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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Probing nuclei by deeply penetrating and peripherally interacting Hadron: Bridging low and high-energy processes

The search for signals of new phenomenon is an important trend in the contemporary strong interaction physics. The nuclear J/{psi} suppressions are considered as like candidates for the signals of unusual events, e.g. quark-gluon plasma. They were explained in the framework of Glauber approximation. On the contrary, we show that new experimental data on the total cross section of K{sup +}-nucleus interaction at intermediate energies cannot be described by the novel well-elaborated Glauber model. This may indicate a unique event in ground state nuclei (in-medium effect)

74 ATOMIC AND MOLECULAR PHYSICS↗
NASA NTRS1961

Base Flow Characteristics for Several Four-Clustered Rocket Configurations at Mach Numbers from 2.0 to 3.5

A generalized study of base flow phenomena has been conducted with four 500-pound-thrust JP-4 fuel-liquid-oxygen rocket motors installed in the base of a 12-inch-diameter cylindrical model. Data were obtained over a Mach number and nozzle pressure ratio range of 2.0 to 3.5 and 340 to 600, respectively. Base heat flux, gas temperature, and pressure were highest in the center of the cluster core and decreased in a radial direction. Although a maximum heat flux of 93 Btu per square foot per second was measured within the cluster core, peripheral heat fluxes were low, averaging about 5 Btu per square foot per second for all configurations. Generally base heat flux was found to be independent of Mach number over the range investigated. Base heat flux within the cluster core was decreased by increasing motor spacing, motor extension, a combination of increasing nozzle area ratio and decreasing exit angle and gimbaling the two side engines. Small amounts of nitrogen injected within the cluster core sharply reduced core heat flux.

Musial, Norman T.↗
DOE OSTI2018

Detecting Payload Attacks on Programmable Logic Controllers (PLCs)

Programmable logic controllers (PLCs) play critical roles in industrial control systems (ICS). Providing hardware peripherals and firmware support for control programs (i.e., a PLC’s “payload”) written in languages such as ladder logic, PLCs directly receive sensor readings and control ICS physical processes. An attacker with access to PLC development software (e.g., by compromising an engineering workstation) can modify the payload program and cause severe physical damages to the ICS. To protect critical ICS infrastructure, we propose to model runtime behaviors of legitimate PLC payload program and use runtime behavior monitoring in PLC firmware to detect payload attacks. By monitoring the I/O access patterns, network access patterns, as well as payload program timing characteristics, our proposed firmware-level detection mechanism can detect abnormal runtime behaviors of malicious PLC payload. Using our proof-of-concept implementation, we evaluate the memory and execution time overhead of implementing our proposed method and find that it is feasible to incorporate our method into existing PLC firmware. In addition, our evaluation results show that a wide variety of payload attacks can be effectively detected by our proposed approach. The proposed firmware-level payload attack detection scheme complements existing bumpin- the-wire solutions (e.g., external temporal-logic-based model checkers) in that it can detect payload attacks that violate realtime requirements of ICS operations and does not require any additional apparatus.

42 ENGINEERING↗
DOE OSTI2026

Deactivating Emission in Azulene via Solvent-Induced (Anti)Aromaticity

Anti-Kasha emission is a coveted feature in optoelectronics, with promise in areas such as imaging, sensing, and the production of white-light LEDs via dual-photon emission. Despite being a rare feature in organic systems, anti-Kasha emission is readily observed in the deceptively simple molecule azulene, which possesses two bright singlet states in the UV–visible spectrum and readily emits from the S 2 state. With dominant anti-Kasha emission and decades of synthetic study, azulene is a perfect candidate for novel material fabrication; however, large gaps persist in understanding the photophysics of even the simple parent compound. These range from competing, experimentally unverified models of azulene reactivity and aromaticity to the unexplained deactivation of anti-Kasha emission in a host of azulene derivatives. Herein, we use fluorescence and transient absorption spectroscopies to explore the detailed solvent dependence of azulene photophysics. We discover a tunable reduction in the S 2 lifetime via weak complexation with aromatic solvents. Interestingly, our results are independent of polarity, highlighting the primacy of peripherally delocalized 10-π Hückel aromaticity over zwitterionic character. When the dipolar character is enhanced through chemical functionalization, we observe even greater sensitivity to solvent aromaticity and more rapid quenching, revealing the role of conical intersections in azulenes with zwitterionic excited states. Overall, this work provides essential mechanistic insight into the photophysics of azulene and reveals a simple new approach to control the excited-state aromaticity and anti-Kasha emission in this class of materials.

Absorption↗
DOE OSTI2016

Low Dose Ionizing Radiation Modulates Immune Function

In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a “Th2 polarized” immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in the dose range of 5 to 50 cGy.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗
NASA NTRS1997

Left ventricular diastolic filling with an implantable ventricular assist device: beat to beat variability with overall improvement

OBJECTIVES: We studied the effects of left ventricular (LV) unloading by an implantable ventricular assist device on LV diastolic filling. BACKGROUND: Although many investigators have reported reliable systemic and peripheral circulatory support with implantable LV assist devices, little is known about their effect on cardiac performance. METHODS: Peak velocities of early diastolic filling, late diastolic filling, late to early filling ratio, deceleration time of early filling, diastolic filling period and atrial filling fraction were measured by intraoperative transesophageal Doppler echocardiography before and after insertion of an LV assist device in eight patients. A numerical model was developed to simulate this situation. RESULTS: Before device insertion, all patients showed either a restrictive or a monophasic transmitral flow pattern. After device insertion, transmitral flow showed rapid beat to beat variation in each patient, from abnormal relaxation to restrictive patterns. However, when the average values obtained from 10 consecutive beats were considered, overall filling was significantly normalized from baseline, with early filling velocity falling from 87 +/- 31 to 64 +/- 26 cm/s (p < 0.01) and late filling velocity rising from 8 +/- 11 to 32 +/- 23 cm/s (p < 0.05), resulting in an increase in the late to early filling ratio from 0.13 +/- 0.18 to 0.59 +/- 0.38 (p < 0.01) and a rise in the atrial filling fraction from 8 +/- 10% to 26 +/- 17% (p < 0.01). The deceleration time (from 112 +/- 40 to 160 +/- 44 ms, p < 0.05) and the filling period corrected by the RR interval (from 39 +/- 8% to 54 +/- 10%, p < 0.005) were also significantly prolonged. In the computer model, asynchronous LV assistance produced significant beat to beat variation in filling indexes, but overall a normalization of deceleration time as well as other variables. CONCLUSIONS: With LV assistance, transmitral flow showed rapidly varying patterns beat by beat in each patient, but overall diastolic filling tended to normalize with an increase of atrial contribution to the filling. Because of the variable nature of the transmitral flow pattern with the assist device, the timing of the device cycle must be considered when inferring diastolic function from transmitral flow pattern.

Non-NASA Center↗
DOE OSTI2021

Centrality dependence of J /ψ and ψ (2S) production and nuclear modification in p-Pb collisions at \( \sqrt{s_{\mathrm{NN}}} \) = 8 . 16 TeV

The inclusive production of the J/ ψ and ψ (2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair \( \sqrt{s_{\mathrm{NN}}} \) = 8 . 16 TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals – 4 . 46 < y cms < – 2 . 96 (Pb-going direction) and 2 . 03 < y cms < 3 . 53 (p-going direction), down to zero transverse momentum ( p T ). The J/ ψ and ψ (2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The p T -differential J/ ψ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average \( \left\langle {p}_{\mathrm{T}}\right\rangle \) and \( \left\langle {p}_{\mathrm{T}}^2\right\rangle \) values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/ ψ increases from below unity in peripheral collisions to above unity in central collisions, while for the ψ (2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at \( \sqrt{s_{\mathrm{NN}}} \) = 5 . 02 TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Systematic Engineering of Single Substitution in Zirconium Metal–Organic Frameworks toward High-Performance Catalysis

Zirconium-based metal–organic frameworks (Zr-MOFs) exhibit great structural tunability and outstanding chemical stability, rendering them promising candidates for a wide range of practical applications. In this work, we synthesized a series of isostructural PCN-224 analogues functionalized by ethyl, bromo, chloro, and fluoro groups on the porphyrin unit, which allowed us to explicitly study the effects of electron-donating and electron-withdrawing substituents on catalytic performance in MOFs. Owing to the different electronic properties of ethyl, bromo, chloro, and fluoro substitutes, the molecular-level control over the chemical environment surrounding a catalytic center could be readily achieved in our MOFs. To investigate the effects of these substitutes on catalytic activity and selectivity, the oxidation of 3-methylpentane to corresponding alcohols and ketones was utilized as a model reaction. Within these five analogues of PCN-224, an extremely high turnover number of 7680 and turnover frequency of 10 240 h –1 was achieved by simply altering the substitutes on porphyrin rings. Moreover, a remarkable 99% selectivity of the tertiary alcohol over the five other possible by-products are realized. We demonstrate that this strategy can be used to efficiently screen a suitable peripheral environment around catalytic cores in MOFs for catalysis.

36 MATERIALS SCIENCE↗
DOE OSTI2015

SU-E-T-352: Effects of Skull Attenuation and Missing Backscatter On Brain Dose in HDR Treatment of the Head with Surface Applicators

Purpose: To calculate the effect of lack of backscatter from air and attenuation of bone on dose distributions in brachytherapy surface treatment of head. Existing treatment planning systems based on TG43 do not account for heterogeneities, and thus may overestimate the dose to the brain. While brachytherapy generally has rapid dose falloff, the dose to the deeper tissues (in this case, the brain) can become significant when treating large curved surfaces. Methods: Applicator geometries representing a range of clinical cases were simulated in MCNP5. An Ir-192 source was modeled using the energy spectrum presented by TG-43. The head phantom was modeled as a 7.5-cm radius water sphere, with a 7 -mm thick skull embedded 5-mm beneath the surface. Dose values were calculated at 20 points inside the head, in which 10 of them were on the central axis and the other 10 on the axis connecting the central of the phantom with the second to last source from the applicator edge. Results: Central and peripheral dose distributions for a range of applicator and head sizes are presented. The distance along the central axis at which the dose falls to 80% of the prescribed dose (D80) was 7 mm for a representative small applicator and 9 mm for a large applicator. Corresponding D50 and D30 for the same small applicator were 17 mm and 32 mm respectively. D50 and D30 for the larger applicator were 32 mm and 60 mm respectively. These results reflect the slower falloff expected for larger applicators on a curved surface. Conclusion: Our results can provide guidance for clinicians to calculate the dose reduction effect due to bone attenuation and the lack of backscatter from air to estimate the brain dose for the HDR treatments of surface lesions.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1983

Hematopoiesis in antiorthostatic, hypokinesic rats

Rats exposed to antiorthostatic, hypokinesia showed the following effects which are comparable to those seen in man during or after space flight: weight loss, reduced food and water consumption, transient increases in peripheral hematocrit and RBC count, decreasing MCV and reduced reticulocyte count. In addition, the hemoglobin P50 was shifted to the right. A significant shortening of RBC t1/2 was only seen after suspension. Changes in leukocyte and platelet numbers in suspended rats were also comparable to those in man during space flight, but leukocyte PHA sensitivity in rats showed no consistent alteration. The results demonstrate that this model reproduces many of the hematological effects of space flight and has potential as a tool in understanding the hematopoietic response to zero gravity.

Dunn, C. D. R.↗
NASA NTRS1998

The universal ancestor

A genetic annealing model for the universal ancestor of all extant life is presented; the name of the model derives from its resemblance to physical annealing. The scenario pictured starts when "genetic temperatures" were very high, cellular entities (progenotes) were very simple, and information processing systems were inaccurate. Initially, both mutation rate and lateral gene transfer levels were elevated. The latter was pandemic and pervasive to the extent that it, not vertical inheritance, defined the evolutionary dynamic. As increasingly complex and precise biological structures and processes evolved, both the mutation rate and the scope and level of lateral gene transfer, i.e., evolutionary temperature, dropped, and the evolutionary dynamic gradually became that characteristic of modern cells. The various subsystems of the cell "crystallized," i.e., became refractory to lateral gene transfer, at different stages of "cooling," with the translation apparatus probably crystallizing first. Organismal lineages, and so organisms as we know them, did not exist at these early stages. The universal phylogenetic tree, therefore, is not an organismal tree at its base but gradually becomes one as its peripheral branchings emerge. The universal ancestor is not a discrete entity. It is, rather, a diverse community of cells that survives and evolves as a biological unit. This communal ancestor has a physical history but not a genealogical one. Over time, this ancestor refined into a smaller number of increasingly complex cell types with the ancestors of the three primary groupings of organisms arising as a result.

NASA Discipline Exobiology↗
DOE OSTI2012

Neuregulin-1 is neuroprotective in a rat model of organophosphate-induced delayed neuronal injury

Current medical countermeasures against organophosphate (OP) nerve agents are effective in reducing mortality, but do not sufficiently protect the CNS from delayed brain damage and persistent neurological symptoms. In this study, we examined the efficacy of neuregulin-1 (NRG-1) in protecting against delayed neuronal cell death following acute intoxication with the OP diisopropylflurophosphate (DFP). Adult male Sprague–Dawley rats were pretreated with pyridostigmine (0.1 mg/kg BW, i.m.) and atropine methylnitrate (20 mg/kg BW, i.m.) prior to DFP (9 mg/kg BW, i.p.) intoxication to increase survival and reduce peripheral signs of cholinergic toxicity but not prevent DFP-induced seizures or delayed neuronal injury. Pretreatment with NRG-1 did not protect against seizures in rats exposed to DFP. However, neuronal injury was significantly reduced in most brain regions by pretreatment with NRG-1 isoforms NRG-EGF (3.2 μg/kg BW, i.a) or NRG-GGF2 (48 μg/kg BW, i.a.) as determined by FluroJade-B labeling in multiple brain regions at 24 h post-DFP injection. NRG-1 also blocked apoptosis and oxidative stress-mediated protein damage in the brains of DFP-intoxicated rats. Administration of NRG-1 at 1 h after DFP injection similarly provided significant neuroprotection against delayed neuronal injury. These findings identify NRG-1 as a promising adjuvant therapy to current medical countermeasures for enhancing neuroprotection against acute OP intoxication. -- Highlights: ► NRG-1 blocked DFP induced neuronal injury. ► NRG-1 did not protect against seizures in rats exposed to DFP. ► NRG-1 blocked apoptosis and oxidative stress in the brains of DFP-intoxicated rats. ► Administration of NRG-1 at 1 h after DFP injection prevented delayed neuronal injury.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Structural and Functional Evidence for Testosterone Activation of GPRC6A in Peripheral Tissues

G protein-coupled receptor (GPCR) family C group 6 member A (GPRC6A) is a multiligand GPCR that is activated by cations, L-amino acids, and osteocalcin. GPRC6A plays an important role in the regulation of testosterone (T) production and energy metabolism in mice. T has rapid, transcription-independent (nongenomic) effects that are mediated by a putative GPCR. We previously found that T can activate GPRC6A in vitro, but the possibility that T is a ligand for GPRC6A remains controversial. Here, we demonstrate direct T binding to GPRC6A and construct computational structural models of GPRC6A that are used to identify potential binding poses of T. Mutations of the predicted binding site residues were experimentally found to block T activation of GPRC6A, in agreement with the modeling. Using Gpr6ca(-/-) mice, we confirmed that loss of GPRC6A resulted in loss of T rapid signaling responses and elucidated several biological functions regulated by GPRC6A-dependent T rapid signaling, including T stimulation of insulin secretion in pancreatic islets and enzyme expression involved in the biosynthesis of T in Leydig cells. Finally, we identified a stereo-specific effect of an R-isomer of a selective androgen receptor modulator that is predicted to bind to and shown to activate GPRC6A but not androgen receptor. Together, our data show that GPRC6A directly mediates the rapid signaling response to T and uncovers previously unrecognized endocrine networks.

Pi, Min↗
DOE OSTI2015

Characterizing Rat PNS Electrophysiological Response to Electrical Stimulation Using in vitro Chip-Based Human Investigational Platform (iCHIP)

Ex vivo systems and organ-on-a-chip technology offer an unprecedented approach to modeling the inner workings of the human body. The ultimate goal of LLNL’s in vitro Chip-based Human Investigational Platform (iCHIP) is to integrate multiple organ tissue cultures using microfluidic channels, multi-electrode arrays (MEA), and other biosensors in order to effectively simulate and study the responses and interactions of the major organs to chemical and physical stimulation. In this study, we focused on the peripheral nervous system (PNS) component of the iCHIP system. Specifically we sought to expound on prior research investigating the electrophysiological response of rat dorsal root ganglion cells (rDRGs) to chemical exposures, such as capsaicin. Our aim was to establish a protocol for electrical stimulation using the iCHIP device that would reliably elicit a characteristic response in rDRGs. By varying the parameters for both the stimulation properties – amplitude, phase width, phase shape, and stimulation/ return configuration – and the culture conditions – day in vitro and neural cell types - we were able to make several key observations and uncover a potential convention with a minimal number of devices tested. Future work will seek to establish a standard protocol for human DRGs in the iCHIP which will afford a portable, rapid method for determining the effects of toxins and novel therapeutics on the PNS.

42 ENGINEERING↗
NASA NTRS1977

An in-flight simulation of VTOL hover control concepts

Results of several parametric ground-based simulations covering a variety of VTOL in-hover control concepts are reviewed. The systems considered are angular acceleration, rate, and attitude control, as well as translational rate control. Since many cues are severely restricted by ground-based simulation (e.g., motion, peripheral vision, and environment), some form of in-flight validation of these results is desired. Such a study has been undertaken utilizing the NASA Ames X-14B VTOL aircraft. This in-flight simulator has been configured with a fly-by-wire capability in the hover mode through an analog-/digital variable stability system. This system permits the implementation of either response-feedback or model-following type of control. A comparison of flight- and ground-based data is shown for the attitude control system with the X-14B being flown in both a tethered hover and a free-flight hover.

Corliss, L. D.↗
NASA NTRS2013

Hyperspectral Microwave Atmospheric Sounder (HyMAS) Architecture and Design Accommodations

The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term "hyperspectral microwave" is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth s atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4-9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the scan head computer, and the slip rings developed for CoSMIR was the starting point. The next step was to modify the antenna faceplate to accommodate the dimensions of the three dual polarization Gaussian Optics Antenna (GOA) assemblies. Two mechanical concepts for the core technology, the hyperspectral IFP, were captured in a design tradeoff. Connector models considered minimum bend radii for the IFP analog connectors. Hyperspectral imaging is accomplished by strategically using a short wavelength intermediate frequency of 18-29 GHz, and thus reducing the size of components in the connection of the front end to the IFP. The SMK (2.92mm) Series connector will lay near the hinge line to minimize its flexing. The digital output of the IFP will use a Serial Peripheral Interface (SPI) that must be accommodated by the scan head computer. To make that computer more reliable, maintainable, and forward compatible with the 52 HyMAS channels, a testbed of the scan head, calibration, and archive computers and the PIC24 microprocessor that resides on the IFP is in development. The computers will be programmed using a new framework application called Interoperable Remote Component (IRC). This software allows flexibility to program computers that communicate with each other and can adapt easily to the emerging HyMAS requirements for data format, algorithms, and graphical user interface (GUI). It is expected that the CoSMIR instrument will cut over to the IRC after it is adapted on an updated CoSMIR testbed.

Hilliard, Lawrence↗
DOE OSTI2013

SL-01, an oral derivative of gemcitabine, inhibited human breast cancer growth through induction of apoptosis

Highlights: •SL-01 is an oral derivative of gemcitabine. •SL-01 possessed activity against human breast cancer growth via apoptotic induction. •SL-01’s activity was more potently than that of gemcitabine. •SL-01 inhibited cancer growth without toxicity to mice. -- Abstract: SL-01 is an oral derivative of gemcitabine that was synthesized by introducing the moiety of 3-(dodecyloxycarbonyl) pyrazine-2-carbonyl at N4-position on cytidine ring of gemcitabine. We aimed to evaluate the efficacy of SL-01 on human breast cancer growth. SL-01 significantly inhibited MCF-7 proliferation as estimated by colorimetric assay. Flow cytometry assay indicated the apoptotic induction and cell cycle arrest in G1 phase. SL-01 modulated the expressions of p-ATM, p53 and p21 and decrease of cyclin D1 in MCF-7 cells. Further experiments were performed in a MCF-7 xenografts mouse model. SL-01 by oral administration strongly inhibited MCF-7 xenografts growth. This effect of SL-01 might arise from its roles in the induction of apoptosis. Immunohistochemistry assay showed the increase of TUNEL staining cells. Western blotting indicated the modulation of apoptotic proteins in SL-01-treated xenografts. During the course of study, there was no evidence of toxicity to mice. In contrast, the decrease of neutrophil cells in peripheral and increase of AST and ALT levels in serum were observed in the gemcitabine-treated mice. Conclusion: SL-01 possessed similar activity against human breast cancer growth with gemcitabine, whereas, with lower toxicity to gemcitabine. SL-01 is a potent oral agent that may supplant the use of gemcitabine.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

First measurement of the |t|-dependence of coherent J/ψ photonuclear production

The first measurement of the cross section for coherent J/ψ photoproduction as a function of |t|, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the ALICE detector in ultra-peripheral Pb–Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}$=5.02TeV with the J/ψ produced in the central rapidity region |y|<0.8, which corresponds to the small Bjorken-x range (0.3-1.4)×10 -3 . The measured |t|-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according to the leading-twist approximation, or gluon-saturation effects from the impact-parameter dependent Balitsky–Kovchegov equation. These new results are therefore a valid tool to constrain the relevant model parameters and to investigate the transverse gluonic structure at very low Bjorken-x.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗