Search Results

You are looking at 1 - 10 of 12 items for

  • Author or Editor: M. Becker x
  • Refine by Access: All Content x
Clear All Modify Search

Abu-Dabbab area is characterized by high seismicity and complex tectonic setting, for these facts, a local geodetic network consisting of eleven geodetic benchmarks has been established. The crustal deformation data in this area are collected using the GPS techniques. Five campaigns of GPS measurements have been collected, processed and adjusted to get the more accurate positions of the GPS stations. The horizontal velocity vectors, the dilatational, the maximum shear strains and the principal strain rates were estimated. The magnitude of the movements is distributed inhomogeneous over the area and it varies in average between 3 and 6 mm/yr. The results of the deformation analyses indicate a significant contraction and extension across the southern central part of the study area which is characterized by high seismic activity represented by the clustering shape of the microearthquakes that trending NE-SW direction. The north and north-eastern parts are characterized by small strain rates. This study is an attempt to provide valuable information about the present state of the crustal deformation and its relationship to seismic activity and tectonic setting at Abu-Dabbab area.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
Anna Kropidłowska
,
M. Strankowski
,
Maria Gazda
, and
Barbara Becker

Abstract  

The thermal behavior of Mn(II) silanethiolate series [Mn(SR)2L(MeOH)n], where R=SSi(OBut)3, L=heterocyclic nitrogen base and n=0, 1 or 2 has been comparatively investigated using differential scanning calorimetry (DSC), thermogravimetry (TG) and TG-infrared spectoscopy (IR) techniques. The TG curves indicate the differences in the thermal decomposition due to presence of distinct N-donor ligands and labile MeOH molecules coordinated to the central atom. The first step on the TG curves (60–110C) corresponds to the elimination of alcohol from respective complexes. The main step (150–350C) can be assigned to the decomposition of the complexes yielding Mn3O4 and silica as the main final products, identified by X-ray diffraction patterns.

Restricted access

Abstract  

Thermal properties of seed proteins, prolamines from rice, wheat and soybean were studied by differential scanning calorimetry (DSC), thermogravimetry (TG), thermal expansion, X-ray diffraction and infrared spectroscopy. Prolamine films cast from aqueous ethanol are amorphous in the random-coil conformation. The glass transition of prolamine is observed at 160, 172 and 150C for rice, wheat and soybean, respectively. The amorphous prolamine films crystallize at 196, 205 and 199C for rice, wheat and soybean, respectively. The thermal degradation of prolamine films occurs from 228, 250 and 270C for rice, wheat and soybean, respectively.

Restricted access

Abstract  

The Preparatory Commission of Comprehensive Nuclear Test-Ban-Treaty Organization is setting up a global network capable to monitor treaty compliance. Specific monitoring systems and methodologies that match the needs of the International Monitoring System (IMS), namely to clarify the nuclear character of suspect explosions, had to be developed for monitoring purposes during the last decade. Four xenon isotopes, namely 133Xe, 135Xe, 133mXe and 131mXe play a key role here. A complex background from medical isotope production facilities and nuclear power plants, varying over four orders of magnitude, challenges the system’s capability to distinguish these from treaty-relevant events. Available measurement data are compared with model calculations. The importance of atmospheric transport modelling is demonstrated both for completely understanding the civilian background and for explaining peak concentrations and abnormal events. New methodologies for backtracking nuclide detections improved the capability to locate sources and corroborate the role of radioxenon monitoring.

Restricted access

Heteroleptic cadmium(II) complex, potential precursor for semiconducting CDS layers

Thermal stability and non-isothermal decomposition kinetics

Journal of Thermal Analysis and Calorimetry
Authors:
Anna Kropidłowska
,
A. Rotaru
,
M. Strankowski
,
Barbara Becker
, and
E. Segal

Abstract  

Coordination compounds may be used as efficient precursors for fabrication of semiconducting layers. Thermal stability of such a potential precursor — [Cd{SSi(O-tBu)3}(S2CNEt2)]2 — was investigated (tBu means tert-butyl and Et means ethyl). The kinetic study was performed by means of different multi-heating rate methods: isoconversional (Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Friedmann) methods associated with the criterion of the independence of the activation parameters on the heating rate. The kinetic triplet of the non-isothermal decomposition of this Cd(II) complex was established.

Restricted access
Journal of Behavioral Addictions
Authors:
Fangwen Yu
,
Jialin Li
,
Lei Xu
,
Xiaoxiao Zheng
,
Meina Fu
,
Keshuang Li
,
Shuxia Yao
,
Keith M. Kendrick
,
Christian Montag
, and
Benjamin Becker

Abstract

Background

Accumulating evidence suggests brain structural and functional alterations in Internet Use Disorder (IUD). However, conclusions are strongly limited due to the retrospective case-control design of the studies, small samples, and the focus on general rather than symptom-specific approaches.

Methods

We here employed a dimensional multi-methodical MRI-neuroimaging design in a final sample of n = 203 subjects to examine associations between levels of IUD and its symptom-dimensions (loss of control/time management, craving/social problems) with brain structure, resting state and task-based (pain empathy, affective go/no-go) brain function.

Results

Although the present sample covered the entire range of IUD, including normal, problematic as well as pathological levels, general IUD symptom load was not associated with brain structural or functional alterations. However, the symptom-dimensions exhibited opposing associations with the intrinsic and structural organization of the brain, such that loss of control/time management exhibited negative associations with intrinsic striatal networks and hippocampal volume, while craving/social problems exhibited a positive association with intrinsic striatal networks and caudate volume.

Conclusions

Our findings provided the first evidence for IUD symptom-domain specific associations with progressive alterations in the intrinsic structural and functional organization of the brain, particularly of striatal systems involved in reward, habitual and cognitive control processes.

Open access
Journal of Behavioral Addictions
Authors:
Xinqi Zhou
,
Renjing Wu
,
Congcong Liu
,
Juan Kou
,
Yuanshu Chen
,
Halley M. Pontes
,
Dezhong Yao
,
Keith M. Kendrick
,
Benjamin Becker
, and
Christian Montag

Abstract

Background and aims

Growing concerns about the addictive nature of Internet and computer games led to the preliminary recognition of Internet Gaming Disorder (IGD) as an emerging disorder by the American Psychiatric Association (APA) and the official recognition of Gaming Disorder (GD) as a new diagnosis by the World Health Organization (WHO). While the definition of clear diagnostic criteria for (I)GD represents an important step for diagnosis and treatment of the disorder, potential neurobiological correlates of the criteria remain to be explored.

Methods

The present study employed a dimensional Magnetic Resonance Imaging (MRI) approach to determine associations between (I)GD symptom-load according to the APA and WHO diagnostic frameworks and brain structure in a comparably large sample of n = 82 healthy subjects.

Results

Higher symptom-load on both, the APA and WHO diagnostic frameworks convergently associated with lower volumes of the striatum.

Discussion

The results from this exploratory study provide the first initial evidence for a neurobiological foundation of the proposed diagnostic criteria for (I)GD according to both diagnostic classification systems and suggest that the transition from non-disordered to disordered gaming may be accompanied by progressive neuroplastic changes in the striatum, thus resembling progressive changes in other addictive disorders.

Conclusions

The proposed (I)GD criteria in both diagnostic systems were associated with neurostructural alterations in the striatum, suggesting an association with progressive changes in the motivational systems of the brain.

Open access

Abstract  

[18F]Florbetaben ([18F]BAY 94-9172) is a promising β-amyloid (Aβ) targeted PET-tracer currently in late stage clinical development. [18F]Florbetaben can assist in the more accurate diagnosis of Alzheimer’s Disease (AD) by non-invasive, in vivo detection of Aβ in the brain. To determine the arterial input function of the PET tracer—as part of a proof of mechanism (PoM) study—arterial samples were drawn from all subjects at predefined time points post injection (p.i.), and the proportion of unchanged tracer [18F]Florbetaben was determined by HPLC analysis. Plasma metabolite profiles were investigated following intravenous administration of 300 MBq (±60 MBq) of [18F]Florbetaben to both, patients with AD and healthy controls (HCs), and various methods for processing the blood samples were evaluated. Addition of acetonitrile to plasma samples (obtained from whole blood by centrifugation) and precipitation of proteins resulted in a recovery of more than 90% of the initial radioactivity in the supernatants. High Performance Liquid Chromatography using a polymer-based column (PRP-1) in conjunction with gradient elution was found to be a suitable method of metabolite analysis of [18F]Florbetaben. HPLC analyses indicated that [18F]Florbetaben is rapidly metabolized in vivo with an estimated initial half-life of about 6 min. A polar metabolite fraction, consisting presumably of more than one component, and (to a smaller extent) of the demethylated derivative of [18F]Florbetaben were time-dependently detected in plasma.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
T. Tanaka
,
J. Magoshi
,
Y. Magoshi
,
B. Lotz
,
S.-I. Inoue
,
M. Kobayashi
,
H. Tsuda
,
M. Becker
,
Zh. Han
, and
Sh. Nakamura

Abstract  

The crystal structure, thermal properties and growth rates of spherulites of the Tussah silk fibroin, produced upon drying of the silk taken directly from the lumen which is essentially a poly(L-alanine)polypeptide, are investigated. Depending on casting conditions, spherulites with either αhelical chain conformation or β parallel sheet structure are produced. The growth rates display a strong positive temperature coefficient, with an apparent transition, which however cannot be related with the formation of two different crystal structures at this stage.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
T. Tanaka
,
J. Magoshi
,
Y. Magoshi
,
S. ichi Inoue
,
M. Kobayashi
,
H. Tsuda
,
M. Becker
, and
Sh. Nakamura

Abstract  

The thermal properties of liquid silk from domestic and wild silkworms are investigated. Liquid silks obtained from the silk gland of the domesticated silkworm, Bombyx mori and four wild silkworms, Samia cynthia ricini, Dictyoploca japonica, Antheraea pernyi and Antheraea yamamai were used. The DSC curves for the liquid silk from the domestic silkworm have weak endothermic peaks corresponding to the breaking of hydrogen bonds in the β-form or to the untangling of physical network. The DSC curves for the wild silkworm silks, however, show clear exothermic peaks corresponding to a phase transition from the α-helix conformation to the β-form. Liquid silk from all the different silkworms undergoes a characteristic irreversible phase transition.

Restricted access