Polymer based microfabrication and its applications in optical MEMS and bioMEMS

Due to its ease of fabrication, low cost and great variety of functionalities, polymer has become an important material in microfabrication. MEMS devices with polymer as the structure material have found applications in various fields, especially in BioMEMS and optical MEMS. In this dissertation, three polymer based microfabricated devices/components have been developed and tested. Various polymer based fabrication techniques, such as high aspect ratio SU-8 photolithography, three dimensional polydimethylsiloxane (PDMS) soft lithography, multi-layer soft lithography and PDMS double casting technique have been developed/studied and employed in the device fabrication process. The main contribution of this dissertation includes: (1) Developed two novel methods for the fabrication of out-of-plane microlens. The PDMS and UV curable polymer (NOA73) replication technique made possible the fast replication of out-of-plane microlens and broaden the lens material selection. The in-situ pneumatical microlens fabrication technique, on the other hand, provides feasible method to integrate out-of-plane microlens into microfluidic chips requiring minimal design footprint and fabrication complexity. (2) Design, fabrication and test of a microchip flow cytometer with 3-D hydrofocusing chamber and integrated out-of-plane microlens as on-chip optical detection component. The developed micro flow cytometer offers 3-D hydrofocusing like conventional cytometer cuvette, and has on-chip microlens for optical signal collection to improve the detection efficiency. With the latest design improvement, the hydrofocusing chamber can focus the sample stream down to less than 10 m in diameter in both vertical and horizontal directions. (3) Development of a PDMS microchip based platform for multiplex immunoassay applications. Integrated micro valves were employed for manipulation of fluidic reagents in the microchannel network. PDMS surface was used as the solid phase substrate for immuno-reactions. Preliminary results showed that, even with low cost polyclonal goat anti-mouse IgG as the reporter antibody, the detection limit of goat mouse IgG can reach as low as 5 ng/mL (about 33 pM). With the continuous advance in microfabrcation technique and polymer science, polymer based microfabrication and polymer MEMS devices will keep to evolve. In the future, more work needs to be done in this field with great potential and endless innovations

Design, synthesis and development of PDE5 inhibitors

This research project is concerned with the design, synthesis and development of new phosphodiesterase 5 (PDE5) inhibitors with improved selectivities and lower toxicities. Two series of a 5 member and a 6 member ring fused heterocyclic compounds were designed, and synthesized. By alteration of starting materials and fragments, two virtual libraries, each is consisted of close to hundred compounds, were obtained successfully. The screening of sexual stimulation activity with rabbits demonstrated both groups of compounds were able to stimulate rabbit penile erection significantly. The following toxicity studies revealed 2-(substituted-sulfonylphenyl)-imidazo [1,5-a]-1,3,5-triazine-4-(3H)-one group possessed an unacceptable toxicity with oral LD50 about 200mg/kg; while 2-(substituted-sulfonylphenyl)-pyrrolo[2,3-d]pyrimidin-4-one group showed an acceptable toxicity with oral LD50 over 2000mg/kg. The continued bioactivity studies showed yonkenafil, the representative of 2-(substituted-sulfonylphenyl)-pyrrolo[2,3-d]pyrimidin-4-one group, has a better selectivity towards PDE5 and PDE6 than sildenafil and a better overall profile of sexual stimulation on animals than sildenafil. Chronic toxicity studies of yonkenafil further confirmed yonkenafil did not cause any serious side effect and damage on animal models and most actions were explainable. Based on evidences of the above studies, yonkenafil were recommended to enter clinical trials by the regulation authority of China, SFDA. Currently yonkenafil has been through the Phase I clinical trials and ready to progress into Phase II. Hopefully, yonkenafil will provide an alternative to the ED patients in the future

Estimating sample-specific regulatory networks

Biological systems are driven by intricate interactions among the complex array of molecules that comprise the cell. Many methods have been developed to reconstruct network models of those interactions. These methods often draw on large numbers of samples with measured gene expression profiles to infer connections between genes (or gene products). The result is an aggregate network model representing a single estimate for the likelihood of each interaction, or "edge," in the network. While informative, aggregate models fail to capture the heterogeneity that is represented in any population. Here we propose a method to reverse engineer sample-specific networks from aggregate network models. We demonstrate the accuracy and applicability of our approach in several data sets, including simulated data, microarray expression data from synchronized yeast cells, and RNA-seq data collected from human lymphoblastoid cell lines. We show that these sample-specific networks can be used to study changes in network topology across time and to characterize shifts in gene regulation that may not be apparent in expression data. We believe the ability to generate sample-specific networks will greatly facilitate the application of network methods to the increasingly large, complex, and heterogeneous multi-omic data sets that are currently being generated, and ultimately support the emerging field of precision network medicine

Developing Magnetic Material for Remediation of Aquatic Nitrogen Pollution in Water Facilities

Natural organic matter affect water environmental security and posed a potential threat to human health, and thus it has long been considered as a key index to evaluate water treatment performance. Dissolved organic nitrogen is one of the NOM, which produces some disinfection byproducts having more toxic than those carbon-based materials. Coagulation is a key unit of drinking water purification and has received wide attention. However, conventional flocculation technology on removal of DON is so poor that we have to seek more effective improving measurement. The combined use of conventional flocculant and organic polymer can improve treatment efficiency to a certain extent, and enhanced coagulation can also improve the DON removal rate, but their DON removal performance is still not dreamful. At present, there is a lack of systematic research on flocculation to remove DON. Although some achievements have been made, there is still a big gap between the preparation technology of flocculant and the goal of efficient removal of DON in water.For treatment of secondary effluent of industrial wastewater, some studies show that the use of Fe3O4 mainly has the effect of accelerating separation, but the adsorption effect is not good. However, with the synergistic flocculation of amino functionalized Fe3O4 it has a good effect on removing water protein, polysaccharide and humic acid, which can meet the water quality discharge standard and reduce the dosage of flocculant. The above results show that functional nanoparticle materials are of great significance to improve the adsorption and flocculation performance. Therefore, the functional modification of magnetic nanoparticles plays an important role

Sealing Leakage of Earth Dam by Concrete Diaphragm

Some seriously cracked and leaked earth dams in China have been successfully strengthened by the cast-in-situ concrete diaphragm at or near the dam axis through the dam embankment. The diaphragm is enabled to seal the leakage through concentrated seepage path in the earthfill resulted from the large voids or the cracks in cohesive earthfill as well as the leakage through the alluvium in dam foundation. The effectiveness of this strengthening method depends on the correct determination of the major seepage channels. Serious longitudinal cracks have occurred in some dams during excavating the slurry trenches and pouring concrete into them owing to the hydraulic fracturing effect of the drilling fluid and liquid concrete. After some modification of the construction technique the strengthening work was carried out smoothly. The cracks were closed after completion of construction work and the contact between the earthfill and diaphragm was satisfactory

Characterization of miniature fiber-optic Fabry-Perot interferometric sensors based on hollow silica tube

Sejatinya, Islam Nusantara bukanlah sesuatu yang baru. Penebalan kata “Nusantara” yang dikawinkan dengan “Islam” bukan hanya menegaskan nama, melainkan juga karakter untuk menunjukkan corak atau warna dari sebuah entitas yang heterogen. Keragaman sebagai salah satu tipologi Islam Nusantara adalah buah dari pergumulan panjang antara agama dan budaya; antara teks dengan konteks yang saling melengkapi satu sama lain sehingga menelurkan Islam yang ramah, inklusif dan fleksibel. Berangkat dari pijakan epistemologis dan historis, artikel ini coba menyuguhkan diskursus lama yang kembali mencuat di seputaran pertengahan tahun 2015 seiring dengan dihelatnya Muktamar dua ormas besar: NU dan Muhammadiyah. Hadirnya artikel ini sebetulnya juga ingin menjawab kasak-kusuk yang menuding bahwa Islam Nusantara hanya identik dengan kaum Nahdliyin. Sehingga term Islam Nusantara tidak lain dianggap sebagai nama baru dariIslam tradisionalis.Essentially, Islam Nusantara isn’t a new phenomenon. Bolding of both “Nusantara” with “Islam” not only affirmation about name but also character to show type or colour from the heterogenous entity. Diversity as one of Islam Nusantara typology is the result of a long struggle between religionand culture; between text and context that complement each other so that Islam spawned a friendly, inclusive and flexible. Start from the historical and epistemological approach, this article try to presents a classical discourse the back sticking around mid-2015 in line with the holding of the congress two major organizations: NU and Muhammadiyah. Actually, the presence o fthis article is also want to answer the rumors that accuse Islam Nusantara only synonymous with the Nahdliyin. Thus, Islam Nusantara considered as the new name of traditionalism Islam.</p

Rethinking the Pipeline of Demosaicing, Denoising and Super-Resolution

Incomplete color sampling, noise degradation, and limited resolution are the three key problems that are unavoidable in modern camera systems. Demosaicing (DM), denoising (DN), and super-resolution (SR) are core components in a digital image processing pipeline to overcome the three problems above, respectively. Although each of these problems has been studied actively, the mixture problem of DM, DN, and SR, which is a higher practical value, lacks enough attention. Such a mixture problem is usually solved by a sequential solution (applying each method independently in a fixed order: DM $\to$ DN $\to$ SR), or is simply tackled by an end-to-end network without enough analysis into interactions among tasks, resulting in an undesired performance drop in the final image quality. In this paper, we rethink the mixture problem from a holistic perspective and propose a new image processing pipeline: DN $\to$ SR $\to$ DM. Extensive experiments show that simply modifying the usual sequential solution by leveraging our proposed pipeline could enhance the image quality by a large margin. We further adopt the proposed pipeline into an end-to-end network, and present Trinity Enhancement Network (TENet). Quantitative and qualitative experiments demonstrate the superiority of our TENet to the state-of-the-art. Besides, we notice the literature lacks a full color sampled dataset. To this end, we contribute a new high-quality full color sampled real-world dataset, namely PixelShift200. Our experiments show the benefit of the proposed PixelShift200 dataset for raw image processing.Comment: Code is available at: https://github.com/guochengqian/TENe