Electrochemical Evaluation of LaNi_(5–x)Ge_x Metal Hydride Alloys

We report a detailed evaluation of Ge-substituted LaNi_5 for electrochemical application as a negative electrode in alkaline rechargeable cells. Alloys with small substitutions of Ge for Ni show operating pressures, chargeability, cyclic lifetime, and kinetics for hydrogen absorption and desorption all superior to those found in many other substituted LaNi_5 alloys. These improved properties were achieved with a minimal reduction in hydrogen storage capacity

Electrochemical Studies on LaNi5–xSnx Metal Hydride Alloys

Electrochemical studies were performed on LaNi5–xSnx with 0 <= x <= 0.5. We measured the effect of the Sn substituent on the kinetics of charge-transfer and diffusion during hydrogen absorption and desorption, and the cyclic lifetimes of LaNi5–-xSnx electrodes in 250 mAh laboratory test cells. We report beneficial effects of making small substitutions of Sn for Ni in LaNi5 on the performance of the metal hydride alloy anode in terms of cyclic lifetime, capacity, and kinetics. The optimal concentration of Sn in LaNi5–xSnx alloys for negative electrodes in alkaline rechargeable secondary cells was found to lie in the range 0.25 <= x <= 0.3

Electrochemical Properties of LaNi5–xGex Alloys in Ni-MH Batteries

Electrochemical studies were performed on LaNi5–xGex metal hydride alloys with 0 <= x <= 0.5. We carried out single-electrode studies to understand the effects of the Ge substituent on the hydrogen absorption characteristics, the electrochemical capacity, and the electrochemical kinetics of hydrogen absorption and desorption. The electrochemical characteristics of the Ge-substituted alloys are compared to those of the Sn-substituted alloys reported earlier. LaNi5–xGex alloys show compositional trends similar to LaNi5–xSnx alloys, but unlike the Sn-substituted alloys, Ge-substituted alloys continue to exhibit facile kinetics for hydrogen absorption/desorption at high solute concentrations. Cycle lives of LaNi5–xGex electrodes were measured in 300 mAh laboratory test cells and were found to be superior to the Sn-substituted LaNi5 and comparable to a Mm(Ni,Co,Mn,Al)5 alloy. The optimum Ge content for LaNi5–xGex metal hydride alloys in alkaline rechargeable cells is in the range 0.4 <= x <= 0.5

Hydrogen adsorption and cohesive energy of single-walled carbon nanotubes

Hydrogen adsorption on crystalline ropes of carbon single-walled nanotubes (SWNT) was found to exceed 8 wt.%, which is the highest capacity of any carbon material. Hydrogen is first adsorbed on the outer surfaces of the crystalline ropes. At pressures higher than about 40 bar at 80 K, however, a phase transition occurs where there is a separation of the individual SWNTs, and hydrogen is physisorbed on their exposed surfaces. The pressure of this phase transition provides a tube-tube cohesive energy for much of the material of 5 meV/C atom. This small cohesive energy is affected strongly by the quality of crystalline order in the ropes

Corticospinal Inputs to Primate Motoneurons Innervatingthe Forelimb from Two Divisions of Primary Motor Cortexand Area 3a

Previous anatomical work in primates has suggested that only corticospinal axons originating in caudal primary motor cortex (“newM1”) and area 3a make monosynaptic cortico-otoneuronal connections with limb motoneurons.By contrast, the more rostral “old M1” is proposed to control motoneurons disynaptically via spinal interneurons. In six macaque monkeys, we examined the effects from focal stimulation within old and new M1 and area 3a on 135 antidromically identified motoneurons projecting to the upper limb. EPSPs withsegmental latency shorter than 1.2 ms were classified as definitively monosynaptic; these were seen only after stimulation within new M1or at the new M1/3a border (incidence 6.6% and 1.3%, respectively; total n=27). However, most responses had longer latencies. Usingmeasures of the response facilitation after a second stimulus compared with the first, and the reduction in response latency after a third stimulus compared with the first, we classified these late responses as likely mediated by either long-latency monosynaptic (n=108) ornon-monosynaptic linkages (n=108). Both old and new M1 generated putative long-latency monosynaptic and non-monosynaptic effects; the majority of responses from area 3a were non-monosynaptic. Both types of responses from new M1 had significantly greateramplitude than those from old M1. We suggest that slowly conducting corticospinal fibers from old M1 generate weak late monosynaptic effects in motoneurons. These may represent a stage in control of primate motoneurons by the cortex intermediate between disynapticoutput via an interposed interneuron seen in nonprimates and the fast direct monosynaptic connections present in new M1.This work was supported by the Wellcome Trust

Do ACE inhibitors improve the response to exercise training in functionally impaired older adults? A randomized controlled trial

&lt;br&gt;Background: Loss of muscle mass and strength with ageing is a major cause for falls, disability, and morbidity in older people. Previous studies have found that angiotensin-converting enzyme inhibitors (ACEi) may improve physical function in older people. It is unclear whether ACEi provide additional benefit when added to a standard exercise training program. We examined the effects of ACEi therapy on physical function in older people undergoing exercise training.&lt;/br&gt; &lt;b&gt;Methods:&lt;/b&gt; Community-dwelling people aged ≥65 years with functional impairment were recruited through general (family) practices. All participants received progressive exercise training. Participants were randomized to receive either 4 mg perindopril or matching placebo daily for 20 weeks. The primary outcome was between-group change in 6-minute walk distance from baseline to 20 weeks. Secondary outcomes included changes in Short Physical Performance Battery, handgrip and quadriceps strength, self-reported quality of life using the EQ-5D, and functional impairment measured using the Functional Limitations Profile.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results:&lt;/b&gt; A total of 170 participants (n = 86 perindopril, n = 84 placebo) were randomized. Mean age was 75.7 (standard deviation [SD] 6.8) years. Baseline 6-minute walk distance was 306 m (SD 99). Both groups increased their walk distance (by 29.6 m perindopril, 36.4 m placebo group) at 20 weeks, but there was no statistically significant treatment effect between groups (−8.6m [95% confidence interval: −30.1, 12.9], p = .43). No statistically significant treatment effects were observed between groups for the secondary outcomes. Adverse events leading to withdrawal were few (n = 0 perindopril, n = 4 placebo).&lt;p&gt;&lt;/p&gt; &lt;b&gt;Interpretation:&lt;/b&gt; ACE inhibitors did not enhance the effect of exercise training on physical function in functionally impaired older people.&lt;p&gt;&lt;/p&gt

A 15 year record of high-frequency, in situ measurements of hydrogen at Mace Head, Ireland

Continuous high-frequency measurements of atmospheric molecular hydrogen have been made at Mace Head atmospheric research station on the west coast of Ireland from March 1994 to December 2008. The presented data provides information on long term trends and seasonal cycles of hydrogen in background northern hemispheric air. Individual measurements have been sorted using a Lagrangian dispersion model to separate clean background air from regionally polluted European air masses and those transported from southerly latitudes. No significant trend was observed in background northern hemispheric air over the 15 year record, elevations in yearly means were accounted for from large scale biomass burning events. Seasonal cycles show the expected pattern with maxima in spring and minima in late autumn. The mean hydrogen mole fraction in baseline northern hemispheric air was found to be 500.1 ppb. Air transported from southerly latitudes showed an elevation from baseline mean of 11.0 ppb, reflecting both the latitudinal gradient of hydrogen, with higher concentrations in the Southern Hemisphere, and the photochemical source of hydrogen from low northern latitudes. European polluted air masses arriving at Mace Head showed mean elevation of 5.3 ppb from baseline air masses, reflecting hydrogen's source from primary emissions like fossil fuel combustion. Forward modelling of transport of hydrogen to Mace Head suggests that the ratio of hydrogen to carbon monoxide in primary emissions is considerably less in non-traffic sources than traffic sources

Current practice in the diagnosis and management of sarcopenia and frailty – results from a UK-wide survey

Objectives: Despite a rising clinical and research profile, there is limited information about how frailty and sarcopenia are diagnosed and managed in clinical practice. Our objective was to build a picture of current practice by conducting a survey of UK healthcare professionals. Methods: We surveyed healthcare professionals in NHS organisations, using a series of four questionnaires. These focussed on the diagnosis and management of sarcopenia, and the diagnosis and management of frailty in acute medical units, community settings and surgical units. Results: Response rates ranged from 49/177 (28%) organisations for the sarcopenia questionnaire to 104/177 (59%) for the surgical unit questionnaire. Less than half of responding organisations identified sarcopenia; few made the diagnosis using a recognised algorithm or offered resistance training. The commonest tools used to identify frailty were the Rockwood Clinical Frailty Scale or presence of a frailty syndrome. Comprehensive Geriatric Assessment was offered by the majority of organisations, but this included exercise therapy in less than half of cases, and medication review in only one-third to two-thirds of cases. Conclusions: Opportunities exist to improve consistency of diagnosis and delivery of evidence-based interventions for both sarcopenia and frailty