197 research outputs found
Single atoms in a standing-wave dipole trap
We trap a single cesium atom in a standing-wave optical dipole trap. Special
experimental procedures, designed to work with single atoms, are used to
measure the oscillation frequency and the atomic energy distribution in the
dipole trap. These methods rely on unambiguously detecting presence or loss of
the atom using its resonance fluorescence in the magneto-optical trap.Comment: 8 pages, 7 figures, submitted to Phys. Rev.
An optical conveyor belt for single neutral atoms
Using optical dipole forces we have realized controlled transport of a single
or any desired small number of neutral atoms over a distance of a centimeter
with sub-micrometer precision. A standing wave dipole trap is loaded with a
prescribed number of cesium atoms from a magneto-optical trap. Mutual detuning
of the counter-propagating laser beams moves the interference pattern, allowing
us to accelerate and stop the atoms at preselected points along the standing
wave. The transportation efficiency is close to 100%. This optical "single-atom
conveyor belt" represents a versatile tool for future experiments requiring
deterministic delivery of a prescribed number of atoms on demand.Comment: 8 pages, 8 figures, submitted to Applied Physics
Großflächige Abscheidung von Graphen - Ein wichtiger Schritt für neuartige Bauelemente
Das wachsende Interesse an Graphen beruht auf seiner unverwechselbaren Bandstruktur und seinen damit zusammenhängenden herausragenden physikalischen Eigenschaften. Es wird daher weltweit nach einem Verfahren gesucht, Graphen großflächig und mit hoher Qualität abzuscheiden. In einer an der TH Wildau [FH] speziell für diese Aufgabe konzipierten Reaktionskammer wurde die Herstellung mittels chemischer Gasphasenabscheidung auf katalytischen Metalloberflächen für verschiedene Parameter studiert und deren Verträglichkeit mit der CMOS -Technologie untersucht. Die ersten Tests erfolgten auf Nickel, da hier eine im Volumen stattfindende katalytische Reaktion einsetzt. In weiteren Schritten fiel die Wahl auf Kupfer, da hier die Reaktion an der Oberfläche stattfindet und daher ein stabilerer Prozess realisiert werden konnte. Die Qualitätsprüfung der erzeugten Schichten erfolgte mittels Ramanspektrometrie
Verordnungsentwurf der EU-Kommission zur künftigen Förderung der Entwicklung des ländlichen Raums: Vergleich zur derzeitigen Ausgestaltung der Förderpolitik und Kommentierung der Änderungen
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Analyzing quantum jumps of one and two atoms strongly coupled to an optical cavity
We induce quantum jumps between the hyperfine ground states of one and two
Cesium atoms, strongly coupled to the mode of a high-finesse optical resonator,
and analyze the resulting random telegraph signals. We identify experimental
parameters to deduce the atomic spin state nondestructively from the stream of
photons transmitted through the cavity, achieving a compromise between a good
signal-to-noise ratio and minimal measurement-induced perturbations. In order
to extract optimum information about the spin dynamics from the photon count
signal, a Bayesian update formalism is employed, which yields time-dependent
probabilities for the atoms to be in either hyperfine state. We discuss the
effect of super-Poissonian photon number distributions caused by atomic motion.Comment: 12 pages, 13 figure
A Review of the Role of Causality in Developing Trustworthy AI Systems
State-of-the-art AI models largely lack an understanding of the cause-effect
relationship that governs human understanding of the real world. Consequently,
these models do not generalize to unseen data, often produce unfair results,
and are difficult to interpret. This has led to efforts to improve the
trustworthiness aspects of AI models. Recently, causal modeling and inference
methods have emerged as powerful tools. This review aims to provide the reader
with an overview of causal methods that have been developed to improve the
trustworthiness of AI models. We hope that our contribution will motivate
future research on causality-based solutions for trustworthy AI.Comment: 55 pages, 8 figures. Under revie
Liver resection or combined chemoembolization and radiofrequency ablation improve survival in patients with hepatocellular carcinoma
Background/ Aims: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). Methods: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM- HCC). Results: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection ( n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation ( RFA) ( n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p <= 0.004) improved survival time in VISUM stage 1 - 2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. Conclusion: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC
High-Performance Thin-Layer Chromatography-Immunostaining as a Technique for the Characterization of Whey Protein Enrichment in Edam Cheese
Whey protein-enriched cheese can be produced by means of a high-temperature treatment of a part of the cheese milk. In this way, the nutritional quality of the resulting cheeses can be increased while resources are conserved. High-performance thin-layer chromatography-immunostaining (HPTLC-IS) using specific β-lactoglobulin (β-LG) antibodies was applied to study the implementation and stability of β-LG in two different sample sets of whey protein-enriched Edam model cheeses, including industrial-scale ones. Two methods were compared for the extraction of the proteins/peptides from the cheese samples. By applying tryptic hydrolysis directly from a suspended cheese sample instead of a supernatant of a centrifuged suspension, a better yield was obtained for the extraction of β-LG. When applying this method, it was found that selected epitopes in the tryptic β-LG peptides remain stable over the ripening period of the cheese. For four of the tryptic β-LG peptides detected by immunostaining, the amino acid sequence was identified using MALDI-TOF-MS/MS. One of the peptides identified was the semi-tryptic peptide VYVEELKPTP. A linear relationship was found between the content of this peptide in cheese and the proportion of high-heated milk in the cheese milk. β-LG enrichment factors of 1.72 (n = 3, sample set I) and 1.33 ± 0.19 (n = 1, sample set II) were determined for the cheese samples containing 30% high-heated milk compared to the non-enriched samples. The relative β-LG contents in the cheese samples with 30% high-heated milk were calculated to be 4.35% ± 0.39% (sample set I) and 9.11% ± 0.29% (sample set II) using a one-point calibration. It can be concluded that the HPTLC-IS method used is a suitable tool for the analysis of whey protein accumulation in cheese, being therefore potentially directly applicable on an industrial scale. For more accurate quantification of the whey protein content in cheese, an enhanced calibration curve needs to be applied.BMEL, 281A107916, Verbundprojekt: Entwicklung innovativer Analysenverfahren zum Nachweis von Molkenproteinen und Etablierung von Biomarkern als Qualitätsparameter bei Molkenprotein-angereichertem Schnittkäse (Molkkaese) - Teilprojekt
The influence of obesity on survival in early, high-risk breast cancer: results from the randomized SUCCESS A trial
Introduction: Obese breast cancer patients have worse prognosis than normal weight patients, but the level at which obesity is prognostically unfavorable is unclear. Methods: This retrospective analysis was performed using data from the SUCCESS A trial, in which 3754 patients with high-risk early breast cancer were randomized to anthracycline- and taxane-based chemotherapy with or without gemcitabine. Patients were classified as underweight/normal weight (body mass index (BMI) < 25.0), overweight (BMI 25.0–29.9), slightly obese (BMI 30.0–34.9), moderately obese (BMI 35.0–39.9) and severely obese (BMI ≥ 40.0), and the effect of BMI on disease-free survival (DFS) and overall survival (OS) was evaluated (median follow-up 65 months). In addition, subgroup analyses were conducted to assess the effect of BMI in luminal A-like, luminal B-like, HER2 (human epidermal growth factor 2)-positive and triple-negative tumors. Results: Multivariate analyses revealed an independent prognostic effect of BMI on DFS (p = 0.001) and OS (p = 0.005). Compared with underweight/normal weight patients, severely obese patients had worse DFS (hazard ratio (HR) 2.70, 95 % confidence interval (CI) 1.71–4.28, p < 0.001) and OS (HR 2.79, 95 % CI 1.63–4.77, p < 0.001), while moderately obese, slightly obese and overweight patients did not differ from underweight/normal weight patients with regard to DFS or OS. Subgroup analyses showed a similar significant effect of BMI on DFS and OS in patients with triple-negative breast cancer (TNBC), but not in patients with other tumor subtypes. Conclusions: Severe obesity (BMI ≥ 40) significantly worsens prognosis in early breast cancer patients, particularly for triple-negative tumors. Trial registration: Clinicaltrials.gov NCT02181101. Registered September 200
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