Search results for "intensity"
showing 10 items of 1091 documents
Safety and efficacy of intensity-modulated radiotherapy in the management of spermatic cord sarcoma.
2017
International audience; Purpose. - Spermatic cord sarcoma is a rare disease, which management remains controversial due to the lack of guidelines. The standard therapeutic approach is surgical: wide soft-tissue resection with radical inguinal orchidectomy, The diagnosis is made during the analysis of the specimen. The high rate of local recurrence indicates adjuvant radiotherapy of the tumor bed. The aim of this series is to determine the efficacy and safety of postoperative intensity-modulated radiotherapy for spermatic cord sarcomas. Patients and methods. - Our series included five consecutive cases of spermatic cord sarcoma treated between 2011 and 2014. The indications for radiotherapy …
Light intensity preference of juvenile pikeperch Sander lucioperca (L.)
2006
Light intensity preference of the pikeperch was tested in 1-m2 tanks divided into four lateral compartments with a hole in the middle to allow the fish to move between compartments. Two experiments were carried out with both 0+ and 1+ pikeperch: one testing intensities from 25 to 300 lx and the other from 1 to 50 lx. Light preference was observed individually for 5 days at 8, 11, 14 and 17 h. On the first and fifth day, the preference was tested without differences in light intensity (control). In both experiments, both age groups showed preference for the lowest available light intensity. Preference for low light intensity in pikeperch may be related to innate activity and feeding behaviou…
Photocatalytic membrane reactors for degradation of organic pollutants in water
2001
Abstract Different flowsheets (batch and continuous) of photocatalytic membrane reactors, to be used for degradation of organic pollutants present in water, together to some experimental results, are reported. 4-Nitrophenol (4NP) was used as a probe polluting agent and titanium dioxide in suspension was the catalyst. The photodegradation tests in the batch system were carried out without membrane changing the characteristic variables of the process (light intensity, TiO 2 concentration, 4NP concentration, O 2 concentration, pH) to find their optimum values. The batch system consisted of a water jacket thermostatted and stirred beaker irradiated from above with a UV–Vis lamp (light intensity…
Autumnal shift from diurnal to nocturnal peaking feeding activity ofRutilus rutilusin boreal lake littoral zones
2008
The possibility that the feeding activity of roach Rutilus rutilus shows an autumnal shift towards hours of lower light intensity in shallow and illuminated habitats in temperate watercourses as a consequence of relatively increasing daytime predation risk was tested in a littoral zone of a large boreal lake using trapping experiments. Autumnal feeding activity of R. rutilus first showed a striking shift from day to twilight when water temperature fell from 20 to 10° C, and a low but steady night activity prevailed in late autumn, when temperature had fallen to 5° C and the length of the night had increased. The size of the captured littoral R. rutilus also increased throughout the autumn. …
Picosecond Time Resolved Analysis of the Fast and Slow Reversible Non-Photochemical Chlorophyll Fluorescence Quenching
1998
Photosystem II, which is a potential target of adverse effects of supersaturating light, is strongly dependent on a mechanism, which allows to switch over between efficient photochemical energy conversion at limiting light intensity and efficient photothermal energy conversion under strong light. The mechanisms for the thermal dissipation of light absorbed in excess are reflected by the socalled non-photochemical quenching of chlorophyll fluorescence (NPQ). Under excessive illumination two major components contribute to the overall NPQ which can be distinguished by their different kinetics of dark relaxation. The fast reversible component is supposed to be linked to the light-induced format…
New trends in photobiology
1993
Abstract At the beginning of our century few scientists paid attention to the phenomenon of inactivation of photosynthesis by high light intensities which was later called photoinhibition. In the period 1925–1950, the idea was established that photoinhibition is a reversible inactivation, determined by light intensity and exposure time, followed by irreversible damage of the photosynthetic apparatus. However, the absence of a uniform terminology demonstrates that photoinhibition was not completely perceived and understood. In 1956, B. Kok gave the first definition of photoinhibition as a photochemical inactivation of pigment complexes.
Light and Primary Production Shape Bacterial Activity and Community Composition of Aerobic Anoxygenic Phototrophic Bacteria in a Microcosm Experiment
2020
ABSTRACT Phytoplankton is a key component of aquatic microbial communities, and metabolic coupling between phytoplankton and bacteria determines the fate of dissolved organic carbon (DOC). Yet, the impact of primary production on bacterial activity and community composition remains largely unknown, as, for example, in the case of aerobic anoxygenic phototrophic (AAP) bacteria that utilize both phytoplankton-derived DOC and light as energy sources. Here, we studied how reduction of primary production in a natural freshwater community affects the bacterial community composition and its activity, focusing primarily on AAP bacteria. The bacterial respiration rate was the lowest when photosynthe…
On stress production in whispered Finnish
1987
We have compared sentence stress production in normal phonation and whisper in two native speakers of Finnish using acoustical analysis, esophageal pressure measurements and electromyography. The average peak values of the fundamental frequency, intensity, esophageal pressure and the EMG recordings from the thyroarytenoid and cricothyroid muscles were measured and their intercorrelations were calculated. In normal speech the cricothyroid activity and the subglottal pressure showed a significant correlation with the peak values of the acoustical indicators of stress for both subjects. The thyroarytenoid muscle showed a statistically significant correlation with the fundamental frequency for …
Stimuli-Responsive Polymeric Nanocarriers for Drug Delivery, Imaging, and Theragnosis.
2020
In the past few decades, polymeric nanocarriers have been recognized as promising tools and have gained attention from researchers for their potential to efficiently deliver bioactive compounds, including drugs, proteins, genes, nucleic acids, etc., in pharmaceutical and biomedical applications. Remarkably, these polymeric nanocarriers could be further modified as stimuli-responsive systems based on the mechanism of triggered release, i.e., response to a specific stimulus, either endogenous (pH, enzymes, temperature, redox values, hypoxia, glucose levels) or exogenous (light, magnetism, ultrasound, electrical pulses) for the effective biodistribution and controlled release of drugs or genes…
The Presence of White Matter Lesions Is Associated With the Fibrosis Severity of Nonalcoholic Fatty Liver Disease
2016
Abstract We tested whether nonalcoholic fatty liver disease (NAFLD) and/or its histological severity are associated with vascular white matter lesions (WML) in patients with biopsy-proven NAFLD and in non-NAFLD controls. Data were recorded in 79 consecutive biopsy-proven NAFLD, and in 82 controls with normal ALT and no history of chronic liver diseases, without ultrasonographic evidence of steatosis and liver stiffness value 45 years (OR 3.09, 95% CI: 1.06–9.06, P = 0.03; and OR 11.1, 95% CI: 1.14–108.7, P = 0.03), and F2–F4 fibrosis (OR 3.36, 95% CI: 1.29–8.73, P = 0.01; and OR 5.34, 95% CI: 1.40–20.3, P = 0.01) were independently associated with WML (mostly of mild grade) by multivariate…