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4. Radiation Tolerance Characterization of Dual Band InAs/GaSb Type-II Strain-Layer Superlattice pBp Detectors Using 63 MeV Protons

Author

AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE, Cowan, V M, Morath, C P, Hubbs, J E, Myers, S, Plis, E, Krishna, S, AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE, Cowan, V M, Morath, C P, Hubbs, J E, Myers, S, Plis, E, and Krishna, S

Abstract

The radiation tolerance characterization of dual band InAs/GaSb type-II strain-layer superlattice pBp detectors of varying size using 63 MeV proton irradiation is presented. The detectors' mid-wave infrared performance degraded with increasing proton fluence PhiP up to 3.75 x 10(exp 12)/sq cm or, equivalently, a total ionizing dose=500 kRad (Si). At this PhiP, an 31% drop in quantum efficiency g, 2 order increase in dark current density JD, and consequently, 1 order drop in calculated detectivity D* were observed. Proton damage factors were determined for g and D*. Arrhenius-analysis of temperature-dependent JD measurements reflected significant changes in the activation energies following irradiation., Applied Physics Letters, v101 article 251108, 2012.

Published
2012

10. Bidirectional reflectance distribution function of the Infrared Astronomical Satellite solar-shield material

Author

Hubbs, J. E, Nofziger, M. J, Bartell, F. O, Wolfe, W. L, and Brooks, L. D

Subjects
Optics
Abstract

The Infrared Astronomical Satellite (IRAS) telescope has an outer shield on it which is used to reduce the amount of thermal radiation that enters the telescope. The shield forms the first part of the baffle structure which reduces the photon incidence on the focal plane. It was, therefore, necessary to model this structure for scattering, and a required input for such modeling is the scattering characteristic of this surface. Attention is given to the measurement of the bidirectional reflectance distribution function (BRDF), the reflected radiance divided by the incident irradiance at 10.6 micrometers, 118 micrometers, and at several angles of incidence. Visual observation of the gold sample shows that there are striations which line up in a single direction. The data were, therefore, taken with the sample oriented in each of two directions.

Published
1982

11. Measurements of Martin Black at about 10 microns

Author

Bartell, F. O, Hubbs, J. E, Nofziger, M. J, and Wolfe, W. L

Subjects
Optics
Abstract

The BRDF values of several samples of Martin Black have been measured at 10.6 microns and several angles of incidence. The values are in good agreement with data taken recently on an identical sample with a different instrument and with data from an identical sample taken several years ago with a similar instrument.

Published
1982

12. Scattering characteristics of Martin Black at 118 microns

Author

Brooks, L. D, Hubbs, J. E, Bartell, F. O, and Wolfe, W. L

Subjects
Optics
Abstract

BRDF (bidirectional reflectance distribution function) values for 0.000118 m radiation at different angles of incidence and different scattering angles from the Infrared Astronomical Satellite telescope baffle coated with Martin Black are presented. Data from scatterometer experiments are collected and the BRDF and beta - beta sub 0 (sin theta sub s - sin theta sub 0) values are calculated based on the geometry, the voltage readings, the attenuators in the beam, and the calculated reference levels. A composite curve of forward and backward scattering data for several angles of incidence shows a peak near the specular direction (beta - beta sub 0 = 0), which is the instrument profile reduced by the 20% specular reflection of the Martin Black. The nonspecular part of the reflectivity indicates the slightly specular but largely Lambertian character of the coating. Data for the specular reflectivity as a function of the incidence angle unexpectedly shows a decrease in the specular reflectance with increasing angle of incidence.

Published
1982

29. Scattering Measurements of Raytran Zinc Selenide in Transmission at Wavelengths of 0.6328, 3.39, and 10.6 Micrometers.

Author

ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER, Bartell,F O, DeBell,A G, Dereniak,E L, Hubbs,J, Stuhlinger,T, ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER, Bartell,F O, DeBell,A G, Dereniak,E L, Hubbs,J, and Stuhlinger,T

Abstract

The transmission scattering of three samples of different thicknesses of zinc selenide were measured. The samples were 1/4 in., 3/4 in. and 1 in. thick. Fifty-four plots of the BTDF were made utilizing the scattering data obtained at 0.6328, 3.391, and 10.6 microns. (Author)

Published
1981

38. Spin of Rubidium-81m

Author

Hubbs, J. C., primary, Nierenberg, W. A., additional, Shugart, H. A., additional, and Silsbee, H. B., additional

Published
1956
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46. Total Synthesis of (±)-Isoschizogamine

Author

Hubbs, J. L. and Heathcock, C. H.

Abstract

Isoschizogamine has been prepared for the first time. The synthesis requires eight steps from a readily available ketone starting material and features an aminal-forming cyclization that is based on a proposed biosynthetic transformation.

Published
1999

47. A polymorphism within the promoter of the TGFβ1 gene is associated with radiation sensitivity using an objective radiologic endpoint.

Author

Kelsey CR, Jackson L, Langdon S, Owzar K, Hubbs J, Vujaskovic Z, Das S, Marks LB, Kelsey, Chris R, Jackson, Lauren, Langdon, Scott, Owzar, Kouros, Hubbs, Jessica, Vujaskovic, Zeljko, Das, Shiva, and Marks, Lawrence B

Abstract

Purpose: To evaluate whether single nucleotide polymorphisms (SNPs) in the transforming growth factor-β1 (TGFβ1) gene are associated with radiation sensitivity using an objective radiologic endpoint. Methods and Materials: Preradiation therapy and serial postradiation therapy single photon emission computed tomography (SPECT) lung perfusion scans were obtained in patients undergoing treatment for lung cancer. Serial blood samples were obtained to measure circulating levels of TGFβ1. Changes in regional perfusion were related to regional radiation dose yielding a patient-specific dose-response curve, reflecting the patient's inherent sensitivity to radiation therapy. Six TGFβ1 SNPs (-988, -800, -509, 869, 941, and 1655) were assessed using high-resolution melting assays and DNA sequencing. The association between genotype and slope of the dose-response curve, and genotype and TGFβ1 ratio (4-week/preradiation therapy), was analyzed using the Kruskal-Wallis test. Results: 39 white patients with preradiation therapy and ≥ 6-month postradiation therapy SPECT scans and blood samples were identified. Increasing slope of the dose-response curve was associated with the C(-509)T SNP (p = 0.035), but not the other analyzed SNPs. This SNP was also associated with higher TGFβ1 ratios. Conclusions: This study suggests that a polymorphism within the promoter of the TGFβ1 gene is associated with increased radiation sensitivity (defined objectively by dose-dependent changes in SPECT lung perfusion). [ABSTRACT FROM AUTHOR]

Published
2012
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48. High-content screening identifies a small molecule that restores AP-4-dependent protein trafficking in neuronal models of AP-4-associated hereditary spastic paraplegia.

Author

Saffari A, Brechmann B, Böger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu JE, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore ED, Barrett L, Borner GHH, Davies AK, Ebrahimi-Fakhari D, and Sahin M

Subjects
Humans, Proteomics, Neurons metabolism, Protein Transport, Proteins metabolism, Mutation, Spastic Paraplegia, Hereditary drug therapy, Spastic Paraplegia, Hereditary genetics, Spastic Paraplegia, Hereditary metabolism
Abstract

Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adapter protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, BCH-HSP-C01, that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate potential mechanisms of action of BCH-HSP-C01. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future studies., (© 2024. The Author(s).)

Published
2024
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49. ALDH5A1-deficient iPSC-derived excitatory and inhibitory neurons display cell type specific alterations.

Author

Afshar-Saber W, Teaney NA, Winden KD, Jumo H, Shi X, McGinty G, Hubbs J, Chen C, Tokatly Latzer I, Gasparoli F, Ebrahimi-Fakhari D, Buttermore ED, Roullet JB, Pearl PL, and Sahin M

Subjects
Humans, Male, Female, Neurons metabolism, gamma-Aminobutyric Acid metabolism, Succinate-Semialdehyde Dehydrogenase genetics, Induced Pluripotent Stem Cells metabolism, Amino Acid Metabolism, Inborn Errors drug therapy, Amino Acid Metabolism, Inborn Errors genetics, Amino Acid Metabolism, Inborn Errors metabolism
Abstract

Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a neurometabolic disorder caused by ALDH5A1 mutations presenting with autism and epilepsy. SSADHD leads to impaired GABA metabolism and results in accumulation of GABA and γ-hydroxybutyrate (GHB), which alter neurotransmission and are thought to lead to neurobehavioral symptoms. However, why increased inhibitory neurotransmitters lead to seizures remains unclear. We used induced pluripotent stem cells from SSADHD patients (one female and two male) and differentiated them into GABAergic and glutamatergic neurons. SSADHD iGABA neurons show altered GABA metabolism and concomitant changes in expression of genes associated with inhibitory neurotransmission. In contrast, glutamatergic neurons display increased spontaneous activity and upregulation of mitochondrial genes. CRISPR correction of the pathogenic variants or SSADHD mRNA expression rescue various metabolic and functional abnormalities in human neurons. Our findings uncover a previously unknown role for SSADHD in excitatory human neurons and provide unique insights into the cellular and molecular basis of SSADHD and potential therapeutic interventions., Competing Interests: Declaration of Competing Interest Mustafa Sahin reports grant support from Novartis, Biogen, Astellas, Aeovian, Bridgebio, and Aucta. He has served on Scientific Advisory Boards for Novartis, Roche, Regenxbio, SpringWorks Therapeutics, Jaguar Therapeutics and Alkermes., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Published
2024
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50. High-Content Small Molecule Screen Identifies a Novel Compound That Restores AP-4-Dependent Protein Trafficking in Neuronal Models of AP-4-Associated Hereditary Spastic Paraplegia.

Author

Saffari A, Brechmann B, Boeger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu J, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore E, Barrett L, Borner G, Davies A, Sahin M, and Ebrahimi-Fakhari D

Abstract

Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect novel therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adaptor protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia, characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, C - 01 , that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate putative molecular targets of C - 01 and potential mechanisms of action. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future Investigational New Drug (IND)-enabling studies., Competing Interests: COMPETING INTERESTS This work was supported by a joint research agreement between Boston Children’s Hospital and Mitobridge Inc., now owned by Astellas Pharmaceuticals Inc.. D.E.F. has served as a consultant to Health Advances LLC, has received speaker honoraria from the Movement Disorders Society, and publishing royalties from Cambridge University Press. M.S. reports grant support from Novartis, Biogen, Astellas, Aeovian, Bridgebio, and Aucta unrelated to this project. He has served on Scientific Advisory Boards for Novartis, Roche, Regenxbio, SpringWorks Therapeutics, Jaguar Therapeutics and Alkermes.

Published
2023
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