Observation and Manipulation of a Phase Separated State in a Charge Density Wave Material.

The 1T polytype of TaS2 has been studied extensively as a strongly correlated system. As 1T-TaS2 is thinned toward the 2D limit, its phase diagram shows significant deviations from that of the bulk material. Optoelectronic maps of ultrathin 1T-TaS2 have indicated the presence of nonequilibrium charge density wave phases within the hysteresis region of the nearly commensurate (NC) to commensurate (C) transition. We perform scanning tunneling microscopy on exfoliated ultrathin flakes of 1T-TaS2 within the NC-C hysteresis window, finding evidence that the observed nonequilibrium phases consist of intertwined, irregularly shaped NC-like and C-like domains. After applying lateral electrical signals to the sample, we image changes in the geometric arrangement of the different regions. We use a phase separation model to explore the relationship between electronic inhomogeneity present in ultrathin 1T-TaS2 and its bulk resistivity. These results demonstrate the role of phase competition morphologies in determining the properties of 2D materials.

Photocurrent Imaging of Multi-Memristive Charge Density Wave Switching in Two-Dimensional 1T-TaS2.

Transport studies of atomically thin 1T-TaS2 have demonstrated the presence of intermediate resistance states across the nearly commensurate (NC) to commensurate (C) charge density wave (CDW) transition, which can be further switched electrically. While this presents exciting opportunities for memristor applications, the switching mechanism could be potentially attributed to the formation of inhomogeneous C and NC domains. Here, we present combined electrical driving and photocurrent imaging of ultrathin 1T-TaS2 in a heterostructure geometry. While micron-sized CDW domains are seen upon cooling, electrically driven transitions are largely uniform, indicating that the latter likely induces true metastable CDW states, which we then explain by a free energy analysis. Additionally, we are able to perform repeatable and bidirectional switching across the intermediate states without changing sample temperature, demonstrating that atomically thin 1T-TaS2 can be further used as a robust and reversible multimemristor material for the first time.

Structure and control of charge density waves in two-dimensional 1T-TaS2.

The layered transition metal dichalcogenides host a rich collection of charge density wave phases in which both the conduction electrons and the atomic structure display translational symmetry breaking. Manipulating these complex states by purely electronic methods has been a long-sought scientific and technological goal. Here, we show how this can be achieved in 1T-TaS2 in the 2D limit. We first demonstrate that the intrinsic properties of atomically thin flakes are preserved by encapsulation with hexagonal boron nitride in inert atmosphere. We use this facile assembly method together with transmission electron microscopy and transport measurements to probe the nature of the 2D state and show that its conductance is dominated by discommensurations. The discommensuration structure can be precisely tuned in few-layer samples by an in-plane electric current, allowing continuous electrical control over the discommensuration-melting transition in 2D.

A comparison between capsule endoscopy and double balloon enteroscopy using propensity score-matching analysis in patients with previous obscure gastrointestinal bleeding.

BACKGROUND: Recently, diagnosis of obscure gastrointestinal bleeding (OGIB) has improved greatly due to introduction of capsule endoscopy (CE) and double balloon enteroscopy (DBE). However, the efficacy of CE over DBE in patients with previous OGIB remains unclear. This study aimed to compare, in terms of diagnostic yield, the efficacy of DBE with that of CE in patients with previous OGIB. PATIENTS AND METHODS: We enrolled 223 consecutive patients with previous OGIB who were treated between May 2007 and March 2012. We retrospectively evaluated the respective diagnostic yields of CE and DBE in patients with previous OGIB using propensity score-matching analysis. We compared the diagnostic yield of CE with that of DBE. RESULTS: The diagnostic yields were 41.9% in DBE group and 11.6% in CE group, respectively (p < .01). On logistic regression analysis, DBE was significantly superior to CE after matching (Odds ratio [OR], 4.25; 95% confidence interval [CI], 1.43-12.6; p < .01), even after adjustment for propensity score (OR, 5.65; 95% CI, 1.56?20.5; p < .01). CONCLUSIONS: Our results indicate that DBE might be more useful and perhaps safer than CE in achieving a positive diagnosis in patients with previous OGIB.

Theory of Enhanced Interlayer Tunneling in Optically Driven High-T_{c} Superconductors.

Motivated by recent pump-probe experiments indicating enhanced coherent c-axis transport in underdoped YBCO, we study Josephson junctions periodically driven by optical pulses. We propose a mechanism for this observation by demonstrating that a parametrically driven Josephson junction shows an enhanced imaginary part of the low-frequency conductivity when the driving frequency is above the plasma frequency, implying an effectively enhanced Josephson coupling. We generalize this analysis to a bilayer system of Josephson junctions modeling YBCO. Again, the Josephson coupling is enhanced when the pump frequency is blue detuned to either of the two plasma frequencies of the material. We show that the emergent driven state is a genuine, nonequilibrium superconducting state, in which equilibrium relations between the Josephson coupling, current fluctuations, and the critical current no longer hold.

Prediction of Poor Response to Modified Neuroleptanalgesia with Midazolam for Endoscopic Submucosal Dissection for Esophageal Squamous Cell Carcinoma.

BACKGROUND/AIMS: Modified neuroleptanalgesia (m-NLA) with midazolam is often used for sedation and analgesia during endoscopic submucosal dissection (ESD) for gastrointestinal neoplasia. However, interruption due to poor response to midazolam is often experienced during ESD for esophageal squamous cell carcinoma (ESCC) because most patients with ESCC have a history of heavy alcohol intake. We examined the incidence and risk factors for poor response to m-NLA with midazolam and pethidine hydrochloride. METHODS: This retrospective cross-sectional study was conducted at a single institution. Between April 2007 and July 2013, 151 patients with superficial ESCC who underwent ESD under sedation using m-NLA with midazolam and pethidine hydrochloride were enrolled. Poor response to sedation was defined as the use of a second drug when Ramsay Sedation Score 1-2. RESULTS: Poor response to sedation occurred in 66.2% patients. Most cases of poor response were controlled by using additional flunitrazepam. Multivariate logistic regression analysis showed that cumulative alcohol intake and major specimen size were independent risk factors for poor response to sedation (OR 3.63, 95% CI 1.20-10.99, and OR 3.23, 95% CI 1.26-8.25). CONCLUSION: Our study indicated that cumulative alcohol intake and major specimen size were associated with poor response to m-NLA with midazolam and pethidine hydrochloride.

Comparison of Risk Factors Between Small Intestinal Ulcerative and Vascular Lesions in Occult Versus Overt Obscure Gastrointestinal Bleeding.

BACKGROUND AND AIMS: The detailed risk factors such as bleeding pattern, comorbidities, and medication usage of patients with obscure gastrointestinal bleeding (OGIB) are largely unknown. We evaluated the risk factors related to ulcerative and vascular lesions of the small intestine diagnosed by capsule endoscopy or balloon-assisted endoscopy in OGIB cases. METHODS: We retrospectively evaluated 390 OGIB cases (occult, n = 101; overt, n = 289) in our hospital between January 2005 and March 2011 using univariate and multivariate logistic regression analyses to determine the related risk factors. RESULTS: In occult (n = 36) and overt (n = 120) OGIB cases, some lesions were detected in the small intestine. Ulcerative and vascular lesions were detected in both occult (n = 25, 69.4 %; n = 8, 22.2 %, respectively) and overt (n = 57, 47.5 %; n = 39, 32.5 %, respectively) cases. For ulcerative lesions, non-steroidal anti-inflammatory drugs were identified as a risk factor in overt cases [odds ratio (OR) 2.974, 95 % confidence interval (CI) 1.522-5.809, P = 0.001]. For vascular lesions, lowest hemoglobin level (OR 0.634, 95 % CI 0.422-0.953, P = 0.028) and hematologic disease (OR 8.575, 95 % CI 1.076-68.309, P = 0.042) were identified as risk factors in occult cases, whereas hemodialysis (OR 3.71, 95 % CI 1.315-10.467, P = 0.013) was identified in overt cases. Additionally, liver cirrhosis was noted as a risk factor in both occult (OR 7.453, 95 % CI 1.213-45.773, P = 0.013) and overt (OR 4.900, 95 % CI 2.099-11.443, P < 0.001) OGIB cases. CONCLUSION: There are differences in risk factors related to ulcerative versus vascular lesions in the small intestine in occult and overt OGIB cases. Differences were seen in both medication usage and comorbidities.

Experimental evidence for a Bragg glass density wave phase in a transition-metal dichalcogenide.

Analysis of the spatial dependence of current-voltage characteristics obtained from scanning tunneling microscopy experiments indicates that the charge density wave (CDW) occurring in NbSe_{2} is subject to locally strong pinning by a non-negligible density of defects, but that on the length scales accessible in this experiment the material is in a "Bragg glass" phase where dislocations and antidislocations occur in bound pairs and free dislocations are not observed. An analysis based on a Landau theory is presented showing how a strong local modulation may produce only a weak long range effect on the CDW phase.

Safe transection of aberrant arteries associated with pulmonary sequestrations.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) lobectomy is increasingly used for pulmonary sequestration; however, there are few descriptions of safe handling of the aberrant artery. Here we clarify the safe handling of an aberrant artery using a clinical review and an experimental model. METHODS: We retrospectively reviewed the records of patients who underwent lobectomy for pulmonary sequestration with aberrant arteries at the Nippon Medical School between January 2008 and December 2010. This was supplemented by an experimental pressure test using vessels obtained from pigs. RESULTS: We identified four patients with aberrant arteries that were successfully occluded via either stapling. In the experimental model, we divided pig vessels into small-diameter (S) and large-diameter (L) groups. The 1.0-mm-high staples were stronger in the S group than in the L group (p = 0.028). In the L group, the 2.0-mm-high staples were stronger than the 1.0-mm staples (p = 0.015). Leakage from the staple line was associated with a poorer B-shape of inserted staples. CONCLUSIONS: The techniques described in this report are useful in successful minimally invasive transection of an aberrant artery (other than very thin vessels) when resecting a pulmonary sequestration by stapler only. A detailed investigation should be performed to determine the most appropriate stapler or cartridge.

Macroscopic tunneling probe of Moiré spin textures in twisted CrI3.

Various noncollinear spin textures and magnetic phases have been predicted in twisted two-dimensional CrI3 due to competing ferromagnetic (FM) and antiferromagnetic (AFM) interlayer exchange from moiré stacking-with potential spintronic applications even when the underlying material possesses a negligible Dzyaloshinskii-Moriya or dipole-dipole interaction. Recent measurements have shown evidence of coexisting FM and AFM layer order in small-twist-angle CrI3 bilayers and double bilayers. Yet, the nature of the magnetic textures remains unresolved and possibilities for their manipulation and electrical readout are unexplored. Here, we use tunneling magnetoresistance to investigate the collective spin states of twisted double-bilayer CrI3 under both out-of-plane and in-plane magnetic fields together with detailed micromagnetic simulations of domain dynamics based on magnetic circular dichroism. Our results capture hysteretic and anisotropic field evolutions of the magnetic states and we further uncover two distinct non-volatile spin textures (out-of-plane and in-plane domains) at ≈1° twist angle, with a different global tunneling resistance that can be switched by magnetic field.

Descending necrotizing mediastinitis associated with Lactobacillus plantarum.

BACKGROUND: Descending necrotizing mediastinitis (DNM), a severe infection with a high fatality rate, develops in mediastinal spaces due mainly to deep cervical abscesses. The majority of causative microbes of DNM are Streptococci and oral anaerobes. DNM associated with Lactobacillus-infection is rather rare. CASE PRESENTATION: A 69-year-old male with an unremarkable past medical history was referred to our hospital for surgical resection of advanced laryngeal cancer. Full examination revealed a neck abscess and DNM with a background of untreated diabetes mellitus. Initially, he was treated with meropenem. However, Lactobacillus plantarum was isolated from surgical drainage of a mediastinal abscess. Despite using antibiotics capable of eradicating all isolates with susceptibilities not differing significantly from those of the neck and mediastinal abscesses, we attributed DNM to the L. plantarum detected only in the mediastinal abscess. After DNM treatment, he underwent total pharyngolaryngectomy with bilateral neck dissection followed by reconstruction using free jejunum. He was discharged fully recovered. CONCLUSION: We concluded that L. plantarum as the sole cause of the mediastinal abscess in the present case cannot be ruled out. As the number of immunocompromised patients increases, we should be cautious regarding this "familiar" microbe.

Impact of the first surge of the coronavirus disease pandemic on general thoracic surgery practices in Kanagawa: a questionnaire survey by the Kanagawa General Thoracic Surgical Study Group.

OBJECTIVES: The first surge in severe acute respiratory syndrome coronavirus 2 infection had a significant impact on health care institutions. Understanding how the pandemic affected general thoracic surgery would provide valuable data for establishing a health care protocol for upcoming surges. METHODS: A questionnaire survey on coronavirus disease-related patient statistics and health care was conducted between February 2020 and June 2020 across 14 facilities affiliated with the Kanagawa General Thoracic Surgery Study Group. RESULTS: The average number of newly referred patients from February to June 2020 was 65% of that during the same period in 2019. Six facilities placed restrictions on medical care services, among which four restricted surgeries. At all institutions and those placed on surgical restriction, the total number of surgeries under general anesthesia was 92% and 78%, the total number of primary lung cancers was 94% and 86%, and the total number of surgeries for pneumothorax was 71% and 77% of that in the preceding year, respectively. Infection control and insufficient resources of the medical material were the most influential factors impacting the medical institutions' decision to restrict the services provided. CONCLUSIONS: Restrictions on surgery had a significant impact on the care provided by general thoracic surgery departments. To avoid patient inconvenience, establishing a collaborative system that refers patients to operational medical institutions in case of medical treatment restrictions may be useful.

Floquet prethermalization and Rabi oscillations in optically excited Hubbard clusters.

We study the properties of Floquet prethermal states in two-dimensional Mott-insulating Hubbard clusters under continuous optical excitation. With exact-diagonalization simulations, we show that Floquet prethermal states emerge not only off resonance, but also for resonant excitation, provided a small field amplitude. In the resonant case, the long-lived quasi-stationary Floquet states are characterized by Rabi oscillations of observables such as double occupation and kinetic energy. At stronger fields, thermalization to infinite temperature is observed. We provide explanations to these results by means of time-dependent perturbation theory. The main findings are substantiated by a finite-size analysis.

Continuous warfarin administration versus heparin bridging therapy in post colorectal polypectomy haemorrhage: a study protocol for a multicentre randomised controlled trial (WHICH study).

BACKGROUND: Endoscopic removal of colorectal adenoma is considered an effective treatment for reducing the mortality rates associated with colorectal cancer. Warfarin, a type of anticoagulant, is widely used for the treatment and prevention of thromboembolism; however, bleeding may increase with its administration after polypectomy. In recent times, a high incidence of bleeding after endoscopic polypectomy has been reported in patients receiving heparin bridge therapy. However, previous studies have not compared the bleeding rate after endoscopic colorectal polypectomy between patients who continued with anticoagulant therapy and those who received heparin bridge therapy. We hypothesised that endoscopic colorectal polypectomy under the novel treatment with continuous warfarin is not inferior to endoscopic colorectal polypectomy under standard treatment with heparin bridge therapy with respect to the rate of postoperative bleeding. This study aims to compare the efficacy of endoscopic colorectal polypectomy with continuous warfarin administration and endoscopic colorectal polypectomy with heparin bridge therapy with respect to the rate of postoperative bleeding. METHODS: We will conduct a prospective multicentre randomised controlled non-inferiority trial of two parallel groups. We will compare patients scheduled to undergo colorectal polypectomy under anticoagulant therapy with warfarin. There will be 2 groups, namely, a standard treatment group (heparin bridge therapy) and the experimental treatment group (continued anticoagulant therapy). The primary outcome measure is the rate of postoperative bleeding. On the contrary, the secondary outcomes include the rate of cumulative bleeding, rate of overt haemorrhage (that does not qualify for the definition of haemorrhage after endoscopic polypectomy), incidence of haemorrhage requiring haemostasis during endoscopic polypectomy, intraoperative bleeding during endoscopic colorectal polypectomy requiring angiography, abdominal surgery and/or blood transfusion, total rate of bleeding, risk factors for postoperative bleeding, length of hospital stay, incidence of thromboembolism, prothrombin time-international ratio (PT-INR) 28 days after the surgery, and incidence of serious adverse events. DISCUSSION: The results of this randomised controlled trial will provide valuable information for the standardisation of management of anticoagulants in patients scheduled to undergo colorectal polypectomy. TRIAL REGISTRATION: UMIN-CTR UMIN000023720 . Registered on 22 August 2016.

Early extubation in current valve surgery requiring long cardiopulmonary bypass: Benefits and predictive value of preoperative spirometry.

BACKGROUND: Early extubation (EEx) after cardiac surgery has been essentially studied in patients with short cardiopulmonary bypass (CPB). Whether preoperative spirometry can predict EEx remains controversial. OBJECTIVES: To investigate whether EEx can be a goal and predicted by preoperative spirometry in valve surgery requiring long CPB. METHODS: Nonemergent consecutive 210 patients who underwent valve surgery from January 2014 to August 2019 were investigated retrospectively. RESULTS: EEx (<8 h) was achieved in 93 (44.3%) patients without increasing adverse events. Patients with EEx had shorter ICU and hospital stays than those without EEx. Multivariate analysis showed that higher estimated glomerular filtration rate and mitral valve repair were significant protective factors for EEx. Conversely, moderate and severe chronic obstructive pulmonary disease defined by spirometry, longer operation, CPB, and aortic cross-clamp time were significant risk factors. CONCLUSIONS: EEx should be the goal in current valve surgery. Preoperative spirometry is a significant predictor.

Epigenetic alteration of the Wnt inhibitory factor-1 promoter occurs early in the carcinogenesis of Barrett's esophagus.

The role of Wnt antagonists in the carcinogenesis of esophageal adenocarcinoma (EAC) remains unclear. We hypothesized that downregulation of the Wnt inhibitory factor-1 (WIF-1) might be involved in the neoplastic progression of Barrett's esophagus (BE). We analyzed the DNA methylation status of the WIF-1 promoter in normal, preneoplastic, and neoplastic samples from BE patients and in EAC cell lines. We investigated the role of WIF-1 on EAC cell growth and the chemosensitization of the cells to cisplatin. We found that silencing of WIF-1 correlated with promoter hypermethylation. EAC tissue samples showed higher levels of WIF-1 methylation compared to the matched normal epithelium. In addition, we found that WIF-1 hypermethylation was more frequent in BE samples from patients with EAC than in BE samples from patients who had not progressed to EAC. Restoration of WIF-1 in cell lines where WIF-1 was methylation-silenced resulted in growth suppression. Restoration of WIF-1 could sensitize the EAC cells to the chemotherapy drug cisplatin. Our results suggest that silencing of WIF-1 through promoter hypermethylation is an early and common event in the carcinogenesis of BE. Restoring functional WIF-1 might be used as a new targeted therapy for the treatment of this malignancy.

Prognostic effect of incompletely lobulated fissures in p-Stage I non-small-cell lung cancer.

OBJECTIVES: Division of incompletely lobulated fissures is often performed during surgical resection of non-small-cell lung cancer (NSCLC); however, the effect of lobulation on tumour recurrence is unclear. This study aimed to assess the prognostic effect of lobulation in patients with NSCLC according to their preoperative and operative findings. METHODS: A retrospective study of patients with p-stage I NSCLC who underwent lobectomy was conducted between April 2008 and April 2016. A receiver operating characteristic curve of the number of stapling cartridges was constructed to determine the optimal cut-off value. Patients who underwent division of the interlobar fissure using 2 or more stapling cartridges (H group) were compared with those who did not undergo division of the interlobar fissure or who underwent division of the interlobar fissure using only 1 cartridge (L group). RESULTS: The study included 85 patients, and of these patients, 46 were included in the L group and 39 in the H group. Survival analysis showed better disease-specific survival (P = 0.0135) and disease-free survival (P = 0.0412) in the L group. Cox regression analysis showed better disease-specific survival in patients who underwent division of the interlobar fissure with few stapler cartridges than in those who underwent division with more stapler cartridges (P = 0.021). CONCLUSIONS: The extent and status of incompletely lobulated fissures are significant risk factors for disease-specific survival in patients with resected p-stage I NSCLC.

Communication Site Ligation and Polyglycolic Acid Sheet Use for the Treatment of Hydrothorax in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis.

INTRODUCTION: Hydrothorax due to pleuroperitoneal communication (PPC) can occur in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). We report our experiences of the safety and efficacy of the treatment of four patients with a novel video-assisted thoracoscopy method. METHODS: Single-port video-assisted thoracoscopic surgery (VATS) was performed with a mini-thoracotomy of 5 cm in length. The PPC site was identified on the diaphragm and ligated using an endoscopic loop. The diaphragm was then covered using a polyglycolic acid (PGA) sheet, over which adhesive chemicals (OK432 and tetracycline) were sprayed. RESULTS: We assessed the efficacy of our approach in four patients (one female and three males) aged 42-74 years (mean: 62.0 years). The hydrothoraxes were right sided in all the patients. The mean operation and postoperative drainage times were 92.5 min and 3.0 days, respectively. The hydrothoraxes did not recur in any patient during follow-up periods of 8-46 months. CONCLUSION: Our suture- and staple-free technique is not only easy to perform but also appears to be safe and effective for the management of hydrothorax in patients receiving CAPD. Larger scale studies are now indicated.

Wnt inhibitory factor-1 gene transfer inhibits melanoma cell growth.

Silencing of Wnt antagonists with aberrant activation of Wnt signaling is a common phenomenon in various human cancers. Wnt inhibitory factor-1 (WIF-1) is a secreted antagonist of Wnt signaling and acts through direct binding to Wnt in the extracellular space. In this study, we tried to illuminate the impact of WIF-1 gene expression in melanoma with WIF-1 silencing by in vitro and in vivo studies. We restored the expression of WIF-1 by nonviral gene transfer with a pcDNA3.1 vector. We demonstrated inhibition of melanoma cell growth after WIF-1 restoration in colony formation and proliferation assays in vitro. In addition, the inhibitory effect was related to downregulation of Wnt signaling, which was demonstrated at both the transcriptional and translational levels. Furthermore, by using a xenograft mouse model, we confirmed the effect of WIF-1 expression in suppressing tumor growth by inhibition of Wnt signaling in vivo. Our results suggest the potential for further application of WIF-1 gene therapy in melanoma with WIF-1 silencing.