排序方式: 共有39条查询结果,搜索用时 0 毫秒
31.
Taja
itek Dragana Bjeli Petra Kotnik Andrej Golle Staa Jurgec Uro Poto
nik
eljko Knez Matja Fingar Ivan Krajnc Igor Krajnc Maa Knez Marevci 《Molecules (Basel, Switzerland)》2022,27(22)
The prevention and treatment of skin diseases remains a major challenge in medicine. The search for natural active ingredients that can be used to prevent the development of the disease and complement treatment is on the rise. Natural extracts of ginger and hemp offer a wide range of bioactive compounds with potential health benefits. This study evaluates the effectiveness of hemp and ginger extract as a supportive treatment for skin diseases. It reports a synergistic effect of hemp and ginger extract. The contents of cannabinoids and components of ginger are determined, with the highest being CBD (587.17 ± 8.32 µg/g) and 6-gingerol (60.07 ± 0.40 µg/g). The minimum inhibitory concentration for Staphylococcus aureus (156.5 µg/mL), Escherichia coli (625.2 µg/mL) and Candida albicans (78.3 µg/mL) was also analyzed. Analysis of WM-266-4 cells revealed the greatest decrease in metabolic activity in cells exposed to the extract at a concentration of 1.00 µg/mL. Regarding the expression of genes associated with cellular processes, melanoma aggressiveness, resistance and cell survival, a significant difference was found in the expression of ABCB5, CAV1 and S100A9 compared with the control (cells not exposed to the extract). 相似文献
32.
The classic experimental modal analysis (EMA) is a well-known procedure for determining the modal parameters. The less frequently used strain EMA is based on a response measurement using strain sensors. The results of a strain EMA are the modal parameters, where in addition to the displacement mode shapes the strain mode shapes are also identified. The strain EMA can be used for an experimental investigation of a stress–strain distribution without the need to build a dynamical model. It can also be used to determine the modal parameters when, during modal testing, a motion sensor cannot be used and so a strain sensor is used instead. The displacement and strain mode shapes that are determined with the strain EMA are not mass normalized (scaled with respect to the orthogonality properties of the mass-normalized modal matrix), and therefore some dynamical properties of the system cannot be obtained. The mass normalization can be made with the classic EMA, which requires the use of a motion sensor. In this research a new approach to the mass normalization in the strain EMA, without using a motion sensor, is presented. It is based on the recently introduced mass-change structural modification method, which is used for the mass normalization in an operational modal analysis. This method was modified in such a way that it can be used for the mass normalization in the strain EMA. The mass-normalized displacement and strain mode shapes were obtained using a combination of the proposed approach and the strain EMA. The proposed approach was validated on real structures (beam and plate). 相似文献
33.
Probably the most popular algorithm for unconstrained minimization for problems of moderate dimension is the Nelder-Mead algorithm
published in 1965. Despite its age only limited convergence results exist. Several counterexamples can be found in the literature
for which the algorithm performs badly or even fails. A convergent variant derived from the original Nelder-Mead algorithm
is presented. The proposed algorithm's convergence is based on the principle of grid restrainment and therefore does not require
sufficient descent as the recent convergent variant proposed by Price, Coope, and Byatt. Convergence properties of the proposed
grid-restrained algorithm are analysed. Results of numerical testing are also included and compared to the results of the
algorithm proposed by Price et al. The results clearly demonstrate that the proposed grid-restrained algorithm is an efficient
direct search method. 相似文献
34.
35.
Gårdfeldt K Horvat M Sommar J Kotnik J Fajon V Wängberg I Lindqvist O 《Analytical and bioanalytical chemistry》2002,374(6):1002-1008
A comparison of manual procedures for measurements of dissolved gaseous mercury (DGM) in seawater was accomplished. The experiments were performed on board the Italian research vessel Urania during July 2000 as a subtask in the CNR "Med-Oceanor Project 2000". Water samples for DGM were collected by Go-Flo bottles and subsequently analysed for DGM on board the ship. Determinations of DGM were made in parallel by two groups using different analytical routines. The two sets of data obtained compare favourably. Based on the fieldwork and an additional laboratory study, analytical procedures are discussed and an optimised method to determine DGM is presented. In addition, a method for automated in situ measurements of DGM positioned in the water body was tested. This method has the potential to simplify studies of DGM dynamics, that is variation in concentration as a function of water temperature and solar radiation etc. 相似文献
36.
Tadej Stropnik 《Tetrahedron letters》2008,49(11):1729-1733
A regioselective method for the bromination of phenols, ethers and anilines using a ZrBr4/diazene mixture is described. The reaction takes place under mild reaction conditions and the bromine atom adds first at the para unsubstituted position with respect to the OH, OR or NR2 group of the activated aromatic substrate. Less reactive compounds such as toluene, phenyl acetate, benzonitrile and trifluoromethylbenzene remain intact under the same conditions. 相似文献
37.
The influence of medium conductivity on electropermeabilization and survival of cells in vitro. 总被引:9,自引:0,他引:9
G Pucihar T Kotnik M Kanduser D Miklavcic 《Bioelectrochemistry (Amsterdam, Netherlands)》2001,54(2):107-115
Electropermeabilization and cell death caused by the exposure to high voltage electric pulses depends on the parameters of pulses, as well as the composition of the extracellular medium. We studied the influence of extracellular conductivity on electropermeabilization and survival of cells in vitro. For this purpose, we used a physiological medium with a conductivity of 1.6 S/m and three artificial media with conductivities of 0.14, 0.005, and 0.001 S/m. Measurements of pH, osmolarity, and cell diameter were made to estimate possible side effects of the media on the cells. Our study shows that the percentage of surviving cells increases with the decreasing medium conductivity, while the percentage of electropermeabilized cells remains unaffected. Our results show that cell survival in experiments involving electropermeabilization can be improved by decreasing the medium conductivity. To provide an interpretation of experimental results, we have theoretically estimated the resting transmembrane voltage, the induced transmembrane voltage, the time constant of the voltage inducement, and heating of the cell suspension for each of the media used. These calculations imply that for accurate interpretation of experimental results, both the induced and the resting transmembrane voltage must be considered, taking into account the conductivity and the ionic composition of the extracellular medium. 相似文献
38.
Tadej Kotnik. 《Mathematics of Computation》2008,77(263):1713-1723
The paper describes a computational estimation of the constant characterizing the bounds of . It is known that as with , while the truth of the Riemann hypothesis would also imply that . In the range , two sets of estimates of are computed, one for increasingly small minima and another for increasingly large maxima of . As increases, the estimates in the first set rapidly fall below and gradually reach values slightly below , while the estimates in the second set rapidly exceed and gradually reach values slightly above . The obtained numerical results are discussed and compared to the implications of recent theoretical work of Granville and Soundararajan.
39.
This paper presents a new hybrid global optimization method referred to as DESA. The algorithm exploits random sampling and
the metropolis criterion from simulated annealing to perform global search. The population of points and efficient search
strategy of differential evolution are used to speed up the convergence. The algorithm is easy to implement and has only a
few parameters. The theoretical global convergence is established for the hybrid method. Numerical experiments on 23 mathematical
test functions have shown promising results. The method was also integrated into SPICE OPUS circuit simulator to evaluate
its practical applicability in the area of analog integrated circuit sizing. Comparison was made with basic simulated annealing,
differential evolution, and a multistart version of the constrained simplex method. The latter was already a part of SPICE
OPUS and produced good results in past research. 相似文献