1,019 research outputs found

    Profiling inflammation and tissue injury markers in perfusate and bronchoalveolar lavage fluid during human ex vivo lung perfusion

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    OBJECTIVES: Availability of donor lungs suitable for transplant falls short of current demand and contributes to waiting list mortality. Ex vivo lung perfusion (EVLP) offers the opportunity to objectively assess and recondition organs unsuitable for immediate transplant. Identifying robust biomarkers that can stratify donor lungs during EVLP to use or non-use or for specific interventions could further improve its clinical impact. METHODS: In this pilot study, 16 consecutive donor lungs unsuitable for immediate transplant were assessed by EVLP. Key inflammatory mediators and tissue injury markers were measured in serial perfusate samples collected hourly and in bronchoalveolar lavage fluid (BALF) collected before and after EVLP. Levels were compared between donor lungs that met criteria for transplant and those that did not. RESULTS: Seven of the 16 donor lungs (44%) improved during EVLP and were transplanted with uniformly good outcomes. Tissue and vascular injury markers lactate dehydrogenase, HMGB-1 and Syndecan-1 were significantly lower in perfusate from transplanted lungs. A model combining IL-1b and IL-8 concentrations in perfusate could predict final EVLP outcome after 2 h assessment. In addition, perfusate IL-1b concentrations showed an inverse correlation to recipient oxygenation 24 h post-transplant. CONCLUSIONS: This study confirms the feasibility of using inflammation and tissue injury markers in perfusate and BALF to identify donor lungs most likely to improve for successful transplant during clinical EVLP. These results support examining this issue in a larger study

    Critical challenges for EUV resist materials

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    Although Extreme ultraviolet lithography (EUVL) is now well into the commercialization phase, critical challenges remain in the development of EUV resist materials. The major issue for the 22-nm half-pitch node remains simultaneously meeting resolution, line-edge roughness (LER), and sensitivity requirements. Although several materials have met the resolution requirements, LER and sensitivity remain a challenge. As we move beyond the 22-nm node, however, even resolution remains a significant challenge. Chemically amplified resists have yet to demonstrate the required resolution at any speed or LER for 16-nm half pitch and below. Going to non-chemically amplified resists, however, 16-nm resolution has been achieved with a LER of 2 nm but a sensitivity of only 70 mJ/cm{sup 2}

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Placental magnetic resonance imaging in chronic hypertension: A case-control study

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    Introduction We aimed to explore the use of magnetic resonance imaging (MRI) in vivo as a tool to elucidate the placental phenotype in women with chronic hypertension. Methods In case-control study, women with chronic hypertension and those with uncomplicated pregnancies were imaged using either a 3T Achieva or 1.5T Ingenia scanner. T2-weighted images, diffusion weighted and T1/T2* relaxometry data was acquired. Placental T2*, T1 and apparent diffusion coefficient (ADC) maps were calculated. Results 129 women (43 with chronic hypertension and 86 uncomplicated pregnancies) were imaged at a median of 27.7 weeks’ gestation (interquartile range (IQR) 23.9–32.1) and 28.9 (IQR 26.1–32.9) respectively. Visual analysis of T2-weighted imaging demonstrated placentae to be either appropriate for gestation or to have advanced lobulation in women with chronic hypertension, resulting in a greater range of placental mean T2* values for a given gestation, compared to gestation-matched controls. Both skew and kurtosis (derived from histograms of T2* values across the whole placenta) increased with advancing gestational age at imaging in healthy pregnancies; women with chronic hypertension had values overlapping those in the control group range. Upon visual assessment, the mean ADC declined in the third trimester, with a corresponding decline in placental mean T2* values and showed an overlap of values between women with chronic hypertension and the control group. Discussion A combined placental MR examination including T2 weighted imaging, T2*, T1 mapping and diffusion imaging demonstrates varying placental phenotypes in a cohort of women with chronic hypertension, showing overlap with the control group

    REVISE AND RESUBMIT Corporate Governance and Investor Rationality: Evidence from the 1990s' Technology Bubble

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    Several studies document irrational investor behavior related to Internet firms during the 1990s' technology bubble. This paper investigates whether investors display the same behavior towards nonInternet firms that adopt Internet technology in the same time period. I find a positive association between short-and long-term metrics of firm performance related to the launching of commercial web sites by non-Internet companies. However, the extent to which this positive association exists is largely driven by the quality of the firms' corporate governance. These results indicate that investors were not universally irrational during the 1990s technology bubble. In addition, my findings also highlight the relevance of corporate governance in mitigating information asymmetry when technological innovations with an uncertain impact on firm value affect the economy. Why did the launching of a commercial web site generate opposite market responses for two retailers in the same industry? Differences between the two firms, reported in Another difference of potential importance between ShopKo and Cost Plus is the level of protection these firms grant their shareholders as measured by the Gompers, Ishii, and Metrick 2 In this paper, I use a broad sample of firms to study whether, based on the way companies are governed, investors react differently to firms' adoptions of new technologies. I also study whether investors' reactions to the adoption of new technologies are rational. The 1990s technology bubble provides an excellent setting to study these research questions. This period witnessed the emergence of the Internet as new commercial medium. The efficacy of this new technology was the source of considerable uncertainty. Several finance studies, discussed in the next section, document irrational investor behavior around tech stocks during the 1990s technology bubble. 2 However, none of the existing studies document whether investors were universally irrational during the period. That is, whether the irrational behavior was limited to tech stocks or whether investors were able to moderate uncertainty and act rationally. To address my research questions, as in the case-study of ShopKo and Cost Plus, I examine the effect of launching a commercial web site during the 1990s on firm value in non-Internet companies. This choice is motivated by the notion that establishing a web site is a necessary --though not sufficient--condition for any firm in order to adopt and implement the new technology and perhaps conduct business on the Internet. 3 I recognize that results supporting irrational investor behavior might also be consistent with investors' short-term or myopic behavior, (Stein (1989)), and with the notion that stock prices fail to reflect future earnings 4 Both short-and long-term payoffs are necessary to test for rational investor behavior because, under efficient markets, one would only expect to observe meaningful short term stock revaluations for events that investors believe will have a lasting and positive effect on the firm's future cash flows and profitability. In addition, the study of short-and long-term performance metrics enables me to dispel concerns over myopic investor behavior. 2. For example, 3 My initial proxy for corporate governance is the G-index, which counts restrictions on shareholder rights. Therefore, a lower (higher) G-index is commonly interpreted to proxy for strong (weak) shareholder rights and stronger (weaker) governance quality. I am aware that the use of the Gindex as an appropriate proxy for corporate governance is also the subject of debate. In robustness tests, the G-index is replaced with alternative governance metrics which yield qualitatively similar results. Initial results show that, on average, investors receive the introduction of commercial web sites enthusiastically, but I also find that operating performance declines in the years following the launching. Taken together, these results suggest that investors were overly excited in their initial evaluation of the impact of web sites on firm value and profitability, and appear consistent with both irrational and myopic behavior by investors. However, further tests which incorporate corporate governance to the analysis, do not lend support to the either one of these conjectures and allow me to reject irrational and myopic behavior hypotheses. Subsequent analyses show that the extent to which investors react positively to web site introductions is largely driven by whether the firm's level of investor protection is strong. Moreover,

    Latest results from the SEMATECH Berkeley extreme ultraviolet microfield exposure tool

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    Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the 0.3 numerical aperture SEMATECH Berkeley MET operating as a resist and mask test center. Here they present an update on the tool summarizing some of the latest test and characterization results. they provide an update on the long-term aberration stability of the tool and present line-space imaging in chemically amplified photoresist down to the 20-nm half-pitch level. Although resist development has shown substantial progress in the area of resolution, line-edge-roughness (LER) remains a significant concern. Here we present a summary of recent LER performance results and consider the effect of mask contributors to the LER observed from the SEMATECH Berkeley microfield tool

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of ttt\overline{t}, W+bbW+b\overline{b} and W+ccW+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays WνW\rightarrow\ell\nu, where \ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
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