Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
Add more filters










Publication year range
1.
Eur Phys J A Hadron Nucl ; 57(4): 152, 2021.
Article in English | MEDLINE | ID: mdl-34776778

ABSTRACT

Psychological bias towards, or away from, prior measurements or theory predictions is an intrinsic threat to any data analysis. While various methods can be used to try to avoid such a bias, e.g. actively avoiding looking at the result, only data blinding is a traceable and trustworthy method that can circumvent the bias and convince a public audience that there is not even an accidental psychological bias. Data blinding is nowadays a standard practice in particle physics, but it is particularly difficult for experiments searching for the neutron electric dipole moment (nEDM), as several cross measurements, in particular of the magnetic field, create a self-consistent network into which it is hard to inject a false signal. We present an algorithm that modifies the data without influencing the experiment. Results of an automated analysis of the data are used to change the recorded spin state of a few neutrons within each measurement cycle. The flexible algorithm may be applied twice (or more) to the data, thus providing the option of sequentially applying various blinding offsets for separate analysis steps with independent teams. The subtle manner in which the data are modified allows one subsequently to adjust the algorithm and to produce a re-blinded data set without revealing the initial blinding offset. The method was designed for the 2015/2016 measurement campaign of the nEDM experiment at the Paul Scherrer Institute. However, it can be re-used with minor modification for the follow-up experiment n2EDM, and may be suitable for comparable projects elsewhere.

2.
Phys Rev Lett ; 124(8): 081803, 2020 Feb 28.
Article in English | MEDLINE | ID: mdl-32167372

ABSTRACT

We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a ^{199}Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{n}=(0.0±1.1_{stat}±0.2_{sys})×10^{-26} e.cm.

3.
Nano Lett ; 17(12): 7647-7651, 2017 12 13.
Article in English | MEDLINE | ID: mdl-29136385

ABSTRACT

The performance gain-oriented nanostructurization has opened a new pathway for tuning mechanical features of solid matter vital for application and maintained performance. Simultaneously, the mechanical evaluation has been pushed down to dimensions way below 1 µm. To date, the most standard technique to study the mechanical properties of suspended 2D materials is based on nanoindentation experiments. In this work, by means of micro-Brillouin light scattering we determine the mechanical properties, that is, Young modulus and residual stress, of polycrystalline few nanometers thick MoS2 membranes in a simple, contact-less, nondestructive manner. The results show huge elastic softening compared to bulk MoS2, which is correlated with the sample morphology and the residual stress.

4.
Poult Sci ; 96(9): 3338-3350, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28854758

ABSTRACT

Four experiments were carried out to study the possible differences in metabolizable energy (ME) of meals (RSM) or expeller meals (RSE) from double-low rapeseed (Expt. 1), the influence of processing on ME (Expt. 2) and on relative phosphorus (P) bioavailability (Expt. 3) in RSM, and effect of RSM inclusion on growth performance of broilers (Expt. 4). For Expt. 1, diets with 300 g/kg RSM from 11 RSM and 4 RSE varieties were fed to broilers from d 14 to 21, with excreta collection on d 19 to 21. Each treatment had 8 replicates and 3 birds per replicate. Energy metabolizability of RSM of a specialized high glucosinolate variety (V275OL) was greater (P < 0.05) than all the other varieties. In Expt. 2, two RSM varieties were processed with mild or conventional processing condition. There were no variety effects on ME, but ME and MEn were greater (P < 0.01) for RSM processed by mild processing condition. In Expt. 3, P bioavailability of RSM was determined, relative to MSP, using growth performance and tibia ash as responses. Phosphorus relative bioavailability values were greater (P < 0.05) in RSM of DK Cabernet variety processed using the mild processing condition. In Expt. 4, two RSM varieties were added to wheat-soybean meal-based diet at the rates of 50, 100, 150, or 200 g/kg and fed to broilers from d 0 to 42. Inclusion of 150 and 200 g/kg of RSM resulted in reduced weight gain and increased feed conversion ratio (FCR) compared (P < 0.01) with the lower inclusion levels during the starter phase. For the entire trial (d 0 to 42), weight gain was greater (P < 0.01) for birds receiving diets with RSM from PR46W21 variety. It was concluded from the experiments that apart from the residual ether extract content, variety differences had no impact on ME of RSM, conventional processing reduced ME and relative bio-availability of P; and that the maximum level of RSM inclusion depends on maximum growth performance level desired.


Subject(s)
Brassica napus/chemistry , Chickens/growth & development , Chickens/metabolism , Nutritive Value , Phosphorus/metabolism , Animal Feed/analysis , Animal Nutritional Physiological Phenomena/drug effects , Animals , Biological Availability , Diet/veterinary , Dietary Supplements/analysis , Energy Metabolism/drug effects , Male , Random Allocation
5.
Sci Total Environ ; 607-608: 443-453, 2017 Dec 31.
Article in English | MEDLINE | ID: mdl-28704670

ABSTRACT

This paper presents the results of an investigation into the processes controlling development of a cryo-conditioned rock coast system in Hornsund, Svalbard. A suite of nested geomorphological and geophysical methods have been applied to characterise the functioning of rock cliffs and shore platforms influenced by lithological control and geomorphic processes driven by polar coast environments. Electrical resistivity tomography (ERT) surveys have been used to investigate permafrost control on rock coast dynamics and reveal the strong interaction with marine processes in High Arctic coastal settings. Schmidt hammer rock tests, demonstrated strong spatial control on the degree of rock weathering (rock strength) along High Arctic rock coasts. Elevation controlled geomorphic zones are identified and linked to distinct processes and mechanisms, transitioning from peak hardness values at the ice foot through the wave and storm dominated scour zones to the lowest values on the cliff tops, where the effects of periglacial weathering dominate. Observations of rock surface change using a traversing micro-erosion meter (TMEM) indicate that significant changes in erosion rates occur at the junction between the shore platform and the cliff toe, where rock erosion is facilitated by frequent wetting and drying and operation of nivation and sea ice processes (formation and melting of snow patches and icefoot complexes). The results are synthesised to propose a new conceptual model of High Arctic rock coast systems, with the aim of contributing towards a unifying concept of cold region landscape evolution and providing direction for future research regarding the state of polar rock coasts.

6.
J Anim Physiol Anim Nutr (Berl) ; 101(4): 658-666, 2017 Aug.
Article in English | MEDLINE | ID: mdl-27562881

ABSTRACT

Rapeseed proteins have been considered as being poorly digestible in the gut of non-ruminants. The aim of the study was to assess the digestibility of napin and cruciferin in ileal digesta of broiler chickens, testing sixteen samples of rapeseed co-products with protein levels ranging from 293 g/kg to 560 g/kg dry matter. Each sample was included into a semi-synthetic diet at a rate of 500 g/kg and evaluated with broiler chickens in a randomised design. Dietary and ileal digesta proteins were extracted and identified by gel-based liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three isomers of napin (a 2S albumin) and nine cruciferins (an 11S globulin) were identified in the rapeseed co-products, whereas six endogenous enzymes such as trypsin (I-P1, II-P29), chymotrypsin (elastase and precursor), carboxypeptidase B and α-amylase were found in the ileal digesta. It is concluded that as none of the rapeseed proteins were detected in the ileal digesta, rapeseed proteins can be readily digested by broiler chickens, irrespective of the protein content in the diet.


Subject(s)
2S Albumins, Plant/metabolism , Animal Feed/analysis , Antigens, Plant/metabolism , Brassica rapa/chemistry , Chickens/metabolism , Seed Storage Proteins/metabolism , 2S Albumins, Plant/chemistry , Animal Nutritional Physiological Phenomena , Animals , Antigens, Plant/chemistry , Diet/veterinary , Male , Seed Storage Proteins/chemistry
7.
Sci Rep ; 6: 22367, 2016 Mar 14.
Article in English | MEDLINE | ID: mdl-26971711

ABSTRACT

An inherent element of research and applications in photonics is a beam of light. In magnonics, which is the magnetic counterpart of photonics, where spin waves are used instead of electromagnetic waves to transmit and process information, the lack of a beam source limits exploration. Here, we present an approach enabling generation of narrow spin wave beams in thin homogeneous nanosized ferromagnetic films by microwave current. We show that the desired beam-type behavior can be achieved with the aid of a properly designed coplanar waveguide transducer generating a nonuniform microwave magnetic field. We test this idea using micromagnetic simulations, confirming numerically that the resulting spin wave beams propagate over distances of several micrometers. The proposed approach requires neither inhomogeneity of the ferromagnetic film nor nonuniformity of the biasing magnetic field. It can be generalized to different magnetization configurations and yield multiple spin wave beams of different width at the same frequency.

8.
Phlebology ; 31(2): 125-32, 2016 Mar.
Article in English | MEDLINE | ID: mdl-25632064

ABSTRACT

OBJECTIVES: Although leukocyte elastase is suspected to be involved in the damage of vein wall during chronic venous disease, the equilibrium between this protease and its inhibitor, alpha1-antitrypsin, has not yet been evaluated. The aim of the present study was to determine the relationship between leukocyte elastase and alpha1-antitrypsin, in the blood of patients with chronic venous disease. PATIENTS AND METHODS: The concentration and the activity of leukocyte elastase along with the activity of alpha1-antitrypsin were evaluated in the blood of 55 chronic venous disease patients. The results were compared with those obtained in 33 healthy age and sex-matched volunteers. RESULTS: A significant decrease in the leukocyte elastase activity that correlated with an increased alpha1-antitrypsin activity was observed in the serum of patients with mild clinical symptoms of chronic venous disease. CONCLUSIONS: The results of the study did not confirm a hypothesis about an important role of proteolytic activity of leukocyte elastase in the vein wall injury mechanism. They show that the leukocyte elastase-alpha1-antitrypsin balance is rather shifted toward antiprotease activity, especially in an early stage of chronic venous disease.


Subject(s)
Leukocyte Elastase/blood , Vascular Diseases/blood , alpha 1-Antitrypsin/blood , Adult , Aged , Chronic Disease , Female , Humans , Male , Middle Aged
9.
Phys Rev Lett ; 115(16): 162502, 2015 Oct 16.
Article in English | MEDLINE | ID: mdl-26550870

ABSTRACT

We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a |B0|=1 µT magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method takes advantage of the relative dephasing of spins arising from a gravitationally induced striation of stored UCNs of different energies, and also permits an improved determination of the vertical magnetic-field gradient with an exceptional accuracy of 1.1 pT/cm. This novel combination of a well-known nuclear resonance method and gravitationally induced vertical striation is unique in the realm of nuclear and particle physics and should prove to be invaluable for the assessment of systematic effects in precision experiments such as searches for an electric dipole moment of the neutron or the measurement of the neutron lifetime.


Subject(s)
Gravitation , Models, Theoretical , Neutrons , Cold Temperature , Kinetics
10.
J Food Sci Technol ; 52(10): 6663-70, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26396414

ABSTRACT

The effect of everlasting pea in combination with wheat on physical properties and microstructure of extrudates were studied. The share of everlasting pea (Lathyrus sativus) was variable, at 35, 50 and 65 %, respectively. The everlasting pea-wheat mixtures were moistened to the required level (18, 21, and 24 %), homogenized, conditioned and extruded in twin-screw extruder with counter-rotating conical screws. All of the obtained extrudates were characterised by a slow degree of radial expansion and high specific density. The Pearson correlation analysis indicated a statistically significant linear Pearson correlation (p < 0.05) between chemical compositions of the blends and physical properties of the extrudates. The expansion ratio increased as the concentration of the fibers and proteins increased, while specific density and hardness decreased. Inverse relationship was observed for crude fat. The microstructure of the extrudates was determined by both the moisture of the blend and the process temperature. The differences observed in the size, number of air cells and in the cell wall shapes and thickness indicate possibilities of the modification of physical properties of everlasting pea-wheat extrudates. The extrudates produced from everlasting pea-wheat blends (50:50) at higher barrel temperature (110/140/180/170/130 °C) were characterised by more numerous air cells of smaller diameters. Increasing moisture content of extruded blends results in extrudates with a higher porosity. No significant effect was shown in the chemical compositions on the level of metal contamination in the extrudates. The application of a counter-rotating twin-screw extrusion-cooker in the study permitted the production of compact, hard everlasting pea-wheat extrudates for use in vegetarian lunch dishes.

11.
Opt Express ; 23(17): 22108-15, 2015 Aug 24.
Article in English | MEDLINE | ID: mdl-26368184

ABSTRACT

We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of a 1 µT magnetic field. Multiple circularly polarized laser beams were used to probe the free spin precession of the Cs atoms. The design was optimized for long-time stability and achieves a scalar resolution better than 300 fT for integration times ranging from 80 ms to 1000 s. The best scalar resolution of less than 80 fT was reached with integration times of 1.6 to 6 s. We were able to measure the magnetic field direction with a resolution better than 10 µrad for integration times from 10 s up to 2000 s.

12.
Transplant Proc ; 45(4): 1567-70, 2013 May.
Article in English | MEDLINE | ID: mdl-23726621

ABSTRACT

BACKGROUND: Cardiovascular mortality in renal transplant recipients is nearer 10-fold higher than in general population. Immunosuppressive therapy is one possible cause, for these drugs can modify cardiovascular risk factors, which can induce endothelial dysfunction, the first step in the process of atherosclerosis. The aim of this study was to compare vasodilatatory function of endothelium in renal transplant recipients in relation to the immunosuppressive drug-cyclosporine or tacrolimus. MATERIALS AND METHODS: We examined 40 patients at 48.9 ± 36 months post-renal transplantation: 22 taking tacrolimus (group 1) and 18 taking cyclosporine (group 2). The renal transplant recipients were compared with a control group of 18 healthy people. Endothelial function was assessed by peripheral arterial tonometry (PAT) using the EndoPAT 2000 device to measure RHI (reactive hyperemia index) and AI% (augmentation index%). RESULTS: The overall median values of RHI were higher than the value accepted as a normal (1.67). The RHI median value in group 1 was 2.00 (quartile 1: 1.66; quartile 2: 2.72), not different from that in group 2 [1.90 (quartile 1: 1.56; quartile 2: 2.17)] or the controls [2.11 (quartile 1: 1.77; quartile 2: 2.50)]. Multivariate analysis revealed age to be the independent factor influencing RHI in all examined groups but treatment with calcium channel blockers appeared to be the only independent factor influencing RHI among renal transplant recipients. AI% values were not significantly different between the 2 groups of renal transplant recipients, but it was significantly higher among the controls than among subjects treated with tacrolimus. CONCLUSIONS: Vasodilatatory function of endothelium assessed by PAT in renal transplant recipients was not worse than in healthy people. It was not different between cyclosporine or tacrolimus. Arterial stiffness measured as AI% depend on age but not the calcineurin inhibitor, which showed little effect.


Subject(s)
Cyclosporine/administration & dosage , Endothelium, Vascular/drug effects , Hyperemia/physiopathology , Immunosuppressive Agents/administration & dosage , Kidney Transplantation , Tacrolimus/administration & dosage , Adult , Case-Control Studies , Cyclosporine/pharmacology , Endothelium, Vascular/physiopathology , Female , Humans , Immunosuppressive Agents/pharmacology , Male , Middle Aged , Tacrolimus/pharmacology
13.
J Phys Condens Matter ; 25(24): 245401, 2013 Jun 19.
Article in English | MEDLINE | ID: mdl-23709492

ABSTRACT

The elastic properties of fcc Fe-Mn-X (X = Cr, Co, Ni, Cu) alloys with additions of up to 8 at.% X were studied by combinatorial thin film growth and characterization and by ab initio calculations using the disordered local moments (DLM) approach. The lattice parameter and Young's modulus values change only marginally with X. The calculations and experiments are in good agreement. We demonstrate that the elastic properties of transition metal alloyed Fe-Mn can be predicted by the DLM model.


Subject(s)
Alloys/chemistry , Elasticity , Iron/chemistry , Magnesium/chemistry , Metals, Heavy/chemistry , Quantum Theory , Chromium/chemistry , Cobalt/chemistry , Copper/chemistry , Nickel/chemistry
14.
J Anim Sci ; 90 Suppl 4: 384-6, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23365387

ABSTRACT

External markers for determination of nutrient digestibility have often been evaluated in conventional dry feeds but less often in conventional feeds such as human-type diets used in animal model studies. In the present study, 5 ileal-cannulated pigs were fed 5 types of soft bread-based diets supplemented with Cr(2)O(3) and AIA as digestibility markers for 1 wk in a Latin square design. Ileal contents were collected twice for 5 h and a fecal grab sample was obtained once per week. Ileal and total tract digestibility of OM and nonstarch polysaccharides (NSP) based on the 2 markers were compared by linear regression. Across dietary treatments and site of collection, high correlation existed between digestibility values obtained with Cr(2)O(3) and AIA, resulting in a R(2) > 0.77 (P < 0.001) and a linear relation close to unity. For ileal samples, the correlation was poor, particularly for NSP, which had R(2) = 0.09 (P = 0.14) whereas OM had an R(2) = 0.52 (P <0.001). On the other hand, fecal grab samples led to R(2) > 0.92 (P < 0.001) for both OM and NSP. However, AIA gave higher values than Cr(2)O(3), particularly in samples with lower digestibility. The discrepancy is presumably caused by analytical difficulties due to a high fecal ash contents or interference with other components in the human-type diets.


Subject(s)
Animal Feed/analysis , Diet/veterinary , Swine/physiology , Animal Nutritional Physiological Phenomena , Animals , Biomarkers , Bread , Chromium Compounds/pharmacology , Digestion/physiology , Humans
15.
Cancer Gene Ther ; 18(5): 346-57, 2011 May.
Article in English | MEDLINE | ID: mdl-21233855

ABSTRACT

Cancer treatment is often complicated by resistance to conventional anti-cancer treatment and to more recently developed immunotherapy and gene therapy. These therapeutic modalities aim at activating death pathways within cancer cells. Attempts to activate the apoptotic death pathway, by overexpressing proapoptotic signals, are compromised by cancer defense mechanisms, which disrupt the apoptotic-signaling cascade downstream of the overexpressed component. Here, we describe a therapeutic option of triggering apoptosis without activating the apoptotic-signaling cascade or using the native apoptosis executioner nuclease. We have engineered Deoxyribonuclease-1 (DNase1), a waste-management enzyme, by deleting its signal peptide, adding a nuclear localization signal, and mutating its actin-binding site. Apoptosis studies and colony-forming assay for assessing cell viability were conducted in apoptosis-resistant Mel-Juso human melanoma cells. The modified DNase1 reduced cell viability by 77% relative to controls. It also induced typical microscopic features of cellular apoptosis, such as Terminal Transferase dUTP Nick-End Labeling-positive cells and DNA fragmentation. Quantification of apoptosis by Laser scanning cytometry demonstrated high-killing efficiency of 70-100%. The results suggest that this modified DNase1 can efficiently eliminate apoptosis-resistant cancer cells through apoptosis. Coupled to different tissue-specific gene expression elements, this recombinant DNase1 may serve as a platform for eliminating a variety of cancer types.


Subject(s)
Apoptosis/physiology , Deoxyribonuclease I/metabolism , Genetic Therapy/methods , Melanoma/therapy , Protein Engineering/methods , Signal Transduction/physiology , Apoptosis/genetics , Cell Line, Tumor , Colony-Forming Units Assay , DNA Fragmentation , Humans , In Situ Nick-End Labeling , Laser Scanning Cytometry , Melanoma/genetics , Signal Transduction/genetics
16.
Phys Rev Lett ; 99(16): 161603, 2007 Oct 19.
Article in English | MEDLINE | ID: mdl-17995237

ABSTRACT

In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n', could potentially mix and undergo nn' oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the n' amplitude in the n wave function and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time taunn' > 103 s (95% C.L.) is derived.

17.
Phys Rev Lett ; 99(26): 262502, 2007 Dec 31.
Article in English | MEDLINE | ID: mdl-18233572

ABSTRACT

A measurement of the production of ultracold neutrons from velocity-selected cold neutrons on gaseous and solid deuterium targets is reported. The expected energy dependence for two-particle collisions with well defined neutron and Maxwell-Boltzmann distributed molecular velocities is found for the gas target. The solid target data agree in shape with the phonon density-of-states curve and provide strong evidence for the phonon model including multiphonon excitations.

18.
Phys Rev Lett ; 95(18): 182502, 2005 Oct 28.
Article in English | MEDLINE | ID: mdl-16383898

ABSTRACT

The total scattering cross sections for slow neutrons with energies in the range 100 neV to 3 meV for solid ortho-2H2 at 18 and 5 K, frozen from the liquid, have been measured. The 18 K cross sections are found to be in excellent agreement with theoretical expectations and for ultracold neutrons dominated by thermal up scattering. At 5 K the total scattering cross sections are found to be dominated by the crystal defects originating in temperature induced stress but not deteriorated by temperature cycles between 5 and 10 K.

19.
Phys Rev Lett ; 94(21): 212502, 2005 Jun 03.
Article in English | MEDLINE | ID: mdl-16090315

ABSTRACT

The total scattering cross sections for slow neutrons with energies E in the range 300 neV to 3 meV for gaseous and liquid ortho-2H2 have been measured. The cross sections for 2H2 gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid 2H(2), we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear 1 / square root[E'] dependence at low energies for both states. A simple explanation for the liquid 2H2 cross section is offered.

20.
J Res Natl Inst Stand Technol ; 110(3): 173-8, 2005.
Article in English | MEDLINE | ID: mdl-27308117

ABSTRACT

For highly sensitive magnetic measurements, e.g., a measurement of the neutron electric dipole moment (EDM), the magnetic field has to be stable in time on a level below picoTesla. One of several measures we employ to achieve this uses an external field coil system which can stabilize the ambient external field at a predefined value. Here we report on the construction and characterization of such a system in the magnetic test facility at PSI. The system actively stabilizes the field along the axis of the EDM experiment by means of four coils in a Helmholtz-like configuration. Additional coils serve to compensate for transverse ambient field components. Because of the long integration times in the EDM experiment (about 100 s or more) only slow disturbances have to be corrected for. The performance of the system has been measured using static and moving magnetic sources and suppression factors in excess of 200 have been observed.

SELECTION OF CITATIONS
SEARCH DETAIL
...