Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Int J Biol Macromol ; 266(Pt 2): 130920, 2024 May.
Article in English | MEDLINE | ID: mdl-38513902

ABSTRACT

Veneers obtained via hydrothermal treatment serve to enhance the aesthetic appeal of furniture and other wooden surfaces. However, the impact of this treatment on the chemical composition of holocellulose and lignin, coupled with their resistance to ultraviolet (UV) irradiation, remains a relatively unexplored area requiring further investigation. In the experiment, wood samples of three distinct species underwent hydrothermal treatment followed by exposure to UV aging. Parameters including colour, contact angle, and acid-base properties were examined alongside their chemical alterations during these processes. These observed properties were then correlated with changes identified through FT-IR and Py-GC/MS analyses to uncover their molecular origins. Through these methods, the study offered insights into the chemical transformations driving the observed alterations. Findings revealed the considerable impact of hydrothermal treatment on these properties and their propensity for modification under UV radiation. In most test variations, hydrothermal treatment amplified tendencies toward colour changes, increased hydrophobicity, and basicity. Analysis of chemical changes suggested the degradation of polysaccharides due to hydrothermal treatment and lignin breakdown under UV irradiation. Understanding these molecular changes provides a foundation for mitigating the adverse effects of hydrothermal wood treatment.


Subject(s)
Cellulose , Lignin , Wood , Lignin/chemistry , Wood/chemistry , Cellulose/chemistry , Ultraviolet Rays , Spectroscopy, Fourier Transform Infrared , Gas Chromatography-Mass Spectrometry , Hydrophobic and Hydrophilic Interactions
2.
Molecules ; 27(16)2022 Aug 16.
Article in English | MEDLINE | ID: mdl-36014467

ABSTRACT

Environmental conditions present in mines generally are very favourable to decay; high temperature, high humidity, variable oxygen content, numerous metal-wood connections and the presence of a high content of inorganic compounds typical of mines have a significant impact on the biotic and abiotic degradation factors. The state of conservation of wooden artefacts from the Zloty Stok (Poland) gold mine was investigated using a multi-analytical approach. The aim was to select the conservation treatments that would stop decay and improve the conditions and dimensional stability of the wood. FT-IR and Py-GC/MS were used to assess the state of preservation of lignocellulosic material. ED-XRF and SEM-EDS were used to determine-and XRD to identify crystalline phases-salts and minerals in the wood structure or efflorescence on the surface. Highly degraded lignocellulosic material that had undergone depolymerisation and oxidation was found to be severely contaminated by iron-based mineral substances, mainly pyrite, and in some cases greigite and magnetite. The presence of inorganic salts made it difficult to choose the best consolidating material to reduce the level of decay and improve the dimensional stability of the wood.


Subject(s)
Gold , Salts , Gold/analysis , Minerals/chemistry , Mining , Spectroscopy, Fourier Transform Infrared , Wood/chemistry
3.
Materials (Basel) ; 15(11)2022 Jun 06.
Article in English | MEDLINE | ID: mdl-35683335

ABSTRACT

Tilia cordata Mill. is a favourite tree used in urban spaces. For this reason, it is important to know its sensitivity to environmental stress, which is particularly burdensome for vegetation in urban spaces. The aim of the study was to investigate the properties necessary to control the growth of these trees and their subsequent use, i.e., chemical properties (percentage contents of cellulose, holocellulose, lignin, pentosans and substances soluble in NaOH and EtOH) as well as the chemical elements (K, Na, Mg, Ca and Fe, Zn, Cu, Pb, Cd, B, Ni, Cr, Al, As and Hg) and selected hygroscopic properties (hysteresis and sorption isotherms). Trees of Tilia cordata Mill. growing in environments exposed to environmental stress of varying severity were examined. Regardless of the growth conditions, in terms of its chemical composition, bark differs significantly from wood, showing twice the contents of soluble substances in NaOH and lignin and half the content of polysaccharides. Growth conditions clearly affect the range of selected chemical components in bark, e.g., substances soluble in ethanol, cellulose, or lignin. The main inorganic elements in bark and wood are Na, K, Ca, Mg and Zn. In bark, a relationship was found between the content of most chemical elements and differing environmental growth conditions. It was shown that environmental stress influenced the hygroscopic properties of wood and bark, which are a consequence of the percentage of chemical components.

4.
Materials (Basel) ; 12(12)2019 Jun 23.
Article in English | MEDLINE | ID: mdl-31234564

ABSTRACT

It can be found that reaction mechanisms and interactions between wood and organosilicone compounds have not been sufficiently explored. The aim of the study was to determine bonds formed between either cellulose or lignin and methyltrimethoxysilane (MTMOS) during a catalytic silanization reaction. Silanization was performed in the presence of two catalysts of a diverse mechanism of functionalization: aluminum acetylacetonate (Al(acac)3) and acetic acid (AcOH). For this purpose, FT-IR, 13C and 29Si NMR techniques were used. Cellulose silanization efficiency without a catalyst was unlikely. Lignin undergoes a silanization reaction with alkoxysilanes much easier than cellulose. The results showed new bonds between biopolymers and the silanising agent. The new bonds were confirmed by signals at the FT-IR spectra, e.g., 770 cm-1 and 1270 cm-1 (Si-CH3), and at the NMR signal coming from the T1, T2 and T3 structures. Efficiency of reaction was confirmed by atomic absorption spectroscopy (AAS) analysis.

5.
Polymers (Basel) ; 11(5)2019 May 08.
Article in English | MEDLINE | ID: mdl-31071988

ABSTRACT

The aim of the research is to identify the changes which occur in lignin from miscanthus and sorghum, one of the main biomass components, as a result of an anaerobic digestion (AD) process. The percentage content and structure of lignin before and after the fermentation process were analysed using biomass harvested in two growing periods-before and after vegetation. It was shown that plants at different developmental stages differ in lignin content. During plant growth, the lignin structure also changes-the syringyl-to-guaiacyl ratio (S/G) increases, whereas the aliphatic and aromatic structure ratio (Al/Ar) decreases. The AD process leads to an increase in percentage lignin content in cell walls, and the increase is higher for plants harvested during vegetation. It has been shown in studies that the methane fermentation of miscanthus and sorghum produces waste containing a large amount of lignin, the structure of which is altered relative to native lignin. The quantity and the new, simplified structure of lignin create new possibilities for using this aromatic polymer.

6.
Chemosphere ; 212: 67-78, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30142567

ABSTRACT

The aim of the study was to compare specimens of Salix viminalis L. able to grow in polluted mining sludge (A1) with specimens of the same willow clone growing in two unpolluted areas (A2 and A3). Plants from the polluted area were characterized by the highest accumulation of the majority of elements in their organs with a clear limitation of their uptake to roots and effective translocation to aboveground organs. Willows from the unpolluted areas were characterized by significantly higher biomass than the treated plants, as shown in the content of cellulose/holocellulose. The different chemical characteristics of the substrates influenced tree physiology, including the organic acids and phenolic compounds profile and/or content. The total content of organic acids in lateral roots was higher for S. viminalis L. grown in unpolluted areas, while for leaves the opposite situation was observed. However, their creation was significantly correlated with the content of the majority of elements in the organs of S. viminalis L. Enhanced synthesis of phenolic compounds in roots (besides quercetin) and in leaves (besides myricetin and quercetin) was confirmed in the polluted area, and correlated with metal content in plant organs. Resilient plants characterized not only by their survivability but also by their effective phytoextraction of toxic metals, have great potential for widespread practical application on highly polluted mining sludge and for reducing the associated threat to human health. The obtained results suggest that further investigation of these plants is necessary to determine the mechanism(s) responsible for their high survivability.


Subject(s)
Biodegradation, Environmental , Metals/isolation & purification , Plant Leaves/metabolism , Plant Roots/metabolism , Salix/metabolism , Soil Pollutants/metabolism , Biomass , Metals/metabolism , Salix/growth & development
7.
J Clin Immunol ; 38(4): 538, 2018 May.
Article in English | MEDLINE | ID: mdl-29728794

ABSTRACT

The original version of the article, "Circulating T Cells of Patients with Nijmegen Breakage Syndrome Show Signs of Senescence" incorrectly listed the affiliation of the fourth author, Iwona Solarska. The correct affiliation is "Molecular Biology Laboratory, Institute of Hematology and Transfusion Medicine.

8.
Article in English | MEDLINE | ID: mdl-29775396

ABSTRACT

Trees of Scots pine (Pinus sylvestris L.) are known for their effective phytoextraction capabilities. The results obtained in this study point to the significant role of substrate composition and chemical characteristics in the phytoextraction potential of this species. A multi-elemental (53 elements) analysis of pines from unpolluted (soil) and polluted (post-flotation tailings) sites was performed using inductively coupled plasma optical emission spectrometry. The analyzed flotation tailings were characterized by alkaline pH (7.19 ± 0.06) and significantly higher conductivity (277.7 ± 2.9 µS cm-1) than the soil (pH = 5.11 ± 0.09; 81.3 ± 4.9 µS cm-1). The two substrates also differed with respect to the contribution of the clay fraction (0% in the unpolluted and 8% in the polluted substrate). The specimens of P. sylvestris growing on flotation tailings had significantly smaller height (381 ± 58 cm) and total aboveground biomass (4.78 ± 0.66 kg) than the trees growing in soil (699 ± 80 cm and 10.24 ± 2.10 kg). The biomass of the trunk, twigs and branches, and needles of the trees from polluted sites was between 40.0% and 48.7% of the biomass of the same organs of the control trees. Generally, the organs (trunk, twigs and branches, needles) of the P. sylvestris specimens from polluted sites had significantly higher concentrations of Au, Al, Ba, Cd, Co, La, Lu, Ni, Pd, Sc, Zn, and lower concentrations of B, Bi, Ca, Ce, Er, In, K, Mg, Na, Nd, P, Pr, Re, Se, Sr, Te than in the control plants, these metals being accumulated effectively in the whole of the aboveground biomass (BCF>1). Although the concentration of the majority of elements was significantly higher in the flotation tailings, significantly higher concentrations of these elements were observed in the tree organs from unpolluted sites, which points to the important role of substrate characteristics in the phytoextraction efficiency of P. sylvestris.


Subject(s)
Biomass , Pinus sylvestris/chemistry , Pinus sylvestris/metabolism , Soil Pollutants/chemistry , Soil Pollutants/isolation & purification , Soil Pollutants/pharmacokinetics , Adsorption , Biodegradation, Environmental , Environmental Pollution/analysis , Flocculation , Metals/analysis , Metals/isolation & purification , Metals/pharmacokinetics , Refuse Disposal/methods , Refuse Disposal/standards , Soil/chemistry , Soil Pollutants/analysis , Trace Elements/chemistry , Trace Elements/isolation & purification , Trace Elements/pharmacokinetics , Trees/chemistry
9.
Microsc Microanal ; 24(2): 163-182, 2018 04.
Article in English | MEDLINE | ID: mdl-29607797

ABSTRACT

A scanning electron microscopy (SEM) investigation of pine (Pinus sylvestris) and oak (Quercus sp.) wood samples exposed to various types of natural degradation is presented with the aim of discussing the correct identification of multiple degradation signs in waterlogged wood. This is part of an experiment performed at the archeological site of Biskupin (Poland) to evaluate the dynamics of short-term wood degradation during reburial and the suitability of excavated wood as substrate for the fungal attack. The final aim is to support and inform the in situ conservation strategy currently applied to archeological woods. To replicate the burial conditions, wood samples were put into lake water and peat. The samples were removed from the burial environments after 4, 6, 8, and 10 years, and then exposed to laboratory-controlled attack by a brown rot fungus Coniophora puteana and a white rot fungus Coriolus versicolor. SEM images were acquired for all samples before and after the fungal attack. The results showed a slight degradation occurred in the burial environments (soft rot and bacteria). In addition, both typical and previously neglected features of fungal attack were observed, highlighting that the extent of the fungal decay varies according to the previous degree of wood degradation. Some comparisons are provided with archeological wood samples from the Biskupin site.


Subject(s)
Basidiomycota/metabolism , Pinus sylvestris/metabolism , Quercus/metabolism , Wood/metabolism , Biodegradation, Environmental , Microscopy, Electron, Scanning , Models, Theoretical , Poland
10.
J Clin Immunol ; 37(2): 133-142, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28000062

ABSTRACT

PURPOSE: The Nijmegen breakage syndrome (NBS) is an inherited genetic disorder characterized by a typical facial appearance, microcephaly, growth retardation, immunodeficiency, and a strong predisposition to malignancies, especially of lymphoid origin. NBS patients have a mutation in the NBN gene which involves the repair of DNA double-strand breaks (DSBs). Here we studied the peripheral T cell compartment of NBS patients with a focus on immunological senescence. METHODS: The absolute numbers and frequencies of the different T cell subsets were determined in NBS patients from young age till adulthood and compared to age-matched healthy individuals (HI). In addition, we determined the expression of senescent T cell markers and the signal joint T cell receptor excision circles (sjTRECs) content. RESULTS: Our results demonstrate that NBS patients have reduced T cell numbers. NBS patients showed lower numbers of αß+ T cells, but normal γδ+ T cell numbers compared to HI. Concerning the αß+ T cells, both CD4+ as well as CD8+ T cells were excessively reduced in numbers compared to aged-matched HI. In addition, NBS patients showed higher frequencies of the more differentiated T cells expressing the senescent cell marker CD57 and did not express co-stimulatory molecule CD28. These effects were already present in the youngest age group. Furthermore, NBS patients showed lower sjTREC content in their T cells possibly indicative of a lower thymic output. CONCLUSIONS: We conclude that circulating T cells from NBS patients show signs of a senescent phenotype which is already present from young age on and which might explain their T cell immune deficiency.


Subject(s)
Cellular Senescence/genetics , Lymphocyte Count , Nijmegen Breakage Syndrome/blood , Nijmegen Breakage Syndrome/etiology , Phenotype , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Adolescent , Adult , B-Lymphocyte Subsets/immunology , B-Lymphocyte Subsets/metabolism , Biomarkers , Cellular Senescence/immunology , Child , Child, Preschool , Female , Humans , Immunophenotyping , Infant , Male , Mutation , Nijmegen Breakage Syndrome/diagnosis , Nijmegen Breakage Syndrome/metabolism , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell, alpha-beta/genetics , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Receptors, Antigen, T-Cell, gamma-delta/genetics , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Recombination, Genetic , Young Adult
11.
Anal Chim Acta ; 745: 70-7, 2012 Oct 01.
Article in English | MEDLINE | ID: mdl-22938608

ABSTRACT

The macromolecular complexity of wood limits the possibility of obtaining complete chemical information on its alteration in archaeological objects. This paper compares the results obtained in the characterisation of the components of archaeological wood by a classical wet chemical method and by an instrumental method based on pyrolysis in presence of hexamethyldisilazane coupled with gas chromatography/mass spectrometry, Py(HMDS)-GC/MS. We compare the results obtained with the two methods quantitatively. This enables us to evaluate the efficiency of Py(HMDS)-GC/MS in assessing the chemical composition and the state of conservation of degraded wood. The material analysed consisted of reference sound wood and waterlogged wood from the Zólte historical site, located on a small island on Lake Zaranskie in Poland. The samples are from the remains of settlements dating to a period between the 9th and the 12th centuries AD. The results obtained by Py(HMDS)-GC/MS analysis are consistent in the determination of the level of degradation of archaeological wood with the results obtained using traditional techniques. The pyrolysis method is faster, reproducible, and reveals not only the amount but also the quality of the wood constituents, needing a much smaller sample.

12.
Clin Immunol ; 135(3): 440-7, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20167538

ABSTRACT

Selected viruses and immune parameters were monitored in 57 patients with Nijmegen breakage syndrome as a proposed tool for early detection of changes preceding development of malignancy. The following parameters were analysed: (1) viral infections; (2) monoclonal proteins; and (3) B-cell and T-cell receptor gene rearrangements in peripheral blood lymphocytes. Viral infections were detected in 68.4% of patients with a predominance of EBV (63.2%), followed by HBV (19.2%) and HCV (8.8%). Monoclonal gammopathy detected in 38.6% of cases correlated with the presence of EBV DNA (p=0.002) and HCV RNA (p=0.04). Clonal Ig and/or TCR gene rearrangements occurred in 73.9% of patients. The presence of at least one of the studied parameters preceded the development of malignancy in 22 patients. Systematic PCR analysis for viral infections and Ig/TCR gene rearrangements, supplemented by detection of monoclonal proteins, is advantageous in monitoring NBS patients before severe complications of the disease, including cancer, appear.


Subject(s)
Biomarkers, Tumor/analysis , Hematologic Neoplasms/etiology , Nijmegen Breakage Syndrome/immunology , Nijmegen Breakage Syndrome/virology , Virus Diseases/epidemiology , Adolescent , Child , Child, Preschool , Female , Gene Rearrangement, B-Lymphocyte , Gene Rearrangement, T-Lymphocyte , Hematologic Neoplasms/epidemiology , Humans , Infant , Male , Nijmegen Breakage Syndrome/blood , Paraproteinemias , Receptors, Antigen, B-Cell/genetics , Receptors, Antigen, T-Cell/genetics , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocyte Subsets/immunology , Virus Diseases/complications , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...