275 research outputs found

    Hair Bundle Morphology on Surviving Hair Cells of the Chick Basilar Papilla Exposed to Intense Sound

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    Exposure to intense sound produces a well-defined patch lesion on the chick basilar papilla in which 30-35% of the short hair cells are lost. The present study compares various aspects of sensory hair bundle morphology on surviving hair cells in the patch lesion with hair bundles from matched locations on nonexposed control papilla immediately after removal from the exposure and 12-days post exposure. The height and thickness of the hairs, the total number of hairs in the bundle, the width of the bundle, and the area and perimeter of the apical surface of the hair cell were quantified from scanning electron microscope photomicrographs. An attempt was also made to determine if there was a consistent microstructure to the pattern of hair cell loss within the lesion area. Similar observations in 12-day recovered ears are also presented. The results indicated that stereocilia height increased and width decreased on surviving hair cells in the exposed ear. The width of the hair bundle, the hair cell surface area, and perimeter also decreased. However, the number of hairs per cell remained unchanged, and there was no evidence of any consistent organization to the hair cell loss within the patch across a number of specimens. These observations indicated that the hair bundles on short hair cells underwent changes as a consequence of intense sound exposure.The results after 12 days of recovery were complicated by developmental changes on the papilla and incomplete maturation of the newly regenerated hair cells. It remains to be seen whether these changes were the result of cell sampling in the sound-damaged ear or were due to true structural alterations within the sensory hairs themselves

    Characterizing the Load Deformation Behaviour of Steel Deck Diaphragms

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    Lateral loads flow through a building’s horizontal roof and floor diaphragms before being transferred to the vertical lateral force resisting system (e.g. braced frames, moment frames or shear walls). These diaphragms are therefore a critical structural component in the resistance of lateral loads. A review of the literature shows that a large number of experimental programs have been performed to obtain the in-plane load-deformation behavior of steel deck and concrete on steel deck diaphragms. The tested diaphragm behavior was found to be dependent on a set of factors including loading protocol, fastener type, fastener size and spacing, and more. There does not currently exist a single, unifying review of these diaphragm tests and their relevant results. A research program is being conducted to collect and consolidate the available literature about tested steel deck diaphragms and their results. A database has been created that includes over 450 tested specimens with more than 130 cyclic tests. In addition, an effort is made to characterize diaphragms’ load-deformation response as grouped by sidelap and support fastener type. The test programs and results collected into this database as well as the characterization of diaphragm behavior are discussed in this paper

    Fetal Heart Rate Decelerations in Women with Sleep-Disordered Breathing

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    Emerging literature has shown that women with sleep-disordered breathing (SDB) have increased risk for gestational hypertension/preeclampsia and gestational diabetes. Case reports suggest an association between maternal apnea and fetal heart rate deceleration but data are lacking on how maternal sleep impacts fetal health. Since decelerations may be associated with adverse outcomes, we sought to determine whether fetal heart rate decelerations were associated with SDB. A cohort study of third trimester pregnant women with a singleton fetus was conducted. Participants underwent a home sleep test with continuous portable electronic fetal monitoring. SDB was defined as a respiratory disturbance index (RDI)≥10 events/hour. The temporality between a respiratory event and fetal heart rate decelerations was determined to be present if a deceleration occurred \u3c 30 s after a respiratory event. Forty women were included with mean (±SD) age, BMI, and gestational age of 32.0±5.5 years, 37.1±8.0 kg/m(2), and 34.6±2.4 weeks respectively. Overall, n=23 (57.5%) women had SDB. Thirty-seven late decelerations were observed in 18 women; of these, 84% were temporally associated with a respiratory event. Nine of the 18 women (50%) had SDB. Ten prolonged decelerations were observed in 6 women of which nine (90%) were temporally associated with a respiratory event. Five of the six women (83%) had an RDI≥10. These initial data suggest that, in this population, the majority of both late and prolonged fetal heart rate decelerations occur with a maternal respiratory event. Since respiratory events are characteristic of maternal SDB, this raises the possibility that SDB may influence fetal well-being

    Arthroscopic subscapularis bankart technique as a salvage procedure for failed anterior shoulder stabilization

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    BACKGROUND: Shoulder instability is a relatively common problem. Even with contemporary surgical techniques, instability can recur following both open and arthroscopic fixation. Surgical management of capsular insufficiency in anterior shoulder stabilization represents a significant challenge, particularly in young, active patients. There are a limited number of surgical treatment options. The Laterjet technique can present with a number of intraoperative challenges and postoperative complication.; DESCRIPTION OF TECHNIQUE: We report an arthroscopic subscapularis tenodesis technique as a salvage procedure for challenging glenohumeral instability cases. Sutures are passed through the subscapularis tendon and capsule before they are tied as one in the subdeltoid psace. The rotator interval is closed with superior and medial advancement of anterior and inferior tissue. This technical note carefully describes this procedure with useful technical tips, illustrations, and diagrams.; PATIENTS AND METHODS: Two clinical cases are described involving patients with recurrent instability following failed surgery who were successfully managed with this procedure.; RESULTS: Both cases described resulted in improved shoulder stability, range of motion, and function following management with this surgical technique. This arthroscopic subscapularis tenodesis procedure is proposed as a useful alternative repair technique for cases of recurrent instability after failed surgery with isolated capsular insufficiency.; CONCLUSION: It is believed that this arthroscopic subscapularis tenodesis technique can potentially provide similar outcomes to open bone block stabilization procedures, while reducing the risks associated with those procedures

    Affirmative Action Bans and Health Risk Behaviors

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    College affirmative action bans were associated with higher rates of smoking and drinking in underrepresented minority 11th and 12th graders, and these students continued to smoke at higher rates into young adulthood. Policymakers should consider unintended public health consequences of proposals, such as affirmative action bans, that may limit socioeconomic opportunities

    Dynamic compression can inhibit chondrogenesis of mesenchymal stem cells.

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    The objective of this study was to investigate the influence of dynamic compressive loading on chondrogenesis of mesenchymal stem cells (MSCs) in the presence of TGF-beta3. Isolated porcine MSCs were suspended in 2% agarose and subjected to intermittent dynamic compression (10% strain) for a period of 42 days in a dynamic compression bioreactor. After 42 days in culture, the free-swelling specimens exhibited more intense alcian blue staining for proteoglycans, while immunohistochemical analysis revealed increased collagen type II immunoreactivity. Glycosaminoglycan (GAG) content increased with time for both free-swelling and dynamically loaded constructs, and by day 42 it was significantly higher in both the core (2.5+/-0.21%w/w vs. 0.94+/-0.03%w/w) and annulus (1.09+/-0.09%w/w vs. 0.59+/-0.08%w/w) of free-swelling constructs compared to dynamically loaded constructs. This result suggests that further optimization is required in controlling the biomechanical and/or the biochemical environment if such stimuli are to have beneficial effects in generating functional cartilaginous tissue

    Ibrutinib versus Ofatumumab in Previously Treated Chronic Lymphoid Leukemia

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    Background In patients with chronic lymphoid leukemia (CLL) or small lymphocytic lymphoma (SLL), a short duration of response to therapy or adverse cytogenetic abnormalities are associated with a poor outcome. We evaluated the efficacy of ibrutinib, a covalent inhibitor of Bruton\u27s tyrosine kinase, in patients at risk for a poor outcome. Methods In this multicenter, open-label, phase 3 study, we randomly assigned 391 patients with relapsed or refractory CLL or SLL to receive daily ibrutinib or the anti-CD20 antibody ofatumumab. The primary end point was the duration of progression-free survival, with the duration of overall survival and the overall response rate as secondary end points. Results At a median follow-up of 9.4 months, ibrutinib significantly improved progression-free survival; the median duration was not reached in the ibrutinib group (with a rate of progression-free survival of 88% at 6 months), as compared with a median of 8.1 months in the ofatumumab group (hazard ratio for progression or death in the ibrutinib group, 0.22;

    Conduite du changement et management par la qualité pour une meilleure dynamique de recherche finalisée : Retour d’expérience dans un laboratoire de recherche en horticulture et production de semences

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    Cet article issu d'un regard pluridisciplinaire (ingénierie des systèmes, sciences physiques, biologie, psychologie du travail, sciences de gestion et ergonomie), porte sur la conduite du changement à travers un Système de management de la qualité (SMQ) au sein d'un laboratoire de recherche en biologie, avec comme focus principal les résistances et les leviers. L'autre angle choisi concerne l'intérêt d'un SMQ pour un laboratoire dans le but de fiabiliser les résultats de recherche, anticiper et maîtriser les risques liés aux activités de recherche et l'impact sur la cohésion et la motivation des personnes. Il est assorti d'exemples pratiques montrant les bénéfices et les améliorations induites

    Sudden onset headache in a post-partum young female

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     We present the case of a 33 year old female presenting with acute neurological signs including right sided neglect and confusion four days postpartum. The original non-contrast CT brain demonstrated an acute left temporal intraparenchymal hemorrhage. A cerebral catheter angiogram was performed and demonstrated the typical appearances of RCVS (Reversible cerebral vasoconstriction syndrome)
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