10,835 research outputs found
Large Area Crop Inventory Experiment (LACIE). Level 3 baseline; LACIE commodity data control plan for JSC
There are no author-identified significant results in this report
Effects of intra- and inter-laminar resin content on the mechanical properties of toughened composite materials
Composite materials having multiphase toughened matrix systems and laminate architectures characterized by resin-rich interlaminar layers (RIL) have been the subject of much recent attention. Such materials are likely to find applications in thick compressively loaded structures such as the keel area of commercial aircraft fuselages. The effects of resin content and its interlaminar and intralaminar distribution on mechanical properties were investigated with test and analysis of two carbon-epoxy systems. The RIL was found to reduce the in situ strengthening effect for matrix cracking in laminates. Mode 2 fracture toughness was found to increase with increasing RIL thickness over the range investigated, and Mode 1 interlaminar toughness was negligibly affected. Compressive failure strains were found to increase with increasing resin content for specimens having no damage, holes, and impact damage. Analytical tools for predicting matrix cracking of off-axis plies and damage tolerance in compression after impact (CAI) were successfully applied to materials with RIL
Closed-circuit television welding- electrode guidance system
Closed-circuit TV camera is mounted parallel to electrode and moves along with it. Camera is scanned along seam so seam is viewed parallel with scan lines on TV monitor. Two fiber optics illuminators are attached to guidance system; they illuminate seam for TV camera
Bacteria and the Aging and Longevity of Caenorhabditis elegans
The molecular genetic analysis of longevity of Caenorhabditis elegans has yielded fundamental insights into evolutionarily conserved pathways and processes governing the physiology of aging. Recent studies suggest that interactions between C. elegans and its microbial environment may influence the aging and longevity of this simple host organism. Experimental evidence supports a role for bacteria in affecting longevity through distinct mechanisms—as a nutrient source, as a potential pathogen that induces double-edged innate immune and stress responses, and as a coevolved sensory stimulus that modulates neuronal signaling pathways regulating longevity. Motivating this review is the anticipation that the molecular genetic dissection of the integrated host immune, stress, and neuroendocrine responses to microbes in C. elegans will uncover basic insights into the cellular and organismal physiology that governs aging and longevity.National Institute of General Medical Sciences (U.S.)Ellison Medical Foundatio
Radio Signatures of HI at High Redshift: Mapping the End of the ``Dark Ages''
The emission of 21-cm radiation from a neutral intergalactic medium (IGM) at
high redshift is discussed in connection with the thermal and ionization
history of the universe. The physical mechanisms that make such radiation
detectable against the cosmic microwave background include Ly_alpha coupling of
the hydrogen spin temperature to the kinetic temperature of the gas and
preheating of the IGM by the first generation of stars and quasars. Three
different signatures are investigated in detail: (a) the fluctuations in the
redshifted 21-cm emission induced by the gas density inhomogeneities that
develop at early times in cold dark matter (CDM) dominated cosmologies; (b) the
sharp absorption feature in the radio sky due to the rapid rise of the Ly_alpha
continuum background that marks the birth of the first UV sources in the
universe; and (c) the 21-cm emission and absorption shells that are generated
on several Mpc scales around the first bright quasars. Future radio
observations with projected facilities like the Giant Metrewave Radio Telescope
and the Square Kilometer Array may shed light on the power spectrum of density
fluctuations at z>5, and map the end of the "dark ages", i.e. the transition
from the post-recombination universe to one populated with radiation sources.Comment: LateX, 19 pages, 5 figures, significantly revised version to be
published in the Ap
Expanding the Therapeutic Window for CAR T Cell Therapy in Solid Tumors: The Knowns and Unknowns of CAR T Cell Biology
A major obstacle for chimeric antigen receptor (CAR) T cell therapy in solid tumors is the lack of truly tumor-specific target antigens, which translates to the targeting of tumor-associated antigens (TAAs) overexpressed on tumors but shared with normal organs, raising safety concerns. In addition, expression of TAAs in solid tumors is particularly heterogeneous. In this regard, it is critical to deeply understand the sensitivity of CAR T cells, especially against low-density targets and the possible therapeutic window of antigen density targeted by CAR T cells. In this review, we discuss the recent findings of mechanisms of antigen recognition through CAR, including immunological synapse formation, and the impact of target antigen density for induction of distinct T cell functions. We also discuss rational strategies to adjust and expand the therapeutic window for effective and safe targeting of solid tumors by CAR T cell platforms
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