29 research outputs found

    The impact of the mixing properties within the Antarctic stratospheric vortex on ozone loss in spring

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    Calculations of equivalent length from an artificial advected tracer provide new insight into the isentropic transport processes occurring within the Antarctic stratospheric vortex. These calculations show two distinct regions of approximately equal area: a strongly mixed vortex core and a broad ring of weakly mixed air extending out to the vortex boundary. This broad ring of vortex air remains isolated from the core between late winter and midspring. Satellite measurements of stratospheric H2O confirm that the isolation lasts until at least mid-October. A three-dimensional chemical transport model simulation of the Antarctic ozone hole quantifies the ozone loss within this ring and demonstrates its isolation. In contrast to the vortex core, ozone loss in the weakly mixed broad ring is not complete. The reasons are twofold. First, warmer temperatures in the broad ring prevent continuous polar stratospheric cloud (PSC) formation and the associated chemical processing (i.e., the conversion of unreactive chlorine into reactive forms). Second, the isolation prevents ozone-rich air from the broad ring mixing with chemically processed air from the vortex core. If the stratosphere continues to cool, this will lead to increased PSC formation and more complete chemical processing in the broad ring. Despite the expected decline in halocarbons, sensitivity studies suggest that this mechanism will lead to enhanced ozone loss in the weakly mixed region, delaying the future recovery of the ozone hole

    Quantitative assessment of barriers to the clinical development and adoption of cellular therapies:A pilot study

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    There has been a large increase in basic science activity in cell therapy and a growing portfolio of cell therapy trials. However, the number of industry products available for widespread clinical use does not match this magnitude of activity. We hypothesize that the paucity of engagement with the clinical community is a key contributor to the lack of commercially successful cell therapy products. To investigate this, we launched a pilot study to survey clinicians from five specialities and to determine what they believe to be the most significant barriers to cellular therapy clinical development and adoption. Our study shows that the main concerns among this group are cost-effectiveness, efficacy, reimbursement, and regulation. Addressing these concerns can best be achieved by ensuring that future clinical trials are conducted to adequately answer the questions of both regulators and the broader clinical community

    A preliminary randomized double blind placebo-controlled trial of intravenous immunoglobulin for Japanese encephalitis in Nepal

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    BACKGROUND: Japanese encephalitis (JE) virus (JEV) is a mosquito-borne flavivirus found across Asia that is closely related to West Nile virus. There is no known antiviral treatment for any flavivirus. Results from in vitro studies and animal models suggest intravenous immunoglobulin (IVIG) containing virus-specific neutralizing antibody may be effective in improving outcome in viral encephalitis. IVIG's anti-inflammatory properties may also be beneficial. METHODOLOGY/PRINCIPAL FINDINGS: We performed a pilot feasibility randomized double-blind placebo-controlled trial of IVIG containing anti-JEV neutralizing antibody (ImmunoRel, 400mg/kg/day for 5 days) in children with suspected JE at two sites in Nepal; we also examined the effect on serum neutralizing antibody titre and cytokine profiles. 22 children were recruited, 13 of whom had confirmed JE; 11 received IVIG and 11 placebo, with no protocol violations. One child (IVIG group) died during treatment and two (placebo) subsequently following hospital discharge. Overall, there was no difference in outcome between treatment groups at discharge or follow up. Passive transfer of anti-JEV antibody was seen in JEV negative children. JEV positive children treated with IVIG had JEV-specific neutralizing antibody titres approximately 16 times higher than those treated with placebo (p=0.2), which was more than could be explained by passive transfer alone. IL-4 and IL-6 were higher in the IVIG group. CONCLUSIONS/SIGNIFICANCE: A trial of IVIG for JE in Nepal is feasible. IVIG may augment the development of neutralizing antibodies in JEV positive patients. IVIG appears an appealing option for JE treatment that warrants further study. TRIAL REGISTRATION: ClinicalTrials.gov NCT01856205

    The impact of the mixing properties within the Antarctic stratospheric vortex on ozone loss in spring

    No full text
    Calculations of equivalent length from an artificial advected tracer provide new insight into the isentropic transport processes occurring within the Antarctic stratospheric vortex. These calculations show two distinct regions of approximately equal area: a strongly mixed vortex core and a broad ring of weakly mixed air extending out to the vortex boundary. This broad ring of vortex air remains isolated from the core between late winter and midspring. Satellite measurements of stratospheric H2O confirm that the isolation lasts until at least mid-October. A three-dimensional chemical transport model simulation of the Antarctic ozone hole quantifies the ozone loss within this ring and demonstrates its isolation. In contrast to the vortex core, ozone loss in the weakly mixed broad ring is not complete. The reasons are twofold. First, warmer temperatures in the broad ring prevent continuous polar stratospheric cloud (PSC) formation and the associated chemical processing (i.e., the conversion of unreactive chlorine into reactive forms). Second, the isolation prevents ozone-rich air from the broad ring mixing with chemically processed air from the vortex core. If the stratosphere continues to cool, this will lead to increased PSC formation and more complete chemical processing in the broad ring. Despite the expected decline in halocarbons, sensitivity studies suggest that this mechanism will lead to enhanced ozone loss in the weakly mixed region, delaying the future recovery of the ozone hole

    Complex elbow Instability: treatment and rehabilitation

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    Complex elbow instability represent a challenging injury even for expert elbow surgeons. Chronic instability, posttraumatic osteo-arthritis, stiffness and poor functional outcomes are frequent if these injuries are not adequately treated. A correct preoperative evaluation includes X-rays, CT scan with 2D and 3D reconstruction and stability tests under fluoroscopy in order to recognize all osseous and ligamentous lesions. The most common patterns of complex elbow instability includes: (1) radial head fractures associated with lateral and medial collateral ligaments lesions; (2) coronoid fractures and lateral collateral ligament lesion; (3) Terrible Triad; (4) fracture-dislocations of the proximal ulna and radius, also referred to as transolecranon fracture-dislocations and Monteggia-like lesions; and (5) humeral shear fractures associated with lateral and medial collateral ligament lesions. The main goals of the treatment are (1) to perform a stable osteosynthesis of all fractures, (2) to obtain concentric and stable reduction of the elbow throught the repair of soft tissue constraint lesions and (3) to allow early motion. All the patterns of complex elbow instability share the same therapeutic algorithm based on seven main principles: 1) the proximal ulna must be anatomically reduced and fixed; 2) the radial head or humeral shear fracture must be repaired or replaced, 3) bone length, alignment and rotation of ulnar and radial shaft fractures must be recovered; 4) the lateral collateral ligament complex must be repaired to obtain elbow stability; 5) the medial collateral ligament must be repaired if persistent instability is observed after lateral collateral ligament repair; 6) an hinged external fixator must be considered if the elbow remains unstable or the protection of the joint reconstruction is required; 7) re-evaluation of the surgical steps if congruent ulno-humeral and radio-humeral joints have not been achieved. Following the surgical treatment an adequate rehabilitation programme should be started promptly and continued for at least 6 months since a significant improvement of the range of motion occurs prevalently in this period, which should be considered the critical time period to obtain a functional elbow
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