Al-alkyls as acceptor dopant precursors for atomic-scale devices.

Atomically precise ultradoping of silicon is possible with atomic resists, area-selective surface chemistry, and a limited set of hydride and halide precursor molecules, in a process known as atomic precision advanced manufacturing (APAM). It is desirable to expand this set of precursors to include dopants with organic functional groups and here we consider aluminium alkyls, to expand the applicability of APAM. We explore the impurity content and selectivity that results from using trimethyl aluminium and triethyl aluminium precursors on Si(001) to ultradope with aluminium through a hydrogen mask. Comparison of the methylated and ethylated precursors helps us understand the impact of hydrocarbon ligand selection on incorporation surface chemistry. Combining scanning tunneling microscopy and density functional theory calculations, we assess the limitations of both classes of precursor and extract general principles relevant to each.

Glucocorticoid receptor number and affinity differ between peripheral blood mononuclear cells and granulocytes in domestic pigs.

The aim of the present study was to characterize the number and affinity of glucocorticoid receptors (GR) in peripheral blood mononuclear cells (PBMC) and granulocytes of domestic pigs because glucocorticoid signaling is considered important for animal health and welfare. To investigate GR binding characteristics in intact porcine immune cells, blood samples of 6 castrated male pigs were collected via indwelling vein catheters. Porcine PBMC and granulocytes were isolated using two-layer density gradients, followed by radioligand binding assays to determine the number of GR sites per cell and the dissociation constant Kd as a measure for GR binding affinity. The present study revealed a greater number of GR sites per cell (P = 0.039) in PBMC (mean ± SEM: 1,953 ± 207 sites/cell) compared to granulocytes (1,561 ± 159 sites/cell) in domestic pigs. Furthermore, porcine PBMC had a higher GR binding affinity than porcine granulocytes (P = 0.003) as the dissociation constant Kd of PBMC (1.8 ± 0.2 nM) was lower than that of granulocytes (3.5 ± 0.4 nM). Our results point to differences in underlying mechanisms of glucocorticoid signaling in different porcine leukocyte populations.

Characterization of the adaptive immune response following immunization in pregnant sows (Sus scrofa) kept in two different housing systems.

Housing conditions might differentially affect the adaptive immune responses to a neoantigen in pregnant sows with possible consequences for the success of vaccinations. Therefore, this study aimed at characterizing antigen-specific T cell and B cell responses of pregnant sows (German Landrace) either housed in a social group (GP; n = 22) or confined in individual gestation crates (CR; n = 11). All sows were immunized with the neoantigen keyhole limpet hemocyanin (KLH) 7 and 5 wk prepartum. Blood samples were taken 7, 6, 4, and 2 wk prepartum, thus before and after the first as well as second immunization. This study aimed at identifying both the resulting cellular as well as humoral KLH-specific immune response in the pregnant sows. We therefore analyzed total IgG and anti-KLH IgG concentrations and the KLH-specific lymphocyte proliferation as well as the KLH-specific production of the T helper cell type 1 (TH1)-related cytokines tumor necrosis factor (TNF) α and interferon (IFN) γ in main T cell subsets before and after the immunization. Anti-KLH IgG titers significantly increased during the experimental procedure (P < 0.001) reflecting the activation and differentiation of KLH-specific B cells on immunization. However, CR-housed sows showed greater anti-KLH IgG concentrations compared to GP-housed sows (P < 0.05). Keyhole limpet hemocyanin-specific TNFα-producing cytotoxic T cells (CTL) and T helper (TH) cells were detectable in CR-housed sows not before the second immunization (both P < 0.05), whereas those cells were detectable already after the first immunization in GP-housed sows (CTL: P < 0.01 and TH: P < 0.05). Similarly, KLH-specific TNFα/IFNγ-double producing CTL and TH cells were detectable earlier in GP-housed sows than in CR-housed sows (both P < 0.05). Keyhole limpet hemocyanin-induced lymphocyte proliferation and total IgG concentrations were not affected by the housing system. Our results show that housing conditions affect the adaptive immunity to a neoantigen in pregnant sows. Whereas GP housing of pregnant sows induced a rather TH1-mediated cellular response, individual housing in CR resulted in a T helper cell type 2 (TH2)-pronounced humoral response to KLH. The greater anti-KLH IgG concentration and the delayed activation and differentiation of KLH-specific TH1 cells in CR-housed sows support the hypothesis of a shifted TH1:TH2 ratio in individually housed sows of this study. We presume differences in the stressfulness of the housing system to be mainly responsible for the occurring effects.

Field-directed sputter sharpening for tailored probe materials and atomic-scale lithography.

Fabrication of ultrasharp probes is of interest for many applications, including scanning probe microscopy and electron-stimulated patterning of surfaces. These techniques require reproducible ultrasharp metallic tips, yet the efficient and reproducible fabrication of these consumable items has remained an elusive goal. Here we describe a novel biased-probe field-directed sputter sharpening technique applicable to conductive materials, which produces nanometer and sub-nanometer sharp W, Pt-Ir and W-HfB(2) tips able to perform atomic-scale lithography on Si. Compared with traditional probes fabricated by etching or conventional sputter erosion, field-directed sputter sharpened probes have smaller radii and produce lithographic patterns 18-26% sharper with atomic-scale lithographic fidelity.

Reduction in growth threshold for pulmonary metastases: an opportunity for volumetry and its impact on treatment decisions.

OBJECTIVES: This study compares tumour response assessment by automated CT volumetry and standard manual measurements regarding the impact on treatment decisions and patient outcome. METHODS: 58 consecutive patients with 203 pulmonary metastases undergoing baseline and follow-up multirow detector CT (MDCT) under chemotherapy were assessed for response to chemotherapy. Tumour burden of pulmonary target lesions was quantified in three ways: (1) following response evaluation criteria in solid tumours (RECIST); (2) following the volume equivalents of RECIST (i.e. with a threshold of -65/+73%); and (3) using calculated limits for stable disease (SD). For volumetry, calculated limits had been set at ±38% prior to the study by repeated quantification of nodules scanned twice. Results were compared using non-weighted κ-values and were evaluated for their impact on treatment decisions and patient outcome. RESULTS: In 15 (17%) of the 58 patients, the results of response assessment were inconsistent with 1 of the 3 methods, which would have had an impact on treatment decisions in 8 (13%). Patient outcome regarding therapy response could be verified in 5 (33%) of the 15 patients with inconsistent measurement results and was consistent with both RECIST and volumetry in 1, with calculated limits in 3 and with none in 1. Diagnosis as to the overall response was consistent with RECIST in six patients, with volumetry in six and with calculated limits in eight cases. There is an impact of different methods for therapy response assessment on treatment decisions. CONCLUSION: A reduction of threshold for SD to ±30-40% of volume change seems reasonable when using volumetry.

Inducing electronic changes in graphene through silicon (100) substrate modification.

We have performed scanning tunneling microscopy and spectroscopy (STM/STS) measurements as well as ab initio calculations for graphene monolayers on clean and hydrogen(H)-passivated silicon (100) (Si(100)/H) surfaces. In order to experimentally study the same graphene piece on both substrates, we develop a method to depassivate hydrogen from under graphene monolayers on the Si(100)/H surface. Our work represents the first demonstration of successful and reproducible depassivation of hydrogen from beneath monolayer graphene flakes on Si(100)/H by electron-stimulated desorption. Ab initio simulations combined with STS taken before and after hydrogen desorption demonstrate that graphene interacts differently with the clean and H-passivated Si(100) surfaces. The Si(100)/H surface does not perturb the electronic properties of graphene, whereas the interaction between the clean Si(100) surface and graphene changes the electronic states of graphene significantly. This effect results from the covalent bonding between C and surface Si atoms, modifying the π-orbital network of the graphene layer. The local density of states shows that the bonded C and Si surface states are highly disturbed near the Fermi energy.

[Automated pulmonary nodule volumetry with an optimized algorithm. Accuracy at different slice thicknesses compared to unidimensional and bidimensional measurements]. / Lungenrundherdvolumetrie mit optimiertem Segmentierungsalgorithmus. Genauigkeit bei verschiedenen Schichtdicken verglichen mit ein- und zweidimensionalen Messungen.

PURPOSE: This in-vivo study quantifies the accuracy of automated pulmonary nodule volumetry in reconstructions with different slice thicknesses (ST) of clinical routine CT scans. The accuracy of volumetry is compared to that of unidimensional and bidimensional measurements. MATERIALS AND METHODS: 28 patients underwent contrast enhanced 64-row CT scans of the chest and abdomen obtained in the clinical routine. All scans were reconstructed with 1, 3, and 5 mm ST. Volume, maximum axial diameter, and areas following the guidelines of Response Evaluation Criteria in Solid Tumors (RECIST) and the World Health Organization (WHO) were measured in all 101 lesions located in the overlap region of both scans using the new software tool OncoTreat (MeVis, Deutschland). The accuracy of quantifications in both scans was evaluated using the Bland and Altmann method. The reproducibility of measurements in dependence on the ST was compared using the likelihood ratio Chi-squared test. RESULTS: A total of 101 nodules were identified in all patients. Segmentation was considered successful in 88.1% of the cases without local manual correction which was deliberately not employed in this study. For 80 nodules all 6 measurements were successful. These were statistically evaluated. The volumes were in the range 0.1 to 15.6 ml. Of all 80 lesions, 34 (42%) had direct contact to the pleura parietalis oder diaphragmalis and were termed parapleural, 32 (40%) were paravascular, 7 (9%) both parapleural and paravascular, the remaining 21 (27%) were free standing in the lung. The trueness differed significantly (Chi-square 7.22, p value 0.027) and was best with an ST of 3 mm and worst at 5 mm. Differences in precision were not significant (Chi-square 5.20, p value 0.074). The limits of agreement for an ST of 3 mm were +/- 17.5 % of the mean volume for volumetry, for maximum diameters +/- 1.3 mm, and +/- 31.8 % for the calculated areas. CONCLUSION: Automated volumetry of pulmonary nodules using OncoTREAT has a conformable accuracy for an ST of 3 mm and 1 mm and is even more accurate for an ST of 5 mm than unidimensional or bidimensional measurements. A difference of more than +/- 17.5% occurs with a probability of less than 5% at an ST of 3 mm.

Improving continuity of care by evaluation of post-discharge outcomes.

Evaluation of nursing care is being expanded to identify and assure attainment of patient outcomes. Ideally, evaluation of care will occur throughout all phases of treatment and include perceptions of the patient and/or significant others. A framework for patient outcomes as proposed by Marek (1989) was useful in defining outcomes for newly injured and chronically skin-compromised patients with spinal cord injury. Guidelines established by the Joint Commission for Accreditation of Health Organizations also influenced development of the nursing quality assurance approach. A pilot program demonstrated attainment of expected patient outcomes for high-risk and problem-prone aspects of nursing care.