Denton, TX, United States

University of North Texas
Denton, TX, United States

The University of North Texas , based in Denton, is a public institution of higher education and research committed to a wide array of science, engineering fields, liberal arts, fine arts, performing arts, humanities, public policy, and graduate professional education. Ten colleges, two schools, an early admissions math and science academy for exceptional high-school-age students from across the state, and a library system comprise the university. Its research is driven by about 34 doctoral degree programs. During the 2013–2014 school year, the university had a budget of $865 million, of which $40 million was allocated for research. North Texas was founded as a nonsectarian, coeducational, private teachers college in 1890; and, as a collaborative development in response to enrollment growth and public demand, its trustees ceded control to the state in 1899. In 1901, North Texas was formally adopted by the State. Wikipedia.

Time filter

Source Type

University of North Texas | Date: 2016-10-26

Therapeutic particles contain metal ions and are characterized by the use of unique ligand sets capable of making the metal ion complex soluble in biological media to induce selective toxicity in diseased cells. The particles may comprise a polymeric base particle, at least one pharmaceutically active metal ion, including metal ions from more than one metal element, a ligand that is covalently attached to the polymeric base particle and attached to the metal ion via a stimuli-responsive bond, and a cell targeting component. When the metal ion-containing particle enters a pre-defined environment, the ligands binding the metal to the particle are broken, triggering release of the free metal ion while the original ligands remain covalently bound to the particle.

University of North Texas | Date: 2016-11-30

Size-tunable phosphorescent particles may be formed through self-assembly of biocompatible linear polymers, such as chitosan and other linear polymers, that bear positive surface charges, through polyelectrolytic complexation to a polyanionic metal phosphor, such as polyanionic gold(I) phosphor (AuP). The phosphorescent hydrogel nanoparticles and thin films thereof are useful for imaging, sensing of biological molecules, detection of hypoxia, and light-emitting devices. The phosphorescent hydrogel particles can be formed from a variety of linear polymers by physical cross-linking using polyelectrolytic light-emitting species, without the need for the phosphorescent complex to be entrapped in an existing microsphere or nanosphere polymer particle.

The present invention provides amorphous bi-functional catalytic aluminum metallic glass particles having an aluminum metallic glass core and 2 or more transition metals disposed on the surface of the aluminum metallic glass core to form amorphous bi-functional aluminum metallic glass particles with catalytic activity.

Ayre B.G.,University of North Texas
Molecular Plant | Year: 2011

Sucrose is the principal product of photosynthesis used for the distribution of assimilated carbon in plants. Transport mechanisms and efficiency influence photosynthetic productivity by relieving product inhibition and contribute to plant vigor by controlling source/sink relationships and biomass partitioning. Sucrose is synthesized in the cytoplasm and may move cell to cell through plasmodesmata or may cross membranes to be compartmentalized or exported to the apoplasm for uptake into adjacent cells. As a relatively large polar compound, sucrose requires proteins to facilitate efficient membrane transport. Transport across the tonoplast by facilitated diffusion, antiport with protons, and symport with protons have been proposed; for transport across plasma membranes, symport with protons and a mechanism resembling facilitated diffusion are evident. Despite decades of research, only symport with protons is well established at the molecular level. This review aims to integrate recent and older studies on sucrose flux across membranes with principles of whole-plant carbon partitioning. © 2011 The Author.

D'Souza F.,University of North Texas | Ito O.,Japan Science and Technology Agency
Chemical Society Reviews | Year: 2012

Photosensitized electron-transfer processes of nanocarbon materials hybridized with electron donating or electron accepting molecules have been surveyed in this tutorial review on the basis of the recent results reported mainly from our laboratories. As nano-carbon materials, fullerenes and single wall carbon nanotubes (SWCNTs) have been employed. Fullerenes act as photo-sensitizing electron acceptors with respect to a wide variety of electron donors; in addition, the fullerenes act as good ground state electron acceptors in the presence of light-absorbing electron donors such as porphyrins and phthalocyanines. In the case of SWCNTs, their ground states act as electron acceptor and electron donors, depending on the photosensitizers. For example, with respect to the photoexcited porphyrins and phthalocyanines, SWCNTs usually act as electron acceptors, whereas for the photoexcited fullerenes, SWCNTs act as electron donors. The diameter sorted semi-conductive SWCNTs have been used to verify the size-dependent electron transfer rates. For the confirmation of the electron transfer processes, the transient absorption methods have been widely used, in addition to the time-resolved fluorescence spectral measurements. The kinetic data thus obtained in solution are found to be quite useful to predict the efficiencies of photovoltaic cells constructed on semiconductor nanoparticle modified electrodes and their photocatalytic processes.

Agency: NSF | Branch: Standard Grant | Program: | Phase: Physiolg Mechansms&Biomechancs | Award Amount: 564.32K | Year: 2016

Increasing crop productivity while reducing environmental impacts of agriculture are prominent challenges. Phosphate is an essential nutrient, but is also a major component of agricultural runoff and water pollution. Increased photosynthesis and transport of sugars from leaves to growing organs was hypothesized to increase overall growth, but new evidence argues that this creates an imbalance in the ratio of photoassimilated carbon (the sugars produced by photosynthesis) and available phosphate, and causes stunting. More phosphate restores growth, but also contributes to more runoff. The implication is that efforts to improve photosynthesis and growth while simultaneously reducing phosphate requirements may be imperiled unless the interaction between carbon and phosphate is understood and uncoupled. This proposal aims to differentiate between two possibilities. 1) The carbon/phosphate interaction is predominantly a biochemical limitation: more carbon in growing tissues triggers a need for more phosphate-containing metabolites. 2) The plant measures the carbon/phosphate balance, and excessive carbon is recognized as a phosphate deficiency even though none exists. These will be tested through physiological, genetic, and metabolic experiments to learn if the links between carbon transport and phosphate needs can be uncoupled. This work will reveal strategies that can be used to increase productivity while reducing fertilizer needs. In addition to traditional training of students in the research laboratory, broader undergraduate participation will be achieved by incorporating some aspects of the project into the upper level Plant Physiology laboratory undergraduate course. The approximately 30 students who take the course each year will learn principles of genetics, molecular biology, and bioinformatics. This will not only give hands-on biotechnology experience in an active-learning environment, but also will be used as an opportunity to explore the Genetically Modified Organisms GMO debate with a group of undergraduates who might otherwise be unlikely to engage with this important societal issue.

Enhanced sucrose transport from source leaves to sink organs should improve crop yields by providing more resources for growth while relieving product inhibition on photosynthesis. Over-expressing sucrose transporters (SUTs) in the phloem enhances transport but causes stunted growth originating from a perceived phosphorus (P) deficiency: P-starvation genes are up-regulated and the effect is reversed by P supplementation. P is a non-renewable essential element and a component of agricultural runoff, such that reducing P requirements while maintaining yields are also prominent challenges. One possibility is that more sucrose causes stunting by sequestering too much P in metabolic intermediates. Another possibility is that signaling between carbon (C) and P provokes preparation for P-limitation. These will be tested through experiments that include 1) growth with phosphite as a phosphate analog to separate signaling and biochemical effects; 2) reverse and forward genetics to identify genes that modulate C:P interaction; 3) transcriptomics to capture gene-expression reprioritization during Suc-induced P-limitations; 4) metabolic analyses to capture metabolome remodeling during Suc-induced P-limitations; and 5) physiological experiments with gain and loss of function lines to learn if C:P links can be uncoupled.

Agency: NSF | Branch: Continuing grant | Program: | Phase: Physiolg Mechansms&Biomechancs | Award Amount: 632.00K | Year: 2016

Biological processes such as responses to stress, cell death and lifespan depend on maintaining a balance among levels of various compounds such as fats (lipids), iron and sugars. Although substantial research efforts have revealed how the levels of fats and sugars are controlled by different hormones, such as insulin, the connection of these processes to processes that regulate iron levels is poorly understood. Recently, the investigators identified cellular processes that potentially integrate the ways that iron and lipid levels are maintained. The investigators will determine the dynamics and interaction between iron homeostasis and synthesis of specific lipids (ceramides), and how these interactions impact organismal functions such as metabolism, cell death and responses to stress. A genetic model system will be used to identify novel genes involved with cellular iron and lipid homeostasis. Additionally, the investigators will incorporate their research with education by providing research opportunities and mentoring to graduate and undergraduate students. Furthermore, an outreach-based learning module will be incorporated into the existing and successful UNT Elm Fork Education Center. This science education center reaches over 20,000 visitors per year (majority are K-8th graders). By collaborating with the Elm Fork Education Center students will be exposed to the field of genetic modeling and the cellular responses to environmental stress in animals. Completion of this project will elucidate novel mechanisms regulating mitochondrial function relative to whole animal biology.

The goals of this project are to dissect the pathways controlling sphingolipid/ceramide metabolism and iron regulation and to determine if sphingolipid/ceramide metabolism and iron regulation are mechanistically linked. The approach is to use the genetic model system Caenorhabditis elegans to conduct cellular, molecular and genetic analysis on mutants with altered sphingolipid/ceramide metabolism and iron regulation. The investigators will test the hypothesis that 1) central features of mitochondrial function and the response to oxygen deprivation in an intact whole organism are sphingolipid/ceramide metabolism and iron regulation; and 2) sphingolipid/ceramide metabolism and iron regulation are mechanistically linked in mitochondrial functions. To test these hypothesis the following Specific Aims will be conducted: Aim 1: Determine how ceramide biosynthesis and iron regulation impact mitochondria functions and whole organism stress responses; Aim 2: Conduct genetic suppression analyses to identify signaling pathways that interact with ceramide biosynthesis and iron regulation; Aim 3. Utilize genetic analysis to determine if neet-1 and ceramide biosynthesis mechanistically interact to regulate mitochondrial functions. The proposed research could have a transformative impact on the way sphingolipid/ceramide metabolism and iron regulation is viewed in the context of mitochondrial homeostasis. The project provides research training for graduate and undergraduate students. Furthermore, an outreach-based learning module that focuses on the genetic model system C. elegans will be offered through a program at the UNT Elm Fork Education center. This outreach program will have a broad impact since it reaches over 20,000 visitors per year.

Agency: NSF | Branch: Standard Grant | Program: | Phase: CRISP - Critical Resilient Int | Award Amount: 270.21K | Year: 2017

Understanding the recovery of communities after disruptions has important implications for efficiently allocating resources, better planning for disasters, and reducing time and cost of recovery. Virtually all communities are embedded in highly interdependent social and physical infrastructure. This coupling between social and physical networks can lead to complex cascading effects that cannot be understood by looking at these networks in isolation. The full implications of these interdependencies for the resilience of communities and their ability to recover after disasters are not currently understood. This research seeks an understanding of the underlying factors that lead to resilience and recovery of interdependent social and physical networks after disasters. The researchers will collect data from communities impacted by Hurricane Sandy to create and test modeling approaches for improved knowledge of both social and physical factors that lead to recovery. It will also lead to a better understanding of the interdependencies between the social and physical systems, and will identify potential tipping points where small changes in the social and physical systems significantly impact the recovery of the overall system. The findings from the study will allow governmental and emergency agencies to take actions that will accelerate system recovery and enhance its resilience. Students and underrepresented groups working on this project will gain exposure and experience working with a multi-disciplinary research team, thereby preparing them for tackling complex, systems-related challenges in their future careers. A workshop will be organized to disseminate the findings to the scientific community and various stakeholders who are involved in recovery processes.

The modeling of resilience in interdependent social and physical networks will be conducted using an interdisciplinary approach. First, the researchers will collect data pertaining to complex interdependencies that influence post-disaster recovery and decision-making. Second, the project will leverage insights gleaned from the data to identify utility functions that influence the decision-making of households, and formulate mathematical techniques based on game theory and network science for modeling and analyzing the tipping points that lead to recovery across social and physical networks. Third, the research effort will create novel state-estimation techniques using publicly available citizen data and develop multi-agent simulation models that will provide new decision-support tools for governmental agencies and emergency response organizations to model, test and predict the effects of recovery actions. The research will identify the role of network structure and function in the movement of the overall system towards better recovery states, and characterize the different events that transpire during community re-entry and recovery processes.

Agency: National Aeronautics and Space Administration | Branch: | Program: STTR | Phase: Phase II | Award Amount: 749.97K | Year: 2016

The gas sensor in the PLSS of the ISS EMU will meet its projected life in 2020, and NASA is planning to replace it. At present, only high TRL devices based on infrared absorption are candidate replacements, because of their proven long-term stability, despite their size and power consumption and failures in the presence of liquid water. No current compact sensor has the tolerance for liquid water that is specifically required for a Portable Life Support Systems (PLSS), and NASA is investigating alternative technologies for the Advanced EMU under development. Intelligent Optical Systems (IOS) will develop a luminescence-based optical sensor probe to monitor carbon dioxide, oxygen, and humidity, and selected trace contaminants. Our monitor will incorporate robust CO2, O2, and H2O partial pressure sensors interrogated with a compact, low-power optoelectronic unit. The sensors not only will tolerate liquid water but will actually operate while wet, and can be remotely connected to electronic circuitry by an optical fiber cable immune to electromagnetic interference. For space systems, these miniature sensor elements with remote optoelectronics give unmatched design flexibility for measurements in highly constrained volume systems such as the space suit. In prior projects IOS has demonstrated a CO2 sensor capable of operating while wet that also met PLSS environmental and analytical requirements. In Phase I, a new generation of CO2 sensors was developed to advance this sensor technology and fully meet all NASA requirements, including sensor life. In Phase II IOS will develop a novel sensor system with unique capabilities for inspired gas monitoring, a unique tool for NASA space suit development. The proposed effort could lead to an alternative to infrared absorption-based devices for space missions. IOS has established collaboration with relevant primes for NASA and the aeronautics and defense industry for technology commercialization.

Agency: NSF | Branch: Standard Grant | Program: | Phase: Systems and Synthetic Biology | Award Amount: 845.39K | Year: 2016

Ever since the introduction of oxygen into the atmosphere by photosynthetic organisms, about 2.7 billion years ago, activated forms of oxygen (called reactive oxygen) have been the unwelcome companions of aerobic life. Although currently used by plant and animal cells as important signaling molecules, these activated forms of oxygen could be highly toxic to cells and tissues and cause oxidative injury (oxidative stress). The long-term goal of this project, led by Ron Mittler and Rajeev Azad of the University of North Texas and Rachel Nechushtai of Hebrew University in Jerusalem, Israel, is to determine how cells monitor their intracellular levels of reactive oxygen and prevent its toxicity. In particular, the project will highlight an unknown aspect of the regulation of reactive oxygen in plant and animal cells, namely the use of iron-sulfur clusters by a newly discovered group of proteins to monitor reactive oxygen levels and regulate cellular metabolism and other vital processes. Results obtained from this study could lead to the development of new and novel approaches to enhance the tolerance of crops to important stresses such as drought and heat or delay senescence. In addition, the proposed study could identify novel plant-based compounds and proteins that mitigate oxidative stress, aging and different diseases such as cancer and diabetes. The PIs will train a number of graduate and undergraduate students and partner with a local education center and museum to provide outreach to K-12 students.

The PIs will investigate the role of a novel class of Fe-S proteins, NEET proteins, in maintaining ROS homeostasis in plant and animal cells. In light of their unique cluster features, it is hypothesized that NEET proteins use their redox-active labile clusters to sense ROS levels in cells and regulate different pathways that alter cellular metabolism. The Specific Aims of the project are: 1. Perform a comparative signaling and regulatory network analysis of plant and animal cells with altered level and/or function of NEET proteins. 2. Identify the NEET interactome network of plant and animal cells. 3. Determine the dynamics of NEET protein localization/ function in cells and conduct genetic complementation studies of NEET proteins between mammalian and plant cells. Using a combination of functional genetics, proteomics, advanced imaging, RNA-Seq and network analysis approaches, a mechanistic understanding of ROS/redox sensing/regulation in cells will be pursued. The mechanisms identified through this proposed NSF-BSF collaboration will be further compared between different kingdoms: plant - studied through the NSF part, and animal - studied through the BSF part of this project, to obtain an evolutionary perspective of ROS/redox sensing/regulation in cells.

This collaborative US/Israel project is supported by the US National Science Foundation and the Israeli Binational Science Foundation.

Loading University of North Texas collaborators
Loading University of North Texas collaborators