Multimodal Imaging of... Klin Monatsbl Augenheilkd hamartoma or the splenic hamartoma. The exact incidence of retinal astrocytic hamartoma (RAH) is not well known, but it is estimated at one case per 100000 births per year [1]. The astrocytic hamartoma is a neuroglial tissue and produces astrocytes within the optic nerve [2], and consequently it often appears within papillary region. Congenital...

The Point Ahead Angle Mechanism (PAAM) for ESA’s Laser Interferometer Space Antenna (LISA) mission will compensate the out-of-plane point-ahead angle between three satellites flying 5 million kilometres apart. The PAAM consists of a mirror supported by flexures allowing the mirror to rotate with a maximum stroke of ±1 mrad. The mirror is actuated in 0.14 μrad steps by two redundant linear Piezo...

This paper presents a micro XY stage that employs electrostatic comb-drive actuators and achieves a bi-directional displacement range greater than 225 μm per motion axis. The proposed XY stage design comprises four rigid stages (ground, motion stage, and two intermediate stages) interconnected via flexure modules. The motion stage, which has two translational degrees of freedom, is connected to...

radicular cysts arising from deciduous teeth are rare. this report presents a case of radicular cyst associated with a primary molar following pulp therapy and discusses the relationship between pulp therapy and the rapid growth of the cyst. the treatment consisted of enucleation of the cyst sac and extraction of the involved primary teeth and 20 months follow up of the patient. early diagnosis...

Recently evidence has accumulated that there are various interactions between the different levels of the central reticular core of the brain stem. (DELL, BONVALLET and HUGELIN 1961 ; MORUZZI 1964). The present study was initiated to know how the mesencephalic reticular formation (MRF) acts to regulate activity of the pontine reticular formation (PRF). This MRF-originated, descending effect con...

neuromelanin (nm) pigment accumulates with age in catecholaminergic neurons in man, and the ventral substantia nigra dopaminergic neurons that are the most vulnerable to degeneration in parkinson's disease (pd) contain the greatest amount of this pigment. in vitro data indicate that nm pigment is formed from the excess cytosolic catecholamine that is not accumulated into synaptic vesicles via t...

The influence of polymeric dispersants containing different functional groups on TiO2 pigment particle suspension was investigated at pH 6.0 and 9.5, using rheology and particle size data. The dispersants chosen were polyacrylic acid and modified polyacrylamides including homo and copolymers modified with carboxylate and/or hydroxyl groups. The pigment suspension was strongly affected by both p...

Flexure mechanisms are a designer’s delight. Except for the limits of elasticity, flexures present few other boundaries as far as applications are concerned. Flexures have been used as bearings to provide smooth and guided motion. For example in precision motion stages; as springs to provide preload, for example in the brushes of a DC motor or a camera lens cap etc. Flexural joints are widely u...

This paper presents a micro XY stage that employs electrostatic comb-drive actuators and achieves a bi-directional displacement range greater than 225 μm per motion axis. The proposed XY stage design comprises four rigid stages (ground, motion stage, and two intermediate stages) interconnected via flexure modules. The motion stage, which has two translational degrees of freedom, is connected to...