Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Heliyon ; 8(2): e08843, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35146163

ABSTRACT

Many researchers address the benefits of using methodologies, standards, but they rarely go beyond the direct effects, and get to the ownership. The owner is one of the key participants in project management. This research aims to explore a possible association between the methodologies, standards applied in organizations, and owner's value. The data set serves as a base of the statistical analysis, where the respondents are employees working in a project management environment. The complex analysis of this study justified a significant relationship between standards and methodologies, and the creation of owner's value. Therefore, this finding could be employed to assess the chances of creating owner's value, e.g., in rapid evaluation methods in project management. Such a justified relationship can be used not only in project management.

2.
Sci Rep ; 11(1): 8951, 2021 04 26.
Article in English | MEDLINE | ID: mdl-33903673

ABSTRACT

The use of cannabidiol (CBD) in electronic cigarettes is widespread. Previously, it was reported that CBD is partly transformed to THC in case smoking as a cigarette, however, the pyrolysis of this compound has not been assessed extensively. The aim of our study was to investigate the effect of temperature on the composition of pyrolysis products of CBD. The experiments were performed in the typical operating temperature range of e-cigarettes (250-400 °C) and at 500 °C under both inert and oxidative conditions, and the pyrolysis products were identified and quantified by GC-MS. Depending on the temperature and atmosphere, 25-52% of CBD was transformed into other chemical substances: Δ9-THC, Δ8-THC, cannabinol and cannabichromene were the predominant pyrolysates in both conditions, all formed by cyclization reaction. THC was the main pyrolysis product at all temperatures under both oxidative and inert conditions. Our results point out that CBD in e-cigarettes can be considered as a precursor of THC, thus it bears all the dangers related to this psychoactive compound. Our findings are fundamental contributions to the safety profile of CBD-based e-cigarettes.


Subject(s)
Cannabidiol/chemistry , Cannabinoids , Dronabinol , Electronic Nicotine Delivery Systems , Cannabinoids/analysis , Cannabinoids/chemistry , Dronabinol/analysis , Dronabinol/chemistry , Pyrolysis
3.
Sci Rep ; 10(1): 8696, 2020 05 26.
Article in English | MEDLINE | ID: mdl-32457467

ABSTRACT

Amorphous calcium carbonate (ACC) is a precursor of crystalline calcium carbonates that plays a key role in biomineralization and polymorph evolution. Here, we show that several bacterial strains isolated from a Hungarian cave produce ACC and their extracellular polymeric substance (EPS) shields ACC from crystallization. The findings demonstrate that bacteria-produced ACC forms in water-rich environment at room temperature and is stable for at least half year, which is in contrast to laboratory-produced ACC that needs to be stored in a desiccator and kept below 10 °C for avoiding crystallization. The ACC-shielding EPS consists of lipids, proteins, carbohydrates and nucleic acids. In particular, we identified large amount of long-chain fatty acid components. We suggest that ACC could be enclosed in a micella-like formula within the EPS that inhibits water infiltration. As the bacterial cells lyse, the covering protective layer disintegrates, water penetrates and the unprotected ACC grains crystallize to calcite. Our study indicates that bacteria are capable of producing ACC, and we estimate its quantity in comparison to calcite presumably varies up to 20% depending on the age of the colony. Since diverse bacterial communities colonize the surface of cave sediments in temperate zone, we presume that ACC is common in these caves and its occurrence is directly linked to bacterial activity and influences the geochemical signals recorded in speleothems.


Subject(s)
Bacteria/metabolism , Calcium Carbonate/metabolism , Bacillus/metabolism , Bacteria/classification , Bacteria/genetics , Calcium Carbonate/chemistry , Crystallization , Microscopy, Electron, Scanning , Phylogeny , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/metabolism , Spectroscopy, Fourier Transform Infrared , Stenotrophomonas maltophilia/metabolism , Temperature , Water/chemistry
4.
C R Biol ; 334(11): 812-23, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22078738

ABSTRACT

The efficiency of enzymatic hydrolysis of lignocellulses can be increased by addition of surfactants and polymers, such as poly(ethylene glycol) (PEG). The effect of PEG addition on the cellulase adsorption was tested on various steam pretreated lignocellulose substrates (spruce, willow, hemp, corn stover, wheat straw, sweet sorghum bagasse). A positive effect of PEG addition was observed, as protein adsorption has decreased and free enzyme activities (FP, ß-glucosidase) have increased due to the additive. However, the degree of enhancement differed among the substrates, being highest on steam pretreated spruce. Results of lignin analysis (pyrolysis-GC/MS, (31)P NMR) suggest that the effect of PEG addition is in connection with the amount of unsubstituted phenolic hydroxyl groups of lignin in the substrate. Adsorption experiments using two commercial enzyme preparations, Celluclast 1.5L (Trichoderma reesei cellulase) and Novozym 188 (Aspergillus niger ß-glucosidase) suggested that enzyme origins affected on the adsorptivity of ß-glucosidases.


Subject(s)
Enzymes/chemistry , Lignin/chemistry , Polyethylene Glycols/chemistry , Adsorption , Carboxylic Acids/analysis , Chromatography, High Pressure Liquid , Filtration , Gas Chromatography-Mass Spectrometry , Hot Temperature , Hydrolysis , Magnetic Resonance Spectroscopy , Plant Proteins/analysis , Plants/chemistry , Steam , beta-Glucosidase/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...