93 research outputs found
Compositional characteristics of the essential oil of Pimpinella anisum and Foeniculum vulgare grown in Serbia
The essential oils obtained by hydrodistillation from the mature fruits of Pimpinella anisum and Foeniculum vulgare were analyzed by GC-MS. The oil of aniseed was characterized by higher amounts of trans-anethole (96.80%) than fennel essential oil (83.43%). The isomer of trans-anethole, methyl chavicol (estragol) was also present in both plants, with 1.36% in fennel and 0.19% in aniseed. Apart from these two phenylpropanoids, nine sesquiterpenes and one monoterpene were present in essential oil of Pimpinella anisum, which constituted the other 3.01% of essential oil, but only γ-himachalene was present with more than 1%. In the case of fennel, eight monoterpenes constituted the other 15.21% of essential oil, and limonene and fenchone were present with contributions of 9.34 and 4.58%, respectively. © 2015 Institute of Botany and Botanical Garden Jevremovac, Belgrade
Crystal growth of K2TiGe3O9 in the glass
The kinetics and mechanism of isothermal crystal growth of K2TiGe3O9 from a glass of the same stoichiometric composition were studied. The crystal growth rate U = 1 x 10-11-1.27 x 10-10 m s-1 was experimentally determined in the temperature interval of t = 540-600°C. In the range of high undercooling, Δt=435-375°C, spherical crystals growing at (374 ± 19) kJ mol-1 was observed
Perspectives of the Apiaceae Hepatoprotective Effects - A Review
The liver has the crucial role in the regulation of various physiological processes and in the excretion of endogenous waste metabolites and xenobiotics. Liver structure impairment can be caused by various factors including microorganisms, autoimmune diseases, chemicals, alcohol and drugs. The plant kingdom is full of liver protective chemicals such as phenols, coumarins, lignans, essential oils, monoterpenes, carotenoids, glycosides, flavonoids, organic acids, lipids, alkaloids and xanthenes. Apiaceae plants are usually used as a vegetable or as a spice, but their other functional properties are also very important. This review highlights the significance of caraway, dill, cumin, aniseed, fennel, coriander, celery, lovage, angelica, parsley and carrot, which are popular vegetables and spices, but possess hepatoprotective potential. These plants can be used for medicinal applications to patients who suffer from liver damage
Compositional characteristics of the essential oil of Pimpinella anisum and Foeniculum vulgare grown in Serbia
The essential oils obtained by hydrodistillation from the mature fruits of Pimpinella anisum and Foeniculum vulgare were analyzed by GC-MS. The oil of aniseed was characterized by higher amounts of trans-anethole (96.80%) than fennel essential oil (83.43%). The isomer of trans-anethole, methyl chavicol (estragol) was also present in both plants, with 1.36% in fennel and 0.19% in aniseed. Apart from these two phenylpropanoids, nine sesquiterpenes and one monoterpene were present in essential oil of Pimpinella anisum, which constituted the other 3.01% of essential oil, but only γ-himachalene was present with more than 1%. In the case of fennel, eight monoterpenes constituted the other 15.21% of essential oil, and limonene and fenchone were present with contributions of 9.34 and 4.58%, respectively. © 2015 Institute of Botany and Botanical Garden Jevremovac, Belgrade
Hidden progress: broadband plasmonic invisibility
The key challenge in current research into electromagnetic cloaking is to
achieve invisibility over an extended bandwidth. There has been significant
progress towards this using the idea of cloaking by sweeping under the carpet
of Li and Pendry, with dielectric structures superposed on a mirror. Here, we
show that we can harness surface plasmon polaritons at a metal surface
structured with a dielectric material to obtain a unique control of their
propagation. We exploit this to control plasmonic coupling and demonstrate both
theoretically and experimentally cloaking over an unprecedented bandwidth
(650-900 nm). Our non-resonant plasmonic metamaterial allows a curved reflector
to mimic a flat mirror. Our theoretical predictions are validated by
experiments mapping the surface light intensity at the wavelength 800 nm
How the sialylation level of serum N-acetyl-beta-D-glucosaminidase A form in Type 1 diabetes mellitus influences their activity?
It was verified that the serum N-acetyl-beta-D-glucosaminidase (NAG) activity is elevated in diabetes, but there are no reports about changes in the sialic acid (SA) content in the carbohydrate parts of the NAG A form and its influence on the total changes in NAG activity in type 1 diabetes mellitus patients with and without secondary complications. The NAG A form was isolated from the serum of 81 insulin-dependent diabetes mellitus (IDDM) patients with and without secondary complications (retinopathy, polyneuropathy and nephropathy) and 25 healthy persons, and purified and characterised. The content of alpha-2,6-bound SA, the isoenzyme patterns of the purified A form, and the total NAG and A form activities were determined. In all diabetic groups, the sialylation levels of the A form were 2-3.5 times lower compared to control, while their acidities (fractions with pI 4.25-5.1) increased, particularly with progression of secondary complications. Total serum NAG activities and percentages of A form were significantly higher (P lt 0.001) in all diabetic groups and negatively correlated with the alpha-2,6-bound SA content of the A form. In addition, they decreased as secondary diabetic complications became more complex. The observed changes could be the consequence of structural changes in the A form due to significant increases in its acidity, i.e., negative charge, which originated from groups other than SA
Mode-matching in multiresonant plasmonic nanoantennas for enhanced second harmonic generation
Boosting nonlinear frequency conversion in extremely confined volumes remains
a key challenge in nano-optics, nanomedicine, photocatalysis, and
background-free biosensing. To this aim, field enhancements in plasmonic
nanostructures are often exploited to effectively compensate for the lack of
phase-matching at the nanoscale. Second harmonic generation (SHG) is, however,
strongly quenched by the high degree of symmetry in plasmonic materials at the
atomic scale and in nanoantenna designs. Here, we devise a plasmonic
nanoantenna lacking axial symmetry, which exhibits spatial and frequency mode
overlap at both the excitation and the SHG wavelengths. The effective
combination of these features in a single device allows obtaining unprecedented
SHG conversion efficiency. Our results shed new light on the optimization of
SHG at the nanoscale, paving the way to new classes of nanoscale coherent light
sources and molecular sensing devices based on nonlinear plasmonic platforms.Comment: 14 pages, 4 figure
Disposable sensors in diagnostics, food and environmental monitoring
Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities
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