151 research outputs found

    Equation of motion approach to the Hubbard model in infinite dimensions

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    We consider the Hubbard model on the infinite-dimensional Bethe lattice and construct a systematic series of self-consistent approximations to the one-particle Green's function, G(n)(ω), n=2,3, G^{(n)}(\omega),\ n=2,3,\dots\ . The first n1n-1 equations of motion are exactly fullfilled by G(n)(ω)G^{(n)}(\omega) and the nn'th equation of motion is decoupled following a simple set of decoupling rules. G(2)(ω)G^{(2)}(\omega) corresponds to the Hubbard-III approximation. We present analytic and numerical results for the Mott-Hubbard transition at half filling for n=2,3,4n=2,3,4.Comment: 10pager, REVTEX, 8-figures not available in postscript, manuscript may be understood without figure

    Primary healthcare policy and vision for community pharmacy and pharmacists in Germany.

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    Germany is the highest populated country in Europe with a population of 82.3 million in 2019. As in many other developed countries, it has an aging population. Approximately 10% of the gross domestic product is spent on healthcare. The healthcare system is characterized by its accessibility. Patients are generally free to choose their primary care physicians, both family doctors and specialists, pharmacy, dentist, or emergency service. Up to a certain income, health insurance is mandatory with the statutory health insurance (SHI) system, covering 88% of the population. Major challenges are the lack of cooperation and integration between the different sectors and healthcare providers. This is expected to change with the introduction of a telematic infrastructure that is currently being implemented. It will not only connect all providers in primary and secondary care in a secure network but will also enable access to patients' electronic record/medical data and at the same time switch from paper to electronic prescriptions. Approximately 52,000 of the 67,000 pharmacists are working in approximately 19,000 community pharmacies. These pharmacies are owner-operated by a pharmacist. Pharmacists may own up to three subsidiaries nearby to their main pharmacy. Community pharmacy practice mainly consists of dispensing drugs, counselling patients on drug therapy and safety, and giving advice on lifestyle and healthy living. Many cognitive pharmaceutical services have been developed and evaluated in the past 20 years. Discussions within the profession and with stakeholders on the national level on the roles and responsibilities of pharmacists have resulted in nationally agreed guidelines, curricula, and services. However, cognitive services remunerated by the SHI funds on the national level remain to be negotiated and sustainably implemented. A law passed in November 2020 by parliament will regulate the remuneration of pharmaceutical services by the SHI funds with an annual budget of EUR 150 million. The type of services and their remuneration remain to be negotiated in 2021. The profession has to continue on all levels to advocate for a change in pharmacy practice by introducing pharmacy services into routine care

    Contrasting soil organic matter properties of a Hawaiian Andosol revealed by fractionations procedures

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    Volcanic Andosols are recognized by their strong capacity to accumulate soil organic carbon (SOC), and for presenting a singular aggregation pattern. However, the factors that govern their SOC storage and aggregation hierarchy are still poorly understood. In this way, the objective of this study was to evaluate the soil organic matter (SOM) properties of an Andosol through CN analysis, NMR spectroscopy, and scanning electron microscopy (SEM) with subsequent nano scale secondary ion mass spectrometry (NanoSIMS) analysis in the soil mineral fraction testing different fractionation methods. We tested three Andosol samples from two sites of the Kohala region – Hawaii with contrasting precipitation levels. The samples tested were as follow: 1784-60, 1784-80 and 2286-50 (precipitation - average depth in cm). We performed the SOM fractionation using ultrasonic dispersion at 1500 J ml-1, wet sieving and sedimentation. The procedure was carried out in three sets: in deionized water, in 1M NaCL solution, and in polytungstate solution (SPT) 1.8 g cm-3. Six fractions were obtained as follow: free particulate organic matter (fPOM), occluded particulate organic matter (oPOM), 4000-63, 63-20, 20-2 and < 2µm, respectively. Overall, the pre-dispersion treatment with NaCL saturation did not influence the C content and its distribution, as well as the SOM composition observed by NMR and NanoSIMS analysis. The oPOM fraction revealed great differences between the contrasting samples 1784-60 and 2286-50 in C content and SOM composition. More than 90% of the soil mass was concentrated in the fractions below 20 µm. The <2µm fraction was the most representative for the evaluated Andosol, accounting with 83% of the C content and 74% of the soil mass for the three samples evaluated overall. The 2286-50 presented a higher C content than the other samples especially for fPOM and the < 2 µm fraction. The 2286-50 sample presented overall a dominance of alkyl-C, while 1784-60 showed higher amounts of carboxyl-C and O/N alkyl groups, which can be explained by differences in the mineral composition of each sample. In addition, the NanoSIMS analysis demonstrated distinct spatial differences in the distribution of 12C- and 12C14N- in organo-mineral associations at the micro scale between the two sites. The results of this study suggest that mineral interactions in the smaller size-fractions (<2µm) can be the key to explain the mechanisms of C storage in Andosols

    Loss of BCL9/9l suppresses Wnt driven tumourigenesis in models that recapitulate human cancer.

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    Different thresholds of Wnt signalling are thought to drive stem cell maintenance, regeneration, differentiation and cancer. However, the principle that oncogenic Wnt signalling could be specifically targeted remains controversial. Here we examine the requirement of BCL9/9l, constituents of the Wnt-enhanceosome, for intestinal transformation following loss of the tumour suppressor APC. Although required for Lgr5+ intestinal stem cells and regeneration, Bcl9/9l deletion has no impact upon normal intestinal homeostasis. Loss of BCL9/9l suppressed many features of acute APC loss and subsequent Wnt pathway deregulation in vivo. This resulted in a level of Wnt pathway activation that favoured tumour initiation in the proximal small intestine (SI) and blocked tumour growth in the colon. Furthermore, Bcl9/9l deletion completely abrogated β-catenin driven intestinal and hepatocellular transformation. We speculate these results support the just-right hypothesis of Wnt-driven tumour formation. Importantly, loss of BCL9/9l is particularly effective at blocking colonic tumourigenesis and mutations that most resemble those that occur in human cancer

    Lagrangian Becchi-Rouet-Stora-Tyutin treatment of collective coordinates

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    The Becchi-Rouet-Stora-Tyutin (BRST) treatment for the quantization of collective coordinates is considered in the Lagrangian formalism. The motion of a particle in a Riemannian manifold is studied in the case when the classical solutions break a non-abelian global invariance of the action. Collective coordinates are introduced, and the resulting gauge theory is quantized in the BRST antifield formalism. The partition function is computed perturbatively to two-loops, and it is shown that the results are independent of gauge-fixing parameters.Comment: LaTeX file, 26 pages, PostScript figures at end of fil

    Proposal for taking data with the KLOE-2 detector at the DAΦ\PhiNE collider upgraded in energy

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    This document reviews the physics program of the KLOE-2 detector at DAΦ\PhiNE upgraded in energy and provides a simple solution to run the collider above the ϕ\phi-peak (up to 2, possibly 2.5 GeV). It is shown how a precise measurement of the multihadronic cross section in the energy region up to 2 (possibly 2.5) GeV would have a major impact on the tests of the Standard Model through a precise determination of the anomalous magnetic moment of the muon and the effective fine-structure constant at the MZM_Z scale. With a luminosity of about 103210^{32}cm2^{-2}s1^{-1}, DAΦ\PhiNE upgraded in energy can perform a scan in the region from 1 to 2.5 GeV in one year by collecting an integrated luminosity of 20 pb1^{-1} (corresponding to a few days of data taking) for single point, assuming an energy step of 25 MeV. A few years of data taking in this region would provide important tests of QCD and effective theories by γγ\gamma\gamma physics with open thresholds for pseudo-scalar (like the η\eta'), scalar (f0,f0f_0,f'_0, etc...) and axial-vector (a1a_1, etc...) mesons; vector-mesons spectroscopy and baryon form factors; tests of CVC and searches for exotics. In the final part of the document a technical solution for the energy upgrade of DAΦ\PhiNE is proposed.Comment: 19 pages, 8 figure

    Orbital Physics in the Perovskite Ti Oxides

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    In the perovskite Ti oxide RTiO3 (R=rare-earth ions), the Ti t2g orbitals and spins in the 3d^1 state couple each other through the strong electron correlations, resulting in a rich variety of orbital-spin phases. The origin and nature of orbital-spin states of these Mott insulators have been intensively studied. In this article, we review the studies on orbital physics in the perovskite titanates. We focus on the following three topics: (1) the origin and nature of the ferromagnetism as well as the orbital ordering in the compounds with relatively small R ions such as GdTiO3 and YTiO3, (2) the origin of the G-type antiferromagnetism and the orbital state in LaTiO3, and (3) the orbital-spin structures in other AFM(G) compounds with relatively large R ions (R=Ce, Pr, Nd and Sm). On the basis of these discussions, we discuss the whole phase diagram together with mechanisms of the magnetic phase transition. We also show that the Ti t2g degeneracy is inherently lifted in the titanates, which allows the single-band descriptions of the ground-state and low-energy electronic structures as a good starting point. Our analyses indicate that these compounds offer touchstone materials described by the single-band Hubbard model on the cubic lattice. From this insight, we also reanalyze the hole-doped titanates. Experimentally revealed filling-dependent and bandwidth-dependent properties and the critical behavior of the metal-insulator transitions are discussed in the light of theories based on the single-band Hubbard models.Comment: Review article, 26 pages, to appear in New Journal of Physic

    Short-term prognostic implications of serum and urine neutrophil gelatinase-associated lipocalin in acute heart failure:findings from the AKINESIS study

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    AIMS: Kidney impairment has been associated with worse outcomes in acute heart failure (AHF), although recent studies challenge this association. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel biomarker of kidney tubular injury. Its prognostic role in AHF has not been evaluated in large cohorts. The present study aimed to determine if serum NGAL (sNGAL) or urine NGAL (uNGAL) is superior to creatinine for predicting short-term outcomes in AHF. METHODS AND RESULTS: The study was conducted in an international, multicentre, prospective cohort consisting of 927 patients with AHF. Admission and peak values of sNGAL, uNGAL and uNGAL/urine creatinine (uCr) ratio were compared to admission and peak serum creatinine (sCr). The composite endpoints were death, initiation of renal replacement therapy, heart failure (HF) readmission and any emergent HF-related outpatient visit within 30 and 60 days, respectively. The mean age of the cohort was 69 years and 62% were male. The median length of stay was 6 days. The composite endpoint occurred in 106 patients and 154 patients within 30 and 60 days, respectively. Serum NGAL was more predictive than uNGAL and the uNGAL/uCr ratio but was not superior to sCr (area under the curve [AUC]; admission sNGAL 0.61 [95% confidence interval (CI) 0.55-0.67] and 0.59 [95% CI 0.54-0.65], peak sNGAL 0.60 [95% CI 0.54-0.66] and 0.57 [95% CI 0.52-0.63], admission sCr 0.60 [95% CI 0.54-0.64] and 0.59 [95% CI 0.53-0.64] [area under the curve: admission sNGAL 0.61, 95% confidence interval (CI) 0.55-0.67, and 0.59, 95% CI 0.54-0.65; peak sNGAL: 0.60, 95% CI 0.54-0.66, and 0.57, 95% CI 0.52-0.63; admission sCr: 0.60, 95% CI 0.54-0.64, and 0.59, 95% CI 0.53-0.64, at 30 and 60 days, respectively], peak sCr 0.61 [95% CI 0.55-0.67] and 0.59 [95% CI 0.54-0.64] at 30 and 60 days, respectively). NGAL was not predictive of the composite endpoint in multivariate analysis. CONCLUSIONS: Serum NGAL outperformed uNGAL but neither was superior to admission or peak sCr for predicting adverse events

    Antipsychotics, Metabolic Adverse Effects, and Cognitive Function in Schizophrenia

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    Cognitive impairment is a core symptom domain of schizophrenia. The effect of antipsychotics, the cornerstone of treatment in schizophrenia, on this domain is not fully clear. There is some evidence suggesting that antipsychotics may partially improve cognitive function, and that this improvement may vary depending on the specific cognitive domain. However, this research is confounded by various factors, such as age, duration/stage of illness, medication adherence, and extrapyramidal side effects that complicate the relationship between antipsychotics and cognitive improvement. Furthermore, antipsychotics—particularly the second generation, or “atypical” antipsychotics—can induce serious metabolic side effects, such as obesity, dyslipidemia and type 2 diabetes, illnesses which themselves have been linked to impairments in cognition. Thus, the inter-relationships between cognition and metabolic side effects are complex, and this review aims to examine them in the context of schizophrenia and antipsychotic treatment. The review also speculates on potential mechanisms underlying cognitive functioning and metabolic risk in schizophrenia. We conclude that the available literature examining the inter-section of antipsychotics, cognition, and metabolic effects in schizophrenia is sparse, but suggests a relationship between metabolic comorbidity and worse cognitive function in patients with schizophrenia. Further research is required to determine if there is a causal connection between the well-recognized metabolic adverse effects of antipsychotics and cognitive deficits over the course of the illness of schizophrenia, as well as, to determine underlying mechanisms. In addition, findings from this review highlight the importance of monitoring metabolic disturbances in parallel with cognition, as well as, the importance of interventions to minimize metabolic abnormalities for both physical and cognitive health
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