49 research outputs found

    Extremely large Lamb shift in a deep-strongly coupled circuit QED system with a multimode resonator

    Full text link
    We report experimental and theoretical results on the extremely large Lamb shift in a multimode circuit quantum electrodynamics (QED) system in the deep-strong coupling (DSC) regime, where the qubit-resonator coupling strength is comparable to or larger than the qubit and resonator frequencies. The system comprises a superconducting flux qubit (FQ) and a quarter-wavelength coplanar waveguide resonator (λ/4\lambda/4 CPWR) that are coupled inductively through a shared edge that contains a Josephson junction to achieve the DSC regime. Spectroscopy is performed around the frequency of the fundamental mode of the CPWR, and the spectrum is fitted by the single-mode quantum Rabi Hamiltonian to obtain the system parameters. Since the qubit is also coupled to a large number of higher modes in the resonator, the single-mode fitting does not provide the bare qubit energy but a value that incorporates the renormalization from all the other modes. We derive theoretical formulas for the Lamb shift in the multimode resonator system. As shown in previous studies, there is a cut-off frequency ωcutoff\omega_{\rm{cutoff}} for the coupling between the FQ and the modes in the CPWR, where the coupling grows as ωn\sqrt{\omega_n} for ωn/ωcutoff1\omega_n/\omega_{\rm{cutoff}}\ll 1 and decreases as 1/ωn1/\sqrt{\omega_n} for ωn/ωcutoff1\omega_n/\omega_{\rm{cutoff}}\gg 1. Here ωn\omega_n is the frequency of the nnth mode. The cut-off effect occurs because the qubit acts as an obstacle for the current in the resonator, which suppresses the current of the modes above ωcutoff\omega_{\rm{cutoff}} at the location of the qubit and results in a reduced coupling strength. Using our observed spectrum and theoretical formulas, we estimate that the Lamb shift from the fundamental mode is 82.3\% and the total Lamb shift from all the modes is 96.5\%.Comment: 16 pages, 4 figure

    Helicobacter pylori Infection and Gastroduodenal Disease : a Comparison of Endoscopic Findings, Histology, and Urease Test Data

    Get PDF
    To determine the prevalence and significance of Helicobacter pylori (H. pylori) infection, biopsies of the antral mucosa were obtained from 139 patients and 43 asymptomatic volunteers. The specimens were examined by hematoxylin-eosin staining and the urease test. The detection rate of H. pylori by histologic examination was 91.3% in patients with duodenal ulcer, 75.0% in those with combined duodenal and gastric ulcer, 63.6% in those with gastric ulcer, 22.9% in those with gastric carcinoma, 36.4% in those with gastric adenoma, 14.3% in those with gastric hyperplastic polyp, and 51.7% in those with gastritis, and the respective percentages detected by the urease test were 91.3%, 75.0%, 54.5%, 28.6%, 27.3%, 14.3%, and 44.8%. H. pylori was also detected in 10/43 (23.3%) asymptomatic healthy volunteers by histology and the urease test. The prevalence of H. pylori was significantly higher in the patients than in the asymptomatic healthy volunteers (p < 0.05). H. pylori was detected in 62.9% of patients with endoscopic erosive gastritis and in 97.9% of those with histologically proven chronic active gastritis. The urease test was positive in 77/82 patients who were histologically positive for the organism (sensitivity: 93.9%), and it was negative in 98/100 patients who were negative by histology (specificity: 98.0%). Thus, there was over 90% agreement between the urease test and histology. Our investigations showed that H. pylori was closely related to peptic ulcers and antral gastritis, and that the urease test provides a simple, rapid and accurate diagnosis of H. pylori infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

    Get PDF
    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Growth Patterns of Neonates Treated with Thermal Control in Neutral Environment and Nutrition Regulation to Meet Basal Metabolism

    No full text
    Little is known about the growth patterns of low birth weight neonates (&lt;2500 g) during standardized thermal control and nutrition regulation to meet basal metabolism requirements compared to those of non-low birth weight neonates (2500 g and above). We retrospectively identified 10,544 non-low birth weight and 681 low birth weight neonates placed in thermo-controlled incubators for up to 24 h after birth. All neonates were fed a 5% glucose solution 1 h after birth and breastfed every 3 h (with supplementary formula milk if applicable) to meet basal metabolism requirements. Maximum body-weight loss (%), percentage body-weight loss from birth to peak weight loss (%/day), and percentage body-weight gain from peak weight loss to day 4 (%/day) were assessed by multivariable linear regression. Overall, the growth curves showed a uniform J-shape across all birth weight categories, with a low mean maximum body-weight loss (1.9%) and incidence of neonatal jaundice (0.3%). The body-weight loss patterns did not differ between the two groups. However, low birth weight neonates showed significantly faster growth patterns for percentage body-weight gain: &beta; = 0.52 (95% confidence interval, 0.46 to 0.58). Under thermal control and nutrition regulation, low birth weight neonates might not have disadvantages in clinical outcomes or growth patterns

    Usefulness of Endoscopic Ultrasonography in Determining the Depth of Invasion and Indication for Endoscopic Treatment of Early Gastric Cancer

    Get PDF
    Introduction: Endoscopic ultrasonography (EUS) is a useful method for visualizing features of gastric cancer. However, a previously reported classification system tended to result in overstaging. We investigated the usefulness of EUS for evaluation of the depth of gastric cancer invasion and indications for endoscopic treatment. Methods: Accuracy of EUS for determining the depth of invasion and incidences of a positive basal margin were assessed in 235 patients who underwent endoscopic treatment or surgery for gastric cancer. The EUS-determined depth of invasion was classified its follows: EUS-M (lesion confined to sonographic layers 1 and 2); EUS-M/SM border (lesion with changes in sonographic layer 3 but no deeper than 1 min); EUS-SM (lesion with changes in sonographic layer 3 deeper than 1 mm); or EUS-AD (lesion with changes in sonographic layer 4 or 5). Results: Accuracy of EUS for determining the depth of invasion was as follows: EUS-M, 99% were M and SM1 lesions; EUS-M/SM border, 87% were M and SM1 lesions; EUS-SM, 91% were SM2 lesions; EUS-AD, 100% were muscularis propria or deeper lesions. There was no EUS-M or EUS-M/SM border lesion for which endoscopic treatment resulted in it positive basal margin. Conclusions: EUS is useful for accurately determining the depth of invasion of gastric cancer. When there are no endoscopically determined ulcerous changes. endoscopic treatment should be considered for EUS-M and EUS-M/SM border lesions, and EUS-SM lesions should be treated surgically

    Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy

    Get PDF
    Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compared prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. Twenty sites in the esophagus and 40 sites in the stomach were examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan), was used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei were visualized. In 9 of the 10 normal esophageal mucosa, cell membranes were visualized, and in 5 of the 10 esophageal cancers, cell membranes were visualized. In all normal gastric mucosa, nuclei and cell membranes were not visualized, but in 10 of the 20 gastric cancers, nuclei were visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy
    corecore