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Dielectronic recombination (DR) rate coefficients for carbon-like 40Ca14+ forming nitrogen-like 40Ca13+ have been measured using the electron–ion merged-beam technique at the heavy-ion storage ring CSRm at the Institute of Modern Physics in Lanzhou, China. The measured DR rate coefficients in the energy range from 0 to 92 eV cover most of the DR resonances associated with 2s22p2 → 2s22p2 and 2s22p2 → 2s2p3 core transitions (ΔN = 0). Theoretical calculations of the DR cross sections were carried out by using two different state-of-the-art atomic theoretical techniques, multiconfiguration Breit–Pauli (MCBP) code AUTOSTRUCTURE and relativistic configuration interaction code FAC, to compare with the experimental rate coefficients. The theoretical calculations agree with the experimental results at collision energy higher than 10 eV. However, significant discrepancies of resonance energies and strengths can be found at collision energy below 8 eV. Temperature-dependent plasma recombination rate coefficients were derived from the measured DR rate coefficients in the energy range from 0.1 to 1000 eV and compared with the recommended atomic data from the literature. The theoretical data of Gu et al. and Zatsarinny et al. are 30% lower than the experimental results at the temperatures of photoionized plasmas, but have a very good agreement at the temperatures of collisionally ionized plasmas. Other previously published theoretical data of Jacobs et al. and Mazzotta et al. by using Burgess formula and LS-coupling calculations significantly underestimate the plasma rate coefficients in the low temperature range. The present results comprise a set of benchmark data suitable for astrophysical modeling. [ABSTRACT FROM AUTHOR]

Summary: Background: Novel treatments with superior benefit‐risk profiles are needed to improve the long‐term prognosis of patients with inflammatory bowel disease (IBD). Etrolizumab—a monoclonal antibody that specifically targets β7 integrins—is currently under phase III clinical evaluation in IBD. Aim: This review summarises the available pharmacological and pharmacokinetic/pharmacodynamic data for etrolizumab to provide a comprehensive understanding of its mechanism of action (MOA) and pharmacological effects. Methods: Published and internal unpublished data from nonclinical and clinical studies with etrolizumab are reviewed. Results: Etrolizumab exerts its effect via a unique dual MOA that inhibits both leucocyte trafficking to the intestinal mucosa and retention within the intestinal epithelial layer. The gut‐selectivity of etrolizumab results from its specific targeting of the β7 subunit of α4β7 and αEβ7 integrins. Etrolizumab does not bind to α4β1 integrin, which mediates lymphocyte trafficking to tissues including the central nervous system, a characteristic underlying its favourable safety with regard to progressive multifocal leucoencephalopathy. Phase I/II studies in patients with ulcerative colitis (UC) showed linear pharmacokinetics when etrolizumab was administered subcutaneously at 100 mg or higher once every 4 weeks. This dose was sufficient to enable full β7 receptor occupancy in both blood and intestinal tissues of patients with moderate to severe UC. The phase II study results also suggested that patients with elevated intestinal expression of αE integrin may have an increased likelihood of clinical remission in response to etrolizumab treatment. Conclusion: Etrolizumab is a gut‐selective, anti‐β7 integrin monoclonal antibody that may have therapeutic potential for the treatment of IBD. [ABSTRACT FROM AUTHOR]

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A modified algorithm for X-ray dynamical diffraction theory is presented for curved boundary crystals and a detailed description of the numerical procedure is given. The simulated and experimental results both show an anomalous focusing behavior in a curved multi-plate crystal cavity of silicon under the back-diffraction condition at a photon energy of 14.4388 keV. The focusing effects are analyzed, within the framework of the dynamical theory of X-ray diffraction, from the excitation of the dispersion surface and modification of the index of refraction with respect to the non-plane-parallel boundaries of a curved crystal cavity. [ABSTRACT FROM AUTHOR]

Studies have shown that the 577R alíele of cc- actinin-3 (ACTN3) is more prevalent in sprint athletes than in the general population or in endurance athletes. We examined the distribution of ACTN3 R577X (rs 1815739) genotypes and alíeles in the Taiwanese general population (603) and in elite sprint swimmers who had participated in international/national events (168). Additionally, 50 pre-adolescent (age 11-13 years) male students and 38 adult males who completed 12-weeks of swimming training, were included in the present study. We found that the frequencies of the R alíele were significantly higher in female international sprint swimmers (67.6%) than in national sprint swimmers (50.0%) or in the general population (53.7%). Th 25-m performance was significantly improved across the genotypes after swimming training among the pre-adolescent males but not among the adult males. In addition, pre-adolescents with the RR genotype had the best performance both before and after training although not statistically significant. In conclusion, the frequencies of ACTN3 577R alíele were significantly higher in female international sprint swimmers than among national sprint swimmers or the general population. Furthermore, male pre-adolescents with either the ACTN3 RX or XX genotype showed a greater improvement in 25-meter swimming performance than those with the RR genotype. [ABSTRACT FROM AUTHOR]

Volociximab is a chimeric IgG4 that is being developed as a novel first-in-class anti-angiogenic, α5β1 integrin inhibitor for the treatment of solid tumors. A mechanism-based pharmacokinetic (PK)/pharmacodynamic (PD) model was developed to investigate the dynamic interaction between volociximab concentrations and free monocyte α5β1 integrin levels in cancer patients. Twenty-one cancer patients from six dose cohorts (0.5, 1.0, 2.5, 5.0, 10, and 15 mg/kg) were included in the analysis. The fully integrated receptor-binding PK/PD model was developed and fit simultaneously to the PK/PD data. A Monte-Carlo parametric expectation-maximization method implement in S-ADAPT program was used to obtain estimates of population parameters and inter- and intra-subject variability. The PK/PD time profiles were well described by the model and the parameters were estimated with good precision. The model was used to simulate PK/PD time profiles for multiple dose regimens at various dose levels, and the results suggested that the monocyte α5β1 integrin binding was saturated (≤5% free) at week 16 in the majority of patients treated with volociximab doses ≥10 mg/kg IV every 2 weeks. The developed model is useful for anticipating the drug exposures and extent of volociximab binding to peripheral monocyte α5β1 integrin in untested regimens and for optimizing the design of future clinical trials. [ABSTRACT FROM AUTHOR]

Nanocrystalline CeO2 samples were prepared via precipitation from aqueous cerium(IV) sulfate solution under a controlled pH. After being subjected to calcination at various temperatures to yield different particle sizes, the local structure around Ce atom was investigated by using EXAFS spectroscopy at Ce K-edge. The first shell Ce&z.sbnd;O distance was found to be slightly shorter with small CeO2 particles, indicating a contraction of the lattice. There exists a significant growth in coordination number of the second cell Ce&z.sbnd;Ce when the particle size became larger. In terms of Debye–Waller factor (σ2), the first three coordination shells showed a consistent trend, i.e. the degree of disorder increases with reduced particle size. Moreover, σ2 of the second shell was found to be smaller than that of the first shell for all samples. [ABSTRACT FROM AUTHOR]

We report on the trapping of 14 keV photons in periods of 1.11–1.67 ps by the 12 4 0 backdiffraction in two- and multiplate silicon single-crystal cavities of a few hundred micrometer size. The formation of standing waves inside the cavities ensures better coherence for the x rays. We anticipate that the transmitted x rays through this type of cavities can be used as a quasicoherent x-ray source for probing the dynamic structures of solids, liquids, and biological substances. [ABSTRACT FROM AUTHOR]

Cubic phase yttrium-doped HfO2 (YDH) ultrathin films were grown on Si (111) substrates by molecular beam epitaxy. Thorough structural and morphological investigations by x-ray scattering and transmission electron microscopy reveal that the YDH thin films are epitaxially grown on the Si substrates with (111)YDH∥(111)Si and [101]YDH∥[110]Si. The interface between YDH and Si is atomistic sharp and free of interfacial layer. We have also determined the yttrium content of YDH films to be 19% by using anomalous x-ray diffraction (AXD) across Y k edge and angle resolved x-ray photoelectron spectroscopy (AR-XPS). The agreement between the AXD and AR-XPS results manifests that the incorporated Y atoms homogeneously substitute Hf atoms in the crystalline lattice and form a substitutional solid solution. [ABSTRACT FROM AUTHOR]

The authors report a general methodology for probing the depth profile of alloying extent and composition in bimetallic nanoparticles (NPs) by a combined in situ x-ray absorption spectroscopy (XAS) and electrochemical strategy. The XAS results of Pt-richcore–Ru-richshell NPs during methanol electro-oxidation revealed that the alloying extent of Pt (JPt) and Ru (JRu) is higher in the core region compared to those in the shell region. An average decrease in the JPt and JRu is observed when the cluster undergoes reduction. By controlling the cluster oxidation degree it is possible to probe the depth profile of the alloying extent in bimetallic NPs. [ABSTRACT FROM AUTHOR]

A generic x-ray diffraction method, using three-wave Bragg-surface diffraction, is developed to measure strains at the interface of molecular beam epitaxial Au/GaAs(001), where grazing-incidence diffraction cannot be applied due to the difference in refractive index between Au and GaAs. Changes in diffraction images of the surface reflection (1-13) of GaAs(006)/(1-13) three-wave Bragg-surface diffraction and the (-1-13) of GaAs(006)/(-1-13) at different azimuth and Bragg angles give the depth penetration of 2 Å resolution and variations of lattice constant, -49%, -27%, and 2%, along the surface normal [001] and in-plane directions [-1-10] and [1-10] within the depths of 18, 72, and 72 Å, respectively. [ABSTRACT FROM AUTHOR]

The electronic and atomic structures of quasi-one-dimensional blue bronze K0.3MoO3 were investigated by polarization-dependent O K-edge x-ray absorption near-edge structure (XANES) and Mo K-edge extended x-ray absorption fine structure (EXAFS) measurements at various temperature and applied voltages. The O K-edge XANES spectra suggest that the number of unoccupied O 2p–Mo 4d hybridized states increases and decreases with temperature, respectively, below and above a critical temperature of 180 K. The along b-axis electric current measurements show a threshold applied voltage, beyond which the current increases rapidly. The Mo K-edge EXAFS measurements show that the Mo–O bond lengths are insensitive to the temperature even beyond 180 K. [ABSTRACT FROM AUTHOR]

In this study, a distributed charge storage with GeO2 nanodots is demonstrated. The mean size and aerial density of the nanodots embedded in SiO2 are estimated to be about 5.5 nm and 4.3×1011 cm-2, respectively. The composition of the dots is also confirmed to be GeO2 by x-ray absorption near-edge structure analyses. A significant memory effect is observed through the electrical measurements. Under the low voltage operation of 5 V, the memory window is estimated to ∼0.45 V. Also, a physical model is proposed to demonstrate the charge storage effect through the interfacial traps of GeO2 nanodots. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Dielectronic recombination (DR) rate coefficients for carbon-like 40Ca14+ forming nitrogen-like 40Ca13+ have been measured using the electron–ion merged-beam technique at the heavy-ion storage ring CSRm at the Institute of Modern Physics in Lanzhou, China. The measured DR rate coefficients in the energy range from 0 to 92 eV cover most of the DR resonances associated with 2s22p2 → 2s22p2 and 2s22p2 → 2s2p3 core transitions (ΔN = 0). Theoretical calculations of the DR cross sections were carried out by using two different state-of-the-art atomic theoretical techniques, multiconfiguration Breit–Pauli (MCBP) code AUTOSTRUCTURE and relativistic configuration interaction code FAC, to compare with the experimental rate coefficients. The theoretical calculations agree with the experimental results at collision energy higher than 10 eV. However, significant discrepancies of resonance energies and strengths can be found at collision energy below 8 eV. Temperature-dependent plasma recombination rate coefficients were derived from the measured DR rate coefficients in the energy range from 0.1 to 1000 eV and compared with the recommended atomic data from the literature. The theoretical data of Gu et al. and Zatsarinny et al. are 30% lower than the experimental results at the temperatures of photoionized plasmas, but have a very good agreement at the temperatures of collisionally ionized plasmas. Other previously published theoretical data of Jacobs et al. and Mazzotta et al. by using Burgess formula and LS-coupling calculations significantly underestimate the plasma rate coefficients in the low temperature range. The present results comprise a set of benchmark data suitable for astrophysical modeling. [ABSTRACT FROM AUTHOR]

Abstract: Electromagnetic transitions within nuclei reflect specific aspects of nuclear structure. This is particularly true for metastable excited states, or isomers, like 178Hf m2 ( years, excitation energy 2446 keV). The interaction of external radiation with isomers can be used to study atomic and nuclear properties and, perhaps, to induce a release of the stored energy. Some experiments indicated that low-energy photons near the L3 edge (9.561 keV) of hafnium could cause this to occur for 178Hf m2, but the lack of a viable physical model and null experiments by other groups have left these claims in doubt. The present work describes a new experiment to examine this process by closely duplicating the irradiation conditions in positive studies, but using a more advanced multi-detector γ array. No support for an induced depletion of 178Hf m2 by low-energy photons was obtained, with an upper limit for the integral cross section that is eight orders-of-magnitude below the reported value. [Copyright &y& Elsevier]

We present a structural investigation of self-assembled InGaAs quantum dots on GaAs(0 0 1) substrates grown by molecular-beam epitaxy. The grazing incidence X-ray scattering measurements were performed at BL17B of Taiwan Light Source and BL12B2 of SPring-8. The strain field, composition distribution, and shape of the dots are determined. We found that In concentration was less than the nominal composition, 50% near the dot/substrate interface and exceeded 50% near the top of the dots, indicating In surface segregation. In addition, the relation between the strain and the composition did not obey Vegard’s law. [Copyright &y& Elsevier]

The electronic and atomic structures of quasi-one-dimensional blue bronze K0.3MoO3 were investigated by polarization-dependent O K-edge x-ray absorption near-edge structure (XANES) and Mo K-edge extended x-ray absorption fine structure (EXAFS) measurements at various temperature and applied voltages. The O K-edge XANES spectra suggest that the number of unoccupied O 2p–Mo 4d hybridized states increases and decreases with temperature, respectively, below and above a critical temperature of 180 K. The along b-axis electric current measurements show a threshold applied voltage, beyond which the current increases rapidly. The Mo K-edge EXAFS measurements show that the Mo–O bond lengths are insensitive to the temperature even beyond 180 K. [ABSTRACT FROM AUTHOR]

Daclizumab is a humanized monoclonal antibody that prevents interleukin-2 (IL-2) binding to CD25, blocking IL-2 signaling by cells that require high-affinity IL-2 receptors to mediate IL-2 signaling. The phase 2a CHOICE study evaluating daclizumab as a treatment for multiple sclerosis (MS) included longitudinal analysis of activated T cell counts. Whereas an exposure-dependent relationship was observed between daclizumab and reductions in HLA-DR(+)-activated T cells, a similar relationship was not observed for reductions in CD25 levels. The objective of this report is to determine the mechanism by which daclizumab reduces CD25 levels on peripheral blood mononuclear cells (PBMCs) using cytometric techniques. Daclizumab reduced T cell CD25 levels through a mechanism that required the daclizumab-Fc domain interaction with Fc receptors (FcR) on monocytes, but not on natural killer (NK) cells, and was unrelated to internalization or cell killing. Activated CD4(+) T cells and FoxP3(+) Treg cells showed evidence of trogocytosis of the CD25 antigen in the presence of monocytes. A daclizumab variant that retained affinity for CD25 but lacked FcR binding did not induce trogocytosis and was significantly less potent as an inhibitor of IL-2-induced proliferation of PBMCs. In conclusion, Daclizumab-induced monocyte-mediated trogocytosis of CD25 from T cells appears to be an additional mechanism contributing to daclizumab inhibition of IL-2 signaling.

A modified algorithm for X-ray dynamical diffraction theory is presented for curved boundary crystals and a detailed description of the numerical procedure is given. The simulated and experimental results both show an anomalous focusing behavior in a curved multi-plate crystal cavity of silicon under the (12,4,0) back-diffraction condition at a photon energy of 14.4388 keV. The focusing effects are analyzed, within the framework of the dynamical theory of X-ray diffraction, from the excitation of the dispersion surface and modification of the index of refraction with respect to the non-plane-parallel boundaries of a curved crystal cavity.

Unusual x-ray focusing effect is reported for parabolic curved multi-plate x-ray crystal cavities of silicon consisting of compound refractive lenses (CRL). The transmitted beam of the (12 4 0) back reflection near 14.4388 keV from these monolithic silicon crystal devices exhibits extraordinary focusing enhancement, such that the focal length is reduced by as much as 18% for 2-beam and 56% for 24-beam diffraction from the curved crystal cavity. This effect is attributed to the presence of the involved Bragg diffractions, in which the wavevector of the transmitted beam is bent further when traversing several curved crystal surfaces.

X-ray back diffraction from monolithic two silicon crystal plates of 25-150 microm thickness and a 40-150 microm gap using synchrotron radiation of energy resolution DeltaE = 0.36 meV at 14.4388 keV clearly show resonance fringes inside the energy gap and the total-reflection range for the (12 4 0) reflection. This cavity resonance results from the coherent interaction between the x-ray wave fields generated by the two plates with a gap smaller than the x-ray coherence length. This finding opens up new opportunities for high-resolution and phase-contrast x-ray studies, and may lead to new developments in x-ray optics.

The authors investigated the possibility that, in interview-based case-control studies, controls are more likely than cases to underreport a history of induced abortion. A case-control study was conducted in White women under 45 years of age who had given birth in Washington State during 1984-1994. The cases were women in three metropolitan counties of Washington State diagnosed with invasive breast cancer during 1984-1994; controls were selected through random digit dialing. A history of induced abortion among study participants was compared between interview data and information collected on the birth record of the last child to whom they gave birth (225 cases, 303 controls). Among women with a prior induced abortion recorded on the birth record, 14.0% of the 43 cases and 14.9% of the 47 controls did not report an induced abortion at interview (difference = -0.9%, 95% confidence interval of the difference: -15, 14). The authors' data do not suggest that controls are more reluctant to report a history of induced abortion than are women with breast cancer.

A UHV surface X-ray scattering system has been constructed at the SRRC, providing users with a state-of-the-art system for performing X-ray scattering studies of two-dimensional crystallography, in situ growth mechanisms as well as phase transitions of surfaces and interfaces. A study of the phase transition of the Si(001) reconstructed surface was conducted to commission both the scattering system and the SRRC X-ray beamline. The detailed design and performance of the SRRC surface X-ray scattering system together with the results of the Si(001) study are presented.

Six patients suffering from ovarian sex cord tumor with annular tubules (SCTAT) were reported in this article with special reference to the clinical features, histological characteristics, sex hormone profile, and management of disease. SCTAT was documented to be a estrogen-progesterone-secreting tumor based on the observations of glandular atrophy and decidual change of stroma in the endometrium and assays of steroid hormone. Menometrorrhagia followed by persistent amenorrhea and pelvic mass were presented as important clinical features. This tumor was considered as a tumor with low-grade malignancy, and retroperitoneal lymphatic metastasis was thought to be an important pathway of spread. Unilateral salpingo-oophorectomy together with ipsilateral pelvic and para-aortic lymphadenectomy were suggested as an effective treatment for SCTAT. Radiotherapy can be used for local recurrence and distant metastases.