The photosynthetic reaction is commonly summarized by the following equation: 6 C02+ 6 H20 = C6H1206+6 02 The organic material formed has been commonly assumed to be glucose or some other carbohydrate. This equation is based principally on three types of facts: (a), the preponderance of carbohydrate material in plants, and the observed rapid increase in carbohydrates on illumination of green pl...

In this paper an attempt is made to formulate criteria for the accuracy in the delivery of absorbed dose to a patient during photon or neutron therapy. These requirements are mainly based on the relative steepness of dose-effect curves for local tumour control and normal tissue damage. A review of these dose-effect curves after photon irradiation shows a great variety in steepness; the curves f...

UNLABELLED Dosimetric calculations are performed with an increasing frequency before or after treatment in targeted radionuclide therapy, as well as for radiation protection purposes in diagnostic nuclear medicine. According to the MIRD committee formalism, the mean absorbed dose to a target is given by the product of the cumulated activity and a dose-conversion factor, known as the S factor. S...

We describe lasing of a thulium-doped polarizing photonic crystal fiber. A 4 m long fiber with 50 μm diameter core, 250 μm diameter cladding, and d/Λ ratio of 0.18 was pumped with a 793 nm diode and produced a polarized output with a polarization extinction ratio (PER) of 15 dB and an M(2) of <1.15. An intracavity polarizer and half-wave plate minimally increased the PER to 16 dB. The output po...

background: this study assessed the clinical usefulness of the solid phantom, which may compensate for the disadvantages of the water phantom, by comparing the radiological doses between the two depending on their depths. materials and methods: the experimental equipment used was a linear accelerator for medical use, water phantom, solid phantom, farmer type ion chamber and electrometer. the di...

Detector systems using plastic scintillators can provide instantaneous measurements with high spatial resolution in many applications including small field and high dose gradient field applications. Energy independence and water equivalence are important dosimetric properties that determine whether a detector will be useful in a clinical setting. Using Monte Carlo simulations, we calculated the...

Nonsaturating light at 600 or 436 nanometers was used to excite specifically phycocyanin or chlorophyll a, respectively, both of which participate in light capture in photosystem II of Cyanidium caldarium. The ratio of absorption of light by phycocyanin to chlorophyll in photosystem II in this organism is >20 at 600 nanometers and </=0.2 at 436 nanometers.The distribution of the absorbed light ...