Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer

Magnetic skyrmions have fast evolved from a novelty, as a realization of topologically protected structure with particle-like character, into a promising platform for new types of magnetic storage. Significant engineering progress was achieved with the synthesis of compounds hosting room-temperature skyrmions in magnetic heterostructures, with the interfacial Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation. Here we report findings of ultrathin skyrmion formation in a few layers of SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer. Measurement of the topological Hall effect (THE) reveals a robust stability of skyrmions in this platform, judging from the high value of the critical field 1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film proves the rumpling of the Ru-O plane to be the source of inversion symmetry breaking and DMI. First-principles calculations based on the structure obtained from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the main source of skyrmion robustness. These features promise a few-layer SRO to be an important new platform for skyrmionics, without the necessity of introducing the capping layer to boost the spin-orbit coupling strength artificially.Comment: Supplementary Information available upon reques

Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer

Magnetic skyrmions have fast evolved from a novelty, as a realization of topologically protected structure with particle-like character, into a promising platform for new types of magnetic storage. Significant engineering progress was achieved with the synthesis of compounds hosting room-temperature skyrmions in magnetic heterostructures, with the interfacial Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation. Here we report findings of ultrathin skyrmion formation in a few layers of SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer. Measurement of the topological Hall effect (THE) reveals a robust stability of skyrmions in this platform, judging from the high value of the critical field 1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film proves the rumpling of the Ru-O plane to be the source of inversion symmetry breaking and DMI. First-principles calculations based on the structure obtained from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the main source of skyrmion robustness. These features promise a few-layer SRO to be an important new platform for skyrmionics, without the necessity of introducing the capping layer to boost the spin-orbit coupling strength artificially.Comment: Supplementary Information available upon reques

Fatal Delayed Coronary Artery Perforation After Coronary Stent Implantation

Most type I and II perforations are predominately caused by hydrophilic and stiff wires, often presented in the delayed form, and do not require pericardial drainage or surgical interventions. However, we report a type III delayed coronary artery perforation at the site of stent implantation after intervention without any evidence of immediate perforations. To the best of our knowledge, this is the first case report of angiographic documentation and treatment of delayed coronary perforation at the site of stent, presented as a cardiac arrest

No axillary surgical treatment for lymph node-negative patients after ultra-sonography [NAUTILUS]: protocol of a prospective randomized clinical trial

Abstract Background Following sentinel lymph node biopsy (SLNB), the axillary recurrence rate is very low although SLNB has a false-negative rate of 5–10%. In the ACOSOG Z0011 trial, non-sentinel positive-lymph nodes were found in more than 20% of the axillary dissection group; the SLNB only group did not have a higher axillary recurrence rate. These findings raised questions about the direct therapeutic effect of the SLNB. SLNB has post-surgical complications including lymphedema. Considering advances in imaging modalities and adjuvant therapies, the role of SLNB in early breast cancer needs to be re-evaluated. Methods The NAUTILUS trial is a prospective multicenter randomized controlled trial involving clinical stage T1–2 and N0 breast cancer patients receiving breast-conserving surgery. Axillary ultrasound is mandatory before surgery with predefined imaging criteria for inclusion. Ultrasound-guided core needle biopsy or needle aspiration of a suspicious node is allowed. Patients will be randomized (1:1) into the no-SLNB (test) and SLNB (control) groups. A total of 1734 patients are needed, considering a 5% non-inferiority margin, 5% significance level, 80% statistical power, and 10% dropout rate. All patients in the two groups will receive ipsilateral whole-breast radiation according to a predefined protocol. The primary endpoint of this trial is the 5-year invasive disease-free survival. The secondary endpoints are overall survival, distant metastasis-free survival, axillary recurrence rate, and quality of life of the patients. Discussion This trial will provide important evidence on the oncological safety of the omission of SLNB for early breast cancer patients undergoing breast-conserving surgery and receiving whole-breast radiation, especially when the axillary lymph node is not suspicious during preoperative axillary ultrasound. Trial registration ClinicalTrials.gov, NCT04303715 . Registered on March 11, 2020

Practice Pattern of Gastroenterologists for the Management of GERD Under the Minimal Influence of the Insurance Reimbursement Guideline: A Multicenter Prospective Observational Study

The objective of the study was to document practice pattern of gastroenterologists for the management of gastroesophageal reflux disease (GERD) under the minimal influence of the insurance reimbursement guideline. Data on management for 1,197 consecutive patients with typical GERD symptoms were prospectively collected during 16 weeks. In order to minimize the influence of reimbursement guideline on the use of proton pump inhibitors (PPIs), rabeprazole was used for the PPI treatment. A total of 861 patients (72%) underwent endoscopy before the start of treatment. PPIs were most commonly prescribed (87%). At the start of treatment, rabeprazole 20 mg daily was prescribed to 94% of the patients who received PPI treatment and 10 mg daily to the remaining 6%. At the third visits, rabeprazole 20 mg daily was prescribed to 70% of those who were followed and 10 mg daily for the remaining 30%. Continuous PPI treatment during the 16-week period was performed in 63% of the study patients. In conclusion, a full-dose PPI is preferred for the initial and maintenance treatment of GERD under the minimal influence of the insurance reimbursement guideline, which may reflect a high proportion of GERD patients requiring a long-term treatment of a full-dose PPI

YM155 Induces EGFR Suppression in Pancreatic Cancer Cells

YM155, which inhibits the anti-apoptotic protein survivin, is known to exert anti-tumor effects in various cancers, including prostate and lung cancer. However, there are few reports describing the inhibitory effect of YM155 on human pancreatic cancers that highly express survivin. Here, we tested the effects of YM155 on a variety of cancer cell lines, including pancreatic cancer cells. We found that YM155 exerts an anti-proliferative effect in pancreatic cancer cells, inducing cell death through suppression of XIAP (X-linked inhibitor of apoptosis) as well as survivin without affecting the anti-apoptotic proteins Bcl-xL or Mcl-1. YM155 also inhibited tumor growth in vivo, reducing the size of pancreatic cancer cell line MIAPaCa-2 xenografts by 77.1% on day 31. Western blot analyses further showed that YM155 downregulated phosphoinoside 3-kinase (PI3K) expression and reduced the levels of phosphorylated (activated) extracellular signal-regulated kinase (ERK) and STAT3 (signal transducer and activator of transcription 3) in PANC-1 cells. Interestingly, we also found that YM155 downregulated the epidermal growth factor receptor (EGFR) in various cancer cell lines and induced the EGFR phosphorylation and ubiquitination of EGFR in PANC-1 cells. YM155 also modestly promoted the ubiquitination of survivin and XIAP. Therefore, YM155 acts through modulation of EGFR and survivin expression to subsequently reduce survival. We suggest that YM155 has potential as a therapeutic agent in the treatment of pancreatic cancer