Risperidone versus haloperidol: I. Meta-analysis of efficacy and safety

Stepwise solution syntheses are described of the homo-oligomers Z-(Thr)n-NHCH3 (n=1-4, I1-4), Z-?[Gal(Ac)4beta]Thr?n-NHCH3(n=1-5, II1-5) and Z-[(Galbeta)Thr]n-NHCH3 (n=1-5, III1-5). Members of the III1-5 series were obtained by de-acetylation of the corresponding oligomers of the II1-5 series. The conformational preferences of the terminally protected homo-peptides of the three series were investigated by FT-IR absorption spectroscopy both in the solid state and in CDCl3 solution, at various concentrations. Proton NMR measurements in CDCl3 and in DMSO-d6 were also carried out and the effect of temperature variation on the chemical shifts of amide protons was determined in DMSO-d6 (range 298-335 K) and in CDCl3 (range 298-320K). CD spectra were recorded in water and in TFE. Solubility problems prevented measurements in CDCl3 solution for Z-(Thr)4-NHCH3 and for the entire III1-5 series. The existence of unordered structures in the carbohydrate-free oligomers and of more or less extended, organized structures in the glycosylated derivatives is indicated by the NMR and IR measurements. The sugar moieties apparently show a structure-inducing effect on the peptide chain.     

Fluorescence quenching by chlorophyll cations in photosystem II

Although fluorescence is widely used to study photosynthetic systems, the mechanisms that affect the fluorescence in photosystem II (PSII) are not completely understood. The aim of this study is to define the low-temperature steady-state fluorescence quenching of redox-active centers that function on the electron donor side of PSII. The redox states of the electron donors and acceptors were systematically varied by using a combination of pretreatments and illumination to produce and trap, at low temperature, a specific charge-separated state. Electron paramagnetic resonance spectroscopy and fluorescence intensity measurements were carried out on the same samples to obtain a correlation between the redox state and the fluorescence. It was found that illumination of PSII at temperatures between 85 and 260 K induced a fluorescence quenching state in two phases. At 85 K, where the fast phase was most prominent, only one electron-transfer pathway is active on the donor side of PSII. This pathway involves electron donation to the primary electron donor in PSII, P680, from cytochrome b559 and a redox-active chlorophyll molecule, ChlZ. Oxidized ChlZ was found to be a potent quencher of chlorophyll fluorescence with 15% of oxidized ChlZ sufficient to quench 70% of the fluorescence intensity. This implies that neighboring PSII reaction centers are energetically connected, allowing oxidized ChlZ in a few centers to quench most of the fluorescence. The presence of a well-defined quencher in PSII may make it possible to study the connectivity between antenna systems in different sample preparations. The other redox-active components on the donor side of PSII studied were the O2-evolving complex, the redox-active tyrosines (YZ and YD), and cytochrome b559. No significant changes in fluorescence intensity could be attributed to changes in the redox state of these components. The fast phase of fluorescence quenching is attributed to the rapid photooxidation of ChlZ, and the slow phase is attributed to multiple turnovers providing for further oxidation of ChlZ and irreversible photoinhibition. Significant photoinhibition only occurred at Chl concentrations below 0.7 mg/mL and above 150 K. The reversible oxidation of ChlZ in intact systems may function as a photoprotection mechanism under high-light conditions and account for a portion of the nonphotochemical fluorescence quenching.     

Osteomyelitis of the foot: relative importance of primary and secondary MR imaging signs

STUDY OBJECTIVES: Dyspnea is most commonly assessed by questioning patients about their subjective perception of shortness of breath during physical exertion. Although speech production is altered by pulmonary disease, it has not been included in current dyspnea assessment tools. A questionnaire was developed to address reports of dyspnea during (1) physical activity, (2) speech activity, and (3) simultaneous speech and physical activity. DESIGN: An equal number of self- and experimenter-administered 30-item questionnaires was given to 203 patients with restrictive and obstructive pulmonary diseases. Their responses were analyzed statistically. RESULTS: The questionnaire had high internal consistency for individual items within each of the three sections. The sections were highly correlated but provided separate and distinct information. Factors extracted from each section were related to severity of dyspnea. Pairwise t tests demonstrated highly significant differences in subject responses to the three sections. The least dyspnea was experienced during speech activities, more during physical activities, and the most when speech and physical activities were combined. CONCLUSIONS: The questionnaire proved to be a quickly administered tool for providing information about the effect of dyspnea on activities of daily living. Because of the emphasis on dyspnea during speech production, it may be particularly useful for assessing patients who rely extensively on speaking ability for their livelihood.     

Magnetic resonance imaging of ankle ligament injuries correlated with time

Ankle sprain is one of the most commonly treated injuries of the lower extremity. The treatment depends on the severity of the injury and the time at which it occurred. The physician must rely on the history as related by the patient to determine the age of the injury. Magnetic resonance imaging has been proven to help determine the severity of the injury but has not been used to determine the age of the injury. The present study was conducted to identify the typical findings of acute and chronic ankle sprains as a means of dating an ankle sprain based on its appearance on magnetic resonance imaging.     

Patterns of GFAP-immunoreactivity parallel the tonotopic axis in the developing dorsal cochlear nucleus

The gain of the H reflex attenuates during passive stepping and pedalling movements of the leg. We hypothesized that the kinematics of the movement indirectly reflect the receptor origin of this attenuation. In the first experiment, H reflexes were evoked in soleus at 26 points in the cycle of slow, passive pedalling movement of the leg and at 13 points with the leg static (the ankle was always immobilized). Maximum inhibition occurred as the leg moved through its most flexed position (P < 0.05). Inhibition observed in the static leg was also strongest at this position (P < 0.05). The increase in inhibition was gradual during flexion movement, with rapid reversal of this increase during extension. In the second experiment, the length of stretch of the vasti muscles was modelled. Variable pedal crank lengths and revolutions per minute (rpm) altered leg joint displacements and angular velocities. Equivalent rates of stretch of the vasti, achieved through different combinations of joint displacements and velocities, elicited equivalent attenuations of mean reflex magnitudes in the flexed leg. Reflex gain exponentially related to rate of stretch (R2 = 0.98 P < 0.01). The results imply that gain attenuation of this spinal sensorimotor path arises from spindle discharge in heteronymous extensor muscles of knee and/or hip, concomitant with movement.     

The robot as an intelligent interactive machine

The growth of interconnections between mechanical and electrical engineering and computer science, characterized by the term mechatronics, is most obvious for the field of robotics. These interconnections allow an ‘intelligent’ behaviour of a machine, depending on its ability to pick up information about its environment, and to process it in such a way that it reacts according to the situation. In our working environment most often an interaction with a human operator will be necessary or desirable. Subsequently, three robotic projects of the ETH will be presented where this man/machine interaction is, or will be, realized under various intentions and constraints: a table tennis playing robot, a mobile, sensor-supported manipulator, and a cooperating robot.     

Mechatronics for the design of human-oriented machines

One of the topics of mechatronics is the design of "intelligent" machines, thus making them different from previous ones and allowing more sophisticated cooperation between humans and machines. Such machines are expected to emulate human skills and to communicate and interact with their human users on an appropriate level. The requirements for such human-oriented machines and the implications on their design will be discussed here. A number of examples from actual Swiss Federal Institute of Technology (ETH) research, ranging from nanomanipulation tasks and medical devices to a mobile service robot, demonstrate the application of the concept.     

Catching up or falling behind? Promising changes and persistent patterns across cohorts of economics PhDs in German-speaking countries from 1991 to 2008

We investigate economics PhDs minted at German, Austrian, and Swiss universities from 1991 to 2008. We find that cohort sizes increased overall, and the share of PhDs who publish in a peer-reviewed journal within 6 years after graduation increased from 18% in 1991 to 46% in 2008. Publishing rates are heterogeneous across departments. Younger cohorts publish slightly more compared to older cohorts, but these publications are not significantly better in terms of quality. Publication productivity is highly skewed within and between departments. A key difference between PhDs of the German-speaking area and North America lies in their patterns of collaboration.     

Resistivity Studies on Different Variants of κ-(BEDT-TTF)2Cu[N(CN)2]Br: Evidence for Disorder and /or Defect-Induced Inelastic Scattering Contributions

Comparative resistivity measurements have been performed on differently prepared κ-(ET)₂Cu[N(CN)₂]Br single crystals. While the T_c values and their shifts under hydrostatic pressure are found to be sample independent, the resistivity profiles, especially around the resistivity hump at 90 K and the low-temperature ρ ∝ T² behavior, show striking sample-to-sample variations. In the absence of significant differences in the crystals’ structural parameters and chemical compositions, as proved by high-resolution X-ray and electron-probe-microanalysis studies, these results indicate that real structure phenomena, i.e. disorder and/or defects, strongly affect the inelastic scattering in these molecular conductors.