Nanoscale confinement biogenetic silica template-based electrical biosensor assay offers the user the ability to detect and quantify the biomolecules. Diatoms have been demonstrated as part of a sensor. The sensor works on the principle of electrochemical impedance spectroscopy. When specific protein biomarkers from a test sample bind to corresponding antibodies conjugated to the surface of the gold surface at the base of each nanowell, a perturbation of electrical double layer occurs resulting in a change in the impedance.
Diatoms are also a new source of inspiration for the design and fabrication of nanostructured materials. Template-directed deposition within cylindrical nanopores of a porous membrane represents an attractive and reproducible approach for preparing metal nanopatterns or nanorods of a variety of aspect ratios. The nanopatterns fabricated from diatom have the potential of the metal-enhanced fluorescence to detect dye-conjugated molecules.
Another approach presents a platform integrating biogenic silica nanostructures with micromachined silicon substrates in a micro
ano hybrid device. In this study, one can take advantages of the unique properties of a marine diatom that exhibits nanopores on the order of 40 nm in diameter and a hierarchical structure. This device can be used to several applications, such as nano particles separation and detection. This platform is also a good substrate to study cell growth that one can observe the reaction of cell growing on the nanostructure of frustule.
To achieve a sensing diameter of 1-2 nanometers, the diatom shells were used as substrates to perform ion-channel reconstitution experiments. The immobilized diatom shell was functionalized using silane chemistry and lipid bilayer membranes were formed. Functionalization of the diatom shell surface improves bilayer formation probability from 1 out of 10 to 10 out of 10 as monitored by impedance spectroscopy. Self-insertion of outer membrane protein OmpF of E.Coli into the lipid membranes could be confirmed using single channel recordings, indicating that nano-BLMs had formed which allow for fully functional porin activity. The results indicate that biogenic silica nanoporous substrates can be simulated using a simplified two dimensional geometry to predict the current when a nanoparticle translocates through a single aperture. With their tiered three-dimensional structure, diatom shells can be used in to form nano-lipid bilayer membranes and can be used in ion-channel reconstitution experiments similar to synthetic nanoporous membranes.
Most serial crystallography experiments have relied on delivering sample in the mother liquor focused into a stream by compressed gas. This liquid stream moves at a fast rate, meaning that most of the valuable sample is wasted. For this reason, the liquid jet can require 10-100 milligrams of sample for a complete data set. Agarose has been developed as a slow moving microcrystal carrier to decrease sample consumption and waste. The agarose jet provides low background, no Debye-Sherrer rings, is compatible for sample delivery in vacuum environments, and is compatible with a wide variety of crystal systems. Additionally, poly(ethylene oxide) which is amenable for data collection in atmosphere has been developed for synchrotron experiments. Thus this work allows sample limited proteins of difficult to crystallize systems to be investigated by serial crystallography.
Time-resolved serial X-ray crystallography (TR-SX) studies have only been employed to study light-triggered reactions in photoactive systems. While these systems are very important, most proteins in Nature are not light-driven. However, fast mixing of two liquids, such as those containing enzyme protein crystals and substrates, immediately before being exposed to an X-ray beam would allow conformational changes and /or intermediates to be seen by diffraction. As a model, 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS), has been developed for TR-SX. This enzyme initializes the first step of lipopolysaccharide synthesis by a net aldol condensation between arabinose-5-phosphate, phosphoenol pyruvate, and water. During this reaction, a short lived intermediate is formed and has been observed on a millisecond timescale using other methods. Thus KDO8PS is an ideal model protein for studying diffusion times into a crystal and short mixing times (<10 ms). For these experiments, microcrystals diffracting to high resolution have been developed and characterized.
To test the above proposition, I conduct the empirical analysis in three steps. In the first step, I investigate foreign banks’ management model by surveying 13 major foreign banks locally incorporated in Mainland China. The results suggest that these 13 foreign banks can be categorized into three distinct groups based on their management model: intergrators, customer-followers, and parent-followers. The results also indicate that intergrators have the highest level of localization while parent-followers have the lowest level of localization.
In the second step, I conduct DEA (Data Envelope Analysis) and CAMEL (Capital Adequacy, Asset Quality, Management, Earnings, Liquidity Analysis) to assess the operating efficiency of these 13 foreign banks. The assessment is conducted in two ways: 1) the inter-group comparison between foreign banks and local Chinese banks; 2) the intra-group comparison between the three distinct groups of foreign banks identified in the first step. The results indicates that the principal factor driving the operating efficiency of both local Chinese banks and foreign banks is the comprehensive technical efficiency, which includes both the quality of management and the quality of technical elements. I also find the uptrend of technical efficiency of the integrators is more stable than that of the other two groups of foreign banks.
Finally, I integrate the results from step one and step two to assess the relevance between foreign banks’ localization level and operating efficiency. I find that foreign banks that score higher in localization tend to have a higher level of operating efficiency. Although this finding is not conclusive about the causal relationship between localization and operating efficiency, it nevertheless suggests that the management model of the higher performing integrators can serve as references for the other foreign banks attempting to enhance their localization and operating efficiency. I also discuss the future trends of development in the banking industry in China and what foreign banks can learn from local Chinese banks to improve their market positions.
This report summarizes the development of a test stand used to measure the thrust or impulse of pulsed plasma thrusters (PPT). Currently, there is a lack of accessible, cost-efficient methods for measuring thrust in the market due to the difficulties associated with developing a test stand for extremely low thrust outputs. Despite the difficulties, there is an ever-growing need to develop new methods of measuring thrust as the increased demand for small satellites has prompted investors from the government and private sectors to conduct further research into the development of better propulsion systems for space applications. A part of the developmental process of making propulsion systems is being able to test the thrust of these propulsion systems under vacuum conditions that simulate a space environment. This report details the research conducted on existing test stands as well as the process of designing, manufacturing, and testing a thrust measurement device.