Medicine and Health Sciences Commons^™

The Digital Society, Place

PLACE Historical Documents

This document explains the PLACE theme at Linfield College for 2016-2018 (The Digital Society).

Peroxiredoxin Catalysis At Atomic Resolution, Arden Perkins, Derek Parsonage, Kimberly J. Nelson, O. Maduka Ogba, Paul Ha-Yeon Cheong, Leslie B. Poole, P. Andrew Karplus

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peroxiredoxins (Prxs) are ubiquitous cysteine-based peroxidases that guard cells against oxidative damage, are virulence factors for pathogens, and are involved in eukaryotic redox regulatory pathways. We have analyzed catalytically active crystals to capture atomic resolution snapshots of a PrxQ-subfamily enzyme (from Xanthomonas campestris) proceeding through thiolate, sulfenate, and sulfinate species. These analyses provide structures of unprecedented accuracy for seeding theoretical studies, and show novel conformational intermediates giving insight into the reaction pathway. Based on a highly non-standard geometry seen for the sulfenate intermediate, we infer that the sulfenate formation itself can strongly promote local unfolding of the active site to …

Rickettsiologist Pavel F. Zdrodovskii: Larger Than Life, And Not Just For His Famous Book, Marina E. Eremeeva, S. N. Shpynov, I. V. Tarasevich

Environmental Health Sciences: Faculty Publications

This article highlights the biography and scientific accomplishments of Pavel F. Zdrodovskii and his contributions to understanding the biology, pathogenesis, treatment, prevention and epidemiology of brucellosis, rickettsioses and many other infectious diseases.

Role Of Hearth Program With Undernutrition Incidence Among Toddlers In Tangerang City, Gizella Gizella, Dany Hilmanto, Dedi Rachmadi

Kesmas

Kelompok yang rentan terhadap gizi kurang adalah balita. World Health Organization (WHO) menyatakan kematian anak bawah lima tahun (balita) akibat gizi kurang sebesar 54% pada tahun 2002. Di Indonesia, prevalensinya mengalami peningkatan dari 17,9% pada tahun 2010 menjadi 19,6% pada tahun 2013. Di Kota Tangerang, terdapat 1,43% balita yang mengalami gizi buruk pada tahun 2013. Penelitian ini bertujuan untuk membuktikan secara valid hubungan antara Program Pos Gizi yang meliputi perilaku pemberian makan, perilaku kebersihan balita, perilaku mencari pelayanan kesehatan dan perilaku pengasuhan balita dengan kejadian gizi kurang pada balita. Penelitian ini merupakan penelitian kuantitatif, potong lintang, menggunakan data primer serta …

Good Corporate Governance Implementation And Performance Of Civil Servant, Muhammad Hasan, Dumilah Ayuningtyas, Misnaniarti Misnaniarti

Kesmas

Dalam rangka mencapai visi dan misi, setiap rumah sakit harus menjalankan tata kelola perusahaan yang baik (Good Corporate Governance/GCG). Penerapan GCG sendiri bertujuan untuk meningkatkan kinerja pegawai secara optimal, yang akhirnya akan meningkatkan kinerja organisasi. Penelitian ini bertujuan untuk menganalisis hubungan penerapan prinsip-prinsip GCG terhadap kinerja pegawai negeri sipil (PNS) Rumah Sakit Umum Lapangan Natuna Kabupaten Kepulauan Anambas. Jenis penelitian ini adalah deskriptif analitik dengan desain potong lintang pada 56 PNS. Pengumpulan data dilakukan pada tahun 2012 dengan kuesioner terstruktur. Digunakan analisis dengan uji kai kuadrat dan regresi logistik, dan untuk penyederhanaan model dilakukan eliminasi terhadap faktor perancu dengan menggunakan …

Environmental, Behavioral Factors And Filariasis Incidence In Bintan District, Riau Islands Province, Zainul Ikhwan, Lucky Herawati, Suharti Suharti

Kesmas

Tingkat mikrofilaria filariasis di Kabupaten Bintan masih tinggi, khususnya di Kecamatan Teluk Bintan, Teluk Sebong, dan Sri Kuala Lobam. Penelitian ini bertujuan untuk mengetahui hubungan faktor risiko lingkungan (faktor fisik, biologi, kimia, sosial budaya, ekonomi) dan faktor perilaku dengan kejadian filariasis. Jenis penelitian observasional analitik yang dilakukan pada Mei – September 2015 dengan desain kasus kontrol, yang terdiri dari jumlah kasus 33 orang penderita filariasis dan kontrol 65 orang bukan penderita filariasis dengan teknik cluster sampling. Populasi penelitian adalah masyarakat di Kabupaten Bintan. Data yang diperoleh dianalisis menggunakan uji kai kuadrat dan regresi logistik. Hasil menunjukkan adanya hubungan pengetahuan (nilai …

Variation Of Driving Skill Among Elderly Drivers Compared To Young Drivers In Japan, Indri Hapsari Susilowati, Akira Yasukouchi

Kesmas

Penelitian ini menganalisis kemampuan mengemudi pada pengemudi lanjut usia (lansia) dibandingkan dengan usia muda di Jepang dan melihat keterampilan mengemudi yang kurang sehingga dapat memengaruhi risiko kecelakaan di jalan raya. Subjek penelitian adalah pengemudi usia muda dan lansia, terdiri dari 10 mahasiswa (20 - 24 tahun) dan 25 pengemudi lansia (14 laki-laki dan 11 perempuan) berasal dari The Silver Menpower Center, organisasi bagi lansia > 60 tahun. Pengemudi lansia dibagi menjadi dua kelompok, yaitu lansia 1 berusia 60 - 65 tahun (10 orang) dan lansia 2 berusia > 65 tahun (15 orang). Kemampuan mengemudi dievaluasi dengan simulator permainan mengemudi dalam laboratorium. Analisis …

Rural-Based Health Promotion Model For Pregnant Women In Banyumas District, Elviera Gamelia, Dian Anandari, Dyah Umiyarni Purnamasari

Kesmas

Penelitian sebelumnya menunjukkan bahwa pengetahuan pelayanan prenatal di wilayah pedesaan masih rendah yang berdampak pada perilaku buruk sehingga mengembangkan model promosi kesehatan dibutuhkan untuk meningkatkan pengetahuan prenatal, sikap dan perilaku. Penelitian ini bertujuan untuk mengembangkan model promosi kesehatan pelayanan prenatal di wilayah pedesaan berdasarkan penilaian kebutuhan. Penelitian dilakukan pada Juni 2015 dengan pendekatan kualitatif melibatkan 16 ibu hamil pertama di trimester ketiga dengan kehamilan berisiko sebagai informan kunci dan 16 anggota keluarga yang tinggal bersama ibu hamil dan mengetahui kehidupan sehari-harinya, 27 bidan dan 3 tokoh agama sebagai informan tambahan. Teknik pengumpulan data adalah wawancara mendalam dan observasi untuk ibu …

Well Water Consumed And Urolithiasis In Gedangsari Subdistrict, Yogyakarta, Sulistyawati Sulistyawati, Fardhiasih Dwi Astuti, Ruri Trisasri, Asep Rustiawan

Kesmas

Tanah di wilayah Kecamatan Gedangsari mengandung batuan kapur. Masyarakat di daerah ini banyak yang mengkonsumsi air minum dari sumur gali yang mengandung kadar kalsium tinggi, dan banyak yang menderita urolithiasis. Penelitian ini bertujuan untuk mendapatkan gambaran distribusi kalsium atau Ca(OH)2 pada air sumur dan menjelaskan hubungannya dengan kejadian urolithiasis. Penelitian dilakukan di Kecamatan Gedangsari, Kabupaten Gunungkidul selama Juli sampai November 2013. Penelitian dilakukan secara potong lintang dengan konfirmasi uji titrasi di laboratorium. Sejumlah 94 sampel sumur dipilih secara acak dari populasi 3.849 sumur. Kriteria pemilihan sampel adalah sumur gali yang telah digunakan untuk minum oleh penduduk berusia lebih dari 30 …

Identification Of Pathogenic Leptospira In Rat And Shrew Populations Using Rpob Gene And Its Spatial Distribution In Boyolali District, Dyah Widiastuti, Zumrotus Sholichah, Agustiningsih Agustiningsih, Nastiti Wijayanti

Kesmas

Leptospirosis merupakan masalah kesehatan di Indonesia. Hingga April 2014, dilaporkan kasus leptospirosis yang ditularkan oleh tikus di Kabupaten Boyolali dengan angka kematian 83,3%. Genus Leptospira terdiri dari ratusan serovar dan tipe genetik yang hidup di pelbagai jenis habitat. Pengelompokan spesies Leptospira berdasarkan gen rpoB dapat digunakan karena tingkat polimorfisme gen tersebut tinggi. Penelitian ini bertujuan untuk mengidentifikasi serovar bakteri Leptospira pada populasi tikus di Kabupaten Boyolali menggunakan analisis hubungan kekerabatan didasarkan pada polimorfisme gen rpoB dan menggambarkan distribusi spasial tikus positif Leptospira di Kabupaten Boyolali. Penelitian potong lintang dilaksanakan pada bulan April 2014 di Desa Sindon Kecamatan Ngemplak dan Desa …

Measles Immunization And Vitamin A For Prevention Of Pneumonia In Indonesia, Ratno Widoyo

Kesmas

Pneumonia merupakan penyebab kematian tertinggi pada anak di Indonesia setelah diare. Pengendalian pneumonia dapat dilakukan dengan peningkatan cakupan imunisasi campak, pertusis, Streptococcus pneumoniae (Spn), dan Haemophilus influenzae b (Hib). Vaksin Spn dan Hib belum masuk ke dalam kategori imunisasi wajib di Indonesia. Vaksin campak lebih memiliki pengaruh langsung terhadap pneumonia dibandingkan dengan vaksin pertusis. Pemberian imunisasi yang disertai pemberian vitamin A akan meningkatkan titer antibodi pada anak. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian imunisasi campak dan vitamin A terhadap kejadian pneumonia. Metode penelitian adalah potong lintang dengan menggunakan 13.062 data anak yang terdapat pada data Survei Demografi dan Kesehatan …

Bayesian Peer Calibration With Application To Alcohol Use, Miles Q. Ott, Joseph W. Hogan, Krista J. Gile, Crystal Linkletter, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

Peers are often able to provide important additional information to supplement self-reported behavioral measures. The study motivating this work collected data on alcohol in a social network formed by college students living in a freshman dormitory. By using two imperfect sources of information (self-reported and peer-reported alcohol consumption), rather than solely self-reports or peer-reports, we are able to gain insight into alcohol consumption on both the population and the individual level, as well as information on the discrepancy of individual peer-reports. We develop a novel Bayesian comparative calibration model for continuous, count and binary outcomes that uses covariate information to …

Diffuse Optical Measurements Of Head And Neck Tumor Hemodynamics For Early Prediction Of Chemoradiation Therapy Outcomes, Lixin Dong, Mahesh Kudrimoti, Daniel Irwin, Li Chen, Sameera Kumar, Yu Shang, Chong Huang, Ellis L. Johnson, Scott D. Stevens, Brent J. Shelton, Guoqiang Yu

Biomedical Engineering Faculty Publications

This study used a hybrid near-infrared diffuse optical instrument to monitor tumor hemodynamic responses to chemoradiation therapy for early prediction of treatment outcomes in patients with head and neck cancer. Forty-seven patients were measured once per week to evaluate the hemodynamic status of clinically involved cervical lymph nodes as surrogates for the primary tumor response. Patients were classified into two groups: complete response (CR) (n = 29) and incomplete response (IR) (n = 18). Tumor hemodynamic responses were found to be associated with clinical outcomes (CR/IR), wherein the associations differed depending on human papillomavirus (HPV-16) status. In HPV-16 …

Baby, This World Is Cruel, Nytesia S. Ross

Journal of Multicultural Affairs

This poem is about a woman's fear of bringing a child into this world.

Left And Right Ventricular Dyssynchrony And Strains From Cardiovascular Magnetic Resonance Feature Tracking Do Not Predict Deterioration Of Ventricular Function In Patients With Repaired Tetralogy Of Fallot, Linyuan Jing, Gregory J. Wehner, Jonathan D. Suever, Richard Charnigo, Sudad Alhadad, Evan Stearns, Dimitri Mojsejenko, Christopher M. Haggerty, Kelsey Hickey, Anne Marie Valente, Tal Geva, Andrew J. Powell, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Background: Patients with repaired tetralogy of Fallot (rTOF) suffer from progressive ventricular dysfunction decades after their surgical repair. We hypothesized that measures of ventricular strain and dyssynchrony would predict deterioration of ventricular function in patients with rTOF.

Methods: A database search identified all patients at a single institution with rTOF who underwent cardiovascular magnetic resonance (CMR) at least twice, > 6 months apart, without intervening surgical or catheter procedures. Seven primary predictors were derived from the first CMR using a custom feature tracking algorithm: left (LV), right (RV) and inter-ventricular dyssynchrony, LV and RV peak global circumferential strains, and LV and …

Stability And Kinetics Of Dna Pseudoknots: Formation Of T∗A•T Base-Triplets And Their Targeting Reactions, Calliste Steffensmeier

Theses & Dissertations

Pseudoknots have been found to play important roles in the biology of RNA. These stem-loop motifs are considered to be very compact and the targeting of their loops with complementary strands is accompanied with lower favorable free energy terms. We used a combination of spectroscopic (UV, CD and fluorescence), calorimetric (DSC, PPC and ITC) and kinetic (SPR) techniques to investigate: 1) Local base-triplet formation in pseudoknots; 2) energetic contributions for the association of pseudoknots with their complementary strands; and 3) the kinetic rates as a function of targeting strand length.

We investigated a set of DNA pseudoknots with sequence: d(TCTCT …

Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos

Dissertations and Theses

The tunneling fold (T-Fold) superfamily is a small superfamily of enzymes found in organisms encompassing all kingdoms of life. Seven members have been identified thus far. Despite sharing a common three-dimensional structure these enzymes perform very diverse chemistries.

QueF is a bacterial NADPH-dependent oxidoreductase that catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ₀) to a primary amine (preQ₁) in the queuosine biosynthetic pathway. Previous work on this enzyme has revealed the mechanism of reaction but the cofactor binding residues remain unknown. The experiments discussed herein aim to elucidate the role of residues lysine 80, …

Inhibiting Androgen Receptor Nuclear Entry In Castration-Resistant Prostate Cancer, Julie A. Pollock, Suzanne E. Wardell, Alexander A. Parent, David B. Stagg, Stephanie J. Ellison, Holly M. Alley, Christina A. Chao, Scott A. Lawrence, James P. Stice, Ivan Spasojevic, Jennifer G. Baker, Sung Hoon Kim, Donald P. Mcdonnell, John A. Katzenellenbogen, John D. Norris

Chemistry Faculty Publications

Clinical resistance to the second-generation antiandrogen enzalutamide in castration resistant prostate cancer (CRPC), despite persistent androgen receptor (AR) activity in tumors, highlights the unmet medical need for next generation antagonists. We have identified and characterized tetra-aryl cyclobutanes (CBs) as a new class of competitive AR antagonists that exhibit a unique mechanism of action. These CBs are structurally distinct from current antiandrogens (hydroxyflutamide, bicalutamide, and enzalutamide), and inhibit AR-mediated gene expression, cell proliferation, and tumor growth in several models of CRPC. Conformational profiling revealed that CBs stabilize an AR conformation resembling an unliganded receptor. Using a variety of techniques, it was …

Analyzing Sports Training Data With Machine Learning Techniques, Rehana Mahfuz, Zeinab Mourad, Aly El Gamal

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the sports industry, there has not been enough effort in analyzing the personalized monitoring data of athletes collected during training sessions. This research is an attempt to find meaningful patterns in the Purdue Women’s Soccer training data that could help the coach design more efficient training sessions. We are specifically interested in studying this problem as an unsupervised learning problem. Our initial attempt is to cluster the players as well as drills into groups using k-means, c-means and spectral clustering algorithms, combined with feature transformation and reduction steps. These basic algorithms serve as a benchmark to measure performance improvements …

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …

The Impact Of Patient Navigation On The Delivery Of Diagnostic Breast Cancer Care In The National Patient Navigation Research Program: A Prospective Meta-Analysis., Tracy A Battaglia, Julie S Darnell, Naomi Ko, Fred Snyder, Electra D Paskett, Kristen J Wells, Elizabeth M Whitley, Jennifer J Griggs, Anand Karnad, Heather Young, Victoria Warren-Mears, Melissa A Simon, Elizabeth Calhoun

Epidemiology Faculty Publications

Patient navigation is emerging as a standard in breast cancer care delivery, yet multi-site data on the impact of navigation at reducing delays along the continuum of care are lacking. The purpose of this study was to determine the effect of navigation on reaching diagnostic resolution at specific time points after an abnormal breast cancer screening test among a national sample. A prospective meta-analysis estimated the adjusted odds of achieving timely diagnostic resolution at 60, 180, and 365 days. Exploratory analyses were conducted on the pooled sample to identify which groups had the most benefit from navigation. Clinics from six …

Multipurpose Tenofovir Disoproxil Fumarate Electrospun Fibers For The Prevention Of Hiv-1 And Hsv-2 Infections., Kevin Tyo

Electronic Theses and Dissertations

Sexually transmitted infections affect hundreds of millions of worldwide. Both human immunodeficiency virus (HIV-1 and -2) and herpes simplex virus-2 (HSV-2) remain incurable, urging the development of new prevention strategies. While current prophylactic technologies are dependent on strict user adherence to achieve efficacy, there is a dearth of delivery vehicles that provide discreet and convenient administration, combined with prolonged-delivery of active agents. To address these needs, we created electrospun fibers (EFs) comprised of FDA-approved polymers, poly(lactic-co-glycolic acid) (PLGA) and poly(DL-lactide-co-ε-caprolactone) (PLCL), to provide sustained-release and in vitro protection against HIV-1 and HSV-2. PLGA and PLCL EFs, incorporating the antiretroviral, tenofovir …

Manufacturer Perspectives On Content Transparency And Material Health In The Us Building Products Industry, Alexandra A. Muller

Open Access Theses

Flawed U.S. federal regulation of chemicals has resulted in a materials market that undervalues human and environmental health in favor of the more traditional attributes of price, performance and aesthetics. In the building products industry, global, dynamic supply chains and proprietary information concerns further complicate the task of assessing the material health of products.

Voluntary material health programs in the green building industry are intended to incentivize the manufacture and selection of safer products by getting companies to gather and assess ingredient, hazard and risk information from their supply chain. Building product manufacturers considered early adopters of the main material …

A Dose Distribution Study Of Uranyl Nitrate In Zebrafish Using Liquid Scintillation And Passivated Implanted Planar Silicon Detectors, Lee A. Alleman

Open Access Theses

Standard curves for a Perkin Elmer TriCarb 2800 liquid scintillation detector (LSC) and a Ludlum 3030p Passivated Implanted Planar Silicon detector have been developed and utilized for studying the dose distribution of depleted uranium (DU) within zebrafish. The DU source was crystallized uranyl nitrate (N2O8U•6H2O) solution, normally used for staining in electron microscopy with a manufactured average specific activity of 0.3 uCi/g. Zebrafish, both larvae and adults, were exposed to three different mass concentrations, dissected, dissolved and counted using an LSC. The counts were compared to the standard curve correlating the measured activity to that of the mass absorbed. It …

Measurement Of Neutron Activation From A High Energy Varian Linear Accelerator, Timothy Thatcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation from a Varian medical linear accelerator at energies above 10 MeV. A Varian 21iX accelerator was used to irradiate a 30 cm x 30 cm x 20 cm …

Identifying Treatment Planning System Errors In Iroc-Houston Head And Neck Phantom Irradiations, James Kerns

Dissertations and Theses (Open Access)

Treatment Planning System (TPS) errors can affect large numbers of cancer patients receiving radiation therapy. Using an independent recalculation system, the Imaging and Radiation Oncology Core-Houston (IROC-H) can identify institutions that have not sufficiently modelled their linear accelerators in their TPS model. Linear accelerator point measurement data from IROC-H’s site visits was aggregated and analyzed from over 30 linear accelerator models. Dosimetrically similar models were combined to create “classes”. The class data was used to construct customized beam models in an independent treatment dose verification system (TVS). Approximately 200 head and neck phantom plans from 2012 to 2015 were recalculated …

Diabetes Is Associated With Cerebrovascular But Not Alzheimer's Disease Neuropathology, Erin L. Abner, Peter T. Nelson, Richard J. Kryscio, Frederick A. Schmitt, David W. Fardo, Randall L. Woltjer, Nigel J. Cairns, Lei Yu, Hiroko H. Dodge, Chengjie Xiong, Kamal Masaki, Suzanne L. Tyas, David A. Bennett, Julie A. Schneider, Zoe Arvanitakis

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: The relationship of diabetes to specific neuropathologic causes of dementia is incompletely understood.

METHODS: We used logistic regression to evaluate the association between diabetes and infarcts, Braak neurofibrillary tangle stage, and neuritic plaque score in 2365 autopsied persons. In a subset of >1300 persons with available cognitive data, we examined the association between diabetes and cognition using Poisson regression.

RESULTS: Diabetes increased odds of brain infarcts (odds ratio [OR] = 1.57, P < .0001), specifically lacunes (OR = 1.71, P < .0001), but not Alzheimer's disease neuropathology. Diabetes plus infarcts was associated with lower cognitive scores at end of life than infarcts or diabetes alone, and diabetes plus high level of Alzheimer's neuropathologic changes was associated with lower mini-mental state examination scores than the pathology alone.

DISCUSSION: This study supports the conclusions that diabetes increases the risk of cerebrovascular but not Alzheimer's disease pathology, and at least some of diabetes' relationship to …

Analysis Of The Intricacies Of Substrate Recognition Of High Mobility Group Proteins And Aminoacyl-Trna Synthetases Using Non-Cognate Substrates, Douglas Van Iverson Ii

Dissertations

The studies presented in section 1 (Chapters I-IV) focus on the design and development of nucleic acid four-way junctions (4WJs) to target a member of the high mobility group (HMG) proteins, the proinflammatory cytokine high mobility group box 1 protein (HMGB1). In the present study, hybrid PNA-DNA 4WJs based on a model DNA 4WJ were constructed to improve the thermal stability of 4WJs while maintaining strong binding affinity toward HMGB1. An electrophoretic mobility shift assay (EMSA) was used to examine the binding affinity of an isolated DNA binding domain of HMGB1, the HMGB1 b-box (HMGB1b), toward a set of PNA-DNA …

An Automated Syringe Pump System For Improving The Reproducibility Of Dynamic Hyperpolarized Mri Phantoms, Harlee G. Harrison

Dissertations and Theses (Open Access)

AN AUTOMATED SYRINGE PUMP SYSTEM FOR IMPROVING THE REPRODUCIBILITY OF DYNAMIC HYPERPOLARIZED MRI PHANTOMS

Harlee Grace Harrison, B.S.

Advisory Professor: James Bankson, Ph.D.

Magnetic Resonance Imaging (MRI) is a powerful tool in the diagnosis of cancer due to its ability to provide good soft tissue contrast and image resolution without the use of ionizing radiation. The use of hyperpolarized pyruvate as a contrast agent for tumor metabolism during MR scans has the potential to provide information about tumor metabolism in vivo that is not available from traditional imaging measurements or any other method. Hyperpolarization is achieved through dynamic nuclear polarization. …

Measurement Of The Electron Return Effect Using Presage Dosimeter, Gye Won Choi

Dissertations and Theses (Open Access)

MR-guided radiation therapy (MRgRT) provides benefits such as superior soft tissue contrast, no imaging dose, and functional imaging capacities, but it also has concerns to be addressed. The electron return effect (ERE) refers to dose enhancement at the interface between different media, caused when radiation is delivered in the magnetic field. The ERE poses clinical concerns in MRgRT because it significantly enhances the dose at interfaces, and the intensity and pattern of the dose enhancement depends on many factors. The ERE results in a complex pattern of dose enhancement over a three-dimensional (3D) volume around tissue interfaces inside the patient …