Fabrication of Hydrophobic Coatings Using the Sol-Gel Method
The aim of our research is to produce superhydrophobic coatings on both glass and cloth substrates in order to achieve high contact angles and low sliding angles for self-cleaning. In addition, we aim to modify these coatings to be as transparent as possible so as not to interfere with the aesthetics of the objects which will be coated. To achieve this goal, we synthesised a solution using 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (a type of FAS), silica nanoparticles (SiO2), tetraethyl orthosilicate (TEOS), (3-glycidyloxypropyl) trimethoxysilane (Glymo) and deionised water. Using the convenient sol-gel method, coatings of 20% and 30% by weight of FAS-SiO2 nanoparticles were prepared on glass and cotton substrates. It was found that coatings containing 30% by weight of FAS-modified SiO2 nanoparticles on glass slide produced coatings with water contact angle as high as 162.8° and sliding angle as low as 4°. It can also be seen that for glass substrates, the hydrophobicity increased with an increase in percentage of FAS-modified SiO2 nanoparticles. Although the highest percentage transmittance was about 30%, texts and pictures beneath the coated glass slides were clearly readable. The cotton substrates also exhibited excellent hydrophobicity, with a water contact angle of 150° and sliding angle of 22°. Furthermore, the substrates showed good retention of colour and durability after simulated washing and 72 hours of ultraviolet (UV) weathering chamber test. These results show that the effects of washing and UV on the important properties of the cloth were insignificant.
Automated Illustration of Text to Improve Semantic Comprehension
Millions of people worldwide suffer from aphasia, a disorder that severely inhibits language comprehension. Medical professionals suggest that individuals with aphasia have a noticeably greater understanding of pictures than of the written or spoken word. Accordingly, we design a text-to-image converter that augments lingual communication, overcoming the highly constrained input strings and predefined output templates of previous work. This project offers four primary contributions. First, we develop an image processing algorithm that finds a simple graphical representation for each noun in the input text by analyzing Hu mo-ments of contours in images from The Noun Project and Bing Images. Next, we construct a da-taset of 700 human-centric action verbs annotated with corresponding body positions. We train support vector machines to match verbs outside the dataset with appropriate body positions. Our system illustrates body positions and emotions with a generic human representation created using iOS’s Core Animation framework. Third, we design an algorithm that maps abstract nouns to concrete ones that can be illustrated easily. To accomplish this, we use spectral clustering to iden-tify 175 abstract noun classes and annotate these classes with representative concrete nouns. Fi-nally, our system parses two datasets of pre-segmented and pre-captioned real-world images (Im-ageClef and Microsoft COCO) to identify graphical patterns that accurately represent semantic relationships between the words in a sentence. Our tests on human subjects establish the system’s effectiveness in communicating text using im-ages. Beyond people with aphasia, our system can assist individuals with Alzheimer’s or Parkin-son’s, travelers located in foreign countries, and children learning how to read.
An investigation of the inhibitory potential of Dronedarone on CYP2J2 mediated astemizole metabolism
Dronedarone is an anti-arrhythmic drug approved in 2009 for paroxysmal and persistent atrial fibrillation. It is less toxic than its predecessor Amiodarone as it does not cause systemic toxicity but has the same pharmacological activity. However the administration of dronedarone to permanent AF and heart failure patients leads to increased risk of stroke and cardiac death. The exact mechanism of the toxicity is currently unknown. Extrahepatic Cytochrome P450 enzymes play a dominant role in organ-specific drug metabolism and toxicity. Cytochrome P450 2J2 (CYP2J2) enzyme, a predominant enzyme found in human cardiac myocytes, metabolizes endogenous arachidonic acid (AA) into epoxyeicosatrienoic acids (EETs) which play an important role in maintaining normal cardiac physiology. Inhibition of CYP2J2 and perturbation of AA metabolic pathway could result in exacerbation of cardiac failure. This research aims to find out whether dronedarone inhibits CYP2J2 in a suitable cell model (H9C2) using astemizole as a probe substrate. Our in-house studies using recombinant CYP2J2 enzyme have shown that dronedarone potently inhibits CYP2J2. Rat myoblast cells (H9C2) will be seeded in 12-well plate and differentiated for 4 days. The cells will be then treated with different concentrations of astemizole and incubated for 24 h. The cells will then be harvested, lysed, and the cell lysate will be analyzed using liquid chromatography-mass spectrometry (LCMS). Using multi-reaction monitoring (MRM) on the LCMS, astemizole concentration as well as its CYP2J2-specific metabolite O-desmethylastemizole concentrations will be measured. The presence of O-desmethylastemizole confirms the metabolism of astemizole by CYP2J2 in H9C2 cells. By plotting a Michaelis-Menten kinetics curve, we will be able to determine the Michaelis constant (KM) and maximum rate of reaction (Vmax). H9C2 cells will be then treated with fixed concentration of astemizole while varying the dronedarone concentration. A decrease in metabolite O-desmethylastemizole conce ntration, indicates inhibition of CYP2J2 metabolism by dronedarone. Using this data, Lineweaver-Burke graph will be plotted, to determine the mode and potency of the inhibition. Our preliminary studies showed that the KM value was 2.7μM. This study will be useful in understanding if dronedarone inhibits CYP2J2 which may lead to clinically significant drug-drug interactions, one of the dangers of polypharmacy. Finally this study will shed a new light on the mechanisms for dronedarone mediated cardiac failure exacerbation.
Findings of new oscillations in BR reaction
The Briggs Rauscher reaction, i. e., BR reaction, which is one of the oscillation reactions, produces iodide ion and iodine repeatedly. Continual color changes of the solution from colorless to deep blue, and vice versa, are observed during the reaction due to the so-called “iodine test” reaction. In this work, we studied the effects of the presence of the redox active indicators on the oscillation behavior of the BR reaction. To the reaction mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch, which are used for the general BR reaction as added a redox active reagent (indicator). Then, the changes in color and voltage of the reaction solution were recorded by a photosensor of the LEGO MINDSTORMS and a voltmeter using Pt electrodes. Under general reaction conditions, the oscillation reaction continued for ca. 5 minutes, including 18 times of oscillations. When an indicator, such as BTB, was added instead of starch to the reaction solution, splits of the voltage wave were observed, which should be a kind of new oscillation. Moreover, we found that the addition of K3[Fe(CN)6], which exhibits high redox activity, in the reaction solution instead of starch made the life-time and the numbers of the oscillation in the reaction greater by 3 times (14 min.) in time and more than 4 times (81 times) in the frequency. It’s also a kind of new oscillation. These results suggested that the oxidation-reduction reactions by the addition of ferricyanate ion effectively promotes the redox process of iodine and iodide ion. The experiments we wrote above were conducted without starch. Thus, as a reference, we conducted the same experiments under the presence of starch and got interesting results. We also studied the effects of K4[Fe(CN)6], suggeting that not only redox reaction between ferricyanide and ferrocyanide ion, but also the redox reaction with BR solution should occur in these reactions.