Temperature optimisation
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Cannabis sativa L. is a plant belonging to the Cannabaceae family known primarily for its recreational use due to the psychoactive properties of Δ9-tetrahydrocannabinol (THC). Despite this, several compounds belonging to the category of phytocannabinoids have shown in recent years a number of potentially promising therapeutic effects that have increased the interest in the pharmaceutical field towards this plant. However, the content of these compounds is very variable and influenced by different factors, such as growing conditions and time of the year. An indication of the status and age of Cannabis samples is provided by the content of CBN, a minor phytocannabinoid and degradation product of other phytocannabinoids, including THC. In this research work an innovative, solid state analytical approach has been developed to observe and evaluate the variations in the content of two phytocannabinoids (CBN and CBD) in Cannabis-derived products over time. In order to simulate the ageing of the Cannabis samples, an artificially accelerated ageing procedure has been developed and optimised by using high temperatures. The analyses were carried out using an innovative ATR-FTIR method for solid state analysis, enabling direct analysis of a solid sample without any pretreatment phase. This study has allowed the development of an innovative analytical approach for the evaluation of the age and state of conservation of Cannabis samples and may be a useful tool both in the industrial, pharmaceutical and forensic fields.
- MeSH
- Cannabis * chemie MeSH
- časové faktory MeSH
- kanabidiol analýza chemie MeSH
- kanabinoidy * analýza chemie MeSH
- rostlinné extrakty chemie analýza MeSH
- spektroskopie infračervená s Fourierovou transformací metody MeSH
- stabilita léku MeSH
- tetrahydrokanabinol analýza chemie MeSH
- Publikační typ
- časopisecké články MeSH
Nitroalkane oxidases (NAOs) are flavoenzymes that catalyse the oxidation of nitroalkanes to their corresponding carbonyl compounds while producing nitrite anions. Herein, we present an artificial catalytic system using flavins or ethylene-bridged flavinium salts that works via an NAO-like process. Under conditions optimised in terms of solvent, base, temperature and oxygen pressure, primary nitroalkanes were transformed to aldehydes. In our system, aldehydes immediately reacted with other nitroalkane molecules to form β-nitroalcohols. The reduced flavin catalyst was re-oxidised by oxygen. An alternative mechanism towards β-nitroalcohols via 5-(2-nitrobutyl)-1,5-dihydroflavin was suggested through quantum chemical calculations and by trapping and characterising this dihydroflavin intermediate. Interestingly, 5-(2-nitrobutyl)-1,5-dihydroflavin is an analogue of the flavin adenine dinucleotide adduct previously observed in an NAO X-ray structure. In both mechanistic pathways, flavin-5-iminium species is formed by nitroalkanide addition to flavin. This process represents flavin-based umpolung of an original donor to an acceptor.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Electronic nicotine delivery systems (ENDS) generate an aerosol by vaporising e-liquids that usually consist of propylene glycol (PG), vegetable glycerine (VG), and other ingredients (water, nicotine, and flavours). The chemical and physical properties of these components have a significant effect on aerosol formation and must be identified in order to improve product attractiveness and assess the degree of health risks. AIM: The aim of this article is to provide a description of the composition of the e-liquid base and its impact on the physical properties of the liquid used and the behaviour of the aerosol generated and particles separately. METHODS: For this purpose, 46 articles were selected using a series of keywords. English- language publications were chosen. RESULTS: The impact of the PG/VG ratio on the physical properties of the e-liquid (boiling point, viscosity, volatility, hygroscopicity), aerosol emission characteristics (refractive index, light scattering coefficient, particle size distribution, concentration, emission of harmful compounds), vape attractiveness (taste, “throat-hit”, “cloud effect”), nicotine flux, coil temperature, and puff topography is presented. CONCLUSIONS: The PG/VG ratio is strongly correlated with the emission of carbonyls, which has adverse health effects and should be optimised. Furthermore, PG and VG also affect the other important characteristics of the aerosol generated by ENDS, which impact on both attractiveness and the consumption of harmful compounds. These findings could be considered for further research with the aim of improving electronic nicotine delivery systems as this can reduce levels of toxicants. This can be achieved by optimising the geometry of the components with respect to heating power and e-liquid.
INTRODUCTION: Organic molecules that interact with the cannabinoid receptors are called cannabinoids, which can be endogenous, natural or synthetic compounds. They possess similar pharmacological properties as produced by the plant, Cannabis sativa L. Before cannabinoids can be analysed, they need to be extracted from the matrices. OBJECTIVE: To review literature on the methods and protocols for the extraction of naturally occurring cannabinoids. METHODOLOGY: An extensive literature search was performed incorporating several databases, notably, Web of Knowledge, PubMed and Google Scholar, and other relevant published materials. The keywords used in the search, in various combinations, with cannabinoids and extraction being present in all combinations, were Cannabis, hemp, cannabinoids, Cannabis sativa, marijuana, and extraction. RESULTS: In addition to classical maceration with organic solvents, e.g. ethanol, pressurised solvent extraction, solvent heat reflux, Soxhlet extraction, supercritical fluid extraction, ultrasound-assisted extraction and microwave-assisted extraction, are routinely used nowadays for the extraction of cannabinoids from plant materials and cannabis consumer products. For the extraction of cannabinoids from biological samples, e.g. human blood, and also from food and beverages, and wastewater, solid-phase extraction and its variants, as well as liquid-liquid extraction are commonly used. Parameters for extraction can be optimised by response surface methodology or other mathematical modelling tools. There are at least six US patents on extraction of cannabinoids available to date. CONCLUSIONS: Irrespective of the extraction method, extraction temperature, extraction time and extraction pressure play a vital role in overall yield of extraction. Solvent polarity can also be an important factor in some extraction methods.
BACKGROUND: Pain and fever in the periparturient period can lead to prolonged farrowing and can slow down the recovery of the sow, which will have an effect on the vitality and survival of the piglets. This study investigated the use of orally administered Paracetamol (Pracetam- CEVA) in sows in the periparturient period. RESULTS: Mortality did not differ in piglets during the first week, or during total lactation (P > 0.10). No difference was found in weight or weight gain of the piglets during lactation. The coefficient of variation of piglet weight was smaller in the Paracetamol (Pm) group at day 7, day 14 and at weaning, but not at birth. So, the variation within litters was smaller in the Pm- treated sows, in comparison with the Control (C) litters. No difference in mean IgG concentration was found between treatments, but the coefficient of variation was too high (> 40) in 50% of the C litters and not in Pm litters. The Pm- treated sows lost less backfat than the C- sows. No effect was found on the body temperature of the sows, but fever was rare in both groups. CONCLUSION: Paracetamol results in less variation of body weight of piglets during lactation, seems to have a potential effect on the distribution of IgG within litters and has a positive effect on backfat loss. The effects of Paracetamol might be even more pronounced in farms with high piglet mortality (this farm only 8%) or with a high incidence of agalactia, fever after farrowing or piglet diarrhoea, which was not the case in this farm. Paracetamol is a promising product for increasing the welfare in lactating sows and optimising production in the farrowing stable.
- Publikační typ
- časopisecké články MeSH
Electron-deficient chlorine covalently immobilised on an amido group of hyaluronic acid (HA) can be potentially exceptional for applications requiring biodegradable and biocompatible polymers with enhanced antibacterial or antiviral activity. This expectation is supported by the assumption that a small amount of HA chloramide (HACl) is formed in the extracellular matrix under inflammatory conditions by a reaction of endogenous HA with hypochlorous acid (HClO) generated by a myeloperoxidase/H2O2/Cl- system. HACl synthesis optimisation showed significant limitations of HClO as an oxidative agent where only lower degrees of substitution (DS) was achieved. Commercially available oxidative agents based on chlorinated isocyanuric acid were successfully tested, producing the HA chain with almost entirely chlorinated amidic groups. The structure of the final HACl was thoroughly studied using advanced 2-dimensional NMR methodologies and LC/MS. Stability of HACl at different temperatures was monitored over 12 months. Preliminary antimicrobial and antiviral tests demonstrated the potential of HACl for applications in biomedicine.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- antifungální látky chemie farmakologie MeSH
- antivirové látky chemie farmakologie MeSH
- Bacteria účinky léků MeSH
- chloraminy chemie farmakologie MeSH
- halogenace MeSH
- houby účinky léků MeSH
- kyselina chlorná chemie MeSH
- kyselina hyaluronová chemie MeSH
- viry účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
Biological experiments involving isolated organs and tissues demand precise temperature monitoring and regulation. An automatic temperature control system was proposed and optimised on real isolated swine hearts and the prototype is described in this work. The traditional Langendorff apparatus consists of a heart holder, a reservoir of perfusion solution flowing to aortic cannula and a heating bath allowing passive heat transfer to the reservoir of perfusion solution. The commercial infrared camera FLIR T62101 was added to this basic set-up and used for very precise monitoring of the temperature kinetic of the organ and connected with an electronic feedback loop, which allowed real-time and precise regulation of heat transfer from the heating bath to the perfusion solution and in turn indirectly to the heart tissue. This provides real time control and active regulation of the myocardial tissue temperature. The infrared camera was tested in several modes and several variants of detection were optimised for ideal measurement of the region of interest of the ex vivo organ. The kinetics of the temperature changes and temperature stability of the tissue were recorded and calibrated by external electronic thermometers (type Pt100, inserted in tissue). The time lapse from the hang-up of the hypo termed organ (30 °C) until optimal warming (37 °C) was less than eight minutes in the final instrument prototype. The final stability of the 37 °C tissue temperature was approved; the temperature fluctuation of left ventricle tissue was characterised as 36.8 ± 0.5 °C. This upgraded traditional instrument could be used in specific preclinical and clinical transplantation and analytical projects in future.
- MeSH
- infračervené záření MeSH
- lidé MeSH
- preparace izolovaného srdce * metody MeSH
- terapeutické zahřívání metody přístrojové vybavení MeSH
- termoregulace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
A new β-galactosidase-producing bacterium KGP, isolated from the Bay of Bengal, was identified as Paracoccus marcusii through morphology, biochemistry and 16S rRNA sequencing. This study is the first report on the production of β-galactosidase from P. marcusii. The medium components for the high yield of β-galactosidase were optimised using response surface methodology (RSM). A set of 17 experiments consisting of three independent variables, viz. yeast extract, galactose and MgSO4, was employed. A second-order polynomial equation was used for the analysis of the response, and the optimum β-galactosidase yield was achieved using 12.5 g/L yeast extract, 12.5 g/L galactose and 12.5 mmol/L MgSO4. The predicted quadratic model was inferred to be significant from the F-value, P value and the lack of fit value. Optimisation of the media components resulted in a ninefold increase (560 Miller units) in β-galactosidase production. Furthermore, the hydrolysis and transgalactosylation efficiency of the crude β-galactosidase was assessed and the results showed that the lactose was successfully hydrolysed and transgalactosylated at an optimum temperature of 40 °C and 50 °C, respectively. Considering the overall yield and productivity, P. marcusii can be considered a candidate for the industrial production of β-galactosidase. This study provides an essential basis for the future production and use of the alkali-tolerant β-galactosidase from P. marcusii KGP.
- MeSH
- beta-galaktosidasa metabolismus MeSH
- bioreaktory MeSH
- fylogeneze MeSH
- galaktosa metabolismus MeSH
- hydrolýza MeSH
- koncentrace vodíkových iontů MeSH
- laktosa metabolismus MeSH
- oligosacharidy biosyntéza MeSH
- Paracoccus klasifikace genetika izolace a purifikace metabolismus MeSH
- RNA ribozomální 16S genetika MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Hibernating bats optimise the duration of torpor bouts and arousals in relation to hibernaculum microclimatic conditions and fat reserves. Clustering has significant physiological and ecological benefits, promoting successful hibernation of individuals. Such aggregations may help maintain optimal temperatures, allowing better energy utilisation than in solitarily bats. However, aroused bats in a cluster could conceivably disturb those still hibernating, starting an energy-demanding arousal process. Our study was conducted over two winters in two different hibernacula (cave and mine) in the Czech Republic, where Greater mouse-eared bats (Myotis myotis) have previously been diagnosed with white-nose syndrome. In 118 arousal episodes we recorded 193 individual arousals in which a warming phase was observed, 135 (69.9%) being cold arousals, where bats ceased increasing their body temperatures at ≤ 10 °C. The remaining arousals were standard normothermic arousals, where body (fur) surface temperatures reached > 20 °C. Cold arousals occurred during the mid- and late hibernation periods, suggesting they were a response to disturbance by a neighbour in the same cluster. Arousal cascades, where bats aroused in series, were rare (12.7%) and reached a maximum in mid-January. Our data suggest that Myotis bats prolong their torpor bouts using numerous cold arousals but few arousal cascades. Upon arrival of a bat, the clustered bats show tolerance to disturbing by conspecifics.
- MeSH
- arousal MeSH
- Chiroptera fyziologie MeSH
- chování zvířat MeSH
- hibernace * MeSH
- nízká teplota MeSH
- roční období MeSH
- strnulost MeSH
- tělesná teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
As management of respiratory distress syndrome (RDS) advances, clinicians must continually revise their current practice. We report the fourth update of "European Guidelines for the Management of RDS" by a European panel of experienced neonatologists and an expert perinatal obstetrician based on available literature up to the end of 2018. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, need for appropriate maternal transfer to a perinatal centre and timely use of antenatal steroids. Delivery room management has become more evidence-based, and protocols for lung protection including initiation of CPAP and titration of oxygen should be implemented immediately after birth. Surfactant replacement therapy is a crucial part of management of RDS, and newer protocols for its use recommend early administration and avoidance of mechanical ventilation. Methods of maintaining babies on non-invasive respiratory support have been further developed and may cause less distress and reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation using caffeine and, if necessary, postnatal steroids are also important considerations. Protocols for optimising general care of infants with RDS are also essential with good temperature control, careful fluid and nutritional management, maintenance of perfusion and judicious use of antibiotics all being important determinants of best outcome.
- MeSH
- kojenec MeSH
- konsensus MeSH
- lidé MeSH
- management nemoci MeSH
- neonatologové MeSH
- novorozenec nedonošený MeSH
- novorozenec MeSH
- plicní surfaktanty terapeutické užití MeSH
- syndrom respirační tísně novorozenců terapie MeSH
- trvalý přetlak v dýchacích cestách metody MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- směrnice pro lékařskou praxi MeSH
- Geografické názvy
- Evropa MeSH
