The study of Dominican amber-bearing sediments from Siete Cañadas and La Cumbre with a discussion on their origin

The paper presents comprehensive mineralogical and geochemical characteristics of Dominican amber-bearing sediments from Siete Cañadas, Hato Mayor Province of the Eastern Mining District (EMD) in the Cordillera Oriental. The characteristics of rocks collected from the borehole in Siete Cañadas area (EMD) were compared with petrography of coaly shales from La Cumbre in the Northern Mining District (NMD). The mineralogy of the rocks was determined using transmitted and reflected light microscopy, scanning electron microscopy, Powder X-ray diffraction and Fourier Transform Raman Spectroscopy. Biomarker analyses by the gas chromatography–mass spectrometry were used to trace the genetic source and transformation stage of organic matter hosted in the core sediments. In this study, the characteristics of rocks from La Cumbre were supplemented with the petrographic data from our studies reported earlier. Based on the findings, it has been concluded that the basins in the investigated parts of the EMD and NMD regions were likely characterized by different, isolated palaeosettings. Transformation and maturation of terrigenous material were affected by locally occurring physicochemical conditions. In both amber deposits, the sedimentation of clastic and organic material proceeded in the presence of marine conditions. In case of the La Cumbre deposit (NMD area), the sedimentation underwent probably in the conditions of the lagoon environment, a shallow maritime lake or periodically flooded plain that facilitated organic matter decomposition and carbonation from meta-lignite to sub-bituminous coal (random reflectance of coal—Rro = 0.39%). In the Siete Cañadas (EMD region), the sedimentation took place in a shallow saltwater basin, where terrigenous material was likely mixed with material found in situ (fauna fossils, carbonate-group minerals) to form the mudstones enriched in bituminous substance of low maturity. The organic matter found in the rocks from both deposits is of mixed terrestrial/marine origin and was deposited in the presence of low oxygen concentration and reducing and/or dysoxic conditions.

Assessment of Biotechnologically Important Filamentous Fungal Biomass by Fourier Transform Raman Spectroscopy

Oleaginous filamentous fungi can accumulate large amount of cellular lipids and biopolymers and pigments and potentially serve as a major source of biochemicals for food, feed, chemical, pharmaceutical, and transport industries. We assessed suitability of Fourier transform (FT) Raman spectroscopy for screening and process monitoring of filamentous fungi in biotechnology. Six Mucoromycota strains were cultivated in microbioreactors under six growth conditions (three phosphate concentrations in the presence and absence of calcium). FT-Raman and FT-infrared (FTIR) spectroscopic data was assessed in respect to reference analyses of lipids, phosphorus, and carotenoids by using principal component analysis (PCA), multiblock or consensus PCA, partial least square regression (PLSR), and analysis of spectral variation due to different design factors by an ANOVA model. All main chemical biomass constituents were detected by FT-Raman spectroscopy, including lipids, proteins, cell wall carbohydrates, and polyphosphates, and carotenoids. FT-Raman spectra clearly show the effect of growth conditions on fungal biomass. PLSR models with high coefficients of determination (0.83–0.94) and low error (approximately 8%) for quantitative determination of total lipids, phosphates, and carotenoids were established. FT-Raman spectroscopy showed great potential for chemical analysis of biomass of oleaginous filamentous fungi. The study demonstrates that FT-Raman and FTIR spectroscopies provide complementary information on main fungal biomass constituents.

The Characteristics and Origin of Amber Deposits in the Dominican Republic

Mineralogical and geochemical characteristics of amber deposits located in the Dominican Republic, i.e., Hato Mayor Province of the Eastern Mining District (EMD) in the Cordillera Oriental, and Santiago Province of the Northern Mining District (NMD) in the Cordillera Septentrional were performed. The results of analyses of amber-bearing sediments collected from the borehole in Siete Cañadas area (EMD) were referenced to the petrological data obtained for the coaly shales from La Cumbre (NMD). The mineralogy of the rocks was described using transmitted and reflected light microscopy, scanning electron microscopy, Powder X-ray diffraction and Fourier Transform Raman Spectroscopy. Biomarker analyses by the gas chromatography-mass spectrometry were used to trace the genetic source and transformation stage of abundant organic matter hosted in the core sediments. Our findings indicated that basins in EMD and NMD regions were different isolated palaeosettings, in which under the influence of local physicochemical factors the terrigenous material was transformed and got maturated. In both amber deposits, the sedimentation of clastic and organic material proceeded in the presence of marine conditions. In case of the NMD area, the sedimentation underwent probably in the conditions of the lagoon environment, a shallow maritime lake or periodically flooded plain, that facilitated organic matter decomposition and carbonation from meta-lignite to sub-bituminous coal (random reflectance of coal - Rro = 0,39%). In the EMD region, the sedimentation took place in a deeper basin, where terrigenous material was likely mixed with material found in situ (fauna fossils, carbonate-group minerals) to form the mudstones enriched in bituminous substance of low maturity. The organic matter found in the rocks from both regions is of mixed terrestrial/marine origin and was deposited in the presence of low oxygen concentration and reducing and/or dysoxic conditions.

Polymers Sorption Properties towards Photosynthetic Pigments and Fungicides

In the present work, extraction with a solvent (cold acetone) was used to extract the assimilation pigments from spinach leaves. Then, the sorption capacity of selected plastics granules (polyvinyl chloride—PVC, polypropylene—PP, polyethylene—PE of different densities) was tested for the selective isolation of chlorophylls. Quantification of chlorophylls by HPLC (Zorbax Eclipse XDB-C18 column, the mobile phase: Acetonitrile/methanol/ethyl acetate 6:2:2, v/v) was based on chlorophyll-a content as the most common chlorophyll. The performed experiments prove that PVC containing electronegative chlorine exhibits favorable interactions toward chlorophyll by creating stable molecular complexes. The Fourier Transform Raman Spectroscopy (FT-Raman) and the molecular modeling were used to elucidate the structure of the created complexes. The optimal extraction requirements, the mass of sorbent, water-acetone ratio, time, and the composition of the elution solvent were all established. The optimized extraction conditions ensured a maximum extraction yield of chlorophylls of 98%. The chlorophyll-rich sorbent was re-extracted by acetone, leading to the recovery of 91% of chlorophylls in one step, adding the possibility of its re-use. The proposed effective and ecological method of obtaining the green dye from plants is cheap, simple, and efficient, avoiding organic solvents, utilizing the most widely used synthetic polymers in the world, being products difficult for utilization. The possibility to remove chosen fungicides cyprodinil, chlorothalonil, and thiabendazone from plant extract by PVC was also examined. The described method proposes a new application of synthetic polymers, which meets the criteria of sustainable green chemistry, simultaneously reaching the growing demand for pure natural compounds in the pharmaceutical and food industries.

Cobalt Sulfide as Photoelectrode of Photoelectrochemical Hydrogen Generation from Water

This study aimed to synthesize and characterize cobalt sulfide deposited on FTO by hydrothermal method and investigate its photoelectrochemical (PEC) water splitting performance. Cobalt sulfide thin films were produced by annealing at two different temperatures, namely, 400 and 500 °C. X-ray diffraction (XRD) and Fourier transform Raman spectroscopy were used to characterize the phase structure. Scanning electron microscopy was used to observe the morphology. Ultraviolet-visible spectroscopy and linear sweep voltammetry analyses were used to determine the thin-film band gap and evaluate the PEC water splitting performance, respectively. From the XRD and Raman analyses, all the samples produced consisted of mixed phases of Co3S4 and Co9S8. However, each sample contained different percentage phases. The sample annealed at 400 °C contained more Co9S8, whereas that annealed at 500 °C contained comparable amounts of Co3S4 and Co9S8. The morphologies of pre-annealed samples showed vertical flakes with diameters around 200-250 nm and flake thickness around 25-50 nm. When the temperature was increased from pre-annealing temperature to 400 and 500 °C, several flakes were destructed and formed spherical-like clusters. The Tauc plot from absorption analysis showed that the samples annealed at 400 and 500 °C produced similar band gaps at ~2.0 eV. The PEC performance analysis results show that annealing at 400 °C produced the highest photocurrent density of 10 µA/cm2 at a potential of -0.7 V.

Antibody CD133 Biofunctionalization of Ammonium Acryloyldimethyltaurate and Vinylpyrrolidone Co-Polymer-Based Coating of the Vascular Implants

Current vascular stents, such as drug eluting stents (DES), have some serious drawbacks, like in stent restenosis and thrombosis. Therefore, other solutions are sought to overcome these post-implantations complications. These include the strategy of biofunctionalization of the stent surface with antibodies that facilitate adhesion of endothelial cells (ECs) or endothelial progenitor cells (EPCs). Rapid re-endothelialization of the surface minimizes the risk of possible complications. In this study, we proposed ammonium acryloyldimethyltaurate/vinylpyrrolidone co-polymer-based surface (AVC), which was mercaptosilanized in order to expose free thiol groups. The presence of free thiol groups allowed for the covalent attachment of CD133 antibodies by disulfide bridges formation between mercaptosilanized surface and cysteine of the protein molecule thiol groups. Various examinations were performed in order to validate the procedure, including attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) and Fourier transform Raman spectroscopy (FT-Raman), atomic force microscopy (AFM) and scanning electron microscopy (SEM). By means of ATR-FTIR spectroscopy presence of the CD133 antibody within coating was confirmed. In vitro studies proved good biocompatibility for blood cells without induction of hemolytic response. Thus, proposed biofunctionalized CD133 antibody AVC surface has shown sufficient stability for adapting as cardiovascular implant coating and biocompatibility. According to conducted in vitro studies, the modified surface can be further tested for applications in various biological systems.

Protein Signatures to Trace Seafood Contamination and Processing

This review presents some applications of proteomics and selected spectroscopic methods to validate certain aspects of seafood traceability. After a general introduction to traceability and the initial applications of proteomics to authenticate traceability information, it addresses the application of proteomics to trace seafood exposure to some increasingly abundant emergent health hazards with the potential to indicate the geographic/environmental origin, such as microplastics, triclosan and human medicinal and recreational drugs. Thereafter, it shows the application of vibrational spectroscopy (Fourier-Transform Infrared Spectroscopy (FTIR) and Fourier-Transform Raman Spectroscopy (FT Raman)) and Low Field Nuclear Magnetic Resonance (LF-NMR) relaxometry to discriminate frozen fish from thawed fish and to estimate the time and temperature history of frozen fillets by monitoring protein modifications induced by processing and storage. The review concludes indicating near future trends in the application of these techniques to ensure seafood safety and traceability.

Improvement of mechanical properties of hydroxyapatite composites reinforced with i-Al64Cu23Fe13 quasicrystal

Mechanical behavior of hydroxyapatite-based composites (HAp) was studied as a function of the reinforcement concentration of the quasicrystalline (QC) Al64Cu23Fe13 alloy. The synthesis of the HAp matrix was carried out by sol-gel method, while the synthesis of the QC was performed by an arc furnace with a subsequent thermal treatment. The composites were made by powder metallurgy and cold compacted to form test pieces that were sintered with a constant flow of argon. The materials were characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and Fourier transform Raman spectroscopy. The study of mechanical strength was carried through compression tests. The biocompatibility of the composites was tested using an in-vitro cytotoxicity assay. The mechanical resistance of HAp/QC composites increased with the concentration of quasicrystalline reinforcement. Young’s modulus and compressive strength increased in 43% and 21%, respectively, with a 10 wt% QC reinforcement, which demonstrates an hybrid behaviour of the composite due to the inclusion of reinforcing particles in the pores of the matrix. This composite did not show cytotoxicity at any of the QC concentrations. A fabrication route is proposed as a fast, easy and high efficiency alternative for applications in the biomedical industry because of its high scalability potential.