Novel phase diagram of superconductor NaxCoO2-yH2O in a 75 % relative humidity

We succeeded in synthesizing the powder samples of bilayer-hydrate sodium cobalt oxide superconductors NaxCoO2-yH2O with Tc = 0 ~ 4.6 K by systematically changing the keeping duration in a 75 % relative humidity atmosphere after intercalation of water molecules. From the magnetic measurements, we found that the one-day duration sample does not show any superconductivity down to 1.8 K, and that the samples kept for 2 ~ 7 days show superconductivity, in which Tc increases up to 4.6 K with increasing the duration. Tc and the superconducting volume fraction are almost invariant between 7 days and 1month duration. The 59Co NQR spectra indicate a systematic change in the local charge distribution on the CoO2 plane with change in duration.Comment: 4 pages, 5 figures, submitted to Journal of the Physical Society of Japa

Understanding Collaborations in Virtual World

Virtual worlds (VW) have paved a new and important channel for workplace collaborations. However, analysts have noted that several organizations that made a strong entrance into using VW as a nouveau channel for communication and collaboration are stepping back due to limited user response. Motivated by this fact, we propose a trust-theoretic ‘virtual world collaboration model’ for collaborations in virtual worlds. The model, grounded in literature on ‘technology adoption’ and ‘trust’, theoretically examines the role of trust in motivating users for using this rich virtual communication medium for collaborations. Results establish the important roles of perceived social presence and perceived structural assurance for fostering user trust in VW. Further, results also indicate that user trust is significantly related to both extrinsic and intrinsic motivations, which in turn influence the behavioural intention to use the VW. Implications for research and practice are discussed

A survey about postoperative delirium in older patients among nurses and anaesthetists:Implications for future practice and policy

Background Postoperative delirium is a major complication associated with anaesthesia and surgery, more commonly seen in older people. Aims The aims of this study were to explore the knowledge and understanding of anaesthetists and nurses involved in anaesthesia through their responses to two case scenarios of postoperative delirium experienced by older people. Methods A 30-item online survey was sent to 500 potential respondents. Results Two hundred and twenty-six practitioners from Australia, New Zealand and Scotland responded. Most had no workplace protocols for anaesthesia planning in older people. There was substantial variability in practice in relation to postoperative delirium screening, detection, prevention and management. Conclusions Improvements in education and awareness, together with a more coherent approach, for example, as recommended in the European Society of Anaesthesiology Guidelines, could help to reduce the impact of postoperative delirium in older people. This should be combined with ongoing research into perioperative optimisation of detection, prevention and management of postoperative delirium

Emergence of Anti-Cancer Drug Resistance: Exploring the Importance of the Microenvironmental Niche via a Spatial Model

Practically, all chemotherapeutic agents lead to drug resistance. Clinically, it is a challenge to determine whether resistance arises prior to, or as a result of, cancer therapy. Further, a number of different intracellular and microenvironmental factors have been correlated with the emergence of drug resistance. With the goal of better understanding drug resistance and its connection with the tumor microenvironment, we have developed a hybrid discrete-continuous mathematical model. In this model, cancer cells described through a particle-spring approach respond to dynamically changing oxygen and DNA damaging drug concentrations described through partial differential equations. We thoroughly explored the behavior of our self-calibrated model under the following common conditions: a fixed layout of the vasculature, an identical initial configuration of cancer cells, the same mechanism of drug action, and one mechanism of cellular response to the drug. We considered one set of simulations in which drug resistance existed prior to the start of treatment, and another set in which drug resistance is acquired in response to treatment. This allows us to compare how both kinds of resistance influence the spatial and temporal dynamics of the developing tumor, and its clonal diversity. We show that both pre-existing and acquired resistance can give rise to three biologically distinct parameter regimes: successful tumor eradication, reduced effectiveness of drug during the course of treatment (resistance), and complete treatment failure

Nasopharyngeal carcinoma: presenting symptoms and duration before diagnosis

This is a retrospective analysis of 4768 patients with undifferentiated or non-keratinising carcinoma of the nasopharynx who were treated during 1 January 1976 to 31 December 1985. The mean duration of symptoms before diagnosis was 8 months (range, 1-36 months for 95% of patients). A significant association between the duration of symptoms and the presenting stage was observed (P<0.001); 58% and 39% of stage I and stage V patients, respectively, reported as having had symptoms for less than 6 months. Of the later presenters (those having had symptoms for 6 months or longer), 89% were given a full course of radical megavoltage radiotherapy, but 6% were too advanced for any irradiation attempt. Consequently, the 10-year actuarial disease-specific survival was significantly higher among the early presenters: 48% versus 42% (P<0.001). The importance of early detection is emphasised.published_or_final_versio

Macrophages exposed continuously to lipopolysaccharide and other agonists that act via toll-like receptors exhibit a sustained and additive activation state

BACKGROUND: Macrophages sense microorganisms through activation of members of the Toll-like receptor family, which initiate signals linked to transcription of many inflammation associated genes. In this paper we examine whether the signal from Toll-like receptors [TLRs] is sustained for as long as the ligand is present, and whether responses to different TLR agonists are additive. RESULTS: RAW264 macrophage cells were doubly-transfected with reporter genes in which the IL-12p40, ELAM or IL-6 promoter controls firefly luciferase, and the human IL-1β promoter drives renilla luciferase. The resultant stable lines provide robust assays of macrophage activation by TLR stimuli including LPS [TLR4], lipopeptide [TLR2], and bacterial DNA [TLR9], with each promoter demonstrating its own intrinsic characteristics. With each of the promoters, luciferase activity was induced over an 8 hr period, and thereafter reached a new steady state. Elevated expression required the continued presence of agonist. Sustained responses to different classes of agonist were perfectly additive. This pattern was confirmed by measuring inducible cytokine production in the same cells. While homodimerization of TLR4 mediates responses to LPS, TLR2 appears to require heterodimerization with another receptor such as TLR6. Transient expression of constitutively active forms of TLR4 or TLR2 plus TLR6 stimulated IL-12 promoter activity. The effect of LPS, a TLR4 agonist, was additive with that of TLR2/6 but not TLR4, whilst that of lipopeptide, a TLR2 agonist, was additive with TLR4 but not TLR2/6. Actions of bacterial DNA were additive with either TLR4 or TLR2/6. CONCLUSIONS: These findings indicate that maximal activation by any one TLR pathway does not preclude further activation by another, suggesting that common downstream regulatory components are not limiting. Upon exposure to a TLR agonist, macrophages enter a state of sustained activation in which they continuously sense the presence of a microbial challenge

Charge order and superconductivity in a two-dimensional triangular lattice at n=2/3

To investigate the possibility of charge order and superconductivity in a doped two-dimensional triangular lattice, we study the extended Hubbard model with variational Monte Carlo method. At n=2/3, a commensurate filling for a triangular lattice, it is shown that the nearest-neighbor Coulomb interaction V induces honeycomb-type charge order and antiferromagnetic spin order at U>10t. We also discuss the possibility of superconductivity induced by charge fluctuation and the relation to the superconductivity in Na_{0.35}CoO_{2}1.3H_{2}O and theta-type organic condoctors.Comment: 4 pages, 5 figure

Carotene contents of processed meats blended with palm fats

(beef burgers and chicken frankfurters) blended with palm fats was studied. Alpha-carotene and β-carotene decreased significantly (P<0.05) by 62-66% and 72-80% respectively in beef burgers where the fats were substituted with red palm fat (RPF35) and a mixture of red palm fat and palm fat (FB) when the meats were stored at -18oC for 6 month after cooking. Alpha-carotene lost by 53% and 33% while beta-carotene by 67% and 47%, respectively in raw beef burger where the fats were replaced with RPF35 and FB After storage for 6 months (-18oC). Alpha-carotene concentrations lost by 66% and 62%, respectively in beef burger substituted with RPF35 and FB during storage for 6 months at -18oC after cooking. Alpha-carotene in retorted chicken frankfurter (RC) substituted with RPF48 only lost 25% while oven-cooked chicken frankfurter (OC) containing RPF48 lost 61%. Beta-carotene was degraded faster compared to α-carotene in RC, OC and cooked beef burger indicating that the beef burger was more stable after cooking and storage. Even though OC, RC frankfurters and cooked beef burgers substituted with red palm fat showed the highest percent loss in β-carotene concentrations after storage, the value retained was still the highest (23.0, 42.0 and 23.8 μg/g, respectively). In summary, the effect of processing, cooking, frozen storage and the type of fats used could influence the stability of alpha- and beta-carotenes and their content in meat products