Immature embryo- derived calli from the wheat accession 1908 were irradiated with gamma rays at 2.58×10^-1C/kg. The frequency of somaclonal variation in the second generation (C₂R₂) went up to 25%, being about four times as high as that of the non- irradiated counterpart (R₂). From the calli- irradiated regenerant's progeny, one elite line with high yield potential, early maturity, resistance to both scab disease and lodging was isolated and officially registered as a new variety named Hezu 8.

The present work has dealt extensively and systematically with the fading characteristics of polystyrene-alanine dosimeters irradiated at different dose rates and total doses under various temperatures (10—70°C) and stored a period of time in different conditions (5, 25, room temperature, 40°C). Detail investigation on this effect in practical irradiation condition is very important. Because it is difficult to correct this effect using correction coefficients so far. So the temperature coefficients and fading rates have been given along with a lot of experimental data to try to make approximation of radical formation or decay behavior.

The K-shell ionization probability P_K was measured as a function of E_p across the strong resonance ⁵⁶Fe(p,p)⁵⁶Fe at 2.522 MeV and about 50% variation was observed. For a large ratio of the K-shell binding energy to the total width of the nuclear resonance, U_K/Γ≥5, the present experimental result is still in good agreement with theoretical calculation based on Blair and Anholt's formula.

Positron lifetime was measured on crystalline indium phosphide by a high resolution time spectrometer. By trapping model positron lifetime in bulk InP was estimated at 231.5 ± 1.5 ps which was carefully compared with the experimental and the theoretical values known from the literature.

Enriched uranium(UO₂F₂) accumulated in organism could cause chromosome aberrations in somatic cells, its rates on bone marrow cells were elevated when the dose of ²³⁵UO₂F₂ was increased. Among the types of induced aberrations, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Chromatid delation and chromatid exchange were induced in peripheral blood lymphocytes. The important type of aberrations in spermatogonia was break. For primary spermatocytes the most significant aberration was multivalents which resulted either from chromatid interchanges or reciprocal translocations. ²³⁵UO₂F₂ could result in DNA breakage in germ cells. The sensitivity of germ cells at various stages to ²³⁵UO₂F₂. was different. At 12 d after exposure the amount of sperm DNA eluted reached the peak. When the treating time was fixed, elution of sperm DNA from treated animals increased with the increasing doses. ²³⁵UO₂F₂ could also result in sperm abnormalities. Especially at 13 to 36 d after treatment the rates of sperm abnormalities were significantly elevated.

In order to explore an "anomalous" conduction phenomenon in the system Zn_(1-x)FeCrO₄Ni_x which was investigated with Mossbauer spectra, X-rays diffraction, Infrared spectra and other methods. The results show that the conductivity anomaly is not an intrinsic behavior but arises from the moisture-adsorption. Their native conduction is similar to that of semiconductors, obeying the relationship σ= σ_∞ exp (E_a/KT). All samples crystallize in cubic symmetry and their lattice parameters increase with x. The cation distribution is ( Zn_(1-x)Fe_x) [Fe_(1-x)Ni_xCr]O₄. No phase change occurs in the temperature range from 283 to 423 K.

Thirty patients in coma state underwent dynamic SPECT with ¹³³Xe, a validated technique for the quantitation of CBF by SPECT, using a new brain dedicated tomograph: CERTO-96. CMRO₂ was computed by multiplying the mean CBF by AVDO₂ according to the Fick's principle. The mean values of CBF, AVDO₂ and CMRO₂ in patients with good outcome were significantly different from those with worse outcome. On the basis of the best "discriminant threshold", CBF and AVDO₂ demonstrated an intermediate accuracy in separating the two groups, while CMRO₂ showed a satisfactory accuracy.

Italian money has been investigated by Mössbauer spectroscopy. The results indicated that the spectrum of a 10000 lire bank-note consisted of three magnetic sextets and two quadrupole doublets, the spectrum of a 50000 lire note consisted of two Zeeman sextets, but in the "false" money there are two quadrupole doublets only.

γ-radiation damage study of photodevice and its substrate shows that γ-radiation makes the light current, current amplification factor and respond time of devices decreased, dark current increased, but junction capacitance unchanged basicly. The resistivity of substrate was slowly increased. The analysis of positron annihilation lifetime spectra demonstrated that the second lifetime component τ₂ was reduced, but the corresponding intensity I₂ raised. Those indicate the macroscopic and microscopic changes in substrate after γ-irradiation.

A very simple basic equation for the comparator technique is derived for the determination of ¹³C/¹²C ratio in biological samples by proton induced gamma- ray emission. On the basis of this treatments a new series of experiments has been made at a 2×1.7 tandem accelerator that proved conclusion about the method.

The synthesis of 3, 4-dihydroxy-6-bromo-phenyl-L-alanine (6-Br-L-dopa), preparation of 3,4-dihydroxy-6-[⁷⁷Br] bromo-phenyl-L-alanine(6-⁷⁷Br-bromo-L-dopa) and its distribution study in mouse brain are described. The radiochemical yield and radiochemical purity of 6-⁷⁷Br-bromo-L-dopa were 8.5% and 93%, respectively. Its distribution in mouse brain after one hour injection indicates that it does pass blood brain barrier. The ratio of uptake in striatum to that in cerebellum was 2.45±0.12. The results appeared that 6-⁷⁷Br-bromo-L-dopa could be used as brain tracer for visualizing dopamine-containing brain structures by using single photon tomography.

The preparation of the human hair reference material and the steps taken to confirm its homogeneity and stability as well as its certification are described. Certified values for 17 elements, which are of importance for human health, and reference values for the other 13 elements are provided for this material.

Red and white guavas were treated with wax emulsion or irradiation (0.25—2.0 kGy) and kept for 12 days at room temperature. Initiation of rot attack occurred after 3 days which increased significantly during further storage. In the waxed fruits rottage, weight loss and vitamin loss were significantly less than controls and irradiated ones. Sensory scores decreased with storage time and they ranged 3.7—4.5, 2.1—3.9 and 2.3—2.7 in waxed, radiated and untreated controls respectively, after 12 days storage. Waxing was found to increase the shelf life of this fruit for 3—4 d while irradiation exhibited no beneficial effects.