Exposure to ultraviolet (UV) radiation may cause the significant degradation of many materials. UV radiation causes photooxidative degradation which results in breaking of the polymer chains, produces free radical and reduces the molecular weight, causing deterioration of mechanical properties and leading to useless materials, after an unpredictable time. Polystyrene (PS), one of the most impor...

In some experiments and applications there is need for large-area photosensitive detectors to operate at cryogenic temperatures. Nowadays, vacuum PMs are usually used for this purpose. We have developed special designs of planar photosensitive gaseous detectors able to operate at cryogenic temperatures. Such detectors are much cheaper PMs and are almost insensitive to magnetic fields. Results o...

Virtuality is the property of computer system with the potential for enabling a virtual system (operating inside the computer) to become a real system by encouraging the real world to behave according to the template dictated by the virtual system. Virtual phenomena like virtual memory, network switching, virtual teams, virtual reality and virtual organization may change our way to work and per...

It is well known that the renin-angiotensin system (RAS) is involved in the control of blood pressure. Recently, all or part of the components concerning the RAS have been reported to be synthesized and secreted outside of classical organs or tissues, at sites including the brain, pituitary and pineal glands, eye, heart, adrenal gland, testes, ovary, placenta, and coagulating glands. The functi...

Pneurnonectomy has recently made a rernarkable development on account of the discovery of penicillin and streptomycin. When compared with it open drainage treatment has much fallen behind in its development, although it belongs to the same category as pneumonectomy, both being direct rnethods of treatment. This may due to various reasons, but the most basic one rnay be that the technique of cav...

Introduction: Physicians have to visit, diagnose and refer patients with genetic disorders, so they need to be familiar with the basics and indications of genetic tests. In other words, they should have effective theoretical and practical knowledge about medical genetics before they do their job. Medical genetics courses at Medical Universities of Iran are generally presented as a theoretical s...