59 research outputs found
Spin dynamics in hole-doped two-dimensional S=1/2 Heisenberg antiferromagnets: ^{63}Cu NQR relaxation in La_{2-x}Sr_xCuO_4 for
The effects on the correlated Cu^{2+} S = 1/2 spin dynamics in the
paramagnetic phase of La_{2-x}Sr_xCuO_4 (for ) due to the
injection of holes are studied by means of ^{63}Cu NQR spin-lattice relaxation
time T_1 measurements. The results are discussed in the framework of the
connection between T_1 and the in-plane magnetic correlation length
. It is found that at high temperatures the system remains in
the renormalized classical regime, with a spin stiffness constant
reduced by small doping to an extent larger than the one due to Zn doping. For
the effect of doping on appears to level off. The
values for derived from T_1 for K are much larger
than the ones estimated from the temperature behavior of sublattice
magnetization in the ordered phase (). It is argued that these
features are consistent with the hypothesis of formation of stripes of
microsegregated holes.Comment: 10 pages, 3 figure
Magnetization profiles and NMR spectra of doped Haldane chains at finite temperatures
Open segments of S=1 antiferromagnetic spin chains are studied at finite
temperatures and fields using continuous time Quantum Monte Carlo techniques.
By calculating the resulting magnetization profiles for a large range of chain
lengths with fixed field and temperature we reconstruct the experimentally
measured NMR spectrum of impurity doped YBaNiMgO. For
temperatures above the gap the calculated NMR spectra are in excellent
agreement with the experimental results, confirming the existence of
excitations at the end of open S=1 chain segments. At temperatures below the
gap, neglecting inter chain couplings, we still find well defined peaks in the
calculated NMR spectra corresponding to the chain end excitations. At
low temperatures, inter chain couplings could be important, resulting in a more
complicated phase.Comment: 7 pages, 5 figures, minor correction
The circadian rhythm of biochemical makers of bone resorption is normally synchronized in breast cancer patients with bone metastases indipendently of tumor load
Spin-1/2 Kagome Like Lattice in Volborthite Cu3V2O7(OH)2-H2O
A novel cuprate Volborthite, Cu3V2O7(OH)2-2H2O, containing an S-1/2 (Cu 2+
spin) kagome-like lattice is studied by magnetic susceptibility, specific heat,
and 51 V NMR measurements. Signs for neither long-range order nor spin-gapped
singlet ground states are detected down to 1.8 K, in spite of large
antiferromagnetic couplings of ~100 K between Cu spins forming a
two-dimensional kagome-like network. It is suggested that Volborthite
represents a system close to a quantum critical point between classical
long-range ordered and quantum disordered phases.Comment: 9 pages, 8 figures, J. Phys. Soc. Jpn, in pres
Changes of bone turnover markers and serum PTH after night or morning administration of zoledronic acid in breast cancer patients with bone metastases
Persistent circadian rhythm of bone turnover in bone metastatic breast cancer suggests greater skeletal retention of bisphosphonates if administered in the night. We assessed differential effects of night vs morning administration of zoledronic acid (ZA) on bone turnover. Forty-four breast cancer patients with bone metastases were randomised to receive intravenous ZA (4 mg) at 1100 or 2300 hours every 28 days for four times. Urinary concentration N-telopeptide of type-I collagen (NTX) and deoxypyridinolines, and serum C-telopeptide of type-I collagen (CTX), bone alkaline phosphatase (ALP), osteocalcin and Parathyroid hormone (PTH) was measured in the morning at baseline and after 4, 7, 14, 28, 56 and 84 days. Urinary ZA concentration was also measured. Zoledronic acid caused significant decreases of NTX and CTX (P<0.001), without any difference in percent changes between night and morning arms. Bone ALP and osteocalcin were also significantly affected by ZA (P=0.001), without any difference between arms. Parathyroid hormone significantly increased in both the arms; PTH increase was lower in the night arm (P=0.001). From the second administration onwards, urinary ZA level was significantly higher in the night arm (P<0.01). Administration of ZA at two opposite phases of the circadian cycle causes similar changes of bone-turnover marker levels, but has differential effects on the level of serum PTH
Expression of two markers of germinal center T cells (SAP and PD-1) in angioimmunoblastic T-cell lymphoma
How do cardiologists select patients for dual antiplatelet therapy continuation beyond 1 year after a myocardial infarction? Insights from the EYESHOT Post-MI Study
Background: Current guidelines suggest to consider dual antiplatelet therapy (DAPT) continuation for longer than 12 months in selected patients with myocardial infarction (MI). Hypothesis: We sought to assess the criteria used by cardiologists in daily practice to select patients with a history of MI eligible for DAPT continuation beyond 1 year. Methods: We analyzed data from the EYESHOT Post-MI, a prospective, observational, nationwide study aimed to evaluate the management of patients presenting to cardiologists 1 to 3 years from the last MI event. Results: Out of the 1633 post-MI patients enrolled in the study between March and December 2017, 557 (34.1%) were on DAPT at the time of enrolment, and 450 (27.6%) were prescribed DAPT after cardiologist assessment. At multivariate analyses, a percutaneous coronary intervention (PCI) with multiple stents and the presence of peripheral artery disease (PAD) resulted as independent predictors of DAPT continuation, while atrial fibrillation was the only independent predictor of DAPT interruption for patients both at the second and the third year from MI at enrolment and the time of discharge/end of the visit. Conclusions: Risk scores recommended by current guidelines for guiding decisions on DAPT duration are underused and misused in clinical practice. A PCI with multiple stents and a history of PAD resulted as the clinical variables more frequently associated with DAPT continuation beyond 1 year from the index MI
Magnetization and dimerization profiles of the cut two-leg spin ladder and spin-1 chain
The physical properties of the edge states of the cut two-leg spin ladder are
investigated by means of the bosonization approach. By carefully treating
boundary conditions, we derive the existence of spin-1/2 edge states in the
spin ladder with a ferromagnetic rung exchange and for the open spin-1
Heisenberg chain. In contrast, such states are absent in the antiferromagnetic
rung coupling case. The approach, based on a mapping onto decoupled
semi-infinite off-critical Ising models, allows us to compute several physical
quantities of interest. In particular, we determine the magnetization and
dimerization profiles of the cut two-leg spin ladder and of the open
biquadratic spin-1 chain in the vicinity of the SU(2) WZNW critical point.Comment: RevTeX 4, no figure, 26 page
Monitoring the quality of laboraties and the prevalence of resistance to antituberculosis drugs: Italy, 1998-2000
In 1998 a network of 20 regional tuberculosis (TB) laboratories (the Italian Multicentre Study on Resistance to Antituberculosis drugs (SMIRA) network) was established in Italy to implement proficiency testing and to monitor the prevalence of drug resistance nationwide. The network managed 30% of all TB cases reported in Italy each year. The aim of the present report is to describe: 1) the accuracy of drug-susceptibility testing in the network; 2) the prevalence of drug resistance for the period 1998-2000. Data were collected from the network laboratories. Sensitivity to streptomycin and ethambutol increased from the first survey (1998-1999) to the second survey (2000) from 87.7 to 91.9%. Specificity, predictive values for resistance and susceptibility, efficiency and reproducibility were consistent in both surveys. In previously untreated cases, the prevalence of multidrug-resistance was the same in both surveys (1.2%), while a slight decrease from the first to the second survey was observed for monoresistance to rifampicin (from 0.8 to 0.4%) and isoniazid (from 2.9 to 2%,). The significant association found between isoniazid resistance and immigration is a useful indicator for both clinicians managing individual tuberculosis cases and public health services planning control strategies
Data for: “Evaluation of contaminant retention in the soil of Sustainable Drainage Systems: methodological reflections on the determination of sorption isotherms”
The reported data have been acquired within a research project investigating the ability of infiltration-based Sustainable Drainage Systems to mitigate pollutant fluxes in stormwater runoff. Sorption experiments have been carried out in batch systems, in order to characterize the sorption behavior of three soils towards copper and zinc, and one soil towards four organic micropollutants: Bisphenol A (BPA), 4-tert-Octylphenol (OP), 4-Nonylphenol (4NP), and Nonylphenol Ethoxylate (NP10). The soil samples originate from three source-control infiltration facilities.
• Soil 1 is a sandy loam from a roadside swale;
• Soil 2 is a silt loam from a roadside filter strip;
• Soil 3 is a sandy clay loam from an infiltration basin.
All experiments were carried out in non-competitive systems (i.e., individual contaminants in each batch system). The “reference conditions” corresponded to an electrolyte solution which mimicked the composition of runoff water (Evian and ultrapure water, volumetric ratio of 1:10). The sorption behavior of metals onto soils 1 and 3 was also investigated in different conditions:
• 1.0 g/L of sodium chloride, to investigate the effects of deicing salt in runoff water;
• 10 mg/L of humic acids, to represent the natural generation of dissolved organic matter in the soil solution.
The methodology used to select the experimental conditions is thoroughly described in a research article entitled: “Evaluation of contaminant retention in the soil of Sustainable Drainage Systems: methodological reflections on the determination of sorption isotherms” (Blue-Green Systems 1(1), doi: 10.2166/bgs.2019.196).
The appended files present the experimental points of the sorption isotherms for each characterized soil.
• Soil 1: metals in the reference conditions (Metals_ref), metals with sodium chloride (Metals_NaCl), metals with humic acids (Metals_HA), organic micropollutants;
• Soil 2: metals in the reference conditions;
• Soil 3: metals in the reference conditions, metals with sodium chloride, metals with humic acids.
The concentrations in the dissolved phase are referred to as “X_diss”, where X is the studied species (Cu, Zn, etc.), and are expressed in mg/L. BPA stands for Bisphenol A, OP stands for 4-tert-Octylphenol, 4NP stands for 4-Nonylphenol, and NP10 stands for Nonylphenol Ethoxylate. The contents in the solid phase are referred to as “X_sorb” and are expressed in mg/kg.
In case the tests were carried out in duplicates, the columns “X_diss” and “X_sorb” correspond to the mean values of the experiments; two additional columns, referred to as “sdX_diss” and “sdX_sorb”, provide the standard deviations (also expressed in mg/L and mg/kg, respectively)
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