988 research outputs found
Layered Metals Fabrication Technology Development for Support of Lunar Exploration at NASA/MSFC
NASA's human exploration initiative poses great opportunity and risk for missions to the Moon and beyond. In support of these missions, engineers and scientists at the Marshall Space Flight Center are developing technologies for ground-based and in-situ fabrication capabilities utilizing provisioned and locally-refined materials. Development efforts are pushing state-of-the art fabrication technologies to support habitat structure development, tools and mechanical part fabrication, as well as repair and replacement of ground support and space mission hardware such as life support items, launch vehicle components and crew exercise equipment. This paper addresses current fabrication technologies relative to meeting targeted capabilities, near term advancement goals, and process certification of fabrication methods
Control system for thermoelectric refrigerator
Apparatus including a power supply (202) and control system is provided for maintaining the temperature within an enclosed structure (40) using thermoelectric devices (92). The apparatus may be particularly beneficial for use with a refrigerator (20) having superinsulation materials (46) and phase change materials (112) which cooperate with the thermoelectric device (92) to substantially enhance the overall operating efficiency of the refrigerator (20). The electrical power supply (202) and control system allows increasing the maximum power capability of the thermoelectric device (92) in response to increased heat loads within the refrigerator (20). The electrical power supply (202) and control system may also be used to monitor the performance of the cooling system (70) associated with the refrigerator (20)
From Lunar Regolith to Fabricated Parts: Technology Developments and the Utilization of Moon Dirt
The U.S. Space Exploration Policy has as a cornerstone the establishment of an outpost on the moon. This lunar outpost wil1 eventually provide the necessary planning, technology development, testbed, and training for manned missions in the future beyond the Moon. As part of the overall activity, the National Aeronautics and Space Administration (NASA) is investigating how the in situ resources can be utilized to improve mission success by reducing up-mass, improving safety, reducing risk, and bringing down costs for the overall mission. Marshall Space Flight Center (MSFC), along with other NASA centers, is supporting this endeavor by exploring how lunar regolith can be mined for uses such as construction, life support, propulsion, power, and fabrication. An infrastructure capable of fabrication and nondestructive evaluation will be needed to support habitat structure development and maintenance, tools and mechanical parts fabrication, as well as repair and replacement of space-mission hardware such as life-support items, vehicle components, and crew systems, This infrastructure will utilize the technologies being developed under the In Situ Fabrication and Repair (ISFR) element, which is working in conjunction with the technologies being developed under the In Situ Resources Utilization (ISRU) element, to live off the land. The ISFR Element supports the Space Exploration Initiative by reducing downtime due to failed components; decreasing risk to crew by recovering quickly from degraded operation of equipment; improving system functionality with advanced geometry capabilities; and enhancing mission safety by reducing assembly part counts of original designs where possible. This paper addresses the need and plan for understanding the properties of the lunar regolith to determine the applicability of using this material in a fabrication process. This effort includes the development of high fidelity simulants that will be used in fabrication processes on the ground to drive down risk and increase the Technology Readiness Level (TRL) prior to implementing this capability on the moon. Also discussed in this paper is the on-going research using Electron Beam Melting (EBM) technology as a possible solution to manufacturing parts and spares on the Moon's surface
Crowding Promotes the Switch from Hairpin to Pseudoknot Conformation in Human Telomerase RNA
Formation of a pseudoknot in the conserved RNA core domain in the
ribonucleoprotein human telomerase is required for function. In vitro
experiments show that the pseudoknot (PK) is in equilibrium with an extended
hairpin (HP) structure. We use molecular simulations of a coarse-grained model,
which reproduces most of the salient features of the experimental melting
profiles of PK and HP, to show that crowding enhances the stability of PK
relative to HP in the wild type and in a mutant associated with dyskeratosis
congenita. In monodisperse suspensions, small crowding particles increase the
stability of compact structures to a greater extent than larger crowders. If
the sizes of crowders in a binary mixture are smaller than the unfolded RNA,
the increase in melting temperature due to the two components is additive. In a
ternary mixture of crowders that are larger than the unfolded RNA, which mimics
the composition of ribosome, large enzyme complexes and proteins in E. coli,
the marginal increase in stability is entirely determined by the smallest
component. We predict that crowding can restore partially telomerase activity
in mutants, which dramatically decrease the PK stability.Comment: File "JACS_MAIN_archive_PDF_from_DOC.pdf" (PDF created from DOC)
contains the main text of the paper File JACS_SI_archive.tex + 7 figures are
the supplementary inf
Thermoelectric refrigerator
A refrigerator is provided which combines the benefits of superinsulation materials with thermoelectric devices and phase change materials to provide an environmentally benign system that is energy efficient and can maintain relatively uniform temperatures for extended periods of time with relatively low electrical power requirements. The refrigerator includes a thermoelectric assembly having a thermoelectric device with a hot sink and a cold sink. The superinsulation materials include a plurality of vacuum panels. The refrigerator is formed from an enclosed structure having a door. The vacuum panels may be contained within the walls of the enclosed structure and the door. By mounting the thermoelectric assembly on the door, the manufacturer of the enclosed structure is simplified and the overall R rating of the refrigerator increased. Also an electrical motor and propellers may be mounted on the door to assist in the circulation of air to improve the efficiency of the cold sink and the hot sink. A propeller and/or impeller is preferably mounted within the refrigerator to assist in establishing the desired air circulation flow path
NF-κB-dependent and -independent epigenetic modulation using the novel anti-cancer agent DMAPT
The transcription factor nuclear factor-kappaB (NF-κB) is constitutively active in several cancers and is a target of therapeutic development. We recently developed dimethylaminoparthenolide (DMAPT), a clinical grade water-soluble analog of parthenolide, as a potent inhibitor of NF-κB and demonstrated in vitro and in vivo anti-tumor activities in multiple cancers. In this study, we show DMAPT is an epigenetic modulator functioning in an NF-κB-dependent and -independent manner. DMAPT-mediated NF-κB inhibition resulted in elevated histone H3K36 trimethylation (H3K36me3), which could be recapitulated through genetic ablation of the p65 subunit of NF-κB or inhibitor-of-kappaB alpha super-repressor overexpression. DMAPT treatment and p65 ablation increased the levels of H3K36 trimethylases NSD1 (KMT3B) and SETD2 (KMT3A), suggesting that NF-κB directly represses their expression and that lower H3K36me3 is an epigenetic marker of constitutive NF-κB activity. Overexpression of a constitutively active p65 subunit of NF-κB reduced NSD1 and H3K36me3 levels. NSD1 is essential for DMAPT-induced expression of pro-apoptotic BIM, indicating a functional link between epigenetic modification and gene expression. Interestingly, we observed enhanced H4K20 trimethylation and induction of H4K20 trimethylase KMT5C in DMAPT-treated cells independent of NF-κB inhibition. These results add KMT5C to the list NF-κB-independent epigenetic targets of parthenolide, which include previously described histone deacetylase 1 (HDAC-1) and DNA methyltransferase 1. As NSD1 and SETD2 are known tumor suppressors and loss of H4K20 trimethylation is an early event in cancer progression, which contributes to genomic instability, we propose DMAPT as a potent pharmacologic agent that can reverse NF-κB-dependent and -independent cancer-specific epigenetic abnormalities
THE INDIANA CENTER FOR BREAST CANCER RESEARCH: PROGRESS REPORT
poster abstractThe mission of IUPUI breast cancer center is to address prevention, early detection, and treatment of breast cancer through translational projects, supportive cores, and synergistic programs. This poster details our efforts improve resources for breast cancer research and efforts to develop multi-PI investigator proposals. The Signature Center Initiative has developed two web resources: the Breast Cancer Prognostics Database (BCDB) to study prognostic implications of genes of interest in publically available breast cancer databases and PROGmiR, a microRNA database. The BCDB can be used to study overall, recurrence free and metastasis free survival in large patient series. PROGmiR allows investigators to study the prognostic importance of microRNAs. PROGmiR has recently been published and has been accessed by investigators from several countries. The signature center has also devoted considerable efforts in developing tumor tissue resource. Tissue Bank includes a total sample of N = 500 cases with 30% non-Caucasian cases from Wishard Memorial Hospital. Currently 237 cases have been assembled into a Tissue Microarray with clinical and follow up data. The breast cancer center has funded three pilot projects. Drs. Clark Wells, S. Badve, and G. Sandusky are collaborating on the project: “Histologic Analysis of the Protein Levels of Amot130, AmotL1 and YAP in Normal, Hyperplastic and Invasive Breast Cancer Tissues”. This project is investigating localized protein expression in paraffin-embedded tissues to associate expression levels with disease subtype and patient outcome. Dr. David Gilley and his group are collaborating on the project: “Luminal mammary progenitors are a unique site of telomere dysfunction”. This project is investigating the relationship between telomere dysfunction and breast cancer tumorigenesis. In the third project, Dr. Theresa Guise will be investigating the mechanisms of cancer-associated cachexia. Several multi-PI proposals are under preparation and one proposal with Drs. Nakshatri and Kathy Miller as PIs is currently under review
Snow load modelling for structural load combination methods
New methods of load combination analysis have been developed that describe more accurately the combined loads acting on structures. Present design codes using probability- based load factors have not evolved to the use of these new methods due to a lack of statistical data needed to describe the various load types.
Statistics of water equivalent ground snow load data were obtained for seventeen sites across the United States. These snow loads were modeled as a Poisson square wave pulse process. Daily water equivalent snow load intensity was fitted with a Weibull distribution. Verification of this distribution function was provided by comparison of predicted 50-year snow loads to well established 50-year snow loads.
Occurrence dependence, intensity and duration dependence, and intensity dependence were considered with respect to their effect on load combination analyses. The correlation of snow loads with other loads was also considered
Sustainable Human Presence on the Moon using In Situ Resources
New capabilities, technologies and infrastructure must be developed to enable a sustained human presence on the moon and beyond. The key to having this permanent presence is the utilization of in situ resources. To this end, NASA is investigating how in situ resources can be utilized to improve mission success by reducing up-mass, improving safety, reducing risk, and bringing down costs for the overall mission. To ensure that this capability is available when needed, technology development is required now. NASA/Marshall Space Flight Center (MSFC) is supporting this endeavor, along with other NASA centers, by exploring how lunar regolith can be mined for uses such as construction, life support, propulsion, power, and fabrication. Efforts at MSFC include development of lunar regolith simulant for hardware testing and development, extraction of oxygen and other materials from the lunar regolith, production of parts and tools on the moon from local materials or from provisioned feedstocks, and capabilities to show that produced parts are "ready for use". This paper discusses the lunar regolith, how the regolith is being replicated in the development of simulants and possible uses of the regolith
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