Perovskite oxides (ABO3) are a largely unexplored class of materials in solar fuel applications. In this paper we examine the use of nonstoichiometric perovskite-type oxides in a two-step, ...solar-thermochemical water or carbon dioxide splitting cycle. We find that O2 begins to evolve during thermal reduction from a Sr- and Mn-doped LaAlO3 fully 300°C lower than that of CeO2, and that these compounds will split both H2O and CO2. The yield of H2 and CO is significantly greater than CeO2, a benchmark material in solar fuels research, at a thermal reduction temperature 150°C below that commonly reported for CeO2. In addition, the perovskite redox kinetics compare favorably to CeO2, which is known for its rapid reaction rates. We also find that an Fe- doped CaTiO3 is redox active and will split H2O, though the performance of this material is similar to that of CeO2. Finally, we introduce an experimental protocol that combines an ideal stagnation-flow reactor with detailed numerical modeling to effectively deconvolve intrinsic material behavior from interference induced by physical processes occurring inside the flow reactor. This method utilizes rate information contained within the entire time domain of the oxidation reaction, and assigns rate- governing processes to the material within the context of solid-state kinetic theory.
Oral steroids can interrupt bouts of cluster headache (CH) attacks, but recurrence is frequent and may lead to steroid-dependency. Suboccipital steroid injection may be an effective 'single shot' ...alternative, but no placebo-controlled trial is available. The aim of our study was to assess in a double-blind placebo-controlled trial the preventative effect on CH attacks of an ipsilateral steroid injection in the region of the greater occipital nerve. Sixteen episodic (ECH) and seven chronic (CCH) CH outpatients were included. ECH patients were in a new bout since no more than 1 week. After a one-week run-in period, patients were allocated by randomization to the placebo or verum arms and received on the side of attacks a suboccipital injection of a mixture of long- and rapid-acting betamethasone (n=13; Verum-group) or physiological saline (n=10; Plac-group). Acute treatment was allowed at any time, additional preventative therapy if attacks persisted after 1 week. Three investigators performed the injections, while four others, blinded to group allocation, followed the patients. Follow-up visits were after 1 and 4 weeks, whereafter patients were followed routinely. Eleven Verum-group patients (3 CCH) (85%) became attack-free in the first week after the injection compared to none in the Plac-group (P=0.0001). Among them eight remained attack-free for 4 weeks (P=0.0026). Remission lasted between 4 and 26 months in five patients. A single suboccipital steroid injection completely suppresses attacks in more than 80% of CH patients. This effect is maintained for at least 4 weeks in the majority of them.
Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20–35 Hz) assumed to be ...generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in six successive blocks of 100 averaged pattern reversal (PR)-VEPs in healthy volunteers and interictally in migraine with (MA) or without aura patients. Amplitude of the two early GBO components in the first PR-VEP block was significantly increased in MA patients. There was a significant habituation deficit of the late GBO peaks in migraineurs. The increased amplitude of early GBOs could be related to the increased interictal visual discomfort reported by patients. We hypothesize that the hypo-functioning serotonergic pathways may cause, in line with the thalamocortical dysrhythmia theory, a functional disconnection of the thalamus leading to decreased intracortical lateral inhibition, which can induce dishabituation.
The pathophysiology of migraine is far from being understood. Electrophysiological methods are useful to investigate peripheral and central mechanisms underlying this disorder. The purpose of this ...review is to highlight the results of electrophysiological studies published during the last year and to examine their added value to our previous knowledge.
Studies by visual and auditory evoked potentials and event-related responses suggested that lack of habituation is the principal interictal abnormality of sensory processing in migraineurs. Recently confirmed for somatosensory and laser-evoked cortical potentials and for brainstem responses, it is also responsible for the increased intensity dependence of auditory evoked potentials. This abnormality is possibly caused by a reduced cortical preactivation level due to hypofunctioning subcortico-cortical aminergic pathways. Although studies of cortical excitability by transcranial magnetic stimulation have yielded conflicting results, results obtained using habituation of pattern-reversal visual evoked potentials to explore cortical excitability changes induced by repetitive transcranial magnetic stimulation strongly favour the hypothesis that migraine is characterized by a decreased level of preactivation excitability. With regard to pain mechanisms in migraine, electrophysiological studies of trigeminal pathways using nociceptive blink and corneal reflexes have confirmed that sensitization of central trigeminal nociceptors occurs during the attack, and may even persist interictally.
Scientific publications over the last year confirmed that electrophysiological methods are particularly suited to unravelling some of the pathophysiological mechanisms of migraine. To improve their future contribution, they need to be better standardized and to be correlated with behavioural, metabolic and genetic studies.
Migraineurs are characterized interictally by lack of habituation, or even potentiation, of cortical evoked potentials during repetitive stimulation and by a strong intensity dependence of auditory ...evoked potentials (IDAP). To determine whether these two features of sensory processing are interrelated, we have studied them simultaneously on the same recordings of auditory evoked potentials (AEPs). AEPs were obtained at four different stimulation intensities in 14 patients suffering from migraine without aura (MO) and 14 healthy volunteers (HV). For each intensity, 120 trials were averaged off‐line globally and over four sequential blocks of 30 trials. IDAP was expressed by the amplitude/stimulus intensity function (ASF slope) for global and block averages. Habituation was calculated as the percentage amplitude variation between the first and fourth blocks for each stimulus intensity. The IDAP slope for global averages was higher in MO (1.05 ± 0.27 µV/10 dB) than in HV (0.64 ± 0.45 µV/10 dB) (P = 0.008), but IDAP slopes for block averages were greater in MO only at the fourth block (P = 0.048). First block amplitudes tended to be lower in MO, except at 80 dB. There was a potentiation of AEP amplitudes at every stimulus intensity in MO, contrasting with habituation in HV. IDAP slopes were negatively correlated with mean habituation percentages in pooled data from patients and controls (r = –0.610; P = 0.0006). This study confirms that IDAP is higher in migraineurs than in healthy controls. It also shows that the AEP habituation is replaced by potentiation at all stimulus intensities. The negative correlation found between IDAP and habituation suggests that the latter is able to have a strong influence on the former and perhaps even lead to it. In migraine, the habituation deficit amplifies the IDAP and may thus be the causal functional abnormality. We propose that it is due to a decreased pre‐activation level of sensory cortices, a hypothesis also supported in this study by the lower amplitude of first AEP blocks in patients.
Background
Cutaneous melanoma incidence is increasing worldwide, especially for in situ and thin (<1 mm) lesions, while thick (≥1 mm) lesions have been generally stable in many studies; although ...epidemiological data on melanoma is readily available, population‐based studies, especially on mountain regions, are rare.
Objective
The aim of this study was to analyse cutaneous melanoma incidence and Breslow tumour thickness in the central Alpine mountain region of South Tyrol, northern Italy.
Methods
All newly diagnosed cutaneous in situ and invasive melanomas in the resident population from 1998 to 2012 were taken from the Pathology Unit, Bolzano Hospital and South Tyrol Cancer Registry. Incidence and Breslow tumour thickness were analyzed. Statistical analyses included Mann–Whitney and Kruskal–Wallis tests.
Results
A total of 784 in situ melanomas and 1663 invasive melanomas were collected. In situ melanomas showed the highest increase: European age‐standardized incidence rose from 2.44 per 100 000 inhabitants in 1998–2002 to 16.01 in 2008–2012. Invasive melanoma incidence increased from 12.69 in 1998–2002, to 22.88 in 2008–2012. The incidence rise was observed in thin melanomas (from 8.39 to 16.18) and in thick melanomas (from 4.30 to 6.70). Breslow distribution revealed a median value of 0.62 mm (mean 1.34; SD 2.24; range 0.09–30.0) and did not change significantly over time (P = 0.286). Higher Breslow values were observed at advanced age (P < 0.001), among males (P = 0.017), in nodular melanomas (P < 0.001) and at higher Clark levels (P < 0.001). Significant differences were also found in urban hospitals compared to rural hospitals during the whole period (P = 0.004), but not in the last 5 years (P = 0.053).
Conclusion
Incidence of cutaneous melanoma is increasing in South Tyrol, especially for in situ and thin lesions, but also for thick lesions; no reduction in median tumour thickness is observed. Rural areas and elevated altitudes may contribute to this effect.
Electrophysiological methods may help to unravel some of the pathophysiological mechanisms of migraine. Lack of habituation is the principal and most reproducible interictal abnormality in sensory ...processing in migraineurs. It is found in evoked potential (EP) studies for every stimulation modality including nociceptive stimuli, and it is likely to be responsible for the increased intensity dependence of EP. We have hypothesized that deficient EP habituation in migraine could be due to a reduced preactivation level of sensory cortices because of hypofunctioning subcortico-cortical aminergic pathways. This is not in keeping with simple hyperexcitability of the cortex, which has been suggested by some, but not all, studies of transcranial magnetic stimulation (TMS). A recent study of the effects of repetitive TMS on visual EP strongly supports the hypothesis that migraine is characterized by interictal cortical hypoexcitability.
With regard to pain mechanisms in migraine, electrophysiological studies of trigeminal pathways using nociceptive blink and corneal reflexes have confirmed that sensitization of central trigeminal nociceptors occurs during migraine attacks.
ABSTRACT
The nitrogen fixation by strains belonging to the Bacillus genus remains poorly explored. In this work, the diversity of endospore‐forming bacilli isolated from the rhizosphere of sunflower ...was evaluated. A total of 101 strains were identified based on the V1‐V2 variable regions of the 16S rRNA gene. Strains belonging to the genera Bacillus and Paenibacillus represented 41.6% and 58.4%, respectively, of total isolates. The production of indolic compounds was a common trait among the isolates, and approximately 75% of them exhibited positive nitrogenase activity; but only 9.2% displayed activities higher than 1 nmol C2H4 mg protein h−1. Within the genus Bacillus, the isolates related to the B. cereus group displayed the highest nitrogenase activity and were the second most frequent group of Bacillus sp. isolated. Plants inoculated with the isolate B38V showed the highest N content, and their shoot dry weights were significantly increased compared with positive control. Our results indicated that B38V, which belongs to the B. mycoides species, has the potential to promote sunflower growth. The data obtained in this study provide additional information concerning the diversity of Gram‐positive diazotrophic within the genera Bacillus and Paenibacillus and their potential for the biofertilisation of sunflower crops.
Work towards completion of the human reference genome sequence has revealed a great deal of complexity and plasticity in human subtelomeric regions. The highly variable subtelomeric repeat regions ...are filled with recently shuffled genomic segments, many of which contain sequences matching transcripts and transcript fragments; the rapid duplication and combinatorial evolution of these regions has generated an extremely diverse set of subtelomeric alleles in the human species, the complexity and potential significance of which is only beginning to be understood. This review summarizes recent progress in analyzing human subtelomeric sequence assemblies and large-scale variation in human subtelomere regions.
Basilar migraine (BM), familial hemiplegic migraine (FHM), and sporadic hemiplegic migraine (SHM) are phenotypically similar subtypes of migraine with aura, differentiated only by motor symptoms, ...which are absent in BM. Mutations in CACNA1A and ATP1A2 have been found in FHM. The authors detected a novel mutation in the ATP1A2 gene (R548H) in members of a family with BM, suggesting that BM and FHM may be allelic disorders.
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