Development of a new sensor based on micro-electro-mechanical systems for objective in vivo measurement of the cutaneous temperature: application to foundations

BACKGROUND/AIMS: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro-electro-mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made-up skin. METHODS: Sixteen female subjects divided into two different age groups (18-35 and >50 years old) were recruited for this study. Several zones of the face and forearms were made up at random with foundations containing or not a thermoregulator raw material. The quantity of foundation applied on the skin was standardized and measurements were carried out first before make-up, and then 10 s and 5 min after make-up. The new sensor and the thermocouple were used successively on each zone. The cutaneous temperature was expressed in degrees celsius. RESULTS/CONCLUSION: The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up.     

Correction of frequency and phase variations induced by eddy currents in localized spectroscopy with multiple echo times.

As a consequence of the time-varying magnetic field induced by eddy currents, frequency drifting occurs when the sampling window of localized spectroscopy continuously shifts. The frequency drifting and the concomitant phase variations can severely affect spectroscopy results when data are acquired with multiple echo times (TEs), such as in the measurement of glutamate (Glu) concentration using the TE-averaged method. Specifically, the averaged spectra are further broadened and distorted in the presence of residual eddy currents, and editing of the coupled spins of Glu C4 protons is affected, resulting in errors in the measured relative intensity ratio. Postacquisition correction using unsuppressed water as reference can effectively minimize this detrimental effect, as manifested by the significantly enhanced signal intensity. Also, it is demonstrated that the methyl signals of creatine (Cr) at 3.0 ppm and choline (Cho) at 3.2 ppm can be used as internal references in finding frequency and phase disparities between different TEs.     

Sources of stress in Australian adolescents: factor structure and stability over time

Adolescent stress is an emerging area of importance in considerations of the health of young people. Exposure to stress predicts a range of both physical and mental health problems in adolescents and relates, as well, to the initiation of important health risk behaviours. Yet the measurement of stress in adolescents has been as fraught with methodological difficulty as it has been for adults. This paper examines the Adolescent Stress Questionnaire (ASQ) which was developed specifically to address the domain of stressors specific to adolescent experience and looks at three cohorts of responses to this questionnaire over time (1995, 1998 and 2001). It assesses the stability of the original 7‐factor structure of the ASQ over time, and while confirmatory factor analysis indicates that stability to be acceptable, it also suggests that either adolescent stressors themselves, or the language by which they are reported, vary sufficiently over time to warrant the refinement of the instrument. Copyright © 2002 John Wiley & Sons, Ltd.     

Decreased hyperthermic effect of MK-801 in selectively bred hypercholinergic rats

The Flinders Sensitive Line (FSL) of rats has been selectively bred to have increased sensitivity to cholinergic agonists. However, these rats exhibit altered responsiveness to a number of noncholinergic agents, such as apomorphine, buspirone and ethanol. This study compared the FSL and control Flinders Resistant Line (FRL) rats in terms of their hyperthermic response to the phencyclidine (PCP) receptor agonist, MK-801 (0.2 mg/kg SC) and their MK-801 binding characteristics. We have found that FSL rats react with a delayed hyperthermia, having a significantly lower hyperthermia for the first 120 min of observation. Thereafter the response does not differ in FSL and FRL rats. Both groups had similar affinities and numbers of [3H]MK-801 binding sites in the hippocampus/cerebral cortex. Pretreatment with scopolamine (1 mg/kg SC) failed to affect MK-801-induced hyperthermia in either line of rats. These findings suggest that selective breeding of FSL rats attenuated the secondary mechanisms involved in the PCP receptor-mediated hyperthermic response. However, by itself cholinergic supersensitivity does not appear to be a major factor in the blunted responsiveness of FSL rats to MK-801.     

Postoperative pain management—clinical practice is still not optimal

Major progress in clinical pain assessment and management has been achieved in the last decade. More effective analgesic drugs and improved techniques for pain management have been introduced. However, medical reports published during the last few years on postoperative pain management (POPM) indicate that moderate or even severe pain is still rather commonly experienced by surgical patients in the early postoperative period and that worst-pain-episodes may occur even in the late postoperative phase. Insufficient relief of postoperative pain seems a more common problem on surgical wards than on a postanaesthesia care unit (PACU). The aims of POPM are to inhibit autonomic trauma-induced nociceptive impulses that may result in functional disturbances of vital organs and thereby affect the incidence of potentially severe complications influencing clinical outcome. Considering that recent studies continue to show sub-optimal pain management despite the availability of effective drugs and analgesic techniques it must be considered essential to identify possible barriers to effective pain management in clinical practice so that necessary improvements in POPM routines can be carried out.     

国人髌腱长度测量在髌骨不稳诊断中的意义

[目的]比较国人正常膝关节与髌骨不稳膝关节的髌腱长度,探讨国人髌腱长度的测量在髌骨不稳诊断中的意义。[方法]2003年1月~2005年12月诊治的43例髌骨不稳患者共49膝(男15例,女28例,6例为双侧髌骨不稳);平均年龄21.4岁(18~28岁);平均身高163(155~173)cm。正常对照组为50例健康体检者共50膝(男16例,女34例);平均年龄24.2岁(18~35岁);平均身高165(154~177)cm。在屈膝30°X线侧位片上测量髌腱长度、胫骨结节至胫骨平台的距离、Insall-Salvati指数。[结果]髌骨不稳组髌腱长度为(53.3±2.7)mm,对照组为(47.3 3.3)mm,统计学上具有显著差异性(P<0.05)。Insall-Salvati指数在髌骨不稳组(1.33±0.17)和对照组(1.06±0.14)也具统计学差异(P<0.05)。胫骨平台与胫骨结节之间的距离在髌骨不稳组为(27.8±3.6)mm,对照组为(28.9±4.1)mm,统计学上无显著性差异(P<0.05)。[结论]髌腱长度过长是髌骨不稳的重要特点之一。联合测量髌腱长度和Insall-Salvati指数有助于髌骨不稳的诊断。     

Effects of tracheal extubation on coronary blood flow,myocardial metabolism and systemic haemodynamic responses

Global coronary blood flow and metabolism were measured in seven patients on the first postoperative day following coronary revascularization to test the hypothesis that tracheal extubation produces adverse haemodynamic responses akin to those observed during tracheal intubation. Regional coronary flow and metabolic measurements were made in five of the seven patients. Extubation from a continuous positive airway pressure (CPAP) of 5 cm H₂O was associated with a statistically significant rise in cardiac index from 3.44 ± 0.23 L · min^-1 · m^-2 to 3.73 ± 0.15L·min^-1 ·m^-2 related to an increase in stroke index, without significant changes in heart rate, mean arterial and pulmonary capillary wedge pressure. Consequently the changes in myocardial oxygen consumption (8.52 ± 0.55 to 8.85 ± 0.93 ml · min^-1) and coronary blood flow (172 ± 18 to 179 ± 17 ml·min^-1) were less prominent than those reported during intubation, where substantial rises in myocardial oxygen consumption and coronary flow occurred. Two patients experienced cardiac lactate production but there were no changes in systemic or coronary haemodynamics, nor were there clinical or electrocardiographic signs of ischaemia. We conclude that extubation does not appear to be associated with adverse systemic or coronary haemodynamic responses in patients following coronary bypass grafting. However, the revascularized myocardium may remain vulnerable to anaerobic metabolism in the immediate postoperative period. Pour savoir si comme ľintubation, ľextubation de la trachée provoque des perturbations hémodynamiques, on a mesuré le métabolisme et la circulation coronarienne globale chez sept patients, au lendemain ďun pontage aorto-coronarien. On a aussi calculé les valeurs régionales de ces mêmes variables pour cinq ďentre eux. Ľindex cardiaque de 3.44 ± 0.23 L · min^-1 · m^-2 sous pression positive en respiration spontanée (CPAP) de 5 cm. H₂O s’est élevé à 3.73 ± 0.15 L · min^-1 · m^-2 post-extubation avec une augmentation significative du volume ďéjection. La fréquence cardiaque et les pressions artérielles moyennes et capillaires pulmonaires n’ont pas changé. Ainsi ľaugmentation de la consommation ďoxygène du myocarde de 8.52 ± 0.55 à 8.85 ± 0.93 ml · min^-1 et celle du flot coronarien de 172 ± 18 à 179 ± 17 ml · min^-1 ont été moindres que celles, importantes, déjà observées lors de ľintubation. On a noté chez deux patients une production de lactate par le myocarde, sans changement de ľhémodynamic systémique et coronarienne non plus que de signe clinique ou électrocardiographique ďischémie. Donc, après un pontage coronarien, ľextubation ne semble pas causer ďeffet néfaste sur les circulations systémique et coronarienne, toutefois, le myocarde revascularisé peut demeurer sensible au métabolisme anaérobique.     

A Simple Nephelometric Method for Measuring the Progressive Motility and Collecting Motile Spermatozoa

A simple method for collection and measurement of the progressive motility of spermatozoa was developed. The procedure consists of the spectrophotometric measurement of the increase in optical absorbance produced by the upward migration of spermatozoa in a high density medium of Ficoll 400. The suspension containing migrated spermatozoa may be used as a purified population of uniformly motile and undamaged spermatozoa.