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In this work, the adsorption height of Ag adatoms on the Fe3O4(001) surface after exposure to CO was determined using normal incidence x-ray standing waves. The Ag adatoms bound to CO (Ag1 CO) are found to be pulled out of the surface to an adsorption height of 1.15 Å ± 0.08 Å, compared to the previously measured height of 0.96 Å ± 0.03 Å for bare Ag adatoms and clusters. Utilizing DFT+vdW+U calculations with the substrate unit cell dimension fixed to the experimental value, the predicted adsorption height for Ag1 CO was 1.16 Å, in remarkably good agreement with the experimental results.

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The normal incidence X-ray standing wave (NIXSW) technique has been used to follow the evolution of the adsorption geometry of Ni adatoms on the Fe3O4(001)-(√2 × âˆš2)R45° surface as a function of temperature. Two primary surface region sites are identified: a bulk-continuation tetrahedral site and a sub-surface octahedral site, the latter site being preferred at higher annealing temperatures. The ease of incorporation is linked to the presence of subsurface cation vacancies in the (√2 × âˆš2)R45° reconstruction and is consistent with the preference for octahedral coordination observed in the spinel compound NiFe2O4.

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Two experiments were conducted to study effects of dietary insoluble fiber (IF) on digestive enzyme function in layer poultry. In Experiment 1, 8 wk old pullets were fed a control diet (Group C) or a diet (Group IF) supplemented with 1% IF (Arbocel RC). After 5 wk, 6 pullets per group were killed and organ samples collected. The remaining pullets in Group C were divided into two groups: half were fed the control diet (Group C) and half were given the IF diet (Group C-IF). Similarly, half the pullets in Group IF continued on the IF diet (Group IF) and half on the control diet (Group IF-C). At 10 wk, organ samples were collected. BW at wk 5 (IF, 1364.8 g; C, 1342.9 g) and 10 wk (IF, 1678.1 g; IF-C, 1630.5 g; C-IF, 1617.1 g; C, 1580.4 g) were not different. At wk 5, the relative proventricular weight (0.41 g/100 g BW) and activities of pepsin (75.3 pepsin units/g proventriculus/min) and pancreatic general proteolytic activity (GP) (122.9 µmol tyrosine produced/g tissue) were greater (P < 0.05) than those of Group C (proventricular relative weight, 0.36; pepsin activity, 70.6; GP activity, 94.3). At wk 10, relative weights of liver and gizzard of Group IF were heavier (P < 0.05) than other treatments; activities of pepsin, GP, trypsin and chymotrypsin of IF pullets were significantly greater than other treatments as was mRNA expression for pepsinogens A (25.9 vs. 22.9) and C (13.1 vs. 10.8). In Experiment 2, 19 wk old hens were fed a control diet or a diet containing 0.8% IF (Arbocel RC) for 12 wk. Final BW after 12 wk was not different (IF, 1919.4 g; C, 1902.1 g). Pancreatic GP activity was greater (P < 0.05) in Group IF hens than Group C at wk 12 (122.2 vs. 97.0 µmol tyrosine released/min/g tissue)) as was relative gizzard weight (1.32 vs 1.10 g/100 g BW). The significantly improved digestive organ weights and enzyme activities in IF pullets may contribute to an improvement in feed utilization.

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Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics, and drug delivery. The surface or material interface can be performance-limiting in these applications, so it is vital to determine accurate atomic-scale structures for iron oxides and understand why they form. Using a combination of quantitative low-energy electron diffraction, scanning tunneling microscopy, and density functional theory calculations, we show that an ordered array of subsurface iron vacancies and interstitials underlies the well-known (√2 × âˆš2)R45° reconstruction of Fe3O4(001). This hitherto unobserved stabilization mechanism occurs because the iron oxides prefer to redistribute cations in the lattice in response to oxidizing or reducing environments. Many other metal oxides also achieve stoichiometry variation in this way, so such surface structures are likely commonplace.

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Complementary but independent medium-energy and low-energy ion scattering studies of the (0001) surfaces of V(2)O(3) films grown on Pd(111), Au(111) and Cu(3)Au(100) reveal a reconstructed full O(3)-layer termination creating a VO(2) surface trilayer. This structure is fully consistent with previous calculations based on thermodynamic equilibrium at the surface during growth, but contrasts with previous suggestions that the surface termination comprises a complete monolayer of vanadyl (V=O) species.

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The energy spectrum associated with scattering of 100 keV H+ ions from the outermost few atomic layers of Cu(111) in different scattering geometries provides direct evidence of trajectory-dependent electronic energy loss. Theoretical simulations, combining standard Monte Carlo calculations of the elastic scattering trajectories with coupled-channel calculations to describe inner-shell ionization and excitation as a function of impact parameter, reproduce the effects well and provide a means for far more complete analysis of medium-energy ion scattering data.

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1. An experiment was conducted to investigate the influence of dietary casein phosphopeptides and 25-hydroxycholecalciferol on the incidence of tibial dyschondroplasia (TD) in 14-d-old commercial broiler chickens. 2. Three hundred and twenty broiler chicks (one day old) were randomly allocated to one of 4 dietary treatments. A standard broiler diet was used as the control with the three experimental treatments receiving the control diet supplemented with 10 g casein phosphopeptide/kg, 14 g casein phosphopeptide/kg or 69 microg 25-hydroxycholecalciferol/kg. 3. Those birds fed the diets supplemented with 14g casein phosphopeptide/kg or 25-hydroxycholecalciferol had a lower incidence of TD than both the control and 10g casein phosphopeptide/kg treatments when assessed grossly. 4. The body weight of birds fed the 10 g casein phosphopeptide/kg diet or the 25-hydroxycholecalciferol diet was higher than birds fed the control diet. Although not significant, the body weight of birds fed the 14 g casein phosphopeptide/kg diet was also greater than the control birds. 5. The current experiment demonstrated that both casein phosphopeptide and 25-hydroxycholecalciferol can reduce the incidence of TD in the young broiler chicken. More research is required to explain the unexpected increase in body weight described above.

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The catabolite activator protein (CAP) makes no direct contact with the consensus base-pair T:A at position 6 of the DNA half-site 5'-A(1)A(2)A(3)T(4)G(5)T(6)G(7)A(8)T(9)C(10)T(11)-3' but, nevertheless, exhibits strong specificity for T:A at position 6. Binding of CAP results in formation of a sharp DNA kink, with a roll angle of approximately 40 degrees and a twist angle of approximately 20 degrees, between positions 6 and 7 of the DNA half-site. The consensus base-pair T:A at position 6 and the consensus base-pair G:C at position 7 form a T:A/G:C step, which is known to be associated with DNA flexibility. It has been proposed that specificity for T:A at position 6 is a consequence of formation of the DNA kink between positions 6 and 7, and of effects of the T:A(6)/G:C(7) step on the geometry of DNA kinking, or the energetics of DNA kinking. In this work, we determine crystallographic structures of CAP-DNA complexes having the consensus base-pair T:A at position 6 or the non-consensus base-pair C:G at position 6. We show that complexes containing T:A or C:G at position 6 exhibit similar overall DNA bend angles and local geometries of DNA kinking. We infer that indirect readout in this system does not involve differences in the geometry of DNA kinking but, rather, solely differences in the energetics of DNA kinking. We further infer that the main determinant of DNA conformation in this system is protein-DNA interaction, and not DNA sequence.

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BACKGROUND: Maternal domestic violence (MDV) screening by pediatricians is not well-studied. Objectives. To determine the practicality and dynamics of routine MDV screening in a private pediatric office and to determine the rate of MDV in Upper Cape Cod, Massachusetts. SETTING: A 3-pediatrician, private pediatric office in Falmouth, Massachusetts. PARTICIPANTS: Mothers of children aged 1 month to 10 years scheduled to undergo a well-child visit between February 7 and July 7, 2000. INTERVENTION: Completion of an 11-item questionnaire related to violence. RESULTS: Seven hundred sixty-six families were scheduled for well visits. Five hundred ninety-two eligible mothers presented to the office. Five hundred fifty-three completed questionnaires were returned (71.2%). The rate of MDV was 2.5% in current relationships (95% confidence interval [CI]: 1.4-4.3), 14.7% in past relationships (95% CI: 11.9-18.0), and 16.5% overall (95% CI: 13.5-19.9). Increased incidence of MDV was associated with the following variables: 1) harm to a child (odds ratio [OR]: 57.3, 95% CI: 7.3-1232.4), 2) being in a relationship other than a first marriage (OR: 4.6, 95% CI: 2.7-7.8), 3) having been previously asked about MDV (OR: 3.5, 95% CI: 2.1-6.1), 4) having 4 or more children (OR: 3.1, 95% CI: 1.6-6.1), 5) Women, Infants, and Children's program eligibility (OR: 3.0, 95% CI: 1.8-5.0), 6) having public insurance (ie, Medicaid or Children's Medical Security Plan) (OR: 2.2, 95% CI: 1.3-3.7), 7) a history of failure to present for a scheduled well-child visit (no-show; OR: 2.0, 95% CI: 1.0-4.2) and 8) anonymous questionnaire completion (OR: 1.7, 95% CI: 1.0-2.9). Thirty-two and one-half percent (32/91, 95% CI: 25.6-46.0) of mothers with a history of MDV recall having previously been asked about this by a health professional, compared with 16.9% overall (93/551, 95% CI: 13.9-20.3). Eighty-two and eight tenths (82.8) percent (457/552, 95% CI: 79.3-85.8) of mothers favored pediatricians asking about MDV. DISCUSSION: This information was gathered within the context of normal work hours in a busy office. No additional staff were required. Hence, routine MDV screening appears feasible. The results suggest that a documented history of child abuse in a family makes it very likely that the mother has also been abused. However, child abuse among abused mothers is probably underreported. Furthermore, because most mothers favor domestic violence screening, concerns about lack of acceptance of maternal screening at pediatric visits seem to be unfounded. Screening may actually increase satisfaction with care. In addition, families who do not show up for appointments are at higher risk. Therefore, screening only at well visits will miss an important group. CONCLUSIONS: Maternal domestic violence screening at well-child visits is practical in a private pediatric office setting. Current rates of screening are low; however, most mothers favor such screening. Furthermore, MDV screening should also be offered on a catch-up basis for those who miss well-child visits, as is currently recommended for immunizations.

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1. Production-induced osteoporosis in caged laying hens is thought to represent a major constraint to continued genetic development. 2. The relationship between body weight, egg production, skeletal abnormalities characteristic of osteoporosis, femur calcium and bone histology was examined in a flock of ISA Brown layers from 16 to 68 weeks of age. 3. Experiment 2 examined a flock of Lohmann browns for skeletal abnormalities characteristic of osteoporosis at 45 weeks of age and the severity of abnormalities was then related to body weight and production between 18 and 45 weeks of age. 4. Average body weight declined in the ISA flock between 35 and 45 weeks of age, which correlated with a loss of skeletal calcium reserves (15% to 20%) and with the induction of osteoporosis. Between 42 and 68 weeks of age, birds were able to replenish femur calcium levels. 5. Birds in the Lohmann flock showing severe skeletal abnormalities at 45 weeks of age experienced weight loss between 27 and 31 weeks of age, which was associated with a decrease in egg production of 18%. After 35 weeks of age, egg production of these birds recovered to similar levels as unaffected or mildly affected birds. 6. It seems likely that better standardisation of the equilibrium between growth, skeletal reserves, food intake and egg production can reduce osteoporosis, as well as improving the productive potential of modern laying strains.

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The synthesis and evaluation of the novel head-to-head bisbenzimidazole compound 2,2-bis[4'-(3' '-dimethylamino-1' '-propyloxy)phenyl]-5,5-bi-1H-benzimidazole is described. An X-ray crystallographic study of a complex with the DNA dodecanucleotide sequence d(CGCGAATTCGCG) shows the compound bound in the A/T minor groove region of a B-DNA duplex and that the head-to-head bisbenzimidazole motif hydrogen-bonds to the edges of all four consecutive A:T base pairs. The compound showed potent growth inhibition with a mean IC(50) across an ovarian carcinoma cell line panel of 0.31 microM, with no significant cross-resistance in two acquired cisplatin-resistant cell lines and a low level of cross-resistance in the P-glycoprotein overexpressing acquired doxorubicin-resistant cell line. Studies with the hollow fiber assay and in vivo tumor xenografts showed some evidence of antitumor activity.

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The FMN-dependent flavoprotein nitroreductase from Escherichia coli B (NTR) is used in cancer chemotherapy to activate a range of prodrugs. The crystal structure of this enzyme has been determined, using molecular replacement methods and refined at 2.06 A resolution. The recombinant 24-kDa enzyme was crystallized in the tetragonal space group P4(1)2(1)2, with unit cell dimensions of a = b = 57.74 A and c = 275.51 A and two molecules in the asymmetric unit. The structure has a final R factor of 20.3% (R(free) = 26.7%), for all data between the resolution ranges of 10-2.06 A, and includes 4453 protein atoms, 230 water molecules, and 2 flavin mononucleotide (FMN) molecules. The functional unit is a homodimer, which forms the asymmetric unit in the crystal structure. The tertiary structures of these two monomers and their subunit interactions are nearly identical. The molecular replacement search model, the crystal structure of the major NAD(P)H:FMN oxidoreductase of Vibrio fisheri (FRase 1), was selected on the basis of its high sequence identity to that of NTR. The final superposition of these two enzymes revealed a very similar overall fold, with variation in the structures focused around surface loops and helices near the FMN cofactor. Helix G is implicated in substrate specificity and is better resolved in the present NTR structure than in the previously reported FRase 1 structure. The FMN binding pocket is also well-resolved, showing the presence of two channels leading into the active site. The amino acid side chains and main chain atoms interacting with the FMN are well-ordered. The structure of the substrate binding pocket has been used to examine substrate specificity and enzyme kinetics for prodrugs used in antibody-directed enzyme prodrug therapy (ADEPT) and gene-directed enzyme prodrug therapy (GDEPT).

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The dodecanucleotide d(CGCGAATTCGCG) has been crystallised in the space group P3(2)12, representing a new crystal form for this sequence. The structure has been solved by molecular replacement and refined at 1.8 A resolution. The present structure contrasts with previous ones for this sequence since it is situated on a crystallographic 2-fold axis, and the crystal symmetry reflects the palindromic nature of this sequence. Some features accord with previous observations, notably that the minor groove is hydrated with a continuous spine of solvent. There is no evidence of alkali metal ions within this spine. The minor groove retains its narrow width, although it is now symmetric and extends over the A/T tract. Various base and base-pair morphological parameters have been examined. Their values do not show significant correlations with earlier reports, suggesting that crystal packing effects on them are more dominant than has been hitherto realised.

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This study assessed anxiety levels of parents of young febrile children who presented to a pediatric emergency department (ED) with fever. One hundred and seventy parents completed a 90-item questionnaire. Anxiety was measured by use of the State Trait Anxiety Inventory. Parents were asked what they had previously thought about and how they felt about the ED process. Mean parental anxiety was 50.1 (95% CI 48.1, 52.2), significantly elevated from adult standards (p < 0.0001). A multivariate model comprising: (1) feeling "not at all" well rested, (2) having no other children, (3) having thought about a blood test, and (4) feeling worried about trusting the physician was associated with elevated anxiety. In conclusion, parents of febrile young children in the ED are very anxious.

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Recent advances in understanding the molecular level mechanisms that control biomineralization and organic-inorganic interactions in urolithiasis are reviewed, and the validity of drawing parallels between them are considered. The multifunctional nature of many biomineralization molecules, particularly proteins, and the different roles they play in and out of solution suggest avenues for resolving the apparent paradox that urinary macromolecules have been observed both to inhibit and to promote stone formation.

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OBJECTIVE: To investigate potential mechanisms by which CD40L-mediated signals may be involved in the pathogenesis of lupus glomerulonephritis (GN). METHODS: Renal in situ CD40L and CD40 expression was examined in patient biopsy specimens. Immunohistochemical studies were performed on frozen sections utilizing anti-CD40L monoclonal antibody (MAb), anti-CD40 MAb, or control MAb. As controls, we analyzed normal kidney specimens and specimens obtained from patients with IgA nephropathy, focal segmental glomerulosclerosis, minimal change disease, idiopathic membranous GN, and antineutrophil cytoplasmic antibody-positive pauci-immune GN. Staining distribution was noted and staining intensity scored on a semiquantitative scale of 0 (no staining) to 3+ (intense staining). RESULTS: In normal kidney, CD40 was expressed on parietal epithelial cells, mesangial cells, endothelial cells, and distal tubules but not proximal tubules. Glomerular and tubular CD40 expression was markedly up-regulated in class III and class IV lupus GN, where there was intense staining of crescents, proximal and distal tubules, and interstitial mononuclear cells. In contrast, CD40 expression in class V lupus GN was similar to that in normal kidney. Interstitial mononuclear cells expressing CD40L were present in class IV lupus GN. However, these findings were not unique to lupus GN: up-regulation of CD40 and CD40L expression was similarly observed in other inflammatory renal diseases. CONCLUSION: This study shows that CD40 is expressed on a variety of renal parenchymal and non-parenchymal cells in normal kidney. Renal CD40 expression is up-regulated in class III and class IV lupus nephritis, as well as in other inflammatory renal diseases, and is associated with the presence of CD40L+ mononuclear cells.

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The crystallographic structure of the CAP-DNA complex at 3.0 A resolution has been reported previously. For technical reasons, the reported structure had been determined using a gapped DNA molecule lacking two phosphates important for CAP-DNA interaction. In this work, we report the crystallographic structure of the CAP-DNA complex at 2.5 A resolution using a DNA molecule having all phosphates important for CAP-DNA interaction. The present resolution permits unambiguous identification of amino acid-base and amino acid-phosphate hydrogen bonded contacts in the CAP-DNA complex. In addition, the present resolution permits accurate definition of the kinked DNA conformation in the CAP-DNA complex.

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Two commercial broiler flocks of two distinct strains (A and B) were studied at weekly intervals from day old to 21 days, to assess the progressive endochondral ossification of the proximal tibiotarsus and the serum concentration of 1,25-dihydroxycholecalciferol (1,25(OH)2D3). The incidence of defects of endochondral ossification was different in the two strains, strain B having an incidence of tibial dyschondroplasia (TD) of 10 to 70 per cent and strain A an incidence of 10 to 20 per cent. In strain B, 40 per cent of the bone samples collected at 14 days of age also had lesions of calcium deficiency rickets. The concentration of 1,25(OH)2D3 in the two flocks was similar in the day-old chicks, but was 40 to 50 per cent lower at seven, 14 and 21 days of age in strain B, during the development of the rachitic and dyschondroplastic lesions. These results suggest that TD in some broiler strains is related to an inherent predisposition to rickets and to lower serum concentrations of 1,25(OH)2D3.

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