Indiana University-Purdue University Indianapolis (IUPUI) / Environmental exposure to lead (Pb) and cannabis use are two of the largest public health issues facing modern society in the United States and around the world. Exposure to Pb in early life has been unequivocally shown to have negative impacts on development, and recent research is mounting showing that it may also predispose individuals for risk of developing substance use disorders (SUD). At the same time, societal and legal attitudes towards cannabis (main psychoactive component delta-9-tetrahydrocannabinol) have been shifting, and many American states have legalized the recreational use of cannabis. It is also the 3rd most widely used drug of abuse in the US, and rates of cannabis use disorder are on the rise. This thesis sets out to establish whether there is a link between early life Pb exposure and later THC-related behavior in C57BL6/J mice, as has been demonstrated for other drugs of abuse. The first aim seeks to answer whether Pb exposure affects physiological THC sensitivity (as measured by the cannabinoid-induced tetrad). The second aim seeks to answer whether Pb exposure affects edible THC self-administration and the development of THC tolerance (also measured by the tetrad). It was hypothesized that Pb exposure would decrease THC sensitivity (Aim 1), would enhance THC self-administration (Aim 2), enhance the development of THC tolerance (Aim 2), and finally that sex-dependent effects of Pb-exposure and THC would be observed (Aims 1 & 2). These hypotheses ended up not being supported, but Aim 1 produced findings indicating that THC sensitivity was increased by Pb exposure, but only in female mice. Future research will hopefully be able to fully explore the implications of these findings.

Piezoelectric materials find applications in number of devices requiring inter-conversion of mechanical and electrical energy.  These devices include different types of sensors, actuators and energy harvesting devices. A number of lead-based perovskite compositions (PZT, PMN-PT, PZN-PT etc.) have dominated the field in last few decades owing to their giant piezoresponse and convenient application relevant tunability. With increasing environmental concerns, in the last one decade, focus has been shifted towards developing a better understanding of lead-free piezoelectric compositions in order to achieve an improved application relevant performance.  Sodium potassium niobate (KxNa1-xNbO3, abbreviated as KNN) is one of the most interesting candidates in the class of lead-free piezoelectrics. Absence of any poisonous element makes it unique among all the other lead-free candidates having presence of bismuth. Curie temperature of 400"C, even higher than that of PZT is another advantage from the point of view of device applications. Present work focuses on the development of fundamental understanding of the crystallographic nature, domain structure and domain dynamics of KNN. Since compositions close to x = 0.5 are of primary interest because of their superior piezoelectric activity among other compositions (0 < x < 1), crystallographic and domain structure studies are focused on this region of the phase diagram. KNN random ceramic, textured ceramic and single crystals were synthesized, which in complement to each other help in understanding the behavior of KNN. K0.5Na0.5NbO3 single crystals grown by the flux method were characterized for their ferroelectric and piezoelectric behavior and dynamical scaling analysis was performed to reveal the origin of their moderate piezoelectric performance. Optical birefringence technique used to reveal the macro level crystallographic nature of x = 0.4, 0.5 and 0.6 crystals suggested them to have monoclinic Mc, monoclinic MA/B and orthorhombic structures respectively. Contrary to that, pair distribution function analysis performed on same composition crystals implies them to belonging to monoclinic Mc structure at local scale. Linear birefringence and piezoresponse force microscopy (PFM) were used to reveal the domain structure at macro and micros scales respectively. A noble sintering technique was developed to achieve > 99% density for KNN ceramics. These high density ceramics were characterized for their dielectric, ferroelectric and piezoelectric properties. A significant improvement in different piezoelectric coefficients of these ceramics validates the advantages of this sintering technique. Also lower defect levels in these high density ceramics lead to the superior ferroelectric fatigue behavior as well. To understand the role of seed crystals in switching behavior of textured ceramic, highly textured KNN ceramics (Lotgering factor ~ 88 %) were synthesized using TGG method. A sintering technique similar to one employed for random ceramics, was used to sinter textured KNN ceramics as well. Piezoresponse force microscopy (PFM) study suggested these textured ceramics to have about 6¼m domains as compared to 2¼m domain size for random ceramics.  Local switching behavior studied using switching spectroscopy (SS-PFM) revealed about two and half time improvement of local piezoresponse as compared to random counterpart. / Ph. D.

Lead is a central nervous system poison. Healthy People 2010 established a target blood lead level (BLL) for children of 0 μg/dL by 2010, but is silent with regard to any changes in BLLs standards for working age adults. In this paper, the relation of BLL to performance on two neurobehavioral tests was assessed in working age adults (N = 4909; Age 20 to 59 years; 51.4% Female) employing data from the Third National Health and Nutrition Survey (NHANES 111). Multiple linear regression analyses indicated a significant effect of BLL on time taken to complete an attention demanding cognitive task (Symbol Digit Substitution Task, SDST) but not accuracy of performance of the SDST or simple reaction time, after controlling for confounding variables of age, sex, race-ethnicity, and education. Persons with BLL ≥5 μg /dL took longer (multivariate adjusted mean = 23.6 Sec, SE = 0.30) compared to individuals with BLLs <5 μg /dL (mean = 22.5 Sec, SE = 0.14). The results suggest that lead burden in working age persons impairs central nervous processes involving executive mental functions (decision speed and attention). The findings, if confirmed by case control and or cohort studies would indicate a need to reconsider currently accepted lead levels in working age adults.

Between May 1985 and December 1986, a cohort of 1,502 pregnant women was recruited at two government clinics in Kosovo (formerly a province of Yugoslavia) for a study of the relationship between environmental lead (Pb) exposure and birth outcomes. Subsequently, a representative group of 541 of their children were selected for long-term follow up. The children were followed longitudinally at six-month intervals for 12 years to examine the effects of environmental Pb exposure on a variety of health outcomes including cognitive and motor function, anemia, endocrine function and growth. This work produced numerous landmark publications (Popovac et al, 1982; Graziano et al., 1990, 1991, 2004; Murphy et al., 1990; Factor-Litvak et al, 1993, 1996, 1998, 1999; Wasserman et al,. 1992, 1994, 1997, 1998, 2000) that contributed to the modification of environmental policies to reduce Pb exposure worldwide. The long-term study ultimately linked environmental Pb exposure from the Trepca mining and smelting operations in Mitrovica to adverse effects on intelligence, motor function, blood pressure, renal, endocrine and hematological functioning. Follow up rates over time were excellent in that 70% of the total cohort was evaluated at 6 years of age, and 65% were evaluated at 12 years of age, at which point the study was - until now - concluded. For the present study, we located 101 members of the original study cohort and requested their participation in a follow-up study in which participants were evaluated to assess their current blood lead (BPb) levels and health outcomes as follows: a) blood pressure; b) biomarkers of endothelial cell function that are associated with cardiovascular disease; c) and measurements of erythropoietin, a glycoprotein hormone produced in the kidney that regulates the production of red blood cells in the bone marrow. The participants, whose environmental exposure history is very well documented from 12 weeks of gestation through 12 years of age, were between 25-26 years of age during the follow-up study. We found a statistically significant association between BPb and systolic blood pressure (sBP), and a marginally significant association between BPb and diastolic blood pressure (dBP), which is consistent with a multitude of studies and meta-analyses referenced in this dissertation. These results provide further evidence that recent circulating dose, as estimated by BPb, or as estimated by lifetime cumulative exposure, is associated with slight increase in sBP. Furthermore, we detected a suggestive relationship between BPb and levels of circulating serum intercellular adhesion molecules (sICAM-1) and serum intravascular adhesion molecules (sVCAM-1), possibly a mechanism by which Pb may lead to increased BP. These findings support the hypothesis that the exposure to Pb either prenatally or in early adulthood, may lead to increased BP and increased circulating levels of sICAM-1 and sVCAM-1 later in life. Lastly, the results regarding the serum erythropoietin (EPO) production presented here resemble the findings reported in this cohort at 4.5 and 6.5 years of age and in contrast with the findings in this cohort when the study participants were 9.5 and 12 years of age (Graziano et al., 2004). In addition, they also contrast the findings reported in the anemic mothers of this study cohort (Graziano et al., 1991) where serum-EPO levels were lower in those with higher BPb levels.

Thesis--University of Missouri, School of Mines and Metallurgy, 1903. / R.T. Rolufs determined to be Roluf Theodore Rolufs from "Thirty-Third Annual Catalogue of the School of Miens and Metallurgy." The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed Nov. 3, 2008).

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1929. / Figures 2-5 and Tables 1-5 are missing from text document. The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed October 1, 2009)

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 152-160).

OBJECTIVES: Despite continued efforts to decrease environmental lead exposure, it remains a public health concern in the U.S. The aim of this study was to investigate the influence of lead exposure on dental caries risk among different populations. METHODS: We used data from Detroit Dental Health Project (DDHP), a cohort study of a representative sample of low-income African–American families in Detroit, Michigan, to investigate the influence of lead toxicity on dental caries risk among children, and to assess the effect of blood lead level on the caries experience among their caregivers. Data from Dental Longitudinal Study (DLS), a closed-panel prospective cohort study of oral health and aging, was used to assess the cross-sectional and longitudinal relationships between bone lead level as a cumulative measure of lead exposure and dental caries among older men. The outcome measure for cross-sectional analyses was dmfs/DMFS, which is the number of decayed surfaces, missing, and filled surfaces for each subject. Then adjusted new dmfs/DMFS increments were used for the longitudinal analyses. Descriptive and bivariate analyses were conducted on dental caries outcome by lead biomarkers. Multiple regression and GEE models were conducted controlling for confounding. RESULTS: History of lead toxicity (≥ 10µg/dl) and children’s caries risk was significantly associated in both cross-sectional analysis (PR = 1.50, p-value=0.003) and longitudinal analysis (IRR= 1.36, p-value=0.02). These associations were independent of confounding factors such as age, brushing frequency, soda consumption, income, and child and caregiver’s caries experience. On other hand, no significant associations were found between blood lead level and dental caries experience among African American adults (β=2.3, p-value=0.5), nor between high tibia/patella lead level and dental caries incident among older adult (β=0.1, p-value=0.7 for tibia, and β=0.3, p-value=0.1 for patella) . CONCLUSION: The results suggest that children with a history of lead toxicity are at a higher risk of developing dental caries compared to other children. However, there is no significant association between lead exposure and dental caries among adults. Therefore, children with a history of lead toxicity should be given special consideration in caries risk assessment and caries prevention programs. / 2019-09-26T00:00:00Z

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