scholarly journals Structural characterization of fibrous synthetic hydrogels using fluorescence microscopy

Soft Matter ◽  
2020 ◽  
Vol 16 (17) ◽  
pp. 4210-4219 ◽  
Author(s):  
Johannes Vandaele ◽  
Boris Louis ◽  
Kaizheng Liu ◽  
Rafael Camacho ◽  
Paul H. J. Kouwer ◽  
...  

The structural features of the matrix surrounding the cells play a crucial role in regulating their behavior.

2007 ◽  
Vol 546-549 ◽  
pp. 1111-1116 ◽  
Author(s):  
Ming An Chen ◽  
Xuan Xie ◽  
Guo Fu Xu ◽  
Hui Zhong Li ◽  
Xin Ming Zhang

2024-T6 Al alloy sheet s were modified by bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) silane film to improve the corrosion resistance. Fourier-Transform Reflection Absorption (FTIR-RA) spectroscopy was used for structural characterization of BTESPT silane film formed on surface of the sheet. Potentiodynamic polarization and immersion test in 3.5% NaCl solution were used for evaluating the corrosion performances of the silane film. The results showed that the film formed after curing at 120 °C for 40 min was cross-linked through Si-O-Si and that it was covered on the entire surface of the sheet. The content of elements S and Si on the Al2CuMg particles is a little higher that of on the matrix. The strong peak at 1032 cm-1 indicated that the film was linked to the sheet by Si-O-Al. Compared to the untreated case, the corrosion current density of the sheet treated with the silane film was reduced by close to 2 orders. Treatment of BTESPT silane can provide about 670 h protection of corrosion for the sheet in 3.5% NaCl water solution.


2015 ◽  
Vol 44 (29) ◽  
pp. 13378-13383 ◽  
Author(s):  
Gail M. Sequeira ◽  
Wayne Y. Tan ◽  
Evan G. Moore

The synthesis and structural characterization of a series of lanthanide complexes formed from YbX3 salts (X = NO3− or CF3SO3−) and the isomeric 4,4′-bipyridine-N,N′-dioxide (4,4′-bpdo) or 3,3′-bipyridine-N,N′-dioxide (3,3′-bpdo) ligands has been undertaken by X-ray crystallography.


Author(s):  
Pham Thu Thuy ◽  
Pham Chien Thang ◽  
Nguyen Viet Ha ◽  
Trieu Thi Nguyet

The curcumin derivative 4’,4’’-dibenzoylcurcumin (HL) was synthesized by the reaction between curcumin and benzoyl chloride in the presence of pyridine as a supporting base. The composition and structure of HL were characterized by spectroscopic methods such as IR, 1H and 13C NMR spectroscopy. Reactions of HL and transition metal ions, such as Fe3+ and Cu2+, in mixtures of CH3OH and CH2Cl2 gave rise to the corresponding complexes, compositions and structural features of which were studied by thermal analysis and IR spectroscopy. The results strongly suggested the obtained complexes with the compositions of [FeL3] and [CuL2]. In such compounds, metal ions coordinates with the deprotonated ligands L– through the donor sets (O,O) of the keto-enol moieties. Keywords: Curcumin, 4’,4’’-dibenzoylcurcumin, β-diketone, Fe(III) complexes, Cu(II) complexes. References [1] A. Goel, A.B. Kannumakkara, B.B. Aggarwal, Curcumin as “Curecumin”: From Kitchen to Clinic, Biochem. Pharmacol. 75 (2008) 787-809. https://doi.org/10.1016/j.bcp.2007.08.016.[2] T. Esatbeyoglu, P. Huebbe, I.M.A. Ernst, D. Chin, A.E. Wagner, G. Rimbach, Curcumin - From Molecule to Biological Function, Angew. Chem. Int. Ed. 51 (2012) 5308-5332. https://doi.org/ 10.1002/anie.201107724.[3] K. Priyadarsini, The Chemistry of Curcumin: From Extraction to Therapeutic Agent, Molecules 19 (2014) 20091-20112. https://doi.org/10.3390/ molecules191220091.[4] S. Wanninger, V. Lorenz, A. Subhan, F.T. Edelmann, Metal complexes of curcumin – synthetic strategies, structures and medicinal applications, Chem. Soc. Rev. 44 (2015) 4986-5002. https://doi.org/10.1039/C5CS00088B.[5] J. Wang, D. Wei, B. Jiang, T. Liu, J. Ni, S. Zhou, Two copper(II) complexes of curcumin derivatives: synthesis, crystal structure and in vitro antitumor activity, Transition Met. Chem. 39 (2014) 553-558. https://doi.org/10.1007/s11243-014-9831-z.[6] R. Pettinari, F. Marchetti, C. Pettinari, F. Condello, A. Petrini, R. Scopelliti, T. Riedel, P.J. Dyson, Organometallic rhodium(III) and iridium(III) cyclopentadienyl complexes with curcumin and bisdemethoxycurcumin co-ligands, Dalton Transactions 44 (2015) 20523-20531. https://doi.org/10.1039/C5DT03037D.[7] P.T. Thùy, P.C. Thắng, N.H. Huy, N.V. Hà, T.T. Nguyệt, Synthesis, structural characterization of 4,4’-diacetylcurcumin and its complexes with Fe(III), Co(II) (in Vietnamese), Vietnam Journal of Chemistry 55 (2017) 33-37. [8] P.C. Thắng, P.T. Thùy, T.T.K. Ngân, L.C. Định, Đ.T. Đạt, T.T. Nguyệt, Synthesis, structural characterization of 4’,4’’-dimethoxy-4-methylcurcumin and evaluation of its complexation with Co2+ and Cu2+ (in Vietnamese), Vietnam Journal of Chemistry 56 (2018) 113-117. [9] P.T. Thùy, P.C. Thắng, V.T.B. Ngoc, T.T. Nguyệt, Synthesis and structural characterization of a heteroleptic Pd(II) complex with 4,4’-diacetylcurcumin (in Vietnamese), Vietnam Journal of Chemistry 56 (2018) 119-123. [10] K. Singletary, C. MacDonald, M. Iovinelli, C. Fisher, M. Wallig, Effect of the beta-diketones diferuloylmethane (curcumin) and dibenzoylmethane on rat mammary DNA adducts and tumors induced by 7,12-dimethylbenz[a] anthracene, Carcinogenesis 19 (1998) 1039-1043. https://doi.org/10.1093/carcin/ 19.6.1039.[11] F. Payton, P. Sandusky, W.L. Alworth, NMR Study of the Solution Structure of Curcumin, J. Nat. Prod. 70 (2007) 143-146. https://doi.org/10. 1021/np060263s.  


2019 ◽  
Author(s):  
Ho Yee Joyce Fung ◽  
Kristen McKibben ◽  
Jennifer Ramirez ◽  
Kushol Gupta ◽  
Elizabeth Rhoades

SummaryTau is a neuronal microtubule (MT) associated protein of significant interest due to its association with several neurodegenerative disorders. Tau’s intrinsic disorder and the dynamic nature of its interactions with tubulin and MTs make its structural characterization challenging. Here we use an environmentally sensitive fluorophore as a site-specific probe of tau bound to soluble tubulin. Comparison of our results with recently published tau:MT cryo-EM model reveals structural similarities between tubulin- and MT-bound tau. Analysis of residues across the repeat regions reveal a hierarchy in tubulin occupancy, which may be relevant to tau’s ability to differentiate between tubulin and MTs. As binding to soluble tubulin is a critical first step in MT polymerization, our characterization of the structural features of tau in dynamic, fuzzy tau:tubulin assemblies advances our understanding of how tau functions in the cell and how function may be disrupted in disease.


2011 ◽  
Vol 83 (12) ◽  
pp. 4909-4915 ◽  
Author(s):  
Emily C. Heider ◽  
Moussa Barhoum ◽  
Kyle Edwards ◽  
Karl-Heinz Gericke ◽  
Joel M. Harris

2020 ◽  
pp. mcp.R120.002267
Author(s):  
Lauren E. Pepi ◽  
Patience Sanderson ◽  
Morgan Stickney ◽  
I. Jonathan Amster

This review covers recent developments in glycosaminoglycan (GAG) analysis via mass spectrometry (MS). GAGs participate in a variety of biological functions, including cellular communication, wound healing, and anticoagulation, and are important targets for structural characterization. GAGs exhibit a diverse range of structural features due to the variety of O- and N-sulfation modifications and uronic acid C-5 epimerization that can occur, making their analysis a challenging target. Mass spectrometry approaches to the structure assignment of GAGs have been widely investigated, and new methodologies remain the subject of development. Advances in sample preparation, tandem MS techniques (MS/MS), on-line separations and automated analysis software have advanced the field of GAG analysis. These recent developments have led to remarkable improvements in the precision and time efficiency for the structural characterization of GAGs.


2005 ◽  
Vol 33 (1) ◽  
pp. 137-140 ◽  
Author(s):  
B. Burlat ◽  
J.D. Gwyer ◽  
S. Poock ◽  
T. Clarke ◽  
J.A. Cole ◽  
...  

The recent structural characterization of the NrfA from Escherichia coli provides a framework to rationalize the spectroscopic and functional properties of this enzyme. Analyses by EPR and magnetic CD spectroscopies have been complemented by protein-film voltammetry and these are discussed in relation to the essential structural features of the enzyme.


2020 ◽  
Author(s):  
Ilias Patmanidis ◽  
Alex H. de Vries ◽  
Tsjerk A. Wassenaar ◽  
Wenjun Wang ◽  
Giuseppe Portale ◽  
...  

Self-assembled nanostructures arise when building blocks spontaneously organize into ordered aggregates that exhibit different properties compared to the disorganized monomers. Here, we study an amphiphilic cyanine dye (C8S3) that is known to self-assemble into doublewalled, hollow, nanotubes with interesting optical properties. The molecular packing of the dyes inside the nanotubes, however, remains elusive. To reveal the structural features of the C8S3 nanotubes, we performed atomistic Molecular Dynamics simulations of preformed bilayers and nanotubes. We find that different packing arrangements lead to stable structures, in which the tails of the C8S3 molecules are interdigitated. Our results are verified by SAXS experiments. Together our data provide a detailed structural characterization of the C8S3 nanotubes. Furthermore, our approach was able to resolve the ambiguity inherent from cryo-TEM measurements in calculating the wall thickness of similar systems. The insights obtained are expected to be generally useful for understanding and designing other supramolecular assemblies.<br>


2015 ◽  
Vol 35 (1) ◽  
Author(s):  
Larissa M. Laine ◽  
Marco Biddau ◽  
Olwyn Byron ◽  
Sylke Müller

The malaria parasite dihydrolipoamide dehydrogenase is active as a dimer and has specific structural features which could be exploitable for drug discovery. The enzyme is not essential for blood stage development but loss of function affects redox homoeostasis and cell cycle.


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