The response of the EJ 299-33 plastic scintillator to energetic charged nuclear particles ranging from isotopes of hydrogen to isotopes of carbon has been determined over a wide energy range using a ...complex experimental setup and nuclear reactions induced by a 20AMeV carbon beam on an aluminum target. A strong pulse-shape dependence of the generated light bursts on the impinging particle specie is observed, which makes this scintillator suitable, among other things, for neutron vs.γ-ray identification. Fit formulas are proposed for the normalized light output as a function of particle energy for eleven isotopes of elements ranging from hydrogen to carbon.
A study of the response of three ΔE-E telescopes to fragments produced in nuclear interactions at 40AMeV is presented. All the employed telescopes feature silicon carbide (SiC) detectors for at least ...one detection stage. Two identification methods have been used and their performance discussed: the ΔE-E technique and the Pulse Shape Analysis technique (for identification of nuclear fragments stopped in a single SiC layer). Identification capabilities similar to those obtained with the best available silicon detectors have been found for the SiC detector prototypes studied in this work.
The motivation of the present paper is to study the performance of EJ 299-33 scintillator in online and off-line analysis in high rate scattering for nuclear reaction experiments performed with heavy ...ions. An experiment was carried out inside the CHIMERA chamber using 24Mg beams at 71.5 MeV and 81 MeV impinging on 92ZrO2 target. The plastic scintillator was backed by a photomultiplier tube and the anode pulses were digitized through 100 MHz GET electronics for the purpose of pulse shape discrimination (PSD) studies. Performances of the plastic scintillator have been tested with respect to PSD capabilities and energy spectra analysis under beam irradiations in a high background environment.
Almost all biological therapeutic interventions cannot overcome neoplastic heterogeneity. Physical ablation therapy is immune to tumor heterogeneity, but nearby tissue damage is the limiting factor ...in delivering lethal doses. Multi-walled carbon nanotubes offer a number of unique properties: chemical stability, photonic properties including efficient light absorption, thermal conductivity, and extensive surface area availability for covalent chemical ligation. When combined together with a targeting moiety such as an antibody or small molecule, one can deliver highly localized temperature increases and cause extensive cellular damage. We have functionalized multi-walled carbon nanotubes by conjugating an antibody against prostate-specific membrane antigen. In our in vitro studies using prostate-specific membrane antigen–positive LNCaP prostate cancer cells, we have effectively demonstrated cell ablation of >80% with a single 30-s exposure to a 2.7-W, 532-nm laser for the first time without bulk heating. We also confirmed the specificity and selectivity of prostate-specific membrane antigen targeting by assessing prostate-specific membrane antigen–null PC3 cell lines under the same conditions (<10% cell ablation). This suggests that we can achieve an extreme nearfield cell ablation effect, thus restricting potential tissue damage when transferred to in vivo clinical applications. Developing this new platform will introduce novel approaches toward current therapeutic modalities and will usher in a new age of effective cancer treatment squarely addressing tumoral heterogeneity.
The X-linked androgen receptor (AR) gene contains two polymorphic trinucleotide repeat segments that code for polyglutamine and polyglycine tracts in the N-terminal trans-activation domain of the AR ...protein. Changes in the lengths of these polymorphic repeat segments have been associated with increased risk of prostate cancer, an androgen-dependent tumor. Expansion of the polyglutamine tract causes a rare neuromuscular disease, spinal bulbar muscular atrophy, that is associated with low virilization, reduced sperm production, testicular atrophy, and infertility. As spermatogenesis is exquisitely androgen dependent, it is plausible that changes in these two repeat segments could have a role in some cases of male infertility associated with impaired spermatogenesis. To test this hypothesis, we examined the lengths of the polyglutamine and polyglycine repeats in 153 patients with defective sperm production and compared them to 72 normal controls of proven fertility. There was no significant association between the polyglycine tract and infertility. However, patients with 28 or more glutamines (Gln) in their AR had more than 4-fold (95% confidence interval, 4.9-3.2) increased risk of impaired spermatogenesis, and the more severe the spermatogenic defect, the higher the proportion of patients with a longer Gln repeat. Concordantly, the risk of defective spermatogenesis was halved when the polyglutamine tract was short (< or = 23 Gln). Whole cell transfection experiments using AR constructs harboring 15, 20, and 31 Gln repeats and a luciferase reporter gene with an androgen response element promoter confirmed an inverse relationship between Gln number and trans-regulatory activity. Immunoblot analyses indicated that the reduced androgenicity of the AR was unlikely to be due to a change in AR protein content. The data indicate a direct relation between length of the AR polyglutamine tract and the risk of defective spermatogenesis that is attributable to the decreased functional competence of AR with longer glutamine tracts.
It is discussed the dynamics of Isospin equilibration in reactions involving the production of Intermediate Mass Fragment (IMF) in the mid-rapidity region. The investigation proceeds through the ...measurements of the reduced value of the total dipolar signal obtained from the measured velocities and charges of all fragments produced in the collision 48Ca +27 Al at 40 MeV/nucleon. Preliminary experimental results, along with the comparison with CoMD-III model calculations for different density functionals related to the symmetry energy, are presented.
It has been anticipated that new, much more sensitive, next generation sequencing (NGS) techniques, using massively parallel sequencing, will likely provide radical insights into the genetics of ...multifactorial diseases. While NGS has been used initially to analyze individual human genomes, and has revealed considerable differences between healthy individuals, we have used NGS to examine genetic variation within individuals, by sequencing tissues “in depth”, i.e., oversequencing many thousands of times. Initial studies have revealed intra-tissue genetic heterogeneity, in the form of multiple variants of a single gene that exist as distinct “majority and “minority” variants. This highly specialized form of somatic mosaicism has been found within both cancer and normal tissues. If such genetic variation within individual tissues is widespread, it will need to be considered as a significant factor in the ontogeny of many multifactorial diseases, including cancer. The discovery of majority and minority gene variants and the resulting somatic cell heterogeneity in both normal and diseased tissues suggests that selection, as opposed to mutation, might be the critical event in disease ontogeny. We, therefore, are proposing a hypothesis to explain multifactorial disease ontogeny in which pre-existing multiple somatic gene variants, which may arise at a very early stage of tissue development, are eventually selected due to changes in tissue microenvironments.
We have reported that polyglutamine (polyGln)-expanded human androgen receptors (hAR) have reduced transactivational competence in transfected cells. We presumed that maximal hAR transactivation ...requires a normal-size polyGln tract. Here we report, however, that hAR transactivity and polyGln-tract length are related inversely: n = 0 > 12 > 20 > 40 > 50. Thus, a normal-size polyGln tract represses the transactivational competence of a polyGln-free hAR, and polyGln expansion increases that negative effect. This observation has pathogenetic implications for X-linked spinobular muscular atrophy (Kennedy syndrome), and possibly for the autosomal dominant central neuronopathies associated with (CAG)n expansion in the translated portion of four different genes.
The response of the EJ 299-33 plastic scintillator to energetic charged nuclear particles ranging from isotopes of hydrogen to carbon-12 has been analyzed in terms of Birks׳ semi-empirical approach ...over the wide range of particle energies from 2 to 20AMeV. It was found that while the original two-parameter scaling involving Birks׳ composite quenching parameter kB and an overall conversion efficiency parameter S may be applicable to select sets of particles, a more universal fit would still require individual scintillation efficiencies Sx for individual particle species and more than just one value of the composite Birks׳ constant kB.
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