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Fibres are of great importance to various applications in human's work and lifetime. Electrospinning is a facile and versatile technique to produce ultrafine fibres that range from macro to nano scales. Hierarchical porous structures could increase interactive interfaces between ultrafine fibres and their environments. However, the gaps between by controlling fibre morphology and elevating surface area have not been filled yet. In this project, a poly(L-lactic acid) (PLLA) hierarchical porous fibrous membrane was designed and developed via an electrospinning and post-treatment strategy. The vapour induced phase separation and solvent induced re-crystallization mechanisms were proposed to explain the generation of porous nano fibres with ultra-high surface area and good interconnectivity based the comprehensive characterizations. Ultrafine particulate aerosols less than 100 nm diffuse randomly in the air and are hazardous to the environment and human health. However, these small particulate matters are difficult to remove from the air. Due to the elevated specific surface area and highly porous surface morphology, hierarchical porous PLLA fibrous membrane is more possible to capture and intercept fine aerosol particles. Thus, hierarchical porous fibrous membrane was applied as an ultrafine particulate aerosols filter. The filtration performance and pressure drop of the membrane were characterized and its quality factor was calculated. Pure PLLA porous fibres still face the disadvantages including relatively brittle mechanical and hydrophobic properties. Silk fibroin was used to coating on the surface of porous PLLA fibres successfully. Good cell morphology was observed via a multiphoton laser confocal microscope on electrospun PLLA/SF fibrous membranes. The membrane then rolled up towards vascular scaffolds.

Cellular analysis is a vital part of diagnostics testing for most diseases. The development of modern technologies has led to great advancement in this task. However, the use of cellular analysis systems is limited mainly to laboratories and clinics due to their high cost and large size. Providing affordable and accessible diagnostic testing to the majority of population in the developing world and resources-limited regions remains a technical challenge. To overcome this challenge, cost-effective and portable point-of-care (POC) systems have emerged in recent years as a priming approach. This thesis focuses on the development of such POC systems for the purpose of cellular analysis. These systems include sub-pixel resolution holographic imager for cellular profiling and microfluidic platforms for sorting cell populations in clinical samples and capturing single cells. First, a new lens-free holographic system is reported as a portable imaging tool for fast screening and profiling of individual cells. Compared to conventional microscopy, this system is cheaper in cost, and portable; it can provide fast automatic detection over a large field-of-view and profile cells for in terms of their molecular properties. To enhance the resolution of the lens-free holographic system, a novel sub-pixel resolution enhancement method has been developed. Typical lens-free holographic systems are limited in resolution by the pixel size of their inherent image sensors. The developed method can overcome this limitation by applying compressive sensing strategy to the reconstruction process. Compared to other resolution enhancement methods for lens-free holography, this method does not require additional hardware or multiple exposures in measurement, thus provides the potential for fast imaging of sub-pixel targets. It can also be further applied to other nonlinear holographic imaging systems. In addition to cell imaging, novel microfluidic platforms were also developed to address the challenges in separating and capturing scant cells in blood or other fluid samples from patients. A single-cell capturing system is developed for the detection of lymphoma from cerebral spinal fluid (CSF) samples. Compared to existing single-cell capturing systems, this chip offers the advantage of antibody-free trapping mechanism, large number of sites for high throughput screening, and special geometry that size-selectively captures lymphoid cells. Blood sample usually contains a variety of cell populations which makes it difficult to sort low abundant cell for clinical diagnosis. To achieve high efficiency separation of cell populations in blood stream, a hybrid magnetic-microfluidic cell sorting system was developed. Compared with previous work, the new system achieved higher separation efficiency without damaging target cells; it is also easier to assemble and thus eliminates additional training needed for device operation. These POC systems provide versatile approach for fast, cheap and accurate disease diagnosis. With further customization specific to the diseases and more clinical testing, they can be applied as powerful tools for more accessible healthcare in low-income and resources limited regions.

This thesis consists of three studies that investigate how important political relations are in finance. In the first study, I find that poor bilateral political relations between the US and other countries negatively influence US media dissemination toward non-US firms with American Depositary Receipts (ADRs). I also show that US media negativity has downward pressure on ADR firms’ home market prices and such negative impact is reduced during the year when political relations are poor—an indication that investors react to real media bias. I conclude the first study by showing that negative US media coverage leads to a higher likelihood of ADR firms terminating their ADRs. The second study finds strong empirical evidence showing that when bilateral political relations between a country and the US are poor, the level of US institutional ownership and the number of institutional investors are low for American Depositary Receipt (ADR) firms from that country. In addition, the second study discusses whether a country’s popularity among Americans and an international crisis influence the level of US institutional ownership. Furthermore, following the previous literature, I show empirically that a high level of US institutional ownership promotes better corporate governance; to do so, I look at firm value, class action lawsuits and voluntary disclosure news. The third study considers whether bilateral political relations affect the board structure of S&P 1500 companies—specifically the proportion of foreign independent directors (FIDs). I find strong empirical evidence that when bilateral political relations between a country and the US are poor, the proportion of FIDs from that country hired by US firms is small. The threat of a firm losing technology and insider information to countries with poor political relations are considered costs by US firms, so when firms do hire FIDs from countries that have poor political relations with the US, I empirically show that the benefits are greater than the costs. I conclude the third study with an M&A analysis, which finds that firms have a high proportion of FIDs from countries where their acquisition targets exist and bilateral political relations do not influence such a proportion.

Glutamatergic system adaptive remodeling has newly been identified as an important neural substrate of drug dependence. As extensively used anticonvulsant and hypnotic drugs, benzodiazepines act primarily as allosteric modulators of GABAA receptors; while the withdrawal symptoms are associated with enhanced AMPAR function. To investigate AMPAR remodeling during benzodiazepine withdrawal, whole-cell recordings were conducted in rat hippocampal CA1 neurons. The amplitude of AMPAR-mediated currents was enhanced 30-50% after 2-day FZP withdrawal, without changes in channel kinetic properties. Agonist-elicited AMPA currents were significantly blocked by spermine, suggesting augmented membrane incorporation of GluR2-lacking AMPARs. As GluR1-containing AMPARs are centrally involved in neuronal plasticity, we sought to determine whether changes in GluR1 subunit expression and distribution occurred during benzodiazepine withdrawal. Confocal imaging analysis revealed that FZP withdrawal promoted GluR1 subunit membrane incorporation, in the absence of GluR2 subunit alterations. Immunoblotting assays showed that GluR1, but not GluR2, subunit protein levels were enhanced in all subcellular fractions from CA1 minislices. As with LTP, FZP-withdrawal-induced GluR1 incorporation into membrane/synapse may require the GluR1-trafficking protein SAP97 and AMPAR phosphorylation by PKA may be mediated via a SAP97-AKAP interaction. Therefore, the expression and membrane/synapse redistribution of these proteins were investigated using subcellular fractionation and immunoblotting techniques. Consistent with increases in SAP97 immunoreactivity, protein levels of phospho-Ser845 GluR1 and AKAP79/150 were concomitantly elevated in membrane/synapse-associated compartments from FZP-withdrawn rats. There were no alterations in the immunoreactivity of PKA regulatory and catalytic subunits. These findings indicate that increased interaction between SAP97-AKAP-PKA, rather than enhanced PKA expression, resulted in increases in phosphorylated AMPARs and thus may be involved in AMPAR potentiation. The molecular mechanisms underlying benzodiazepine withdrawal were further explored by microarray analysis and Ingenuity Pathway Analysis. Twenty-seven known gene transcripts were differentially expressed during FZP withdrawal, including 19 significantly upregulated and 8 downregulated transcripts. Based on the transcripts identified, one network and two biological (LTP-associated and neurotransmission) pathways were constructed by IPA, illustrating the interactions among these genes products. Collectively, our findings provide evidence that during FZP withdrawal, increased expression and phosphorylation of GluR1-containing AMPARs and associated upregulation of AMPAR function in hippocampal CA1 pyramidal neurons share fundamental similarities with the mechanisms underlying activity-dependent synaptic plasticity.

Effects of textile processing on breaking strength, breaking elongation, morphological properties and dimensional properties were investigated and analyzed. Cotton varieties were processed under various ginning and carding conditions into a T-shirts. The produced T-shirts were washed and dried repeatedly. Fibers were collected at various processing stages and tested by a Mantis® single fiber tensile tester. The breaking strength and breaking elongation of cotton fibers were reduced substantially due to textile processing. A higher ginning rate generated a higher average breaking strength and a lower breaking elongation compared to that from a lower ginning rate. A higher carding rate adversely affected the tensile properties for entire range of the processes. Using of 2 lint cleaners at the gin resulted in a lower tensile properties than that of 1 lint cleaner. Although the results were not statistically significant, use of 2 lint cleaners at gin resulted in a lower average length shrinkage in T-shirts and more damage to the fiber surface after repeated washing/drying. The progressive length shrinkage of the T-shirts during 32 washing/drying cycles was shown to be consistently higher for the higher ginning and carding rates. The progressive width and area shrinkage on the other hand did not show the effects of processing clearly. A limited microscopic study suggests that the number of lint cleaners in ginning may be the most significant contributor to fiber damage as shown by the broken fibrils and cracks on fiber surfaces.

Although there has been increased research on wandering over the years, little is known about why some people with dementia have a tendency to constantly ambulate while others do not. It has been suggested, however, that such variance observed in wandering could be a function of continuity of an individual's premorbid personality and ways to manage stress. Therefore, being guided by the Continuity Theory and the Need-Driven Dementia-Compromised Behavior model, this study aimed to explore relationships of premorbid personality and behavioral responses to stress to wandering behavior of residents with dementia in long term care facilities. Using a random cluster sampling method, 70 ambulatory residents with dementia were selected from 13 nursing homes and 3 assisted living facilities. Subjects' degree of cognitive impairment was examined using the Mini-Mental State Exam (MMSE); premorbid personality and stress responses were assessed by the NEO-Five Factor Personality Inventory and the Behavioral Responses to Stress Scale; and wandering behavior was measured using the Revised Algase Wandering Scale - Nursing Home Version (RAWS-NH), which consists of six subscales including persistent walking (PW), specific patterns (SP), spatial disorientation (SD), eloping behavior (EB), and negative outcomes (NO). The MMSE scores were significantly negatively correlated with RAWS overall and all of the six subscale scores. Significant negative correlations were found between the extraversion personality and the two wandering subscales of SD and EB. None of the three domains of premorbid responses to stress was significantly correlated with RAWS overall and its subscales. When MMSE was controlled, extraversion appeared to be the strongest premorbid predictor for wandering overall and SD, EB, and AS, while premorbid aggression response to stress was the strongest predictor of PW. The present study joins a small but growing literature suggesting that wandering in persons with dementia may be an adaptive behavior which reflects continuity of premorbid personality and lifelong patterns of coping with stress. Understanding wandering behavior in the light of the demented individuals' current as well as past characteristics would enable health care professionals to plan and provide more effective individualized care for their clients.