美國

As electronics continue to shrink in size, the cost and environmental impact of current methods of production are increasing dramatically. The purpose of this experiment was to lay the groundwork in another potential method of creating nanowires and printed circuit boards. We believe that through the exposure of supercritical CO2, metalized electrospun fibers with gold nanoparticles will have increased conductivity. In addition, the adhesion of metal to polymer thin films can be controlled with a poly (ethylene oxide) (PEO) mask on both silicon and Kapton substrates. This study found that a specific concentration of gold nanoparticles can make a solution of poly (methyl methacrylate) (PMMA) in chloroform that cannot be electrospun, spinnable. Scanning electron microscopy also confirmed that scCO2 smoothes the surface of the fibers and makes them more uniform. EDX analysis also found that exposure to scCO2 also removed all residues of solvent and cross.sectional transmission electron microscopy showed that the nanoparticles were conglomerated near the surface. In conclusion, scCO2 and gold nanoparticles respectively enhanced the morphology of the fibers and made the electrospinning process more robust. Cross.sectional analysis also showed that the nanoparticles attracted the deposited gold into the fiber making prongs reach from the deposition into the fiber, but there was no test to quantify the adbesion. Using the spray bottle test, the gold still remained on wires. The resistivity of the micro wires was extremely close to that of gold creating resistances within hundreds of ohms over hundreds of micrometers of wires. Thin Films masked with PEO were exposed to scCO2 and metalized with gold or copper. Atomic force microscopy analysis shows unique crystallization formations of poly (capro lactone) (PCL) after scCO2 exposure. ASTM standard peel tests determined that the process was successful with PCL thin films. On the Kapton samples, peeling patterns reversed when the thickness became too great to melt in scCO2.+ Through perfecting these processes, the electronics industry can continue in its miniaturization while the environmental and monetary costs.

「風笛」是台灣原住民鄒族的信號用具及祈雨法器，由一條繩子綁一支竹片構成。轉動風笛時，竹片會繞繩子自轉並拍打空氣而發出聲音，並有上下飛舞的現象。 \r 風笛產生聲音的原因，為竹片拍打空氣而造成的渦流共振現象；又由於繩子扭力大小及方向改變，使風笛的音調忽高忽低、響度忽大忽小、且竹片會在兩個平面上公轉，而有週期性變化。 \r 施力使風笛公轉轉速加快時，竹片自轉速率也變快，使其音調愈高、響度愈大；而繩愈短、愈粗時，竹片的公轉週期將愈短。

Skin cancer, including basal cell and squamous cell skin carcinoma, is known to\r be the most common cancer type. Skin cancer is thought to make up half of all known\r cancers. Over one million non-melanoma skin cancers (NMSC) are reported every year. \r Approximately 300,000 of these cases are squamous cell carcinoma (SCC). It is\r estimated that about 2,000 people die from NMSC each year. Of the two skin cancer\r types, SCC tends to be the more clinically aggressive and likely to spread and invade,\r typically by way of blood or lymphatic vessels. Understanding the signaling pathways\r in SCC cells that regulate invasion will be important for developing improved cancer\r treatments. The signal transducer and activator of transcription 3 (Stat3) protein is a\r central regulator of numerous cellular activities, including proliferation, survival, and\r motility. Stat3 also has enhanced activity in many cancers, including skin SCC. This\r study shows that Stat3 regulates several invasive properties in a human skin SCC cell culture model.\r HGF (hepatocyte growth factor)- induced cell schattering was assessed for\r SRB12-p9 cells (p9WT), a human skin SCC cell line, along with SRB12-p9 cells\r engineered to have reduced Stat3 activity. Next, a cell viability-based adhesion assay\r was performed with these cells. Finally, severe combined immunodeficient (SCID)\r mice were injected subcutaneously with P9WT and S3DN cells and tumors were\r measured twice weekly. Extracted tumors were analyzed by immunohistochemistry and Western blotting for expression of the invasion related enzyme, MMP-2 and MMP-9.\r The suppression of Stat3 activity in S3DN cell lines resulted in reduced motility,\r greater adhesion, and a less invasive phenotype in SCID mice. Immunohistochemistry and Western blotting indicated higher levels of MMPs in the P9WT cells with\r expression localization towards the outer perimeter of the tumors. This data suggests\r that Stat3 plays a role in skin SCC invasion and better understanding of Stat3 function\r could lead to improved treatment and prevention of the disease.

The pharmaceutical industry is constantly searching for methods that allow drugs to be delivered as a direct response to a specific stimulus, in which the locus of delivery is in the vicinity of required region. A unique thermo?reversible hydrogel,F127 modified with dimethacrylate (DMA), that can deliver drugs at physiological temperatures was synthesized. Nanoparticles which are specific for targeting human body cancer cell were absorbed by this hydrogel. The toxicity of nanoparticles with different diameters and coating was measured using the MTT assay. It was found that nanoparticles with smaller diameters and folate coating were most toxic to the cancer cells. The release rate of the nanoparticles from the hydrogel was measured as a function of temperature with the hydrogel releasing approximately 3 L nanoparticles per hour. Exposing this drug delivery system to cancer cells would effectively inhibit MCF7 cell proliferation. By grafting this nanoparticle?loaded hydrogel onto a thermoelectric module, the release of the drug would be controlled. Thus, a successful temperature sensitive hydrogel was synthesized that releases cancer?targeting nanoparticles which inhibit cancer cell proliferation, thereby engineering a controlled drug delivery system.

This research introduces a new, more efficient method of age determination for eclipsing Binary through use of celestial Positioning . Statistical Analysis of x-y plots of eclipsing Binary Stars within our, Milky Way Galaxy were conducted in order to find the standard deviation of each eclipsing binary star’s distance from the celestial equator. Before the standard deviations could be considered for comparison, the medians from each of the three s-y plots were examined. There medians had to show a value close to zero in order for the standard deviations to be relevant. A value close to zero indicates a proportional and symmetrical plot with an equal distribution of stars on each side of the plot. All three plots generated indicted a median no greater than 1/100 in distance from the celestial equator. A low standard deviation indicates young relative age. The statictical analysis calculated standard deviations of 2.41 for W Ursae Majoris, 1.77 for Algol, and 1.20 for Deta Lyrae. The statistical analyses were then compared to the previously made visual and mathematical analyses conducted in previous years’ studies. All analyses conducted conclude that W Ursae Majoris is the oldest type and Beta Lyrae is the youngest type of eclipsing binary star. This method can be implemented to greatly reduce time in studying the relative ages of individual objects and types of objects within our Milky Way Galaxy.

In the last two decades, there has been increased interest in the utility of quantum scale semiconductors. These fluorescent single crystals can be as small as 1 nm in diameter, and their size and shape has been shown to be controlled by the duration, temperature, and ligand molecules used in their synthesis. Quantum dots, provide clear benefits over the organic dyes currently used for tracking biological processes. Yet, as the production of quantum dots is often very costly, the search continues for finding an industry-ready synthesis for a quantum scale semiconductor which would have high yield, optimal durability, high luminescence, and a broad absorbance range. Silicon, in particular, has been of great interest as it is the second most abundant element on the Earth’s crust and is generally a bioinert and electrochemically stable element. We report the synthesis of water-soluble, luminescent silicon nanoparticles with potential applications to bioimaging. Through a solution state top-down approach, the synthesis of hydrogen capped silicon nanoparticles was achieved in various organic solvents. The surface of the nanoparticles was capped with the functional organic molecules rendering the Si-QDs both air and water stable. Cell studies performed with our silicon nanoparticles and human monocytes show the direct applications these particles could have for tracking biological processes and the progression of cancer in the human body. In attempt to shift the luminescence of these particles, alterations of experimental methodology was also explored in the areas of reaction solvent and heating time. Through these changes, shape control of silicon nanoparticles was achieved in the form of silicon nanorods. The synthesis of this new shape of silicon at the quantum scale was confirmed by ultraviolet spectroscopy, photoluminescence, and transmission electron microscopy. The results of this study indicate that the use of silicon nanocrystals for biomedical applications is feasible.

Smoothened (SMO) is a critical component of Hedgehog (HH) pathway that is essential for stem cell renewal and is dysregulated in many cancer types. SMO is a seven transmembrane domain protein with three intracellular loops. Primary structures of SMO intracellular loops are unique and very much conserved among the species, which is indicative of significant and unique roles in intermolecular or intramolecular interactions. The hypothesis was that synthetic analogs of SMO intracellular loops may function as HH pathway inhibitors. Derivatives of second intracellular loop were synthesized utilizing automated solid phase peptide synthesis based on Fmoc chemistry. Peptides were purified by HPLC and there anti-proliferative activity tested on melanoma cells by MTT assay. Targeted libraries of second loop derivatives of varying length helped to identify compounds that inhibited the growth of melanoma cells in vitro with IC50 in nanomolar range. The most potent of antagonists obtained is the palmitoyl derivative of the Nterminal half of the loop, and is 12 residues long. Lipidation proved to be critical for the activity. Remarkably, retro-inverso versions of the peptide, in which all amino acids are in D-configuration, are even more potent and have IC50 in subnanomolar range. Circular dichroism studies proved that the peptides are folded both in aqueous solutions and in the presence of lipids mimicking the membrane environment. They also suggested that retroinverso analogs have a different fold, which may contribute to higher activity. The new compounds are promising drug candidates and present convenient tools for solving the\r mechanisms of hedgehog signaling.

In the fast-paced environment of a hospital intensive care unit (ICU), good doctor-patient communication is essential. However, medical conditions and devices often inhibit a patient’s ability to speak, write or type. Current assistive communication devices are either prohibitively expensive or cumbersome and time-consuming, creating a gap in communication during a patient’s first days in the ICU. This project applies computer vision to develop a low-cost software solution that bridges this gap by enabling patients to generate words with eye movements. In the system, a webcam acquires an image of the patient, and an image processing algorithm classifies patient’s gaze as pointing in one of eight directions. Each direction corresponds to an option on a graphical menu presented to the patient on the computer’s display. The patient can use the menu to select a preformed phrase from a list of common phrases. Patients desiring to express more complex ideas can type custom words using the menu as an ambiguous keyboard (similar to a phone keypad). In either case, the patient-generated text will be displayed on screen and read aloud through the computer’s audio system. The only hardware requirements are an existing computer and a $6 webcam. The program can process and respond to an image in 148ms. A new user can be trained in approximately 10 minutes, and after training can type a simple phrase such as “hello world” in 40 seconds. While further testing and improvement is required before the system will be ready for implementation, the project shows promise as a low-cost solution to ICU communication.