3,496 research outputs found

    Surgical repair of descending thoracic and thoracoabdominal aortic aneurysm involving the distal arch: Open proximal anastomosis under deep hypothermia versus arch clamping technique

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    BackgroundSurgical repair of a descending thoracic and thoracoabdominal aortic aneurysm (DTA/TAAA) involving the distal arch is challenging and requires either deep hypothermic circulatory arrest (DHCA) or crossclamping of the distal arch. The aim of this study was to compare these 2 techniques in the treatment of DTA/TAAA involving the distal arch.MethodsFrom 1994 to 2012, 298 patients underwent open repair of DTA/TAAA through a left thoracotomy. One hundred seventy-four patients with distal arch involvement who were suitable for either DHCA (nĀ =Ā 81) or arch clamping (AC; nĀ =Ā 93), were analyzed. In-hospital outcomes were compared using propensity scores and inverse-probability-of-treatment weighting adjustment to reduce treatment selection bias.ResultsEarly mortality was 11.1% in the DHCA group and 8.6% in the AC group (PĀ =Ā .58). Major adverse outcomes included stroke in 16 patients (9.2%), low cardiac output syndrome in 15 (8.6%), paraplegia in 10 (5.7%), and multiorgan failure in 10 (5.7%). After adjustment, patients who underwent DHCA were at similar risk of death (odds ratio [OR], 1.14; PĀ =Ā .80) and permanent neurologic injury (OR, 0.95; PĀ =Ā .92) to those who underwent AC. Although prolonged ventilator support (>24 hours) was more frequent with DHCA than with AC (OR, 2.60; PĀ =Ā .003), DHCA showed a tendency to lower the risk of paraplegia (OR, 0.15; PĀ =Ā .057).ConclusionsCompared with AC, DHCA did not increase postoperative mortality and morbidity, except for prolonged ventilator support. However, DHCA may offer superior spinal cord protection to AC during repair of DTA/TAAA involving the distal arch

    Interpreting positive signs of the supraspinatus test in screening for torn rotator cuff.

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    The purpose of this study was to investigate the validity of the supraspinatus test as a screening test for detecting torn rotator cuff and to determine what its valuable positive signs were. Both the empty-can test and full-can test were performed on 200 shoulders diagnosed by magnetic resonance imaging (MRI)-and in some cases, surgical findings-to have full-thickness or partial-thickness torn rotator cuff s, or no tear in the rotator cuff . During the maneuver, the presence of pain or weakness or both pain and weakness were recorded as positive signs, and the distribution of these signs were analyzed according to the degree of tear. The predictive values were calculated in 2 ways by considering (1) only full-thickness tears as tears and (2) both full- and partial-thickness tears as tears. The 2 tests and the 2 ways of considering partial-thickness tears were compared. Pain and weakness were severity-dependent, and the empty-can test had a higher incidence of pain. The sensitivities of the 2 supraspinatus tests in all positive signs were higher when including partial-thickness tears in the tear group ; however, their specificities were higher when excluding partial-thickness tears. Both pain and weakness were interpretive for the supraspinatus test, and both tests were sensitive to full- and partial- thickness tears and specific for full-thickness tears

    Highly circularly polarized white light using a combination of white polymer light-emitting diode and wideband cholesteric liquid crystal reflector

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    We present a simple and intriguing device that generates highly circularly polarized white light. It comprises white polymer light-emitting diodes (WPLEDs) attached to a wideband cholesteric liquid crystal (CLC) reflector with a wide photonic bandgap (PBG) covering the visible range. The degree of circular polarization realized is very high over the visible range. The wide PBG was realized by introducing a gradient in pitch of the cholesteric helix by controlling the twisting power within the CLC medium. WPLEDs fabricated using a ternary (red, green, and blue) fluorescent polymer blend with the same moiety showed a low turn-on voltage, high brightness, high efficiency, and good color stability.open0

    The impact of sequential versus single anastomoses on flow characteristics and mid-term patency of saphenous vein grafts in coronary bypass grafting

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    ObjectiveTo assess the influence of bypass grafting technique on the flow characteristics and mid-term patency of saphenous vein coronary bypass grafts.MethodsIn the present study, 309 patients who underwent either sequential (group A, NĀ =Ā 84 grafts) or individual (group B, NĀ =Ā 244 grafts) saphenous vein coronary bypass grafting between February 2002 and September 2007 were investigated. Individual bypassing only was performed in 212 patients, and sequential bypassing only was performed in 78 patients. The remaining 19 patients received both. A total of 436 distal anastomoses were performed with 328 saphenous vein grafts. The intraoperative flow characteristics and the graft patency were assessed with the transit time flow meter and serial multi-detector computed tomography coronary angiograms, respectively.ResultsGroup A showed a higher mean flow compared with group B at 49.4Ā Ā± 27.4 mL/min versus 37.1Ā Ā± 20.1 mL/min, respectively (PĀ =Ā .001). The mean flow increased linearly as the number of anastomoses increased per graft (PĀ <Ā .001). Graft patency at 3 years was 93.3%Ā Ā± 3.4% in group A and 86.5%Ā Ā± 3.1% in group BĀ (PĀ =Ā .048). After adjustment for baseline characteristics, group A showed a tendency for superior mid-term patency than group B (hazard ratio 0.362; 95% confidence interval, 0.129ā€“1.017; PĀ =Ā .0538).ConclusionsSequential bypass grafts were associated with higher mean flows and superior mid-term patency compared with individual grafts. These findings suggest the more favorable results of sequential bypass grafting to be attributed to the enhanced flow hemodynamics

    Digital Workflow for Retrofitting a Surveyed Crown Using a Removable Partial Denture as an Antagonist

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    Digital workflow expedites the procedure of retrofitting a surveyed crown against an existing removable partial denture (RPD). This article describes a simple and straightforward technique of digital workflow where an existing RPD is scanned as an antagonist to design the rest seat, guide plane, and height of contour of a surveyed crown.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/2/jopr13187_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/1/jopr13187.pd

    Quantitative measurements of C-reactive protein using silicon nanowire arrays

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    A silicon nanowire-based sensor for biological application showed highly desirable electrical responses to either pH changes or receptor-ligand interactions such as protein disease markers, viruses, and DNA hybridization. Furthermore, because the silicon nanowire can display results in real-time, it may possess superior characteristics for biosensing than those demonstrated in previously studied methods. However, despite its promising potential and advantages, certain process-related limitations of the device, due to its size and material characteristics, need to be addressed. In this article, we suggest possible solutions. We fabricated silicon nanowire using a top-down and low cost micromachining method, and evaluate the sensing of molecules after transfer and surface modifications. Our newly designed method can be used to attach highly ordered nanowires to various substrates, to form a nanowire array device, which needs to follow a series of repetitive steps in conventional fabrication technology based on a vapor-liquid-solid (VLS) method. For evaluation, we demonstrated that our newly fabricated silicon nanowire arrays could detect pH changes as well as streptavidin-biotin binding events. As well as the initial proof-of-principle studies, C-reactive protein binding was measured: electrical signals were changed in a linear fashion with the concentration (1 fM to 1 nM) in PBS containing 1.37 mM of salts. Finally, to address the effects of Debye length, silicon nanowires coupled with antigen proteins underwent electrical signal changes as the salt concentration changed
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