Mya and Ciona are two animals which are sensitive to light, and which respond to it by a vigorous retraction of the siphons. As a result of previous work~ it is known that the receptor mechanism underlying this sensitivity to light is composed of two associated processes. The first of these takes place during the necessary exposure to light. I t follows the Bunsen-Roscoe law, and is practically...

A new molybdenum porphycene complex, which is a new complex having oxo and chloro groups at the axial positions, was successfully synthesized. This chloro(oxo)molybdenum(v) complex, [Mo(V)(OEPc)(O)Cl] (1) has strong absorption bands in the visible region attributed to the properties of the porphycene and is very attractive from a photochemical viewpoint. This complex was readily reduced from Mo...

Organic synthesis using light as reagent and producing complex molecules from simple starting materials is realized in exemplary fashion in natural photosynthesis. Mankind still struggles for an efficient molecular system that mimics this natural process. In order to harvest light energy and to transform it into chemical energy, photochemical reactions must be studied and optimized for syntheti...

AIM To assess the retinal phototoxicity hazards of and to provide safety margins for endoillumination during vitrectomy. METHODS The absolute power and spectral distribution from various light sources and filter combinations that are commercially available for vitreous surgery were measured. The maximal exposure times based on the ICNIRP safety guidelines for photochemical and thermal injury ...

Light is one of most important factors to plants because it is necessary for photosynthesis. In this study, physiological and gene expression analyses under different light intensities were performed in the seedlings of rubber tree (Hevea brasiliensis) clone GT1. When light intensity increased from 20 to 1000 µmol m(-2) s(-1), there was no effect on the maximal quantum yield of photosystem II (...

Mya and Ciona are two animals which are sensitive to light, and which respond to it by a vigorous retraction of the siphons. As a result of previous work~ it is known that the receptor mechanism underlying this sensitivity to light is composed of two associated processes. The first of these takes place during the necessary exposure to light. I t follows the Bunsen-Roscoe law, and is practically...

low level laser therapy (lllt) uses a light source that generates extremely pure light, of a single wavelength1. the effect is not thermal, but rather related to photochemical reactions in the cells. lllt was introduced as an alternative non-invasive treatment for oa about 10 years ago, but its effectiveness is still controversial2. a cochrane review of lllt in osteoarthritis included five tria...

OBJECTIVE Erythemagenic (295-305 nm) ultraviolet-B (UVB) radiation is toxic to patients with systemic lupus erythematosus (SLE). Cool white fluorescent lamp emissions produce a similar toxicity even though the UVB radiation emitted is primarily at the relatively non-erythemagenic wavelength of 313 nm. The purpose of this study was to determine if fluorescent light, presumably acting predominant...

In a conventional photocatalytic or photochemical process, either a photocatalyst or a molecule is excited by irradiation light that has energy greater than the forbidden band (i.e., the band gap) of the semiconductor or the transition energy of an excited state of the molecule, respectively, for a reaction to occur. However, in this work, we found that a considerable amount of H2 can be genera...

low level lasers, cold or soft lasers: these lasers do not produce thermal effects on tissues and induce photoreactions in cellsthrough light stimulation which is called photobiostimulation. power of these lasers is usually under 250mw. the main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. the most important fact...