IUPUI Research Day 2015

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https://hdl.handle.net/1805/6250

A program book describing the Research Day 2015 events and posters is available from: http://hdl.handle.net/1805/9289.

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Biomarker of Magnesium Status in Response to Mg Supplementation: A Dose- and Time-Response Meta-analysis of Randomized Controlled Trials
(Office of the Vice Chancellor for Research, 2015-04-17) Zhang, Xi; Song, Yiqing
ABSTRACT Background: Magnesium is a cofactor for hundreds of human enzymes and magnesium deficiency has been associated with cardiometabolic disorders. Although a panel of magnesium biomarkers are used to assess magnesium status, their relative predictive values or clinical usefulness in response to magnesium supplementation remain unclear. Objective: We quantitatively evaluated time- and dose-response relation of magnesium biomarkers from available randomized controlled trials (RCTs) of magnesium supplementation. Methods: We systematically identified RCTs assessing magnesium biomarkers’ responses after oral magnesium supplementation through search on MEDLINE and Cochrane Library up to November 2014. We calculated the pooled weight mean differences (WMDs) of biomarkers levels between treatment and placebo group after supplementation. A dose- and time-response meta-analysis was conducted to quantitatively compare the usefulness of biomarkers in assessing magnesium status. Results: This meta-analysis included 44 RCTs of magnesium supplementation that examined a total of 38 biomarkers of magnesium status. Total magnesium concentrations in blood (serum or plasma), RBC, and urine were significantly raised after magnesium supplementation by 0.05 mmol/l, 0.12 mmol/l, and 1.52 mmol/24h corresponding to 5.81%, 5.30%, and 28.3% increases relative to baseline magnesium levels, respectively. Our dose- and time-response meta-analyses showed that blood and urinary magnesium levels abruptly increased at the first 20-week supplementation and afterwards reached a plateau. Evidence was insufficient due to limited numbers of studies testing other potential biomarkers, including ionized Mg, muscle Mg, mononuclear Mg, intracellular Mg, IV Mg load, ultrafiltrable Mg, and fecal Mg.
Sintering Mechanisms and Mechanical Properties of 3D Printed Metals
(Office of the Vice Chancellor for Research, 2015-04-17) Zhang, Yi; Zhang, Jing
Nickel and iron based alloys are widely used as raw materials in 3D printing or additive manufacturing process. In direct metal laser sintering (DMLS) process, a primary 3D printing technique for metals, metallic powders are sintered to a desired shape by heat energy from a laser beam. This study presents a molecular dynamics study to simulate the sintering process and resultant mechanical properties of 3D printed metal parts. The model will elucidate and quantify the diffusion process during 3D printing of nickel and iron powders. Further, to study the mechanical properties of the sintered nickel parts, uniaxial tensile test simulations will be performed on the parts sintered at different heating rates. The calculated diffusion activation energy for nickel is 7.91 KJ/mole in the nickel particle core region; and 8.55 KJ/mole on the surface area, respectively, which agrees well with the experimentally measured data from literature. Uniaxial tensile test simulation results show that a higher heating rate will increase the mechanical strength of sintered material.
Novel Lanthanum Zirconate Thermal Barrier Coatings for Gas Turbines
(Office of the Vice Chancellor for Research, 2015-04-17) Zhang, Jing; Guo, Xingye; Jung, Yeon-Gil; Li, Li; Knapp, James
Pyrochlore lanthanum zirconate (La2Zr2O7) is a very promising candidate material for thermal barrier coating (TBC) applications. Layered microstructure was designed and prepared using air plasma spray to improve the thermal durability. The physical, mechanical and thermal properties of the coatings were measured. La2Zr2O7 shows outstanding phase stability in high temperatures and lower thermal conductivity than commercial 8YSZ TBCs material. Coating lifetime performance was also estimated through the JETS (Jet Engine Thermal Simulation) and TGMF (Thermal Gradient Mechanical Fatigue) tests.
Name Disambiguation from link data in a collaboration graph
(Office of the Vice Chancellor for Research, 2015-04-17) Zhang, Baichuan; Saha, Tanay Kumar; Al Hasan, Mohammad
Abstract—The entity disambiguation task partitions the records belonging to multiple persons with the objective that each decomposed partition is composed of records of a unique person. Existing solutions to this task use either biographical attributes, or auxiliary features that are collected from external sources, such as Wikipedia. However, for many scenarios, such auxiliary features are not available, or they are costly to obtain. Besides, the attempt of collecting biographical or external data sustains the risk of privacy violation. In this work, we propose a method for solving entity disambiguation task from link information obtained from a collaboration network. Our method is nonintrusive of privacy as it uses only the timestamped graph topology of an anonymized network. Experimental results on two reallife academic collaboration networks show that the proposed method has satisfactory performance.
The IUPUI Center for HPV Research: Updates 2014-2015
(Office of the Vice Chancellor for Research, 2015-04-17) Zimet, Gregory D.; Fortenberry, J. Dennis
Background: Human papillomavirus (HPV) is a very common infection. High risk (HR) HPV types (particularly types 16 & 18) are causally implicated in many cancers, including cervical, anal, vaginal, vulvar, penile, and head and neck cancers. In an effort to address the problems associated with HPV infection and prevention, the Center for HPV Research at IUPUI (Zimet & Fortenberry, Co-Directors) fosters collaboration among investigators from multiple disciplines and departments at IUPUI, IU Bloomington, Purdue University, and University of Notre Dame. There currently are 32 faculty and 8 pre- and post-doctoral fellows who are members of the Center. The Center for HPV Research was established in July, 2012 with funds from the IUPUI Signature Center Initiative, the Department of Pediatrics, and the IU Simon Cancer Center. Over the past year, Center members had 6 external & internal grants funded, 5 additional grants submitted, 8 peer-reviewed articles published, and gave over 20 scientific conference and invited presentations. In this abstract we highlight a study representing a collaboration among 5 center members, with Dr. Marcia Shew as the lead and including an MPH student. Objectives: Most HR HPV infections do not progress to cancer, but progression is associated with persistent infection. HPV was previously thought to "clear" or persist, but newer studies suggest that HPV may be a latent virus that can be re-detected episodically. This study examined the persistence and/or redetection of HR HPV in young women recruited 6 years after identification of a HR HPV infection during their prior involvement in a longitudinal study of adolescent women. Methods: 30 women from the prior study (the Young Women’s Project) were recruited for 2 visits, 6 weeks apart. During Visit 1 they had a Pap test, HPV DNA testing, HPV serology, and were administered a semi-structured interview. During Visit 2, Pap test results were given, a self-swab for HPV testing was obtained, and a qualitative interview was administered. Results: 15 women had normal Pap test results, 2 were ASCUS, and 3 LGSIL. 12 women had a history of colposcopy for a previous abnormal Pap results and 4 had received treatment for cervical dysplasia. 26 of the women had HPV 16 in the original YWP study. 11 had HPV 16 redetected in the present study, including in 6 women who had apparently "cleared" the infection during the original YWP study. Conclusions: High risk HPV may not always (or ever) "clear" Persistent low viral levels may not be detectible. However, some HPV infections may be episodically detected if changes in immune function lead to increases in viral copies. Questions raised by this research include: 1) who is at risk for episodic detection?; 2) what factors are predictive of episodic detection?; 3) how likely is episodically-detect HR HPV to progress to cervical disease?; 4) what is the predictive value of a negative HPV DNA test?; and 5) what do we tell women with a positive HR HPV DNA screen if they have been sexually abstinent or with a life-long partner ... or if they have a new partner?
Social Support and Well-being: A Quantitative Study of the Effects of Friendship on the Sexual Well-being of Older Adults
(Office of the Vice Chancellor for Research, 2015-04-17) Williams, Monica M.
Background: Social support has been shown to positively impact various aspects of health across the lifespan, including sexual health and well-being. While past research on sexual well-being has tended to focus on the earlier stages of the life course, notably adolescence and young adulthood, this is a largely ignored area of research past the reproductive stage of life. Current research finds that while social support, from partners, family, and friends alike, has generally positive influences on health in mid to late adulthood, these outcomes are varied in regards to sexual well-being. Objectives: This study aims to (1) assess the role of friend support in the sexual wellbeing of older adults and (2) to explore if physical and mental health are significant mediators of this relationship. Methods: This study uses data from Wave II of the National Social Life, Health, and Aging Project (NSHAP), a longitudinal, population-based study of health and social factors, aiming to understand the well-being of older, community-dwelling adults. Using binary logistic regression, a series of models were created to evaluate whether social support of friends is a significant predictor of sexual well-being in older adults and whether that relationship is reduced with the introduction of each mediator individually. Covariates included age, race, gender, education, partner status, presence of close family members, and sexual functioning. Results: Sixty two percent of older adults are not having sex as much as they would like and 61% feel that their sex life is lacking in quality. Significant correlates of satisfaction of sex frequency include having a romantic partner (OR .209; p<.000), reliable friends (OR 1.366; p=.010) and sexual dysfunction (OR 1.257; p<.000). Significant correlates of quality of sex life included gender (OR .636; p=.001), education (OR 1.136, p=.037), and sexual dysfunction (OR 1.355; p=.000). Neither mental health nor physical health status were significant mediators of the dependent variables. Conclusion: Similar to findings related to sexual well-being and familial support and reliance (Wait and Das 2010), this study showed that having reliable friends actually decreased the likelihood of satisfaction with sex frequency, one important aspect of sexual well-being. While this relationship may be due to friendship being a proxy for romantic relationships, more research is needed to ascertain the cause of this relationship.
Posterior sub-Tenon capsule anesthesia for photocoagulation treatment of diabetic retinopathy performed in an inner-city county hospital clinic setting
(Office of the Vice Chancellor for Research, 2015-04-17) Wise, Ryan J.; Pattar, Guruprasad R.; Xie, Jun; Phan, Anh-Danh T.
Proliferative diabetic retinopathy (PDR) is a blinding eye disease demanding prompt therapy. However, treatment with panretinal photocoagulation (PRP) can be painful thereby limiting its extent. In addition, compliance to diabetic eye visits remains poor particularly in inner cities. Therefore, it is imperative to optimize treatment during clinic visits. The purpose of this study is to present the effect of sub-Tenon (Sub-T) capsule lidocaine anesthesia on PRP treatment extent for PDR performed during the eye clinic visit. This is an IRB-approved retrospective review of initial 12 eyes (9 subjects) with PDR undergoing PRP treatment involving Sub-T anesthesia in the eye clinic. Sub-T capsule lidocaine anesthesia was delivered and PRP was immediately performed. Primary end point was extent of treatment (number of PRP laser spots) delivered. Comparison was made to PRP in prior sessions without Sub-T anesthesia. All subjects had active PDR and sometimes vitreous hemorrhage (VH) at time of treatment. Decision was made to offer Sub-T anesthesia due to intolerable pain from prior PRP treatments in all subjects. We observed all subjects were able to tolerate a significantly greater extent of PRP with Sub-T anesthesia even with presence of VH, oftentimes undergoing thousands of laser spots and capable to complete treatment in same clinic visit. By comparison, prior PRP treatments (without Sub-T anesthesia) were much less extensive sometimes involving only a few laser spots. We conclude that Sub-T anesthesia allows a tier of pain control for those not able to tolerate traditional PRP without anesthesia performed in the eye clinic. This new information suggests that certain patients undergoing PRP can be offered Sub-T anesthesia, and it will be important to define algorithm for selection of such individuals.
Sirt6 Regulates Insulin Secretion from the Pancreatic Beta Cells
(Office of the Vice Chancellor for Research, 2015-04-17) Xiong, Xiwen; Wang, Gaihong; Tao, Rongya; Wu, Pengfei; Kono, Tatsuyoshi; Tong, Xin; Tersey, Sarah A.; Harris, Robert A.; Evans-Molina, Carmella; Mirmira, Raghavendra G.; Dong, X. Charlie
Sirt6 is an NAD-dependent histone deacetylase, which is involved in multiple biological processes, including aging, DNA repair, and metabolism; however, it is unclear what its functions in pancreatic beta-cells are. The beta cells play an essential role in metabolic regulation by secreting insulin in response to an elevated glucose concentration in the circulation. To examine the role of Sirt6 in beta cells, we initially used adenovirus-mediated shRNA to knock down the Sirt6 gene expression in a mouse pancreatic beta cell line - MIN6. Knockdown of the Sirt6 gene significantly reduced glucose-stimulated insulin secretion. To further validate this phenotype in vivo, we generated pancreatic beta-cell-specific Sirt6 knockout mice (bKO) using mouse genetic approach. Indeed, the bKO mice showed remarkable impairment in both first and second phases of insulin secretion in response to a glucose load. While morphometric analyses did not reveal significant difference in islet area between wild-type and bKO mice, biochemical analysis of ATP concentrations showed a 22% decrease in bKO mouse islets relative to control wild-type islets after glucose stimulation. To assess mitochondrial function in Sirt6-deficient beta cells, we also performed Seahorse bioenergetics assays in MIN6 cells after the Sirt6 gene was knocked down. Glucose oxidation in mitochondria was decreased 20-30% in Sirt6- knockdown MIN6 cells as compared to the control cells. Since calcium signaling is critical to insulin secretion, we also measured intracellular calcium concentrations using a fluorescent imaging approach. The results showed a significant decrease in cytoplasmic calcium in the bKO islets as compared to the wild-type controls. Overall, our data demonstrate that Sirt6 plays a critical role in the regulation of pancreatic insulin secretion. This work was supported in part by the NIDDK grant R01DK091592.
Polarization Analysis Based on Realistic Lithium Ion Battery Electrode Microstructure Using Numerical Simulation
(Office of the Vice Chancellor for Research, 2015-04-17) Yan, Bo; Lim, Cheolwoong; Song, Zhibin; Zhu, Likun
The performance of lithium ion battery (LIB) is limited by the inner polarization and it is important to understand the factors that affect the polarization. This study focuses on the polarization analysis based on realistic 3D electrode microstructures. A c++ software was developed to rebuild and mesh the microstructure of cathode and anode electrodes through Nano-CT and Micro-CT scanned images respectively. As a result, the LIB model was composed of electrolyte, cathode and anode active materials and current collectors. By employing 3D finite volume method (FVM), another c++ code was developed to simulate the discharge and charge processes by solving coupled model equations. The simulation revealed the distribution of physical and electrochemical variables such as concentration, voltage, current density, reaction rate, et al. In order to explore the correlation of local effects and electrode structural heterogeneity, the cathode electrode were divided equally into 8 sub-divisions, of which the porosity, tortuosity, specific surface area were calculated. We computed the polarizations in the sub-divisions due to different sub-processes, i.e., the activation of electrochemical reactions and charge transport of species. As shown in Fig. 1, the tortuosity is very irregular because of unevenly distributed cathode particle size and packing pattern with low porosity. There are no exact and direct relations among porosity, tortuosity and specific surface area. Fig. 2 shows that the polarizations are related to the porosity in sub-divisions. The knowledge from the study will help to figure out the mechanism of polarization and power loss in LIB, which could be useful to improve LIB design and manufacturing. Acknowledgments: This work was supported by US National Science Foundation under Grant No. 1335850. Fig. 1 Porosity and tortuosity in sub-divisions of a cathode electrode Fig. 2 Intercalation reaction polarization and ionic conduction polarization of sub-divisions at 120 sec during a 5 C charging process
Identifying Metabolic Pathways Producing Alkamides in Echinacea purpurea
(Office of the Vice Chancellor for Research, 2015-04-17) Williams, Jermell; Teitgen, Alicen; Minto, Robert E.
Echinacea purpurea is a widely used herbal supplement that is frequently taken to relieve cold symptoms; alkamides are believed to be the bioactive agent. Alkamides are natural products found throughout the Echinacea genus that contain fatty acid chains incorporated into amides. Our goal is to identify and understand the specific metabolic processes by which E. purpurea produces alkamides. In our experiment Echinacea seedlings were grown to the point where the first true leaf started to grow and alkamide production is known to be active. Alkamides were then extracted and taken to the GC/MS for analysis. Extracted alkamides were analyzed by triple-quadrupole chromatography to investigate 13C labeling by glucose. We are currently in the process of examining the spectra in order to determine the structures of the alkamides as well as any metabolic relationships and if these are altered by a lack of light.

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