Atom probe tomography analysis of SiGe fins embedded in SiO2: Facts and artefacts.

We present atom probe analysis of 40nm wide SiGe fins embedded in SiO2 and discuss the root cause of artefacts observed in the reconstructed data. Additionally, we propose a simple data treatment routine, relying on complementary transmission electron microscopy analysis, to improve compositional analysis of the embedded SiGe fins. Using field evaporation simulations, we show that for high oxide to fin width ratios the difference in evaporation field thresholds between SiGe and SiO2 results in a non-hemispherical emitter shape with a negative curvature in the direction across, but not along the fin. This peculiar emitter shape leads to severe local variations in radius and hence in magnification across the emitter apex causing ion trajectory aberrations and crossings. As shown by our experiments and simulations, this translates into unrealistic variations in the detected atom densities and faulty dimensions in the reconstructed volume, with the width of the fin being up to six-fold compressed. Rectification of the faulty dimensions and density variations in the SiGe fin was demonstrated with our dedicated data treatment routine.

Auscultate, palpate and tap: time to re-evaluate.

AIM: To determine the accuracy of current methods of heart rate (HR) assessment. METHODS: All participants palpated a simulated pulsating umbilicus (UMB), listened to a tapping rate (TAP) and auscultated a simulated HR (AUSC). A simulated HR of 54, 88 and 128 beats per minute (bpm) was randomised for all methods. RESULTS: Twenty-nine healthcare staff participated in this study. Correct assessment of HR of 54 bpm as being within the 0-59 range occurred in 17.2% UMB, 17.2% TAP and 31% AUSC and was obtained in <10 seconds by 48.3%, 65.5% and 62.1%, respectively. A rate of 88 bpm was correctly assessed as within the 60-100 range in 82.8% UMB, 79.3% TAP and 79.3% AUSC and was obtained in <10 seconds by 55.2%, 58.6% and 55.2%, respectively. A rate of 128 bpm was identified as >100 bpm by 96.6% UMB, 93.1% TAP, and 93.1% AUSC and was obtained in <10 seconds by 51.7%, 55.2% and 62.1%, respectively. CONCLUSION: Current methods in assessing rates below 60 bpm are inaccurate and may overestimate HR. We recommend that these methods alone should not be relied upon in neonatal resuscitation and objective assessment of heart rate should be readily available at all newborn resuscitations.

Impairing MLL-fusion gene-mediated transformation by dissecting critical interactions with the lens epithelium-derived growth factor (LEDGF/p75).

The lens epithelium-derived growth factor (LEDGF/p75) tethers the mixed-lineage leukemia (MLL1) protein complex to chromatin. Likewise, LEDGF/p75 tethers the HIV-1 pre-integration complex to chromatin. We previously demonstrated that expression of the C-terminal fragment fused to enhanced green fluorescent protein (eGFP) (eGFP-LEDGF(325-530)) impaired HIV-1 replication. Here, we explored this strategy to selectively interfere with the leukemogenic activity of MLL-fusion proteins. We found that expression of LEDGF(325-530) impaired the clonogenic growth of MLL-fusion gene transformed human and mouse hematopoietic cells, without affecting the growth of control cells immortalized by the FLT3-ITD mutant or normal lineage-marker-depleted murine bone marrow cells. Expression of LEDGF(325-530) was associated with downregulation of the MLL target Hoxa9 and impaired cell cycle progression. Structure-function analysis revealed two small eGFP-fused LEDGF/p75 peptides, LEDGF(424-435) and LEDGF(375-386) phenocopying these effects. Both LEDGF(325-530) and the smaller active peptides were able to disrupt the LEDGF/p75-MLL interaction. Expression of LEDGF(325-530) or LEDGF(375-386) fragments increased the latency period to disease development in vivo in a mouse bone marrow transplant model of MLL-AF9-induced AML. We conclude that small peptides disrupting the LEDGF/p75-MLL interface have selective anti-leukemic activity providing a direct rationale for the design of small molecule inhibitors targeting this interaction.

Paramagnetism and antiferromagnetic interactions in Cr-doped GaN.

We report on the magnetic and structural properties of Cr-doped GaN prepared by ion implantation of epitaxial thin films. Based on a detailed analysis of the magnetometry data, we demonstrate that the magnetic interactions between Cr moments in GaN are antiferromagnetic (AFM). Increasing the Cr fractional concentration up to 0.35, we observe that strong nearest cation neighbor AFM coupling results in the reduction of the effective moment per Cr atom. The uncompensated Cr moments exhibit paramagnetic behavior and we discuss to what extent the effects of an anisotropic crystal field and AFM interactions can be inferred from the magnetization data. We discuss the observed changes in magnetic and structural properties induced by thermal annealing in terms of defect annealing and Cr aggregation.

Artificial neural networks applied to the analysis of synchrotron nuclear resonant scattering data.

The capabilities of artificial neural networks (ANNs) have been investigated for the analysis of nuclear resonant scattering (NRS) data obtained at a synchrotron source. The major advantage of ANNs over conventional analysis methods is that, after an initial training phase, the analysis is fully automatic and practically instantaneous, which allows for a direct intervention of the experimentalist on-site. This is particularly interesting for NRS experiments, where large amounts of data are obtained in very short time intervals and where the conventional analysis method may become quite time-consuming and complicated. To test the capability of ANNs for the automation of the NRS data analysis, a neural network was trained and applied to the specific case of an Fe/Cr multilayer. It was shown how the hyperfine field parameters of the system could be extracted from the experimental NRS spectra. The reliability and accuracy of the ANN was verified by comparing the output of the network with the results obtained by conventional data analysis.

Polymerase chain reaction analysis of the surgical margins of equine sarcoids for bovine papilloma virus DNA.

OBJECTIVE: To examine apparently normal skin around equine sarcoids for evidence of bovine papilloma virus (BPV) DNA, and to relate this finding to the observed recurrence after surgery. STUDY DESIGN: Prospective study. ANIMALS OR SAMPLE POPULATION: Forty-one equine sarcoids from 19 horses. MATERIALS AND METHODS: The tumors were surgically excised at a measured distance of 8, 12, or 16 mm. Samples from the tumor and of the entire surrounding skin were taken at 4, 8, 12, and 16 mm from the tumor border and analyzed for the presence of BPV DNA using polymerase chain reaction (PCR) amplification. The samples were grouped per examined sarcoid, and a tumor was considered positive at a certain distance as soon as at least one of the samples at that distance was positive. The clinical outcome was recorded for each sarcoid after a minimal follow-up of 6 months. RESULTS: All sarcoids were positive for BPV(1) or BPV(2). The tumor margin was positive at 4, 8, 12, and 16 mm in, respectively, 95%, 73%, 39%, and 33% of the examined sarcoids. Local recurrence was observed in 3 sarcoids on 3 different horses. From survival analysis, there was a greater likelihood for local recurrence when sarcoids had a surgical margin that was positive for BPV DNA. CONCLUSIONS AND CLINICAL RELEVANCE: BPV DNA is often detected in visibly normal skin around sarcoids, and there is a significantly greater probability for local recurrence when the surgical margins are positive for the presence of BPV DNA.

Histopathological characteristics of five clinical types of equine sarcoid.

The purpose of this study was to determine the characteristics of occult, verrucous, fibroblastic, nodular and mixed equine sarcoids. Ten tumours of each type were examined histologically and analysed for the presence of bovine papilloma virus (BPV)- DNA. All tumours were positive for BPV - DNA and showed an increased density of dermal fibroblasts. Epidermal hyperplasia, hyperkeratosis, rete peg and 'picket fence' formation were only found consistently in the verrucous and mixed types and were often not present in occult and nodular sarcoids. Immunohistochemical staining for Keratins 10 and 16, Ki67 and p53 showed no important differences between the clinical types. It can be concluded that the presence of BPV - DNA and the increased density of dermal fibroblasts were the only common characteristics for all sarcoids of the different clinical types. The presence of other microscopic alterations was variable but could not be used in the differentiation of the clinical types based on histology.

Clinical examination of the T.M.J. interobserver reliability.

A clinical study was performed on 18 healthy persons, chosen at random and without major T.M.J. complaints, by 4 different examiners (2 physiotherapists and 2 oral and maxillo-facial surgeons). The main goal was to examine the interobserver reliability of the different clinical examination methods commonly used in the department of Oral and Maxillo-Facial surgery and physiotherapy. The clinical examination consisted of bilateral palpation of the active movements of the T.M.J., evaluation of the passive movements and evaluation by specific manual distraction and compression tests. Statistical processing was performed with a Pearson correlation coefficient. The critical positive value for a good correlation was never reached. Although evaluation of 5 subjects with minor complaints, shows a low tendency of positive correlation. Therefore, interobserver reliability for the examination of the T.M.J. seems to be fictive in an at random sample. Examination of pathologic cases may be more concordant.

Periodontal infection leading to periostitis ossificans ("Garrè's osteomyelitis") of the mandible. Report of a case.

Periostitis ossifications ("Garrè's osteomyelitis") of the mandible is a rather rare pathology that occurs as a hard swelling at the mandibular angle, persists for a long period, and is mostly painful on palpation. Clinical signs of infection are rarely noted. The etiological factor is generally a carious first permanent molar with a periapical infection or a fracture of the jaw. In this case, a 10 year-old girl showed a fixed painful swelling of the right mandibular angle. This revealed to be periostitis ossificans, although none of the classical causes were present. The symptoms were evoked by a periodontal infection: there was an osseous crater and a probing pocket depth of more than 10 mm disto-lingually of the first right permanent molar of the mandible. This was likely the etiological factor. Extraction of the first and second permanent right molar, curettage of the corresponding alveoli, and antibiotic treatment resulted in complete healing, clinically and radiologically, after 9 months.