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At least 829 records · Page 46

Newly developed sugarbeet lines with altered postharvest respiration rates differ in transcription factor and glycolytic enzyme expression

Respiration is the principal cause for postharvest sucrose loss in sugarbeet (Beta vulgaris L.) roots. Although reductions in respiration rate could mitigate these losses, developing sugarbeet cultivars and storage procedures that reduce respiration are hindered by a lack of knowledge of the genetic and metabolic factors that control storage respiration rate. Research was conducted to identify genes and gene products that affect storage respiration rate by creating two sugarbeet lines that differ in respiration rate and characterizing gene expression differences between these lines. Sugarbeet lines F1056 and F1057, which differ by up to 42% in respiration rate, were created by divergent selection of a sugarbeet population using root respiration rate after 30 d in storage as the principal selection criterion. RNA sequencing identified 287 differentially expressed genes (DEGs) between these lines on the day of harvest and after 28-d storage. Of these DEGs, nine encoded transcription factors and five encoded enzymes involved in the respiratory pathway. Other DEGs contributed to a variety of biological and molecular functions based on gene ontology classifications. Of respiratory pathway DEGS, genes for NAD+- and NADP+-dependent forms of glyceraldehyde-3-phosphate dehydrogenase were of note due to their high upregulation in the high respiring line and for their established role in glycolysis, a pathway identified as a likely bottleneck in respiratory substrate production. Overall, lines F1056 and F1057 provide new tools for investigating genetic and physiological differences in storage respiration rate, and their DEGs identify candidates for genes affecting sugarbeet root respiration rate.

59 BASIC BIOLOGICAL SCIENCES↗

Genetic mapping of sugarcane aphid resistance in sorghum line SC112-14

Sugarcane aphid [Melanaphis sacchari (Zehntner)] is a destructive pest that has had an economic effect on sorghum in North America since 2013. The identification, development, and use of resistant sorghum germplasm is the most feasible strategy to control the pest. Nevertheless, the genetic control of sugarcane aphid (SCA) resistance is unknown for most sorghum resistant lines. To identify the genetic regions that confer SCA resistance in sorghum line SC112-14, 103 recombinant inbred lines (RILs) derived by its cross with the susceptible line PI 609251 were evaluated for their SCA resistance response in Georgia during two consecutive years. The resistance response was determined based on two ratings (2 wk apart) for aphid population size (APS) and aphid-induced plant damage (APD) each year. Segregation for SCA resistance was observed for the first APS and both APD ratings, and the broad-sense heritability estimate ranged from .71 to .76, respectively. A quantitative trait locus analysis using a high-density linkage map of 3,852 single nucleotide polymorphisms (SNPs) detected an 81-kb genomic region on chromosome 6 that explained 50–55% of the phenotypic variation. Comparative mapping analysis found that the resistance locus in SC112-14 is located 8- and 10-cM upstream of the Henong 16 (RMES1) and Tx2783 resistance loci, respectively, and encloses the SNP Sbv3.1_06_2316351 associated in Haitian resistant lines. Therefore, the line SC112-14 is an additional SCA resistance source that can be combined or strategically used with other resistance sources to assure a more robust host plant resistance to the SCA.

60 APPLIED LIFE SCIENCES↗

Hysteresis Effects on a Non-uniform Transmission Line with Induced Quantum Mechanical Atomic Transitions

This study describes the effect of hysteresis on the generation of the higher harmonics in the line voltage and current in a non-uniform transmission line when we include a quadratic non-linear term having memory to account for the hysteresis effect in the inductance part of line. The simulational analysis using MATLAB is presented which works with a non-uniform line having hysteresis. These simulations are based on a theoretical spatial Fourier analysis combined with perturbation theory which is used without bothering about source and load. The line differential equations are solved approximately in the space- time-frequency domain using perturbation theory and the numerical computations have been carried out for the voltage and current amplitude characteristics. In Appendix 1, some theoretical explanations that support our non-linear memory-based hysteresis model based on Landau’s equation of precession of a magnetic moment in a magnetic field are included. This paper also includes a brief derivation of atomic transition probability produced by e-m radiation from the transmission line falling on an atom in the far field zone. This calculation enables us to derive maximum likelihood estimation(MLE) of the hysteresis parameters by measuring which atomic transitions have occurred.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Predicting multi-nodal in-nozzle particle interactions in high-viscosity fluid mediums for acoustophoretic direct-ink writing of line-patterned composites

Patterned functional materials offer improved properties (electrical, thermal, etc.) over their bulk counterparts in many applications, including energy storage, flexible electronics, and sensors. However, manufacturing approaches for patterning materials over large areas with features on the order of hundreds of microns or less are limited. Acoustophoresis, which uses acoustic forces to control particle arrangement in a fluid medium, is a pathway to address this challenge. This process is dependent on particle and fluid properties and enables patterning of a broad range of materials. Herein, a model with experimental validation is presented to demonstrate that acoustophoresis can be combined with direct-ink writing (DIW) to fabricate line patterns over large cm-scale areas. An in-nozzle particle interaction model was developed to investigate the impact of processing conditions on multi-nodal acoustophoretic DIW. The model predicts patterned line widths within a factor of two relative to experimental results for a high viscosity case study. Here, the model was used to investigate the impact of frequency, particle loading, particle radius, and acoustic pressure on line width and patterning time, providing critical feedback regarding the processing conditions suitable for a target application. Model results illustrate that frequency has the greatest impact on line patterns: increasing from 1 to 3 MHz resulted in a greater than 65% reduction in line width and a greater than 85% reduction in patterning time. Additionally, experiments were conducted with an alumina-epoxy ink and a ~21 cm 2 area pattern was rastered in ~5.5 minutes, demonstrating a path towards large-area line-patterned composite fabrication.

25 ENERGY STORAGE↗

Mutually unbiased projectors and duality between lines and bases in finite quantum systems

Quantum systems with variables in the ring Z(d) are considered, and the concepts of weak mutually unbiased bases and mutually unbiased projectors are discussed. The lines through the origin in the Z(d)×Z(d) phase space, are classified into maximal lines (sets of d points), and sublines (sets of d{sub i} points where d{sub i}|d). The sublines are intersections of maximal lines. It is shown that there exists a duality between the properties of lines (resp., sublines), and the properties of weak mutually unbiased bases (resp., mutually unbiased projectors). -- Highlights: •Lines in discrete phase space. •Bases in finite quantum systems. •Duality between bases and lines. •Weak mutually unbiased bases.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Establishment and culture optimization of a new type of pituitary immortalized cell line

The pituitary gland is a center of the endocrine system that controls homeostasis in an organism by secreting various hormones. The glandular anterior pituitary consists of five different cell types, each expressing specific hormones. However, their regulation and the appropriate conditions for their in vitro culture are not well defined. Here, we report the immortalization of mouse pituitary cells by introducing TERT, E6, and E7 transgenes. The immortalized cell lines mainly expressed a thyrotroph-specific thyroid stimulating hormone beta (Tshb). After optimization of the culture conditions, these immortalized cells proliferated and maintained morphological characteristics similar to those of primary pituitary cells under sphere culture conditions in DMEM/F12 medium supplemented with N2, B27, basic FGF, and EGF. These cell lines responded to PKA or PKC pathway activators and induced the expression of Tshb mRNA. Moreover, transplantation of the immortalized cell line into subcutaneous regions and kidney capsules of mice further increased Tshb expression. These results suggest that immortalization of pituitary cells with TERT, E6, and E7 transgenes is a useful method for generating proliferating cells for the in vitro analysis of pituitary regulatory mechanisms. - Highlights: • Mouse pituitary cell lines were immortalized by introducing TERT, E6, and E7. • The immortalized cell lines mainly expressed thyroid stimulating hormone beta. • The cell lines responded to PKA or PKC pathway activators, and induced Tshb.

60 APPLIED LIFE SCIENCES↗

Development and characterization of a hydrogen peroxide-resistant cholangiocyte cell line: A novel model of oxidative stress-related cholangiocarcinoma genesis

Oxidative stress is a cause of inflammation–related diseases, including cancers. Cholangiocarcinoma is a liver cancer with bile duct epithelial cell phenotypes. Our previous studies in animal and human models indicated that oxidative stress is a major cause of cholangiocarcinoma development. Hydrogen peroxide (H{sub 2}O{sub 2}) can generate hydroxyl radicals, which damage lipids, proteins, and nucleic acids, leading to cell death. However, some cells can survive by adapting to oxidative stress conditions, and selective clonal expansion of these resistant cells would be involved in oxidative stress-related carcinogenesis. The present study aimed to establish H{sub 2}O{sub 2}-resistant cell line from an immortal cholangiocyte cell line (MMNK1) by chronic treatment with low-concentration H{sub 2}O{sub 2} (25 μM). After 72 days of induction, H{sub 2}O{sub 2}-resistant cell lines (ox-MMNK1-L) were obtained. The ox-MMNK1-L cell line showed H{sub 2}O{sub 2}-resistant properties, increasing the expression of the anti-oxidant genes catalase (CAT), superoxide dismutase-1 (SOD1), superoxide dismutase-2 (SOD2), and superoxide dismutase-3 (SOD3) and the enzyme activities of CAT and intracellular SODs. Furthermore, the resistant cells showed increased expression levels of an epigenetics-related gene, DNA methyltransferase-1 (DNMT1), when compared to the parental cells. Interestingly, the ox-MMNK1-L cell line had a significantly higher cell proliferation rate than the MMNK1 normal cell line. Moreover, ox-MMNK1-L cells showed pseudopodia formation and the loss of cell-to-cell adhesion (multi-layers) under additional oxidative stress (100 μM H{sub 2}O{sub 2}). These findings suggest that H{sub 2}O{sub 2}-resistant cells can be used as a model of oxidative stress-related cholangiocarcinoma genesis through molecular changes such as alteration of gene expression and epigenetic changes. - Highlights: • An H{sub 2}O{sub 2}-resistant ox-MMNK1-L cells was established from immortalized cholangiocytes. • The resistance was acquired by daily treatment of low H{sub 2}O{sub 2} (25 μM) for 15 passages. • The cells highly expressed catalase, SODs and DNMT1 with rapid cell proliferation. • Pseudopodia and the loss of cell-to-cell adhesion appeared by 100 μM H{sub 2}O{sub 2} treatment. • The resistant cells can be used as a model of oxidative stress-related carcinogenesis.

60 APPLIED LIFE SCIENCES↗

Identification of protein kinase C isozymes involved in the anti-proliferative and pro-apoptotic activities of 10-Methyl-aplog-1, a simplified analog of debromoaplysiatoxin, in several cancer cell lines

Highlights: • 3 out of 9 human cancer cell lines were sensitive to 10-Me-aplog-1. • PKCα and δ were predominantly expressed in the 9 cancer cell lines. • PKCα and/or δ were involved in the anti-proliferative and pro-apoptotic activities of 10-Me-aplog-1. • Mechanism of anti-proliferative and pro-apoptotic activities of 10-Me-aplog-1 was similar to those of DAT and TPA. 10-Me-aplog-1 is a simplified analog of the tumor-promoting compound debromoaplysiatoxin (DAT) and a unique protein kinase C (PKC) activator with limited tumor-promoting and pro-inflammatory activities. 10-Me-aplog-1 inhibits the growth of several cancer cell lines, but the inhibitory mechanism involving PKC isozymes remains unclear. We quantified the amount of PKC isozymes in nine human cancer cell lines that differ in 10-Me-aplog-1 sensitivity. PKCα and δ were the predominant isozymes expressed in all cell lines, but there was no significant correlation between expression levels and anti-proliferative activity. Knocking down PKCα, and/or PKCδ in the three aplog-sensitive cell lines indicated their involvement in the anti-proliferative and pro-apoptotic activities of 10-Me-aplog-1. This finding suggests that PKCα and/or PKCδ activation could be effective for treating certain cancers. Since the mechanism underlying 10-Me-aplog-1's anti-proliferative activities resembles that of DAT, 10-Me-aplog-1 may be regarded as a special key derived from pleiotropic DAT as a bunch of keys.

60 APPLIED LIFE SCIENCES↗

Characterizing responses to gamma radiation by a highly clonogenic fish brain endothelial cell line

Purpose: The clonogenic property and radiobiological responses of a fish brain endothelial cell line, eelB, derived from the American eel were studied. Methods: Clonogenic assays were performed to determine the plating efficiency of the eelB cells and to evaluate the clonogenic survival fractions after direct irradiation to low-dose low-LET gamma radiation or receiving irradiated cell conditioned medium in the bystander effect experiments. Result: eelB had the second highest plating efficiency ever reported to date for fish cell lines. Large eelB macroscopic colonies could be formed in a short period of time and were easy to identify and count. Unlike with other fish clonogenic cell lines, which had a relatively slow proliferation profile, clonogenic assays with the eelB cells could be completed as early as 12 days in culture. After direct irradiation with gamma rays at low doses ranging from 0.1 Gy to 5 Gy, the dose-clonogenic survival curve of the eelB cell line showed a linear trend and did not develop a shoulder region. A classical radio-adaptive response was not induced with the clonogenic survival endpoint when the priming dose (0.1 or 0.5 Gy) was delivered 6 h before the challenge dose (3 or 5 Gy). However, a radio-adaptive response was observed in progeny cells that survived 5 Gy and developed lethal mutations. eelB appeared to lack the ability to produce damaging radiation-induced bystander signals on both eelB and HaCaT recipient cells. Conclusion: eelB cell line could be a very useful cell model in the study of radiation impacts on the aquatic health. - Highlights: • The fish endothelial cell line eelB showed exceptional clonogenic properties. • eelB decreased clonogenic survival upon an increase in gamma dose (0.1-5 Gy). • eelB did not develop a classical radio-adaptive response (RAR). • eelB progenies surviving 5 Gy developed lethal mutations and a RAR-like response. • eelB appeared to lack the ability to produce radiation-induced bystander effects.

54 ENVIRONMENTAL SCIENCES↗

Line positions and intensities of the phosphine (PH 3 ) Pentad near 4.5μm

In order to improve the spectroscopic database for remote sensing of the giant planets, line positions and intensities are determined for the five bands (2ν 2 , ν 2 + ν 4 , 2ν 4 , ν 1 and ν 3 ) that comprise the Pentad of PH 3 between 1950 and 2450 cm -1 . Knowledge of PH 3 spectral line parameters in this region is important for the exploration of dynamics and chemistry on Saturn, (using existing Cassini/VIMS observations) and future near-IR data of Jupiter from Juno and ESA’s Jupiter Icy Moons Explorer (JUICE). For this study, spectra of pure PH 3 from two Fourier transform spectrometers were obtained: (a) five high-resolution (0.00223 cm -1 ), high signal-to-noise (~1800) spectra recorded at room temperature (298.2 K) with the Bruker IFS 125HR Fourier transform spectrometer (FTS) at the Pacific Northwest National Laboratory (PNNL), Richland, Washington and (b) four high-resolution (at 0.0115 cm -1 resolution), high signal-to-noise (~700) spectra recorded at room temperature in the region 1800–5200 cm -1 using the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory (NSO) on Kitt Peak. Individual line parameters above 2150 cm -1 were retrieved by simultaneous multispectrum fittings of all five Bruker spectra, while retrievals with the four Kitt Peak spectra were done in the 1938–2168 cm -1 range spectrum by spectrum and averaged. In all, positions and intensities were obtained for more than 4400 lines. These included 53 A+A- split pairs of transitions (arising due to vibration–rotation interactions (Coriolis-type interaction) between the ν 3 and ν 1 fundamental bands) for K" = 3, 6, and 9. Over 3400 positions and 1750 intensities of these lines were ultimately identified as relatively unblended and modeled up to J = 14 and K = 12 with rms values of 0.00133 cm -1 and 7.7%, respectively. The PH 3 line parameters (observed positions and measured intensities with known quantum assignments) and Hamiltonian constants are reported. Finally, comparisons with other recent studies are discussed.

Environmental Molecular Sciences Laboratory↗

Micro-tensile testing of the bond line in hot isostatic pressed aluminum

Considerable effort is being devoted to development and regulatory qualification of low enriched fuels for research and test reactors by many agencies worldwide. One promising fuel configuration being examined for United States higher power research and test reactors (USHPRRs) are plate-type fuels composed of a metallic uranium-molybdenum foil clad in an aluminum alloy. The two pieces of aluminum alloy cladding are bonded using a hot isostatic pressing method. The mechanical properties of the resulting bond line in the aluminum alloy cladding will vary by the HIP'ing parameters, requiring a need to characterize the bond line. Small scale mechanical testing can provide a path for evaluating the mechanical properties and deformation behavior of the bond line both prior to and following irradiation. Here, in this research, room temperature micro-tensile specimens of non-irradiated and irradiated samples containing an Al alloy (AA 6061) bond line were tested to evaluate its strength and deformation behavior. Observations indicated that the strain rate did not affect the deformation behavior or strength and most of the micro-tensile specimens failed in a ductile mode in grains around the bond line. There was no indication that the microstructural features from the bond line affected the mechanical properties of the micro-tensile specimens. An initial examination was performed on irradiated material but further systematic studies of the effects of irradiation can be performed in the future.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Actin cytoskeleton organization, cell surface modification and invasion rate of 5 glioblastoma cell lines differing in PTEN and p53 status

Glioblastoma cells exhibit highly invasive behavior whose mechanisms are not yet fully understood. The present study explores the relationship between the invasion capacity of 5 glioblastoma cell lines differing in p53 and PTEN status, expression of mTOR and several other marker proteins involved in cell invasion, actin cytoskeleton organization and cell morphology. We found that two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) exhibited the highest invasion rates through the Matrigel or collagen matrix. In DK-MG (p53wt/PTENwt) and GaMG (p53mut/PTENwt) cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG (p53wt/PTENmut), U373-MG and SNB19 (both p53mut/PTENmut) cells preferentially expressed F-actin in filopodia and lamellipodia. Scanning electron microscopy confirmed the abundant filopodia and lamellipodia in the PTEN mutated cell lines. Interestingly, the gene profiling analysis revealed two clusters of cell lines, corresponding to the most (U373-MG and SNB19, i.e. p53 and PTEN mutated cells) and less invasive phenotypes. The results of this study might shed new light on the mechanisms of glioblastoma invasion. - Highlights: • We examine 5 glioblastoma lines on the invasion capacity and actin cytoskeleton. • Glioblastoma cell lines mutated in both p53 and PTEN were the most invasive. • Less invasive cells showed much less lamellipodia, but more actin stress fibers. • A mechanism for the differences in tumor cell invasion is proposed.

60 APPLIED LIFE SCIENCES↗

Characterization of stem-like cells in a new astroblastoma cell line

Cell lines established from tumors are the most commonly used models in cancer research, and their use in recent years has enabled a greater understanding of the biology of cancer and the means to develop effective treatment strategies. Astroblastomas are uncommon neuroepithelial tumors of glial origin, predominantly affecting young people, mainly teenagers and children, predominantly females. To date, only a single study has reported that astroblastomas contain a large number of neural stem-like cells, which had only a partial proliferation capacity and differentiation. Our objective was to establish an astroblastoma cell line to investigate the presence of astroblastic cells and cancer stem-like cells. The migratory and invasion abilities of the cells were quantified with invasion and migration assays and compared to a glioblastoma cell line. The presence of stem cells was detected with surface-marker analysis by using flow cytometry, and measuring the differentiation ability with a differentiation assay and the self-renewal capacity with a sphere-forming assay. These characteristics may determine whether this novel cell line is a model for astroblastomas that may have stem-cell characteristics. With this novel cell line, scientists can investigate the molecular pathways underlying astroblastomas and develop new therapeutic strategies for patients with these tumors. - Highlights: • An establishment of a novel astroblastoma cell line was proposed. • The presence of astroblastic cells and cancer stem-like cells was investigated. • The molecular pathways underlying astroblastomas may be investigated. • New therapeutic strategies for patients with astroblastoma may be developed.

60 APPLIED LIFE SCIENCES↗

Topological nodal-line fermions in spin-orbit metal PbTaSe2

Here we discuss how topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe 2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe 2 are not only protected by the reflection symmetry but also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems.

36 MATERIALS SCIENCE↗

Experimental realization of two-dimensional Dirac nodal line fermions in monolayer Cu 2 Si

Topological nodal line semimetals, a novel quantum state of materials, possess topologically nontrivial valence and conduction bands that touch at a line near the Fermi level. The exotic band structure can lead to various novel properties, such as long-range Coulomb interaction and flat Landau levels. Recently, topological nodal lines have been observed in several bulk materials, such as PtSn 4 , ZrSiS, TlTaSe 2 and PbTaSe 2 . However, in two-dimensional materials, experimental research on nodal line fermions is still lacking. Here, we report the discovery of two-dimensional Dirac nodal line fermions in monolayer Cu 2 Si based on combined theoretical calculations and angle-resolved photoemission spectroscopy measurements. The Dirac nodal lines in Cu 2 Si form two concentric loops centred around the Γ point and are protected by mirror reflection symmetry. In conclusion, our results establish Cu 2 Si as a platform to study the novel physical properties in two-dimensional Dirac materials and provide opportunities to realize high-speed low-dissipation devices.

36 MATERIALS SCIENCE↗

Ordering of self-assembled 5-nm-diameter poly(dimethylsiloxane) nanodots with sub-10 nm pitch using ultra-narrow electron-beam-drawn guide lines and three-dimensional control

We demonstrate the possibility of forming long-range ordered self-assembled arrays of 5-nm-diameter nanodots with pitch of 10 × 7.5 nm{sup 2} using guide line templates and low molecular weight (MW) (4700–1200 g/mol) poly(styrene)-poly(dimethylsiloxane) (PS-PDMS) for application in ultrahigh density patterned magnetic recording media. We propose a three-dimensional control which involves control of the height of the guide lines, the thickness of the PS-PDMS films, and the gap between the guide lines in order to produce 5-nm-diameter, sub-10 nm pitched nanodots with long-range order along the guide lines. Adopting a 13-nm-thick PS-PDMS film and 14-nm-high resist guide lines, the 5-nm-diameter and 10 × 7.5 nm{sup 2}-pitched self-assembled nanodots were ordered in 4–7 dot arrays with long-range order. The experimental results demonstrate that the method is suitable for the production of patterned media with magnetic recording densities of 8.6 Tbit/in.{sup 2} using low MW PS-PDMS and slim guide lines.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Highly accurate potential energy surface, dipole moment surface, rovibrational energy levels, and infrared line list for {sup 32}S{sup 16}O{sub 2} up to 8000 cm{sup −1}

A purely ab initio potential energy surface (PES) was refined with selected {sup 32}S{sup 16}O{sub 2} HITRAN data. Compared to HITRAN, the root-mean-squares error (σ{sub RMS}) for all J = 0–80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm{sup −1}. Combined with a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296 K and covers up to 8000 cm{sup −1}. Compared to the HITRAN and CDMS databases, the intensity agreement for most vibrational bands is better than 85%–90%. Our predictions for {sup 34}S{sup 16}O{sub 2} band origins, higher energy {sup 32}S{sup 16}O{sub 2} band origins and missing {sup 32}S{sup 16}O{sub 2} IR bands have been verified by most recent experiments and available HITRAN data. We conclude that the Ames-1 PES is able to predict {sup 32/34}S{sup 16}O{sub 2} band origins below 5500 cm{sup −1} with 0.01–0.03 cm{sup −1} uncertainties, and the Ames-296K line list provides continuous, reliable and accurate IR simulations. The K{sub a}-dependence of both line position and line intensity errors is discussed. The line list will greatly facilitate SO{sub 2} IR spectral experimental analysis, as well as elimination of SO{sub 2} lines in high-resolution astronomical observations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Interaction of ions, atoms, and small molecules with quantized vortex lines in superfluid {sup 4}He

The interaction of a number of impurities (H{sub 2}, Ag, Cu, Ag{sub 2}, Cu{sub 2}, Li, He{sub 3}{sup +}, He{sup *} ({sup 3}S), He{sub 2}{sup ∗} ({sup 3}Σ{sub u}), and e{sup −}) with quantized rectilinear vortex lines in superfluid {sup 4}He is calculated by using the Orsay-Trento density functional theory (DFT) method at 0 K. The Donnelly-Parks (DP) potential function binding ions to the vortex is combined with DFT data, yielding the impurity radius as well as the vortex line core parameter. The vortex core parameter at 0 K (0.74 Å) obtained either directly from the vortex line geometry or through the DP potential fitting is smaller than previously suggested but is compatible with the value obtained from re-analysis of the Rayfield-Reif experiment. All of the impurities have significantly higher binding energies to vortex lines below 1 K than the available thermal energy, where the thermally assisted escape process becomes exponentially negligible. Even at higher temperatures 1.5-2.0 K, the trapping times for larger metal clusters are sufficiently long that the previously observed metal nanowire assembly in superfluid helium can take place at vortex lines. The binding energy of the electron bubble is predicted to decrease as a function of both temperature and pressure, which allows adjusting the trap depth for either permanent trapping or to allow thermally assisted escape. Finally, a new scheme for determining the trapping of impurities on vortex lines by optical absorption spectroscopy is outlined and demonstrated for He{sup *}.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗