Challenges in the development of the orbiter atmosphere revitalization subsystem

The space shuttle orbiter atmospheric revitalization subsystem provides thermal and contaminant control as well as total- and oxygen partial-pressure control of the environment within the orbiter crew cabin. Challenges that occurred during the development of this subsystem for the space shuttle orbiter are described. The design of the rotating hardware elements of the system (pumps, fans, etc.) required significant development to meet the requirements of long service life, maintainability, and high cycle-fatigue life. As a result, a stringent development program, particularly in the areas of bearing life and heat dissipation, was required. Another area requiring significant development was cabin humidity control and condensate collection

Elective endovascular and open repair of abdominal aortic aneurysms in octogenarians

ObjectivesEndovascular aortic aneurysm repair (EVAR) is an increasingly popular treatment option for patients with abdominal aortic aneurysms (AAA), although open repair is considered the standard by virtue of its durability. Octogenarians, as a subgroup, may stand to benefit the most by EVAR. The purpose of this study is to review operative results and durability of open AAA repair and EVAR in octogenarians.MethodsFrom May 1996 to August 2006, 150 patients aged ≥80 years underwent elective repair of their infrarenal AAA. Eighty-one underwent EVAR and 69 had open repair. Demographic data, aneurysm specifics, comorbidities, operative morbidity and mortality, intensive care unit and hospital length of stay, and late outcomes were analyzed.ResultsIn the EVAR group, 27 of 81 (33%) patients died during a mean follow-up of 25 months. In the open repair group, 34 of 69 (49%) patients died during a mean follow-up of 43 months. The median survival time for EVAR was 350 weeks (range, 145-404 weeks) compared with 317 weeks (range, 233-342 weeks) for the open repair group. A Kaplan-Meier log-rank analysis showed no difference in early or long-term survival between EVAR and open repair (P = .13). EVAR was associated with decreased blood loss, decreased length of intensive care unit and hospital stays, and a greater number of patients discharged to home.ConclusionsEVAR and open repair are comparable in safety and efficacy in octogenarians. Operative repair outcomes remain acceptable. Mid- and long-term survival are similar, indicating no survival advantage of one procedure compared with the other

Predictors of depression relapse and recurrence after cognitive behavioural therapy: a systematic review and meta-analysis

Background: Cognitive behavioural therapy (CBT) is an effective psychological treatment for major depressive disorder, although some patients experience a return of symptoms after finishing therapy. The ability to predict which individuals are more vulnerable to deterioration would allow for targeted interventions to prevent short-term relapse and longer-term recurrence. Aim: This systematic review and meta-analysis aimed to identify factors associated with an increased risk of relapse and/or recurrence (RR) after CBT for depression. Method: We reviewed 13 relevant papers, of which a small set of unique samples were eligible for meta-analysis (k = 5, N = 369). Twenty-six predictor variables were identified and grouped into seven categories: residual depressive symptoms; prior episodes of depression; cognitive reactivity; stressful life events; personality factors; clinical and diagnostic factors; demographics. Results: Meta-analyses indicated that residual depressive symptoms (r = 0.34 [0.10, 0.54], p = .01) and prior episodes (r = 0.19 [0.07, 0.30], p = .002) were statistically significant predictors of RR, but cognitive reactivity was not (r = 0.18 [−0.02, 0.36], p = .08). Other variables lacked replicated findings. On average, 33.4% of patients experienced RR after CBT. Conclusions: Patients with the above risk factors could be offered evidence-based continuation-phase interventions to enhance the longer-term effectiveness of CBT

A randomized, controlled trial of endovenous thermal ablation using the 810-nm wavelength laser and the ClosurePLUS radiofrequency ablation methods for superficial venous insufficiency of the great saphenous vein

BackgroundGreat saphenous vein (GSV) incompetence is the most common cause of superficial venous insufficiency. Radiofrequency catheter ablation (RFA) is superior to conventional ligation and stripping, and endovenous laser treatment (EVL) has emerged as an effective alternative to RFA. This randomized study evaluated RFA and EVL for superficial venous insufficiency due to GSV incompetence and compared early and 1-year results.MethodsBetween June 2006 and May 2008, patients with symptomatic primary venous insufficiency due to GSV incompetence were randomized to RFA or EVL. Patients with bilateral disease were randomized for treatment of the first leg and received the alternative method on the other. Pretreatment examination included a leg assessment using the Venous Clinical Severity Score (VCSS) and CEAP classification. Patients completed the Chronic Venous Insufficiency Questionnaire 2 (CIVIQ2). RFA was performed with the ClosurePlus system (VNUS Medical Technologies, Sunnyvale, Calif). EVL was performed with the EVLT system (AngioDynamics Inc, Queensbury, NY). Early (1-week and 1-month) postoperative results of pain, bruising, erythema, and hematoma were recorded. Duplex ultrasound (DU) imaging was used at 1 week and 1 year to evaluate vein status. VCSS scores and CEAP clinical class were recorded at each postoperative visit, and quality of life (QOL) using CIVIQ2 was assessed at 1 month and 1 year.ResultsThe study enrolled 118 patients (141 limbs): 46 (39%) were randomized to RFA and 48 (40%) to EVL, and 24 (20%) had bilateral GSV incompetence. At 1 week, one patient in the RFA group had an open GSV and was deemed a failure. More bruising occurred in the EVL group (P = .01) at 1 week, but at 1 month, there was no difference in bruising between groups. At 1 year, DU imaging showed evidence of recanalization with reflux in 11 RFA and 2 EVL patients (P = .002). The mean VCSS score change from baseline to 1 week postprocedure was higher for RFA than EVL (P = .002), but there was no difference between groups at 1 month (P = .07) and 1 year (P = .9). Overall QOL mean score improved over time for all patients (P < .001). CEAP clinical class scores of ≥3 were recorded in 21 RFA (44%) and 24 EVL patients (44%) pretreatment, but at 1-year, 9 RFA (19%) and 12 EVL patients (24%) had scores of ≥3 (P < .001). This represented a significant improvement in all patients compared with baseline.ConclusionBoth methods of endovenous ablation effectively reduce symptoms of superficial venous insufficiency. EVL is associated with greater bruising and discomfort in the perioperative period but may provide a more secure closure over the long-term than RFA

Activated MCTC mast cells infiltrate diseased lung areas in cystic fibrosis and idiopathic pulmonary fibrosis

<p>Abstract</p> <p>Background</p> <p>Although mast cells are regarded as important regulators of inflammation and tissue remodelling, their role in cystic fibrosis (CF) and idiopathic pulmonary fibrosis (IPF) has remained less studied. This study investigates the densities and phenotypes of mast cell populations in multiple lung compartments from patients with CF, IPF and never smoking controls.</p> <p>Methods</p> <p>Small airways, pulmonary vessels, and lung parenchyma were subjected to detailed immunohistochemical analyses using lungs from patients with CF (20 lung regions; 5 patients), IPF (21 regions; 7 patients) and controls (16 regions; 8 subjects). In each compartment the densities and distribution of MC_Tand MC_TCmast cell populations were studied as well as the mast cell expression of IL-6 and TGF-β.</p> <p>Results</p> <p>In the alveolar parenchyma in lungs from patients with CF, MC_TCnumbers increased in areas showing cellular inflammation or fibrosis compared to controls. Apart from an altered balance between MC_TCand MC_Tcells, mast cell in CF lungs showed elevated expression of IL-6. In CF, a decrease in total mast cell numbers was observed in small airways and pulmonary vessels. In patients with IPF, a significantly elevated MC_TCdensity was present in fibrotic areas of the alveolar parenchyma with increased mast cell expression of TGF-β. The total mast cell density was unchanged in small airways and decreased in pulmonary vessels in IPF. Both the density, as well as the percentage, of MC_TCcorrelated positively with the degree of fibrosis. The increased density of MC_TC, as well as MC_TCexpression of TGF-β, correlated negatively with patient lung function.</p> <p>Conclusions</p> <p>The present study reveals that altered mast cell populations, with increased numbers of MC_TCin diseased alveolar parenchyma, represents a significant component of the histopathology in CF and IPF. The mast cell alterations correlated to the degree of tissue remodelling and to lung function parameters. Further investigations of mast cells in these diseases may open for new therapeutic strategies.</p

Cystic Fibrosis, Atopy, Asthma and ABPA

The role of atopy on cystic fibrosis (CF) progression remains unclear but evidence suggests that it may influence the appearance of co-morbid conditions such as CF asthma or allergic bronchopulmonary aspergillosis (ABPA). Recognising asthma in patients with CF is not always easy but the identification of atopic markers favours the diagnosis. Physicians should be aware of this fact in order to achieve a better control of respiratory symptoms in patients with CF. Bronchial mucosa inflammation and abnormal mucus predispose to mould colonisation. These patients are at higher risk of allergic sensitisation, especially when atopic susceptibility is present. In the particular case of A. fumigatus, allergic sensitisation precedes ABPA development, which occurs in up to 10% of CF patients. Progression of lung function deterioration is most strikingly pronounced in patients with ABPA. Therefore, sensitisation with A. fumigatus should be regularly tested in patients with CF, especially those at higher risk. Recombinant allergens constitute an important advance in differentiating Aspergillus sensitisation from ABPA itself

Impact of Aspergillus fumigatus in allergic airway diseases

For decades, fungi have been recognized as associated with asthma and other reactive airway diseases. In contrast to type I-mediated allergies caused by pollen, fungi cause a large number of allergic diseases such as allergic bronchopulmonary mycoses, rhinitis, allergic sinusitis and hypersensitivity pneumonitis. Amongst the fungi, Aspergillus fumigatus is the most prevalent cause of severe pulmonary allergic disease, including allergic bronchopulmonary aspergillosis (ABPA), known to be associated with chronic lung injury and deterioration in pulmonary function in people with chronic asthma and cystic fibrosis (CF). The goal of this review is to discuss new understandings of host-pathogen interactions in the genesis of allergic airway diseases caused by A. fumigatus. Host and pathogen related factors that participate in triggering the inflammatory cycle leading to pulmonary exacerbations in ABPA are discussed

Application of graphs in the analysis of vibrating 3-dimensional systems

Vibrating 3-dimensional mechanical systems are described by hybrid graphs. By dividing the hybrid graph into a tree and associated co-tree it is possible to describe in terms of matrices: across-flow-variables, stiffness and flexibility. The application of the formalism of graphs makes it possible to analyze mechanical systems in terms of dynamic characteristic and trajectory motion of determinate points

Application of Graphs in the Analysis of Vibrating 3-Dimensional Systems

Vibrating 3-dimensional mechanical systems are described by hybrid graphs. By dividing the hybrid graph into a tree and associated co-tree it is possible to describe in terms of matrices: across-flow-variables, stiffness and flexibility. The application of the formalism of graphs makes it possible to analyze mechanical systems in terms of dynamic characteristic and trajectory motion of determinate points