Continuous arterial spin labeling (CASL) in the monkey brain at high magnetic field using a three-coil approach

CASL experiments in the monkey brain were performed at 4.7 T and 7 T using a separate labeling coil. Increased sensitivity and SNR were achieved by a custom-made three-coil setup and high magnetic field with its increased T1. We report the development and optimization of the setup and first experiments in the monkey (macaca mulatta). Parameters for continuous labeling (label power, label duration, post label delay) were optimized to measure gray matter rCBF and fCBF changes, reporting excellent multi-slice coverage at high resolution of 0.75 – 1 mm in-plane

Perfusion-based functional imaging in the monkey brain at 7T: investigations of CASL parameters

Perfusion-based imaging in the monkey primary visual cortex was performed at 7 T applying continuous arterial spin labeling (CASL). Increased perfusion sensitivity and SNR at high magnetic field (due to larger T1) was further optimized using a custom-made three-coil setup with a separate neck labeling coil. We investigated the labeling parameters to obtain relative fCBF changes in the anaesthetized monkey. We report excellent functional activation of striate cortex at high resolution of 0.75x0.9mm2 in-plane. Interestingly, the optimal parameter set for obtaining highest signal changes of rCBF are different from the reported values for imaging gray matter CBF

Fiske steps and hysteresis in YBa2Cu3O7 grain boundary Josephson junctions: Structural Information of the barrier by means of a nondestructive approach.

A deep analysis of the current-voltage _I-V_ characteristics of YBa2Cu3O7 grain boundary Josephson junctions _GBJJs_ allows us to go much farther than the usual calculus of the transport parameters. It is possible to construct a structural image of the barrier by an exhaustive and complementary analysis of both transport and electromagnetic parameters obtained from I-V curves. For such an approach, we have chosen the following three representative bicrystalline geometries: 24° _001_ asymmetric, 45° _100_ asymmetric, and 24° _001_ symmetric +45° _100_ asymmetric. The dependence of the product ICRN on the junction normal resistance is of the ICRN −1 type pointing to a SNINS model _S denotes superconductor, I denotes insulator, and N denotes normal metal_ for all our GBJJs. A satisfactory explanation of the discrepancy of the capacitance of the barrier estimated from Fiske resonance positions and hysteresis in the I-V curves needs of such a model. Moreover an estimation of the length of the normal regions adjacent to the crystallographic barrier can be made. This comparative analysis is presented in order to extract interesting information about the particular transport mechanisms involved in these GBJJs

Long-term prognosis of nerve palsy after total hip arthroplasty: results of two-year-follow-ups and long-term results after a mean time of 8years

Introduction: Nerve damage is a rare but serious complication after THA. There exist only little data about the outcome of these patients particularly regarding the long-term results later than 2years postoperatively. Aim of this study is to answer the following questions: Is the recovery to be expected for light nerve lesions different from the severe ones? Is there a possibility of nerve recovery more than 2years after THA? Is the potential of nerve recovery depending on the affected nerve? Materials and methods: This study investigates 2,255 primary THA as well as revision surgeries performed from 1988 to 2003 relating to iatrogenic nerve lesion. We classified the nerve lesion according to the core muscle strength in severe (M0-M2) and light (M3-M4) nerve damage and differentiated between femoral, sciatic and superior gluteal nerve, according to the electromyography. Results: We found 34 cases of iatrogenic nerve damage representing an incidence of 1.5%. 17 of 34 (50%) patients showed a complete recovery after 2years. Out of the remaining 17 patients, six out of seven patients with a final examination after a median time of 93months achieved further improvement. The different nerves showed no significant different potential of recovery. Conclusions: In contrast to the literature, an improvement beyond the limit of 2years is probable and independent of the nerve affected

Resonant Steps in the Characteristics of a Josephson Junction Coupled to a Transmission Line

A novel circuit is described which functions as an electronic analog of lumped element transmission line. The circuit requires only operational amplifiers, resistors, and capacitors. This module was coupled to a Josephsonj unction simulator and current voltage characteristics of the combined system were recorded. Steps were observed at voltages determined by the appropriate line resonances. When the transmission line was terminated with loads less than the characteristic impedance, chaos was seen in the lower steps. Similar results were obtained by numerical integration of the corresponding system of differential equations

Amlodipine+Benazepril is Superior to Hydrochlorothiazide+Benazepril Irrespective of Baseline Pulse Pressure: Subanalysis of the ACCOMPLISH Trial

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110751/1/jch12460.pd

Prior Medications and the Cardiovascular Benefits From Combination Angiotensin‐Converting Enzyme Inhibition Plus Calcium Channel Blockade Among High‐Risk Hypertensive Patients

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142520/1/jah32856_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142520/2/jah32856.pd

Advanced code-division multiplexers for superconducting detector arrays

Multiplexers based on the modulation of superconducting quantum interference devices are now regularly used in multi-kilopixel arrays of superconducting detectors for astrophysics, cosmology, and materials analysis. Over the next decade, much larger arrays will be needed. These larger arrays require new modulation techniques and compact multiplexer elements that fit within each pixel. We present a new in-focal-plane code-division multiplexer that provides multiplexing elements with the required scalability. This code-division multiplexer uses compact lithographic modulation elements that simultaneously multiplex both signal outputs and superconducting transition-edge sensor (TES) detector bias voltages. It eliminates the shunt resistor used to voltage bias TES detectors, greatly reduces power dissipation, allows different dc bias voltages for each TES, and makes all elements sufficiently compact to fit inside the detector pixel area. These in-focal-plane code-division multiplexers can be combined with multi-gigahertz readout based on superconducting microresonators to scale to even larger arrays.Comment: 8 pages, 3 figures, presented at the 14th International Workshop on Low Temperature Detectors, Heidelberg University, August 1-5, 2011, proceedings to be published in the Journal of Low Temperature Physic