A field survey was conducted to investigate the metal contamination in soils and vegetables, and to evaluate the possible health risks to local population through foodchain transfer near a smelter in ...Nanning, southern China. Contamination levels in soils and vegetables with cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu) were measured, and transfer factors (TF) from soils to vegetable plants and its health risk (risk index, RI) were calculated accordingly. Results showed that both soils and vegetables from villages 1 and 2 (V1 and V2, 1500 m and 500 m from the smelter) were heavily contaminated, compared to a village 50 km from the smelter. Geometric mean of Cd and Pb concentrations in vegetables for V1 and V2, respectively, were 0.15 and 0.24 mg Cd kg
−1 and 0.45 and 0.38 mg Pb kg
−1 (on fresh weight basis). Oral intake of Cd and Pb through vegetables poses high health risk to local residents. Risk indices for V1 and V2, respectively, were 3.87 and 7.42 for Cd, and 1.44 and 13.5 for Pb. The complexity of metal contamination and their health risks are also discussed.
CsI calorimeter for the J-PARC KOTO experiment Sato, K.; Lee, J.W.; Banno, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2020, Letnik:
982, Številka:
C
Journal Article
Recenzirano
Odprti dostop
An electromagnetic calorimeter made of undoped CsI crystals is used in the J-PARC KOTO experiment to search for new physics beyond the standard model with the KL→π0νν̄ decay. The calorimeter is ...designed to operate in vacuum of 0.1 Pa and in a high-rate environment where the counting rate due to KL decays is O(100) kHz. A special method to calibrate the calorimeter during the data taking without using a tracking system for charged particles is reported. The energy, position, and timing resolutions of the calorimeter were evaluated in several beam tests, and the resolutions satisfy the required performance. The energy resolution with the total energy E is 0.66⊕1.81∕EGeV% in the inner region of the calorimeter.
We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft–Walton (CW) photomultiplier tube base with ...a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1MeV range. We achieved a final noise level below 180μVrms for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases power distribution was also designed. This system is able to control and monitor the high voltage of each individual base.
In the present study, we examined the luminescent properties of uncured and cured samarium tris-(2-thenoyltrifluoroacetone)-1,10-phenanthroline/nitrile rubber composites (Sm(TTA)
3phen/NBR, i.e. ...Sm-complex/NBR). The formula of Sm-complex was determined by infrared spectroscopy (IR) and elementary analysis. The composites were investigated and characterized by photoluminescent (PL) spectroscopy, scanning electron microscopy (SEM) and X-rays diffraction (XRD). The characteristic emission fluorescent intensities of the Sm
3+ in both uncured and cured composites increase with the increase of Sm-complex content. For the nitrile rubber composites with the same content of Sm(TTA)
3phen, the uncured composites are found to have lower luminescent intensity than that of cured composites. To explain this result, we propose that the cross-linking network structure can help to stabilize the coordination environment of the Sm
3+ ion and improve the energy transfer efficiency from the outside energy to the central Sm
3+ ion. In our study, the rare earth organic complexes were dispersed homogeneously into the NBR matrix. The fluorescent intensity of the composites was high and no fluorescent quenching had been observed until the complexes concentration was up to 14.3%.
Though it is well known that humans perceive the temporal features of the environment incessantly, the brain mechanisms underlying temporal processing are relatively unexplored. Functional magnetic ...resonance imaging was used in this study to identify brain activations during sustained perceptual analysis of auditorally and visually presented temporal patterns (rhythms). Our findings show that the neural network supporting time perception involves the same brain areas that are responsible for the temporal planning and coordination of movements. These results indicate that time perception and motor timing rely on similar cerebral structures.
This study sought to explore the predictors of recurrence in patients with paroxysmal atrial fibrillation (AF) undergoing repeat catheter ablation, especially the impact of left atrial (LA) ...remodelling after the original procedure on the outcome of repeat procedure.
Ninety-five patients undergoing repeat ablation were enrolled in this study. Repeat procedure endpoints were pulmonary vein isolation, linear block when linear ablation is performed, and non-inducibility of atrial tachyarrhythmia by burst pacing. Patients with LA enlargement between the pre-original procedure and pre-repeat procedure were categorized as Group 1 (35 patients), while individuals with no change or decrease of LA diameter were categorized as Group 2 (60 patients). The mean duration from the original procedure to the repeat procedure was 12 months (1-40 months). After 29.6 ± 20.5 (3-73) months follow-up from the repeat procedure, 33 patients experienced recurrence (34.7%). The recurrence rate was significantly higher in Group 1 than in Group 2 (51.4 VS. 25.0%, P = 0.017). In univariate analysis, LA remodelling was the only predictor of recurrence. In multivariate analysis, after adjustment for age and LA diameter, Group 1 had a greater risk of recurrence after the repeat procedure (hazard ratio = 2.22, 95% confidence interval: 1.02-4.81, P = 0.043).
Left atrial enlargement after undergoing the original catheter ablation of paroxysmal AF was an independent risk factor of recurrence after repeat ablation.
A pulse shape difference between photons and neutrons was observed in the output signals of scintillation light from the un-doped CsI calorimeter of the KOTO experiment for the KL→π0νν̄ decay. We ...developed a discrimination method to reject neutrons and to accept photons in the deposited energy range from 0.1 to 2 GeV. The method rejects 67% of neutron-induced single hadronic clusters and 86% of neutron-induced two-cluster events while keeping more than 90% of photon-induced single electromagnetic clusters and two-photon events.
Lesion and imaging studies have suggested that the premotor cortex (PMC) is a crucial component in the neural network underlying the processing of sequential information. However, whether different ...aspects of sequential information like interval and ordinal properties are supported by different anatomical regions, and whether the representation of sequential information within the PMC is necessarily related to motor requirements, remain open questions. Brain activations were investigated during a sequence encoding paradigm in 12 healthy subjects using functional magnetic resonance imaging. Subjects had to attend either to the interval or to the ordinal information of a sequence of visually presented stimuli and had to encode the relevant information either before motor reproduction or before perceptual monitoring. Although interval and ordinal information led to activations within the same neural network, direct comparisons revealed significant differences. The pre-supplementary motor area (preSMA), the lateral PMC, the frontal opercular cortex as well as basal ganglia and the left lateral cerebellar cortex (CE) were activated significantly more strongly by interval information, whereas the SMA, the frontal eye field, the primary motor cortex (MI), the primary somatosensory cortex, the cuneus as well as the medial CE and the thalamus were activated more strongly by ordinal information. In addition, serial encoding before reproduction led to higher activations than serial encoding before monitoring in the preSMA, SMA, MI and medial CE. Our findings suggest overlapping but different kinds of sequential representation, depending on both the ordinal and interval aspects as well as motor requirements.
Aims
The aim of this study was to identify the impact of obstructive sleep apnoea (OSA) on recurrence after catheter ablation of paroxysmal atrial fibrillation (AF).
Methods and results
One hundred ...and seventy-eight consecutive patients with paroxysmal AF who underwent index circumferential pulmonary vein (PV) isolation were prospectively enrolled. The patients were divided into high risk (HR group) and low risk (LR group) for OSA group with Berlin questionnaire. Of the 178 patients, 104 (58.4%) were in the HR group and 74 (41.6%) were in the LR group. After a mean follow-up of 344 ± 137 (91-572) days, 44 patients (24.7%) experienced recurrence, and the recurrence rate did not differ between the HR (25.0%) and LR groups (24.3%, P = 0.855). Cox analysis revealed that PV isolation was the only independent predictor of recurrence (hazard ratio 5.11, 95% confidence interval 1.42-18.47, P = 0.013). There was no significant difference in the incidence of complications between the HR and LR groups (2.9 vs. 1.9%, P = 0.729).
Conclusion
The recurrence rate and incidence of complications did not differ in patients with different risk profiles for OSA. The presence of OSA should not lower the decision threshold to choose an ablative procedure in paroxysmal AF.
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