Space hierarchy theorem revised

AbstractWe show that, for an arbitrary function h(n) and each recursive function ℓ(n), that are separated by a nondeterministically fully space constructible g(n), such that h(n)∈Ω(g(n)) but ℓ(n)∉Ω(g(n)), there exists a unary language L in NSPACE(h(n)) that is not contained in NSPACE(ℓ(n)). The same holds for the deterministic case.The main contribution to the well-known Space Hierarchy Theorem is that (i) the language L separating the two space classes is unary (tally), (ii) the hierarchy is independent of whether h(n) or ℓ(n) are in Ω(logn) or in o(logn), (iii) the functions h(n) or ℓ(n) themselves need not be space constructible nor monotone increasing, (iv) the hierarchy is established both for strong and weak space complexity classes. This allows us to present unary languages in such complexity classes as, for example, NSPACE(loglogn·log∗n)⧹NSPACE(loglogn), using a plain diagonalization

Totally thoracoscopic ablation for atrial fibrillation:a systematic safety analysis

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Endosonography With or Without Confirmatory Mediastinoscopy for Resectable Lung Cancer:A Randomized Clinical Trial

PURPOSE:Resectable non-small-cell lung cancer (NSCLC) with a high probability of mediastinal nodal involvement requires mediastinal staging by endosonography and, in the absence of nodal metastases, confirmatory mediastinoscopy according to current guidelines. However, randomized data regarding immediate lung tumor resection after systematic endosonography versus additional confirmatory mediastinoscopy before resection are lacking.METHODS:Patients with (suspected) resectable NSCLC and an indication for mediastinal staging after negative systematic endosonography were randomly assigned to immediate lung tumor resection or confirmatory mediastinoscopy followed by tumor resection. The primary outcome in this noninferiority trial (noninferiority margin of 8% that previously showed to not compromise survival, Pnoninferior &lt;.0250) was the presence of unforeseen N2 disease after tumor resection with lymph node dissection. Secondary outcomes were 30-day major morbidity and mortality.RESULTS:Between July 17, 2017, and October 5, 2020, 360 patients were randomly assigned, 178 to immediate lung tumor resection (seven dropouts) and 182 to confirmatory mediastinoscopy first (seven dropouts before and six after mediastinoscopy). Mediastinoscopy detected metastases in 8.0% (14/175; 95% CI, 4.8 to 13.0) of patients. Unforeseen N2 rate after immediate resection (8.8%) was noninferior compared with mediastinoscopy first (7.7%) in both intention-to-treat (Δ, 1.03%; UL 95% CIΔ, 7.2%; Pnoninferior =.0144) and per-protocol analyses (Δ, 0.83%; UL 95% CIΔ, 7.3%; Pnoninferior =.0157). Major morbidity and 30-day mortality was 12.9% after immediate resection versus 15.4% after mediastinoscopy first (P =.4940).CONCLUSION:On the basis of our chosen noninferiority margin in the rate of unforeseen N2, confirmatory mediastinoscopy after negative systematic endosonography can be omitted in patients with resectable NSCLC and an indication for mediastinal staging.</p

Transcatheter and minimally invasive surgical left ventricular reconstruction for the treatment of ischaemic cardiomyopathy: preliminary results†

OBJECTIVES: Adverse remodelling of the left ventricle (LV) after myocardial infarction (MI) results in a pathological increase in LV volume and reduction in LV ejection fraction (EF). We describe the preliminary results of a novel, multicentre, combined transcatheter and minimally invasive technique to reconstruct the remodelled LV by plication and exclusion of the scar, and to reduce the excess volume, resulting in decreased wall stress and increased EF. METHODS: A novel hybrid transcatheter technique that relies on microanchoring technology (Revivent TC™ System, BioVentrix Inc., San Ramon, CA, USA) was used. The LV is reconstructed without the use of extracorporeal circulation by plication of the fibrous scar. This is achieved by implantation of a series of internal and external microanchors brought together over a PEEK (poly-ether-ether-ketone) tether to form a longitudinal line of apposition between the LV free wall and the anterior septum. Internal anchors are deployed by a transcatheter technique on the right side of the ventricular septum through the right internal jugular vein. Paired external anchors are advanced through a left-sided minithoracotomy and deployed on the LV epicardium. A specialized force gauge is used to bring these 'right ventricle (RV)-LV' anchors together under measured compression forces. LV-LV' anchor pairs through the LV apex beyond the distal tip of the RV complete the reconstruction. Patients who were considered eligible for the procedure presented with symptomatic heart failure (New York Heart Association class ≥II) and ischaemic cardiomyopathy (EF <40%) after anteroseptal MI. All patients had a dilated LV with either an a- or dys-kinetic scar in the anteroseptal wall and apex of ≥50% transmurality. RESULTS: Between October 2016 and April 2017, 9 patients (8 men, 1 woman; mean age 60 ± 8 years) were operated on in 2 Dutch centres. Procedural success was 100%. On average, 2.6 anchor pairs were used to reconstruct the LV. Comparing echocardiographic data preoperatively and directly postoperatively, LV ejection fraction increased from 28 ± 8% to 40 ± 10% (change +43%, P < 0.001) and LV volumes decreased LV end-systolic volume index 53 ± 8 ml/m2 to 30 ± 11 ml/m2 (change -43%, P < 0.001) and LVEDVI 75 ± 23 ml/m2 to 45 ± 6 ml/m2 (change -40%, P = 0.001). In 1 patient, an RV perforation occurred which necessitated conversion to full sternotomy. One patient underwent a postoperative revision because of RV restriction. After the removal of 1 'RV-LV' anchor pair, the patient recovered completely. Hospital mortality was 0%. The median duration of intensive care unit stay was 2 days [interquartile range (IQR) 1-46 days], and the median length of hospital stay was 9 days (IQR 3-57 days). CONCLUSIONS: Hybrid transcatheter LV reconstruction is a promising novel treatment option for patients with symptomatic heart failure and ischaemic cardiomyopathy after anteroseptal MI. The early results demonstrate that the procedure is safe and results in a significant improvement in EF and reduction in LV volumes in the early postoperative period

Outcomes of cardiac surgery after mediastinal radiation therapy: A single-center experience

Background: Mediastinal radiation therapy (MRT) is a widely used therapy for thoracic malignancies. This therapy has the potential to cause cardiovascular injuries, which may require surgery. The primary aim of this study is to identify the perioperative outcomes of cardiac surgery in patients with a history of MRT. Second, potential predictors of mortality and adverse events were identified. Methods: A retrospective study was conducted among 59 patients with prior MRT who underwent cardiac surgery between December 2009 and March 2015. Included surgeries consisted of procedures through median- and ministernotomy. Baseline, perioperative, and follow-up data were obtained and analyzed. Results: The majority of patients had a history of breast cancer (n = 43), followed by Hodgkin lymphoma (n = 10) and non-Hodgkin lymphoma (n = 3). Preoperative estimated mortality with the Euroscore II was 3.4%. Overall 30-day mortality was 6.8% (n = 4), with a total in-hospital mortality of 10.2% (n = 6). Postoperatively, nine rethoracotomies (15.3%) had to be performed. During a mean follow-up of 53 months, an additional 10 patients (16.9%) died, of which 60% (n = 6) as a result of cancer-related events. Cox proportional modeling showed no differences in mortality between primary malignancies (P >.05). Conclusion: This study shows that cardiac surgery after mediastinal radiotherapy is associated with increased short- and long-term mortality when compared to preoperative mortality risks predicted by the Euroscore II. Surgery-related events caused all short-term mortality cases, while malignancy-related events were the main cause of death during the follow-up. Mortality was higher in patients with a previous stroke and a lower estimated glomerular filtration rate

Pharmacokinetics of BNP7787 and its metabolite mesna in plasma and ascites: a case report.

PURPOSE: BNP7787 (2',2'-dithio-bis-ethane sulfonate sodium) is a novel protector against cisplatin-induced toxicities. The pharmacokinetics of BNP7787 and its metabolite mesna were investigated in plasma and ascites of a cancer patient. We also evaluated potential pharmacokinetic interactions between BNP7787 and cisplatin. METHODS: BNP7787 and mesna were measured as mesna in deproteinized plasma and ascites using high-performance liquid chromatography with an electrochemical detector provided with a wall-jet gold electrode. RESULTS: After the i.v. administration of 41 g/m(2) BNP7787, BNP7787 and mesna had a half-life of 1.5 and 3.4 h, respectively. The AUC( infinity ) of mesna was approximately 8% of the AUC( infinity ) of BNP7787. Coadministration of cisplatin did not appear to influence the plasma concentration-time curves of BNP7787 and mesna. In ascites, approximately 0.02% of the BNP7787 dose was present as mesna, whereas approximately 4% of the dose was present as BNP7787 at the time of the maximum concentration. CONCLUSIONS: It can be concluded that the presence of ascites did not have a major impact on the pharmacokinetics of BNP7787 and coadministration of cisplatin did not influence the pharmacokinetics of BNP7787 and mesna

Intravascular Lipiodol Presenting as an Atrial Mass

A 68-year-old woman, previously treated with embolization of the thoracic duct with Lipiodol (an ethiodized oil injection) and cyanoacrylate glue (a topical tissue adhesive), was admitted with an asymptomatic mass in the inferior vena cava (IVC) and right atrium. The mass was surgically removed, and pathologic analysis revealed a Lipiodol-containing thrombus. To our knowledge, this is the first clinicopathologic report of Lipiodol-induced thrombus presenting as an intracavitary mass. (C) 2017 by The Society of Thoracic Surgeon