Miracle-dz/UniFAR-FTUs huggingface dataset:
Optical and electronic interactions at the nanoscale

In this dissertation, we discuss optical and electronic interactions in three nanometer scale semiconductor systems in a broadly defined sense. These studies are performed using time-integrated and time-resolved optical spectroscopies and temperatureand field-dependent electrical transport measurements. We first discuss the construction and optimization of an optical apparatus for performing broadband, time-integrated and sub-picosecond fluorescence and absorption measurements. Using this apparatus, we then characterize the impact on the optically-excited carrier relaxation dynamics of cadmium selenide quantum dots due to a surface treatment previously shown to increase interparticle coupling, namely the solution exchange of native, aliphatic ligands for thiocyanate followed by subsequent sample annealing. We find that this ligand treatment leads to faster surface state electron trapping, a greater proportion of surface photoluminescence, and an increased rate of nonradiative decay due to enhanced interparticle coupling. In contrast to trends previously observed at room temperature, we also show that at 10 K the band-edge absorptive bleach is dominated by 1Sh hole occupation in the quantum dot interior. In the second study detailed here, we use this time-resolved photoluminescence apparatus to demonstrate an enhancement of radiative rates in cadmium sulfide nanowires due to plasmonic enhancement from interactions of hot excitons with a concentric electrically conductive silver coating. In the final experiment we return to cadmium selenide quantum dots to investigate the electronic interactions among quantum dots in high-mobility indium-doped field effect transistors at low temperature. We show that application of a gate bias to the transistor to accumulate electrons in the quantum dot channel increases the "localization product" (localization length times dielectric constant) describing transport at the Fermi level, as expected for Fermi level changes near a mobility edge. Our measurements suggest that the localization length increases to significantly greater than the quantum dot diameter and further that application of gate bias decreases the mobility gap separating localized and extended states. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Physics & Astronomy First Advisor James M. Kikkawa
A facile approach to the hydrothermal synthesis of graphene

In this work, we demonstrate a fast hydrothermal approach for the facile synthesis of graphene (GN) from reduction of graphene oxide (GO) in the presence of reducing agents (sodium hydroxide, NaOH). The obtained GN was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopic techniques (Raman) and thermogravimetric analysis (TG). It was observed that preparation periods of GN are significantly reduced in the strong alkali environment, as a result of rapid reduction reaction under the conditions of high temperature and pressure in hydrothermal reaction autoclave. Interestingly, it was also found that the obtained GN could be easily separated and purified, which could be beneficial to the mass production of GN. In addition, the characterization results showed that GN has extraordinary improvement of thermal stability. The facile synthesis method developed in this study may facilitate the potential applications of GN-based composites and devices.
Kinetics of Anti–Hepatitis B Surface Antigen Titers After Hepatitis B Vaccination in Patients With Inflammatory Bowel Disease

Background:Clinically significant hepatitis B (HB) virus infection has been documented among immunocompromised patients who do not maintain anti–hepatitis surface antigen (anti-HBs) concentrations ≥10 IU/L after an adequate response to the vaccine. The aims of the study were to understand the kinetics of anti-HBs titers over time in patients with inflammatory bowel disease (IBD) who initially responded to vaccination and to identify factors predictive of losing protective anti-HBs titers. Methods:Patients with IBD with a response (anti-HBs > 10 IU/L at 1–3 months) to HB virus vaccination were prospectively included. Anti-HBs titers were measured at 6 and 12 months. Anti-HBs titers were considered negative if they were <10 IU/L at any time during the follow-up. The kinetics of anti-HBs titers in the long term was estimated using Kaplan–Meier curves. Cox regression analysis was performed to identify the factors predictive of losing protective anti-HBs titers. Results:The sample comprised 100 patients (mean age, 42 years; 68% Crohn’s disease; 49% on thiopurines; and 14% on anti–tumor necrosis factors during follow-up). The cumulative incidence of loss of anti-HBs titers was 2% after 6 months and 15% after 12 months. The incidence rate of loss of protective anti-HBs titers was 18% per patient-year. Baseline (after vaccination) anti-HBs titers were lower among patients whose titers became negative during the follow-up than among those who maintained them >10 IU/L (191 versus 515 IU/L; P < 0.001). Treatment with anti-TNFs was the only factor associated with a higher risk of loss of anti-HBs (hazard ratio = 3.1; 95% confidence interval = 1.1–8.8; P = 0.03). Conclusions:A high proportion of patients with IBD with protective anti-HBs titers after vaccination lose them over time (18% per patient-year of follow-up). The risk of losing protective anti-HBs titers is 3-fold higher among patients on anti- tumor necrosis factors therapy.
Efficient gene transfer into nondividing cells by adeno-associated virus-based vectors

Gene transfer vectors based on adeno-associated virus (AAV) are emerging as highly promising for use in human gene therapy by virtue of their characteristics of wide host range, high transduction efficiencies, and lack of cytopathogenicity. To better define the biology of AAV-mediated gene transfer, we tested the ability of an AAV vector to efficiently introduce transgenes into nonproliferating cell populations. Cells were induced into a nonproliferative state by treatment with the DNA synthesis inhibitors fluorodeoxyuridine and aphidicolin or by contact inhibition induced by confluence and serum starvation. Cells in logarithmic growth or DNA synthesis arrest were transduced with vCWR:beta gal, an AAV-based vector encoding beta-galactosidase under Rous sarcoma virus long terminal repeat promoter control. Under each condition tested, vCWR:beta Gal expression in nondividing cells was at least equivalent to that in actively proliferating cells, suggesting that mechanisms for virus attachment, nuclear transport, virion uncoating, and perhaps some limited second-strand synthesis of AAV vectors were present in nondividing cells. Southern hybridization analysis of vector sequences from cells transduced while in DNA synthetic arrest and expanded after release of the block confirmed ultimate integration of the vector genome into cellular chromosomal DNA. These findings may provide the basis for the use of AAV-based vectors for gene transfer into quiescent cell populations such as totipotent hematopoietic stem cells.
Clinical production, stability studies and PET imaging with 16-alpha-[18F]fluoroestradiol ([18F]FES) in ER positive breast cancer patients.

PURPOSE 18F-Fluoroestradiol [18F]FES has emerged as a valuable PET tracer to predict the response to hormone therapy in recurrent or metastatic breast cancer patients. A clinically acceptable product requires a rapid reliable synthesis and must be demonstrated to maintain chemical stability and receptor specific uptake during patient studies. [18F]FES then becomes a dependable tracer for the evaluation and management of breast cancer patients. METHODS An improved automated radiosynthesis of [18F]FES was developed. Stability studies of the injectible form of [18F]FES were performed up to 24 h after dose formulation under normal storage conditions. A comparative FES/FDG PET imaging in ER+ breast cancer patients is reported. RESULTS The improved synthesis procedure utilizes fewer hydrolysis steps and a single high performance liquid column chromatography (HPLC) purification of the labeled mixture affording [18F]FES in good yield with high radiochemical purity (>99%). Stability studies with purified [18F]FES in saline/ethanol (85:15 v/v) indicated no radiolytic or chemical degradation of this radiopharmaceutical when stored for 24 h at 20-24 degrees C. Positron Emission Tomography (PET) studies with [18F]FES and [18F]FDG in estrogen receptor positive (ER+) breast cancer patients indicated that while FDG accumulation was seen in all metabolically hyperactive sites, the uptake of FES clearly delineated the ER+ tissues regions. CONCLUSIONS An improved automated synthesis of [18F]FES has been developed and the integrity of this product has been validated by long term stability studies and clinical PET imaging studies in ER+ breast cancer patients. A lack of concordance between FES and FDG uptake in a patient with metastatic breast cancer suggests specificity of the FES for tumors expressing estrogen receptors.
Mutations in the v-Rel Transactivation Domain Indicate Altered Phosphorylation and Identify a Subset of NF-κB-Regulated Cell Death Inhibitors Important for v-Rel Transforming Activity

ABSTRACT Consistent with the constitutive activation of Rel/NF-κB in human hematopoietic tumors, the v-Rel oncoprotein induces aggressive leukemia/lymphomas in animal models. v-Rel is thus a valuable tool to characterize the role of Rel/NF-κB in cancer and the mechanisms involved. Prior studies by our group identified a serine-rich domain in v-Rel that was required for biological activity. Here, we investigated the molecular basis for the transformation defect of specific serine mutants. We show that the transforming efficiency of these mutants in primary lymphoid cells is correlated with their ability to mediate κB site-dependent transactivation and with specific changes in phosphorylation profiles. Interestingly, coexpression of the death antagonists Bcl-xL and Bcl-2 significantly increased their oncogenicity, whereas other NF-κB-regulated death inhibitors showed little or no effect. The fact that a subset of apoptosis inhibitors could rescue v-Rel transactivation mutants suggests that their reduced transcriptional activity may critically affect expression of defined death antagonists essential for oncogenesis. Consistent with this hypothesis, we observed selection for high endogenous expression of Bcl-2-related death antagonists in cells transformed by weakly transforming v-Rel mutants. These results emphasize the need for Rel/NF-κB to efficiently activate expression of a subset of antiapoptotic genes from the Bcl-2 family to manifest its oncogenic phenotype.
Regional variation in the neurochemical coding of the myenteric plexus of the human colon and changes in patients with slow transit constipation

Abstract There are differences in the structure and function between regions of the colon. In patients with slow transit constipation the activity of all regions is markedly slowed. Counts of colonic neurones in slow transit constipation have been semiquantitative and led to varying results. We have applied new methods of quantification of markers in whole mounts of the colonic myenteric plexus to compare density of innervation between regions and between normal patients and those undergoing resection for severe constipation. Whole mounts of colonic myenteric plexus were made from specimens removed for cancer treatment (controls) and cases of severe constipation. All neurones were labelled by anti‐human neuronal protein antibodies. Neurones synthesizing acetyl choline were labelled for choline acetyltransferase (ChAT) and those for nitric oxide by antisera to nitric oxide synthase (NOS). Four populations of neurones were distinguished and quantified according to the two selective markers, ChAT and NOS. In the normal major populations were NOS alone (51% of ascending colon neurones and 44% of descending colon neurones) and ChAT alone (41% ascending colon, 48% descending colon). Nitric oxide synthase/ChAT and NOS‐/ChAT‐comprised only small populations. In all regions in severe constipation, the percentage of NOS‐only colonic myenteric neurones was raised (54% ascending colon, 49% descending colon) and ChAT only was reduced (36% ascending colon, 42% descending colon). The other populations were not changed. Accurate quantification of neuronal populations in whole mounts of human colon reveals inter‐regional differences in innervation and marked changes in innervation in cases of very severe constipation.
Is the brush border membrane of the intestinal mucosa a generator of "chymosomes"?

1. The microvilli of enterocytes in calf intestine demonstrate high levels of vesiculation activity at the top and at the basal region. 2. The morphology of the vesicles associated with microvilli (100-500 nm diameter, unilamellar, few intramembraneous particles, high AP activity) is very similar to the morphology of vesicles found in the chyme. 3. Vesicles can be purified 6-10 fold from chyme of the calf intestine applying a Mg(++)-precipitation method, used for brush border membrane preparation. 4. Specific activities of alkaline phosphatase and disaccharidases were found to be much higher in chyme vesicles than in the mucosa. 5. Phospholipid content and phospholipid composition is in chyme vesicles different from brush border membrane vesicles. 6. The characterized chyme vesicles are referred to as chymosomes. We consider the mucosa as a large-scale generator of chymosomes, i.e. digestive enzymes bearing vesicles.
The hemocytes of a scorpion Palamnaeus swammerdami

Some of the cytological characteristics of the hemocytes of the scorpion, Palamnaeus swammerdami, were studied. The morphological features of the arachnid hemocytes were observed to be similar to those of hemocytes of insects, millipedes and isopods. Jones' system of hemocyte classification was extended to the arachnid hemocytes. The six classes of hemocytes indentified in the scorpion correspond to prohemocytes, plasmatocytes, granular hemoocytes, cystocytes, spherule cells and adipohemocytes of insects. A cell type comparable to oenocytoids of insects and crustaceans is absent. The prohemocytes can be subdivided into four categories that probably represent the precursors of the major cell types. The cytological characteristics of the major cell classes and the occurrence of the miniatures of some of these major cell types support the concept of Jones (62) that these cell types might have different cell lineages and might not be capable of transforming into one another. Some of the prohemocytes, plasmatocytes and granular hemocytes were amoeboid. The nature of the granules and the vacuoles of plasmatocytes and granular hemocytes were compared with the granules and vacuoles of corresponding hemocytes of other arthropods. Cystocytes did not bring about any visible coagulation similar to their counterparts in millipedes and crustaceans. Plasmatocytes, granular hemocytes and spherule cells were observed to occur in conglomerates. The cell types noted in the present study were compared with the hemocytes of other arachnids.
Lactic acid release by intra‐arterial adrenaline infusions before and after dibenyline, and its relationship to blood‐flow changes in the human forearm

Duff & Swan (1951) have shown that, in man, the continuous intraarterial infusion of a relatively large dose of adrenaline causes an initial transient increase, followed by a sustained decrease in muscle blood flow. Following the intra-arterial administration of dibenyline the constrictor response to intra-arterial adrenaline is converted into a marked and sustained dilatation persisting throughout the duration of the infusion (Allwood & Ginsburg, 1959; de la Lande & Whelan, 1959). Dilatation in response to adrenaline has been attributed by Lundholm (1956) to the release of lactic acid from muscle consequent upon the glycolytic action of adrenaline; but, though Barcroft & Cobbold (1956) found an increase in venous blood lactate with intravenous infusions of adrenaline in man, Hildes, Purser & Sherlock (1949) had not been able to show such an increase following intra-arterial adrenaline infusions. An increase in forearm blood flow with intra-arterial adrenaline following adrenergic blocking agents was seen by de la Lande & Whelan (1959), and they suggested that adrenaline may release a substance from muscle, which might be lactic acid, which is responsible for the vasodilatation. The present experiments were carried out to ascertain if intra-arterial adrenaline liberated lactic acid, and, if so, whether the response was affected by a prior infusion of dibenyline, and its relationship to the changes in forearm blood flow.
Global Asymptotic Behavior of the Chemostat: General Response Functions and Different Removal Rates

In this paper, we consider a competition model between n species in a chemostat that incorporates both monotone and nonmonotone general response functions and distinct removal rates. We show that only the species with the lowest break-even concentration survives, provided that the variation of distinct removal rates relative to the flow rate of the chemostat can be controlled by either the difference between the two lowest break-even concentrations or by a parameter based on the structure of response functions. LaSalle's extension theorem of the Lyapunov stability theory and fluctuation lemma are the main tools.
De novo esophageal neoplasia after liver transplantation

The purpose of the study was to determine the incidence, risk factors, treatment, and influence on survival of patients with de novo esophageal cancer after liver transplantation (LT). From 1988 to 2006, 1,926 patients underwent LT in our institution. A total of 9 patients (0.5%) developed a de novo esophageal cancer and 1 patient a cancer of the cardia (0.05%). A retrospective analysis was performed to reveal underlying diseases, timeframes between LT and appearance of cancer, predisposing factors, cancer therapy, complications, immunosuppressive regimens, and survival. Of our 10 patients, 7 (70%) suffered from esophageal squamous cell carcinoma (SCC) and 3 patients (30%) developed an adenocarcinoma, including the patient with cancer of the cardia. A total of 9 patients were transplanted due to alcoholic cirrhosis; 1 patient suffered from hepatocellular carcinoma in nonA‐nonB hepatitis‐related cirrhosis. Median time to tumor diagnosis was 51 months after transplantation. A total of 5 patients were treated conservatively with combined radiochemotherapy and 5 underwent surgical resection. Patients with radiochemotherapy showed a mean survival of 14.8 months vs. 24.8 months for the patients of the surgery group. No major postoperative complication has been observed. A total of 2 patients of the surgery group are still alive after a follow‐up of 15 and 89 months. In conclusion, de novo esophageal and cancer of the cardia after LT is a rare event. In spite of immunosuppression, no increased complication rate has been observed. Patients may have a survival benefit from surgical resection. Liver Transpl 13:443–450, 2007. © 2007 AASLD.
Transforming growth factor-β1 and TGF-β2 act synergistically in the fibrotic pathway in oral submucous fibrosis: An immunohistochemical observation

Abstract Background and objectives: Oral Submucous Fibrosis (OSF) is a potentially malignant oral disorder which leads to fibrosis of the oral mucosa and has a high rate of malignant transformation. The consumption of various forms of areca nut is causatively linked to the condition. The constituents of areca nut activate several pro-fibrotic cytokines, chiefly transforming growth factor-β1, β2, which leads to an increased deposition and decreased degradation of extracellular matrix and collagen. TGF-β1, β2 probably represent the major pathway in the deposition of collagen fibres in this condition. The present study aims to identify and correlate the expressions of TGF-β1 and TGF-β2 immunohistochemically on paraffin sections of various stages of OSF. A comparison was also made between normal oral mucosa and scar tissue and OSF to judge the mode, extent and type of expression of TGF β1, β2. Methods: The expression of TGF-β1 antibody (8A11, NovusBio, USA) and TGF-β2 antibody (TB21, NovusBio, USA) was detected immunohistochemically on paraffin sections of 58 and 70 cases of OSF respectively, 10 cases of normal oral mucosal tissue and 4 cases of scar tissue. A mapping of the positivity of the two cytokines was done using JenOptik camera and ProReg image analysis software. The results were statistically analysed using one way ANOVA and students "t" test. Results: Expression of TGF-β1 and TGF-β2 was more in OSF as compared with normal oral mucosa, scar/keloid tissue showing highest values. Positivity for both the markers was seen in epithelium, around the blood vessels, in areas of inflammatory infiltrate, fibroblasts and in muscles. TGF-β1 expression was higher and more intense than that of TGF-β2 in all the cases. TGF-β2 was restricted in its expression to submucosal area with minimal involvement of the epithelium and the deeper muscle tissue. Conclusion: TGF-β1 is the most prominent cytokine in the fibrotic pathway and TGF-β2 plays a contributory role.
Early life modulators and predictors of adult synaptic plasticity

Early life experience can induce long‐lasting changes in brain and behaviour that are opposite in direction, such as enhancement or impairment in regulation of stress response, structural and functional integrity of the hippocampus, and learning and memory. To explore how multiple early life events jointly determine developmental outcome, we investigated the combined effects of neonatal trauma (anoxia on postnatal day 1, P1) and neonatal novelty exposure (P2–21) on adult social recognition memory (3 months of age) and synaptic plasticity in the CA1 of the rat hippocampus (4.5–8 months of age). While neonatal anoxia selectively reduced post‐tetanic potentiation (PTP), neonatal novel exposure selectively increased long‐term potentiation (LTP). No interaction between anoxia and novelty exposure was found on either PTP or LTP. These findings suggest that the two contrasting neonatal events have selective and distinct effects on two different forms of synaptic plasticity. At the level of behaviour, the effect of novelty exposure on LTP was associated with increased social memory, and the effect of anoxia on PTP was not accompanied by changes in social memory. Such a finding suggests a bias toward the involvement of LTP over PTP in social memory. Finally, we report a surprising finding that an early behavioural measure of emotional response to a novel environment obtained at 25 days of age can predict adult LTP measured several months later. Therefore, individual differences in emotional responses present during the juvenile stage may contribute to adult individual differences in cellular mechanisms that underlie learning and memory.
Reachability analysis of rational eigenvalue linear systems

One of the key problems in the safety analysis of control systems is the exact computation of reachable state spaces for continuous-time systems. Issues related to the controllability and observability of these systems are well-studied in systems theory. However, there are not many results on reachability, even for general linear systems. In this study, we present a large class of linear systems with decidable reachable state spaces. This is approached by reducing the reachability analysis to real root isolation of exponential polynomials. Furthermore, we have implemented this method in a Maple package based on symbolic computation and applied to several examples successfully.