239 research outputs found
Synthesis of Single Phase Hg-1223 High Tc Superconducting Films With Multistep Electrolytic Process
We report the multistep electrolytic process for the synthesis of high Tc
single phase HgBa2Ca2Cu3O8+ (Hg-1223) superconducting films. The
process includes : i) deposition of BaCaCu precursor alloy, ii) oxidation of
BaCaCu films, iii) electrolytic intercalation of Hg in precursor BaCaCuO films
and iv) electrochemical oxidation and annealing of Hg-intercalated BaCaCuO
films to convert into Hg1Ba2Ca2Cu3O8+ (Hg-1223). Films were
characterized by thermo-gravimetric analysis (TGA) and differential thermal
analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM).
The electrolytic intercalation of Hg in BaCaCuO precursor is proved to be a
novel alternative to high temperature-high pressure mercuration process. The
films are single phase Hg-1223 with Tc = 121.5 K and Jc = 4.3 x 104 A/cm2.Comment: 17 Pages, 10 Figures. Submitted to Superconductor Science and
Technolog
Phase II biomarker trial of a multimarker diagnostic for ovarian cancer
The primary hypothesis to be tested in this study was that the diagnostic performance (as assessed by the area under the receiver operator characteristic curve, AUC) of a multianalyte panel to correctly identify women with ovarian cancer was significantly greater than that for CA-125 alone
Do serum biomarkers really measure breast cancer?
Background
Because screening mammography for breast cancer is less effective for premenopausal women, we investigated the feasibility of a diagnostic blood test using serum proteins.
Methods
This study used a set of 98 serum proteins and chose diagnostically relevant subsets via various feature-selection techniques. Because of significant noise in the data set, we applied iterated Bayesian model averaging to account for model selection uncertainty and to improve generalization performance. We assessed generalization performance using leave-one-out cross-validation (LOOCV) and receiver operating characteristic (ROC) curve analysis.
Results
The classifiers were able to distinguish normal tissue from breast cancer with a classification performance of AUC = 0.82 ± 0.04 with the proteins MIF, MMP-9, and MPO. The classifiers distinguished normal tissue from benign lesions similarly at AUC = 0.80 ± 0.05. However, the serum proteins of benign and malignant lesions were indistinguishable (AUC = 0.55 ± 0.06). The classification tasks of normal vs. cancer and normal vs. benign selected the same top feature: MIF, which suggests that the biomarkers indicated inflammatory response rather than cancer.
Conclusion
Overall, the selected serum proteins showed moderate ability for detecting lesions. However, they are probably more indicative of secondary effects such as inflammation rather than specific for malignancy.United States. Dept. of Defense. Breast Cancer Research Program (Grant No. W81XWH-05-1-0292)National Institutes of Health (U.S.) (R01 CA-112437-01)National Institutes of Health (U.S.) (NIH CA 84955
The Influence of Radiographic Phenotype and Smoking Status on Peripheral Blood Biomarker Patterns in Chronic Obstructive Pulmonary Disease
Background: Chronic obstructive pulmonary disease (COPD) is characterized by both airway remodeling and parenchymal destruction. The identification of unique biomarker patterns associated with airway dominant versus parenchymal dominant patterns would support the existence of unique phenotypes representing independent biologic processes. A cross-sectional study was performed to examine the association of serum biomarkers with radiographic airway and parenchymal phenotypes of COPD. Methodology/Principal Findings: Serum from 234 subjects enrolled in a CT screening cohort was analyzed for 33 cytokines and growth factors using a multiplex protein array. The association of serum markers with forced expiratory volume in one second percent predicted (FEV1%) and quantitative CT measurements of airway thickening and emphysema was assessed with and without stratification for current smoking status. Significant associations were found with several serum inflammatory proteins and measurements of FEV1%, airway thickening, and parenchymal emphysema independent of smoking status. The association of select analytes with airway thickening and emphysema was independent of FEV1%. Furthermore, the relationship between other inflammatory markers and measurements of physiologic obstruction or airway thickening was dependent on current smoking status. Conclusions/Significance: Airway and parenchymal phenotypes of COPD are associated with unique systemic serum biomarker profiles. Serum biomarker patterns may provide a more precise classification of the COPD syndrome, provide insights into disease pathogenesis and identify targets for novel patient-specific biological therapies. © 2009 Bon et al
SME Performance, Innovation and Networking - Evidence on Complementarities for a Local Economic System
The paper addresses the relevancy of networking activities and R&D as main drivers of productivity performance and ouput innovation, for small and medium enterprises (SME) playing in a local economic system. Given the intangible nature of many techno organisational innovation and networking strategies, original recent survey data for manufacturing and services are exploited. The aim is to provide new evidence on the complementarity relationships concerning different networking activities and R&D in a local SME oriented system in Northern Italy. We first introduce a methodological framework to empirically test complementarity among R&D and networking, in a discrete setting. Secondly, we consequently present empirical evidence on productivity drivers and on complementarity between R&D and networking strategies, with respect to firm productivity and process/product output innovation. R&D is a main driver of innovation and productivity, even without networking. This may signify, in association with the evidence on complementarity, that firm expenditures on R&D are a primary driver for performance. The complementarity with networking is a consequential step. Networking by itself cannot thus play a role in stimulating productivity and innovation. It can be a complementary factor in situations where cooperation and networking are needed to achieve economies of scale and/or to merge and integrate diverse skills, technologies and competencies. This is compatible with a framework where networking is the public good part of an impure public good wherein R&D plays the part of the private-led driving force towards structural break from the business as usual scenario. Managers and policy makers should be aware that in order to exploit asset complementarity, possibly transformed into competitive advantages, both R&D and networking are to be sustained and favoured. our evidence suggests that R&D may be a single main driver of performance. Since R&D expenditures are associated with firm size, a policy sustain is to be directed towards firm enlargement. After a certain threshold firms have the force to increase expenditures. The size effect is nevertheless non monotonous. Then, but not least important, for the majority of firms still remaining under a critical size threshold, policy incentives should be directed to R&D in connection with networking, through which a virtuous circle may arise. It is worth noting that it is not networking as such the main engine. Networking elements are crucially linked to innovation dynamics; it is nevertheless innovation that explains and drives networking, and not the often claimed mere existence of local spillovers or of a civic associative culture in the territory. Such public good factors exist but are likely to evolve with and be sustained by firm innovative dynamics
Alliances and the innovation performance of corporate and public research spin-off firms
We explore the innovation performance benefits of alliances for spin-off firms, in particular spin-offs either from other firms or from public research organizations. During the early years of the emerging combinatorial chemistry industry, the industry on which our empirical analysis focuses, spin-offs engaged in alliances with large and established partners, partners of similar type and size, and with public research organizations, often for different reasons. We seek to understand to what extent alliances of spin-offs with other firms (either large- or small- and medium-sized firms) affected their innovation performance and also how this performance may have been affected by their corporate or public research background. We find evidence that in general alliances of spin-offs with other firms, in particular alliances with large firms, increased their innovation performance. Corporate spin-offs that formed alliances with other firms outperformed public research spin-offs with such alliances. This suggests that, in terms of their innovation performance, corporate spin-offs that engaged in alliances with other firms seemed to have benefitted from their prior corporate background. Interestingly, it turns out that the negative impact of alliances on the innovation performance of public research spin-offs was largely affected by their alliances with small- and medium-sized firms
Social Security, Labour Market and Restructuring: Current Situation and Expected Outcomes of Reforms
The paper focuses on the social safety nets in Russian Federation and Ukraine in the view of changes on the labour market since the beginning of economic transition. We showed that many past phenomena (e.g. restructuring of the economy, wage and pension arrears, new groups at-risk-of-poverty, demographic transition) caused a need to change an old type social safety net (SSN) into the new one, better adapted to emerging more liberal economy problems. Additionally, we analysed some gender specific issues related to social security that are caused mainly by inequalities in the labour market. Differences of earnings between men and women in Russia caused by sector segregation account for seem to be more important than the gap between gender earnings attributed to the position. In Ukraine the main contributors to gross gender differential of log earnings (that equals to 32%) explained by our model are sector segregation and occupation. We also pointed out to future policy challenges in the area of social security systems in both countries. The retirement reforms introduced recently are a step in the right direction, although their impact will not be felt for a number of years. Other reforms, with more immediate results, are necessary. Social safety nets should be made more efficient and social benefits should be better targeted
INFRARED AND RAMAN STUDY OF NEW TYPES OF ROTATIONAL ISOMERISM IN ORGANOMETALLIC COMPOUNDS OF TRANSITION METALS
Author Institution: A.N. Nesmeyanov Institute of Organoelement compounds, Russian Academy of ScienceA hindered internal rotation in the molecules of organometallic compounds of transition metals in organic and liquified noble gas solutions was studied using FTIR and Raman spectroscopy in a wide temperature range. It was demonstrated that rotational exist due to the internal rotation about single bonds between the transition metal and carbon atoms (in ``staircase” carbonyl pi-complexes of Fe, Mn, Cr, Mo, W), transition metal and non-transition element (in the complexes Cp(Co)2Fe X2R and [Cp(Co)2Fe]2X2, = Ge, Sn Cp = cyclopentadienyl), and between two transition metals (in binuclear complexes [Cp(CO)2M]2), M = Fe, Ru). The rotation of the M[CO)3- fragment was found in the ferrol type clusters of Ru and Re, where this group is pi-coordinated to the double bonds of metallacyclopentadienyl ring. The influence of different factors on the energy difference between rotational and on the rotational barriers is discussed
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