roman metallurgists to produce thin silver films. The results demonstrate that over 2000 ago important advances in the technology of thin film deposition on metal substrates were attained by Romans that produced counterfeited coins by combining sophisticated micro- and nano-plating methods and tailored surface chemical modification based on the mercury-silvering process. The ancient metallurgists were able systematically to manipulate metals at a micro and nano scale to produce adherent precious metal layers with a uniform thickness ranging from one to a few micrometers. Romans were able to create the appearance of solid silver coins without knowledge about the chemical-physical processes but using only their experienced skill [1]. Furthermore, the results suggest that, contrary to the more recent times, counterfeited coins were likely produced by the issuing official authorities too. The production was aimed firstly to save expensive metals as much as possible allowing profitable large-scale production at a lower cost. The driving forces could have been a lack of precious metals, an unexpected need to circulate coins for trade and/or a combinations of social, political and economic factors that requested a change in money supply. Finally, useful information on degradation agents have been achieved to tailor the selection of conservation methods able to save these important witnesses of art, technology and economy. [1] G.M. Ingo, G. Guida, E. Angelini, G. Di Carlo, A. Mezzi, G. Padeletti, Acc. Chem. Res. 46, 2365 (2013).

Copper-based alloys are affect by degradation processes leading to the formation of surface patinas, whose composition depends on several parameters such as the alloy composition, metallurgical features and environmental conditions. Naturally grown patinas are typically detected onto the surface of modern bronze works of art [1] and strictly affect the surface reactivity. The production of representative patinas onto bronze substrates is a key issues in order to obtain model systems which can be used for the development and validation of appropriate conservation strategies. In this study, we have prepared different artificial representative patinas by using a quaternary copper-based alloy (Cu-Sn-Zn-Pb) with chemical composition and metallurgical features similar to those of valuable modern works of art [1]. In order to produce degradation products commonly observed onto their surface, chloride and sulphate species were used to induce corrosion processes. Different patinas were produced by changing some experimental parameters, as concentration of corrosive species, temperature and ageing time. The composition and structural properties of the patinas were investigated by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy. The results allow to identify degradation products and to distinguish polymorph species. In the case of chloride induced patina formation, red Cu2O (cuprite) and green Cu2(OH)3Cl polymorphs were mainly detected. When the patina formation is induced by sulphate species, it mainly consists of blue Cu4SO4(OH)6 polymorphs. [1] D.E. Couture-Rigert, P.J. Sirois, E.A. Moffatt, Studies in Conservation, 57, 142 (2012).

Objective: Desquamative gingivitis (DG) represents the gingival manifestation associated with several mucocutaneous disorders and systemic conditions. Little is known of whether or not DG could influence the onset or progression of plaque-related periodontitis. In this study, the potential impact of DG on plaque-related attachment loss and pocket formation has been evaluated. Methods: A cross-sectional evaluation of 12 patients with DG [eight oral lichen planus (OLP), four mucous membrane pemphigoid (MMP)], never treated for DG lesions or plaque-related periodontitis, was carried out. Probing depth (PD), clinical attachment loss (CAL), full-mouth plaque (FMPS), and bleeding (FMBS) scores were evaluated at six sites per tooth. Clinical parameters of sites with DG lesions were compared with that of DG unaffected sites. Results: Median PD and CAL, as well as FMPS and FMBS, were not significantly different (P > 0.05 Mann–Whitney test) for both OLP and MMP patients. However, a negative association between DG lesions and PD 6 mm (only for OLP: OR = 3.83) were found to be significant. Conclusions: The potential interference between DG lesions and periodontitis needs further prospective investigation; nonetheless, a higher level of attention might be prudent.