Characteristics of DNA Comet, Photostimulated Luminescence, Thermoluminescence and Hydrocarbon in Perilla Seeds Exposed to Electron Beam

ABSTRACT: Detection characteristics of perilla seeds exposed to electron beam doses of 0 to 2 kGy were investigated. DNA comet assay, photostimulated luminescence (PSL) and thermoluminescence (TL) measurements, and hydrocarbon determinations by GC-MS were carried out. The irradiated samples showed comets with longer tails (152 ± 6 mm) than did nonirradiated samples (35 ± 11 mm). PSL values (photon counts) for the irradiated samples were more than 7865; whereas those of nonirradiated samples were less than 294. TL ratios (Glow 1/Glow 2) obtained from nonirradiated samples were less than 0.01 and above 0.48 from irradiated ones. The prominent radiation-induced hydrocarbons were 16:2, 16:3, 17:1, and 17:2, of which 16:2 was the most abundant.     

Characterization of fiber orientation in short fiber reinforced composites with an image processing technique

An experimental method is developed to measure the three-dimensional fiber orientation in short fiber reinforced composites by utilizing an image processing technique. The second order orientation tensor can be calculated with geometrical data that were obtained from two parallel planar cross-sections. The orientation state of individual fibers is determined from the geometry of the elliptical cross-sectional shape on the polished surface. The basic concept in determining the three-dimensional fiber orientation tensor is to slice the composite sample twice in the same direction within a small distance. The tensor is determined by using a digital image processing technique and a computational code which calculates the tensor from the geometrical characteristics obtained for the elliptical fiber cross-sections. Experiments are performed to measure the three-dimensional orientation tensor of composite specimens and good results are obtained by using the method proposed in this study Electronic Publication     

Immortalization of neuroendocrine pinealocytes from transgenic mice by targeted tumorigenesis using the tryptophan hydroxylase promoter

Tryptophan hydroxylase (TPH) is the first enzyme in both serotonin and melatonin biosynthesis in neuroendocrine cells of the pineal gland. The lack of immortalized neuroendocrine pineal cell lines has been a major obstacle to the study of the tissue-specific and circadian regulation of TPH gene expression in the pineal gland. Previously, we demonstrated that a 6.1 kb 5' upstream region of the mouse TPH gene directs the restricted expression of a lacZ reporter gene to the pineal gland and the raphe nuclei of transgenic mice. Therefore, to develop TPH-expressing pineal cell lines we first established transgenic mice carrying a construct consisting of 6.1 kb of 5' flanking region fused to the SV40 T-antigen. These animals developed highly invasive pineal tumors and died at 12-15 weeks of age. The pineal tumors obtained from the transgenic mice were utilized to establish the immortalized pinealocyte-derived cell lines. These cells express two marker enzymes, TPH and serotonin N-acetyltransferase (NAT). In pineal gland TPH and NAT expressions have been known to be regulated during circadian cycle. The two established cell lines therefore promise to be a valuable in vitro model system for the study of the rhythmic nature of the pineal function at molecular level in mammal.     

Modular synthesis of Petri nets for modeling flexible manufacturing systems

This paper proposes a modular Petri net synthesis method for modeling flexible manufacturing systems based on synchronization among control processes of the manufacturing resources (such as robots and machines). In the method, the target system is modeled in a bottom-up and uniform manner by first describing the system's control processes using strongly connected state machines (SCSMs) as the basic modules. Each SCSM may contain multiple tokens to represent resources from the same type such as spaces in a buffer. Next, the common transitions and common transition subnets of the modules are merged to represent their synchronization. The system model constructed is proven to be conservative and thus bounded. Moreover, a restricted class of merged nets is proven to be live and reversible. For general classes of merged nets, this paper shows theorems that easily calculateP-invariants of the final net without solving the linear system equations. TheseP-invariants can be used to help in verifying the model's qualitative properties such as liveness.     

Whole-body [18F]FDG PET in the management of metastatic brain tumours

BACKGROUND: To determine its roles in the diagnosis and the systemic evaluation of metastatic brain tumours, whole-body positron emission tomography (PET) using [18F]FDG was performed in 20 consecutive patients. METHODS: All patients were thought to be suffering or needing to be differentiated from metastatic brain tumours. Nine patients had multiple brain lesions; six were older and showed a rim-enhancing lesion with surrounding oedema; seven had homogeneously enhancing periventricular lesion(s) on computed tomography (CT) and/or magnetic resonance (MR) imaging, thought to be central nervous system lymphomas. Two patients had skull mass(es) and two patients had a solid mass suspected to be, respectively, a haemorrhagic metastasis and a metastatic malignant melanoma. All of them received whole-body [18F]FDG PET and conventional systemic work-up for metastasis in order to compare the results of the two methods. RESULTS: Metastatic brain tumours were diagnosed on whole-body [18F]FDG PET in eleven patients who had extracranial and intracranial hypermetabolic lesions. In nine of these, a conventional work-up also detected primary lesions which on whole-body [18F]FDG PET were seen to be hypermetabolic foci. Systemic lymph node metastases were detected by whole-body [18F]FDG PET only in two patients and histological diagnosis was possible by biopsy of lymph nodes rather than of brain lesions. In the remaining nine patients who had only intracranial hypermetabolic foci, histological diagnosis was made by craniotomy or stereotactic biopsy. It was confirmed that seven of nine patients were suffering from a primary brain tumour and two from metastatic carcinoma. None of the nine showed evidence of systemic cancer on conventional work-up. Histological diagnoses of the primary brain tumours were four cases of primary central nervous system lymphoma and one each of multifocal glioblastoma, Ewing's sarcoma, and cavernous angioma. Patients felt no discomfort during the whole-body [18F]FDG PET procedure and there were no complications. The false negative rate in [18F]FDG PET and in conventional work-up was 15.4% and 30.7% respectively. There were no false positives on either [18F]FDG PET or conventional work-up. CONCLUSION: It is suggested that whole-body [18F]FDG PET is a safe, reliable, and convenient method for the diagnosis and systemic evaluation of patients thought to be suffering or needing to be differentiated from a metastatic brain tumour.     

Optimal test-times for intermittent faults

Su et al. (1978) considered continuous and repetitive tests for a continuous-parameter Markov model with intermittent faults. Periodic tests for intermittent faults are scheduled at times k·T (k=1, 2,...). This paper presents a simple algorithm to compute the optimal time to minimize the mean cost until detection when the test model is imperfect. First an upper bound is found for the optimal time. Then a bisection-algorithm is used to minimize the cost of detecting faults for a system in which faults are intermittent and unpredictable. Using this algorithm, the solution of example 1 is better than that of Nakagawa and Yasui (1989) by at least 10%. This algorithm can be more useful than the Newton-Raphson method to locate an optimum because Newton-Raphson involves the first derivative whereas the bisection method does not     

Peripheral airways obstruction on high-resolution computed tomography in chronic severe asthma

BACKGROUND: An association between fats and colorectal carcinoma has been suggested, but the epidemiologic evidence by type of dietary fat is far less clear. Colorectal carcinoma rates have been relatively low in Mediterranean countries compared with most other Western countries, but the components of the Mediterranean diet responsible for this favorable pattern are unclear. METHODS: The relationship between various added (seasoning) fats and colorectal carcinoma risk was investigated using data from a case-control study conducted between January 1992 and June 1996 in six Italian areas. Cases were 1953 patients with incident, histologically confirmed colorectal carcinoma (1225 of the colon and 728 of the rectum) admitted to the major teaching and general hospitals in the study areas. Controls were 4154 subjects with no history of cancer who were admitted to hospitals in the same catchment areas for acute, nonneoplastic diseases unrelated to the the digestive tract and requiring no long term modifications of diet. Dietary habits were investigated using a validated food frequency questionnaire including 78 items. Lipid intake was estimated by taking into account the content of seasoning lipids in different dishes, the frequency of consumption and portion size of each dish, and individual fat intake patterns. RESULTS: The odds ratios (OR) for successive tertiles of olive oil intake, compared with the lowest one, were 0.87 (95% confidence interval [CI], 0.75-1.01) and 0.83 (95% CI, 0.70-0.99) (chi2trend = 4.49, P = 0.03) when colorectal carcinoma was analyzed as a whole, 0.82 (95% CI, 0.68-0.98) and 0.81 (95% CI, 0.66-0.99) (chi2trend = 4.05, P = 0.04) for colon carcinoma, and 0.96 (95% CI, 0.77-1.19) and 0.88 (95% CI, 0.66-1.12) for rectal carcinoma. For specific seed oils (including sunflower, maize, peanut, and soya), the OR for colorectal carcinoma was 0.91 in the highest tertile of intake, and the corresponding values were 1.01 for mixed seed oils and 0.93 for butter. None of these estimates was significantly different from the unity. Allowance for vegetable intake attenuated the apparent protection from olive oil consumption (OR, 0.94 for colon and 0.97 for rectum for the highest tertile), which still was apparent in younger subjects (OR, 0.82 for colon and 0.69 for rectum). CONCLUSIONS: In this study, seasoning fats did not appear to increase the risk of colorectal carcinoma, and there was little evidence for a differential effect by fat type. If such a differential effect exists, it is minor and could favor olive oil.     

Survival of Taenia solium cysticerci in carcasses of pigs kept at 4 C

In the present study, the survival of cysticerci of Taenia solium in carcasses of 1 Small-Ear-Miniature and 2 Landrace Small-Ear-Miniature pigs kept in a refrigerator at 4 C was determined. The viability of the cysticerci was determined by observing evagination and active movement of the scolex under a fluorescent light after digestion in pig bile. Although no viable cysticerci were found after day 30, 58.8% cysticerci survived between day 26 and day 30. Moreover, more than 80% of the cysticerci were viable between day 1 and day 25. These findings indicate that taeniasis solium can be transmitted through eating raw or undercooked pork or viscera of pigs following refrigeration at 4 C for less than 30 days.     

Ferroic Phase Transitions in (Na1/2Bi1/2)TiO3 Crystals

The ferroic phase-transition behavior of two (Na_1/2Bi_1/2)TiO₃(NBT) crystals grown by flux and by the Czochralski method has been investigated in the present study. Although both the tetragonal and the rhombohedral phases of NBT are expected to be ferroelastic, these crystals exhibit different ferroelastic behavior. The two NBT crystals also show differences in the amount of temperature hysteresis and the thermal expansion coefficients. These differences can be attributed to nonstoichiometry and structural variations dependent on the growing method. The present investigation has revealed a second maximum at −450°C in dielectric constant (( T )) curves, which could indicate that the intermediate tetragonal phase is either polar or antipolar. This maximum, however, originates from space-charge polarization and interaction between the charge carrier and the electrode, such that the tetragonal phase, in fact, is para-electric. The diffuse phase transition (DPT) of the NBT crystal, therefore, is from a paraelectric and ferroelastic tetragonal phase to a ferroelectric and ferroelastic rhombohedral phase. The crystallographic supergroup-subgroup relationships in the ferroic phase transitions of NBT crystals are discussed.