Oxidative dehydrogenation of cyclohexene on atomically precise subnanometer Cu4-nPdn (0 ≤ n ≤ 4) tetramer clusters: the effect of cluster composition and support on performance.

The pronounced effects of the composition of four-atom monometallic Cu and Pd and bimetallic CuPd clusters and the support on the catalytic activity and selectivity in the oxidative dehydrogenation of cyclohexene are reported. The ultra-nanocrystalline diamond supported clusters are highly active and dominantly produce benzene; some of the mixed clusters also produce cyclohexadiene, which are all clusters with a much suppressed combustion channel. The also highly active TiO2-supported tetramers solely produce benzene, without any combustion to CO2. The selectivity of the zirconia-supported mixed CuPd clusters and the monometallic Cu cluster is entirely different; though they are less active in comparison to clusters with other supports, these clusters produce significant fractions of cyclohexadiene, with their selectivity towards cyclohexadiene gradually increasing with the increasing number of copper atoms in the cluster, reaching about 50% for Cu3Pd1. The zirconia-supported copper tetramer stands out from among all the other tetramers in this reaction, with a selectivity towards cyclohexadiene of 70%, which far exceeds those of all the other cluster-support combinations. The findings from this study indicate a positive effect of copper on the stability of the mixed tetramers and potential new ways of fine-tuning catalyst performance by controlling the composition of the active site and via cluster-support interactions in complex oxidative reactions under the suppression of the undesired combustion of the feed.

[Basic principles and difficulties relating to rehabilitation in diabetic patients following amputation]. / Základní principy a úskalí rehabilitace u diabetiku po amputaci.

Vascular diseases as a result of diabetes mellitus are the most frequent indication for amputation in the Czech republic. Diabetic patients following amputation, unlike the other amputees, very frequently suffer multiple complications. These are both of general and local nature and pose a limitation to rehabilitation care as well as a prosthesis use. The main goal of therapeutic rehabilitation is the practice of locomotion with a prosthesis (artificial limb) and the patients full return to normal life. A team of closely cooperating specialists is involved. The rehabilitation care of amputees is divided into acute and aftercare. Within preoperative care we try to improve the patients physical and psychological condition. Following surgery we verticalize the patient as soon as possible depending on his/her possibilities and condition, we carry out breathing and vascular gymnastics and prevention of thromboembolic disease and we start the care of the stump. When the stump has been healed and shaped, the patient is provided with an artificial limb. The patients equipped with an artificial limb take a walking course where they learn how to handle the limb as well as walk indoors and outdoors and cope with common terrain unevenness.Key words: amputation - diabetes mellitus - walking with an artificial limb - prosthesis - lower limb prosthetics.

Electrostatic Gating of Monolayer Graphene by Concentrated Aqueous Electrolytes.

Electrostatic gating using electrolytes is a powerful approach for controlling the electronic properties of atomically thin two-dimensional materials such as graphene. However, the role of the ionic type, size, and concentration and the resulting gating efficiency is unclear due to the complex interplay of electrochemical processes and charge doping. Understanding these relationships facilitates the successful design of electrolyte gates and supercapacitors. To that end, we employ in situ Raman microspectroscopy combined with electrostatic gating using various concentrated aqueous electrolytes. We show that while the ionic type and concentration alter the initial doping state of graphene, they have no measurable influence over the rate of the doping of graphene with applied voltage in the high ionic strength limit of 3-15 M. Crucially, unlike for conventional dielectric gates, a large proportion of the applied voltage contributes to the Fermi level shift of graphene in concentrated electrolytes. We provide a practical overview of the doping efficiency for different gating systems.

Comparison of different starting gonadotropin doses (50, 75 and 100 IU daily) for ovulation induction combined with intrauterine insemination.

PURPOSE: To prevent multiple pregnancies the goal of ovulation induction by gonadotropins is to achieve only mono-follicular development. The most important issue is therefore to determine the starting dose. The aim of this study is to compare three different starting doses of follitropin beta to assess the lowest effective dose. METHODS: We evaluated 92 cycles with ovarian stimulation for patients with unexplained infertility, anovulatory disorder or mild male factor. We prospectively divided patients into 50, 75 and 100 IU groups based on patients' response to clomiphene citrate treatment. RESULTS: We performed 87 intrauterine inseminations (95 % of cycles with ovulation induction). Five cycles were cancelled. We achieved 15 pregnancies; total pregnancy rate was 18 %. Pregnancy rate was 22, 10 and 28 % in 50, 75 and 100 IU follitropin beta groups. The average number of follicles was 2.0 ± 0.8, 2.2 ± 1.1 and 2.5 ± 1.8 (ns), total dose of gonadotropins (IU) 483 ± 192, 600 ± 151 and 830 ± 268 (p < 0.001), respectively. We observed one case of twins in 75 and 100 IU treatment group, as well (25 % risk). CONCLUSIONS: This study suggests that based on the dose which was chosen according to clomiphene citrate response, all treatment regimes were effective for ovulation induction. 50 IU of follitropin beta daily is the appropriate starting dose to support ovulation for clomiphene citrate-sensitive women. The disadvantage may be an increased risk of cycle cancellation due to low ovarian response. Daily doses 75 or 100 IU of rFSH increase total consumption of gonadotropins.

Localized Spectroelectrochemical Identification of Basal Plane and Defect-Related Charge-Transfer Processes in Graphene.

It is well-known that structural defects play a decisive role in electrochemical behavior of atomically thin materials, where all the defects are directly accessible by the electrolyte. However, the vast majority of experimental techniques do not allow disentanglement of the processes at the edges/defects from those at the intact basal plane. Therefore, to address this issue, we introduce a localized spectroelectrochemical method featuring a microdroplet electrochemical cell with simultaneous Raman spectroscopy monitoring. The electrochemical and spectral responses of the basal planes of monolayer graphene samples with varying levels of disorder were compared. Two contributions, stemming from the intact and defective areas on the surface, respectively, were discovered both in the Raman G band shifts and cyclic voltammetry using the hexaammineruthenium complex. Consequently, two independent electron transfer processes of slower and faster rates coexist in one sample, but they are restricted to the defect-free and defect-rich areas, respectively.