Gadolinium-enhanced magnetic resonance angiography of the pelvis in patients with erectile impotence

This study evaluted the potential of contrast-enhanced digital-subtraction magnetic resonance angiography (CE-DS-MRA) for noninvasive angiographic delineation of the arterial supply of the penis in patients with erectile dysfunction. After induction of an erection with prostaglandin E, a three-dimensional fast imaging with steady-state precision (FISP) sequence with TE of 1.8–2 milliseconds, TR of 4.4–5 milliseconds, and flip angle of 40°–60° was used to obtain high-resolution angiograms of the pelvis and penis during the injection of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) 0.3 mmol/kg body weight, within 30–50 seconds. DS maximum intensity projections (MIPs) and multiplanar reconstructions (MPRs) were compared with clinical work-up and directional Doppler ultrasound in 11 patients. In all 11 patients (100%), the arterial supply of the penis could be delineated from the aortic bifurcation via the iliac and internal pudendal arteries to the dorsal and deep penile arteries. Of the 22 internal pudendal arteries, 6 (27%) were occluded on CE-DS-MRA and 5 (23%) had stenoses, of which 4 (18%) were greater than 50%. In 7 patients (64%) good correlation between CE-DS-MRA and clinical findings and/or Doppler ultrasound was found; in 2 patients (18%), the correlation was moderate, and in 2 patients (18%) results were discrepant. In 6 patients (55%), MRA provided additional information to the clinical and Doppler ultrasound work-up. CE-DS-MRA can delineate small sessels such as the internal pudendal and penile arteries and thus has the potential to become a noninvasive angiography method in the work-up of erectile impotence. Supported by Siemens Medical Systems, Erlangen; Schering AG, Berlin; and Agfa-Gevaert AG, Leverkusen.     

Data partitioning and load balancing in parallel disk systems

Parallel disk systems provide opportunities for exploiting I/O parallelism in two possible ways, namely via inter-request and intra-request parallelism. In this paper, we discuss the main issues in performance tuning of such systems, namely striping and load balancing, and show their relationship to response time and throughput. We outline the main components of an intelligent, self-reliant file system that aims to optimize striping by taking into account the requirements of the applications, and performs load balancing by judicious file allocation and dynamic redistributions of the data when access patterns change. Our system uses simple but effective heuristics that incur only little overhead. We present performance experiments based on synthetic workloads and real-life traces. Received May 17, 1994 / Accepted June 9, 1997     

Deformation Behaviour of Iron‐Rich Iron‐Aluminium Alloys with Ternary Transition Metal Additions

The hardness and yield stress at room temperature and the brittle‐to‐ductile transition temperature of Fe‐Al alloys with 16 at.% Al, which is in the range of the so‐called K‐state with possible short‐range ordering reactions, and ternary additions of 0.5 and 4 at.% of the transition metals Cr, Mo, Mn, V, Ti and Ni were studied with respect to possible hardening effects of the ternary additions. The addition of Cr, Mo and Mn to the Fe‐Al alloys produce solid‐solution hardening which corresponds to the hardening effect of Al. Only Ti, V and Ni produce extra hardening effects which cannot be related to solid‐solution hardening. This extra hardening is attributed to possible fine NiAl precipitates in the Fe‐Al‐Ni case and to possible enhanced short‐range ordering and/or fine carbide precipitates in the cases of Fe‐Al‐V and Fe‐Al‐Ti.     

Topography simulation of sputtering using an algorithm with second order approximation in space

For the efficient simulation of topography evolution due to, e.g., focused ion beam processes, continuum surface advancement algorithms are commonly used. In this work we present a two-dimensional surface advancement algorithm that uses circular arcs between nodes and allows kinks in the surface. The algorithm is based on the method of characteristics, which yields the motion of the points and the slope of the surface. By the interpolation with circular arcs not only the final result is better represented, but also more accurate simulation is possible after insertion of new points as the surface evolves. Kinks in the surface (shocks) are detected by the generation of loops in the surface string or by a new criterion based on the analysis of infinitesimally separated characteristics. It requires the curvature of the surface, which may readily be determined from the radii of the circular arcs. The proposed algorithm uses a second order approximation in space and therefore requires fewer data points during calculation than first order methods. It is shown to converge with third order as a function of node number. The method is demonstrated by examples of trench formation including the effect of redeposition and of facet formation from a step-like surface.     

Design für Kostentransparenz in Anlageberatungsgespr?chen

Investment advisory services of financial service providers (FSPs) exhibit several characteristics that are detrimental to advisory quality. The interaction of advisor and client is strained by a lack of transparency regarding the advisory process (what activities are performed and why) and the information used therein (what information is used for what purpose and with what effect), as well as regarding the precise costs of the service and the recommended products. In prior research, we suggested that process and information transparency issues may be appropriately addressed with collaborative information technology (IT) artifacts. In this paper, we argue that collaborative, transparent artifacts may also be a premise of enabling cost transparency. To this end, we describe a complete research cycle of designing, implementing, and evaluating a shared cost-transparent IT artifact to support client-advisor interaction in investment advisory encounters. Evaluation results suggest the efficacy of our design in improving the clients?? perceived cost transparency as well as increase their satisfaction and their willingness to pay for the received investment advice. These findings may also challenge the common belief of FSPs that transparent, fee-based advisory services would neither be accepted by clients nor be economically viable. Practical implications of these findings for designing advisory encounters with supportive IT are discussed.     

Reactivity characteristics of nanoscale zerovalent iron--silica composites for trichloroethylene remediation

Spherical silica particles containing nanoscale zerovalent iron were synthesized through an aerosol-assisted process. These particles are effective for groundwater remediation, with the environmentally benign silica particles serving as effective carriers for nanoiron transport. Incorporation of iron into porous sub-micrometer silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their subsurface mobility. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosolized silica particles with functional alkyl moieties, such as ethyl groups on the surface, clearly adsorb solubilized trichloroethylene (TCE) in water. These materials may therefore act as adsorbents which have coupled reactivity characteristics. The nanoscale iron/silica composite particles with controlled surface properties have the potential to be efficiently applied for in situ source depletion and in the design of permeable reactive barriers.     

Phytochemical composition and antioxidant capacity of various botanical parts of the fruits of Prunus × domestica L. from the Lorraine region of Europe

Mirabelle plums represent a famous fruit from the Lorraine region, however little is known about their phytochemical composition. The oil of the fruit contained predominantly oleic acid (59%) and linoleic acid (29%). The total content of phenolic antioxidants in the whole fruits was 5.338 g/kg with 456 mg/kg (9%), 701 mg/kg (13%) and 4159 mg/kg (78%) detected in the peels, flesh and pits respectively. The peels contained solely 3,4-dihydroxybenzoic acid (270 mg/kg) and rutin (186 mg/kg), the flesh exclusively echinoids (723 mg/kg), whereas the pits contained a rich variety of phenolic compounds (4.2 g/kg) dominated by amygdalin (3.8 g/kg), but with significant contributions from vanillin (102 mg/kg), guajacyl-glycerin-coniferyl aldehyde isomers (87 mg/kg), dehydro-diconiferyl aldehyde (52 mg/kg), and vanillin diglucoside (48 mg/kg). Of the major phenolic compounds tested across a range of in vitro assays, rutin was the superior antioxidant.     

TcdB of Clostridioides difficile Mediates RAS-Dependent Necrosis in Epithelial Cells

A Clostridioides difficile infection (CDI) is the most common nosocomial infection worldwide. The main virulence factors of pathogenic C. difficile are TcdA and TcdB, which inhibit small Rho-GTPases. The inhibition of small Rho-GTPases leads to the so-called cytopathic effect, a reorganization of the actin cytoskeleton, an impairment of the colon epithelium barrier function and inflammation. Additionally, TcdB induces a necrotic cell death termed pyknosis in vitro independently from its glucosyltransferases, which are characterized by chromatin condensation and ROS production. To understand the underlying mechanism of this pyknotic effect, we conducted a large-scale phosphoproteomic study. We included the analysis of alterations in the phosphoproteome after treatment with TcdA, which was investigated for the first time. TcdA exhibited no glucosyltransferase-independent necrotic effect and was, thus, a good control to elucidate the underlying mechanism of the glucosyltransferase-independent effect of TcdB. We found RAS to be a central upstream regulator of the glucosyltransferase-independent effect of TcdB. The inhibition of RAS led to a 68% reduction in necrosis. Further analysis revealed apolipoprotein C-III (APOC3) as a possible crucial factor of CDI-induced inflammation in vivo.