57 research outputs found

    Stent-Jack Technique for Ruptured Vertebral Artery Dissecting Aneurysm Involving the Origin of Posterior Inferior Cerebellar Artery

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    We herein report a case of a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery that was treated using the stent-jack technique. After parent artery occlusion of the distal vertebral artery, stenting of the posterior inferior cerebellar artery was performed. Further coiling was needed because distal vertebral artery recanalization occurred due to transformation of the coil mass. The stent-jack technique for a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery is effective; however, careful attention to recanalization after stenting is needed due to transformation of the coil mass

    Chemical Characterization of a Volatile Dubnium Compound, DbOCl3

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    The formation and the chemical characterization of single atoms of dubnium (Db, element 105), in the form of its volatile oxychloride, was investigated using the on-line gas phase chromatography technique, in the temperature range 350–600 °C. Under the exactly same chemical conditions, comparative studies with the lighter homologues of Group 5 in the Periodic Table clearly indicate the volatility sequence being NbOCl3 > TaOCl3 ≄ DbOCl3. From the obtained experimental results, thermochemical data for DbOCl3 were derived. The present study delivers reliable experimental information for theoretical calculations on chemical properties of transactinides

    Study of fission using multi-nucleon transfer reactions

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    Multi-nucleon transfer channels of the reactions of 18O+232Th, 18O+238U, 18O+248Cm were used to measure fission-fragment mass distribution for various nuclides and their excitation energy dependence. Predominantly asymmetric fission is observed at low excitation energies for all the studied cases, with an increase of the symmetric fission towards high excitation energies. Experimental data are compared with predictions of the fluctuation-dissipation model, where effects of multi-chance fission (neutron evaporation prior to fission) was introduced. It was shown that a reliable understanding of the observed fission fragment mass distributions can be obtained only invoking multi-chance fissions

    Role of Enhanced Visibility in Evaluating Polyposis Syndromes Using a Newly Developed Contrast Image Capsule Endoscope

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    Online chemical adsorption studies of Hg, Tl, and Pb on SiO2 and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA

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    Online gas-solid adsorption studies with single-atom quantities of Hg, Tl, and Pb, the lighter homologs of the superheavy elements (SHE) copernicium (Cn, Z =112), nihonium (Nh, Z =113), and flerovium (Fl, Z =114), were carried out using short-lived radioisotopes. The interaction with Au and SiO 2 surfaces was studied and the overall chemical yield was determined. Suitable radioisotopes were produced in fusion-evaporation reactions, isolated in the gas-filled recoil separator TASCA, and flushed rapidly to an adjacent setup of two gas chromatography detector arrays covered with SiO 2 (first array) and Au (second array). While Tl and Pb adsorbed on the SiO 2 surface, Hg interacts only weakly and reached the Au-covered array. Our results contribute to elucidating the influence of relativistic effects on chemical properties of the heaviest elements by providing experimental data on these lighter homologs

    Experimental fission study using multi-nucleon transfer reactions

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    It is shown that the multi-nucleon transfer reactions is a powerful tool to study fission of exotic neutron-rich actinide nuclei, which cannot be accessed by particle-capture or heavy-ion fusion reactions. In this work, multi-nucleon transfer channels of the reactions of Âč⁞O+ÂČÂłÂČTh, Âč⁞O+ÂČ³⁞U and Âč⁞O+ÂČ⁎⁞Cm are used to study fission for various nuclei from many excited states. Identification of fissioning nuclei and of their excitation energy is performed on an event-by-event basis, through the measurement of outgoing ejectile particle in coincidence with fission fragments. Fission fragment mass distributions are measured for each transfer channel. Predominantly asymmetric fission is observed at low excitation energies for all studied cases, with a gradual increase of the symmetric mode towards higher excitation energy. The experimental distributions are found to be in general agreement with predictions of the fluctuation-dissipation model. Role of multi-chance fission in fission fragment mass distributions is discussed, where it is shown that mass-asymmetric structure remaining at high excitation energies originates from low-excited nuclei by evaporation of neutrons

    Large scale production of 64Cu and 67Cu via the 64Zn(n, p)64Cu and 68Zn(n, np/d)67Cu reactions using accelerator neutrons

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    Both 64Cu and 67Cu are promising radionuclides in nuclear medicine. Production yields of these radionuclides were quantified by irradiating 55.4 g of natural zinc with accelerator neutrons. Clinically suitable 64Cu and 67Cu yields were estimated by experimental based numerical simulations using 100 g of enriched 64Zn and 68Zn, respectively, and elevated neutron fluxes from 40 MeV, 2 mA deuterons. A combined thermal- and resin-separation method was developed to isolate 64Cu and 67Cu from zinc, resulting in 73% separation efficiency and 97% zinc recovery. Such methods can provide large scale production of 64Cu and 67Cu for clinical applications

    Evaluating the potential of immunotherapy and chemoimmunotherapy in the treatment of elderly non-small cell lung cancer patients: A real-world study

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    Background: Immune checkpoint inhibitor (ICI) has become the standard therapy for metastatic non-small cell lung cancer (NSCLC) patients. However, no robust evidence on the efficacy and safety of ICI in elderly NSCLC patients has been established. Materials and Methods: This retrospective study aimed to assess the efficacy and safety of ICI in elderly NSCLC patients. NSCLC patients treated with ICI monotherapy or chemoimmunotherapy (CIT) between 2016 and 2022 were divided into two cohorts according to the age: the Elderly cohort (patients aged ≄ 75 years) and the Nonelderly cohort (patients aged < 75 years). The progression-free survival (PFS), tumor response, and frequency of immune-related adverse events (irAEs) were compared between the two cohorts. Results: A total of 111 NSCLC patients were included in this study (41 patients in the Elderly cohort and 70 patients in the Nonelderly cohort). The PFS (5.6 months vs. 6.3 months, P = 0.98), response rate (36.6% vs. 44.9%, P = 0.51), and disease control rate (80.5% vs. 76.8%, P = 0.83) were not significantly different between the two cohorts. In a subgroup analysis, stratified according to PD-L1 expression (low vs. high) and ICI treatment mode (ICI monotherapy vs. CIT), the PFSs of both cohorts were also not significantly different, regardless of PD-L1 expression. Moreover, the frequency of irAEs did not significantly differ between elderly and nonelderly NSCLC patients (21/41 [51.2%] vs. 38/70 [54.3%], P = 0.91). Conclusion: The efficacy and safety of ICI in elderly NSCLC patients were not inferior to those in younger patients
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