Abstract: A dry test piece for measuring a magnesium concentration in a biological fluid, which comprises the following reagent components (i) to (iii): (i) o-cresolphthalein complexon; (ii) O,O'-bis(2-aminophenyl)ethylene glycol-N,N,N',N'-tetraacetic acid; and (iii) a pH buffer agent of pH 8.5 to 11.0.

Abstract: A rear wheel turning mechanism in a four wheel steering system includes a rear wheel turning rod which is connected to the rear wheels of the vehicle and is adapted such that it can be displaced and thereby turn the rear wheels. An electric motor is operatively connected to the rear wheel turning rod and the steering wheel and displaces the rear wheel turning rod, thereby causing the rear wheels to turn in response to operation of the steering wheel. A rear-wheel-neutralizing spring urges the rear wheel turning rod to the neutral position in which the rear wheels are held in the straight-ahead position. A pair of clutches are interposed in series between the electric motor and the rear wheel turning rod and are adapted such that they disconnect the latter from the former, which permits the latter to return to the neutral position under the force of the rear-wheel-neutralizing spring.