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( Nelly Christova ),( Sieg Mund Lang ),( Victor Wray ),( Kaloyan Kaloyanov ),( Spiro Konstantinov ),( Ivanka Stoineva ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.4
The objective of this study was to isolate and identify the chemical structure of a biosurfactant produced by Nocardia farcinica strain BN26 isolated from soil, and evaluate its in vitro antitumor activity on a panel of human cancer cell lines. Strain BN26 was found to produce glycolipid biosurfactant on n-hexadecane as the sole carbon source. The biosurfactant was purified using medium-pressure liquid chromatography and characterized as trehalose lipid tetraester (THL) by nuclear magnetic resonance spectroscopy and mass spectrometry. Subsequently, the cytotoxic effects of THL on cancer cell lines BV-173, KE-37 (SKW-3), HL-60, HL-60/DOX, and JMSU-1 were evaluated by MTT assay. It was shown that THL exerted concentration-dependent antiproliferative activity against the human tumor cell lines and mediated cell death by the induction of partial oligonucleosomal DNA fragmentation. These findings suggest that THL could be of potential to apply in biomedicine as a therapeutic agent.
Warren Wiechmann,Robert Edwards,Cheyenne Low,Alisa Wray,Megan Boysen-Osborn,Shannon Toohey 한국보건의료인국가시험원 2022 보건의료교육평가 Vol.19 No.-
Purpose: Technological advances are changing how students approach learning. The traditional note-taking methods of longhandwriting have been supplemented and replaced by tablets, smartphones, and laptop note-taking. It has been theorized that writing notesby hand requires more complex cognitive processes and may lead to better retention. However, few studies have investigated the use oftablet-based note-taking, which allows the incorporation of typing, drawing, highlights, and media. We therefore sought to confirm thehypothesis that tablet-based note-taking would lead to equivalent or better recall as compared to written note-taking. Methods: We allocated 68 students into longhand, laptop, or tablet note-taking groups, and they watched and took notes on a presentation on which they were assessed for factual and conceptual recall. A second short distractor video was shown, followed by a 30-minuteassessment at the University of California, Irvine campus, over a single day period in August 2018. Notes were analyzed for content,supplemental drawings, and other media sources. Results: No significant difference was found in the factual or conceptual recall scores for tablet, laptop, and handwritten note-taking(P=0.61). The median word count was 131.5 for tablets, 121.0 for handwriting, and 297.0 for laptops (P=0.01). The tablet group hadthe highest presence of drawing, highlighting, and other media/tools. Conclusion: In light of conflicting research regarding the best note-taking method, our study showed that longhand note-taking is notsuperior to tablet or laptop note-taking. This suggests students should be encouraged to pick the note-taking method that appeals mostto them. In the future, traditional note-taking may be replaced or supplemented with digital technologies that provide similar efficacywith more convenience
Manganese-cobalt hexacyanoferrate cathodes for sodium-ion batteries
Pasta, Mauro,Wang, Richard Y.,Ruffo, Riccardo,Qiao, Ruimin,Lee, Hyun-Wook,Shyam, Badri,Guo, Minghua,Wang, Yayu,Wray, L. Andrew,Yang, Wanli,Toney, Michael F.,Cui, Yi The Royal Society of Chemistry 2016 Journal of materials chemistry. A, Materials for e Vol.4 No.11
<P>Prussian Blue analogues (PBAs) have shown promise as electrode materials for grid-scale batteries because of their high cycle life and rapid kinetics in aqueous-based electrolytes. However, these materials suffer from relatively low specific capacity, which may limit their practical applications. Here, we investigate strategies to improve the specific capacity of these materials while maintaining their cycling stability and elucidate mechanisms that enhance their electrochemical properties. In particular, we have studied the electrochemical and structural properties of manganese hexacyanoferrate (MnHCFe) and cobalt hexacyanoferrate (CoHCFe) in an aqueous, sodium-ion electrolyte. We also studied manganese-cobalt hexacyanoferrate (Mn-CoHCFe) solid solutions with different Mn/Co ratios that combine properties of both MnHCFe and CoHCFe. The materials have the characteristic open-framework crystal structure of PBAs, and their specific capacities can be significantly improved by electrochemically cycling (oxidizing and reducing) both the carbon-coordinated Fe and the nitrogen-coordinated Co or Mn ions.<I>In situ</I>synchrotron X-ray diffraction studies and<I>ex situ</I>soft X-ray absorption spectroscopy combined with an in-depth electrochemical characterization provide insight into the different electrochemical properties associated with the Fe, Co, and Mn redox couples. We show that cycling the C-coordinated Fe preserves the crystal structure and enables the outstanding kinetics and cycle life previously displayed by PBAs in aqueous electrolytes. On the other hand, the N-coordinated Co and Mn ions exhibit a slower kinetic regime due to structural distortions resulting from the weak N-coordinated crystal field, but they still contribute significantly towards increasing the specific capacity of the materials. These results provide the understanding needed to drive future development of PBAs for grid-scale applications that require extremely high cycle life and kinetics.</P>
Rö,nsberg, David,Debbab, Abdessamad,Má,ndi, Attila,Vasylyeva, Vera,Bö,hler, Philip,Stork, Bjö,rn,Engelke, Laura,Hamacher, Alexandra,Sawadogo, Richard,Diederich, Marc,Wray, Vict American Chemical Society 2013 Journal of organic chemistry Vol.78 No.24
<P>Four tetrahydroxanthone dimers (<B>1</B>–<B>4</B>) and four biogenetically related monomers (<B>5</B>–<B>8</B>), including the new derivatives <B>4</B>–<B>6</B>, were isolated from the endophyte Phomopsis longicolla. The absolute configurations of <B>2</B>–<B>4</B> were established for the first time by TDDFT electronic circular dichroism calculations, and that of phomoxanthone A (<B>1</B>) was revised by X-ray crystallography. Phomoxanthone A (<B>1</B>) showed the strongest pro-apoptotic activity when tested against a panel of human cancer cell lines, including cisplatin-resistant cells, whereas it was up to 100-fold less active against healthy blood cells. It was also the most potent activator of murine T lymphocytes, NK cells, and macrophages, suggesting an activation of the immune system in parallel to its pro-apoptotic activity. This dual effect in combating cancer cells could help in fighting resistance during chemotherapy. Preliminary structure–activity studies of isolated compounds and derivatives obtained by semisynthesis (<B>9a</B>–<B>11</B>) hinted at the location of the biaryl axis and the presence of acetyl groups as important structural elements for the biological activity of the studied tetrahydroxanthones.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2013/joceah.2013.78.issue-24/jo402066b/production/images/medium/jo-2013-02066b_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jo402066b'>ACS Electronic Supporting Info</A></P>