We developed an omnidirectional Compton camera for radioactive environmental monitoring which can visualize gamma rays with energy below 250 keV emitted from various radiopharmaceuticals used in ...nuclear medicine facilities to prevent occupational radiation exposure. An omnidirectional Compton camera based on high light yield scintillators CsI(Tl) or NaI(Tl) developed in our previous studies is a promising system for environmental radiation monitoring because it has a wide field of view and high sensitivity for sub-MeV gamma rays. However, its sensitivity rapidly decreases below 250 keV because photoelectric effect becomes more dominant than the Compton scattering process due to their large effective atomic numbers (approximately 50). Thus, CaF2(Eu) was adopted, which has both low effective atomic number (approximately 15) and high light yield. Four CaF2(Eu) crystals were arranged symmetrically to achieve a relatively uniform acceptance in all directions. Similarly, the detector rotation technique was adopted to suppress artificial patterns in a reconstructed gamma-ray image because of the small number of crystals. Through experiments in a laboratory and at a nuclear medicine facility, the capability of the camera to visualize gamma rays in energies from 250 keV to 60 keV with reasonable observation time for practical clinical use was confirmed.
Multiaxial high cycle fatigue life prediction under constant stress amplitude is proposed. This new criterion, which extends the proposed fatigue limit criterion by the authors in the previous ...papers, uses the unified equivalent shear stress amplitude. The material properties for the proposed criterion are the axial fatigue limit and the true fracture strength. The multiaxial high cycle fatigue tests for life prediction accuracy verification was carried out with S45C and SCM440. The fatigue tests were conducted under combined axial and torsion stresses with mean stress and phase difference. The criterion error is better than that of the Susmel criterion. The proposed criterion predicted the experimental fatigue life to be within a factor of 3.
Olefins can be converted into aziridines by using a chloramine‐T/I2 system, and silica and water as the reaction medium (see picture). Moreover, the ring‐opening reaction of the resulting aziridine ...with an azide or a cyanide ion proceeds in the same medium.
Iodine was found to be an efficient catalyst for the aziridination of alkenes utilizing Chloramine-T (
N-chloro-
N-sodio-
p-toluenesulfonamide) as a nitrogen source. For example, when two equivalents ...of styrene were added to Chloramine-T in the presence of a catalytic amount of iodine in a 1 : 1 solvent mixture of acetonitrile and neutral buffer, the corresponding aziridine
1 was obtained in 91% yield. The reaction could be applied to other acyclic and cyclic alkenes such as 1-octene and cyclohexene. The aziridination of
p-substituted styrene derivatives
2–5 with Chloramine-T showed that electron-rich alkenes reacted faster than electron-poor ones. Several Chloramine-T analogs were also examined and were found to give the corresponding aziridines
8–10 in only moderate yields.
In the presence of catalytic amount of iodine, Chloramine-T serves as a nitrogen source for the aziridination of alkenes.
To investigate 1-year outcomes of intravitreal aflibercept for polypoidal choroidal vasculopathy (PCV).
Retrospective, multicenter, consecutive case series.
A total of 90 eyes of 87 patients with ...treatment-naïve PCV followed at 3 tertiary centers.
Clinical records were reviewed and imaging studies were analyzed of eyes with PCV that underwent 3 consecutive monthly aflibercept injections followed by injections every 2 months. Additional (rescue) injections were performed for worsening.
Best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and angiographic findings at 1 year.
The mean BCVA (logarithm of the minimum angle of resolution units) of the 90 eyes improved from 0.31 at baseline to 0.17 at 12 months (P < 0.001). The mean central retinal thickness decreased from 315 μm at baseline to 204 μm at 12 months (P < 0.001). At 12 months, 64 eyes (71.1%) achieved a dry macula, defined as absence of intraretinal or subretinal fluid on OCT. Of 83 eyes that underwent indocyanine green angiography at both baseline and 12 months, 46 (55.4%) showed complete and 27 (32.5%) showed partial resolution of polypoidal lesions. Eleven of 82 eyes (13.4%) showed decreased size of branching choroidal vascular networks.
Intravitreal aflibercept administered over 1 year improved both visual acuity and macular morphology in a large number of treatment-naïve eyes with PCV.
Abstract Hypoalbuminemia, a frailty criterion, belongs to a group of comorbidities not captured as a traditional risk factor. We assessed its prognostic value in patients who underwent transcatheter ...aortic valve implantation (TAVI). The study included 1215 consecutive patients from the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI Japanese multicenter registry. Hypoalbuminemia was defined as serum albumin level<3.5 g/dL. Baseline characteristics, procedural outcomes, and all-cause, cardiovascular, and non-cardiovascular mortality rates after TAVI were compared between patients with albumin level<3.5 g/dL (hypoh-ALB group, n=284) and those with albumin level>3.5 g/dL (nonhyponh-ALB group, n=931). Several baseline characteristics differed significantly between both groups, including age (85.1±5.1 years vs. 84.2±4.9 years, p=0.012), ejection fraction (58.5±14.3% vs. 62.9±12.4%, p<0.001), baseline kidney function, or liver disease. The 30-day mortality rate in all patients showed significant differences between the 2 groups (3.9% vs. 1.3%, p=0.005). During a mean follow-up of 330 days, cumulative all-cause, cardiovascular, and non-cardiovascular mortality rates were significantly higher in the hALB group than in the nhALB group (log-rank test, p<0.001, p=0.0021, and p<0.001, respectively). The groups were also analysed using a propensity-matching model for adjusting the baseline differences. The analysis revealed that the poorer prognosis of the hALB group in terms of cumulative all-cause and non-cardiovascular mortality was retained (p=0.038, and p=0.0068, respectively); however, differences in cardiovascular mortality rates in the two groups were attenuated (p=0.93). In conclusion, hypoalbuminemia was associated with poor prognosis, highlighted by the increase in non-cardiovascular mortality. Baseline albumin level could be a useful marker for risk stratification before TAVI.
Background Sialic acid–binding immunoglobulin-like lectin (Siglec)-8 is expressed on human eosinophils, where its ligation induces cell death. Paradoxically, Siglec-8–mediated cell death is markedly ...enhanced by the presence of the activation and survival factor IL-5 and becomes independent of caspase activity. Objective In this report we investigate the mechanism of Siglec-8–mediated cell death in activated eosinophils. Methods Human peripheral blood eosinophils were treated with agonistic anti–Siglec-8 antibody and IL-5, and cell death was determined by using flow cytometry and morphology. Phosphorylation of mitogen-activated protein kinase (MAPK) was determined by using phosphoLuminex, flow cytometry, and Western blotting. Reactive oxygen species (ROS) accumulation was determined by using dihydrorhodamine fluorescence. Results Costimulation with anti–Siglec-8 and IL-5 significantly increased the rate and proportion of cell death by means of necrosis accompanied by granule release compared with that seen after stimulation with anti–Siglec-8 alone, in which apoptosis predominated. Together with the caspase-independent mode of cell death in costimulated cells, these findings suggest the activation of a specific and distinct biochemical pathway of cell death during anti–Siglec-8/IL-5 costimulation. Phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and MAPK-ERK kinase (MEK) 1 was significantly enhanced and sustained in costimulated cells compared with that seen in cells stimulated with IL-5 alone; anti–Siglec-8 alone did not cause ERK1/2 phosphorylation. MEK1 inhibitors blocked anti–Siglec-8/IL-5–induced cell death. ROS accumulation was induced by Siglec-8 ligation in a MEK-independent manner. In contrast, an ROS inhibitor prevented the anti–Siglec-8/IL-5–induced enhancement of ERK phosphorylation and cell death. Exogenous ROS mimicked stimulation by anti–Siglec-8 and was sufficient to induce enhanced cell death in IL-5–treated cells. Collectively, these data suggest that the enhancement of ERK phosphorylation is downstream of ROS generation. Conclusions In activated eosinophils ligation of Siglec-8 leads to ROS-dependent enhancement of IL-5–induced ERK phosphorylation, which results in a novel mode of biochemically regulated eosinophil cell death.
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