Theoretical study of the absorption spectra of the lithium dimer

For the lithium dimer we calculate cross sections for absorption of radiation from the vibrational-rotational levels of the ground X [singlet Sigma g +] electronic state to the vibrational levels and continua of the excited A [singlet Sigma u +] and B [singlet Pi u] electronic states. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from photoassociation spectroscopy and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 1000 to 2000 K and are compared with previous calculations and measurements.Comment: 20 pages, revtex, epsf, 6 fig

Theoretical study of the absorption spectra of the sodium dimer

Absorption of radiation from the sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X Sigma-g+ state to the first excited singlet A Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the first excited triplet b Sigma-g+ and triplet c Pi-g states are studied quantum-mechanically. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from ab initio calculations, spectroscopy, and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 500 to 3000 K and are compared with previous calculations and measurements where available.Comment: 19 pages, 8 figures, revtex, eps

Handlebar hernia: a case report and literature review on traumatic abdominal wall hernia in children

A rare case of abdominal trauma, a handlebar hernia, is described, as well as a review of the pertinent literature. A 7-year-old boy presented to our emergency room after sustaining blunt force to the abdomen; he fell on the handlebar of his bicycle. Immediately after the accident, a bulge was noticeable at the point of impact. Handlebar hernia is a diagnosis that is easily missed, which can lead to strangulation and incarceration of the bowel. With this case report, we hope to augment the knowledge on traumatic abdominal wall hernia, hopefully leading to early diagnosis and treatment

Midterm results of the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair

Objective The fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) was introduced in 2010 and showed promising short-term results with high technical success and low morbidity rates. The aim of this study was to present the midterm results, with a minimum of 12 months follow-up, for all patients treated with the fenestrated Anaconda endograft in The Netherlands. Methods Patients treated with the fenestrated Anaconda endograft between May 2011 and February 2015 were included. Follow-up consisted of computed tomography angiography at 1 month and 1 year, and duplex ultrasound yearly thereafter with additional computed tomography angiography if indicated using a standard protocol. Results A total of 60 patients were included; 48 patients (80.0%) were treated for juxtarenal aneurysms, and 12 (20.0%) were short-neck infrarenal aneurysms. Mean aneurysm size was 64 ± 9 mm. A total of 140 fenestrations were incorporated. Median follow-up was 16.4 months (interquartile range, 11.9-27.4). The 30-day mortality was 3.4% (n = 2). Kaplan-Meier estimates for 1-year, 2-year, and 3-year survival were 91.4%, 89.5%, and 86.3%, respectively, without aneurysm-related mortality during follow-up. Main body primary and secondary endograft patencies were 98.3% and 100%, respectively. Target vessel primary and secondary patencies were 95.0% and 98.6%, respectively. Early type IA endoleaks occurred in seven patients (11.7%) and spontaneously resolved in all patients. At 1-year follow-up 4 (6.7%) type II endoleaks persisted. One patient experienced aneurysm rupture because of a late type III endoleak attributable to a dislodged renal stent and subsequently underwent successful conversion to open surgery. Conclusions The fenestrated Anaconda is a viable treatment option for complex abdominal aortic aneurysms. Acceptable mortality and morbidity and low reintervention rates contribute to good midterm results. Occurrence of early type I endoleak was relatively common, but these resolved spontaneously in all patients

Association of Hospital Volume with Perioperative Mortality of Endovascular Repair of Complex Aortic Aneurysms: A Nationwide Cohort Study

Objective: We evaluate nationwide perioperative outcomes of complex EVAR and assess the volume-outcome association of complex EVAR. Summary of Background Data: Endovascular treatment with fenestrated (FEVAR) or branched (BEVAR) endografts is progressively used for excluding complex aortic aneurysms (complex AAs). It is unclear if a volumeoutcome association exists in endovascular treatment of complex AAs (complex EVAR). Methods: All patients prospectively registered in the Dutch Surgical Aneurysm Audit who underwent complex EVAR (FEVAR or BEVAR) between January 2016 and January 2020 were included. The effect of annual hospital volume on perioperative mortality was examined using multivariable logistic regression analyses. Patients were stratified into quartiles based on annual hospital volume to determine hospital volume categories. Results: We included 694 patients (539 FEVAR patients, 155 BEVAR patients). Perioperative mortality following FEVAR was 4.5% and 5.2% following BEVAR. Postoperative complication rates were 30.1% and 48.7%, respectively. The first quartile hospitals performed <9 procedures/ yr; second, third, and fourth quartile hospitals performed 9-12, 13-22, and 23 procedures/yr. The highest volume hospitals treated significantly more complex patients. Perioperative mortality of complex EVAR was 9.1% in hospitals with a volume of <9, and 2.5% in hospitals with a volume of 13 (P = 0.008). After adjustment for confounders, an annual volume of 13 was associated with less perioperative mortality compared to hospitals with a volume of <9. Conclusions: Data from this nationwide mandatory quality registry shows a significant effect of hospital volume on perioperative mortality following complex EVAR, with high volume complex EVAR centers demonstrating lower mortality rates