Revisiting the Hydrogen Storage Behavior of the Na-O-H System

Solid-state reactions between sodium hydride and sodium hydroxide are unusual among hydride-hydroxide systems since hydrogen can be stored reversibly. In order to understand the relationship between hydrogen uptake/release properties and phase/structure evolution, the dehydrogenation and hydrogenation behavior of the Na-O-H system has been investigated in detail both ex- and in-situ. Simultaneous thermogravimetric-differential thermal analysis coupled to mass spectrometry (TG-DTA-MS) experiments of NaH-NaOH composites reveal two principal features: Firstly, an H₂ desorption event occurring between 240 and 380 °C and secondly an additional endothermic process at around 170 °C with no associated weight change. In-situ high-resolution synchrotron powder X-ray diffraction showed that NaOH appears to form a solid solution with NaH yielding a new cubic complex hydride phase below 200 °C. The Na-H-OH phase persists up to the maximum temperature of the in-situ diffraction experiment shortly before dehydrogenation occurs. The present work suggests that not only is the inter-phase synergic interaction of protic hydrogen (in NaOH) and hydridic hydrogen (in NaH) important in the dehydrogenation mechanism, but that also an intra-phase H^δ+… H^δ– interaction may be a crucial step in the desorption process.     

Tinea faciei starting at day two of life

Dermatophyte infections are exceedingly rare in neonates, possibly due to the thin stratum corneum and high sebum content of neonatal skin. Only a handful of cases of tinea faciei have been reported in neonates, with the majority of reports occuring in India. Here, we report what to our knowledge is the earliest reported presentation of tinea faciei in the United States. We also provide a brief literature review of other reported cases of tinea faciei in neonates less than 30 days of age.     

Skin problems after a tsunami

BACKGROUND: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. OBJECTIVE: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. METHODS: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia. RESULTS: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. CONCLUSIONS: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.     

Differential effects of cannabis extracts and pure plant cannabinoids on hippocampal neurones and glia

We have shown previously that the plant cannabinoid cannabidiol (CBD) elevates intracellular calcium levels in both cultured hippocampal neurones and glia. Here, we investigated whether the main psychotropic constituent of cannabis, Δ⁹-tetrahydrocannabinol (THC) alone or in combination with other cannabis constituents can cause similar responses, and whether THC affects the responses induced by CBD. Our experiments were performed with 1 μM pure THC (pTHC), with 1 μM pure CBD (pCBD), with a high-THC, low CBD cannabis extract (eTHC), with a high-CBD, low THC cannabis extract (eCBD), with a mixture of eTHC and eCBD (THC:CBD = 1:1) or with corresponding ‘mock extracts’ that contained only pTHC and pCBD mixed in the same proportion as in eTHC, eCBD or the 1:1 mixture of eTHC and eCBD.     

Ultrastructural observations of organelle accumulation in the equine recurrent laryngeal nerve

Summary The left recurrent laryngeal nerves from five horses with sub-clinical neuropathy were examined by light and electron microscopy in a study designed to examine accumulation of axonal organelles at paranodal and internodal locations. Transverse sections of the nerve showed scattered fibres with split myelin sheaths and axonal accumulation of organelles. On longitudinal sections these collections were seen to result from an axonal outpouching in which dense lamellar bodies and mitochondria had accumulated. These paranodal collections, which could be found on both sides of the node, were often associated with infoldings of the terminal loops of myelin and with occasional paranodal demyelination. The fact that many of the organelles in the outpouches were lysosomal in nature was confirmed by their positive staining for cathepsin D activity. Longitudinal sections demonstrated a number of axons which were swollen over a long distance and which contained focal accumulations of similar organelles. In places, however, there was a clear separation between these organelles and the cytoskeletal proteins. In each case these swollen axons were surrounded by Schwann cell nuclei and their processes, forming well-ordered onion bulbs. The possibility that these two types of changes, i.e. the paranodal accumulations and the axonal swellings could result from a disturbance in axonal transport in this distal axonopathy is discussed.     

Prognosis of epilepsy

It has been a widely accepted view that epilepsy is usually a chronic condition in which the prognosis is generally poor and any remissions that do occur are usually temporary. In this article recent studies challenging this view will be considered, other aspects of the long-term prognosis for seizure control in epilepsy reviewed, and the mortality rates and causes of premature death in epilepsy outlined.