Monodisperse and isolated microspheres of poly(N-methylaniline) prepared by dispersion polymerization

Monodisperse and isolated microspheres of poly(N-methylaniline) were successfully prepared through chemical polymerization of N-methylaniline by S2O8 2- in adipic acid containing poly(vinylpyrrolidone) (PVP). Mean diameters of the microspheres with smooth surfaces changed from 320 to 100 nm by increasing the reaction temperature from 25 to 75oC. The concentration of PVP did not affect much the size of microspheres, but the increased PVP concentration led to longer induction times for the onset of dispersion polymerization

Electrical Characteristics of Pentacene Films on Cross-Linked Polymeric Insulators of Varying Thicknesses

Pentacene films vacuum-sublimed on a cross-linked polymeric insulator (CPVP–C₆) prepared using poly­(4-vinylphenol) (PVP) and 1,6-bis­(trichlorosilyl)­hexane (C₆) were studied with a special concern on possible influences of the CPVP–C₆ thickness on the electrical characteristics of the pentacene films. It was found that the conductivities of the pentacene films on a thin CPVP–C₆ film (10 nm) were approximately 2 orders of magnitude higher than those on a glass substrate and increased slightly with the increase in the thickness of the underlying CPVP–C₆ film. In addition, the X-ray diffraction measurements showed that the stacking structure of pentacene molecules was remarkably enhanced by increasing the thickness of the CPVP–C₆ film, suggesting that the increase in conductivity is due, at least in part, to the improvement in carrier mobilities caused by the growth of large pentacene grains. An attempt to directly evaluate carrier mobilities using pentacene/CPVP–C₆ field-effect transistors was made, and a seeming increase in the carrier mobilities observed with the increase in the CPVP–C₆ thickness was ascribed to a hygroscopic nature of the CPVP–C₆ film, which was evidenced by the capacitance and quartz crystal microbalance measurements. Possible reasons are discussed to explain the enhanced conductivities of the pentacene films on the increased thicknesses of CPVP–C₆

Single-incision laparoscopic gastropexy for mesentero-axial gastric volvulus

Abstract Background Mesentero-axial gastric volvulus (MAGV) is a rare but critical condition as delay in treatment can lead to lethal situations. Although the report of the surgical treatment with laparoscopic approach for MAGV has recently come to be seen, no standard procedures have been established. We aim to describe our operative technique of single-incision laparoscopic gastropexy (SILG) for MAGV and review the relevant literature to ascertain the most appropriate treatment option in these patients. Case presentation Three patients were referred to our hospital because abdominal pain and vomiting suddenly occurred. Acute MAGV was diagnosed by upper gastrointestinal study. After overnight gastric decompression with a nasal tube, the GV was resolved spontaneously. Elective SILG was planned. Single incision at the umbilicus was made and three 5-mm trocars were inserted. The anterior wall of the body of the stomach was sutured to the peritoneum using 6 × 4-0 non-absorbable sutures for prevention of recurrence of GV and occurrence of internal hernia through the space created between the sutures. Two boys and a girl with mean age 4 ± 2 years underwent SILG. The mean time of the operation was 48 ± 23 min. All of the procedures were completed safely, and there were no postoperative complications. The mean time of postoperative hospitalization was 4 ± 1 days. All patients had good cosmetic and clinical results. Conclusion We found SILG is a safe, technically feasible, and minimally invasive approach with low incidence of postoperative complication and the best cosmetic result for the patients with MAGV

National trends in the outcomes of subarachnoid haemorrhage and the prognostic influence of stroke centre capability in Japan: retrospective cohort study

Objectives To examine the national, 6-year trends in in-hospital clinical outcomes of patients with subarachnoid haemorrhage (SAH) who underwent clipping or coiling and the prognostic influence of temporal trends in the Comprehensive Stroke Center (CSC) capabilities on patient outcomes in Japan.Design Retrospective study.Setting Six hundred and thirty-one primary care institutions in Japan.Participants Forty-five thousand and eleven patients with SAH who were urgently hospitalised, identified using the J-ASPECT Diagnosis Procedure Combination database.Primary and secondary outcome measures Annual number of patients with SAH who remained untreated, or who received clipping or coiling, in-hospital mortality and poor functional outcomes (modified Rankin Scale: 3–6) at discharge. Each CSC was assessed using a validated scoring system (CSC score: 1–25 points).Results In the overall cohort, in-hospital mortality decreased (year for trend, OR (95% CI): 0.97 (0.96 to 0.99)), while the proportion of poor functional outcomes remained unchanged (1.00 (0.98 to 1.02)). The proportion of patients who underwent clipping gradually decreased from 46.6% to 38.5%, while that of those who received coiling and those left untreated gradually increased from 16.9% to 22.6% and 35.4% to 38%, respectively. In-hospital mortality of coiled (0.94 (0.89 to 0.98)) and untreated (0.93 (0.90 to 0.96)) patients decreased, whereas that of clipped patients remained stable. CSC score improvement was associated with increased use of coiling (per 1-point increase, 1.14 (1.08 to 1.20)) but not with short-term patient outcomes regardless of treatment modality.Conclusions The 6-year trends indicated lower in-hospital mortality for patients with SAH (attributable to better outcomes), increased use of coiling and multidisciplinary care for untreated patients. Further increasing CSC capabilities may improve overall outcomes, mainly by increasing the use of coiling. Additional studies are necessary to determine the effect of confounders such as aneurysm complexity on outcomes of clipped patients in the modern endovascular era

Rivaroxaban or aspirin for patent foramen ovale and embolic stroke of undetermined source: a prespecified subgroup analysis from the NAVIGATE ESUS trial

Background: Patent foramen ovale (PFO) is a contributor to embolic stroke of undetermined source (ESUS). Subgroup analyses from previous studies suggest that anticoagulation could reduce recurrent stroke compared with antiplatelet therapy. We hypothesised that anticoagulant treatment with rivaroxaban, an oral factor Xa inhibitor, would reduce the risk of recurrent ischaemic stroke compared with aspirin among patients with PFO enrolled in the NAVIGATE ESUS trial. Methods: NAVIGATE ESUS was a double-blinded, randomised, phase 3 trial done at 459 centres in 31 countries that assessed the efficacy and safety of rivaroxaban versus aspirin for secondary stroke prevention in patients with ESUS. For this prespecified subgroup analysis, cohorts with and without PFO were defined on the basis of transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE). The primary efficacy outcome was time to recurrent ischaemic stroke between treatment groups. The primary safety outcome was major bleeding, according to the criteria of the International Society of Thrombosis and Haemostasis. The primary analyses were based on the intention-to-treat population. Additionally, we did a systematic review and random-effects meta-analysis of studies in which patients with cryptogenic stroke and PFO were randomly assigned to receive anticoagulant or antiplatelet therapy. Findings: Between Dec 23, 2014, and Sept 20, 2017, 7213 participants were enrolled and assigned to receive rivaroxaban (n=3609) or aspirin (n=3604). Patients were followed up for a mean of 11 months because of early trial termination. PFO was reported as present in 534 (7·4%) patients on the basis of either TTE or TOE. Patients with PFO assigned to receive aspirin had a recurrent ischaemic stroke rate of 4·8 events per 100 person-years compared with 2·6 events per 100 person-years in those treated with rivaroxaban. Among patients with known PFO, there was insufficient evidence to support a difference in risk of recurrent ischaemic stroke between rivaroxaban and aspirin (hazard ratio [HR] 0·54; 95% CI 0·22–1·36), and the risk was similar for those without known PFO (1·06; 0·84–1·33; pinteraction=0·18). The risks of major bleeding with rivaroxaban versus aspirin were similar in patients with PFO detected (HR 2·05; 95% CI 0·51–8·18) and in those without PFO detected (HR 2·82; 95% CI 1·69–4·70; pinteraction=0·68). The random-effects meta-analysis combined data from NAVIGATE ESUS with data from two previous trials (PICSS and CLOSE) and yielded a summary odds ratio of 0·48 (95% CI 0·24–0·96; p=0·04) for ischaemic stroke in favour of anticoagulation, without evidence of heterogeneity. Interpretation: Among patients with ESUS who have PFO, anticoagulation might reduce the risk of recurrent stroke by about half, although substantial imprecision remains. Dedicated trials of anticoagulation versus antiplatelet therapy or PFO closure, or both, are warranted. Funding: Bayer and Janssen