Fe-Ni-based alloys as highly active and low-cost oxygen evolution reaction catalyst in alkaline media.

NiFe-based oxo-hydroxides are highly active for the oxygen evolution reaction but require complex synthesis and are poorly durable when deposited on foreign supports. Herein we demonstrate that easily processable, Earth-abundant and cheap Fe-Ni alloys spontaneously develop a highly active NiFe oxo-hydroxide surface, exsolved upon electrochemical activation. While the manufacturing process and the initial surface state of the alloys do not impact the oxygen evolution reaction performance, the growth/composition of the NiFe oxo-hydroxide surface layer depends on the alloying elements and initial atomic Fe/Ni ratio, hence driving oxygen evolution reaction activity. Whatever the initial Fe/Ni ratio of the Fe-Ni alloy (varying between 0.004 and 7.4), the best oxygen evolution reaction performance (beyond that of commercial IrO2) and durability was obtained for a surface Fe/Ni ratio between 0.2 and 0.4 and includes numerous active sites (high NiIII/NiII capacitive response) and high efficiency (high Fe/Ni ratio). This knowledge paves the way to active and durable Fe-Ni alloy oxygen-evolving electrodes for alkaline water electrolysers.

Low cost 3D printing of metals using filled polymer pellets.

Nowadays, additive manufacturing of metallic materials is most often carried out using expensive and complex tools that leave the user with limited control and no possibility of modification. In order to make the printing of metal parts more accessible to small structures but also better suited for academic research, the use of a mixture of thermoplastic polymer and metal powder is a good solution as many granular feedstocks already exist for Metal Injection Molding applications. To perform the shaping process, the Fused Granular Fabrication 3D printing technology is set up by diverting the use of a feedstock in the form of pellets that are directly inserted into the print head. This solution, which is less costly, is implemented here by modifying a mid-range printer, the Tool Changer from E3D, and by making the hardware and software adaptations to mount a compact granulates extruder on it, which is also available on the market. The polymer portion present in the green part can then be removed in order to perform the heat treatments that will densify the powder by sintering and give a fully metallic dense object.

Sex Differences in Neuromuscular Fatigue and Changes in Cost of Running after Mountain Trail Races of Various Distances.

INTRODUCTION: Women have been shown to experience less neuromuscular fatigue than men in knee extensors (KE) and less peripheral fatigue in plantar flexors (PF) after ultratrail running, but it is unknown if these differences exist for shorter trail running races and whether this may impact running economy. The purpose of this study was to characterize sex differences in fatigability over a range of running distances and to examine possible differences in the postrace alteration of the cost of running (Cr). METHODS: Eighteen pairs of men and women were matched by performance after completing different races ranging from 40 to 171 km, divided into SHORT versus LONG races (<60 and >100 km, respectively). Neuromuscular function and Cr were tested before and after each race. Neuromuscular function was evaluated on both KE and PF with voluntary and evoked contractions using electrical nerve (KE and PF) and transcranial magnetic (KE) stimulation. Oxygen uptake, respiratory exchange ratio, and ventilation were measured on a treadmill and used to calculate Cr. RESULTS: Compared with men, women displayed a smaller decrease in maximal strength in KE (-36% vs -27%, respectively, P < 0.01), independent of race distance. In SHORT only, women displayed less peripheral fatigue in PF compared with men (Δ peak twitch: -10% vs -24%, respectively, P < 0.05). Cr increased similarly in men and women. CONCLUSIONS: Women experience less neuromuscular fatigue than men after both "classic" and "extreme" prolonged running exercises but this does not impact the degradation of the energy Cr.

Headache characteristics and burden from chronic migraine with medication overuse headache: Cross-sectional observations from the Medication Overuse Treatment Strategy trial.

OBJECTIVE: To describe headache characteristics, medication use, disability, and quality of life in a large patient cohort from the United States who have chronic migraine (CM) and medication overuse headache (MOH). METHODS: In all, 610 adult patients were enrolled into the Medication Overuse Treatment Strategy trial from 34 healthcare clinics, including headache specialty, general neurology, and primary care clinics. Descriptive statistics characterize baseline demographics, headache characteristics, medication use, disability (Headache Impact Test 6 [HIT-6] and Migraine Functional Impact Questionnaire [MFIQ]), pain interference (PROMIS Pain Interference), and quality of life (EQ-5D-5L). Relationships with headache frequency were assessed. RESULTS: Mean age was 45 years (SD 13) and 531/608 (87.3%) were females. Mean headache days per 30 was 24.3 (SD 5.5), including 13.6 (SD 7.1) with moderate to severe headache. Daily headaches were reported by 36.1% (219/607) of patients. Acute headache medications were used on 21.5 (SD 7.5) per 30 days. The most commonly overused medications were simple analgesics (378/607, 62% of patients), combination analgesics (246/607, 41%), and triptans (128/607, 21%). HIT-6, MFIQ, PROMIS Pain Interference, and EQ-5D-5L scores demonstrated substantial negative impact from CM with MOH on patient functioning and quality of life. Higher headache frequency was associated with more moderate-severe headache days, more frequent acute headache medication use, greater headache-related disability, and lower quality of life. Only 272/606 (44.9%) were taking migraine preventive medication. CONCLUSIONS: CM with MOH is associated with a large burden on patients in the United States. Higher headache frequency is associated with greater impact on functioning, pain interference, and quality of life.

Assessment of the H-reflex using two synchronized magnetic stimulators in order to increase stimulus durations: A comparison with electrical stimulation.

Magnetic nerve stimulation (MNS) may be a less painful alternative to electrical nerve stimulation (ENS) for Hoffmann reflex (H-reflex) measurement, however standard MNS (sMNS) techniques utilize a short stimulus duration, thereby limiting its use for H-reflex assessment. This limitation may be partly overcome by coupling two magnetic stimulators to increase the pulse duration (coupled MNS: cMNS). The aim of this study was to test this assumption by comparing the H-reflex characteristics evoked by ENS, sMNS and cMNS. Thirteen healthy volunteers were tested with ENS and both MNS in the prone position. Maximal soleus H-reflex (Hmax) and M-wave (Mmax) amplitudes were measured to compute the Hmax/Mmax ratio. Hmax was evoked at rest and during both isometric submaximal (10%MVC) and maximal plantar-flexions (MVC). At rest, MNS techniques underestimated Hmax (ENS: 8.32 ±â€¯2.73 mV; sMNS: 6.85 ±â€¯2.29 mV; cMNS: 7.48 ±â€¯2.23 mV; p < 0.05). In contrast, no difference was observed for Hmax/Mmax (ENS: 0.59 ±â€¯0.17; sMNS: 0.45 ±â€¯0.28; cMNS: 0.47 ±â€¯0.29; p = 0.11). sMNS, cMNS and ENS similarly detected Hmax facilitation during MVC (ENS: +120 ±â€¯248%; sMNS: +228 ±â€¯350%; cMNS: +162 ±â€¯180% of the rest value; p = 0.344). Owing to their shorter stimulus duration, both MNS techniques underestimated the Hmax compared to ENS. However, when the gold standard ENS technique cannot be used, coupled MNS may be recommended since it provides better H-reflex characteristic assessment than standard MNS due to its longer stimulus duration.

Spatial risk assessment of Rift Valley fever in Senegal.

Rift Valley fever (RVF) is broadening its geographic range and is increasingly becoming a disease of global importance with potentially severe consequences for human and animal health. We conducted a spatial risk assessment of RVF in Senegal using serologic data from 16,738 animals in 211 locations. Bayesian spatial regression models were developed with interpolated seasonal rainfall, land surface temperature, distance to perennial water bodies, and time of year entered as fixed-effect variables. Average total monthly rainfall during December-February was the most important spatial predictor of risk of positive RVF serologic status. Maps derived from the models highlighted the lower Senegal River basin and the southern border regions of Senegal as high-risk areas. These risk maps are suitable for use in planning improved sentinel surveillance systems in Senegal, although further data collection is required in large areas of Senegal to better define the spatial distribution of RVF.

Migraine and women's health.

Migraine is a significant women's health concern. Epidemiological research has demonstrated that migraine is one of the most common pain conditions and that women are disproportionately affected. Recent advances in pathophysiology highlight the hormonal antecedents of these sex differences in migraine and the potential influence of hormones on migraine pain pathways. Migraine spawns substantial suffering and disability and gives rise to great economic and personal burden. Despite the availability of effective pharmacological and nonpharmacological treatments, only a fraction of migraine sufferers receive state-of-the-art treatment. Access to effective treatment is limited by economic and social barriers to care, including the long-standing social stigma that trivializes headache. Although doubtless a women's health issue, migraine has been largely overlooked in the women's health initiatives. This paper argues that migraine is an important women's health concern and that greater attention to migraine promises to make a demonstrable improvement in the quality of life of many women.