Search results for "General. Including alchemy"
showing 9 items of 9 documents
Three Spirostanol Glycosides from the Seeds of Hyoscyamus Niger L.
2006
Three steroidal glycosides of spirostane series have been isolated from the seeds of Hyoscyamus niger L.(Solanaceae). Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods including one-dimensional, two-dimensional NMR and MS analysis. In the genus Hyoscyamus the given compounds have been found out for the first time.
Caffeine as a Gelator
2016
Caffeine (a stimulant) and ethanol (a depressant) may have opposite effects in our body, but under in vitro conditions they can “gel” together. Caffeine, being one of the widely used stimulants, continued to surprise the scientific community with its unprecedented biological, medicinal and physicochemical properties. Here, we disclose the supramolecular self-assembly of anhydrous caffeine in a series of alcoholic and aromatic solvents, rendering a highly entangled microcrystalline network facilitating the encapsulation of the solvents as illustrated using direct imaging, microscopy analysis and NMR studies. Peer reviewed
GLYCOSIDES FROM LINARIA VULGARIS MILL
2008
A new flavonol glycoside, 5,4′-dimethylkaempferol 3-O-β-D-(6′′-α-Lrhamnopyranosyl) -glucopyranoside, together with three known compounds were isolated from the n-butanolic soluble fraction of underground and aerial parts of Linaria vulgaris Mill, collected on the territory of Moldova. The characterisation of these compounds was achieved by various chromatographic and spectroscopic methods (IR, UV, 13C-NMR, 1H-NMR and MS).
Physicochemical and Rheological Characterization of Different Low Molecular Weight Gellan Gum Products and Derived Ionotropic Crosslinked Hydrogels
2021
A series of four different low molecular weight gellan gum products was obtained by alkaline hydrolysis with the aim to investigate the impact of the molecular weight on the rheological properties of the polysaccharide aqueous dispersions and on the physicochemical characteristics of derived ionotropic crosslinked hydrogels. In particular, thermo-rheological analysis was conducted on aqueous dispersions to study the influence of molecular weight on the thermogelation properties typical of the native polysaccharide while strain sweep experiments were conducted to establish if aqueous dispersion shows a viscoelastic behavior. The effect of different Ca2+ on the rheological properties of hydro…
Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry
2021
Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-se…
Poly(N-isopropylacrylamide) and Copolymers: A Review on Recent Progresses in Biomedical Applications.
2017
The innate ability of poly(N-isopropylacrylamide) (PNIPAAm) thermo-responsive hydrogel to copolymerize and to graft synthetic polymers and biomolecules, in conjunction with the highly controlled methods of radical polymerization which are now available, have expedited the widespread number of papers published in the last decade—especially in the biomedical field. Therefore, PNIPAAm-based hydrogels are extensively investigated for applications on the controlled delivery of active molecules, in self-healing materials, tissue engineering, regenerative medicine, or in the smart encapsulation of cells. The most promising polymers for biodegradability enhancement of PNIPAAm hydrogels are probably…
Photocrosslinked Dextran-Based Hydrogels as Carrier System for the Cells and Cytokines Induce Bone Regeneration in Critical Size Defects in Mice
2018
Modified biomaterials have for years been the focus of research into establishing new bone substitutes. In our preceding in vitro study employing different cell cultures, we developed chemically and mechanically characterized hydrogels based on photocrosslinkable dextran derivatives and demonstrated their cytocompatibility and their beneficial effects on the proliferation of osteoblasts and endothelial cells. In the present in vivo study, we investigate photocrosslinked dextran-based hydrogels in critical size defects in mice to evaluate their potential as carrier systems for cells or for a specific angiogenesis enhancing cytokine to induce bone formation. We could demonstrate that, with op…
WASTE DUMPS IN LATVIA: FORMER LANDFILLING, CONSEQUENCES AND POSSIBLE RECULTIVATION
2012
Particular attention in this article is paid to the research of two waste dumps in the capital city of Latvia – Riga, which are planned to be re-cultivated in the nearest future and one site, which is former toxic hazardous soil dump site, where the remediation of site is of priority need. The present study is giving a general overview of contamination level in two waste dumps in Riga, which were made in the period from 50-ties to 70-ties of the 20th century, also the case of hazardous soil dump site formed in a period of more than 100 years is described. Planned actions as well as direct remediational technologies to reduce the poisonous impact to the urban environment and the role of re-c…
Functionalized Poly(N-isopropylacrylamide)-Based Microgels in Tumor Targeting and Drug Delivery
2021
Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the f…