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.
First photochromic diarylethenes with cyclohexenone ethene "bridge"
Photochromism is determined as reversible transformation between two chemical species, induced by action of light [1]. Herewith, initial form and photoinduced isomer have different properties, first of all, spectral. The phenomenon is attractive for the design of hi-tech materials for different applications, including optical memory elements and molecular switches. Diarylethenes are the most promising class of organic photochromic compounds due to outstanding thermal stability of both isomers and high photostability [2, 3]. Photochromism of diarylethenes explained by reversible electrocyclic reaction of hexatriene system, provoked by UV light, back reaction is induced by visible light. In this work we have proposed a new class of photochromic diarylethenes with cyclohexenone ethene “bridge” 4. The key stage of the synthesis is “one-pot” reaction of ketoesters 1 and chalkones 2 in ethanol in the presence of sodium ethoxide that includes Michael reaction and subsequent intramolecular condensation of the resulting product. The final decarboxylation of semi-product 3 results in target diarylethenes 4. We have prepared a wide range of photochromic diarylethenes with thiophene, oxazole, imidazole and benzene derivatives as aryl moieties. The spectral characteristics of compounds obtained have also been discussed.
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.
永恆的旋轉木馬
本研究作品主要在探討「平面上各種曲線內關於相鄰等角割線段的新的不變量」與「空間中特殊圓錐曲面的特殊等角割線段的新的不變量」。 若圓錐曲線、蚶線等曲線中有相鄰等角的 條割線段，則這n條割線段之m次方和為定值。在圓錐曲線中這些割線段的交點可以是焦點、曲線內任意點，在蚶線中則為基點。甚至經由反演，還能將此性質推廣至直線上。 研究最後擴及至空間，先考慮特殊橢圓、拋物、雙曲球面，其一焦點為F，將正N面體VN之重心G與F重合，使得VN以F為旋轉中心任意旋轉，此時由F對VN之各頂點做射線交圓錐曲面於 PN，則FPN之倒數m次方和為定值，其中u=1,...,n，N=4, 6, 8, 12, 20 。