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951.
Achraf Ammar Bassem Bouaziz Khaled Trabelsi Jordan M Glenn Piotr Zmijewski Patrick Müller Hamdi Chtourou Mohamed Jmaiel Karim Chamari Tarak Driss Anita Hkelmann 《Biology of sport / Institute of Sport》2021,38(3):391
Although recognized as effective measures to curb the spread of the COVID19 outbreak, social distancing and home confinement have generated a mental health burden with older adults who are considered to be more vulnerable to psychosocial strains. To date, the application of digital technologies in response to COVID-19 pandemic has been narrowed to public-health needs related to containment and mitigation. However, information and communications technology (ICT)-based initiatives directed toward prediction and prevention of psychosocial support are still limited. Given the power of digital health solutions to allow easy and accurate characterization and intervention for health and disease, as well as to flatten the COVID19 incidence curves in many countries, our ECLB-COVID19 consortium is highlighting the importance of providing innovative ICT-based solutions (ICT-COVID-Companion) to improve elderly physical and mental health, thereby preventing/dampening psychosocial strain during pandemics. Based on innovative approaches (e.g., emotional/social computing, open social platform, interactive coaching, gamification, fitness-tracker, internet of things) and smart digital solutions (smartwatch/smartphone), smart companions must provide safe personalised physical, mental and psychosocial health surveillance. Additionally, by delivering personalised multi-dimension crisis-oriented health recommendations, such innovative crisis-oriented solutions would help (i) facilitate a user’s adherence to active and healthy confinement lifestyle (AHCL), (ii) achieve a rapid psychosocial recovery in case of depression issues and (iii) enhance preparedness for eventual future pandemics. 相似文献
952.
953.
Agnieszka Sujak Janina Gabrielska Piotr Mazurek Wies?aw I. Gruszecki 《生物化学与生物物理学报:生物膜》2005,1712(1):17-28
Polar carotenoid pigment - canthaxanthin - has been found to interfere with the organization of biological membranes, in particular of the retina membranes of an eye of primates. The organization of lipid membranes formed with dipalmitoylphosphatidylcholine (DPPC) and egg yolk phosphatidylcholine containing canthaxanthin was studied by means of several techniques including: electronic absorption spectroscopy, linear dichroism, X-ray diffractometry, 1H-NMR spectroscopy and FTIR spectroscopy. It appears that canthaxanthin present in the lipid membranes at relatively low concentration (below 1 mol% with respect to lipid) modifies significantly physical properties of the membranes. In particular, canthaxanthin (i) exerts restrictions to the segmental molecular motion of lipid molecules both in the headgroup region and in the hydrophobic core of the bilayer, (ii) promotes extended conformation of alkyl lipid chains, (iii) modifies the surface of the lipid membranes (in particular in the gel state, Lβ´) and promotes the aggregation of lipid vesicles. It is concluded that canthaxanthin incorporated into lipid membranes is distributed among two pools: one spanning the lipid bilayer roughly perpendicularly to the surface of the membrane and one parallel to the membrane, localized in the headgroup region. The population of the horizontal fraction increases with the increase in the concentration of the pigment in the lipid phase. Such a conclusion is supported by the linear dichroism analysis of the oriented lipid multibilayers containing canthaxanthin: The mean angle between the dipole transition moment and the axis normal to the plane of the membrane was determined as 20 ± 3° at 0.5 mol% and 47 ± 3° at 2 mol% canthaxanthin. The analysis of the absorption spectra of canthaxanthin in the lipid phase and 1H-NMR spectra of lipids point to the exceptionally low aggregation threshold of the pigment in the membrane environment (∼1 mol%). All results demonstrate a very strong modifying effect of canthaxanthin with respect to the dynamic and structural properties of lipid membranes. 相似文献
954.
Dybala-Defratyka A Rostkowski M Paneth P 《Archives of biochemistry and biophysics》2008,474(2):274-282
The application of kinetic isotope effects and molecular modeling to characterize three enzyme-catalyzed reactions is presented; the mechanism of the chloroacid dehalogenase catalyzed reaction is approached using chlorine kinetic isotope effects and solvent kinetic isotope effects. The pre-steady-state phase of the reaction catalyzed by methylmalonyl-CoA mutase is approached by different QM/MM schemes and the results are validated by comparison with the experimental value of the deuterium kinetic isotope effect. Finally, a procedure for improving QM/MM calculations is illustrated by analysis of the trihydroxynaphthalene reductase-catalyzed reaction. 相似文献
955.
Heme proteins that have been reconstituted with certain hemins may contain substantial fractions of a minor component in which the orientation of the heme in the folded pocket differs from the major ("native") conformation by a 180 degrees rotation about the alpha-gamma meso axis. In fact, this minor component has also been shown to exist in some native proteins, including several mammalian globins. While resonance Raman spectroscopy has emerged as a powerful probe of active site structure of heme proteins, no systematic study has yet been undertaken to elucidate the specific spectral changes associated with this disorder. In the present work, combined analyses of the temporal behavior of both NMR and RR data sets have been completed to permit the extraction of a unique RR spectrum for the disoriented form, documenting rather dramatic changes associated with this rotational disorder. In addition, the use of protohemes bearing selectively deuterated peripheral methyl groups has permitted the association of the observed modes with specific fragments of the heme residing in the reversed orientation. The studies conducted here clearly illustrate the exquisite sensitivity of low frequency heme deformation modes to altered protein-heme interactions. 相似文献
956.
Influence of macromolecular crowding on protein-protein association rates--a Brownian dynamics study
The high total concentration of macromolecules, often referred to as macromolecular crowding, is one of the characteristic features of living cells. Macromolecular crowding influences interactions between many types of macromolecules, with consequent effects on, among others, the rates of reactions occurring in the cell. Simulations to study the influence of crowding on macromolecular association rate were performed using a modified Brownian dynamics protocol. The calculated values of the time-dependent self-diffusion coefficients in different crowding conditions are in a very good agreement with those obtained by other authors. Simulations of the complex formation between the monoclonal antibody HyHEL-5 and its antigen hen egg lysozyme, both represented at atomic level detail, show that the calculated association rates strongly depend on the volume excluded by crowding. The rate obtained for the highest concentration of crowding particles is greater than twofold higher than the rate for proteins without crowding. 相似文献
957.
Simple Method for Plating Escherichia coli Bacteriophages Forming Very Small Plaques or No Plaques under Standard Conditions 下载免费PDF全文
Joanna M. o Piotr Golec Grzegorz Wgrzyn Alicja Wgrzyn Marcin o 《Applied microbiology》2008,74(16):5113-5120
The use of low concentrations (optimally 2.5 to 3.5 μg/ml, depending on top agar thickness) of ampicillin in the bottom agar of the plate allows for formation of highly visible plaques of bacteriophages which otherwise form extremely small plaques or no plaques on Escherichia coli lawns. Using this method, we were able to obtain plaques of newly isolated bacteriophages, propagated after induction of prophages present in six E. coli O157:H− strains which did not form plaques when standard plating procedures were employed. 相似文献
958.
Kozakiewicz A Neumann P Banach M Komoszyński M Wojtczak A 《Acta biochimica Polonica》2008,55(1):141-150
Nucleoside triphosphate diphosphohydrolase--NTPDase1 (apyrase, EC 3.6.1.5) was modeled based on sequence homology. The single polypeptide chain of apyrase is folded into two domains. The putative catalytic site with the apyrase conserved regions (ACR 1-5) is located between these two domains. Modeling confirmed that apyrase belongs to the actin superfamily of proteins. The amino acids interacting with the nucleoside triphosphate substrate and probably involved in the catalyzed hydrolysis were identified. The proposed two-step catalytic mechanism of hydrolysis involves Thr127 and Thr55 as potential nucleophilic factors responsible for the cleavage of the Pgamma and Pbeta anhydride bonds, respectively. Their action seems to be assisted by Glu170 and Glu78 residues, respectively. The presence of two nucleophiles in the active site of apyrase explains the differences in the hydrolytic activity between apyrases and other enzymes belonging to the NTPDase family. 相似文献
959.
960.
Van Lenten BJ Wagner AC Jung CL Ruchala P Waring AJ Lehrer RI Watson AD Hama S Navab M Anantharamaiah GM Fogelman AM 《Journal of lipid research》2008,49(11):2302-2311
4F is an anti-inflammatory, apolipoprotein A-I (apoA-I)-mimetic peptide that is active in vivo at nanomolar concentrations in the presence of a large molar excess of apoA-I. Physiologic concentrations ( approximately 35 microM) of human apoA-I did not inhibit the production of LDL-induced monocyte chemotactic activity by human aortic endothelial cell cultures, but adding nanomolar concentrations of 4F in the presence of approximately 35 microM apoA-I significantly reduced this inflammatory response. We analyzed lipid binding by surface plasmon resonance. The anti-inflammatory 4F peptide bound oxidized lipids with much higher affinity than did apoA-I. Initially, we examined the binding of PAPC (1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine) and observed that its oxidized products bound 4F with an affinity that was approximately 4-6 orders of magnitude higher than that of apoA-I. This high binding affinity was confirmed in studies with defined lipids and phospholipids. 3F-2 and 3F(14) are also amphipathic alpha-helical octadecapeptides, but 3F-2 inhibits atherosclerosis in mice and 3F(14) does not. Like 4F, 3F-2 also bound oxidized phospholipids with very high affinity, whereas 3F(14) resembled apoA-I. The extraordinary ability of 4F to bind pro-inflammatory oxidized lipids probably accounts for its remarkable anti-inflammatory properties. 相似文献