Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace.

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace.

Light-emitting diodes (LED) for domestic lighting: any risks for the eye?

Light-emitting diodes (LEDs) are taking an increasing place in the market of domestic lighting because they produce light with low energy consumption. In the EU, by 2016, no traditional incandescent light sources will be available and LEDs may become the major domestic light sources. Due to specific spectral and energetic characteristics of white LEDs as compared to other domestic light sources, some concerns have been raised regarding their safety for human health and particularly potential harmful risks for the eye. To conduct a health risk assessment on systems using LEDs, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), a public body reporting to the French Ministers for ecology, for health and for employment, has organized a task group. This group consisted physicists, lighting and metrology specialists, retinal biologist and ophthalmologist who have worked together for a year. Part of this work has comprised the evaluation of group risks of different white LEDs commercialized on the French market, according to the standards and found that some of these lights belonged to the group risk 1 or 2. This paper gives a comprehensive analysis of the potential risks of white LEDs, taking into account pre-clinical knowledge as well as epidemiologic studies and reports the French Agency's recommendations to avoid potential retinal hazards.

Arthrolysis in the treatment of ankylosis and severe post traumatic stiffness of the elbow.

Between 1977 and 1989 the authors performed arthrolysis on 18 patients with ankylosis or severe post traumatic elbow stiffness. After an analysis of the cases, the operative technique is described and original parameters are proposed to evaluate the consequent results. The validity of arthrolysis as a possible alternative to arthroplasty or arthroprosthesis is confirmed by the 67% positive results.

Use of the Ilizarov apparatus in one case of severe congenital dysmetria of the leg with agenesis of the foot.

The authors present one case of severe congenital dysmetria of the leg with agenesis of the foot which was treated by the Ilizarov method. After a clinical and radiographic description of the case, the type of surgery used to create a new foot and the results obtained are discussed.

[Orthostatic hypotension in the elderly]. / L'ipotensione ortostatica nell'anziano.

The physiological answer to the orthostatic stress and changes in the elderly are examined. Moreover therapy of orthostatic hypotension, either pharmacological or not is reviewed.

Zinc and thymic hormone-dependent immunity in normal ageing and in patients with senile dementia of the Alzheimer type.

Plasma zinc levels were measured in young controls, aged controls, patients with dementia of the Alzheimer type and patients with non-Alzheimer type dementia. Zinc levels decreased with age; however, no difference was found between patients with dementia and age-matched controls. Plasma levels of active or inactive thymulin, a nonapeptide produced and released by the thymus gland, were also determined in young controls, aged controls, patients with dementia of the Alzheimer type and patients with non-Alzheimer type dementia. Basal levels of active thymulin were decreased in aged controls and in patients with dementia. In vitro reactivation of thymulin after zinc addition to plasma samples was decreased in aged controls. A further impairment of thymulin reactivation was present in patients with dementia. A significant age-dependent decrease in lymphocyte proliferation after mitogen stimulation was found; however, no difference was present between aged controls and patients with dementia of the Alzheimer type. Interleukin-2-induced cell activation and its effect on mitogen-induced proliferation were also measured; once again only an age-associated decrease was found. The endocrine function of the thymus of patients with dementia appears to be more compromised than that from aged controls.

Stable osteosynthesis by the AO method in comminuted intra-articular fractures of the distal humerus.

The authors report their experience between 1982 and 1986 in 16 cases of comminuted supraintercondylar fractures of the elbow treated by stable osteosynthesis using the AO method with immediate or early mobilisation. They illustrate the technical possibility of obtaining stable synthesis even in fractures with numerous fragments and analyse the long-term functional results. Because of the severity of the fracture, none of the patients recovered full flexion and extension of the elbow; nonetheless in all the patients there was recovery of at least 90 degrees of movement and, most importantly, this occurred in the most useful range of movement. These results, and the time required for healing, amply justify the use of solid synthesis in fractures where the alternative would be arthroplasty.

Transposition of the 5th to the 4th ray by osteotomy of the hamate.

The authors present 5 cases of transposition of the 5th to the 4th ray according to Le Viet's method. This is indicated for the aesthetic and functional defects that follow total or subtotal amputation of the ring finger. The technique consists of radial transposition of the whole ray and intracarpal arthrodesis after cuneiform osteotomy of the hamate bone. It is easier to perform than the traditional metacarpal osteotomy and the results were uniformly good.

[What is in the future for geriatrics? I]. / Quale futuro per la geriatria? Prima parte.

The authors, after an evaluation of the historical course of the geriatrics in England and its contents, point out the importance of this specialty from a demografic, economical, social, epidemiological and cultural point of view.

[What is in the future for geriatrics? II]. / Quale futuro per la geriatria? Seconda parte.

The authors point out the importance of geriatric medicine in the hospital in its traditional goals and in some new proposals: geriatric case finding, general practitioner's education, teaching in nursing schools, family education, pre-retirement courses etc.