Progress in the determination of the J/ψ−πJ/\psi-\pi cross section

Improving previous calculations, we compute the $J/\psi \pi\to {charmed mesons}$ cross section using QCD sum rules. Our sum rules for the $J/\psi \pi\to \bar{D} D^*$, $D \bar{D}^*$, ${\bar D}^* D^*$ and ${\bar D} D$ hadronic matrix elements are constructed by using vaccum-pion correlation functions, and we work up to twist-4 in the soft-pion limit. Our results suggest that, using meson exchange models is perfectly acceptable, provided that they include form factors and that they respect chiral symmetry. After doing a thermal average we get $\sim 0.3$ mb at T=150\MeV.Comment: 22 pages, RevTeX4 including 7 figures in ps file

Measurement of Cosmic-ray Muon-induced Spallation Neutrons in the Aberdeen Tunnel Underground Laboratory

AbstractMuon-induced neutrons are one of the major backgrounds to various underground experiments, such as dark matter searches, low-energy neutrino oscillation experiments and neutrino-less double beta-decay experiments. Previous experiments on the underground production rate of muon-induced neutrons were mostly carried out either at shallow sites or at very deep sites. The Aberdeen Tunnel experiment aims to measure the neutron production rate at a moderate depth of 611 meters water equivalent. Our apparatus comprises of six layers of plastic-scintillator hodoscopes for tracking the incident cosmic-ray muons, and 760 L of gadolinium-doped liquid-scintillator for both neutron production and detection targets. In this paper, we describe the design and the performance of the apparatus. The preliminary result on the measurement of neutron production rate is also presented

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Polymers for organic electronics

Scientists have found π-conjugated polymers as an exciting area of scientific research in organic electronics and photonics and the development has gone through several evolutional stages. They can exhibit an array of useful materials properties, such as light emission, luminescent sensing, ferromagnetism, photoconductivity and photovoltaic effect, and more. Bulk heterojunctions (BHJs) made from bicontinuous polymer-fullerene donor-acceptor composites at the nanometer length scale are currently the main configuration for highly efficient PSCs. The BHJs are typically fabricated by sandwiching a thin film of photoactive polymers between two electrodes. Polymer Light-Emitting Diodes (PLEDs) are devices composed of thin films containing polymer molecules that directly convert electricity into light. Organic thin-film transistors (OTFTs) have become one of the most important components of organic electronics and are key building blocks in the context of large-area, flexible and ultralow-cost electronics

A novel approach to the growth analysis of hamster secondary palate by histone 3 m RNA in situ hybridiration

A study was undertaken to determine the cell proliferation kinetics during the development of hamster vertical palatal shelf ad initium. Harnster embryo heads, obtained at different times between days 10 and 12 of gestation (which is the period of vertical shelf development) were processed and sectioned to localize histone 3 mRNA, a cell cycle specific gene, by in situ hybridization. Sense and antisense 35~-labelledh istone 3 riboprobes were used as hybridization probes. Percent labelled cells were determined. The results showed that a high rate of random proliferation of both epithelial and mesenchymal cells was a major component of early vertical palatal growth. Subsequently, during the latter half of vertical shelf development, the proliferation rates of the epithelial and mesenchymal cells were different in a region specific manner. It was suggested that the spatio-temporal changes in the distribution of cycling mesenchymal and epithelial cells during vertical palate development may indicate their heterogeneity for subsequent segregation into appropnate phenotypes

Organic nanoparticles with aggregation-induced emission for tracking bone marrow stromal cells in the rat ischemic stroke model

Organic nanoparticles (NPs) with aggregation-induced emission (AIE) have been successfully used for tracking bone marrow stromal cells (BMSCs) in rats with ischemic stroke, highlighting the great potential of such fluorescent NPs in understanding the fate of transplanted stem cells for cell-based therapies

Solid-state synthesis and characterisation of mesoporous zirconia with lamellar and wormhole-like mesostructures

Mesostructured zirconia with lamellar and wormhole-like mesostructure was synthesized using a solid-state reaction route. Ordered lamellar mesostructure is achieved at low OH–/Zr ratio; while high OH–/Zr ratio leads to less ordered wormhole-like mesostructure. The varying synthesis conditions result in different inorganic frameworks with amorphous (in lamellar mesostructure) or tetragonal phase pore walls with different thermal stability. The surface area and pore structure of zirconia prepared by this method can be tailored using simple synthesis parameters such as OH–/Zr ratio and crystallization temperature. High surface area up to 716 m2/g can be achieved in the lamellar structured zirconia. However, the wormhole- like structured zirconia possesses high thermal stability. The results strongly suggest that in solid-state synthesis system mesostructure formation still follows the supramolecular self-assembly mechanism. In such synthesis system, the lamellar and reverse hexagonal structure can be transformed at different OH–/Zr ratios in order to minimize the surface energy of the mesophases formed