114 research outputs found

    Mechanism and Uses of a Membrane Peptide that Targets Tumors and Other Acidic Tissues \u3cem\u3eIn Vivo\u3c/em\u3e

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    The pH-selective insertion and folding of a membrane peptide, pHLIP [pH (low) insertion peptide], can be used to target acidic tissue in vivo, including acidic foci in tumors, kidneys, and inflammatory sites. In a mouse breast adenocarcinoma model, fluorescently labeled pHLIP finds solid acidic tumors with high accuracy and accumulates in them even at a very early stage of tumor development. The fluorescence signal is stable for \u3e4 days and is approximately five times higher in tumors than in healthy counterpart tissue. In a rat antigen-induced arthritis model, pHLIP preferentially accumulates in inflammatory foci. pHLIP also maps the renal cortical interstitium; however, kidney accumulation can be reduced significantly by providing mice with bicarbonate-containing drinking water. The peptide has three states: soluble in water, bound to the surface of a membrane, and inserted across the membrane as an α-helix. At physiological pH, the equilibrium is toward water, which explains its low affinity for cells in healthy tissue; at acidic pH, titration of Asp residues shifts the equilibrium toward membrane insertion and tissue accumulation. The replacement of two key Asp residues located in the transmembrane part of pHLIP by Lys or Asn led to the loss of pH-sensitive insertion into membranes of liposomes, red blood cells, and cancer cells in vivo, as well as to the loss of specific accumulation in tumors. pHLIP nanotechnology introduces a new method of detecting, targeting, and possibly treating acidic diseased tissue by using the selective insertion and folding of membrane peptides

    Photophysics of the electronic states S0 and S1 for the coplanar molecular structures of the α,ω-diphenylpolyenes DPH and DPO

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    Spectroscopy of the monoclinic and orthorhombic crystalline forms of all-trans-diphenylhexatriene (DPH) and all-trans-diphenyloctatetraene (DPO) show absorption and emission bands that do not generate the widely known Stokes shift of the polyene compounds, discovered by Hausser et al. in 1953 and repeatedly studied over the last 60 years. It can be concluded from our study that the crystallization system, whether in a monoclinic or orthorhombic system, does not significantly influence the photophysics of DPH and DPO in the crystal phas

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

    Nothing New in the (North) East? Interpreting the Rhetoric and Reality of Japanese Corporate Governance

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    Japan finally seems to be pulling itself out of its lost decade (and a half) of economic stagnation. Some grudgingly or triumphantly attribute this to micro-economic reforms, freeing up arthritic markets, although there is also evidence that macro-economic policy failures have been a major cause of poor performance since the 1990s. Many point to overlapping transformations in corporate governance, broadly defined to cover relationships among managers and employees as well as between firms and outside shareholders, creditors, and other stakeholders. These relationships are in flux, with moves arguably favouring shareholders and more market-driven control mechanisms. It has certainly been a found decade for law reform in Japan, particularly in corporate law, with a plethora of legislative amendments commencing around 1993 and culminating in the enactment of a consolidated Company Law in 2005. This modernisation project, particularly since 2001, is reportedly aimed at (i) securing better corporate governance, (ii) bringing the law into line with a highly-developed information society, (iii) liberalising fundraising measures, (iv) bringing corporate law into line with the internationalization of corporate activity, and (v) modernizing terms and consolidating corporate law. Because the suite of revisions has moved away from strict mandatory rules set out originally in Japan\u27s Commercial Code of 1899, modeled primarily on German law, another growing perception is that Japanese corporate law and practice is or will soon be converging significantly on US models. However, assessments remain divided as to whether these moves in corporate governance and capitalism more generally in Japan amount to a new paradigm or regime shift . Focusing primarily on quite influential commentary in English, Part I of this paper outlines two pairs of views. It concludes that the most plausible assessment is of significant but gradual transformation towards a more market-driven approach, evident also in other advanced political economies. Drawing more generally from these often virulently divided views, Part II sets out five ways forward through the proliferating literature and source material on corporate governance in Japan. Particular care must be taken in: (i) selecting the temporal timeframe, (ii) selecting countries to compare, (iii) balancing black-letter law and broader socio-economic context, (iv) reflecting on and disclosing normative preferences, and (v) giving weight to processes as well as outcomes, when assessing change in Japan - and any other country\u27s governance system. Part III ends with a call for further research particularly on law- and policy-producing processes, rather than mainly outcomes. It also outlines the usefulness of this analytical framework for analysing the broader field of Corporate Social Responsibility, now emerging as the next major area of debate and transformation in Japan - as elsewhere

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Nothing New in the (North) East? Interpreting the Rhetoric and Reality of Japanese Corporate Governance

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    Detection of collagen type II and proteoglycans in the synovial fluids of patients diagnosed with non-infectious knee joint synovitis indicates early damage to the articular cartilage matrix

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    Objective: We have sought to determine if markers of proteoglycans and collagen type II (CII) degradation can be detected at an early stage following acute knee injury in the synovial fluid (SF) from a group of patients diagnosed with non-infectious knee joint synovitis (KJS). CII, proteoglycans and elastase activity in the SF from patients with KJS were compared to SF from patients with two chronic arthritis conditions: osteoarthritis (OA) and rheumatoid arthritis (RA) as well as normal SF controls. Methods: CII peptides were measured by sandwich ELISA using two monoclonal antibodies: 8:6:D8, a CII-specific antibody, and 14:7:D8 which binds to an amino acid sequence on CII as well as collagens type I, III and V. Epitope 9A4, a neo-epitope resulting from collagenase digestion of CI, CII, and CIII was measured by inhibition ELISA. Proteoglycans measurement included total sulfated glycosaminoglycans (sGAG) by dye-binding assay and 5-D-4 epitope, a keratan sulfate epitope, by inhibition ELISA. Elastase activity was measured colorimetircally using N-succinyl trialanine p-nitroanilide (SANA) substrate. Results: The quantified CII peptide concentrations by sandwich and inhibition ELISA were significantly higher in SF from patients with KJS (P\u3c0.05) compared to SF from patients with OA, RA and normal aspirates. 5-D-4 and sGAG concentrations were significantly lower (P\u3c0.05) in SF from patients with KJS compared to SF from patients with OA and RA. Elastase activity in SF from patients with KJS and RA were significantly higher (P\u3c0.05) than SF from patients with OA. A significant correlation exists between elastase activity and 9A4 epitope concentration in SF from patients with KJS. Conclusion: The elevated CII peptides concentrations in KJS SF compared to normal and OA aspirates indicate early signs of cartilage network damage. The low proteoglycans concentrations in SF from patients with KJS may indicate that injury is limited to the superficial zone of cartilage in the patient population studied. The high elastase activity in SF from patients with KJS and RA are linked to the high CII peptides concentration. The elastase activity in the SF from patients with KJS is due to the action of neutrophil elastase (NE) and collagenases, where both contribute to the destruction of the articular cartilage. © 2003 Published by Elsevier Ltd on behalf of OsteoArthritis Research Society International
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