Epidemiological survey of workers exposed to inorganic germanium compounds

Tin and germanium monochalcogenide IV-VI semiconductor nanocrystals for use in solar cells

The incorporation of colloidal semiconductor nanocrystals into the photoabsorbant material of photovoltaic devices may reduce the production costs of solar cells since nanocrystals can be readily synthesized on a large scale and are solution processable. While the lead chalcogenide IV-VI nanocrystals have been widely studied in a variety of photovoltaic devices, concerns over the toxicity of lead have motivated the exploration of less toxic materials. This has led to the exploration of tin and germanium monochalcogenide IV-VI semiconductors, both of which are made up of earth abundant elements and possess properties similar to the lead chalcogenides. This feature article highlights recent efforts made towards achieving synthetic control over nanocrystal size and morphology of the non-lead containing IV-VI monochalcogenides (i.e., SnS, SnSe, SnTe, GeS and GeSe) and their application toward photovoltaic devices.

Functional changes on ascending auditory pathway in rats caused by germanium dioxide exposure: an electrophysiological study

The semiconductor element, germanium (Ge), is essential for the manufacture of modern integrated circuits. Because of its anti-tumor and immunomodulative effects, Ge-containing compounds are also used as health-promoting ingredients in food. However, some histological studies have shown the toxic effects of Ge-containing compounds on various organs, including the central nervous system. Even now, the effect of germanium on auditory system function is not completely clear. To clarify this question, brainstem auditory evoked potentials (BAEPs) were applied to examine the effect of germanium dioxide (GeO(2)) on the ascending auditory pathway. Since the voltage-gated sodium channel is important to neuron activation and nerve conduction, the effect of GeO(2) on voltage-gated sodium channels was also examined. The result revealed GeO(2) elevated the BAEPs threshold dose-dependently. GeO(2) also prolonged latencies and interpeak latencies (IPLs) of BAEPs, but the amplitudes of suprathreshold intensities (90dB) did not show any obvious change. In addition, the results of whole cell patch clamp studies indicated GeO(2) reduced inward sodium current. These results suggest the toxic effect of GeO(2) on the conduction of the auditory system, and that inhibitory effect of GeO(2) on the voltage-gated sodium channels might play a role in GeO(2)-induced abnormal hearing loss.