ABSTRACT
An array of four independent laser traps is combined with a polydimethylsiloxane microfluidic chip to form a very compact system allowing parallel processing of biological objects. Strong three dimensional trapping allows holding objects such as functionalized beads in flows at speeds near 1 mm/s, enabling rapid processing. By pressure control of the inlet flows, the trapped objects can be put in contact with different solutions for analysis purpose. This setup, including a fluorescence excitation-detection scheme, offers the potential to perform complex biochemical manipulations on an ensemble of microparticles.
Subject(s)
Biological Assay/instrumentation , Cell Culture Techniques/instrumentation , Cell Separation/instrumentation , Flow Cytometry/instrumentation , Microfluidic Analytical Techniques/instrumentation , Micromanipulation/instrumentation , Optical Tweezers , Biological Assay/methods , Cell Culture Techniques/methods , Cell Separation/methods , Equipment Design , Equipment Failure Analysis , Flow Cytometry/methods , Flow Injection Analysis/instrumentation , Flow Injection Analysis/methods , Microfluidic Analytical Techniques/methods , Micromanipulation/methods , Microspheres , Reproducibility of Results , Sensitivity and Specificity , Specimen Handling/instrumentation , Specimen Handling/methods , Systems IntegrationSubject(s)
Leadership , Societies, Nursing/history , Collective Bargaining , History, 20th Century , PennsylvaniaSubject(s)
Societies, Nursing/history , History, 20th Century , Leadership , Pennsylvania , Professional AutonomyABSTRACT
With a goal to test the influence of individual traits of circadian rhythms on the tolerance of shiftwork a circadian questionnaire has been developed with the method of factors analysis. There are two scales in the final form of the questionnaire representing two chronobiological characteristics: morningness - eveningsness (circadian phase-position) and flexibility of the sleep-wake-rhythm. Sex- and age-norms exist for the two scales. Reliability and validity have been demonstrated. The results of an epidemiological study shows that the hypothesis of better adjustment to shiftwork of evening-types can not be verified. A better predictor of tolerance to shift work in terms of wellbeing seems to be the individual circadian trait flexibility of sleep-wake-rhythm.
Subject(s)
Circadian Rhythm , Work Schedule Tolerance , Work , Adaptation, Physiological , Adult , Aged , Female , Humans , Male , Middle Aged , Surveys and QuestionnairesSubject(s)
Occupational Medicine , Work , Female , Germany, East , Health Status , Humans , Male , Occupational Diseases/diagnosis , Psychology, Social , Textile Industry , Work Capacity EvaluationABSTRACT
The effects of weak intensity percutaneous peripheral stimulations (SPPc) on the transmission of nociceptive messages induced by stimulation of the dental pulp have been studied on anaesthetized cats. 1. The jaw opening reflex (ROG) and the evoked potentials in the thalamic center median (CM), by stimulation of the dental pulp, disappear after a mean of 30 min after the start of SPPc. 2. These effects are analogous to those obtained by stimulation of the periaqueductal gray matter (St.GC) or by I.V. morphine injection. 3. The I.V. injection of the morphine antagonist (Nalorphine) blocks both the effects of the SPPc and those of the St.GC. 4. The authors put forth the hypothesis of a common mechanism of action of the SPPc and the St.GC which, through the liberation of endogenous morphinomimetic substances, would activate descending inhibitor impulses.
Subject(s)
Brain/drug effects , Dental Pulp/innervation , Nalorphine/pharmacology , Nociceptors/drug effects , Synaptic Transmission/drug effects , Animals , Cats , Cerebral Aqueduct/drug effects , Electric Stimulation , Evoked Potentials/drug effects , Morphine/pharmacology , Reflex/drug effects , Skin/innervation , Thalamic Nuclei/drug effectsABSTRACT
Experiments have been performed in order to study the effects of percutaneous peripheral stimulation (PCPS) both on the transmission of messages elicited by recruiting sensory units of the tooth pulp at the thalamic Centrum Medianum Level and on the jaw opening reflex (JOR). Both evoked potentials and JOR were inhibited by stimuli applied to the limbs by means of percutaneous (needle) electrodes. Observed inhibitory effects were not immediate: there was a latency period and progressive induction of these phenomena. The site of the inhibition is still unknown, nevertheless, the demonstration that PCPS was able to inhibit both evoked potentials in Centrum Medianum and JOR support the hypothesis that the analgesic effects may be due to descending inhibition blocking transmission of nociceptive information through the spinal cord.
Subject(s)
Evoked Potentials , Nociceptors/physiology , Peripheral Nerves/physiology , Synaptic Transmission , Animals , Cats , Dental Pulp/innervation , Electric Stimulation/methods , Jaw/innervation , Recruitment, Neurophysiological , Thalamic Nuclei/physiologyABSTRACT
The blockade of effects induced by percutaneous peripheral stimulation were abolished by injection of an opiate antagonist as nalorphine. Our results lead to the hypothesis that central and peripheral stimulations act by the same mechanism in producing blockade of noxious impulses. One may suggest that peripheral stimulations induce release of endogenous morphine-like substances which in turn give descending inhibition.
Subject(s)
Nalorphine/pharmacology , Nociceptors/drug effects , Receptors, Opioid/drug effects , Analgesia , Animals , Cats , Electric Stimulation , Peripheral Nerves/physiology , Synaptic Transmission/drug effectsABSTRACT
UNLABELLED: The author's describe: I. METHODS OF ANALGESIC CUTANEOUS STIMULATION: I) Transcutaneous analgesic stimulation: Stimulations realized by biphasic asymetrical "waves" of 0 to 80 milliamps intensity for a frequency of 10 to 100 cycles/S. -Place of the stimulation: a painful area. -Stimulation length: 15 to 20 minutes, repeated during several days. RESULTS: appreciate patients tolerance to the tingling sensation. Test the analgesic effect, sometimes sufficient to treat the patient. 2) Analgesic percutaneous stimulation: The percutaneous electrode is applicated to the dura, without penetrating it. Same types of results as for transcuteneous stimulation but more precise. II. DEFINITION of the indication of chronic implantation of an analgesic stimulator. Studying results of repeated analgesic transcutaneous stimulations allows to distinguish between several possibilities. I) Intolerance of the sensation of stimulation: Contra-Indication or increasing of the pain. 2) Complete and lasting amelioration leads to: Chronic transcutaneous neurostimulation. 3) Partial amelioration, No amelioration leads to: Acute percutaneous stimulation either successful results after stimulation, : Chronic implantation: -of peripheral nerve -on a peripheric nerve -of dorsal column -on dorsal column, either paraesthesis without Analgesia:? III - EXPERIMENTAL APPROACH TO THE MECHANISM OF ACTION OF THE "ANALGESIANT" ELECTRIC STIMULATION. A cutaneous "analgesiant" stimulation produces, in the cat, the inhibition of evocated potential in C.M. by "nociceptive" stimulation of the sciatic nerve. The inhibition only appears after a 30 minutes latence. This let suppose different mechanisms from the "Gate Control" theory. The authors specify their personal results (Tab. 2.)
