Abstract
We report NMR experiments on heavily electron-doped Fe-based superconductor in comparison with the results on the parent Fe-based compounds. The typical parent Fe-based compound LaFe(As
1-
x
...′
P
x
′
)O exhibits the re-emergent antiferromagnetic (AFM) order at
x
′ ~ 0.6 (AFM2) separated from the parent AFM order at
x
′ =0 (AFM1). Systematic
31
P-NMR study on Sr
4
Sc
2
O
6
Fe
2
(As
1−
x
P
x
)
2
(SrSc42622), which has local lattice parameters of iron-pnictogen (Fe
Pn
) layer similar to the series of LaFe(As
1−
x
′
/P
x
′
)O, also revealed that the presence of AFM1 order is universal for most of parent Fe-based compounds. In contrast, the static AFM2 order was absent in this series, however, the dynamical low-energy AFM spin fluctuations are enhanced at around
x
~ 0.8, indicating that the onset of the static AFM2 is quite sensitive to the local lattice parameters of Fe
Pn
layer. In order to elucidate the further universality and diversity, we have carried out
77
Se-NMR measurement on Li
x
(NH
3
)
y
Fe
2−
δ
Se
2
(
T
c
= 44 K) in heavily electron-doped regime. Although the spin fluctuations at low energies does not significantly develops upon cooling, the moderate spin fluctuations were extracted at high temperatures from comparison of the temperature (
T
) dependences of Knight shift and nuclear relaxation rate (1/
T
1
T
). We discuss the universality and diversity of the relationship between the
T
c
and the characteristics of the spin fluctuations in the Fe-based compounds from a microscopic point of the NMR measurements.
Our previous study by two dimension in real space and three dimension in velocity space-particle in cell model shows that the curvature of the plasma meniscus causes the beam halo in the negative ion ...sources. The negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. The purpose of this study is to verify this mechanism with the full 3D model. It is shown that the above mechanism is essentially unchanged even in the 3D model, while the fraction of the beam halo is significantly reduced to 6%. This value reasonably agrees with the experimental result.
Background Optical coherence tomography (OCT) is a cross-sectional, high-resolution imaging modality that has been shown to accurately differentiate esophageal specialized intestinal metaplasia (SIM) ...from gastric cardia at the squamocolumnar junction (SCJ) and diagnose high-grade dysplasia and intramucosal carcinoma in patients with SIM. The clinical utility of OCT has been limited, however, by its inability to acquire images over large areas. Objective The aim of this study was to use recently developed high-speed OCT technology, termed optical frequency domain imaging (OFDI), and a new balloon-centering catheter (2.5 cm diameter) to demonstrate the feasibility of large area, comprehensive optical microscopy of the entire distal esophagus (∼6.0 cm) in patients. Design A pilot feasibility study. Setting Massachusetts General Hospital. Patients Twelve patients undergoing routine EGD. Results Comprehensive microscopy of the distal esophagus was successfully performed in 10 patients with the OFDI system and balloon catheter. There were no complications resulting from the imaging procedure. Volumetric data sets were acquired in less than 2 minutes. OFDI images at the SCJ showed a variety of microscopic features that were consistent with histopathologic findings, including squamous mucosa, cardia, SIM with and without dysplasia, and esophageal erosion. Limitations Inability to obtain direct correlation of OFDI data and histopathologic diagnoses. Conclusions Comprehensive volumetric microscopy of the human distal esophagus was successfully demonstrated with OFDI and a balloon-centering catheter, providing a wealth of detailed information about the structure of the esophageal wall. This technique will support future studies to compare OFDI image information with histopathologic diagnoses.
Summary
Although surgery is traditionally the standard of care for esophageal cancer, esophagectomy carries significant morbidity. Alternative endoscopic therapies are needed for patients who are not ...candidates for conventional treatment. The objective of this study is to assess the safety, efficacy, and tolerability of spray cryotherapy of esophageal adenocarcinoma. This study includes patients with esophageal adenocarcinoma who had failed or were not candidates for conventional therapy enrolled retrospectively and prospectively in an open-label registry and patients in a retrospective cohort from 11 academic and community practices. Endoscopic spray cryotherapy was performed until biopsy proven local tumor eradication or until treatment was halted due to progression of disease, patient withdrawal or comorbidities. Eighty-eight patients with esophageal adenocarcinoma (median age 76, 80.7% male, mean length 5.1 cm) underwent 359 treatments (mean 4.4 per patient). Tumor stages included 39 with T1a, 25 with T1b, 9 with unspecified T1, and 15 with T2. Eighty-six patients completed treatment with complete response of intraluminal disease in 55.8%, including complete response in 76.3% for T1a, 45.8% for T1b, 66.2% for all T1, and 6.7% for T2. Mean follow-up was 18.4 months. There were no deaths or perforations related to spray cryotherapy. Strictures developed in 12 of 88 patients (13.6%) but were present before spray cryotherapy in 3 of 12. This study suggests that endoscopic spray cryotherapy is a safe, well-tolerated, and effective treatment option for early esophageal adenocarcinoma.
Background & Aims: Optical coherence tomography (OCT) is an imaging technique that produces high-resolution cross-sectional images in vivo. The aim of this study was to establish the sensitivity and ...specificity of OCT for diagnosing specialized intestinal metaplasia (SIM). Methods: OCT was used to image the stomach and esophagus of 121 patients. A total of 288 biopsycorrelated OCT images were acquired. OCT criteria for SIM were formulated by analyzing 75 images of SIM. The SIM image criteria were retrospectively tested by applying them to images of gastric, squamous, SIM, and cardiac epithelium. The criteria were then tested prospectively to determine the sensitivity and specificity of OCT for diagnosing SIM. Results: OCT images of SIM are characterized by (1) absence of the layered structure of normal squamous epithelium and the vertical “pit and crypt” morphology of gastric mucosa, (2) disorganized architecture with inhomogeneous tissue contrast and an irregular mucosal surface, and (3) presence of submucosal glands. These criteria were 100% sensitive and 93% specific for SIM when applied retrospectively and 97% sensitive and 92% specific when tested prospectively. Conclusions: OCT is highly sensitive and specific for SIM and may aid in the diagnosis and surveillance of this preneoplastic lesion.
Objectives
This study aimed to investigate whether inflammation affects the outcome of swallowing ability to improve treatment for sarcopenic dysphagia.
Design
A retrospective observational cohort ...study was performed using data from the Japanese sarcopenic dysphagia database.
Setting
The database was constructed using data from 19 hospitals and one home visiting rehabilitation team.
Participants
Patients with sarcopenic dysphagia with measurements of C-reactive protein (CRP) and serum albumin (Alb) were included.
Measurements
Patients were assigned to two groups using CRP, Alb, and the Japanese modified Glasgow Prognostic Score (mGPS). The Food Intake LEVEL Scale (FILS) was measured at the times of admission and follow-up (FILS follow-up) to assess swallowing function.
Results
A total of 197 patients were included. Mean or median values of each parameter were as follows: age: 83.8±8.7, Alb: 3.2 ± 0.6 g/dL, CRP: 8.0 3.0, 29.0 mg/L, mGPS: 1 1–2, FILS: 7 6–8, FILS follow-up: 8 7–8, and duration of follow-up: 57.0 27.0, 85.0 days. The FILS score at follow-up was significantly lower in the high CRP group (≥ 5.0 mg/L) than in the low CRP group (< 5.0 mg/L) (p = 0.01). Further, the FILS score at follow-up was significantly lower in the high mGPS group (class; 2) than in the low mGPS group (class; 0 and 1) (p = 0.03). In the multiple linear regression analyses without FILS at baseline, CRP and mGPS were independent risk factors for FILS follow-up. When FILS at baseline was entered, CRP and mGPS were not an independent risk factors for FILS follow-up.
Conclusions
Inflammation could modify the outcome of the patients with sarcopenic dysphagia. Inflammation may be an important risk factor in evaluating patients with sarcopenic dysphagia.
The epidermal growth factor (EGF) pathway is important in esophageal adenocarcinoma (EAC) tumorigenesis. We hypothesized that the EGF A61G homozygous variant genotype (GG) is (a) both a risk and poor ...prognostic factor for EAC and (b) associated with higher EGF serum levels in individuals with gastroesophageal reflux disease (GERD).
Using unconditional logistic regression, we compared EGF A61G in 312 EAC cases and 447 GERD-free controls, adjusting for age, gender, smoking history, and healthy adult body mass index. Using the method of Kaplan and Meier, log-rank tests, and Cox proportional hazard models, we correlated EGF A61G with overall and failure-free survival in the EAC cases. Serum EGF levels and EGF genotype (G/G versus others) were correlated in 144 GERD patients using Wilcoxon rank sum tests.
The EGF A61G G/G genotype conferred increased EAC risk, with an adjusted odds ratio of 1.81 (95% confidence interval, 1.2-2.7), and was even higher in the subgroup of EAC patients with concurrent Barrett's esophagus (adjusted odds ratio, 2.18; 95% confidence interval, 1.3-3.7). However, EGF A61G was not associated with a more aggressive phenotype or prognosis in EAC patients. Higher serum EGF levels were found in GERD patients carrying G/G compared with A/A or A/G (P = 0.03, Wilcoxon rank sum test).
The EGF A61G G/G genotype is associated with a near 2-fold greater risk of EAC. The G/G allele was also associated with higher EGF levels in tumor-free patients with GERD. EGF genotyping can potentially identify high-risk patients with GERD and Barrett's metaplasia who might benefit from increased surveillance.
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