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51.
Phospholipids (PLs) are a class of lipids with many proven biological functions. They are commonly used in lipid replacement therapy to enrich cell membranes damaged in chronic neurodegenerative diseases, cancer, or aging processes. Due to their amphipathic nature, PLs have been widely used in food, cosmetic, and pharmaceutical products as natural emulsifiers and components of liposomes. In Yarrowia lipolytica, PLs are synthesized through a similar pathway like in higher eukaryotes. However, PL biosynthesis in this yeast is still poorly understood. The key intermediate in this pathway is phosphatidic acid, which in Y. lipolytica is mostly directed to the production of triacylglycerols and, in a lower amount, to PL. This study aimed to deliver a strain with improved PL production, with a particular emphasis on increased biosynthesis of phosphatidylcholine (PC). Several genetic modifications were performed: overexpression of genes from PL biosynthesis pathways as well as the deletion of genes responsible for PL degradation. The best performing strain (overexpressing CDP-diacylglycerol synthase (CDS) and phospholipid methyltransferase (OPI3)) reached 360% of PL improvement compared to the wild-type strain in glucose-based medium. With the substitution of glucose by glycerol, a preferred carbon source by Y. lipolytica, an almost 280% improvement of PL was obtained by transformant overexpressing CDS, OPI3, diacylglycerol kinase (DGK1), and glycerol kinase (GUT1) in comparison to the wild-type strain. To further increase the amount of PL, the optimization of culture conditions, followed by the upscaling to a 2 L bioreactor, were performed. Crude glycerol, being a cheap and renewable substrate, was used to reduce the costs of PL production. In this process 653.7 mg/L of PL, including 352.6 mg/L of PC, was obtained. This study proved that Y. lipolytica is an excellent potential producer of phospholipids, especially from waste substrates.  相似文献   
52.
Inflammatory bowel disease (IBD) is one of the leading gut chronic inflammation disorders, especially prevalent in Western countries. Recent research suggests that mitochondria play a crucial role in IBD development and progression to the more severe disease—colorectal cancer (CRC). In this review, we focus on the role of mitochondrial mutations and dysfunctions in IBD and CRC. In addition, main mitochondria-related molecular pathways involved in IBD to CRC transition are discussed. Additionally, recent publications dedicated to mitochondria-targeted therapeutic approaches to cure IBD and prevent CRC progression are discussed.  相似文献   
53.
We used nuclear hyperfine spectroscopies and a 57Fe probe layer approach to study the depth-dependent magnetic properties of ultrathin Fe films on NiO(0 0 1), a system exhibiting exchange bias. Conversion electron Mössbauer spectroscopy and nuclear resonance scattering of synchrotron radiation were employed. The samples were two Fe films with a thickness (8–10 ML) slightly above the critical thickness for the onset of ferromagnetism at room temperature, in which a 2 ML-thick probe layer, enriched in the 57Fe Mössbauer isotope, was embedded at different depths from the Fe/NiO interface. Both techniques indicate that inside the film Fe has a metallic character, while at the interface with NiO different Fe phases are present. The main conclusion is that already a few monolayers from the interface with NiO the magnetic properties of Fe are bulk-like.  相似文献   
54.
The aim of the present article was an attempt to compare the influence of the presence of a diesel particulate filter (DPF) on the content of contaminants (Fe, Cr, Ni, Pb) and the level of changes of physical and chemical parameters (such as kinematic viscosity, TBN, TAN) in engine oils during their service life. The article presents changes occurring in engine oils at various stages of use. Medium infrared Eralitics ERASPEC OIL FT-IR spectrometer and XOS HDMaxine (powered by High Definition X-ray Fluorescence) were used. Based on the conducted experiment, statistically significant differences in diesel fuel content were noticed.  相似文献   
55.
The aim of this study was to evaluate the antioxidant properties of apple slices stored in edible starch films enriched with white and green tea extracts. All results were compared to that obtained for apple slices stored in polyethylene films. The use of starch films, as carrier of antioxidants, prolonged the storage life and improved quality of fresh-cut apples at the end of storage; however, deteriorated their lightness and increased their browning. Apple slices coated in starch films enriched with tea extracts exhibited higher antioxidant properties than those without these additives, as well as those in polyethylene films.  相似文献   
56.
Two non-conducting chemicals, aniline and silver nitrate, dissolved in formic acid solutions, yielded a composite of two conducting products, polyaniline and silver. As the concentration of formic acid increased, an alternative reaction, the reduction of silver nitrate with formic acid to silver became dominant, and the content of silver in the composites increased. The formation of polyaniline was confirmed by UV–visible, FTIR, and Raman spectroscopies. The typical conductivity of composites was 43 S cm?1 at 84 wt.% of silver. Silver nanowires coated with polyaniline nanobrushes are produced at low concentrations of formic acid, the granular silver particles covered with polyaniline dominate at high acid concentrations.  相似文献   
57.
CXCL16 is a chemotactic cytokine belonging to the α-chemokine subfamily. It plays a significant role in the progression of cancer, as well as the course of atherosclerosis, renal fibrosis, and non-alcoholic fatty liver disease (NAFLD). Since there has been no review paper discussing the importance of this chemokine in various diseases, we have collected all available knowledge about CXCL16 in this review. In the first part of the paper, we discuss background information about CXCL16 and its receptor, CXCR6. Next, we focus on the importance of CXCL16 in a variety of diseases, with an emphasis on cancer. We discuss the role of CXCL16 in tumor cell proliferation, migration, invasion, and metastasis. Next, we describe the role of CXCL16 in the tumor microenvironment, including involvement in angiogenesis, and its significance in tumor-associated cells (cancer associated fibroblasts (CAF), microglia, tumor-associated macrophages (TAM), tumor-associated neutrophils (TAN), mesenchymal stem cells (MSC), myeloid suppressor cells (MDSC), and regulatory T cells (Treg)). Finally, we focus on the antitumor properties of CXCL16, which are mainly caused by natural killer T (NKT) cells. At the end of the article, we summarize the importance of CXCL16 in cancer therapy.  相似文献   
58.
To identify the physiological factors that limit the growth of Escherichia coli K-12 strains synthesizing minimal lipopolysaccharide (LPS), we describe the first construction of strains devoid of the entire waa locus and concomitantly lacking all three acyltransferases (LpxL/LpxM/LpxP), synthesizing minimal lipid IVA derivatives with a restricted ability to grow at around 21 °C. Suppressors restoring growth up to 37 °C of Δ(gmhD-waaA) identified two independent single-amino-acid substitutions—P50S and R310S—in the LPS flippase MsbA. Interestingly, the cardiolipin synthase-encoding gene clsA was found to be essential for the growth of ΔlpxLMP, ΔlpxL, ΔwaaA, and Δ(gmhD-waaA) bacteria, with a conditional lethal phenotype of Δ(clsA lpxM), which could be overcome by suppressor mutations in MsbA. Suppressor mutations basS A20D or basR G53V, causing a constitutive incorporation of phosphoethanolamine (P-EtN) in the lipid A, could abolish the Ca++ sensitivity of Δ(waaC eptB), thereby compensating for P-EtN absence on the second Kdo. A single-amino-acid OppA S273G substitution is shown to overcome the synthetic lethality of Δ(waaC surA) bacteria, consistent with the chaperone-like function of the OppA oligopeptide-binding protein. Furthermore, overexpression of GcvB sRNA was found to repress the accumulation of LpxC and suppress the lethality of LapAB absence. Thus, this study identifies new and limiting factors in regulating LPS biosynthesis.  相似文献   
59.
Garcinol extracted from Garcinia indica fruit peel and leaves is a polyisoprenylated benzophenone. In traditional medicine it was used for its antioxidant and anti-inflammatory properties. Several studies have shown anti-cancer properties of garcinol in cancer cell lines and experimental animal models. Garcinol action in cancer cells is based on its antioxidant and anti-inflammatory properties, but also on its potency to inhibit histone acetyltransferases (HATs). Recent studies indicate that garcinol may also deregulate expression of miRNAs involved in tumour development and progression. This paper focuses on the latest research concerning garcinol as a HAT inhibitor and miRNA deregulator in the development and progression of various cancers. Garcinol may be considered as a candidate for next generation epigenetic drugs, but further studies are needed to establish the precise toxicity, dosages, routes of administration, and safety for patients.  相似文献   
60.
In this study, silver nanoparticles (AgNPs) were biosynthesised by using acidophilic actinobacterial SH11 strain isolated from pine forest soil. Isolate SH11 was identified based on 16S rRNA gene sequence to Streptomyces kasugaensis M338‐M1T and S. celluloflavus NRRL B‐2493T (99.8% similarity, both). Biosynthesised AgNPs were analysed by UV–visible spectroscopy, which revealed specific peak at λ  = 420 nm. Transmission electron microscopy analyses showed polydispersed, spherical nanoparticles with a mean size of 13.2 nm, while Fourier transform infrared spectroscopy confirmed the presence of proteins as the capping agents over the surface of AgNPs. The zeta potential was found to be −16.6 mV, which indicated stability of AgNPs. The antibacterial activity of AgNPs from SH11 strain against gram‐positive (Staphylococcus aureus and Bacillus subtilis) and gram‐negative (Escherichia coli) bacteria was estimated using disc diffusion, minimum inhibitory concentration and live/dead analyses. The AgNPs showed the maximum antimicrobial activity against E. coli, followed by B. subtilis and S. aureus. Further, the synergistic effect of AgNPs in combination with commercial antibiotics (kanamycin, ampicillin, tetracycline) was also evaluated against bacterial isolates. The antimicrobial efficacy of antibiotics was found to be enhanced in the presence of AgNPs.Inspec keywords: antibacterial activity, silver, nanoparticles, electrokinetic effects, Fourier transform infrared spectra, microorganisms, nanofabricationOther keywords: actinobacterial mediated synthesis, silver nanoparticles, pathogenic bacteria, biosynthesis, acidophilic actinobacterial SH11 strain, pine forest soil, 16S rRNA gene sequence, Streptomyces kasugaensis M338‐M1T, S. celluloflavus NRRL B‐2493T, UV–visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, zeta potential, gram positive bacteria, Staphylococcus aureus, Bacillus subtilis, gram negative bacteria, Escherichia coli, disc diffusion, wavelength 420 nm, Ag  相似文献   
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