Showing papers by "Dat Q. Tran published in 2021"

The Association of Gut Microbiota and Treg Dysfunction in Autoimmune Diseases.

Abstract: Autoimmune conditions affect 23 million Americans or 7% of the US population. There are more than 100 autoimmune disorders, affecting every major organ system in humans. This chapter aims to further explain Treg dysfunction autoimmune disorders, including monogenic primary immune deficiency such as immune dysregulation polyendocrinopathy, enteropathy, X-linked inheritance (IPEX) syndrome, and polygenic autoimmune diseases with Treg dysfunction such as multiple sclerosis (MS), inflammatory bowel disease (IBD), and food allergy. These conditions are associated with an abnormal small intestinal and colonic microbiome. Some disorders clearly improve with therapies aimed at microbial modification, including probiotics and fecal microbiota transplantation (FMT). Approaches to prevent and treat these disorders will need to focus on the acquisition and maintenance of a healthy colonic microbiota, in addition to more focused approaches at immune suppression during acute disease exacerbations.

Treg-associated monogenic autoimmune disorders and gut microbial dysbiosis.

Abstract: Primary immunodeficiency diseases (PIDs) caused by a single-gene defect generally are referred to as monogenic autoimmune disorders. For example, mutations in the transcription factor autoimmune regulator (AIRE) result in a condition called autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy; while mutations in forkhead box P3 lead to regulatory T cell (Treg)-deficiency-induced multiorgan inflammation, which in humans is called "immune dysregulation, polyendocrinopathy, enteropathy with X-linked inheritance" (or IPEX syndrome). Previous studies concluded that monogenic diseases are insensitive to commensal microbial regulation because they develop even in germ-free (GF) animals, a conclusion that has limited the number of studies determining the role of microbiota in monogenic PIDs. However, emerging evidence shows that although the onset of the disease is independent of the microbiota, several monogenic PIDs vary in severity in association with the microbiome. In this review, we focus on monogenic PIDs associated with Treg deficiency/dysfunction, summarizing the gut microbial dysbiosis that has been shown to be linked to these diseases. From limited studies, we have gleaned several mechanistic insights that may prove to be of therapeutic importance in the early stages of life. IMPACT: This review paper serves to refute the concept that monogenic PIDs are not linked to the microbiome. The onset of monogenic PIDs is independent of microbiota; single-gene mutations such as AIRE or Foxp3 that affect central or peripheral immune tolerance produce monogenic diseases even in a GF environment. However, the severity and outcome of PIDs are markedly impacted by the microbial composition. We suggest that future research for these conditions may focus on targeting the microbiome.

Parallel computation of CRC-code on an FPGA

Abstract: With the rapid advancement of imaging technology, space-based remote sensing instruments are becoming more sophisticated and are producing substantially more amounts of data for downloading. Data alteration is very likely to occur during the transmission over the long distances from probes to carrier spacecraft and subsequently back to Earth,. Cyclic Redundancy Check (CRC) is the most well-known data package error check technique which has been used in many applications. Unfortunately, due to its serial computation process, it could be a bottleneck for critical applications that require rapid processing. To overcome such issue, we present here a parallel CRC computational method based on an FPGA with simulation and testing to validate the methodology.

Parallel Computation of CRC-Code on an FPGA Platform for High Data Throughput

Abstract: With the rapid advancement of radiation hard imaging technology, space-based remote sensing instruments are becoming not only more sophisticated but are also generating substantially more amounts of data for rapid processing. For applications that rely on data transmitted from a planetary probe to a relay spacecraft to Earth, alteration or discontinuity in data over a long transmission distance is likely to happen. Cyclic Redundancy Check (CRC) is one of the most well-known package error check techniques in sensor networks for critical applications. However, serial CRC computation could be a bottleneck of the throughput in such systems. In this work, we design, implement, and validate an efficient hybrid look-up-table and matrix transformation algorithm for high throughput parallel computational unit to speed-up the process of CRC computation using both CPU and Field Programmable Gate Array (FPGA) with comparison of both methods.

High resolution gas mid-infrared spectroscopy using circular multi-reflection (CMR) cell

Abstract: Mid-infrared (IR) laser spectroscopy is broadly used to study trace gas species in medical diagnostics, atmospheric monitoring, remote sensing, and industrial applications. Its capability to measure fundamental rovibrational bands due to the chemical functional groups in the most relevant gas molecules allows for high instrumental sensitivity. In this work, we used a target mid-IR wavelength laser diode to measure the concentration of CO2 gas. In addition, detecting the weak mid-IR molecular absorption bands of gases like CO2 at low concentrations requires increasing optical path lengths to be used. There are a number of methods that can potentially be used to lengthen the beam path in a spectroscopic system; the most obvious being to use a longer linear gas cell, which in some situations may suffice; however, space and volume requirements need to be considered. In this work, we used a circular multi-reflection (CMR) cell, which reflects the radiation back and forth through the sample medium multiple times greatly reducing the footprint size compared to a linear cell of equivalent path length. A CMR cell is designed and constructed so that it allows multi-reflections within the cell. The optical alignment of the cell and the convenience of changing the optical path length by adjusting its position with respect to the entering light beam are key advantages. This work will be used as the groundwork for designing an instrument for high-resolution measurement of gas abundances in planetary atmospheres.