10,960 research outputs found

    Orbital superfluidity in the PP-band of a bipartite optical square lattice

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    The successful emulation of the Hubbard model in optical lattices has stimulated world wide efforts to extend their scope to also capture more complex, incompletely understood scenarios of many-body physics. Unfortunately, for bosons, Feynmans fundamental "no-node" theorem under very general circumstances predicts a positive definite ground state wave function with limited relevance for many-body systems of interest. A promising way around Feynmans statement is to consider higher bands in optical lattices with more than one dimension, where the orbital degree of freedom with its intrinsic anisotropy due to multiple orbital orientations gives rise to a structural diversity, highly relevant, for example, in the area of strongly correlated electronic matter. In homogeneous two-dimensional optical lattices, lifetimes of excited bands on the order of a hundred milliseconds are possible but the tunneling dynamics appears not to support cross-dimensional coherence. Here we report the first observation of a superfluid in the PP-band of a bipartite optical square lattice with SS-orbits and PP-orbits arranged in a chequerboard pattern. This permits us to establish full cross-dimensional coherence with a life-time of several ten milliseconds. Depending on a small adjustable anisotropy of the lattice, we can realize real-valued striped superfluid order parameters with different orientations Px±PyP_x \pm P_y or a complex-valued Px±iPyP_x \pm i P_y order parameter, which breaks time reversal symmetry and resembles the π\pi-flux model proposed in the context of high temperature superconductors. Our experiment opens up the realms of orbital superfluids to investigations with optical lattice models.Comment: 5 pages, 5 figure

    Do rural migrants 'float' in urban China? Neighbouring and neighbourhood sentiment in Beijing

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    Urban China reached 50% of the nation’s population by 2010, mainly as a result of massive rural–urban migration. There is substantial evidence of their social marginality in terms of occupational and housing opportunities. Here we ask about their incorporation into the neighbourhoods where they live. Rural migrants are called the ‘floating population’ in China, suggesting that their residence in the city is only temporary and that they are unlikely to develop strong local ties. This study contrasts the neighbourhood socialising of migrant tenants with that of urban homeowners who were born in the city. It draws on original survey research in Beijing that included questions on relations with neighbours and neighbourhood sentiment. It is found that migrants are more likely to engage in socialising and exchange of help with neighbours, and consequently their neighbouring helps strengthen their sentiment towards the neighbourhoods where they live. It is argued that contemporary social changes – including rising education and homeownership – may actually reduce neighbouring, while rural migrants’ marginality makes them more dependent on their local social network

    Comparing the Effect of Concept Mapping and Conventional Methods on Nursing Students' Practical Skill Score

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    Background: Development of practical skills in the field of nursing education has remained a serious and considerable challenge in nursing education. Moreover, newly graduated nurses may have weak practical skills, which can be a threat to patients’ safety. Objectives: The present study was conducted to compare the effect of concept mapping and conventional methods on nursing students’ practical skills. Patients and Methods: This quasi-experimental study was conducted on 70 nursing students randomly assigned into two groups of 35 people. The intervention group was taught through concept mapping method, while the control group was taught using conventional method. A two-part instrument was used including a demographic information form and a checklist for direct observation of procedural skills. Descriptive statistics, chi-square, independent samples t-tests and paired t-test were used to analyze data. Results: Before education, no significant differences were observed between the two groups in the three skills of cleaning (P = 0.251), injection (P = 0.185) and sterilizing (P = 0.568). The students mean scores were significantly increased after the education and the difference between pre and post intervention of students mean scores were significant in the both groups (P < 0.001). However, after education, in all three skills the mean scores of the intervention group were significantly higher than the control group (P < 0.001). Conclusions: Concept mapping was superior to conventional skill teaching methods. It is suggested to use concept mapping in teaching practical courses such as fundamentals of nursing

    Molecular Cloning of a New Immunomodulatory Protein from Anoectochilus formosanus which Induces B Cell IgM Secretion through a T-Independent Mechanism

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    An immunomodulatory protein (IPAF) was purified and cloned from Anoectochilus formosanus, an Orchidaceae herbal plant in Asia. The major targeting immune cells of IPAF and its modulating effects toward B lymphocytes were investigated. Rapid amplification of cDNA ends (RACE) was conducted to clone the IPAF gene, and the obtained sequence was BLAST compared on the NCBI database. MACS-purified mouse T and B lymphocytes were stimulated with IPAF and the cell proliferation, activation, and Igs production were examined. IPAF comprised a 25 amino acids signal peptide and a 138 amino acids protein which was homologous to the lectins from Orchidaceae plant. IPAF selectively induced the cell proliferation in mouse splenic B lymphocytes but not T lymphocytes. The IPAF-induced B cells exhibited increased CD69 and MHC class II expression, and a dose- and time-dependent enhancement in IgM production. These results suggested potential benefits of IPAF to strengthen the humoral immunity

    Elevated Paracellular Glucose Flux across Cystic Fibrosis Airway Epithelial Monolayers Is an Important Factor for Pseudomonas aeruginosa Growth.

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    People with cystic fibrosis (CF) who develop related diabetes (CFRD) have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL) of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR)-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE) monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps. aeruginosa growth and respiratory infection in CF disease

    Friction and wear properties of nano-Si<inf>3</inf>N<inf>4</inf>/nano-SiC composite under nanolubricated conditions

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    Friction and wear properties of nano-Si3N4/nano-SiC composite were studied under nanolubricated conditions. Mineral oil mixed with nanoparticles of diamond was used as lubricant. A friction coefficient of 0.043 and a wear coefficient of 4.2×10-7 were obtained for nano-Si3N4/nano-SiC composite under normal load of 600 N with mineral oil + 0.5 wt% nanodiamond, whereas a friction coefficient of 0.077 and a wear coefficient of 10.3×10-7 were obtained for nano-Si3N4/nano-SiC composite under normal load of 600 N with mineral oil. 3D surface profilometer was used to study the surface morphology of wear scars. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were conducted to illustrate reduction in friction and wear

    Microbial fuel cells: a green and alternative source for bioenergy production

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    Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

    Safety and feasibility of ultrasound-triggered targeted drug delivery of doxorubicin from thermosensitive liposomes in liver tumours (TARDOX): a single-centre, open-label, phase 1 trial

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    BACKGROUND: Previous preclinical research has shown that extracorporeal devices can be used to enhance the delivery and distribution of systemically administered anticancer drugs, resulting in increased intratumoural concentrations. We aimed to assess the safety and feasibility of targeted release and enhanced delivery of doxorubicin to solid tumours from thermosensitive liposomes triggered by mild hyperthermia, induced non-invasively by focused ultrasound. METHODS: We did an open-label, single-centre, phase 1 trial in a single UK hospital. Adult patients (aged ≥18 years) with unresectable and non-ablatable primary or secondary liver tumours of any histological subtype were considered for the study. Patients received a single intravenous infusion (50 mg/m2) of lyso-thermosensitive liposomal doxorubicin (LTLD), followed by extracorporeal focused ultrasound exposure of a single target liver tumour. The trial had two parts: in part I, patients had a real-time thermometry device implanted intratumourally, whereas patients in part II proceeded without thermometry and we used a patient-specific model to predict optimal exposure parameters. We assessed tumour biopsies obtained before and after focused ultrasound exposure for doxorubicin concentration and distribution. The primary endpoint was at least a doubling of total intratumoural doxorubicin concentration in at least half of the patients treated, on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT02181075, and is now closed to recruitment. FINDINGS: Between March 13, 2015, and March 27, 2017, ten patients were enrolled in the study (six patients in part I and four in part II), and received a dose of LTLD followed by focused ultrasound exposure. The treatment resulted in an average increase of 3·7 times in intratumoural biopsy doxorubicin concentrations, from an estimate of 2·34 μg/g (SD 0·93) immediately after drug infusion to 8·56 μg/g (5·69) after focused ultrasound. Increases of two to ten times were observed in seven (70%) of ten patients, satisfying the primary endpoint. Serious adverse events registered were expected grade 4 transient neutropenia in five patients and prolonged hospital stay due to unexpected grade 1 confusion in one patient. Grade 3-4 adverse events recorded were neutropenia (grade 3 in one patient and grade 4 in five patients), and grade 3 anaemia in one patient. No treatment-related deaths occurred. INTERPRETATION: The combined treatment of LTLD and non-invasive focused ultrasound hyperthermia in this study seemed to be clinically feasible, safe, and able to enhance intratumoural drug delivery, providing targeted chemo-ablative response in human liver tumours that were refractory to standard chemotherapy. FUNDING: Oxford Biomedical Research Centre, National Institute for Health Research

    Safety, tumor trafficking and immunogenicity of chimeric antigen receptor (CAR)-T cells specific for TAG-72 in colorectal cancer.

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    BackgroundT cells engineered to express chimeric antigen receptors (CARs) have established efficacy in the treatment of B-cell malignancies, but their relevance in solid tumors remains undefined. Here we report results of the first human trials of CAR-T cells in the treatment of solid tumors performed in the 1990s.MethodsPatients with metastatic colorectal cancer (CRC) were treated in two phase 1 trials with first-generation retroviral transduced CAR-T cells targeting tumor-associated glycoprotein (TAG)-72 and including a CD3-zeta intracellular signaling domain (CART72 cells). In trial C-9701 and C-9702, CART72 cells were administered in escalating doses up to 1010 total cells; in trial C-9701 CART72 cells were administered by intravenous infusion. In trial C-9702, CART72 cells were administered via direct hepatic artery infusion in patients with colorectal liver metastases. In both trials, a brief course of interferon-alpha (IFN-α) was given with each CART72 infusion to upregulate expression of TAG-72.ResultsFourteen patients were enrolled in C-9701 and nine in C-9702. CART72 manufacturing success rate was 100% with an average transduction efficiency of 38%. Ten patients were treated in CC-9701 and 6 in CC-9702. Symptoms consistent with low-grade, cytokine release syndrome were observed in both trials without clear evidence of on target/off tumor toxicity. Detectable, but mostly short-term (≤14&nbsp;weeks), persistence of CART72 cells was observed in blood; one patient had CART72 cells detectable at 48&nbsp;weeks. Trafficking to tumor tissues was confirmed in a tumor biopsy from one of three patients. A subset of patients had 111Indium-labeled CART72 cells injected, and trafficking could be detected to liver, but T cells appeared largely excluded from large metastatic deposits. Tumor biomarkers carcinoembryonic antigen (CEA) and TAG-72 were measured in serum; there was a precipitous decline of TAG-72, but not CEA, in some patients due to induction of an interfering antibody to the TAG-72 binding domain of humanized CC49, reflecting an anti-CAR immune response. No radiologic tumor responses were observed.ConclusionThese findings demonstrate the relative safety of CART72 cells. The limited persistence supports the incorporation of co-stimulatory domains in the CAR design and the use of fully human CAR constructs to mitigate immunogenicity

    Newborn Genetic Screening for Hearing Impairment: A Preliminary Study at a Tertiary Center

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    Universal newborn hearing screening (UNHS) is of paramount importance for early identification and management of hearing impairment in children. However, infants with slight/mild, progressive, or late-onset hearing impairment might be missed in conventional UNHS. To investigate whether genetic screening for common deafness-associated mutations could assist in identifying these infants, 1017 consecutive newborns in a tertiary hospital were subjected to both newborn hearing screening using a two-step distortion-product otoacoustic emissions (DPOAE) screening and newborn genetic screening (NGS) for deafness. The NGS targeted 4 deafness-associated mutations commonly found in the Taiwanese population, including p.V37I (c.109G>A) and c.235delC of the GJB2 gene, c.919-2A>G of the SLC26A4 gene, and mitochondrial m.1555A>G of the 12S rRNA gene. The results of the NGS were then correlated to the results of the NHS. Of the 1017 newborns, 16 (1.6%) had unilateral DPOAE screening failure, and 22 (2.2%) had bilateral DPOAE screening failure. A total of 199 (19.6%) babies were found to have at least 1 mutated allele on the NGS for deafness, 11 (1.1%) of whom were homozygous for GJB2 p.V37I, 6 (0.6%) compound heterozygous for GJB2 p.V37I and c.235delC, and 1 (0.1%) homoplasmic for m.1555A>G, who may potentially have hearing loss. Among them, 3 babies, 5 babies, and 1 baby, respectively, passed the NHS at birth. Comprehensive audiological assessments in the 9 babies at 3 months identified 1 with slight hearing loss and 2 with mild hearing loss. NGS for common deafness-associated mutations may identify infants with slight/mild or potentially progressive hearing impairment, thus compensating for the inherent limitations of the conventional UNHS
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