[en] Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ∼106 cm/sec at the driving frequency of ∼26 kHz, and drift upward through the ball at ∼1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.

[en] Measurements were made of the motion of the filamentary structures in a plasma ball using high-speed cameras and other optical detectors. These filaments traverse the ball radially at ∼10⁶ cm/s at the driving frequency of ∼26 kHz and drift upward through the ball at ∼1 cm/s. The number of filaments and their radial speed increase approximately linearly with the applied voltage above some threshold. A custom plasma ball was constructed to observe the effects of varying gas pressure, gas species, and electrode properties on the filament structures.

[en] The monoclonal antibody (AcMo) IOR-CEA1 is considered a tumor marker for principally colon and rectal cancer. With the aid of nuclear techniques the molecule was labeled with radioisotope ¹³¹I, produced at IPEN Radioisotope Production Plant. Initially, the monoclonal antibody was labeled with ¹³¹I according to Chloramine T techniques, as described in the 'Guide of Radioidonation of Amersham Life Science'. A satisfactory result was not obtained, as the antibody could not be bounded to ¹³¹I thus, modifications were made to the technique, increasing incubation time and concentration of the oxidant agent (Chloramine T). As a result, in the radiochemical purity (PQR) a percentage average of the 97,57% ± 1,53. Stability of the labeled molecule was also asses, resulting in a molecule of PQR > 90%. This value was maintained even on the sixth day after being labeled. (author)

[en] A gamma ray scanning system was developed, aiming to identify process failures in industrial columns. Two scintillator detectors: CsI(Tl) and NaI(Tl) were used for comparison. This system was tested in an industrial column for water treatment (6.5 m diameter and 40 m height). The source detector system consists of: (1) ⁶⁰ Co radioactive sealed source in a panoramic lead irradiator, (2) a scintillator detector coupled to a ratemeter / analyzer and (3) a mobile system. A dedicated computer with software for a data processing was used for recording in appropriate intervals and a profile of the instantaneous operation state was obtained by plotting the detector response against the column elevation. Based on the gamma ray absorption behavior of the inside medium, the density profiles of the columns were obtained. The thickness and the relative tray position column could then be clearly identified. Both, the NaI(Tl) and the CsI(Tl) detectors showed good properties for gamma scanning applications. (Author)

[en] This work, concerning the marking of the thyroid hormone 3'3', 5- triiodothyronine (T3) with I-125 for the obtaining of the thyroxine I-125 T4 by the chloramine T method, consists of labelling, purification and storage of the I-125 T4. The mechanism of reaction proposed from the T3 for its labelling with I-125 is carried out through the isotopic interchange, that is a balance reaction, while the I-125 T4 obtaining is performed through an aromatic electrophilic substitution (SEA) which is irreversible. Two modifications were carried out with regard to the literature: first, the labelling time of 1 minute was extended to 2 minutes and; second, the use of other molar relations of T3 and I-125. All the results obtained are based on a total of 4 labelling

[en] To establish radioimmunological procedures in order to detect the surface antigen (HBsAg) and the surface antibody (anti-HBs) of viral hepatitis B. Iodine-125 was incorporated into the antigen or monoclonal antibody with the employment of the Chloramine T method. Theoretical and experimental yield of labeling and specific activities were calculated for labeled molecules. In order to obtain the solid phase component, the surface antigen or surface antibody maintained in a buffer solution of carbonate-bicarbonate and posterior incubation with newborn calf serum at 10 percent, was coated to polystyrene beads. International reference standards and internal negative and positive quality control samples were employed during radioimmunoassays

[en] Using the MIRD formalism, and the Cristy-Eckeman/Segars anthropomorphic representations, the study estimates the absorbed dose in the thyroid of newborns, for these representations. Radiopharmaceuticals (RFM) ¹³¹I/¹²³I (iodides) and ^99mTc (pertechnetate) are used during their diagnostic procedures. The dose results will allow exploring the dosimetric impact generated by the use of these RFM as well as their representations. The study indicates:The higher dose absorbed by the thyroid gland in newborn patients due to the compounds ¹³¹I/¹²³I (iodide) and ^99mTc(pertechnetate), calculated in the anthropomorphic representations of Cristy-Eckerman and Segars, is mainly due to their self-dose, generated by the electrons released by these compounds.The relative difference in total dose to the newborn thyroid gland using the Cristy-Eckerman and Segars anthropomorphic representations for the compounds ¹³¹I/¹²³I (iodide) and ^99mTc (pertechnetate) was 0.72%, 1.82%, and 1.33%, respectively. Regardless of the RFM selected, replacement of Cristy-Eckerman phantoms by Segars phantoms does not reflect significant changes in the estimated absorbed dose to the newborn thyroid.Regardless of the Cristy-Eckerman or Segars anthropomorphic representation, the lowest dose to a new-born's thyroid is obtained when using ^99mTc (pertechnetate). The residence times for this RFM contribute to that dose. (author)

[en] To determine the prevalence of the HBsAg, anti-HBs, anti-HBc, HBeAg and anti-HBe to estimate virus infection of the hepatitis B in children from twelve communities from the Luricocha district in the Huanta province, Ayacucho

[en] Detection of hepatitis C virus in sera samples by specific amplification of the 5' non-coding conserved region of HCV. 8 anti-HCV EIAs positive blood donors sera were evaluated, 5 from the Hospital Nacional Cayetano Heredia (HNCH) and 3 from the Instituto de Enfermedades Neoplasicas (INEN). RNA was extracted from sera using trizol and reverse transcripted with primer 209. Nested PCR amplification was carried out with primers 209-939 in a first round and 211-940 primers during the second round of amplification. Visualization of amplification products was done after electrophoresis in 2% agarose gel and ethidium bromide staining

[en] Highlights: • DTPA, DMSA, and MAG3 compounds labeled with ^99mTc are used for renal studies. • MIRD methodology is used to calculate the absorbed doses in kidneys and other organs. • The SAF for adult and child, male and female, phantoms (Stabin/Segars) are used in MIRD. • The absorbed doses due to ^99mTc compounds in an early pregnant patient were calculated. • The impact on the absorbed dose of using Stabin or Segars representations was determined. MIRD method with the Stabin/Segars anthropomorphic representations were used to calculate the absorbed doses in kidneys and uterine wall of an early-stage pregnant woman when ^99mTc (DTPA), ^99mTc (DMSA) and ^99mTc (MAG3) are used for renal studies. Stabin and Segars anatomical representations are phantoms that are used in Monte Carlo calculations to determine the SAF, that with the pharmaceutical residence time are used to calculate the absorbed dose, from source organs, on target organs. Concerns about the impact on the absorbed dose due to the use of the three ^99mTc-based compounds as well as the use of different phantoms were here treated for the case of a female at early pregnant state. The lowest absorbed dose in the kidneys was obtained with ^99mTc (MAG3), and the relative difference of using Stabin and Segars anthropomorphic representations was 2.5%. For bladder and rest of organs the relative difference 14.63%. The lowest absorbed dose by uterine wall was obtained with ^99mTc(DMSA), however the relative difference of using Stabin and Segars anthropomorphic representations was 12%.