Search

Thirty-five years ago, Sir Michael Berry and his collaborator Mondragon studied the behaviors of neutrino, a massless relativistic quantum particle, in a classically chaotic billiard—the neutrino billiard problem. To celebrate Sir Michael Berry’s eightieth birthday, here we report results on the role of geometric symmetries of the billiard system in relativistic quantum scarring. In particular, we investigate a Dirac billiard system with a four-fold rotational symmetry whose classical dynamics are fully chaotic. The system is described by the massless Dirac equation in the fundamental domain that consists of one fourth of the full billiard, with proper boundary conditions on the symmetry lines to preserve the physical properties under the symmetry operations. We show that the relativistic quantum characteristics of spin induced phase play a fundamental role in the quantum behaviors of the Dirac particle in the billiard. We find that the peaks in the length spectra are due to the interference of states circling the fundamental domain orbits (FDOs) in opposite propagating directions, which can be constructive or destructive depending on the accumulated phases. In addition, we derive the quantization conditions of the scarring states about the unstable periodic orbits within the fundamental domain from the phase along the FDOs. Our work is a vivid demonstration that relativistic quantum scarring, or more generally quantum manifestations of classical chaos, can be fully understood by analyzing the behaviors of the geometric phase—a powerful approach in modern physics pioneered by Sir Michael Berry.

Background To investigate the value of double-balloon endoscopy(DBE), CT enterography (CTE) and their combination for the diagnosis of small bowel Crohn disease(CD). Methods Data of 35 patients admitted from January 2018 to December 2019 who were clinically suspected of small bowel CD undergoing double-balloon endoscopy(DBE) were reviewed. 30 patients underwent CT enterography (CTE). Diagnosis was made based on pathological, endoscopic findings, CT enterography findings and clinic follow-up results. Detection rates and diagnosis rates of small bowel CD were compared by double-balloon enteroscopy(DBE) and CT enterography(CTE). Results The detection and diagnosis rates of small bowel CD by double-balloon endoscopy (DBE) were 97.1%(34/35) and 91.2%(31/34), respectively. These two variables by CT enterography(CTE) were 86.7%(26/30) and 88.5%(23/26). Both double balloon enteroscopy (DBE) and CT enterography (CTE) detected small intestinal CD in 25 cases, with a detection rate of 83.3% (25/30) and a diagnosis rate of 92%(23/25). The detection rate and diagnosis rate of double balloon enteroscopy (DBE) were higher than that of CT enterography(CTE). Double balloon enteroscopy(DBE) combined with CT enterography(CTE) has the highest rate of diagnosis. Conclusions Double balloon enteroscopy(DBE) has high application value for the diagnosis of small bowel CD, and can be recommended as the first choice for the diagnosis of small bowel CD. For those contraindicated with endoscopy, CT enterography(CTE) can be considered as a preferred auxiliary diagnostic modality. The combination of the two methods can complement each other and provide more information for the diagnosis of small bowel CD, thus improving the diagnosis rate of small intestinal CD.

Background To investigate the best interval time between gastric preparation and magnetic-controlled capsule endoscopy by comparing the effect of various interval time on image quality of stomach, safety, tolerance and positive lesions through a randomized controlled trial. Methods 80 patients referred for MCE from Jan. 2018 to Dec. 2018 were randomly assigned to three groups, interval time with 30 minute and less (A), 30 to 60 minutes (B) or 60 minutes and more (C). All patients fasted for at least 8 hours before MCE and administrated with dimethicone, pronase and sodium bicarbonate. Cleanliness and visualization scores, safety, tolerability, additional water required and diagnostic sensitivity were compared. A multi-factor analysis of cleanliness and visualization scores was conducted. Results The total cleanliness scores were (mean±SD) 20.44±2.61 (A), 20.96±1.68 (B), and 20.56±2.90 (C). The total visualization scores (mean±SD) were 16.33±2.01 (A), 16.41±1.50 (B), and 16.07±1.96 (C). There was no statistical difference among groups A, B and C (P>0.05). MCE detected positive findings in 16 (59.3%), 18(66.7%) and 15 (55.6%) patients in group A, B and C respectively, with no significant difference between groups (P>0.05). Additional water required during MCE were (mean±SD) 107.41±70.31 mL(A),46.30±39.04 mL(B),79.63±65.43 mL(C), and it was much less in group B than the other two groups (P=0.003). There was a negative correlation between cleanliness and visualization scores and the infection of H. pylori (rs=-0.326, P=0.003 and rs=-0.235, P=0.035). Conclusions Patients administrated with dimethicone, pronase and sodium bicarbonate 30 minute and less, 30 to 60 minutes, 60 minutes and more were not statistically different in cleanliness, visualization and positive rates. But groups of 30 to 60 minutes got the least supplement of water during MCE, and it may be the best interval time between gastric preparation and MCE.

Sodium doped Calcium Barium Niobate (Na:CBN) is of potential use in integrated optical devices with high-power laser operation because of its unique nonlinear optical properties and the high Curie temperature. In our work, we research the fabrication and properties of planar Na:CBN waveguide by multiple energy He ion implantation. The sample is implanted with (450 + 500 + 550) keV He ions at room temperature with fluence of (3 + 3 + 3) × 1016 ions/cm2. Prism-coupling and end-face coupling measurements are used to investigate the optical properties of ion-implanted Na:CBN crystal. SRIM and FD-BPM simulations have been used to study the damage formation and light propagation process on the Na:CBN waveguide. Micro-Raman imaging is a powerful nondestructive approach to examine lattice modification and local micro-structural change. We perform confocal micro-Raman measurement, which is used to provide the information about the crystal structure of Na:CBN crystal after multiple energy He ion implantation. This work could provide useful information for integrated optical device based on Na:CBN crystal.

To evaluate aesthetic outcomes in patients with bilateral trapezius hypertrophy treated by botulinum toxin type A (BTxA) injection for aesthetic reconstruction of the upper trapezius. From May 2015 to May 2016, 30 women with a short neck shape resulting from bilateral trapezius hypertrophy were treated with botulinum toxin type A (BTxA) injection at the most affected area of the upper trapezius. Pre- and postoperative values of SACDF (irregularly shaped area of the four points A, C, D, and F) and SACDE (irregularly shaped area of the four points A, C, D, and E), responses to patients’ and doctors’ Global Aesthetic Improvement Scale (GAIS) questionnaires for neck aesthetic assessment, as well as reported adverse events, were recorded and analyzed. Duration of follow-up ranged from 4 to 12 months. Subjects experienced non-severe adverse events and complete recovery after a single BTxA injection. In patients’ GAIS questionnaires, “very much improved” accounted for 53%, “much improved” accounted for 13%, and “improved” accounted for 27%. In doctors’ GAIS questionnaires, “very much improved” accounted for 27%, “much improved” accounted for 33%, “improved” accounted for 33%, and “no change” accounted for 7%. The overall degree of improvement was high. Statistically significant differences were observed with respect to the “very much improved” response to GAIS questionnaires between patients and doctors (P = 0.035). A single injection of BTxA for aesthetic reconstruction of the upper trapezius is safe and effective in patients with bilateral trapezius hypertrophy. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ionic liquid [BIm]Cl/CuCl was synthesized by two-step synthesis using 1-butylimidazole, HCl and CuCl as raw materials. Structure of [BIm]Cl/CuCl was characterized by FT-IR and FT-ICR MS. The interactions between [BIm]Cl/CuCl and thiol were analyzed by DSC, FT-IR and UV-vis spectra. The mechanism for the adsorption removal of thiol by [BIm]Cl/CuCl was discussed. It was found that the sulfur content in methyl tert -butyl ether (MTBE) could be reduced to lower than 5 μg/g via adsorptive distillation desulfurization process with [BIm]Cl/CuCl as adsorbent, and that significant deterioration in the desulfurization efficiency of adsorbent was not observed in a few recycling tests.

A newly developed, qualitative and quantitative method based on tunable synchrotron radiation vacuum ultraviolet photoionization time-of-flight mass spectrometry (SR-VUV-PI-TOFMS) and photoionization efficiency (PIE) curve simulation was applied for the online analysis of isomers and isobaric compounds in the gas phase of mainstream cigarette smoke. After blocking the particulate phase components by the Cambridge filter pad, a puff of fresh gas-phase cigarette smoke was immediately introduced into a vacuum ionization chamber through a heated capillary, then was photoionized, and analyzed by a TOF mass spectrometer. The PIE curves for the mass peaks up to m/z = 106 were measured between 8.0 and 10.7 eV. Some components could be directly identified by their discriminated ionization energies (IEs) on the PIE curve. By simulating the PIE curve with the sum of scaled absolute photoionization cross sections (PICSs), complex isomeric/isobaric compounds along with their mole fractions could be obtained when the best-fitting was realized between experimental and simulated PIE curves. A series of reported toxic compounds for quantification, such as 1,3-butadiene (m/z = 54), 1,3-cyclopentadiene (m/z = 66), benzene (m/z = 78), xylene (m/z = 106), 2-propenal (m/z = 56), acetone and propanal (m/z = 58), crotonaldehyde (m/z = 70), furan and isoprene (m/z = 68), were all found to have other isomers and/or isobaric compounds with considerable abundances. Some isomers have never been reported previously in cigarette smoke, like C5H6 isomers 1-penten-3-yne, 3-penten-1-yne, and 1-penten-4-yne at m/z = 66. Isomeric/isobaric compounds characterization for the mass peaks and mole fraction calculations were discussed in detail below 10.7 eV, an energy value covering several conventional used VUV light sources.

The objective of the study was the determination of the characteristics and the potential of remediation As polluted soil of three different biochars and straws. Results showed that biochar has better properties and microstructure for heavy metals remediation. Short-term incubation remediation experiments showed that biochars could decreased biological toxicity and mobility of As.

Vacuum ultraviolet (VUV) photoionization and dissociative photoionization of capecitabine and its metabolites, 5′‐deoxy‐5‐fiuorocytidine (5′‐DFCR) and 5′‐deoxy‐5‐ fluorouridine (5′‐DFUR), were investigated with infrared laser desorption/tunable synchrotron VUV photoionization mass spectrometry. Molecular ions (M+) with small amounts of fragments can be found for these compounds at relatively low photon energies, while more fragment ions would be produced by increasing the photon energies. (M−H2O)+, (base+H)+, (base+2H)+, (base+30)+, (base+60)+, and sugar moiety were proposed for these nucleoside drugs with similar backbones. Decomposition channels for the major fragments were discussed in detail. Moreover, ab initio calculations were introduced to study the dehydration pathways of three fluoro‐nucleosides. Corresponding appearance energies for the (M−H2O)+ ions were computed.

The minimum energy required for destratification of a source water reservoir is important to determine the design capacity of mixing system used to improve the source water quality. Taking Jinpen Reservoir in Xi’an, as a study case, the water volumes under different water levels of the reservoir were numerically calculated using the geometry data obtained with a RTK system. The total potential energy (PE) was determined by integrating the PE in each thin sub-layer over the water depth with density dependent on the water temperature. The average water temperature after complete mixing was calculated based on the heat exchange theory, and was consistent with the numerical result of temperature simulation. The difference of total potential energy before and after mixing was calculated for each month with the data of water temperature, water density and water volume. The minimum energy required for destratification increasing with the temperature gradient, was relatively high during the period from June to October, and reached a peak of 2412.92 kW·h in July.

Background : Gastric carcinoma is one of the most frequently occurring cancers. The aim of this research was to increase the detection efficiency of anti-p53 antibodies in the sera of patients with gastric carcinoma and to improve the diagnosis for patients with gastric carcinoma. Methods : We prepared phage-displayed peptide DO7 and established an enzyme-linked immunosorbent assay method to detect the anti-p53 antibodies. We detected the anti-p53 antibodies of 61 patients with gastric carcinoma using the method and our previous ELISA method assisted by the recombinant wild-type human p53 protein to detect the anti-p53 antibodies. We studied the correlation between the anti-p53 antibodies and the clinicopathological data including sex, age, carcinoembryonic antigen, tumor size, tumor TNM staging, and lymph-node status. Results : The anti-p53 antibodies positive rate for patients with gastric carcinoma was increased (31.1%, 19/61) through the combination of p53-ELISA and phage-ELISA. We found that the positive anti-p53 antibodies correlated significantly with tumor size ( P =0.047). The combination of the anti-p53 antibodies and carcinoembryonic antigen could improve the diagnosis for patients with gastric carcinoma. Conclusions : This approach indicated an increased anti-p53 antibodies positive rate for patients with gastric carcinoma and provided a useful marker for clinical diagnosis for patients with gastric carcinoma.

Singapore grouper iridovirus (SGIV) is an important pathogen isolated from grouper, Epinephelus tauvina, and characterized as a novel ranavirus. To better understand the function of viral structural genes involved in SGIV infection and virus-host interactions, a candidate gene, VP38 (ORF038L), was investigated in this study. SGIV VP38 was found to encode a 170-aa peptide containing an RGD motif, and it showed significant identity only to members of the genus Iridovirus, family Iridoviridae, except megalocytivirus. The VP38 gene was identified by temporal expression pattern analysis and drug inhibition assay as a late (L) gene. Immunofluorescence localization revealed that P38 was distributed predominately in the cytoplasm and that association of VP38 with viral factories increased at the late stage of SGIV infection. Consistent results from immunoelectron microscopy (IEM) and western blot analysis revealed that SGIV VP38 is a viral capsid protein. Furthermore, antibodies specific for SGIV VP38 exhibited substantial SGIV-neutralizing activity in vitro, suggesting that VP38 might play an important role in SGIV infectivity.