Search results for " dose"

Toxicokinetics, toxicity and lethal body residues of two chlorophenols in the oligochaete worm, Lumbriculus variegatus, in different sediments

2003

Bioavailability, toxicokinetics and toxicity (LC(50)) of water- and sediment-associated 2,4,5-trichlorophenol (2,4,5-TCP) and pentachlorophenol (PCP) were measured in Lumbriculus variegatus Müller in a set of experiments. The critical body residue approach was applied by measuring also the lethal body residues (LBR(50)). Freshwater and three different sediments with various sediment organic carbon (SOC) concentrations were used as exposure media. SOC decreased the bioavailability of both chlorophenols, and the uptake rates decreased by 81% and 91% for 2,4,5-TCP and PCP, respectively, in the sediment with a SOC of 6.9% compared to those in sediment with a SOC of 0.5%. SOC appeared to be an i…

Environmental Gamma Radiation Measurements on the Island of Pantelleria

1992

The population exposure to those living on the island of Pantelleria, Italy, was estimated by measuring the natural gamma background. Gamma spectra of natural rocks and measurements of absorbed dose in air were taken. A correlation was found between the mean gamma exposure rate and the mean values of natural radionuclide concentrations in the investigated rocks.

The 15-Country Collaborative Study of Cancer Risk Among Radiation Workers in the Nuclear Industry: design, epidemiological methods and descriptive re…

2007

International audience; Radiation protection standards are based mainly on risk estimates from studies of atomic bomb survivors in Japan. The validity of extrapolations from the relatively high-dose acute exposures in this population to the low-dose, protracted or fractionated environmental and occupational exposures of primary public health concern has long been the subject of controversy. A collaborative retrospective cohort study was conducted to provide direct estimates of cancer risk after low-dose protracted exposures. The study included nearly 600,000 workers employed in 154 facilities in 15 countries. This paper describes the design, methods and results of descriptive analyses of th…

Changes in biochemical composition of gills, hepatopancreas and muscle of the red crayfish Procambarus clarkii (Girard) after sublethal exposure to m…

1992

Abstract 1. 1. The changes in the biochemical composition of gills, hepatopancreas and muscle after exposure to 0.25 mg Hg/l were studied in Procambarus clarkii . 2. 2. Sublethal exposure to mercury in P. clarkii resulted in significant decreases in protein concentration and caloric concentration in gills over the 96 hr period. Glycogen/lipid and glycogen/protein ratios increased after 48 and 96 hr of mercury exposure. 3. 3. Lipid and caloric concentration in the hepatopancreas were significantly lower in 96 hr mercury exposed group. 4. 4. Glycogen concentration in muscle was depleted as consequence of 96 hr mercury exposure.

Acute toxicity and oxygen consumption in the gills of Procambarus clarkii in relation to chlorpyrifos exposure.

1992

A comparative epizootiologic study of the two fish-pathogenic serovars ofVibrio vulnificusbiotype 2

2010

Vibrio vulnificus biotype 2 is subdivided into two main serovars, serovar E, able to infect fish and humans, and serovar A, only virulent for fish. Serovar E emerged in 1976 as the causative agent of a haemorrhagic septicaemia (warm-water vibriosis) affecting eels cultured in brackish water. Serovar A emerged in 2000 in freshwater-cultured eels vaccinated against serovar E, causing warm-water vibriosis with fish showing a haemorrhagic intestine as the main differential sign. The aim of the present work was to compare the disease caused by both serovars in terms of transmission routes, portals of entry and host range. Results of bath, patch-contact and oral-anal challenges demonstrated that …

Effects of cadmium on the biochemical composition of the freshwater crayfishProcambarus clarkii (Girard, 1852)

1991

Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when…

Pr�vention thromboembolischer Komplikationen in der Unfallchirurgie durch Dosisanpassung von niedermolekularem Heparin anhand TAT- und D-Dimer-Werten

2003

Bei unfallchirurgischen Patienten tritt in bis zu 40% eine tiefe Beinvenenthrombose auf. Das individuelle Risiko kann kaum kalkuliert werden. 518 unfallchirurgische Patienten mit Prophylaxe durch eine tagliche Einzeldosis eines niedermolekularen Heparins (NMH) wurden praoperativ und bis zu 10 Tage postoperativ in einer prospektiven Untersuchung beobachtet. Sie wurden in 2 Gruppen unterteilt: Gruppe I mit Huft- und Oberschenkeloperationen sowie Kniegelenkprothesen und Gruppe II mit Knie- und Unterschenkeloperationen. Bestimmt wurden Thrombin-Antithrombin-Komplex und D-Dimer. Eine 2. Dosis NMH wurde bei Uberschreiten des D-Dimer-Cut-off-Wertes verabreicht. Bei sonographischem Verdacht auf ein…

Kinetics of Anti-Hepatitis B Surface Antigen Titers in Nurse Students after a Two-Year Follow-Up

2020

Infection caused by hepatitis B virus (HBV) can be prevented through a safe and effective vaccine. This study analysed the kinetics of serum antibodies against hepatitis B surface antigen (HBsAg) (anti-HBs) titers in relation to previous vaccine boosters in Italian nursing students who were followed up for two years. Serum anti-HBs titers were evaluated at the first visit, after vaccine booster (if required) and at visit after two years. Overall, 483 students (mean age = 21.7 years

A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate Ir-192 brachytherapy

2017

PurposeA joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and comparisons with model-based dose calculation algorithms (MBDCAs). Its main goal is to facilitate a smooth transition from the AAPM Task Group No. 43 (TG-43) dose calculation formalism, widely being used in clinical practice for brachytherapy, to the one proposed by Task Group No. 186 (TG-186) for MBDCAs. To do so, in this work a hypothetical, generic high-dose rate (HDR) Ir-19…