1,015 research outputs found
Epitaxial growth of iron iodide films on Fe(l10)
The interaction of iodine vapor on an Fe(110) single crystal surface at room temperature has been investigated primarily through the use of LEED and UPS. Both a series of chemisorbed overlayers and an epitaxial iodide layer are observed. Iodide formation proceeds through an island growth mechanism with the iodide basal plane parallel to the Fe(110) surface. Evidence is presented that the defects introduced on the surface during argon ion sputtering may be important as nucleation sites for iodide growth. The results are compared with the results of previous studies
Epitaxial growth of iron iodide films on Fe(l10)
The interaction of iodine vapor on an Fe(110) single crystal surface at room temperature has been investigated primarily through the use of LEED and UPS. Both a series of chemisorbed overlayers and an epitaxial iodide layer are observed. Iodide formation proceeds through an island growth mechanism with the iodide basal plane parallel to the Fe(110) surface. Evidence is presented that the defects introduced on the surface during argon ion sputtering may be important as nucleation sites for iodide growth. The results are compared with the results of previous studies
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Evaluation of fall chinook salmon spawning adjacent to the In-Situ Redox Manipulation treatability test site, Hanford Site, Washington
The In Situ Redox Manipulation (ISRM) experiment is being evaluated as a potential method to remove contaminants from groundwater adjacent to the Columbia River near the 100-D Area. The ISRM experiment involves using sodium dithionate (Na{sub 2}O{sub 6}S{sub 2}) to precipitate chromate from the groundwater. The treatment will likely create anoxic conditions in the groundwater down-gradient of the ISRM treatability test site; however, the spatial extent of this anoxic plume is not exactly known. Surveys were conducted in November 1997, following the peak spawning of fall chinook salmon. Aerial surveys documented 210 redds (spawning nests) near the downstream island in locations consistent with previous surveys. Neither aerial nor underwater surveys documented fall chinook spawning in the vicinity of the ISRM treatability test site. Based on measurements of depth, velocity, and substrate, less than 1% of the study area contained suitable fall chinook salmon spawning habitat, indicating low potential for fall chinook salmon to spawn in the vicinity of the ISRM experiment
Hospitalization and Mortality Outcomes among Childhood Cancer Survivors by Race, Ethnicity, and Time since Diagnosis
Importance: Cancer outcomes are relatively poor in adults who belong to minoritized racial and ethnic groups. Survival and long-term outcomes by race and ethnicity in individuals with childhood cancers are less studied. Objective: To evaluate survival and hospitalization among American Indian and Alaska Native, Asian, Black, and Hispanic children compared with non-Hispanic White children with cancer. Design, Setting, and Participants: This cohort study evaluated all individuals born in Washington State who were younger than 20 years (hereafter referred to as children) and had been diagnosed with cancer during 1987 to 2012, with follow-up ranging from 1 to 27 years. The data subset was built in 2019, and statistical analyses were completed in January 2022. Exposures: Race and ethnicity. Main Outcomes and Measures: Mortality and hospitalization events for all other racial and ethnic groups relative to non-Hispanic White children estimated by Cox proportional hazards regressions for the first 5 years after diagnosis and among cancer survivors 5 or more years after diagnosis. Results: A total of 4222 children (mean [SD] age, 8.4 [6.4] years; 2199 [52.1%] male; 113 American Indian and Alaska Native [2.7%], 311 Asian [7.4%], 196 Black [4.6%], 387 Hispanic [9.2%], and 3215 non-Hispanic White [76.1%]) with cancer diagnosed at younger than 20 years during 1987 to 2012 were included. Mortality was similar across all groups. Compared with non-Hispanic White survivors at less than 5 years after diagnosis, there were no greatly increased hazard ratios (HRs) for hospitalization. Among survivors at 5 or more years after diagnosis, hospitalization HRs were 1.7 (95% CI, 1.0-3.0) for American Indian and Alaska Native survivors and 1.5 (95% CI, 0.9-2.4) for Black survivors. Significantly increased HRs among Hispanic children were observed for infection-related (HR, 1.4; 95% CI, 1.2-1.6), endocrine-related (HR, 1.3; 95% CI, 1.1-1.6), hematologic-related (HR, 1.3; 95% CI, 1.1-1.5), respiratory-related (HR, 1.3; 95% CI, 1.0-1.5), and digestive-related (HR, 1.2; 95% CI, 1.0-1.5) conditions. American Indian and Alaskan Native children had increased HRs for infection-related (HR, 2.3; 95% CI, 1.2-4.5), hematologic-related (HR, 3.0; 95% CI, 1.4-6.5), and digestive-related (HR, 2.6; 95% CI, 1.3-5.4) conditions. Both American Indian and Alaska Native (HR, 3.6; 95% CI, 1.4-9.0) and Black (HR, 2.5; 95% CI, 1.2-5.5) children had increased mental health-related hospitalizations and death. Conclusions and Relevance: In this cohort study, disproportionately increased long-term risks of hospitalization for physical and mental conditions may have contributed to worse outcomes by race. A key component to bridging the morbidity gap by race is improved understanding of reasons for greater cause-specific hospitalizations in some groups, with development of culturally appropriate intervention strategies.
High Energy QCD: Stringy Picture from Hidden Integrability
We discuss the stringy properties of high-energy QCD using its hidden
integrability in the Regge limit and on the light-cone. It is shown that
multi-colour QCD in the Regge limit belongs to the same universality class as
superconformal =2 SUSY YM with at the strong coupling
orbifold point. The analogy with integrable structure governing the low energy
sector of =2 SUSY gauge theories is used to develop the brane picture
for the Regge limit. In this picture the scattering process is described by a
single M2 brane wrapped around the spectral curve of the integrable spin chain
and unifying hadrons and reggeized gluons involved in the process. New
quasiclassical quantization conditions for the complex higher integrals of
motion are suggested which are consistent with the duality of the
multi-reggeon spectrum. The derivation of the anomalous dimensions of the
lowest twist operators is formulated in terms of the Riemann surfacesComment: 37 pages, 3 figure
Strings in Homogeneous Background Spacetimes
The string equations of motion for some homogeneous (Kantowski-Sachs, Bianchi
I and Bianchi IX) background spacetimes are given, and solved explicitly in
some simple cases. This is motivated by the recent developments in string
cosmology, where it has been shown that, under certain circumstances, such
spacetimes appear as string-vacua.
Both tensile and null strings are considered. Generally, it is much simpler
to solve for the null strings since then we deal with the null geodesic
equations of General Relativity plus some additional constraints.
We consider in detail an ansatz corresponding to circular strings, and we
discuss the possibility of using an elliptic-shape string ansatz in the case of
homogeneous (but anisotropic) backgrounds.Comment: 25 pages, REVTE
Neutrino-Deuteron Scattering in Effective Field Theory at Next-to-Next-to Leading Order
We study the four channels associated with neutrino-deuteron breakup
reactions at next-to-next to leading order in effective field theory. We find
that the total cross-section is indeed converging for neutrino energies up to
20 MeV, and thus our calculations can provide constraints on theoretical
uncertainties for the Sudbury Neutrino Observatory. We stress the importance of
a direct experimental measurement to high precision in at least one channel, in
order to fix an axial two-body counterterm.Comment: 32 pages, 14 figures (eps
Specific Heat of Liquid Helium in Zero Gravity very near the Lambda Point
We report the details and revised analysis of an experiment to measure the
specific heat of helium with subnanokelvin temperature resolution near the
lambda point. The measurements were made at the vapor pressure spanning the
region from 22 mK below the superfluid transition to 4 uK above. The experiment
was performed in earth orbit to reduce the rounding of the transition caused by
gravitationally induced pressure gradients on earth. Specific heat measurements
were made deep in the asymptotic region to within 2 nK of the transition. No
evidence of rounding was found to this resolution. The optimum value of the
critical exponent describing the specific heat singularity was found to be a =
-0.0127+ - 0.0003. This is bracketed by two recent estimates based on
renormalization group techniques, but is slightly outside the range of the
error of the most recent result. The ratio of the coefficients of the leading
order singularity on the two sides of the transition is A+/A- =1.053+ - 0.002,
which agrees well with a recent estimate. By combining the specific heat and
superfluid density exponents a test of the Josephson scaling relation can be
made. Excellent agreement is found based on high precision measurements of the
superfluid density made elsewhere. These results represent the most precise
tests of theoretical predictions for critical phenomena to date.Comment: 27 Pages, 20 Figure
Therapeutic drug monitoring of oral targeted antineoplastic drugs
Purpose: This review provides an overview of the current challenges in oral targeted antineoplastic drug (OAD) dosing and outlines the unexploited value of therapeutic drug monitoring (TDM). Factors influencing the pharmacokinetic exposure in OAD therapy are depicted together with an overview of different TDM approaches. Finally, current evidence for TDM for all approved OADs is reviewed. Methods: A comprehensive literature search (covering literature published until April 2020), including primary and secondary scientific literature on pharmacokinetics and dose individualisation strategies for OADs, together with US FDA Clinical Pharmacology and Biopharmaceutics Reviews and the Committee for Medicinal Products for Human Use European Public Assessment Reports was conducted. Results: OADs are highly potent drugs, which have substantially changed treatment options for cancer patients. Nevertheless, high pharmacokinetic variability and low treatment adherence are risk factors for treatment failure. TDM is a powerful tool to individualise drug dosing, ensure drug concentrations within the therapeutic window and increase treatment success rates. After reviewing the literature for 71 approved OADs, we show that exposure-response and/or exposure-toxicity relationships have been established for the majority. Moreover, TDM has been proven to be feasible for individualised dosing of abiraterone, everolimus, imatinib, pazopanib, sunitinib and tamoxifen in prospective studies. There is a lack of experience in how to best implement TDM as part of clinical routine in OAD cancer therapy. Conclusion: Sub-therapeutic concentrations and severe adverse events are current challenges in OAD treatment, which can both be addressed by the application of TDM-guided dosing, ensuring concentrations within the therapeutic window
Measurement of the neutron magnetic form factor from inclusive quasielastic scattering of polarized electrons from polarized 3He
We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized 3He target. The neutron magnetic form factor GMn has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. Our determination of GMn at Q2=0.19 (GeV/c)2 agrees with the dipole parametrization. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering
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