Optimization of SPME–GC–MS and characterization of floral scents from Aquilegia japonica and A. amurensis flowers

Background The floral scents of plants play a key role in plant reproduction through the communication between plants and pollinators. Aquilegia as a model species for studying evolution, however, there have been few studies on the floral scents and relationships between floral scents and pollination for Aquilegia taxa. Methods In this study, three types of solid-phase micro-extraction (SPME) fiber coatings (DVB/PDMS, CAR/PDMS, DVB/CAR/PDMS) were evaluated for their performance in extracting volatile organic compounds (VOCs) from flowers of Aquilegia amurensis, which can contribute to the future studies of elucidating the role of floral scents in the pollination process. Results In total, 55 VOCs were identified, and among them, 50, 47 and 45 VOCs were extracted by the DVB/CAR/PDMS fiber, CAR/PDMS fiber and DVB/PDMS fibers, respectively. Only 30 VOCs were detected in A. japonica taxa. Furthermore, the relative contents of 8 VOCs were significant different (VIP > 1 and p < 0.05) between the A. amurensis and A. japonica. Conclusions The results can be applied in new studies of the relationships between the chemical composition of floral scents and the processes of attraction of pollinator. It may provide new ideas for rapid evolution and frequent interspecific hybridization of Aquilegia.

Graphene/chitosan/Ag+- doped hydroxyapatite triple composite fiber coatings on new generation hybrid titanium composite by electrospinning

In this work, The hybrid hydroxyapatite (HaP), chitosan (CH) and graphene nanosheets (GNS) mixtures were applied by electrospinning on the surface of GNS and Si3N4 (SN) binary powder reinforced hybrid titanium (Ti) metal composites surface to improve composite biosurface functionallity. The surfaces of coated materials were characterized and antibacterial tests were carried on for their suitability in the industry by performing artificial body fluid tests. The hybrid nano fiber coatings formed a homogeneous structure on the composite. According to bioactivity tests and microstructure analysis, it was seen that HaP, which has the best results in the change of pH (pH= 11.80) values. The lowest mass change (0.0005 g) was observed on the 10th day of pure titanium. The highest mass change (0.0210 g) was obtained as on the HaP coated hybrid titanium composite. According to the antibacterial test result the hybrid nanofiber containing silver (Ag+) doped HaP on Ti composites showed the best antibacterial property aganist the E.coli. The fabricated electrospin coated hybrid composites can be a potantial candidate for dental, orthopedic implant applications and tissue engineering.

Comparison of different fiber coatings for distributed strain measurement in cementitious matrices

Distributed fiber optic strain measurement based on Rayleigh scattering has recently become increasingly popular in automotive and mechanical engineering for strain monitoring and in the construction industry, especially structural health monitoring. This technology enables the monitoring of strain along the entire fiber length. This article addresses integrating optical fibers of different coatings into the concrete matrix to measure the shrinkage deformations. However, previous studies do not give a clear statement about the strain transfer losses of fiber optic sensors in this application. In this context, three different coating types were investigated regarding their strain transfer. The fibers were integrated into fine-grained concrete prisms, and the shrinkage strain was compared with a precise dial gauge. The analysis shows a high correlation between the reference method and the fiber measurement, especially with the ORMOCER® coating. The acrylate coating used is also consistent in the middle area of the specimen but requires a certain strain introduction length to indicate the actual strain. The main result of this study is a recommendation for fiber coatings for shrinkage measurement in fine-grain concretes using the distributed fiber optic strain measurement. In addition, the advantages and disadvantages of the measurement method are presented.

Comparison of Different Fiber Coatings for Distributed Strain Measurement in Cementitious Matrices

The distributed fiber optic strain measurement based on Rayleigh scattering has recently become increasingly popular in automotive or mechanical engineering for strain monitoring and in the construction industry, especially structural health monitoring. This technology enables the monitoring of strain along the entire fiber length. This article addresses integrating optical fibers of different coatings into the concrete matrix to measure the shrinkage deformations. However, previous studies do not give a clear statement about the strain transfer losses of fiber optic sensors in this application. In this context, three different coating types were investigated regarding their strain transfer. The fibers were integrated into fine-grained concrete prisms, and the shrinkage strain was compared with a precise dial gauge. The analysis shows a high correlation between the reference method and the fiber measurement, especially with the Ormocer coating. The used acrylate coating is also consistent in the middle area of the specimen but requires a certain strain introduction length to indicate the actual strain. The main result of this study is a recommendation for fiber coatings for shrinkage measurement in fine-grain concretes using the distributed fiber optic strain measurement. In addition, the advantages and disadvantages of the measurement method are presented.

Tremolite–actinolite fiber coatings of sub-nanometer silica-rich particles in lungs from deceased Quebec miners

Tremolite–actinolite (TA) fibers from the lungs of deceased former Quebec mine workers were found to be coated with sub-nanometer particles. Qualitative chemical analyses were performed on the particles indicating that they were composed of silicon and oxygen. The crystal lattice structure of all amphibole minerals, including the TA series, is arranged as pairs of linear chains of SiO4 tetrahedra that are linked together to form double chains. Our observations of the TA fibers from miner’s lungs, made using a high-resolution transmission electron microscope, indicated that the tetrahedral silica chains were progressively split, forming dispersed sub-nanometer particles. The non-tetrahedral sites were removed at the surface of the TA fibers, presumably by the oxidation process involved in attempted phagocytosis, which also resulted in fragmentation of the tetrahedral chains. It was found that the silicon-rich particles (SRPs) were variable in diameter, consistent with fragments formed from the splitting of the tetrahedral chains. The TA fibers from lungs displayed coatings and linear interior zones of SRP parallel to the planes of longitudinal fiber splitting. The literature on very small nanoparticles is consistent with deep penetration of SRP into cell DNA interiors, oxidative stress, and carcinogenesis.