Photoaeoustic spectroscopy (PAS) has become a valuable technique for detection of weak signals. The photoacoustic effect, on which PAS is based, was discovered as early as 1880 by A. G. Bell, but for a long period afterward, it did not find widespread application. In the 1970s, it was revived primarily because of technological advances made during the preceding two decades. One of these important achievements was the development of laser. Compared to incoherent sources of radiation, la...
An 8-year-old Chinese girl who was noted to have feeding difficulty and poor weight gain since her infancy. Her motor development was delayed with sitting at 1-year-old and walking independently at 2-year-old. She visited our OPD when she was 8. Physically, she was thin and slender. Her height and weight were below the 10th and 3rd percentile. Her face was elongated with high arched palate. Neurologically, she had waddling gate with marked proximal muscle weakness. Her cranial nerves and sensation remained intact. Laboratory tests including blood routine, liver function, renal function, electrolytes, NCV and cardiac echo all were within normal limits. The EMG showed myopathic pattern. A fresh-frozen muscle biopsy stained with the modified Gomori trichrome, processed by histochemistry and electronmicroscopic examination showed typical nemaline rods with predominance of type 1 muscle fibers. She was then diagnosed to have nemaline myopathy.