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This paper focuses on the evaluation of scanning devices for in-pile radiation measurement of the shut-down uranium–graphite reactors. The description of several generations of scanning devices is presented cause their design and configuration has been constantly improved in the light of experience and new objectives. Approaches and results of determining the metrological characteristics of γ- and neutron detectors of various types directly in reactor designs in which mixed radiation (α-, β-, γ-, and neutron radiation) prevails are considered. Estimates of the influence of the energy dependence of the sensitivity on the γ-detectors readings of different types, as well as the neutron detectors noise-immunity to γ-radiation, are presented. [ABSTRACT FROM AUTHOR]

The paper focuses on the 14C, 36C1, and 60Co radionuclide distribution in graphite stacks and blocks, which play a crucial role in the decommission of uranium-graphite reactors. The shutdown uranium-graphite reactor ADE-5 provides an access to the graphite stack for the removal of graphite blocks. New interpretations are suggested for the radionuclide distribution in bulk graphite stacks based on testing results of graphite blocks removed from the uranium-graphite reactor ADE-5 in 2018. [ABSTRACT FROM AUTHOR]

The release of long-lived radionuclides 14C and 36Cl , which are key products for assessment of disposal variants (near-surface, buried, or deep) of irradiated graphite, was analyzed. Test material was irradiated graphite from IUGR and RBMK-1000 reactors. Unlike other types of radioactive waste (RAW), graphite has the developed pore structure and, consequently, its effective surface area in contact with the leaching medium is increased in comparison with non-porous materials. With due to regard for the graphite pore structure, the mechanism describing the leaching process is proposed and experimentally substantiated. The parameters numerically characterizing graphite RAW in terms of leaching resistance, independent of the geometric shape of individual fragments (samples) are also introduced. The proposed parameters and an algorithm for their determination are recommended by the authors for use in predictive calculations of the release of radionuclides from graphite under conditions of long-term storage/disposal. [ABSTRACT FROM AUTHOR]

Specific features of the porous structure of irradiated and virgin reactor graphite of Russian brands have been analyzed. The porosity parameters affecting the leaching of radionuclides from graphite radioactive waste (RAW) were determined: fraction of open porosity, distribution of pore throat cross-sections, surface of open pores. The volume of open pores accessible for leaching aqueous media in the irradiated graphite was estimated. A model describing the leaching of radionuclides from irradiated graphite accounting for the porosity contribution is proposed. The parameters that numerically characterize the resistance of graphite RAW against leaching and are independent of the geometric shapes of separate fragments (samples) were determined. [ABSTRACT FROM AUTHOR]

Purpose: Multi-detector computed tomography (MDCT) has proven to be of value for the reconstruction of trajectories of projectiles and the assessment of the injuries in deceased gunshot victim. For the depiction of soft tissue injury, MRI is superior to MDCT and MRI may be of value to assess trajectories. In a clinical setting, there are guidelines for the application of MRI in patients with projectiles or projectile fragments and with precautions MRI is safe for these patients. However, this has not been studied for the postmortem application of MRI from a forensic point of view. Subjects and method: To assess the behaviour of projectiles, two ferromagnetic and one non-ferromagnetic projectile were exposed to the magnetic field of a 1.5- and 3-T MRI. Projectiles were placed in six phantoms with the characteristics of human muscle tissue, with and without a simulated trajectory in the gel. Before and after exposure to the magnetic field, the gelatine phantoms were imaged with MDCT to assess the position of the projectiles. Results: The ferromagnetic projectiles rotate to a position where their long axis is parallel to the z-axis of the magnetic field and five out of the six projectiles moved through, either through the simulated trajectory or through a new trajectory. This was observed in both the 1.5- and 3-T systems. Conclusion: Ferromagnetic projectiles can rotate and migrate in a gelatine phantom. It is very likely that these projectiles will also migrate in a human body in a MRI system. Therefore, from a forensic point of view, postmortem MR will make a reconstruction of the trajectories in the body and of the reconstruction of the incident as a whole less reliable. [ABSTRACT FROM AUTHOR]

Zinc-finger, MYND-type containing 10 (ZMYND10), or more commonly called BLU, expression is frequently downregulated in nasopharyngeal carcinoma (NPC) and many other tumors due to promoter hypermethylation. Functional evidence shows that the BLU gene inhibits tumor growth in animal assays, but the detailed molecular mechanism responsible for this is still not well understood. In current studies, we find that 93.5% of early-stage primary NPC tumors show downregulated BLU expression. Using a PCR array, overexpression of the BLU gene was correlated to the angiogenesis network in NPC cells. Moreover, expression changes of the MMP family, VEGF and TSP1, were often detected in different stages of NPC, suggesting the possibility that BLU may be directly involved in the microenvironment and anti-angiogenic activity in NPC development. Compared with vector-alone control cells, BLU stable transfectants, derived from poorly-differentiated NPC HONE1 cells, suppress VEGF165, VEGF189 and TSP1 expression at both the RNA and protein levels, and significantly reduce the secreted VEGF protein in these cells, reflecting an unknown regulatory mechanism mediated by the BLU gene in NPC. Cells expressing BLU inhibited cellular invasion, migration and tube formation. These in vitro results were further confirmed by in vivo tumor suppression and a matrigel plug angiogenesis assay in nude mice. Tube-forming ability was clearly inhibited, when the BLU gene is expressed in these cells. Up to 70-90% of injected tumor cells expressing increased exogenous BLU underwent cell death in animal assays. Overexpressed BLU only inhibited VEGF165 expression in differentiated squamous NPC HK1 cells, but also showed an anti-angiogenic effect in the animal assay, revealing a complicated mechanism regulating angiogenesis and the microenvironment in different NPC cell lines. Results of these studies indicate that alteration of BLU gene expression influences anti-angiogenesis pathways and is important for the development of NPC. [ABSTRACT FROM AUTHOR]

Many of the cancer cell lines derived from solid tumors are difficult to transfect using commonly established transfection approaches. This hurdle for some DNA transfection systems has hindered cancer biology studies. Moreover, there are limited tools for studying pathway activities. Therefore, highly efficient improved gene transfer and versatile genetic tools are required. In this study, we established and developed a comprehensive set of new lentiviral tools to study gene functions and pathway activities. Using the optimized conditions, cancer cell lines achieved >90% transduction efficiency. Novel lentiviral doxycycline-regulated pTet-IRES-EGFP (pTIE) systems for transgene expression and TRE reporters used for pathway activity determination were developed and tested. The pTIE Tet-Off system showed in vitro doxycycline-sensitive responses with low or undetectable leakage of protein expression and in vivo tumor suppression as illustrated using candidate tumor suppressors, Fibulin-2 and THY1. In contrast, the Tet-On system showed dose-dependent responses. The pTRE-EGFP (pTE) and pTRE-FLuc-EF1α-RLuc (pT-FER) reporters with the NFκB p65 subunit consensus sequence showed GFP and firefly luciferase responses, which were directly correlated with TNFα stimulation, respectively. Taken together, these newly developed lentiviral systems provide versatile in vitro and in vivo platforms to strengthen our capabilities for cancer biology studies. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is a cancer that occurs in high frequency in Southern China. A previous functional complementation approach and the subsequent cDNA microarray analysis have identified that serum amyloid A1 (SAA1) is an NPC candidate tumor suppressor gene. SAA1 belongs to a family of acute-phase proteins that are encoded by five polymorphic coding alleles. The SAA1 genotyping results showed that only three SAA1 isoforms (SAA1.1, 1.3 and 1.5) were observed in both Hong Kong NPC patients and healthy individuals. This study aims to determine the functional role of SAA1 polymorphisms in tumor progression and to investigate the relationship between SAA1 polymorphisms and NPC risk. Indeed, we have shown that restoration of SAA1.1 and 1.3 in the SAA1-deficient NPC cell lines could suppress tumor formation and angiogenesis in vitro and in vivo. The secreted SAA1.1 and SAA1.3 proteins can block cell adhesion and induce apoptosis in the vascular endothelial cells. In contrast, the SAA1.5 cannot induce apoptosis or inhibit angiogenesis because of its weaker binding affinity to αVβ3 integrin. This can explain why SAA1.5 has no tumor-suppressive effects. Furthermore, the NPC tumors with this particular SAA1.5/1.5 genotype showed higher levels of SAA1 gene expression, and SAA1.1 and 1.3 alleles were preferentially inactivated in tumor tissues that were examined. These findings further strengthen the conclusion for the defective function of SAA1.5 in suppression of tumor formation and angiogenesis. Interestingly, the frequency of the SAA1.5/1.5 genotype in NPC patients was ~2-fold higher than in the healthy individuals (P=0.00128, odds ratio=2.28), which indicates that this SAA1 genotype is significantly associated with a higher NPC risk. Collectively, this homozygous SAA1.5/1.5 genotype appears to be a recessive susceptibility gene, which has lost the antiangiogenic function, whereas SAA1.1 and SAA1.3 are the dominant alleles of the tumor suppressor phenotype. [ABSTRACT FROM AUTHOR]

Homosexuality is now accepted as a normal variant of human sexuality, but homophobia among healthcare professionals is well documented. Establishment of trustful doctor-patient relationships is impossible in the presence of homophobia. We were interested to examine the extent of homophobia among medical students, the future doctors. This article aims to study attitudes of medical students of the University of Hong Kong towards homosexuality and to identify significant factors affecting their attitudes. A cross-sectional study was performed on students of the University of Hong Kong. Attitudes towards homosexuality were compared between medical and non-medical students. More than 25% of the medical students agreed with the statement 'homosexuality is a psychological disorder that requires therapy'. More than 15% would avoid any physical contact with homosexuals to minimise the chance of contracting diseases, especially AIDS. Comparison between the medical students and non-medical students showed that the attitudes of the medical students were significantly more homophobic. Factors explaining the difference included the importance of religion in the formation of moral values, gender, experience of working closely with homosexual friends, sexual orientation, experience of the heterosexual sexual act, acquaintance of homosexual friends, and experience of homosexual love relationships. In conclusion, there appeared to be a certain level of homophobia among the medical students. This could possibly be explained by their lack of experience of working closely with homosexual friends. Relevant curriculum modification and development are urgently needed, to provide ongoing opportunities for students to realise their own values that could unconsciously affect their clinical judgements. [ABSTRACT FROM AUTHOR]

In order to investigate the compressive mechanical characteristics of Sm 123 single-grain bulk superconductors fabricated by TSMG method, compressive tests in the direction parallel and perpendicular to the c-axis have been carried out by using small specimens cut from the bulk samples. Stress-strain curves in the direction perpendicular to the c-axis were almost linear. The Young's moduli measured were 155-165 GPa. In the case of loading parallel to the c-axis, the curves were exponential in the low stress region. As the stress increased, they tended to a linear relation. The apparent Young's modulus in this region was 75-110 GPa. These characteristics are mainly ascribed to the closure behavior of pre-existing micro-cracks perpendicular to the c-axis. The average fracture strength in the direction of c-axis, 350-400 MPa, was larger than that perpendicular to it, 235-275 MPa. Specimens in the former were generally broken into great many small pieces while those in the latter were broken into some parts by lateral cracking. The compressive Young's modulus and the fracture strength for each direction were higher than those evaluated by the tensile loading, respectively. The effects of specimen length on the compressive mechanical properties were also discussed. [ABSTRACT FROM AUTHOR]

Presents a case of dehydration and renal insufficiency during rapid opioid detoxification without general anesthesia. Laboratory profile of the patient; Administration of opioid antagonist naltrexone; Presence of withdrawal symptoms.