Electrical properties of multi p-n junction devices

The electrical properties of multi p-n junction devices are analyzed. It is found that this type of device possesses bistable characteristics similar to that of a Shockley diode and thus provides an alternative realization of devices for switching applications. The inherently greater current gains involved in the operations of such a device yield in principle higher breakover voltages and higher holding currents. Furthermore, the incorporation of heterostructures in this device introduces a new degree of freedom in tailoring their switching characteristics. Multi p-n heterojunction devices operating as SCR lasers were fabricated, and the experimental results are presented

Q-switched ruby laser alloying of Ohmic contacts on gallium arsenide epilayers

Ohmic contacts of AuGe have been produced on GaAs epilayers by laser alloying. The contacts possess morphological and electrical properties which are superior to those formed by conventional alloying

Recent developments in monolithic integration of InGaAsP/InP optoelectronic devices

Monolithically integrated optoelectronic circuits combine optical devices such as light sources (injection lasers and light emitting diodes) and optical detectors with solid-state semiconductor devices such as field effect transistors, bipolar transistors, and others on a single semiconductor crystal. Here we review some of the integrated circuits that have been realized and discuss the laser structures suited for integration with emphasis on the InGaAsP/InP material system. Some results of high frequency modulation and performance of integrated devices are discussed

Inula Viscosa Extract Inhibits Growth of Colorectal Cancer Cells in vitro and in vivo Through Induction of Apoptosis

Colorectal cancer (CRC) is the second most common cancer in females and the third in males worldwide. Conventional therapy of CRC is limited by severe side effects and by the development of resistance. Therefore, additional therapies are needed in order to combat the problem of selectivity and drug resistance in CRC patients. Inula viscosa (IV) is a well-known medicinal perennial herb in traditional medicine. It is used for different therapeutic purposes, such as; topical anti-inflammatic, diuretic, hemostatic, antiseptic, antiphlogistic, and in the treatment of diabetes. Several studies attempted to reveal the anti-cancer activity of different extracts prepared by different organic solvents from different parts of the IV plant. The aim of the present study is to examine the potential beneficial effects of IV leaf aqueous extract on the growth of colon cancer cells in vitro and in vivo. The results indicated that exposure of colorectal cancer cells to IV extract, significantly reduced cell viability in a dose and time dependent manner. Moreover, treatment of cells with 300 μg/ml of IV extract induced apoptosis, as it was detected by Annexin V/FITC/PI, TUNEL assay, and the activation of caspases. In vivo studies revealed that treatment with 150 or 300 mg/kg IV extract inhibited tumor growth in mice transplanted with MC38 cells. Tumors' weight and volume were significantly (P < 0.001) reduced when compared to untreated-control group. Staining of the paraffin section of tumors revealed that IV treatment inhibited cell proliferation and induced apoptosis. Additionally, no side effects such as; weight loss, behavior changes, ruffled fur or changes in kidney, and liver functions were observed. These results may indicate that active doses of IV extract are not toxic. Further studies are needed in order to identify the structure of the active compounds. Results from this study may contribute to the development of new and efficient strategies for treatment of human colon cancer

Mode stabilization mechanism of buried-waveguide lasers with lateral diffused junctions

The mode stabilization behavior of the buried active waveguide with lateral diffused junction is theoretically investigated. The study shows that for an active waveguide of width around 5 μm with a lateral diffused junction in the middle, the single fundamental transverse mode is preferred as the injection level is raised. The theoretical results are found to be in good agreement with experimental results observed in the groove transverse junction InGaAsP/InP laser