The Role of Surfactant Headgroup, Chain Length, and Cavitation Microstreaming on the Growth of Bubbles by Rectified Diffusion

2011 ◽  
Vol 115 (49) ◽  
pp. 24310-24316 ◽  
Author(s):  
Thomas Leong ◽  
James Collis ◽  
Richard Manasseh ◽  
Andrew Ooi ◽  
Anthony Novell ◽  
...  
2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.


2020 ◽  
Vol 22 (1) ◽  
pp. 152
Author(s):  
Dorota Dabrowska ◽  
Justyna Mozejko-Ciesielska ◽  
Tomasz Pokój ◽  
Slawomir Ciesielski

Pseudomonas putida’s versatility and metabolic flexibility make it an ideal biotechnological platform for producing valuable chemicals, such as medium-chain-length polyhydroxyalkanoates (mcl-PHAs), which are considered the next generation bioplastics. This bacterium responds to environmental stimuli by rearranging its metabolism to improve its fitness and increase its chances of survival in harsh environments. Mcl-PHAs play an important role in central metabolism, serving as a reservoir of carbon and energy. Due to the complexity of mcl-PHAs’ metabolism, the manner in which P. putida changes its transcriptome to favor mcl-PHA synthesis in response to environmental stimuli remains unclear. Therefore, our objective was to investigate how the P. putida KT2440 wild type and mutants adjust their transcriptomes to synthesize mcl-PHAs in response to nitrogen limitation when supplied with sodium gluconate as an external carbon source. We found that, under nitrogen limitation, mcl-PHA accumulation is significantly lower in the mutant deficient in the stringent response than in the wild type or the rpoN mutant. Transcriptome analysis revealed that, under N-limiting conditions, 24 genes were downregulated and 21 were upregulated that were common to all three strains. Additionally, potential regulators of these genes were identified: the global anaerobic regulator (Anr, consisting of FnrA, Fnrb, and FnrC), NorR, NasT, the sigma54-dependent transcriptional regulator, and the dual component NtrB/NtrC regulator all appear to play important roles in transcriptome rearrangement under N-limiting conditions. The role of these regulators in mcl-PHA synthesis is discussed.


Langmuir ◽  
2003 ◽  
Vol 19 (26) ◽  
pp. 10808-10815 ◽  
Author(s):  
Vincent Dupres ◽  
Sophie Cantin ◽  
Fewzi Benhabib ◽  
Françoise Perrot ◽  
Philippe Fontaine ◽  
...  
Keyword(s):  

2010 ◽  
Vol 117 (4) ◽  
pp. 1888-1896 ◽  
Author(s):  
E. Renard ◽  
L. Timbart ◽  
G. Vergnol ◽  
V. Langlois

2000 ◽  
Vol 526 (2) ◽  
pp. 425-434 ◽  
Author(s):  
P. J. Coleman ◽  
D. Scott ◽  
R. M. Mason ◽  
J. R. Levick

2005 ◽  
Vol 04 (05n06) ◽  
pp. 935-944 ◽  
Author(s):  
JOBIN CYRIAC ◽  
V. R. RAJEEV KUMAR ◽  
T. PRADEEP

Alkanethiol protected gold clusters of 29 kDa were prepared and separated by column chromatography. Laser desorption mass spectra of these clusters have been investigated. In the gas phase, monolayer–monolayer interaction leads to clustering of the protected clusters. Role of different matrices and effect of alkanethiol chain length on this process have been investigated.


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