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101.
102.
Adsorption of proteins onto membranes can alter the local membrane curvature. This phenomenon has been observed in biological processes such as endocytosis, tubulation, and vesiculation. However, it is not clear how the local surface properties of the membrane, such as membrane tension, change in response to protein adsorption. In this article, we show that the partial differential equations arising from classical elastic model of lipid membranes, which account for simultaneous changes in shape and membrane tension due to protein adsorption in a local region, cannot be solved for nonaxisymmetric geometries using straightforward numerical techniques; instead, a viscous-elastic formulation is necessary to fully describe the system. Therefore, we develop a viscous-elastic model for inhomogeneous membranes of the Helfrich type. Using the newly available viscous-elastic model, we find that the lipids flow to accommodate changes in membrane curvature during protein adsorption. We show that, at the end of protein adsorption process, the system sustains a residual local tension to balance the difference between the actual mean curvature and the imposed spontaneous curvature. We also show that this change in membrane tension can have a functional impact such as altered response to pulling forces in the presence of proteins. 相似文献
103.
Life satisfaction refers to a somewhat stable cognitive assessment of one’s own life. Life satisfaction is an important component of subjective well being, the scientific term for happiness. The other component is affect: the balance between the presence of positive and negative emotions in daily life. While affect has been studied using social media datasets (particularly from Twitter), life satisfaction has received little to no attention. Here, we examine trends in posts about life satisfaction from a two-year sample of Twitter data. We apply a surveillance methodology to extract expressions of both satisfaction and dissatisfaction with life. A noteworthy result is that consistent with their definitions trends in life satisfaction posts are immune to external events (political, seasonal etc.) unlike affect trends reported by previous researchers. Comparing users we find differences between satisfied and dissatisfied users in several linguistic, psychosocial and other features. For example the latter post more tweets expressing anger, anxiety, depression, sadness and on death. We also study users who change their status over time from satisfied with life to dissatisfied or vice versa. Noteworthy is that the psychosocial tweet features of users who change from satisfied to dissatisfied are quite different from those who stay satisfied over time. Overall, the observations we make are consistent with intuition and consistent with observations in the social science research. This research contributes to the study of the subjective well being of individuals through social media. 相似文献
104.
Cycloheximide is a strong inducer of the c-jun protooncogene mRNA at concentrations (≤50 ng/ml) that do not inhibit protein synthesis in human monocytes. This induction is transient lasting 30–60 min in contrast to the sustained induction obtained with concentrations that inhibit protein synthesis. The pluripotent colony stimulating factor interleukin-3 (IL-3) (10 ng/ml) is also a modest inducer of the c-jun gene in these cells; however, in combination with cycloheximide, IL-3 dramatically reduces the c-jun induction below levels induced by cycloheximide alone. This is a true inhibition and is not due to a change in temporal kinetics of induction because the suppression in the presence of IL-3 is observed at both 30 and 60 min after simultaneous addition of both IL-3 and cycloheximide. Preincubation of monocytes with 12.5 nM okadaic acid (a potent inhibitor of protein phosphatases 1 and 2A) and cycloheximide prior to addition of IL-3 restored the level of c-jun induction to that mediated by cycloheximide alone. This concentration of okadaic acid inhibited almost 70% of the phosphorylase phosphatase activity in monocyte lysates. These observations suggest that activation of protein serine/threonine phosphatase(s) underlies the ability of IL-3 to inhibit cycloheximide induction of c-jun in monocytes. © 1993 Wiley-Liss, Inc. 相似文献
105.
Background
Accuracy of document retrieval from MEDLINE for gene queries is crucially important for many applications in bioinformatics. We explore five information retrieval-based methods to rank documents retrieved by PubMed gene queries for the human genome. The aim is to rank relevant documents higher in the retrieved list. We address the special challenges faced due to ambiguity in gene nomenclature: gene terms that refer to multiple genes, gene terms that are also English words, and gene terms that have other biological meanings. 相似文献106.
R. Padmini V. Uma Maheshwari P. Saravanan Keun Woo Lee M. Razia Mona S. Alwahibi B. Ravindran Mohamed Soliman Elshikh Young Ock Kim Hyungsuk Kim Hak-Jae Kim 《Saudi Journal of Biological Sciences》2020,27(12):3274-3289
Garlic (Allium sativum L.), is a predominant spice, which is used as an herbal medicine and flavoring agent, since ancient times. It has a rich source of various secondary metabolites such as flavonoids, terpenoids and alkaloids, which have various pharmacological properties. Garlic is used in the treatment of various ailments such as cancer, diabetes and cardiovascular diseases. The present study aims to explore the plausible mechanisms of the selected phytocompounds as potential inhibitors against the known drug targets of non-small-cell lung cancer (NSCLC). The phytocompounds of garlic were identified by gas chromatography-mass spectrometry (GC–MS) technique. Subsequently, the identified phytocompounds were subjected to molecular docking to predict the binding with the drug targets, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) and group IIa secretory phospholipase A2 (sPLA2-IIA). Molecular dynamics is used to predict the stability of the identified phytocompounds against NSCLC drug targets by refining the intermolecular interactions formed between them. Among the 12 phytocompounds of garlic, three compounds[1,4-dimethyl-7-(1-methylethyl)-2-azulenyl]phenylmethanone, 2,4-bis(1-phenylethyl)-phenol and 4,5–2 h-oxazole-5-one,4-[3,5-di-t-butyl-4-methoxyphenyl] methylene-2-phenyl were identified as potential inhibitors, which might be suitable for targeting the different clinical forms of EGFR and dual inhibition of the studied drug targets to combat NSCLC. The result of this study suggest that these identified phytocompounds from garlic would serve as promising leads for the development of lead molecules to design new multi-targeting drugs to address the different clinical forms of NSCLC. 相似文献
107.
P. Padmini S. J. Khedoe Geerte Hoeke Sander Kooijman Wieneke Dijk Jeroen T. Buijs Sander Kersten Louis M. Havekes Pieter S. Hiemstra Jimmy F. P. Berbée Mari?tte R. Boon Patrick C. N. Rensen 《Journal of lipid research》2015,56(1):51-59
Brown adipose tissue (BAT) produces heat by burning TGs that are stored within intracellular lipid droplets and need to be replenished by the uptake of TG-derived FA from plasma. It is currently unclear whether BAT takes up FA via uptake of TG-rich lipoproteins (TRLs), after lipolysis-mediated liberation of FA, or via a combination of both. Therefore, we generated glycerol tri[3H]oleate and [14C]cholesteryl oleate double-labeled TRL-mimicking particles with an average diameter of 45, 80, and 150 nm (representing small VLDL to chylomicrons) and injected these intravenously into male C57Bl/6J mice. At room temperature (21°C), the uptake of 3H-activity by BAT, expressed per gram of tissue, was much higher than the uptake of 14C-activity, irrespective of particle size, indicating lipolysis-mediated uptake of TG-derived FA rather than whole particle uptake. Cold exposure (7°C) increased the uptake of FA derived from the differently sized particles by BAT, while retaining the selectivity for uptake of FA over cholesteryl ester (CE). At thermoneutrality (28°C), total FA uptake by BAT was attenuated, but the specificity of uptake of FA over CE was again largely retained. Altogether, we conclude that, in our model, BAT takes up plasma TG preferentially by means of lipolysis-mediated uptake of FA. 相似文献
108.
109.
Krill plays a significant role in the Barents Sea ecosystem, providing energy transport between different trophic levels.
The current paper presents the results of a long-term study (1980–2009) based on pelagic trawl catches from August to September.
Our investigations show that the krill species were distributed widely in the Barents Sea and that the largest krill concentrations
were restricted to the west-central and eastern parts of the Barents Sea. The current paper presents the relative biomass
indices, and the estimates must be interpreted as minimum biomass. The mean annual krill biomass was estimated to be 22 million
tonnes in wet weight, with the highest values being as much as 48 million tonnes. Capelin is the largest pelagic stock, and
in some years, their biomass can amount to 4–7 million tonnes, which can impose high predation pressure on krill. When their
biomass is high, capelin may consume close to 26 million tonnes annually. The predation from pelagic (herring and blue whiting)
and bottom (cod and haddock) fish species was much lower, being 9 and 1 million tonnes, respectively. A negative relationship
between krill biomass and capelin stock size above 74°N was observed during the study period. However, during the last decade,
the krill biomass has increased despite heavy predation from capelin in some years. A positive significant linear relationship
between the mean annual Kola temperature and the krill biomass seems to indicate that the recent warming conditions have favourable
impacts on the krill populations in the Barents Sea. 相似文献
110.
Padmini Ramaswamy 《Inorganica chimica acta》2011,372(1):136-144
Five new open-framework compounds of gallium have been synthesized by hydrothermal methods and their structures determined by single crystal X-ray diffraction studies. The compounds, [C8N4H26][Ga6F4(PO4)6], I, [C5N3H11][Ga3F2(PO4)3]·H2O, II, [C6N3H19][Ga4(C2O4)(PO4)4(H2PO4)]·2H2O, III, [Ga2F3(HPO4)(PO4)]·2H3O, IV, and [C3N2H5]2[Ga4(H2O)3(HPO3)7], V, possess three-dimensional structures. All the compounds are formed by the connectivity between the Ga polyhedra and phosphite/phosphate units. The observation of SBU-6 (I and II) and spiro-5 (IV) secondary building units (SBUs) are noteworthy. The flexibility of the formation of gallium phosphate frameworks has been established by the isolation of two related structures (I and II) from the same SBU units but different organic amines. Some of the present structures have close resemblance to the gallium phosphate phases known earlier. The compounds have been characterized by CHN analysis, powder XRD, IR, and TGA. 相似文献