3^rd World Chemistry Conference September 11-12, 2017 Dallas, Texas, USA

Biography:

Mihaela C Stefan received her Ph.D. degree in Chemistry from Politehnica University Bucharest. She joined the Department of Chemistry at the University of Texas at Dallas in 2007 and was promoted to Associate Professor in 2013. She has received a joint appointment in the Bioengineering Department in 2014. She received the NSF Career Award in 2010, the NS&M Outstanding Teacher Award in 2009 and 2017, the Inclusive Teaching Diversity Award in 2012, President’s Teaching Excellence Award in 2014, and the Provost’s Award for Faculty Excellence in Undergraduate Research Mentoring in 2015. Her research group is developing novel polymeric materials for organic electronics and drug delivery applications.

Abstract:

Furan and its derivatives are promising alternative building blocks for the synthesis of semiconducting polymers due to their properties such as smaller heteroatom size, a more electronegative heteroatom, and larger dipole moment. Conjugated polymers synthesized from furan show a higher degree of conjugation with reduced twisting between adjacent units, smaller π-stacking distance, and improved solubility in organic solvents. Despite research on polymers constructed from furan derivatives gaining attention, conjugated polymers from furan only are still scarce. We reported a conjugated polymer, poly(4,8-bis(5-(2-ethylhexyl)furan-2-yl)benzo[1,2-b:4,5-b']difuran-alt-2,5-didodecyl-3,6-di(furan -2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione), P(BDF-FDPP), for organic solar cells. The smaller oxygen atom in furan of P(BDF-FDPP) resulted in a planar conjugated backbone with negligible torsion (dihedral angle < 0.10) determined by density functional theory. P(BDF-FDPP) exhibited broad absorption up to 940 nm with HOMO and LUMO located at -5.19 eV and -3.63 eV, respectively. Power conversion efficiency (PCE) of 5.55% with a high fill factor (FF) of 0.73 was measured for the devices fabricated using diphenyl ether (DPE) as an additive. The considerable change in photovoltaic performance of the devices fabricated with or without additives was investigated with grazing incident wide-angle X-ray scattering, and transmission electron microscopy experiments. The preferential face-on orientation of P(BDF-FDPP) and sophisticated interpenetrated network for P(BDF-FDPP)/PC71BM blend films enabled relatively good PCEs and high FF in solar cell devices.

Biography:

John Hardy undertook his undergraduate and doctoral studies chemistry in Bristol and York in the UK. Thereafter he undertook 10 years of interdisciplinary postdoctoral research (in Pharmacy, Biomedical/Chemical Engineering and  Materials Science ) in France, Germany, Northern Ireland and the USA before returning to the UK for a 50^th Anniversary lectureship in materials chemistry at Lancaster University. He has received a variety of awards from charities, governmental bodies and industry, and serves on the editorial board of a number of journals including Future Science OA and the International Journal of Molecular Sciences.

Abstract:

Stimuli-responsive instructive biomaterials are particularly attractive for the treatment of a variety of conditions either via the controlled delivery of precise quantities of drugs at specific locations and times, or indeed delivery of a cue (e.g. chemical, electrical, light, mechanical, topographical) to the cells interacting with the material (e.g. in the form of a medical device or tissue scaffold).

Materials responding to stimuli such as enzymes, light, pH, temperature, ultrasound and electric/magnetic fields have been developed for use as drug delivery devices, medical devices and tissue scaffolds. An interesting research area is the development of materials capable of controlling either cell behavior or the delivery of drugs in response to electricity, light and magnetism.

Here we report the development of polymer-based materials that enable the delivery of drugs in response to electrical fields, light and magnetism; the tuneable properties of the materials make them attractive components of electroactive/photoresponsive biomaterials that when non-degradable have potential application for long term medical devices (e.g. bioactive coatings, electrodes, tools), and when degradable have potential application for short term applications (e.g. drug delivery or tissue engineering). An overview of these developments will be presented.

Biography:

Melikhan Tanyeri has received his PhD in Physics from University of California, Davis, where he developed chemical and biological sensor platforms based on optical resonances in microcavities. He has moved to University of Illinois at Urbana-Champaign for his Postdoctoral training, where he has developed a new class of microfluidic tools for trapping and manipulating micro and nanoscale particles. During 2013-2016, he was an Assistant Professor in the Department of Electrical Engineering at Istanbul Sehir University in Turkey, where his group was pursuing research at the interface of applied Physics, Engineering and Medical Sciences. He is currently working as a Research Scientist at the Institute of Molecular Engineering at the University of Chicago, developing tools for single cell analysis towards applications in Immunology. His research interests include optical biosensors, imaging and spectroscopy, molecular and cellular biophysics, microfluidics and bioMEMS.

Abstract:

We present a novel flow-based method to study the dissolution of individual microdroplets in aqueous solutions. For most two-phase systems, liquid-liquid miscibility is characterized by a small and often negligible quantity, thereby leading to the assumption that many emulsion systems are immiscible. Similarly, during emulsion generation, vast quantities of aqueous microdroplets are produced in host oil-based solutions and are considered stable for long periods of time. A careful study of oil-water miscibility at the micro scale will provide valuable insight into these systems. In this work, we report a new method enabling quantitative analysis of dissolution of an individual microdroplet in the immiscible medium. We observed that micro droplets, normally immiscible in host medium, dissolve substantially under planar extensional flow conditions. Furthermore, we developed a model accurately capturing the dissolution dynamics of individual droplets in the immiscible medium. We observed dissolution of individual oil micro droplets in aqueous solutions under planar extensional flow. Specifically, we confined single microdroplets at the stagnation point of a planar extensional flow generated at the junction of two perpendicular microchannels. We quantitatively analyzed micro droplet dissolution by acquiring consecutive images of a hydrodynamically-trapped microdroplet, and by measuring the change in average droplet diameter as a function of time. We demonstrated that dissolution of the oil phase in host aqueous solution could be substantial under laminar flow. In the absence of flow, the size of the oil microdroplets does not significantly change over a long period of time, as expected. We developed a model to explain flow-enhanced dissolution of micro droplets under planar extensional flow. This study demonstrates flow-induced dissolution of immiscible fluid-fluid systems at the micro scale and shows that the dynamics of dissolution can be predicted accurately by a numerical model. This novel method will enable fast and precise measurement of solubility and diffusion coefficients for immiscible two-phase (liquid-liquid and gas-liquid) fluid systems with potential applications towards food, cosmetic and pharmaceutical industries.

Biography:

Yixin Ren is a McNair scholar. He received his BS degree in Chemistry & Medicinal Chemistry from the University at Buffalo in 2012. He subsequently completed his M.S. degree in chemistry from the Illinois State University in 2014 under the supervision of Lisa F. Szczepura. He is currently working on his Ph.D. in chemistry at the University of Texas at Dallas under supervision of Mihaela C. Stefan. His current research endeavors are focused on neodymium-based catalysts for polymerization of dienes and vinyl monomers and ring opening polymerization of cyclic esters.

Abstract:

Neodymium-based catalysts bearing phosphate ligands NdCl3·3L (L = triethyl phosphate (TEP) or tris(2-ethylhexyl) phosphate (TEHP) were successfully synthesized. The ring opening polymerization (ROP) of ε-caprolactone (ε-CL) initiated with these catalysts in the presence of a series of alcohols were performed yielding polymers with the narrow polydispersity index (PDI = 1.22 to 1.55) and controllable molecular weight. An important result from the kinetic studies revealed that the sterically bulkier ligand TEHP, as compared to TEP ligand significantly increased the rate for ROP of ε-CL. Di-block copolymers poly(ε-CL)-block-poly(D,L-lactide) via sequential monomer addition were successfully synthesized demonstrating the living nature of the catalytic system. 

Biography:

Celyna K Rackov has completed her PhD degree in Chemical Engineering at the University of Sao Paulo (USP-Brazil) in 2014, in Environmental Technologies, with a scholarship from a Brazilian Program. Meanwhile, she has participated in a Doctorate fellowship at the University of Texas at Arlington. Between December 2015 to May 2016, she has worked as Postdoctoral researcher at USP in environmental area. She is remotely advising students from Chemical Engineering Department of the Federal University of Rio Grande do Norte, Brazil. From October to December 2016, she was teaching Chemistry classes in the Natural Sciences Department of the Dickinson State University (DSU - North Dakota, USA), as a special Faculty appointment. Since January 2017, she is working as Faculty in Chemistry at El Centro College, Dallas - TX.

Abstract:

Emerging pollutants have been subject of a worldwide study because they present a potential threat to the environment and human health, because of their continuous entry into the environment. In this context, researches are being developed with the aim of improving the methods for these pollutants elimination or reduction. Through the Advanced Oxidative Process (AOP) radicals are generated to oxidize the chemicals present in effluents. Thus, this work focuses on the treatment of the synthetic hormone 17α-ethinylestradiol in aqueous systems, using traditional methods: activating the oxidant through pH, temperature and iron ions compared to the innovative method that activated the persulfate by the catalyst (Modified Diatomite). According to the results, it can be concluded that the innovative activation method, using modified diatomite, was more efficient than the traditional methods, achieving a 98% removal of EE2 in 90 minutes of reaction.

Biography:

Beena Jose has completed her Ph.D. in Chemistry from the University of Calicut in 2005. She has published 36 papers in various reputed national and international journals and authored one book. Her area of specialization is Natural Products Chemistry. Currently, she is working as an Assistant Professor in Chemistry, Vimala College, Thrissur, Kerala, India. She has presented papers in India and abroad. As a part of International Fellowship Program, she has been selected as an International Visiting Research Scholar at the Jesuit School of Theology (JST) of Santa Clara University, the USA for the year 2014-15. She is the recipient of University Grants Commission’s (UGC) Major and Minor research projects. Her area of interests are phytochemical analysis and structural elucidation of the compounds isolated from plants.

Abstract:

Wrightia tinctoria R. Br. belongs to family Apocynaceae commonly called as “Jaundice curative tree” in South India. In Siddha system of medicine, it is used for psoriasis and other skin diseases. In the present study various secondary metabolites from the leaf and bark of Wrightia tinctoria (Pala Indigo) were isolated by column chromatography and characterized by spectral analysis (¹H NMR, ¹³C NMR, IR, Mass Spectrum). The antibacterial and antifungal activities of the plant extracts against various pathogenic bacteria such as Bacillus cereus, Enterobacter faecalis, Salmonella paratyphi, Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens and antifungal activity against two fungi namely Aspergillus niger and Penicillium chrysogenum were evaluated by agar well diffusion method. The anticancer potential of Wrightia tinctoria was studied both in vitro and in vivo. Anti-tumor properties of Wrightia tinctoria could be linked with the presence of antioxidants and cytotoxic activity. These outcomes indicate the possible potential use of Wrightia tinctoria as anti-tumor agent.

Biography:

Abstract:

 Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells, which on treatment with hydrofluoric acid yielded hollow core-shells. Whereas modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities without any competition. Therefore, entire work in this article is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells, which imparted indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL^-1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination. 

Biography:

Abstract:

The pharmaceutical demand for plant-based colchicine is increasing because it is an effective FDA-approved gout medicine that also has potential for cancer therapeutics due to its ability to bind to microtubules and halt cell division. Understanding the biorhizome developmental genes are necessary to improve the biomanufacturing of colchicine. RNA-Seq was used to identify the rhizome developmental genes from Gloriosa superba and Colchicum autumnale. The transcriptome of both species were compared against NCBI and Swissprot protein databases. Python scripts were utilized to parse the transcriptome. Bioinformatics analysis revealed 60927 assembled multiple-tissue transcripts of C. autumnale represented 21948 unigenes and G. superba has 32312, which represented 15089 unigenes in known plant specific gene ontology (GO). Further GO analysis was used to identify known rhizome-specific and developmental genes in G. superba. This study could provide a foundation to enhance the biorhizome-based colchicine biomanufacturing in G. superba. 

Biography:

Abstract:

Colchicine is a FDA-approved plant-based alkaloid that is commonly used to treat gout. It has also been proven to be beneficial in cardiovascular diseases and its antimitotic properties make it a promising cancer treatment. Traditionally, the natural isomer of colchicine is exacted from Gloriosa superba, which was initially isolated from Colchicum autumnale. The biosynthetic pathway of colchicine is not yet characterized, and the pathway genes and mechanisms must be elucidated to improve colchicine production.  G. superba and C. autumnale transcriptomes were analyzed and compared against NCBI and Swissprot protein databases to identify the biosynthetic pathway genes. The annotation data of these transcriptomes revealed that there were 60927 assembled multi-tissue transcripts of C. autumnale, which represented 21945 unigenes. Additionally, G. superba has 32312 assembled multi-tissue transcripts which represented 15088 unigenes in known plant-specific Gene Ontology (GO). Gene annotation and pathway mapping data will be presented. 

Biography:

Abstract:

Gloriosa superba is a commercial source of the pharmaceutical colchicine. Colchicine is one of the primary sources of treatment for gout. The balloon type bubble reactor (BTBR) has been successfully used to biomanufacture bioactive small molecules. Colchicine production can be improved by understanding the fluid mechanics inside this reactor, which primarily depends on several parameters such as reactor working volumes, diameter of the sparger, flow rate, viscosity, surface tension, density of the fluids, and nutrient volume fractions. Our initial bioimaging study suggests that in 4L BTBR at low air injection rate the flow ascends up a fairly straight vertical path, concentrating mostly toward the center of the reactor. However, at higher injection rates, a more chaotic flow forms. The post processed images reveal that the flow patterns inside the reactor vary, as positive and negative vorticity zones. We will present the clockwise/counter-clockwise directions of the dimensionless mapping of fluid dynamics data. This analysis will not only address the geometric patterns of mixing, but will also apply to the nature of liquids, solutions, and injection gases with various combinations of density, viscosity, and surface tension that will eventually improve the colchicine biomanufacturing design process. 

Biography:

Xuyi Cai has his expertise in Groundwater Chemistry and Atmospheric Chemistry. His research is involved in aerosol thermodynamics, secondary organic aerosol formation from biogenic and authropogenic volatile organic compounds, groundwater pollution in north China, and geochemical modelling. He has published his papers in several journals.

Abstract:

Statement of the Problem: Riparian vegetated buffer strips (RVBS) are widely constructed in the world to reduce the nutrient flux in surface runoff into surface water bodies to curb the development of eutrophication. However, which kinds of vegetation composition may reduce the nutrient flux in surface runoff more effectively is still an open problem. The purpose of this study is to determine whether plant species significantly influences its floor soil denitrification potentials for a planted forest.

Methodology & Theoretical Orientation: Two planted forests with different compositions in similar soil conditions in Zhushan Bay, in the buffer zone of Taihu Lake were chosen as the vegetation buffer strips for the comparison of their soil denitrification potentials. One is a composite forest composed of poplar trees, shrubs and herbs, named the poplar and shrub forest (PSF), and the other is composed of poplar and herbaceous plants, named the poplar forest (PF). Their floor surface runoff, the soil water and groundwater below their floor were monitored for one-year, and their soil denitrification potentials were compared. Laboratory DOC (dissolved organic carbon) leaching experiments of plant leaf and root were conducted which occurs in the study area.

Findings: The research results show that: There is a maximum value for the measured denitrification potentials around the depth of 40 cm in the vertical soil profiles for both planted forests, coincided with lower values for DO concentration and Eh at the same depth, proving the existence of a coupled nitrification-denitrification layer; in the vertical soil profiles for both planted forests, all the maximum values for the soil denitrification potentials and the numbers of denitrification bacteria in these two forests occur around the depth of 40 cm, demonstrating the existence of an active denitrification layer (composed of biogeochemical hot-spots) around the depth of 40 cm, which is closely related to the root system of grass vegetation for both forests; at the same depth, the soil denitrification potentials for PSF are twice of those for PF, however, there is no significant difference for the actual denitrification rates for the soils in both forests, which are limited by the concentration of nitrate in soil water and plant species have important influence on soil denitrification potentials.

Conclusion & Significance: Vegetation composition is an important influence factor for RVBS systems to remove nitrate in surface runoff and groundwater.