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991.
Joanna Bojarska Martin Breza Milan Remko Malgorzata Czyz Anna Gajos-Michniewicz Micha&#x; Zimecki Krzysztof Kaczmarek Izabela D. Madura Jakub M. Wojciechowski Wojciech M. Wolf 《International journal of molecular sciences》2022,23(13)
Short peptides have great potential as safe and effective anticancer drug leads. Herein, the influence of short cyclic peptides containing the Pro-Pro-Phe-Phe sequence on patient-derived melanoma cells was investigated. Cyclic peptides such as cyclo(Leu-Ile-Ile-Leu-Val-Pro-Pro-Phe-Phe-), called CLA, and cyclo(Pro-homoPro-β3homoPhe-Phe-), called P11, exert the cytotoxic and the cytostatic effects in melanoma cells, respectively. CLA was the most active peptide as it reduced the viability of melanoma cells to 50% of control at about 10 µM, whereas P11 at about 40 µM after 48 h incubation. Interestingly, a linear derivative of P11 did not induce any effect in melanoma cells confirming previous studies showing that cyclic peptides exert better biological activity compared to their linear counterparts. According to in silico predictions, cyclic tetrapeptides show a better pharmacokinetic and toxic profile to humans than CLA. Notably, the spatial structure of those peptides containing synthetic amino acids has not been explored yet. In the Cambridge Structural Database, there is only one such cyclic tetrapeptide, cyclo((R)-β2homoPhe-D-Pro-Lys-Phe-), while in the Protein Data Bank—none. Therefore, we report the first crystal structure of cyclo(Pro-Pro-β3homoPhe-Phe-), denoted as 4B8M, a close analog of P11, which is crucial for drug discovery. Comparative molecular and supramolecular analysis of both structures was performed. The DFT findings revealed that 4B8M is well interpreted in the water solution. The results of complex Hirshfeld surface investigations on the cooperativity of interatomic contacts in terms of electrostatic and energetic features are provided. In short, the enrichment ratio revealed O…H/H…O and C…H/H…C as privileged intercontacts in the crystals in relation to basic and large supramolecular H-bonding synthon patterns. Furthermore, the ability of self-assemble 4B8M leading to a nanotubular structure is also discussed. 相似文献
992.
993.
Subhankar Mandal Srishti Kumari Milan Kumar Umaprasana Ojha 《Advanced functional materials》2021,31(26):2100251
To synthesize hydrogels that possess tensile strength and modulus together in MPas along with extensibility at high equilibrium water content (≥90 wt%) is challenging but important from the application perspective. Especially, such hydrogel compositions are useful for fabricating flexible electronics devices for subsea applications, where underwater risk-free implementation and optimum device performance at low temperature (≈0 °C) and high hydrostatic pressure (≤20 bar) conditions is desirable. The high water content of hydrogel is necessary to facilitate ion transportation, and mechanical strength is desirable to maintain a stable electrode–electrolyte interface under load. In this study, supplementary networking of an interpenetrating polymer system strategy is utilized to develop ionic hydrogels with tensile strength and Young's modulus values up to 2 and 1.67 MPa, respectively, at high equilibrium water content value up to 96%. Cost-effective, durable, rechargeable, and flexible batteries are fabricated using the Zn & Li ion soaked hydrogel as solid electrolyte without barrier. These batteries display minimal loss in capacity when immersed in water, deformed, exposed to flame, put under high load, and operated under low-temperature conditions suggesting the viability for subsea application. 相似文献
994.
Vaisakh C. Paingad Jan Kunc Martin Rejhon Ivan Rychetský Ivan Mohelský Milan Orlita Petr Kužel 《Advanced functional materials》2021,31(45):2105763
The control of carrier transport by electrical, chemical, or optical Fermi level tuning is central to graphene electronics. Here, an optical pump—terahertz (THz) probe spectroscopy—is applied to investigate ultrafast sheet conductivity dynamics in various epitaxially grown graphene layers representing a large variety of carbon allotropes, including H2 intercalated films. The graphene layers display a prominent plasmonic response connected with induced THz transparency spectra on ultrashort timescale. It is generally believed that the plasmonic excitations appear due to wrinkles, and substrate terraces that bring about natural confinement potentials. It is shown that these potentials act within micrometer-sized domains with essentially isotropic character. The measured ultrafast dynamics are entirely controlled by the quasi-Fermi level of laser-excited carriers through their temperature. The photocarriers undergo a disorder-enabled super-collision cooling process with an initial picosecond transfer of the optically deposited heat to the lattice followed by a sub-nanosecond relaxation governed by the lattice cooling. The transient spectra is described by a two-temperature Drude-Lorentz model revealing the ultrafast evolution of the carrier temperature and chemical potential and providing crucial material parameters such as Fermi energy, carrier mobility, carrier confinement length, and disorder mean free path. 相似文献
995.
996.
Awadhesh Kumar Puja Archana Panda Milan Kumar Lal Umakanta Ngangkham Chandrasekhar Sahu Khela Ram Soren Hata Nath Subudhi Sanghamitra Samantaray Srigopal Sharma 《Starch - St?rke》2020,72(9-10):1900081
Rice exhibits relatively high glycemic index (GI) value compared to other carbohydrate rich foods. Eating rice as a staple food and leading sedentary life style may lead to obesity and type-II diabetes. National Rice Research Institute (ICAR-NRRI), Cuttack, India released varieties were analyzed for low GI and high resistant starch (RS) content. Large variations were observed in the GI (57.5–76.4) and RS content (0.28–2.94%) among the varieties. The rice Shaktiman had the lowest GI (57.50) with relatively high RS content (2.11%) while Gayatri had the highest RS (2.94%) with relatively low GI (60.31) value. Addition of pigeon pea to rice resulted in lowering of GI and increased RS content compared to other pulses. Addition of ghee (clarified butter) to rice during cooking resulted in lowering of GI and increase in RS content. The effect was not so pronounced with vegetable oils. Addition of vegetables like fenugreek and cauliflower to rice caused much more lowering of GI as compared to other vegetables. The findings emphasize the importance of identifying and developing rice with low GI and high RS content. This also highlights the importance of formulating food combinations of rice with other edible commodities that suit diabetics. 相似文献
997.
998.
Peter Gajdoš Jaroslav Hambalko Jean-Marc Nicaud Milan Čertík 《Yeast (Chichester, England)》2020,37(1):141-147
The 3-acetyl-1,2-diacylglycerols (acTAGs) are the molecules that are structurally similar to triacylglycerols (TAGs). They are naturally produced by plants of the family Celastraceae and animals such as Cervus nippon and Eurosta solidaginis. The presence of acetate in the sn–3 position of the glycerol backbone confers advantages to these compounds, for example, lower viscosity and calorific value compared to classical TAGs. In this work, the gene EeDAcT, which encodes diacylglycerol acetyltransferase in a species of bush (Euonymus europaeus), was overexpressed in strains Po1d (capable of accumulating storage lipids) and JMY1877 (incapable of accumulating storage lipids) of Yarrowia lipolytica, to test the activity of the gene EeDAcT and the production of acTAGs in oleaginous and nonoleaginous genetic backgrounds. It was observed that both the strains containing the gene EeDAcT (YL33 and YL35 for Po1d and JMY1877 strains, respectively) produced acTAGs. The strain YL33 accumulated up to 20% intracellular lipids, 20% of which was acTAGs, and 40% was TAGs. On the other hand, the strain YL35, which showed interrupted TAGs accumulation, produced up to 10% acTAGs as the only storage lipid. Unfortunately, the quantity of acTAGs produced in YL35 was insignificant, as the overall lipid accumulated in the strain was not more than 4% of the biomass. The fatty acid profile of acTAGs produced by the YL33 strain was remarkably similar to TAGs, and both of these structures were rich in oleic (45%) and palmitic (25%) acids. 相似文献
999.
Xeni Deligianni Daniel Jirák Zuzana Berková Milan Hájek Klaus Scheffler Oliver Bieri 《Magma (New York, N.Y.)》2014,27(4):329-337
Object
In vivo magnetic resonance imaging (MRI) of iron-labeled pancreatic islets (PIs) transplanted into the liver is still challenging in humans. The aim of this study was to develop and evaluate a double contrast method for the detection of PIs labeled with superparamagnetic iron oxide (SPIO) nanoparticles.Materials and methods
A double-echo three-dimensional (3D) spoiled gradient echo sequence was adapted to yield a sub-millisecond first echo time using variable echo times and highly asymmetric Cartesian readout. Positive contrast was achieved by conventional and relative image subtraction. Experiments for cell detection efficiency were performed in vitro on gelatin phantoms, in vivo on a Lewis rat and on a patient 6 months after PI transplantation.Results
It was demonstrated that the proposed method can be used for the detection of transplanted PIs with positive contrast in vitro and in vivo. For all experiments, relative subtraction yielded comparable and in some cases better contrast than conventional subtraction. For the first time, positive contrast imaging of transplanted human PIs was performed in vivo in patients.Conclusion
The proposed method allows 3D data acquisition within a single breath-hold and yields enhanced contrast-to-noise ratios of transplanted SPIO labeled pancreatic islets relative to negative contrast images, therefore providing improved identification. 相似文献1000.
Petr Baldrian V ra Merhautov Ji&#x;í Gabriel Franti&#x;ek Nerud Pavel Stopka Martin Hrubý Milan J. Bene&#x; 《Applied catalysis. B, Environmental》2006,66(3-4):258-264
Heterogeneous catalysts based on magnetic mixed iron oxides (MO·Fe2O3; M: Fe, Co, Cu, Mn) were used for the decolorization of several synthetic dyes (Bromophenol Blue, Chicago Sky Blue, Cu Phthalocyanine, Eosin Yellowish, Evans Blue, Naphthol Blue Black, Phenol Red, Poly B-411, and Reactive Orange 16). All the catalysts decomposed H2O2 yielding highly reactive hydroxyl radicals, and were able to decolorize the synthetic dyes. The most effective catalyst FeO·Fe2O3 (25 mg mL−1 with 100 mmol L−1 H2O2) produced more than 90% decolorization of 50 mg L−1 Bromophenol Blue, Chicago Sky Blue, Evans Blue and Naphthol Blue Black within 24 h. The fastest decomposition proceeded during the first hour of the reaction. In addition to dye decolorization, all the catalysts also caused a significant decrease of chemical oxygen demand (COD). Individual catalysts were active in the pH range 2–10 depending on their structure and were able to perform sequential catalytic cycles with low metal leaching. 相似文献