Rojrit Rojanathanes

Electronic absorption spectroscopy probed side-chain movement in chromic transitions of polydiacetylene vesicles.

Thermochromism, solvatochromism, and alkalinochromism of a poly-10,12-pentacosadiynoic acid (poly(PCDA)) vesicle solution are studied by electronic absorption spectroscopy. The spectroscopic profiles reveal different sequences of side-chain movement during the chromic transitions. The gradual hypsochromic shift and reversibility of the purple solution at low temperature in the thermochromic transition indicates that the transition starts with reversible conformational alteration of methylene side chains leading to metastable purple vesicles. Further heating to 80 degrees C or higher eventually causes the hydrogen bonds at the carboxylic head groups to break and turns the vesicle solution to red. The irreversibility of the red vesicles indicates that it is the most thermodynamically stable form. In the ethanolochromism and alkalinochromism, the processes are however induced at the vesicle-media interface, directly bringing about the hydrogen bond breaking. The purple solutions observed in the ethanolochromism and alkalinochromism cannot reverse back to the blue one. The absorption spectra clearly demonstrate that they are mixtures of the blue and red vesicles.

Effect of Gold Nanoparticle on Renal Cell: An Implication for Exposure Risk

Objective. The objective of this study was to evaluate the effect of gold nanoparticles on renal cell. Intervention. This study was performed as an experimental study. A mixture of gold nanoparticle solution and renal cell sediment was prepared and further analyzed. Results. This work revealed that after mixing the renal cell sediment with gold nanoparticle solution, gold nanoparticles can be seen within the renal cells. Conclusions. Conclusively, the gold nanoparticle can penetrate into renal cell. This is the first report on this observation, and further implies the possibility of other nanoparticle nephrotoxicity in the present nanomaterial era.

Synthesis of stilbene crown ether p-tert-butylcalix[4]arenes

Photo-switchable calixarene crown ether derivatives were synthesized in order to control the ring sizes and shapes of ionophores by isomerization between two different geometrical isomers. Five stilbene crown ether calix[4]arenes were prepared via McMurry coupling of the corresponding bisbenzaldehyde–calix[4]arene derivatives. The coupling reactions yielded both cis- and trans-stilbenes from o- and m-bisbenzaldehydes while only the cis-isomer was obtained from the reaction of the p-isomer. Unlike diazobenzene analogues, the stilbene crown ether calix[4]arene derivatives did not undergo thermal isomerization. Nevertheless, the isomerization of all synthesized stilbene crown ether calix[4]arenes can be photochemically induced.

Gold nanoparticle as an alternative tool for a urine pregnancy test.

OBJECTIVE The urine pregnancy test is an easily available diagnostic test in the present day and is routinely performed. The test is based on an immunochromatography technique. Here, we used an advanced nanomedicine technique for modification of the urine pregnancy test. MATERIALS AND METHODS The preparation of gold nanoparticle solution in this study followed the standard method. We performed an experiment on both pregnancy-positive and -negative urine samples. First, a mixture with an equal amount (500 microliters) of gold nanoparticle solution and urine sample was prepared. Then, it was further tested for pregnancy by the urine pregnancy test strip. RESULTS The pregnancy-positive mixture became pink, while the pregnancy-negative mixture became gray. The urine pregnancy test strip for a positive mixture had two lines, while the negative mixture had one line. CONCLUSION This application can help the diagnosis of pregnancy and can be an alternative method for a urine pregnancy test. To our knowledge, this is the first report on this application.

Effect of gold nanoparticle on the microscopic morphology of white blood cell

Background:  In medicine, there is limited knowledge on the toxicity of nanoparticles. In medicine, there has been limited knowledge on the effect of nanoparticles on the white blood cell.

Gold nanoparticle as an alternative tool for urine microalbumin test: the first world report.

Urine microalbuminuria is a common indicator for occult preclinical nephropathy. At present, urine microalbumin test is routinely performed by clinical chemistry test. Here, the authors used the advanced nanomedicine technique for modification of the urine microalbumin test. Materials and methods. The preparation of gold nanoparticle solution in this study was according to the standard method reported by Frenkel et al. The author performed an experiment on both microalbumin positive and negative urine samples. First, the mixture between equal amount (500 microliter) of gold nanoparticle solution and urine sample was prepared. Results. The microalbumin-positive mixture becomes purple, while the pregnancy-negative mixture becomes gray. Conclusion. This application can help the diagnosis of microalbumin and can be the alternative way for this urine microalbumin test. This is the first world report on this application.

Picolinic diamide pincers for transition metal complexation and their electrochemical properties

A series of novel molecular pincers was successfully synthesised by a copper-free Sonogashira coupling methodology. Complexation of the pincers with Cu(II), Ni(II) and Co(II) was performed in the presence of triethylamine. The formation of the desirable pincer ligands and complexes was confirmed by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and mass spectrometry. Electrochemical properties of the complexes of the target pincer dimers investigated by means of cyclic voltammetry suggested that the pincer dimers should be able to serve as an electron donor for phenyl-C61-butyric acid methyl ester and as an electron acceptor for poly(3-hexylthiophene) in bulk heterojunction solar cells.