LASER INDUCED LOCAL STRUCTURAL AND PROPERTY MODIFICATIONS IN SEMICONDUCTORS FOR ELECTRONIC AND PHOTONIC SUPERSTRUCTURES SIC TO GRAPHENE CONVERSION

Graphene is a single atomic layer two-dimensional (2D) hexagonal crystal of carbon atoms with sp2-bonding. Because of its various special or unique properties, graphene has attracted huge attention and considerable interest in recent years. This PhD research work focuses on the development of a novel approach to fabricating graphene micro- and nano-structures using a 532 nm Nd:YAG laser, a technique based on local conversion of 3C-SiC thin film into graphene. Different from other reported laser- induced graphene on single crystalline 4H- or 6H- SiC, this study focus on 3C-SiC polycrystal film grown using MBE. Because the SiC thin film is grown on silicon wafer, this approach may potentially lead to various new technologies that are compatible with those of Si microelectronics for fabricating graphene-based electronic, optoelectronic, and photonic devices. The growth conditions for depositing 3C-SiC using MBE on Si wafers with three orientations, (100), (110), and (111), were evaluated and explored. The surface morphology and crystalline structure of 3C-SiC epilayer were investigated with SEM, AFM, XRD, µ-Raman, and TEM. The laser modification process to convert 3C-SiC into graphene layers has been developed and optimized by studying the quality dependence of the graphene layers on incident power, irradiation time, and surface morphology of the SiC film. The laser and power density used in this study which focused on thin film SiC was compared with those used in other related research works which focused on bulk SiC. The laser-induced graphene was characterized with µ-Raman, SEM/EDS, TEM, AFM, and, I-V curve tracer. Selective deposition of 3C-SiC thin film on patterned Si substrate with SiO2 as deposition mask has been demonstrated, which may allow the realization of graphene nanostructures (e.g., dots and ribbons) smaller than the diffraction limit spot size of the laser beam, down to the order of 100 nm. The electrical conductance of directly written graphene micro-ribbon (< 1 µm) was measured via overlaying two micro- electrodes using e-beam lithography and e-beam evaporation. The crystalline quality (stacking order, defect or disorder, strain, crystallite size, etc.) of laser-induced graphene was analyzed using Raman spectroscopy through the comparison with pristine natural graphite and CVD-grown monolayer graphene on SiO2/Si and other substrates. The experimental results reveal the feasibility of laser modification techniques as an efficient, inexpensive, and versatile (any shape and location) means in local synthesis of graphene, especially in patterning graphene nanostructures. Different from other laser induced graphene research works, which were concentrated on bulk SiC wafers, this PhD research work focuses on thin film SiC grown on Si (111) for the first time

CALIBRATING SLOPE-DEPENDENT ERRORS IN PROFILOMETRY

Optical profilometers, such as scanning white light interferometers and confocal microscopes, provide high resolution measurements and are widely utilized in many fields for measuring surface topography. The techniques are capable of high-speed surface measurements with nanometer-scale repeatability, and are used in industries such as data storage, automotive, MEMS, electronics, micro-optics, and bio-medical, to name a few. The instrument works best on flat, stepped structures, and slope-dependent systematic errors can be present in the measurement of steep sloped regions. These errors can be the same order of magnitude as features on the surface to be measured. Researchers have carried out many studies of these errors from first principle analyses; however the errors depend on proprietary details of the optical design and cannot be exactly calculated from first principles. The problem is further complicated by a lack of calibration artifacts to measure the errors directly. We propose a self-calibration technique, the random ball test, for calibrating slope-dependent errors of such instruments. A simulation study validates the approach and shows that the random ball test is effective in practical limits. We demonstrate the calibration on a 50x confocal microscope and a 50x white light interferometer with a specific chosen algorithm, find a surface slope- dependent bias that increases monotonically with the magnitude of the surface slope. The uncertainty of the calibration is smaller than the observed measurement bias and is dominated by residual random noise. Effects such as distortion, drift and ball radius uncertainty were investigated to understand their contribution to the calibration uncertainty

Children’s expressions of gratitude and their relations with parental values and parenting: insights from China and the United States

Gratitude, referring to a dispositional trait to appropriately show gratefulness to a benefactor for a gift or help received (Tudge, Freitas, & O’Brien, 2015), has been viewed as a moral virtue by philosophers and psychologists (e.g., Carr, Morgan, & Gulliford, 2015; McConnell, 1993, 2016). According to Tudge and colleagues, gratitude, as a moral virtue occurs when the beneficiary recognizes that a benefit is freely and intentionally provided by a benefactor, and the beneficiary autonomously repay the benefactor with something that the benefactor wants or needs if an opportunity presents itself. Gratitude, like any virtue, is not innate. Possessing virtuous gratitude requires one to understand the motivation and intentionality behind the benefits, knowing what might be the appropriate responses in a given situation, and to be able to think and act autonomously (Morgan & Gulliford, 2018; Tudge, Freitas, & O’Brien, 2015). To acquire these sociocognitive abilities and experiences, actively engaging in increasingly complex and relevant practices is necessary. Through these practices, one also gradually internalizes standards that are morally required and highly valued by the cultural group to which he/she belongs. Therefore, the development of virtuous gratitude is driven by the synergistic effects of different factors, such as sociocognitive abilities, cultural values, and everyday interactions between parents and children. The purpose of the present study is to have a better understanding of children’s expressions of gratitude and their relations with parental values and parenting in China and the United States. First, the present research investigated the expression of gratitude among 520 Chinese youth (M = 10.60 years, SD = 2.09; 56.0% female) and 489 North American youth (M = 10.28 years, SD = 2.11; 53.8% female). Consistent with what I had expected, Chinese children were less likely to express concrete gratitude, and more likely to express connective gratitude than were the North American children. Additionally, different age-related patterns of expressions of verbal, concrete, and connective gratitude were found. Across societies, older children were more likely to express connective gratitude and less likely to express concrete gratitude than were their younger counterparts. Beyond that, I examined the association between parental values for their children and children’s expressions of gratitude. However, results did not support the hypothesis that parents’ values of autonomy and relatedness would be associated with children’s expressions of connective gratitude. Findings indicated that parental values and gratitude expression were related in different ways in the Chinese and the U.S. sample. Parental values of separateness negatively predicted expression of concrete gratitude among Chinese participants, whereas in the U.S. sample, separated values were negatively associated with connective gratitude. Furthermore, by interviewing 29 North American and 19 Chinese families, I identified strategies that parents used to promote gratitude in China and the United States. In line with what had been predicted, results indicated that both the Chinese and the U.S. parents used various kinds of strategies, including role modeling, discussion about gratitude, and reinforcing gratitude expression behaviors. Moreover, Chinese parents emphasized the importance of expressing gratitude to family and relatives and regarded expressing gratefulness to family members as an effective strategy to foster gratitude in children. Additionally, I explored the relation between children’s expressions of gratitude and their wishes. Consistent with the hypothesis, findings of the present study suggested that children’s social-oriented wishes were significantly associated with connective gratitude for both the Chinese and the U.S. children. Finally, a positive relation between connective gratitude and preferences to give to charity has been found among Chinese children. However, no significant relations between gratitude and spending preferences were found among the North American youth. Findings of the present study provide important educational implications for educators and practitioners aiming to develop effective intervention programs for character development. This study also greatly advances the understanding of the ways in which culture influences the development of virtuous gratitude

Ancient gene transfer from algae to animals: Mechanisms and evolutionary significance

Background Horizontal gene transfer (HGT) is traditionally considered to be rare in multicellular eukaryotes such as animals. Recently, many genes of miscellaneous algal origins were discovered in choanoflagellates. Considering that choanoflagellates are the existing closest relatives of animals, we speculated that ancient HGT might have occurred in the unicellular ancestor of animals and affected the long-term evolution of animals. Results Through genome screening, phylogenetic and domain analyses, we identified 14 gene families, including 92 genes, in the tunicate Ciona intestinalis that are likely derived from miscellaneous photosynthetic eukaryotes. Almost all of these gene families are distributed in diverse animals, suggesting that they were mostly acquired by the common ancestor of animals. Their miscellaneous origins also suggest that these genes are not derived from a particular algal endosymbiont. In addition, most genes identified in our analyses are functionally related to molecule transport, cellular regulation and methylation signaling, suggesting that the acquisition of these genes might have facilitated the intercellular communication in the ancestral animal. Conclusions Our findings provide additional evidence that algal genes in aplastidic eukaryotes are not exclusively derived from historical plastids and thus important for interpreting the evolution of eukaryotic photosynthesis. Most importantly, our data represent the first evidence that more anciently acquired genes might exist in animals and that ancient HGT events have played an important role in animal evolution

A study of Chinese composer Huang Anlun and his Chinese Rhapsody No. 3

The purpose of this project was twofold because it filled a need in two areas. First, the Chinese Rhapsody No. 3 is a work studied by all Chinese saxophonists, yet to date, no professional-level recording of the work is available. My recording fills this void. Second, both the Chinese Rhapsody No. 3 and its composer are unknown to Western saxophonists. The document will introduce Huang Anlun and his Chinese Rhapsody No. 3 through a brief biography and an interpretive analysis of the Rhapsody through various aspects, such as Chinese traditional music style and the imitation of Chinese traditional instrument timbres. This will enable more people to know about one of China’s excellent composers and an aspect of China’s unique traditional culture

Association of the TLR4 Asp299Gly polymorphism with lung function in relation to body mass index

<p>Abstract</p> <p>Background</p> <p>Previous studies have shown conflicting results for the association between TLR4 polymorphism (Asp299Gly) and lung function. We investigated the influence of TLR4 Asp299Gly, a polymorphism, on lung function in a community population.</p> <p>Methods</p> <p>In 2003, a cross-sectional survey was conducted to assess the respiratory health of residents living in and around the town of Humboldt, Saskatchewan, Canada. There were 2090 adults age 18-79 years who completed a questionnaire that included a medical and smoking history, as well as socio-economic and lifestyle variables. Genetic information and lung function test measurements were available on 1725 subjects (754 males and 971 females) of the 2090 respondents. These subjects were selected for further analysis to investigate the association between TLR4 Asp299Gly genotype and forced expiratory volume in the first second in liters (FEV₁), forced vital capacity in liters (FVC), FEV₁/FVC ratio, and forced expiratory flow rate in liters/second (FEF_25-75). Multivariable linear regression analysis was used to investigate associations.</p> <p>Results</p> <p><b>A</b>djusted mean values of FEV₁and FVC were significantly different between TLR4 wild type and TLR4 variant groups [Mean ± S.E.: (TLR4 wild type - FEV₁: 3.18 ± 0.02, FVC: 3.95 ± 0.03; TLR4 variant - FEV₁: 3.31 ± 0.06, FVC: 4.14 ± 0.07)]. Based on multivariable regression analysis, we observed that body mass index (BMI) was associated with decreased FEV₁/FVC ratio and FEF_25-75in TLR4 variant group but not in wild type group.</p> <p>Conclusion</p> <p>BMI may modify the associations of TLR4 Asp299Gly polymorphism with FEV₁/FVC ratio and FEF_25-75.</p

Is Intracranial Atherosclerosis an Independent Risk Factor for Cerebral Atrophy? A Retrospective Evaluation

<p>Abstract</p> <p>Background</p> <p>Our purpose was to study the association between the intracranial atherosclerosis as measured by cavernous carotid artery calcification (ICAC) observed on head CT and atrophic changes of supra-tentorial brain demonstrated by MRI.</p> <p>Methods</p> <p>Institutional review board approval was obtained for this retrospective study incorporating 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the intracranial cavernous carotids (ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These 4 groups were then combined into high (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify cortical and central atrophy. Demographics and cardiovascular risk factors were evaluated in subjects with high and low ICAC. Relationship between CT demonstrated ICAC and brain atrophy patterns were evaluated both without and with adjustment for cerebral ischemic scores and cardiovascular risk factors.</p> <p>Results</p> <p>Forty-six of the 65 (71%) patients had high ICAC on head CT. Subjects with high ICAC were older, and had higher prevalence of hypertension, diabetes, coronary artery disease (CAD), atrial fibrillation and history of previous stroke (CVA) compared to those with low ICAC. Age demonstrated strong correlation with both supratentorial atrophy patterns. There was no correlation between ICAC and cortical atrophy. There was correlation however between central atrophy and ICAC. This persisted even after adjustment for age.</p> <p>Conclusion</p> <p>Age is the most important determinant of atrophic cerebral changes. However, high ICAC demonstrated age independent association with central atrophy.</p

Paired Associative Stimulation of the Auditory System: A Proof-Of-Principle Study

Background Paired associative stimulation (PAS) consisting of repeated application of transcranial magnetic stimulation (TMS) pulses and contingent exteroceptive stimuli has been shown to induce neuroplastic effects in the motor and somatosensory system. The objective was to investigate whether the auditory system can be modulated by PAS. Methods Acoustic stimuli (4 kHz) were paired with TMS of the auditory cortex with intervals of either 45 ms (PAS(45 ms)) or 10 ms (PAS(10 ms)). Two-hundred paired stimuli were applied at 0.1 Hz and effects were compared with low frequency repetitive TMS (rTMS) at 0.1 Hz (200 stimuli) and 1 Hz (1000 stimuli) in eleven healthy students. Auditory cortex excitability was measured before and after the interventions by long latency auditory evoked potentials (AEPs) for the tone (4 kHz) used in the pairing, and a control tone (1 kHz) in a within subjects design. Results Amplitudes of the N1-P2 complex were reduced for the 4 kHz tone after both PAS(45 ms) and PAS(10 ms), but not after the 0.1 Hz and 1 Hz rTMS protocols with more pronounced effects for PAS(45 ms). Similar, but less pronounced effects were observed for the 1 kHz control tone. Conclusion These findings indicate that paired associative stimulation may induce tonotopically specific and also tone unspecific human auditory cortex plasticity

New Insight into the Antifibrotic Effects of Praziquantel on Mice in Infection with Schistosoma japonicum

Schistosomiasis is a parasitic disease infecting more than 200 million people in the world. Although chemotherapy targeting on killing schistosomes is one of the main strategies in the disease control, there are few effective ways of dealing with liver fibrosis caused by the parasite infection in the chronic and advanced stages of schistosomiasis. For this reason, new strategies and prospective drugs, which exert antifibrotic effects, are urgently required.-induced liver fibrosis was inhibited by PZQ treatment for 30 days. Furthermore, we analyzed the effects of praziquantel on mouse primary hepatic stellate cells (HSCs). It is indicated that mRNA expressions of Col1α1, Col3α1, α-SMA, TGF-β, MMP9 and TIMP1 of HSCs were all inhibited after praziquantel anti-parasite treatments.The significant amelioration of hepatic fibrosis by praziquantel treatment validates it as a promising drug of anti-fibrosis and offers potential of a new chemotherapy for hepatic fibrosis resulting from schistosomiasis