1,790 research outputs found
Towards high-energy neutrino astronomy
No full textThe search for the sources of cosmic rays is a three-fold assault, using charged cosmic
rays, gamma rays and neutrinos. The first conceptual ideas to detect high energy neutrinos
date back to the late fifties. The long evolution towards detectors with a realistic
discovery potential started in the seventies and eighties, with the pioneering works in
the Pacific Ocean close to Hawaii and in Lake Baikal in Siberia. But only now, half a
century after the first concepts, such a detector is in operation: IceCube at the South
Pole. We do not yet know whether with IceCube we will indeed detect extraterrestrial high
energy neutrinos or whether this will remain the privilege of next generation telescopes.
But whatever the answer will be: the path to the present detectors was a remarkable
journey. This review sketches its main milestones
Binding Kinetics of Bisintercalator Triostin A with Optical Tweezers Force Mechanics
No full textKleimann C, Sischka A, Spiering A, et al. Binding Kinetics of Bisintercalator Triostin A with Optical Tweezers Force Mechanics. Biophysical Journal. 2009;97(10):2780-2784.The binding kinetics of the intercalative binding of Triostin A to A-DNA was investigated by measuring the force extension response of the DNA-ligand complexes with an optical tweezers system. These force response curves, containing the information about different binding properties, were analyzed based on a recent method (put forth by another research group) for monointercalators that was extended to bisintercalators. Our binding analysis reveals an exponential dependence of the association constant on the applied external force as well as a decreasing binding site size. In general, our results are in agreement with those for the monointercalator ethidium. However, to explain the high-force binding site size, a new model for bisintercalation of Triostin A at high forces is proposed
Development of a goniometer stage for single crystal Mössbauer measurements
No full textAbstract 3.10.f
Advances in Mössbauer Emission-Spectroscopy
No full textSpiering H, Alflen M, Gütlich P, et al. Advances in Mössbauer Emission-Spectroscopy. HYPERFINE INTERACTIONS. 1990;53(1-4):113-141
Evidence for IHA migration during axial rotation of a lumbar spine segment by using a novel high-resolution 6D kinematic tracking system
No full textThe biomechanical properties of the lumbar spine have long been studied. However, despite its enormous importance, basic functional and morphological properties have been not well understood and require further experimental analysis since data concerning the spatial instantaneous segmental motions are hardly available. This study describes the theoretical background and the technical properties of an innovative method for tracking the instantaneous 3D motion of human spinal segments in vitro at high spatial resolution. This new acquisition system allows to scrutinise closely the location and alignment of the segmental instantaneous helical axis (IHA) and the respective screw pitch as functions of the absolute rotational angle. The required precision of the measuring device was attained (a) by six highly resolving linear inductive displacement sensors in a special spatially configuration (3-2-1), (b) by a method to apply torque and force independently of each other without counteraction, and (c) by suppression of vibrations. The validity and reliability of the experimental set-up and the numerical method of data analysis were tested by subjects of known mechanical properties. In vitro experiments with a human lumbar segment (L3/L4, autopsy material) demonstrated that (a) the IHA migrated during axial rotation from one segmental articulatio zygapophysialis to the other joint, (b) the IHA tilted medial-laterally, and (c) the pitch of the screw altered linearly as a function of the rotational angle. This phenomenon is traced back to the guidance of the articluationes zygapophysiales. The validation of the method allows to map segments of the entire vertebral column. The results can be used as benchmarks for future models of the human spine. (C) 2003 Elsevier Ltd. All rights reserved
How do spinal segments move?
No full textPurpose: To study and clarify the kinematics of spinal segments following cyclic torques causing axial rotation (T(z) (t)), lateral-flexion (T(x) (t)). flexion/extension (T(y) (t)) Methods A 6D--Measurement of location, alignment, and migration of the instantaneous helical axis (IHA) as a function of rotational angle in cervical, thoracic, and lumbar segments subjected to axially directed preloads. Results: IHA retained an almost constant alignment, but migrated along distinct centrodes. Thoracic segments: IHA was almost parallel to T(z) (t), T(x) (t), or T(y) (t), stationary for T(x) (t) or T(y) (t), and migrating for T(z) (t) along dorsally opened bows. IHA locations hardly depended on the position or size of axial preload. Lumbar segments: IHA was also almost parallel to T(z) (t), T(x) (t), or T(y) (t) In axial rotation IHA-migration along wide, ventrally or dorsally bent bows depending on segmental flexional/extensional status. Distances covered: 20-60 mm In lateral-flexion: IHA-migration to the left/right joint and vice versa. In flexion/extension IHA-migration from the facets to the centre of the disc. Cervical segments: In flexion/flexion IHA was almost stationary for and parallel to T(y) (t). In axial rotation or lateral-flexion IHA intersected T(z) (t)/T(x) (t) under approximately -30'/+30. Conclusions: Generally joints alternate in guidance Lumbar segments. in axial rotation and lateral-flexion parametrical control of IHA-position and IHA-migration by axial preload position. Cervical segments: kinematical coupling between axial rotation and lateral-flexion. The IHA-migration guided by the joints should be taken into account in the design of non-fusion implants. FE-calculations of spinal mechanics and kinematics should be based on detailed data of curvature morphology of the articulating surfaces of the joint facets. (C) 2009 Elsevier Ltd. All rights reserved
Mixed spin-state [HS-LS] pairs in a dinuclear spin-transition complex: confirmation by variable-temperature 57Fe Mössbauer spectroscopy
No full textExquisite sensitivity of Mössbauer spectroscopy for tiny local molecular distortion is demonstrated in [FeII2(pmat)2](BF4)4?DMF: high-spin (HS) iron(II) in [HS-HS] and in [LS-HS] (low-spin–high-spin) pairs is clearly distinguished (see picture) for the first time without the need to apply a magnetic field. This dinuclear complex clearly shows that spin crossover via a [LS-HS] species is promoted by the use of a highly constrained bridging ligand (the bis-terdentate pmat)
Frolockender Glücks-Wunsch, Als Ihro Königliche Hoheit ... Herr Adolph Friederich, Erbe zu Norwegen, Bischoff zu Lübeck, Hertzog und Administrator zu Schleßwig und Hollstein, [et]c. [et]c. Zu einem Erb-Printzen und Kron-Folger des Königreichs Schweden Von denen Reichs-Ständen einmüthigst erwehlet wurden
No full textFROLOCKENDER GLÜCKS-WUNSCH, ALS IHRO KÖNIGLICHE HOHEIT ... HERR ADOLPH FRIEDERICH, ERBE ZU NORWEGEN, BISCHOFF ZU LÜBECK, HERTZOG UND ADMINISTRATOR ZU SCHLESSWIG UND HOLLSTEIN, [ET]C. [ET]C. ZU EINEM ERB-PRINTZEN UND KRON-FOLGER DES KÖNIGREICHS SCHWEDEN VON DENEN REICHS-STÄNDEN EINMÜTHIGST ERWEHLET WURDEN
Frolockender Glücks-Wunsch, Als Ihro Königliche Hoheit ... Herr Adolph Friederich, Erbe zu Norwegen, Bischoff zu Lübeck, Hertzog und Administrator zu Schleßwig und Hollstein, [et]c. [et]c. Zu einem Erb-Printzen und Kron-Folger des Königreichs Schweden Von denen Reichs-Ständen einmüthigst erwehlet wurden ( - )
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Inhaltsverzeichnis des Sammelbandes und Provenienzvermerk ( - )
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Der wohlgetroffne Wett-Streit, Bey der höchst-erfreulichen Schwedischen Thron-Wahl Ihro Königl. Hoheit Herrn Adolph Friedrich, Hertzog von Schleßwig-Hollstein/ [et]c. [et]c. auf dem Hamburgischen Schau-Platze in einem Sing-Spiele vorgestellt
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