Developing new industrial applications for gold: Gold nanotechnology

Nanotechnology has transformed gold from a marginal into a very effective catalyst with unique properties. The astounding growth in gold nanoparticle research, as reflected in publications and patents, now promises new materials applications for gold nanotechnology and some possibilities are indicated in this article.     

Effects of bipiperidyl mustard (BPM) lesions on insulin hypoglycemic convulsions

Systemic gold thioglucose (GTG) is well known to produce hyperphagia, resulting in obesity, and histological damage focused relatively selectively in the ventromedial hypothalamus (VMH). Although structurally very different, bipiperidyl mustard (BPM) produces apparently similar effects. However, a proposed mechanism for concentration and hence localization of GTG toxicity depends on its structural similarity to glucose, binding it to glucoreceptors and focusing the cytotoxicity of the gold thio-portion. We recently showed that GTG treatment also produces an early decrease and a later increase in sensitivity to insulin hypoglycemic convulsions. We report here that BPM also produces a similar biphasic change in sensitivity to insulin hypoglucemic convulsions. For both, the differences are in the brain's convulsive response to hypoglycemia, rather than in the degree of hypoglycemia in response to insulin. Thus, GTG and BPM cytotoxic lesions appear similar in this regard as well. BPM is another way of producing a relatively discrete brain lesion which alters the brain's functional adjustment to hypoglycemia. The significance of this control center and its relationship to the control(s) of feeding and systemic metabolism are discussed.     

Sensory nerve conduction velocity: technical requirements and normal values for branches of the radial and ulnar nerves of the dog

Conduction velocities of compound action potentials of sensory axons of alteral superficial radial (LSR) and dorsal ulnar nerves (DUN) of the dog were determined by averaging potentials evoked and recorded through subcutaneous needle electrodes. Suitable locations for electrodes were identified and specificities of sites for LSR and DUN were verified by recording before and after cutting the nerves. Stimulus rates of 4/second to 20/second did not markedly affect conduction velocities. Increasing stimulus intensity in steps from threshold to 8 X threshold recruited more axons into the compound action potentials but resulted in interference from movement and muscle potentials at 4 X or 8 X threshold. Mean conduction velocities at 2 X threshold were: LSR = 61.7 +/- 0.76 SEM; DUN = 68.1 +/- 2.71 SEM.     

The effects of caregiver experience on low back loads during floor and overhead lift maneuvering activities

This study investigated the effects of caregiver experience on peak external forces and moments generated at the L5/S1 joint of the low back when maneuvering loaded floor-based and overhead-mounted patient lifting devices. Twenty caregivers were divided into more-experienced and less-experienced groups based on the product of two factors: their years of lifting experience and the frequency of lifting the caregivers had done in the past. Ground reaction forces and moments as well as motion capture data were recorded while caregivers performed five different maneuvering tasks with both lifts in each of three conditions (caregiver subjects worked alone, as the primary caregiver in a pair, and as the secondary caregiver in a pair). Six outcome measures (net external forces and moments at the L5/S1 joint) were recorded. Multivariate analyses of variance of all net external forces and moments were done separately for the floor and overhead lifts. A significant effect of experience level was found for the floor lift (p = 0.006) but not for the overhead lift (p = 0.163). A follow-up univariate analysis of floor lift activities found significant differences between more-experienced and less-experienced caregivers for Turn, Push and Legs Up activities.

Relevance to industry

Previous work has shown that overhead lifts reduce the loads on caregivers compared to floor lifts. The findings of this study further underscore the need to purchase overhead lifts to protect less-experienced caregivers (including informal family caregivers) who are at increased risk of back injury when maneuvering floor lifts.     

Impact of Low-Temperature Neutron Irradiation on Tensile Behavior of Base Metal and Electron-Beam Welded 316L Stainless Steel

Metallurgical and Materials Transactions A - A study of 316L type stainless steel in its base metal and electron-beam (e-beam) welded conditions was performed to observe the effects of...     

Medical Applications Of In-Vitro X-Ray Fluorescence

ABSTRACT

Stable tracers are safe, convenient and readily available, but their use entails the need for involved assay techniques. X-ray fluorescence combines the use of stable tracers with the convenience of radioactive quantitation techniques. An automated system has been developed for use in medicine. Its performance and applications are presented.     

In search of the cognitive map: Can rats learn an abstract pattern of rewarded arms on the radial maze?

Five experiments were performed to examine rats' abilities to form an abstract cognitive map of the pattern of baited arm locations on a radial maze and to recognize that pattern when it was moved to a new location. Following an initial period of training with patterns of rewarded and nonrewarded arms (Exps 1 and 2) or with patterns of different quantities of reward (Exp 3), a test phase was carried out in which the initial pattern was rotated varying distances around the maze. In Exps 4 and 5, testing was carried out in an environment different from the one used in training. All 5 experiments failed to yield any evidence that rats learned a geometric or topographical representation of a pattern of reward locations that could be transferred to a new placement of the pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of maternal weight measurements during antenatal care. A national survey of midwifery practice throughout the United Kingdom

The aim of the present study was to examine the use of maternal weight measurements during antenatal care throughout the United Kingdom. A postal questionnaire and follow-up letter were sent to 1500 midwives throughout the United Kingdom, selected at random from the UKCC register. The postal survey achieved a response rate of 44.8% (672/1500 questionnaires), and obtained responses from at least 10 midwives in all but the lowest grade. Respondents were representative of midwives practising throughout the country, in terms of their gender, working hours and grade, although there were fewer midwives in community settings than those in a contemporary representative English sample. The questionnaire obtained information on the background, training and experience of each midwife, together with their attitudes towards antenatal weighing. For those midwives currently involved in antenatal care, additional information was collected on the schedule of antenatal weight measurements, the criteria used to identify 'abnormal' weight gain, and the action taken in response to 'abnormal' weight gain. 61.8% of the midwives thought that the pattern of maternal weight gain was 'not important' in antenatal care, and only 51.5% of those who currently provided antenatal care weighted women at every antenatal visit. However, most midwives (86.1%) cited at least one clinical condition to explain why women are routinely weighed during pregnancy, and over a third of midwives thought that maternal weight gain could detect seven clinical conditions, including obesity, oedema, pre-eclampsia and polyhydramnios. Midwives with more advanced qualifications (degrees and teaching qualifications) and those working in educational or community settings were least likely to believe that weight gain was good at detecting clinical outcomes. Differences in the perceived utility of antenatal weighing influenced whether midwives would act in response to 'abnormal' maternal weight gain, and whether they advised women to gain or lose weight during pregnancy. However, the criteria that midwives used for identifying 'abnormal' weight gain were variable, and often inappropriate, so that different midwives are unlikely to intervene consistently or to give consistent advice on the basis of maternal weight gain. These differences in practice may lead to extensive and inappropriate variation in antenatal care. Clear guidelines are urgently required to ensure that, if maternal weight measurements are collected during antenatal care, they are collected and used consistently.