•FT-IR and NMR spectroscopies were used for the discrimination of samples with different geographical provenance.•T1ρ(H) values, obtained from variable contact time NMR experiments highlighted the ...differences between wood groups.•Principal component analysis of NMR and IR data allowed the most effective discrimination of wood due to provenance.
13C nuclear magnetic resonance and mid-infrared spectroscopies were used for characterizing changes in the chemical structure of wood polymers (cellulose, hemicellulose and lignin) in relation to the tree growth location. Samples of three provenances in Europe (Finland, Poland and Italy) were selected for studies. The requirement was to use untreated solid wood samples to minimize any manipulation to the nanostructure of native wood.
The results confirm that the chemical and physical properties of samples belonging to the same wood species (Picea abies Karst.) differ due to the origin. Both FT-IR and dynamic NMR spectroscopies were able to correctly discriminate samples originating from three different provenances in Europe. Such methods might be very useful for both, research and understanding of wood microstructure and its variability due to the growth conditions.
► The protein of maize, the pea protein, and two soy proteins were evaluated. ► Dissolution tests at different pH, FT-IR analysis, and shear tests were carried out. ► Proteins became more unfolded ...and solvated after pH increase. ► Variations in the acidity level did not change the conformation of all proteins. ► Pea protein is a valid alternative to soy, zein is not suitable as a wood adhesive.
Adhesives industry is increasingly interested in products coming from natural and renewable resources, because of the limited reserve of oil, its prices variability and its negative impact on both environment and human health. However, soy crops are mainly concentrated in the Americas, and are not so widespread in Europe. Thus, it is interesting to evaluate if other vegetable proteins more common in Europe are compatible for their use as wood adhesives. In this study, zein, a protein component of maize (Zea mays L.), the pea (Pisum sativum L.) protein, and two products based on soy (Glycine max L.) proteins, one treated with alkali and the other not, were compared in order to verify their utilisation as wood adhesives for indoor applications.
Dissolution tests in both water and ethanol/water mixture at different pH values, and FT-IR analysis in the same conditions were carried out. Also the effect of the addition of denaturing agents such us urea and guanidine hydrochloride was evaluated. Solubility results showed that, as expected, water soluble fraction of these proteins increased significantly by increasing pH: both the 2 soy proteins and the pea protein evidenced soluble fraction higher than 80% at pH 10, while for zein, this parameter was always lower than 30%.
Moreover, water seemed to be a better solvent than the ethanol/water mixture. In fact, in one case a solubility decrease was observed when ethanol was added to water.
Standard bonding tests on wood-to-wood joints were carried out according to EN 205, both in dry and in wet conditions, this latter after 4 days of immersion in water. Shear strength values were above the minimum threshold limit of 10MPa required by the standard for both the 2 soy and the pea proteins. In contrast, all proteins were not suitable for wet conditions.
Pea protein seemed to be a valid alternative to soy proteins, which is realistic considering that the amino acid profiles of pea and soy proteins are similar. However, like for the soy protein, it is essential to improve the water resistance with an additive. In contrast, zein did not seem suitable as wood adhesive, because of its low solubility in all the considered conditions.
The adhesives industry is increasingly interested in products coming from natural and renewable resources. The aim of the present work was to improve the water resistance of soy-based proteins by ...using synthetic and formaldehyde-free additives. These include polyamide-amine epichlorohydrin (PAE), different types of isocyanates, and combinations of these cross-linkers between them and with other agents, including metal ions. In addition, the effect of both curing temperature and maturation time was assessed. Performances were evaluated by means of shear strength tests, solubility tests, and spectroscopic analysis. The obtained results showed that while isocyanates reacted completely but with water instead of proteins, tests with PAE were generally successful. In fact, the insoluble residue as well as the shear strength in wet conditions dramatically increased after PAE addition. Moreover, the wet performances of protein/PAE formulations appreciably increased gluing at 60 °C instead of room temperature. Furthermore, the maturation time had a positive effect on the formulations where metal ions were added, both for solubility and wet shear strength. Actually, for the very long conditioning time of 3 months, a significant and substantial increase of wet shear strength was observed for the series protein/PAE/aluminum.
Wettability of 6 different wood species commonly used in the woodworking industry in the Mediterranean region was evaluated in this study. The species were Norway spruce (
Picea abies Karst.), ...umbrella pine (
Pinus pinea L.), oak (
Quercus sp.p.), chestnut (
Castanea sativa Mill.) beech (
Fagus sylvatica L.) and poplar (
Populus sp.p.), and their surfaces were machined according to 3 different processes: planing, sanding and disc-sawing. Measurement of dynamic contact angle and extractives (evaluated by means of GC–MS analysis) were carried out on freshly cut and 24
h air exposed surfaces, in order to also evaluate the effect of ageing on wettability. The parameterisation of the contact angle vs. time curves allowed for the systematic statistical elaboration of data, in order to find the relationships existing between the four parameters characterising the dynamic curves and the considered factors (species, machining, ageing). The evaluations evidenced a different influence of these factors on the chosen parameters and hence some of them could be used to reliably assess both wood wettability and the effects of the factors here considered. In general softwoods showed higher contact angles than hardwoods due to the different anatomy and to the presence of resins and terpenes in addition to fatty acids and phenolic compounds, also present in hardwoods. After 24
h air exposure a shifting upwards of dynamic contact angle curves was observed but, despite the variation in surface composition, this shifting was imputable to other inactivation factors. Also machining appreciably influenced wettability, and the sanded surfaces were the most wettable as compared to both the planed and the disc-sawn ones. On the other hand, these observed differences diminished after ageing due to the levelling effect of inactivation that overcame surface inhomogeneities.
The bondline chromatic alteration of poly(vinyl acetate) (PVAc) in wood assemblies has an appreciable impact on the aesthetic characteristic of these products (mostly important for panels used in ...furniture). While the origin of this phenomenon has been explained for the cases of pure polymers and wood substrates alone, present work investigates about the origin of discoloration for the case of bondlines prepared with selected wood species (cherry and maple) and two commercial PVAc dispersions, one containing and one not containing aluminum ions. Assemblies were exposed to temperature and UV light. The comparison (carried out through GC-MS analysis) among the compounds extracted by these species before and after exposure allowed identifying specific flavonoids that were used as model-compounds to replicate the discoloration process in laboratory. Thus, using spectrophotometric measurements and TLC analysis it is shown that discoloration is related to the presence of aluminum in the dispersion, whose interaction with flavonoids in wood generates different forms of complexes that can be modified upon irradiation and emitting in the visible range. Although the specific involved compounds are species-related, it can be suggested that the identified mechanism at the basis of discoloration in PVAc-wood bondlines has general validity.
•The bondline chromatic alteration of poly (vinyl acetate) in wood assemblies has been investigated.•The mechanism of discoloration was reproduced in laboratory using model flavonoids and aluminum.•Various analyses (GC-MS, spectrophotometry, TLC, EDX) were used to study the produced complex.•The cause of discoloration was found and demonstrated on PVAc latexes.•Metal-flavonoid complexes are formed in the bondline. They can modify upon light exposure and emit in the visible spectrum.
The superior properties and the natural beauty of wood make it a desired material for various applications including construction, interior/exterior design or other uses. Unfortunately, wood as any ...other material is a subject of deterioration due to several factors, including among others; weathering, oxidation, biodegradation, wear or decay. It is important therefore to assure the performance of wood products during their functional service life. On the other hand, not just the functional performance is an issue, but it is extremely important to consider also aesthetical service life. The goal of this work was to study how the progress of surface changes affects customer perception of the wood. The effect of gender, age, education and nationality has been included in the research. A dedicated software tool has been developed within the frame of SWORFISH project and in collaboration with COST Action FP1006 "Bringing new functions to wood through surface modification". The set of 256 respondents representing different social groups has been requested to choose between images of wooden surfaces exposed to natural weathering and displayed on the computer desktop. The choice was related to the personal "end of aesthetical service life" and based only on aesthetical impression of the respondent. The same test has been repeated providing additional information defining the time of samples exposition to weathering. It was possible, after analysis of responses, to define the time when the wood surface is not anymore acceptable and requires maintenance. The statistical evaluation high-lighted difference between respondent groups but also change of tolerance for surface imperfection after realizing the efforts related to frequent repairs.
Some fossil wooden samples of the Tertiary period, extracted from the crater of the kimberlite BHP-Panda pipe from the Lac de Gras region (in the Canadian sub-Arctic area), and previously identified ...as Sequioxylon canadense Blokhina, were chemically examined to both assess their state of preservation and discuss about the possible causes of their decay. The chemical composition of fossils (in terms of holocellulose, lignin and ash amounts) was evaluated by means of wet analyses, together with the chromatographic analysis of dichloromethane extracts, and additionally measurements of the cation exchange capacity (CEC) of fossils were also carried out. The analyses revealed the complete loss of holocellulose (except for 2 out of 9 samples), whereas lignin became the predominant component, together with ash (whose amount in one case was as high as 47.5%). Moreover, CEC data showed that all acid carboxyls were transformed into carboxylates. They represented the most important form of residual carboxyl groups in the fossils, and were even more abundant than in the reference (fresh) wood. All these occurrences evidenced a generally high level of decay for the fossils, as a consequence of water leaching during burial, which determined both the hydrolysis of esters groups and the partial depolymerisation of lignin.
L’état de conservation de certains échantillons de bois fossile de l’Ère Tertiaire, provenant de carottages de kimberlite dans la zone du Lac de Gras (région subarctique canadienne) et autrefois identifiés comme Sequioxylon canadense Blokhina, a été évalué chimiquement. Les causes possibles de leur dégradation ont aussi été discutées. La composition chimique des fossiles (mesurée avec les teneurs en holocellulose, en lignine et en minéraux) a été évaluée avec des méthodologies d’analyse gravimétrique et avec des analyses chromatographiques sur l’extrait au dichlorométhane. Des mesures de capacité d’échange cationique (CEC) ont été en outre conduites sur des fossiles. Les analyses ont montré la complète disparition de la teneur en holocellulose (sauf pour 2 échantillons sur 9), tandis que la lignine est devenue le composé le plus abondant, ainsi que la cendre (dont le montant atteint 47,5 % dans un cas). Les données de la CEC ont aussi mis en évidence que le carboxyles acides ont été transformés en carboxyles salifiés, qui représentent la forme restante de carboxyles la plus importante dans les fossiles (encore plus abondants que dans le bois de référence). Toutes ces circonstances indiquent que les fossiles sont très dégradés. Cette dégradation est une conséquence de l’écoulement pendant l’enfouissement, qui a causé l’hydrolyse des groupes estérifiés et la dépolymérisation de la lignine.
SAMHD1 is a host restriction factor that functions to restrict both retroviruses and DNA viruses, based on its nuclear deoxynucleotide triphosphate (dNTP) hydrolase activity that limits availability ...of intracellular dNTP pools. In the present study, we demonstrate that SAMHD1 expression was increased following human cytomegalovirus (HCMV) infection, with only a modest effect on infectious virus production. SAMHD1 was rapidly phosphorylated at residue T592 after infection by cellular cyclin-dependent kinases, especially Cdk2, and by the viral kinase pUL97, resulting in a significant fraction of phosho-SAMHD1 being relocalized to the cytoplasm of infected fibroblasts, in association with viral particles and dense bodies. Thus, our findings indicate that HCMV-dependent SAMHD1 cytoplasmic delocalization and inactivation may represent a potential novel mechanism of HCMV evasion from host antiviral restriction activities.
Urothelial carcinoma of the bladder is one of the most prevalent cancers worldwide, diagnosed as muscle invasive in 25% of cases. Although several studies have demonstrated an overall 5% absolute ...survival benefit at 5 years with cisplatin-based combination neoadjuvant treatment, administration of chemotherapy prior to radical cystectomy (RC) in muscle-invasive bladder cancer (MIBC) patients is still a matter of debate. This may be due to the perceived modest survival benefit, cisplatin-based chemotherapy ineligibility, or fear of delaying potentially curative surgery in non-responders. However, immunotherapy and novel targeted therapies have shown to prolong survival in advanced disease and are under investigation in the neoadjuvant and adjuvant settings to reduce systemic relapse and improve cure rates. Genomic characterization of MIBC could help select the most effective chemotherapeutic regimen for the individual patient. Large cohort studies on neoadjuvant treatments with immune checkpoint inhibitors (ICIs) and molecular therapies, alone or combined with chemotherapy, are ongoing. In this review, we trace the development of neoadjuvant therapy in MIBC and explore recent advances that may soon change clinical practice.
Natural Killer (NK) cells are key innate effectors of antiviral immune response, and their activity changes in ageing and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, ...we investigated the age-related changes of NK cell phenotype and function during SARS-CoV-2 infection, by comparing adult and elderly patients both requiring mechanical ventilation. Adult patients had a reduced number of total NK cells, while elderly showed a peculiar skewing of NK cell subsets towards the CD56
low
CD16
high
and CD56
neg
phenotypes, expressing activation markers and check-point inhibitory receptors. Although NK cell degranulation ability is significantly compromised in both cohorts, IFN-γ production is impaired only in adult patients in a TGF-β−dependent manner. This inhibitory effect was associated with a shorter hospitalization time of adult patients suggesting a role for TGF-β in preventing an excessive NK cell activation and systemic inflammation. Our data highlight an age-dependent role of NK cells in shaping SARS-CoV-2 infection toward a pathophysiological evolution.
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