Highly Active W2C-Based Composites for the HER in Alkaline Solution: the Role of Surface Oxide Species.

The hydrogen evolution reaction (HER) is a crucial electrochemical process for the proposed hydrogen economy since it has the potential to provide pure hydrogen for fuel cells. Nowadays, hydrogen electroproduction is considerably expensive, so promoting the development of new non-noble catalysts for the cathode of alkaline electrolyzers appears as a suitable way to reduce the costs of this technology. In this sense, a series of tungsten-based carbide materials have been synthesized by the urea-glass route as candidates to improve the HER in alkaline media. Moreover, two different pyridinium-based ionic liquids were employed to modify the surface of the carbide grains and control the amount and nature of their surface species. The main results indicate that the catalyst surface composition is modified in the hybrid materials, which are then distinguished by the appearance of tungsten suboxide structures. This implies the action of ionic liquids as reducing agents. Consequently, differential electrochemical mass spectrometry (DEMS) is used to precisely determine the onset potentials and rate-determining steps (RDS) for the HER in alkaline media. Remarkably, the modified surfaces show high catalytic performance (overpotentials between 45 and 60 mV) and RDS changes from Heyrovsky-Volmer to Heyrovsky as the surface oxide structures get reduced. H2O molecule reduction is then faster at tungsten suboxide, which allows the formation of the adsorbed hydrogen at the surface, boosting the catalytic activity and the kinetics of the alkaline HER.

Multichannel laser diode to polymer waveguide array coupling with a double-aspheric lens.

An optical system for multichannel coupling of laser arrays to polymer waveguide array probes with a single biconvex lens is developed. The developed cylindrical module with 13 mm and 20 mm in diameter and length, respectively, enables coupling of eight individual optical channels using an aspheric lens. Specific coupling with crosstalk below -13d B for each channel and quasi-uniform coupling over all channels is achieved for a waveguide array with 100 µm lateral facet pitch at the incoupling site. The polymer waveguide technology allows for tapering of the lateral waveguide pitch to 25 µm toward the tip of the flexible waveguide array. SU-8 and PMMA are used as the waveguide core and cladding, respectively. The optical coupling module is designed as a prototype for preclinical evaluation of optical neural stimulators.

Flexible auditory training, psychophysics, and enrichment of common marmosets with an automated, touchscreen-based system.

Devising new and more efficient protocols to analyze the phenotypes of non-human primates, as well as their complex nervous systems, is rapidly becoming of paramount importance. This is because with genome-editing techniques, recently adopted to non-human primates, new animal models for fundamental and translational research have been established. One aspect in particular, namely cognitive hearing, has been difficult to assess compared to visual cognition. To address this, we devised autonomous, standardized, and unsupervised training and testing of auditory capabilities of common marmosets with a cage-based standalone, wireless system. All marmosets tested voluntarily operated the device on a daily basis and went from naïve to experienced at their own pace and with ease. Through a series of experiments, here we show, that animals autonomously learn to associate sounds with images; to flexibly discriminate sounds, and to detect sounds of varying loudness. The developed platform and training principles combine in-cage training of common marmosets for cognitive and psychoacoustic assessment with an enriched environment that does not rely on dietary restriction or social separation, in compliance with the 3Rs principle.

Immune phenotyping study revealing caveats regarding a switch from fingolimod to cladribine.

BACKGROUND: Recent data support a key role of B cells in the pathogenesis of multiple sclerosis. Due to the pronounced effect of cladribine on memory B cells, we initiated an immune phenotyping study, which included monitoring of memory B cells of patients newly assigned to this treatment option. A patient with ongoing disease activity in the first year of cladribine after a long-standing fingolimod treatment caught our attention. OBJECTIVE: To report about differences in the immune phenotype of the case compared to patients without disease activity and to discuss possible causes for the deviations as caveats regarding treatment sequelae. METHODS: Clinical data and immune phenotyping data collected at baseline (before treatment) and after three, six and ten/twelve months after cladribine initiation were compared between our case and six patients with a stable disease course (controls). RESULTS: Both, the case and controls showed similar reductions of memory B cells in response to cladribine. The case however, showed an accelerated repopulation dynamic of naïve B cells with an almost 3-fold hyperrepopulation compared to baseline levels, and lower pre-treatment levels of CD4+ and CD8+ T cells and memory B cells compared to controls. CONCLUSION: We propose a prolonged pre-treatment with fingolimod as possible cause for the lack of response to cladribine. Autoreactive cells sequestrated within lymph nodes may have evaded cladribine depletion on top of a delay of recirculating regulatory T cells. In addition, we want to raise awareness of the importance of monitoring T and B cells for bridging the current lack of evidence regarding sequencing therapies in the real life setting.

Validation of the ultrasonographic assessment of the femoral trochlea epiphyseal cartilage in foals at osteochondrosis predilected sites with magnetic resonance imaging and histology.

BACKGROUND: Noninvasive imaging tools are needed to screen foal femoropatellar joints to detect subclinical osteochondrosis lesions due to focal failure of endochondral ossification to enhance early management to optimise intrinsic healing events. Recently investigations employing 3T susceptibility-weighted magnetic resonance imaging (3T SWI MRI) and CT have demonstrated their capacity for early osteochondrosis diagnosis, but these technologies are not practical for field screening. We postulate that ultrasonography is a valuable field tool for the detection of subclinical osteochondrosis lesions. OBJECTIVES: The goals were to 1) describe the ultrasonographic features of the femoral trochlea of healthy and osteochondrosis-predisposed neonatal foals, 2) validate the capacity of ultrasound to assess cartilage canal vascular archictecture and the ossification front and 3) evaluate field feasibility in a pilot study. STUDY DESIGN: Experimental study. METHODS: Ultrasonographic evaluation of osteochondrosis predisposed (n = 10) and control (n = 6) femoral trochleas was performed ex vivo and compared with site-matched histological sections and 3T SWI MRI. The articular and epiphyseal cartilage thickness, ossification front indentation and cartilage canal vascular archictecture were assessed at each ROI. Femoral trochleae of foals (n = 3) aged ≈ 1, 3 and 6 months were also evaluated with ultrasonography in field. RESULTS: Ultrasonographic measurements strongly correlated with the histological measurements. There was no difference in the cartilage thickness or ossification front indentation between control and osteochondrosis-predisposed specimens. The cartilage canal vascular archictecture on ultrasonograms corresponded with the vessel pattern observed on site matched histology and 3T SWI MRI. MAIN LIMITATIONS: The number of specimens for study was limited and no early osteochondrosis lesions were present within the predilected group, but a field study is now underway. CONCLUSION: Ultrasonographic examination of the femoral trochlea permitted accurate evaluation of cartilage thickness, cartilage canal vascular archictecture and ossification front indentation in young foals and is a promising, practical tool for screening subclinical osteochondrosis and monitoring and managing lesions at important clinical sites.

3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom.

In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX™ container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated treatment concepts in adaptive radiotherapy.

Entrapment and traumatic neuropathies of the elbow and hand: An imaging approach.

Ultrasound and magnetic resonance imaging currently offer a detailed analysis of the peripheral nerves. Compressive and traumatic nerve injuries are the two main indications for imaging investigation of nerves with several publications describing the indications, technique and diagnostic capabilities of imaging signs. Investigation of entrapment neuropathies has three main goals, which are to confirm neuronal distress, search for the cause of nerve compression and exclude a differential diagnosis on the entire nerve. For traumatic nerve injuries, imaging, predominantly ultrasound, occasionally provides essential information for management including the type of nerve lesion, its exact site and local extension.

Relating structure and function of inner hair cell ribbon synapses.

In the mammalian cochlea, sound is encoded at synapses between inner hair cells (IHCs) and type I spiral ganglion neurons (SGNs). Each SGN receives input from a single IHC ribbon-type active zone (AZ) and yet SGNs indefatigably spike up to hundreds of Hz to encode acoustic stimuli with submillisecond precision. Accumulating evidence indicates a highly specialized molecular composition and structure of the presynapse, adapted to suit these high functional demands. However, we are only beginning to understand key features such as stimulus-secretion coupling, exocytosis mechanisms, exo-endocytosis coupling, modes of endocytosis and vesicle reformation, as well as replenishment of the readily releasable pool. Relating structure and function has become an important avenue in addressing these points and has been applied to normal and genetically manipulated hair cell synapses. Here, we review some of the exciting new insights gained from recent studies of the molecular anatomy and physiology of IHC ribbon synapses.

Transforaminal versus intra-articular facet corticosteroid injections for the treatment of cervical radiculopathy: a randomized, double-blind, controlled study.

BACKGROUND AND PURPOSE: Transforaminal corticosteroid injections can be performed in the management of cervical radiculopathy but carry the risk of catastrophic complications. This study compares the efficacy of transforaminal and facet corticosteroid injections at 4 weeks' follow-up. MATERIALS AND METHODS: We randomly assigned 56 subjects to receive CT-guided transforaminal (15 men, 13 women; mean age, 52 years; range, 28-72 years) or facet (8 men, 20 women; mean, 44 years; range, 26-60 years) injections. The primary outcome was pain severity rated on a Visual Analog Scale (0-100). Secondary outcomes were the Neck Disability Index and the Medication Quantitative Scale. RESULTS: In the intention-to-treat and as-treated analyses, for a mean baseline score, facet injections demonstrated a significant pain score reduction of 45.3% (95% CI, 21.4-69.2) and 37.0% (95% CI, 9.2-64.7), while transforaminal injections showed a nonsignificant pain score reduction of 9.8% (95% CI, +11.5-31.2) and 17.8% (95% CI, +6.6-42.2). While facet injections demonstrated an improvement in the Neck Disability Index score of 24.3% (95% CI, +2.9-51.5) and 20.7% (95% CI, +6.2-47.6) as opposed to transforaminal injections of 9.6% (95% CI, +15.2-34.4) and 12.8% (95% CI, +11.2-36.7), the results were not statistically significant. Noninferiority of facet to transforaminal injections was demonstrated for baseline pain scores of ≤60, while noninferiority analysis was inconclusive for baseline pain scores of ≥80 and for the Neck Disability Index. Neither intervention showed a significant medication-intake score reduction with time. CONCLUSIONS: Facet injections are effective for the treatment of cervical radiculopathy and represent a valid and safer alternative to transforaminal injections.

Current and future imaging of the peripheral nervous system.

Peripheral nervous system (PNS) imaging is usually carried out by ultrasound and MRI. Thanks to its wide availability and excellent spatial resolution, ultrasound is a mature investigation with clearly established indications, particularly in entrapment syndromes and tumors. MRI is generally a second-line examination, which provides decisive additional information thanks to its excellent contrast resolution and its multiplanar abilities. This review describes the current methods for imaging the PNS, concentrating on acquisition techniques, normal results and basic pathological semiology. Ongoing and future developments are described in order to underline the forthcoming changes in this very dynamic field of musculoskeletal radiology.

The response of soil organism communities to the application of the insecticide lindane in terrestrial model ecosystems.

The EU plant protection regulation 1107/2009/EC defines the requirements for active ingredients to be approved, specifically including the assessment of effects on biodiversity and ecosystems. According to that, semi-field methods are expected to be more important in the near future. Therefore, a higher-tier experiment suitable to assess the risk for soil organisms was conducted to further develop the TME (terrestrial model ecosystems) methodology in a dose-response design with the persistent insecticidal model compound lindane (gamma-HCH). The effects of lindane on soil communities such as collembolans, oribatid mites, nematodes, soil fungi and plant biomass were determined in 42 TME. Intact TME-soil cores (diameter 300 mm, height 400 mm) from undisturbed grassland were stored outdoor under natural climatic conditions. Lindane was applied in five concentrations between 0.032 mg active ingredients (ai)/kg dry soil and 3.2 mg ai/kg dry weight soil, six-fold replicated each. Twelve TME served as untreated controls. Abundance and community structures of oribatids, collembolans, enchytraeids, nematodes and fungi were recorded. Oribatid mites' community responded 3 months after treatment, although they were not significantly affected by the overall treatment regimen. Collembolans in total and species-specific abundance as well as the community endpoints (principal response curves, diversity measures) were adversely affected by moderate dosages of lindane. Effects were transient between 3 and 5 months after treatment with a recovery within 1 year. No significant effects could be detected for enchytraeids, nematodes and fungi. The study design and the obtained results allow for calculations of no observed effect concentrations below the highest treatment level for populations and for soil communities as defined entities, as well as effective concentrations. The paper discusses the limits of effect detection in the light of achievable coefficients of variation and by means of minimum detectable differences. Outdoor TME are useful to analyze and assess functional and structural endpoints in soil organisms' communities and their possible recovery after pesticide treatment within 1 year.

3T tractography of the median nerve: optimisation of acquisition parameters and normative diffusion values.

PURPOSE: To define the optimal acquisition parameters for diffusion tensor imaging of the median nerve at the wrist and to measure the diffusion values. PATIENTS AND METHODS: The wrists of 14 healthy volunteers were explored using 3T MRI with a dedicated wrist coil. Each examination consisted of six sequences, varying the number of directions (15-20-30) and the b values (500-800-1000-2000s/mm(2)). The tractography images were evaluated by two radiologists using a qualitative scale with six levels. The diffusion and anisotropy coefficients (ADC and FA) were measured and the values compared with the data in the literature. RESULTS: Median nerve tractography was successfully achieved in all sequences. The 20 direction sequence with b=1000s/mm(2) seemed to provide the best results for a reasonable acquisition time (5'38″). The diffusion values showed large interindividual variations. CONCLUSION: Optimisation of acquisitions parameters is important in peripheral nerve tractography, and may facilitate a routine use of the technique. The images obtained are easy to analyse but the diffusivity and anisotropy coefficients are too variable, however, to be used in practice.

The growing family of photoactive yellow proteins and their presumed functional roles.

For several years following the discovery and characterization of the first PYP, from Halorhodospira halophila, it was thought that this photoactive protein was quite unique, notwithstanding the isolation of two additional examples in rapid succession. Mainly because of genomic and metagenomic analyses, we have now learned that more than 140 PYP genes occur in a wide variety of bacteria and metabolic niches although the protein has not been isolated in most cases. The amino acid sequences and physical properties permit their organization into at least seven groups that are also likely to be functionally distinct. Based upon action spectra and the wavelength of maximum absorbance, it was speculated nearly 20 years ago but never proven that Hr. halophila PYP was involved in phototaxis. Nevertheless, in only one instance has the functional role and interaction partner for a PYP been experimentally proven, in Rs. centenum Ppr. Genetic context is one of several types of evidence indicating that PYP is potentially involved in a number of diverse functional roles. The interaction with other sensors to modulate their activity stands out as the single most prominent role for PYP. In this review, we have attempted to summarize the evidence for the functional roles and interaction partners for some 26 of the 35 named species of PYP, which should be considered the basis for further focused molecular and biochemical research.

[Super-resolution optical microscopy of the organ of Corti. Investigations on the fine structure of the inner hair cell afferent synapse by the 4Pi and STED techniques]. / Höchstauflösende optische Mikroskopie am Corti-Organ. Feinstrukturaufklärung an der afferenten Synapse innerer Haarzellen mittels 4Pi- und STED-Technik.

BACKGROUND: Inner hair cells encode sound into action potentials in the auditory nerve. Spiral ganglion neurons form the afferent innervation of inner hair cells via the hair cell synapse. The structure and function of this ribbon-type synapse is considered to have a major impact on the sound encoding process itself. In this study we have used conventional confocal microscopy as well as super-resolution techniques to investigate the synaptic organization in the inner hair cells of mice. MATERIAL AND METHODS: Functionally relevant proteins of the afferent inner hair cell synapse were selectively marked using immunohistochemical methods and investigated with conventional confocal and super-resolution 4Pi- and stimulated emission depletion (STED) techniques. RESULTS: Synapse and innervation density was mapped over the entire tonotopic axis. We found inner hair cells in the region of best hearing to have about twice the number of afferent fibres compared to the apex or base of the cochlea. For the first time 4Pi and STED microscopic techniques were employed to resolve the fine structure of these synapses beyond the resolution of conventional light microscopy. With 4Pi a resolution of approximately 100 nm in the z-axis direction is feasible. In practice STED delivers an effective resolution between 150 and 30 nm, depending on the power of the lasers employed. Synapses at different tonotopic positions of the cochlea exhibit no relevant structural differences at this level of resolution. The 4Pi and STED microscopic techniques are capable of showing the structure of afferent synapses in the organ of Corti with unsurpassed resolution. These images contribute to our understanding of sound-encoding mechanisms in the inner ear.

Neural circuit development in the mammalian cochlea.

The organ of Corti, the sensory epithelium of the mammalian auditory system, uses afferent and efferent synapses for encoding auditory signals and top-down modulation of cochlear function. During development, the final precisely ordered sensorineural circuit is established following excessive formation of afferent and efferent synapses and subsequent refinement. Here, we review the development of innervation of the mouse organ of Corti and its regulation.

Pitfalls in osteoarticular imaging: how to distinguish bone infection from tumour?

In this article examining pitfalls in osteoarticular imaging we examine the differential diagnosis of osteomyelitis from bone tumours. We describe the different features which differentiate these two types of disease in radiology and CT and MRI scanning.

Ulnar subluxation of the median nerve following carpal tunnel release: a case report.

Complications of carpal tunnel release, while infrequent, include incomplete release resulting in persistent symptoms or recurrence due to postoperative scarring, as well as iatrogenic damage to nerves and vessels. We present the case of a patient who underwent carpal tunnel release with resolution of symptoms in the immediate postoperative period. At one and a half years post release he started to experience numbness and tingling in a median nerve distribution triggered by repetitive ulnar to radial deviation of the wrist, with no symptoms at rest. Dynamic ultrasound showed a subluxation of the median nerve from one side of the palmaris longus tendon to the other. The patient's symptoms were triggered as the median nerve squeezed in between the palmaris longus and flexor digitorum superficialis tendons.

[Pain management in oncology]. / Traitement de la douleur en oncologie.

Several interventional radiology procedures are available for the management of cancer pain. In this article, we will briefly review the different procedures and their value in the setting of cancer pain management under two main categories: indirect action (regional anesthesia from neurolysis) and direct action on the tumor. Percutaneous ablation of bone tumors: alcohol, laser, radiofrequency, microwaves, ultrasound, and cryoablation. Several indications have previously been validated, including thermal ablation of bone metastases with results superior to conventional therapies. Additional applications should be validated over the next few years.

Can injection CT scan assess the residual femoral head vascularity after acute neck fracture?

INTRODUCTION: Femoral neck fracture jeopardizes the vital prognosis of the elderly subject and the functional prognosis of the young subject. The vascular consequence is important, with the risk of osteonecrosis of the femoral head. In young patients, predicting the risk of necrosis at the acute stage seems warranted so as to optimize the choice of therapy. CT with injection could be useful to study the residual bone vascularity after an acute fracture of the femoral neck. HYPOTHESIS: The CT scan with injection can diagnose ischemia of the femoral head after neck fracture by demonstrating hypoperfusion and thus estimating the risk for osteonecrosis. PATIENTS AND METHOD: A CT scan with injection was performed prospectively in 20 adult patients who had given informed consent after verification of the inclusion and exclusion criteria. Ten presented femoral neck fracture and 10 a pertrochanteric fracture, the latter making up the control group. The second control group was the healthy side of patients presenting a femoral neck fracture. The images were analyzed after delineating a region of interest as a volume at the center of the femoral head. The results were analyzed after modeling based on the physical principle of diffusion. RESULTS: No differences were found between the "healthy hip," "fractured hip," "femoral neck fracture," and "trochanteric region fracture" groups. The only statistically significant correlation was found between the "fractured hip" and "healthy hip" of the same patient independently of the type of fracture. DISCUSSION: The results do not confirm the working hypothesis. This study was mainly limited by the small number of patients included, but this did not substantially effect the study's conclusions. According to the results, it seems that this study provided a CT evaluation of bone mineral density. At the end of the study, it seems that CT with injection is not well adapted in assessing residual femoral head vascularity or estimating the risk of progression towards avascular necrosis. According to the literature, only dynamic MRI with injection seems to be effective in this assessment and estimation. LEVEL OF EVIDENCE: Level III prospective comparative diagnostic.