Alpha Particle Emission from6He + 209Bi

In a recent experiment, we have for the first time studied near-barrier and sub-barrier fusion of the exotic Borromean nucleus 6He with 209Bi and found that the sub-barrier fusion of this system is exceptionally enhanced, implying a 20% reduction in the nominal fusion barrier. It was suggested that this striking effect might he due to coupling to positive Q-value neutron transfer channels, leading to neutron flow and consequent neck formation between the projectile and target. The results of a new experiment using the radioactive nuclear beam facility at the University of Notre Dame to measure fast ⍺-particle emission from 6He + 209Bi are discussed. A exceptional1y strong transfer/breakup group was observed at near-barrier and sub-barrier energies; this is very likely to be the doorway state that explains the enhanced sub-barrier fusion. In a recent experiment, we have for the first time studied near-barrier and sub-barrier fusion of the exotic Borromean nucleus 6He with 209Bi and found that the sub-barrier fusion of this system is exceptionally enhanced, implying a 20% reduction in the nominal fusion barrier. It was suggested that this striking effect might he due to coupling to positive Q-value neutron transfer channels, leading to neutron flow and consequent neck formation between the projectile and target. The results of a new experiment using the radioactive nuclear beam facility at the University of Notre Dame to measure fast ⍺-particle emission from 6He + 209Bi are discussed. A exceptional1y strong transfer/breakup group was observed at near-barrier and sub-barrier energies; this is very likely to be the doorway state that explains the enhanced sub-barrier fusion

⁶³Ni(n,γ) cross sections measured with DANCE

The neutron capture cross section of the s-process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4πBaF2 array DANCE. The (n,γ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s-process sensitivity of the new values was analyzed with the new network calculation tool NETZ

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Recommendations for effective documentation in regional anesthesia: an expert panel Delphi consensus project

Background and objectives: Documentation is important for quality improvement, education, and research. There is currently a lack of recommendations regarding key aspects of documentation in regional anesthesia. The aim of this study was to establish recommendations for documentation in regional anesthesia. Methods: Following the formation of the executive committee and a directed literature review, a long list of potential documentation components was created. A modified Delphi process was then employed to achieve consensus amongst a group of international experts in regional anesthesia. This consisted of 2 rounds of anonymous electronic voting and a final virtual round table discussion with live polling on items not yet excluded or accepted from previous rounds. Progression or exclusion of potential components through the rounds was based on the achievement of strong consensus. Strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. Results: Seventy-seven collaborators participated in both rounds 1 and 2, while 50 collaborators took part in round 3. In total, experts voted on 83 items and achieved a strong consensus on 51 items, weak consensus on 3 and rejected 29. Conclusion: By means of a modified Delphi process, we have established expert consensus on documentation in regional anesthesia

Sleep phenotype in the Townes mouse model of sickle cell disease.

PURPOSE: Patients with sickle cell disease (SCD) regularly experience abnormal sleep, characterized by frequent arousals and reduced total sleep time. However, obstructive sleep apnea syndrome (OSAS) is a common comorbidity of SCD, making it unclear whether the disease per se is impacting sleep, or sleep disruption is secondary to the presence of OSAS. Thus, we assessed sleep, independent of OSAS, using a mouse model of SCD. METHODS: Sleep was compared between 10-to-12-week-old Townes knockout-transgenic mice with the sickle cell phenotype SS (n = 6) and Townes mice with sickle cell trait AS (n = 6; control). The mice underwent chronic polysomnographic electrode implantation (4EEG/2EMG) to assess sleep architecture. RESULTS: The SS mice had significantly lower hemoglobin concentration compared to control AS mice (7.3 ± 1.3 vs. 12.9 ± 1.7 g/dL; p \u3c 0.01), consistent with the expected SCD phenotype. SS mice exhibited significantly decreased total NREM sleep time (45.0 ± 0.7 vs. 53.0 ± 1.3% 24 h sleep time; p \u3c 0.01), but no change in total REM sleep time compared to the AS mice. The SS mice took longer to resume sleep after a wake period compared to the AS mice (3.2 ± 0.3 min vs. 1.9 ± 0.2 min; p \u3c 0.05). Unexpectedly, SS mice experienced fewer arousals compared to AS mice (19.0 ± 0.9 vs. 23.3 ± 2.1 arousals/h of sleep; p = 0.031). CONCLUSIONS: The presence of decreased total NREM sleep associated with reduced arousals, in the absence of OSAS, suggests a distinctive underlying sleep phenotype in a mouse model of SCD

The Emerging Role of Telemedicine in Diagnosing and Treating Sleep Disorders

Over one-third of adults are at risk of developing sleep disorders. Telemedicine is emerging as an effective tool in sleep medicine by allowing people to undergo sleep studies without overnight hospital stays (e.g. monitoring at home). Telemedicine has the potential to overcome several obstacles in the diagnosis and treatment of sleep disorders by offering increased access to sleep specialists, enhancing health-care support for patients in their homes and providing cost-effective professional education. The initial costs for telemedicine equipment and training are not insignificant; however, the benefits may outweigh the expense over time. However, recapturing the initial costs cannot be assumed

Infrarenal aortic occlusion: a reassessment of surgical indications.

Citing a high incidence of proximal propagation of aortic thrombosis, several authors have advocated aortic reconstruction for all patients with infrarenal aortic occlusion irrespective of their preoperative symptoms and potential operative risks. To test this thesis, the records and follow-up data of 38 patients seen at our institution between 1965 and 1982 with infrarenal aortic occlusion were analyzed. Twenty-four of the 38 patients were treated surgically (Group I); 16 (42 percent) had an aortobifemoral graft and 8 (21 percent) had an axillofemoral bypass graft. When the 14 patients who did not have surgery (Group II) and the 8 patients who had an axillofemoral graft were combined, 22 patients (58 percent) did not have aortic reconstruction (Group III), thus the aortic thrombus was left in situ. There was no significant difference in cumulative survival between the three groups at 4 year follow-up. Of 13 patients in Group III who were followed for more than 6 months (mean 48 months), none died from proximal propagation of aortic thrombosis. The decision for surgical intervention in patients with distal aortic occlusion should be arrived at, as in other patients with aortoiliac occlusive disease, by weighing preoperative symptoms and operative risks and not primarily by the level of risk of proximal propagation of thrombosis

Correlation of operative findings with angiographic and noninvasive hemodynamic factors associated with failure of polytetrafluoroethylene grafts.

The causes of autogenous saphenous vein (ASV) graft failure have been well described and are predominantly due to stenosis of the ASV graft during the first year after implantation. Distal atherosclerotic disease is a late cause of ASV graft failure. Furthermore, with failure of the ASV graft the clinical and hemodynamic status of the limb usually reverts to the preoperative state. To better define the causes and hemodynamic consequences of polytetrafluoroethylene (PTFE) graft failure, we reviewed the pathologic findings at surgery and compared these with arteriograms made prior to and after occlusion and sequential noninvasive hemodynamic studies in 36 patients with failed PTFE grafts (greater than 30 days after operation). Distal atherosclerotic disease was the most frequent cause of PTFE failure (23 of 36 limbs, or 64%), and it appeared as early as the first 6 months after implantation. Doppler pressures after PTFE failure deteriorated significantly (p less than 0.05) at the thigh, calf, and ankle levels. A blinded comparison of preoperative with postoperative arteriograms revealed significant progression of disease. Because of significant involvement of the popliteal artery in our series, treatment of intimal hyperplasia with patch angioplasty (seven cases, or 19%) was short lived and sequential extension was required. Distal atherosclerotic disease therefore appeared to be the most common cause of PTFE graft failure and occurred much earlier after implantation than with ASV graft failure. Deterioration of the hemodynamic state of the limb correlated with this high degree of distal atherosclerotic disease

A baboon flow-regulated shunt for the study of small caliber vascular grafts.

Synthetic vascular grafts often occlude when used in low-flow high-resistance reconstructions. In order to study the pathophysiology of graft failure a flow-regulated ex vivo shunt was designed for insertion into the baboon femoral artery and vein. Synthetic graft materials (4 mm i.d.) can be placed into the shunt circuit and studied at known rates of flow for uptake of 111In-labeled platelets. Segments of the grafts can be removed from the shunt circuit at specified time intervals for morphologic study with scanning electron microscopy (SEM). In this paper the shunt model is described in detail and early experiments with it are reported. Labeled platelet uptake and SEM studies suggest that flow rate and graft composition influence the deposition of platelets and other blood components on graft surfaces. At high-flow knitted Dacron attracts large numbers of platelets, and becomes covered with a nearly confluent platelet-protein carpet within 1 hr. At low flow platelet uptake and development of the platelet-protein carpet is slower. Polytetrafluoroethylene (PTFE) attracts few platelets at high-flow rates, but at lower-flow rates begins to develop a platelet-protein carpet similar to that seen on knitted Dacron. Flow-related factors influencing platelet deposition are discussed and further experiments to be carried out with this model are described

Results of elective abdominal aortic aneurysm repair in the 1990s: A population-based analysis of 2335 cases

Objective: The safety and efficacy of conventional abdominal aortic aneurysm (AAA) repair are undergoing increased examination in parallel with the development of less invasive repair methods. Because most published studies of elective AAA repair report operations performed in tertiary referral institutions and thus may not reflect the outcome in the surgical community at large, the current population-based study was undertaken to document the results obtained across a broad spectrum of clinical practice in a defined geographic area and to examine the factors that influence the outcomes. Methods: The Maryland Health Services Cost Review Commission database was used to identify all the elective AAA repairs that were performed in all the nonfederal acute care hospitals in the state from 1990 to 1995. Results: Elective AAA repair was performed on 2335 patients (mean age, 70.4 years) in 46 of the 52 (88%) nonfederal acute care hospitals in the state, including seven high-volume (\u3e100 cases), nine moderate-volume (50 to 99 cases), and 30 low-volume (\u3c50 cases) institutions. The in-hospital mortality rate was 3.5% and increased significantly with advancing age: less than 65 years, 2.2%; 65 to 69 years, 2.5%; 70 to 79 years, 3.5%; and more than 80 years, 7.3% (P = .002). Mortality rates were higher for women (4.5% vs 3.2%; P = .17), for blacks (6.7% vs 3.2%; P = .046), and for patients with renal failure (11.8% vs 3.4%; P = .11) but not for patients with hypertension, diabetes, heart disease, and pulmonary disease. The operative mortality rate was inversely correlated with hospital volume (4.3% in low- volume hospitals, 4.2% in moderate-volume hospitals, and 2.5% in high-volume hospitals; P = .08), although no differences were noted in the mean ages or comorbidity levels of patients who underwent operations in these three hospital populations. The operative mortality rate was inversely correlated with the experience of the individual surgeon: one case, 9.9%; two to nine cases, 4.9%; 10 to 49 cases, 2.8%; 50 to 99 cases, 2.9%; and more than 100 cases, 3.8% (P = .01). Multivariate analysis results identified patient age (P = .002), low hospital volume (P = .039), and very low surgeon volume (P = .01) as independent predictors of operative mortality. The mean length of stay and mean hospital charges were 10.6 days and $17,589 and decreased with increasing surgeon volume: one case, 22.7 days/$32,800; two to nine cases, 10.6 days/$18,509; 10 to 49 cases, 10.0 days/$16,611; 50 to 99 cases, 10.9 days/$17,843; and more than 100 cases, 9.6 days/$16,682 (P \u3c .0001/P \u3c .0001). Conclusion: Elective AAA repair is a safe procedure in contemporary practice in Maryland. Operative risk is increased among the elderly and when operations are performed by surgeons with very low volumes or in low-volume hospitals. Hospital lengths of stay were shorter and charges were lower when elective AAA repair was performed by surgeons with higher volumes