Roughening and preroughening in the six vertex model with an extended range of interaction

We study the phase diagram of the BCSOS model with an extended interaction range using transfer matrix techniques, pertaining to the (100) surface of single component fcc and bcc crystals. The model shows a 2x2 reconstructed phase and a disordered flat phase. The deconstruction transition between these phases merges with a Kosterlitz-Thouless line, showing an interplay of Ising and Gaussian degrees of freedom. As in studies of the fully frustrated XY model, exponents deviating from Ising are found. We conjecture that tri-critical Ising behavior may be a possible explanation for the non-Ising exponents found in those models.Comment: 25 pages in RevTeX 3.0, seven uuencoded postscript figures, REPLACED because of submission error (figures were not included

Is surface melting a surface phase transition?

Monte Carlo or Molecular Dynamics calculations of surfaces of Lennard-Jones systems often indicate, apart from a gradual disordering of the surface called surface melting, the presence of a phase transition at the surface, but cannot determine the nature of the transition. In the present paper, we provide for a link between the continuous Lennard-Jones system and a lattice model. We apply the method for the (001) surface of a Lennard-Jones fcc structure pertaining to Argon. The corresponding lattice model is a Body Centered Solid on Solid model with an extended range of interaction, showing in principle rough, flat and disordered flat phases. We observe that entropy effects considerably lower the strength of the effective couplings between the atoms. The Argon (001) face is shown to exhibit a phase transition at T=70.5 +- 0.5 K, and we identify this transition as roughening. The roughening temperature is in good correspondence with experimental results for Argon.Comment: 17 pages REVTeX, 14 uuencoded postscript figures appende

Endoscopic full-thickness resection of T1 colorectal cancers:a retrospective analysis from a multicenter Dutch eFTR registry

Background Complete endoscopic resection and accurate histological evaluation for T1 colorectal cancer (CRC) are critical in determining subsequent treatment. Endoscopic full-thickness resection (eFTR) is a new treatment option for T1 CRC<2cm. We aimed to report clinical outcomes and short-term results. Methods Consecutive eFTR procedures for T1 CRC, prospectively recorded in our national registry between November 2015 and April 2020, were retrospectively analyzed. Primary outcomes were technical success and R0 resection. Secondary outcomes were histological risk assessment, curative resection, adverse events, and short-term outcomes. Results We included 330 procedures: 132 primary resections and 198 secondary scar resections after incomplete T1 CRC resection. Overall technical success, R0 resection, and curative resection rates were 87.0% (95% confidence interval [CI] 82.7%-90.3%), 85.6% (95%CI 81.2%-89.2%), and 60.3% (95%CI 54.7%-65.7%). Curative resection rate was 23.7% (95%CI 15.9%-33.6%) for primary resection of T1 CRC and 60.8% (95%CI 50.4%-70.4%) after excluding deep submucosal invasion as a risk factor. Risk stratification was possible in 99.3%. The severe adverse event rate was 2.2%. Additional oncological surgery was performed in 49/320 (15.3%), with residual cancer in 11/49 (22.4%). Endoscopic follow-up was available in 200/242 (82.6%), with a median of 4 months and residual cancer in 1 (0.5%) following an incomplete resection. Conclusions eFTR is relatively safe and effective for resection of small T1 CRC, both as primary and secondary treatment. eFTR can expand endoscopic treatment options for T1 CRC and could help to reduce surgical overtreatment. Future studies should focus on long-term outcomes

Patient-reported burden of intensified surveillance and surgery in high-risk individuals under pancreatic cancer surveillance

In high-risk individuals participating in a pancreatic cancer surveillance program, worrisome features warrant for intensified surveillance or, occasionally, surgery. Our objectives were to determine the patient-reported burden of intensified surveillance and/or surgery, and to assess post-operative quality of life and opinion of surgery. Participants in our pancreatic cancer surveillance program completed questionnaires including the Cancer Worry Scale (CWS) and the Hospital Anxiety and Depression Scale (HADS). For individuals who underwent intensified surveillance, questionnaires before, during, and ≥ 3 weeks after were analyzed. In addition, subjects who underwent intensified surveillance in the past 3 years or underwent surgery at any time, were invited for an interview, that included the Short-Form 12 (SF-12). A total of 31 high-risk individuals were studied. During the intensified surveillance period, median CWS scores were higher (14, IQR 7), as compared to before (12, IQR 9, P = 0.007) and after (11, IQR 7, P = 0.014), but eventually returned back to baseline (P = 0.823). Median HADS scores were low: 5 (IQR 6) for anxiety and 3 (IQR 5) for depression, and they were unaff

Influence of solid-state microstructure on the electronic performance of 5,11-Bis(triethylsilylethynyl) anthradithiophene

The rich phase behavior of 5,11-bis(triethylsilylethynyl) anthradithiophene (TES ADT) - one of the most promising, solution-processable small-molecular organic semiconductors - is analyzed, revealing the highest performing polymorph among four solid-state phases, opening pathways toward the reliable fabrication of high-performance bottom-gate/bottom-contact transistors.We are very grateful to the UK’s Engineering and Physical Sciences Research Council, the Dutch Polymer Institute (LATFE programme), and the ACS Petroleum Fund (New Directions Proposal) for financial support. We in addition acknowledge the EC’s seventh Framework Program ONE-P project (Grant Agreement 212311) for funding. N.S. is in addition supported by a European Research Council (ERC) Starting Independent Researcher Fellowship, under the grant agreement No. 279587. G.B. and E.P. acknowledges support from the ESF Project GOSPEL (Ref Nr: 09-EuroGRAPHENE-FP-001. G.B. acknowledges support from the Slovenian Research Agency, program P1-0055. N.W.O. is acknowledged for granting the beamtime at BM26B. J.E.A. acknowledges the Office of Naval Research for their support of the synthesis of organic semiconductor materials. G.B. and E.P. acknowledges support from the ESF Project GOSPEL (Ref Nr: 09-EuroGRAPHENE-FP-001). G.B. acknowledges support from the Slovenian Research Agency, program P1-0055

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Clip placement to prevent delayed bleeding after colonic endoscopic mucosal resection (CLIPPER): study protocol for a randomized controlled trial

Background: Endoscopic mucosal resection (EMR) for large colorectal polyps is in most cases the preferred treatment to prevent progression to colorectal carcinoma. The most common complication after EMR is delayed bleeding, occurring in 7% overall and in approximately 10% of polyps ≥ 2 cm in the proximal colon. Previous research has suggested that prophylactic clipping of the mucosal defect after EMR may reduce the incidence of delayed bleeding in polyps with a high bleeding risk. Methods: The CLIPPER trial is a multicenter, parallel-group, single blinded, randomized controlled superiority study. A total of 356 patients undergoing EMR for large (≥ 2 cm) non-pedunculated polyps in the proximal colon will be included and randomized to the clip group or the control group. Prophylactic clipping will be performed in the intervention group to close the resection defect after the EMR with a distance of < 1 cm between the clips. Primary outcome is delayed bleeding within 30 days after EMR. Secondary outcomes are recurrent or residual polyps and clip artifacts during surveillance colonoscopy after 6 months, as well as cost-effectiveness of prophylactic clipping and severity of delayed bleeding. Discussion: The CLIPPER trial is a pragmatic study performed in the Netherlands and is powered to determine the real-time efficacy and cost-effectiveness of prophylactic clipping after EMR of proximal colon polyps ≥ 2 cm in the Netherlands. This study will also generate new data on the achievability of complete closure and the effects of clip placement on scar surveillance after EMR, in order to further promote the debate on the role of prophylactic clipping in everyday clinical practice. Trial registration: ClinicalTrials.gov NCT03309683. Registered on 13 October 2017. Start recruitment: 05 March 2018. Planned completion of recruitment: 31 August 2021