Signatures of Dissipation Driven Quantum Phase Transition in Rabi Model.

By using the worldline Monte Carlo technique, matrix product state, and a variational approach à la Feynman, we investigate the equilibrium properties and relaxation features of the dissipative quantum Rabi model, where a two level system is coupled to a linear harmonic oscillator embedded in a viscous fluid. We show that, in the Ohmic regime, a Beretzinski-Kosterlitz-Thouless quantum phase transition occurs by varying the coupling strength between the two level system and the oscillator. This is a nonperturbative result, occurring even for extremely low dissipation magnitude. By using state-of-the-art theoretical methods, we unveil the features of the relaxation towards the thermodynamic equilibrium, pointing out the signatures of quantum phase transition both in the time and frequency domains. We prove that, for low and moderate values of the dissipation, the quantum phase transition occurs in the deep strong coupling regime. We propose to realize this model by coupling a flux qubit and a damped LC oscillator.

P-glycoprotein inhibition with verapamil overcomes mometasone resistance in Chronic Sinusitis with Nasal Polyps.

BACKGROUND: P-glycoprotein (P-gp) is a membrane efflux pump which is overexpressed in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and promotes Type 2 inflammation. Glucocorticoids (GC) are substrates of P-gp suggesting that overexpression may additionally contribute to GC resistance in CRSwNP. This study aims to determine whether P-gp inhibition using verapamil enhances mometasone retention and efficacy in nasal polyp explants. METHODOLOGY: IRB approved study in which organotypic polyp explants were exposed to mometasone (4.15 µg/mL) and verapa- mil (125 µg/mL) as mono and combination therapy. The effect of verapamil on mometasone tissue retention over time was deter- mined using HPLC. The effect of verapamil on mometasone anti-inflammatory function was determined using ELISA for secreted IL-5. Groups were compared using Kruskal-Wallis test. RESULTS: P-gp expression strongly and significantly inversely correlated with mometasone retention 1hr after exposure, with a ne- arly 6-fold reduction in tissue retention between the lowest and highest P-gp expressing polyp explants. P-gp inhibition reversed this effect and significantly improved mometasone retention at 1hr relative to mometasone alone. The combination of mome- tasone and verapamil significantly reduced IL-5 secretion relative to vehicle control and outperformed either treatment alone. CONCLUSIONS: Our study confirms that P-gp contributes to mometasone resistance. This P-gp mediated resistance was successfully reversed by addition of the P-gp inhibitor verapamil. Verapamil further significantly enhanced the anti-inflammatory effect of mometasone when given as a combination therapy.

Kidney Intragraft Homing of De Novo Donor-Specific HLA Antibodies Is an Essential Step of Antibody-Mediated Damage but Not Per Se Predictive of Graft Loss.

Donor-specific HLA antibody (DSA)-mediated graft injury is the major cause of kidney loss. Among DSA characteristics, graft homing has been suggested as an indicator of severe tissue damage. We analyzed the role of de novo DSA (dnDSA) graft homing on kidney transplantation outcome. Graft biopsy specimens and parallel sera from 48 nonsensitized pediatric kidney recipients were analyzed. Serum samples and eluates from graft biopsy specimens were tested for the presence of dnDSAs with flow bead technology. Intragraft dnDSAs (gDSAs) were never detected in the absence of serum dnDSAs (sDSAs), whereas in the presence of sDSAs, gDSAs were demonstrated in 72% of biopsy specimens. A significantly higher homing capability was expressed by class II sDSAs endowed with high mean fluorescence intensity and C3d- and/or C1q-fixing properties. In patients with available sequential biopsy specimens, we detected gDSAs before the appearance of antibody-mediated rejection. In sDSA-positive patients, gDSA positivity did not allow stratification for antibody-mediated graft lesions and graft loss. However, a consistent detection of skewed unique DSA specificities was observed over time within the graft, likely responsible for the damage. Our results indicate that gDSAs could represent an instrumental tool to identify, among sDSAs, clinically relevant antibody specificities requiring monitoring and possibly guiding patient management.

Acquisition of C3d-Binding Activity by De Novo Donor-Specific HLA Antibodies Correlates With Graft Loss in Nonsensitized Pediatric Kidney Recipients.

Alloantibody-mediated graft injury is a major cause of kidney dysfunction and loss. The complement-binding ability of de novo donor-specific antibodies (dnDSAs) has been suggested as a prognostic tool to stratify patients for clinical risk. In this study, we analyzed posttransplant kinetics of complement-fixing dnDSAs and their role in antibody-mediated rejection development and graft loss. A total of 114 pediatric nonsensitized recipients of first kidney allograft were periodically monitored for dnDSAs using flow bead assays, followed by C3d and C1q assay in case of positivity. Overall, 39 patients developed dnDSAs, which were C1q(+) and C3d(+) in 25 and nine patients, respectively. At follow-up, progressive acquisition over time of dnDSA C1q and C3d binding ability, within the same antigenic specificity, was observed, paralleled by an increase in mean fluorescence intensity that correlated with clinical outcome. C3d-fixing dnDSAs were better fit to stratify graft loss risk when the different dnDSA categories were evaluated in combined models because the 10-year graft survival probability was lower in patients with C3d-binding dnDSA than in those without dnDSAs or with C1q(+) /C3d(-) or non-complement-binding dnDSAs (40% vs. 94%, 100%, and 100%, respectively). Based on the kinetics profile, we favor dnDSA removal or modulation at first confirmed positivity, with treatment intensification guided by dnDSA biological characteristics.

Transition to the Haldane phase driven by electron-electron correlations.

One of the most famous quantum systems with topological properties, the spin [Formula: see text] antiferromagnetic Heisenberg chain, is well-known to display exotic [Formula: see text] edge states. However, this spin model has not been analyzed from the more general perspective of strongly correlated systems varying the electron-electron interaction strength. Here, we report the investigation of the emergence of the Haldane edge in a system of interacting electrons - the two-orbital Hubbard model-with increasing repulsion strength U and Hund interaction JH. We show that interactions not only form the magnetic moments but also form a topologically nontrivial fermionic many-body ground-state with zero-energy edge states. Specifically, upon increasing the strength of the Hubbard repulsion and Hund exchange, we identify a sharp transition point separating topologically trivial and nontrivial ground-states. Surprisingly, such a behaviour appears already at rather small values of the interaction, in a regime where the magnetic moments are barely developed.

Phytoplanktonic community and bio-optical properties in coastal waters of an Argentinian Patagonian gulf.

The influence of the phytoplankton community in the light absorption budget was quantified in coastal waters of the North region of the San Jorge Gulf (Argentinian Patagonia). The phytoplanktonic composition and their absorption spectra were determined. Nanoflagellates and diatoms were the dominant groups. The toxigenic dinoflagellate Dinophysis acuminata was recorded in all the sampling sites. The optical characterization of the particulate material showed that 60 % of the absorption at 443 nm and 88 % of absorption at 675 nm was due to phytoplankton. The contributions of phytoplankton to total absorption at 443 nm wavelengths reached 50 %. The absorption by chromophoric dissolved organic matter (CDOM) and non-algal particles (NAP) was predominant in turbulent waters (>60 %). This study shows the influence of submesoscale physical-biological interactions in the light absorption budget. The field absorption spectra of active optical components are of interest in the assessment and development of regional ocean color satellite algorithms.

Trocar vs. Seldinger small bore pleural drains: does the technique influence the outcomes? A prospective single-centre study.

OBJECTIVE: The aim of this study is to compare two positioning techniques of 12-French (Fr) thoracic drains in terms of efficacy, safety, and patient comfort. PATIENTS AND METHODS: This is a prospective, non-randomized, competitive, non-inferiority study comparing the Seldinger vs. Trocar technique. The primary endpoint was an analysis of the factors that led to unsuccessful drainage positioning. Between the two groups, clinical variables, procedure times, pain, and complications were compared. RESULTS: Seventy-two patients were enrolled in group 1 (Seldinger) and 45 in group 2 (Trocar). The mean procedural time was 7.93±3.02 min vs. 7.09±3.67 min, respectively (p: 0.33). The mean VAS for procedural pain was 2.22±1.47 vs. 2.80±1.88, p: 0.07, and the mean at day 2 was 3.6±1.2 in the SBWGD group vs. 2.7±1.1 in the Unico Group (p: 0.04). There was no difference in terms of complications, residual effusion, and pneumothorax at the first post-procedural chest X-ray. Four days after the procedure, the drain removal rate was 11.6% in group 1 vs. 25% in group 2 p: 0.063). The chest tube was removed after a mean period of 8.87±7.20 days after resolution of pleural effusion or tube dislodgement (7 cases in group 1 vs. 11 in group 2, p: 0.053). CONCLUSIONS: The two techniques resulted in comparable pain and complication rates. Both drains are well-tolerated and efficient at draining pleural effusion, with very low rates of complications and failure. We recommend inserting a longer tube for patients who require chest drainage for an extended period of time.

Posttransplant de novo donor-specific hla antibodies identify pediatric kidney recipients at risk for late antibody-mediated rejection.

The emerging role of humoral immunity in the pathogenesis of chronic allograft damage has prompted research aimed at assessing the role of anti-HLA antibody (Ab) monitoring as a tool to predict allograft outcome. Data on the natural history of allografts in children developing de novo Ab after transplantation are limited. Utilizing sera collected pretransplant, and serially posttransplant, we retrospectively evaluated 82 consecutive primary pediatric kidney recipients, without pretransplant donor-specific antibodies (DSA), for de novo Ab occurrence, and compared results with clinical-pathologic data. At 4.3-year follow up, 19 patients (23%) developed de novo DSA whereas 24 had de novo non-DSA (NDSA, 29%). DSA appeared at a median time of 24 months after transplantation and were mostly directed to HLA-DQ antigens. Among the 82 patients, eight developed late/chronic active C4d+ antibody-mediated rejection (AMR), and four C4d-negative AMR. Late AMR correlated with DSA (p < 0.01), whose development preceded AMR by 1-year median time. Patients with DSA had a median serum creatinine of 1.44 mg/dL at follow up, significantly higher than NDSA and Ab-negative patients (p < 0.005). In our pediatric cohort, DSA identify patients at risk of renal dysfunction, AMR and graft loss; treatment started at Ab emergence might prevent AMR occurrence and/or progression to graft failure.

Quadrupolar magnetic excitations in an isotropic spin-1 antiferromagnet.

The microscopic origins of emergent behaviours in condensed matter systems are encoded in their excitations. In ordinary magnetic materials, single spin-flips give rise to collective dipolar magnetic excitations called magnons. Likewise, multiple spin-flips can give rise to multipolar magnetic excitations in magnetic materials with spin S ≥ 1. Unfortunately, since most experimental probes are governed by dipolar selection rules, collective multipolar excitations have generally remained elusive. For instance, only dipolar magnetic excitations have been observed in isotropic S = 1 Haldane spin systems. Here, we unveil a hidden quadrupolar constituent of the spin dynamics in antiferromagnetic S = 1 Haldane chain material Y2BaNiO5 using Ni L3-edge resonant inelastic x-ray scattering. Our results demonstrate that pure quadrupolar magnetic excitations can be probed without direct interactions with dipolar excitations or anisotropic perturbations. Originating from on-site double spin-flip processes, the quadrupolar magnetic excitations in Y2BaNiO5 show a remarkable dual nature of collective dispersion. While one component propagates as non-interacting entities, the other behaves as a bound quadrupolar magnetic wave. This result highlights the rich and largely unexplored physics of higher-order magnetic excitations.

Regulatory functions of insulin-like growth factor binding proteins in osteoarthritis.

Insulin-like growth factor binding proteins (IGFBPs) are a group of secreted proteins, which bind to IGF-I (and IGF-II) with high affinity and modulate the biological actions of IGFs. Abundant evidence points the importance of the IGF-I/IGFBP system on both cell growth and differentiation. A role for the IGF-I/IGFBP system in the regulation of normal human cartilage has been previously reported. In this context, recent studies suggest an emerging role for IGFBPs in the failure of cartilage during osteoarthritis (OA). Indeed, increased IGFBP levels have been reported in both the articular cartilage and synovial fluid from patients with OA. Overexpression of IGFBPs, by altering the bioavailability and function of IGFs, is likely to deliver IGFs-independent signals for chondrocyte survival. This, at least in part, might explain the degenerative changes of the cartilage in OA. Further studies are necessary to clarify the mechanisms that cause the overexpression of IGFBPs in patients with OA. Advances in our understanding of the relationship between osteoarthritis and the IGF-I/IGFBP system may lead to new treatment strategies for this degenerative disease.

Sirolimus therapy in liver transplant patients: an initial experience at a single center.

Sirolimus (SRL) is an mTOR inhibitor that has been shown, in contrast to calcineurin inhibitors (CNI), to inhibit cancers in experimental models. Since February 2005, we introduced SRL in liver transplant patients in group a, in whom the primary disease was hepatocellular carcinoma (HCC) associated with hepatitis B virus (HBV), hepatitis C virus (HCV), alcoholic or autoimmune liver cirrhosis, and group b, HCC-negative patients who developed posttransplantation cancers de novo. Of 18 patients in group a, 11 received SRL ab initio (subgroup a1), starting for 10 patients at 66.1+/-29.2 days after surgical healing and after 10 days in 1 case; the remaining 7 patients (subgroup a2) received SRL at 31.2+/-24.2 months. Three patients in group b, included 1 with Kaposi's sarcoma, 1 with bladder cancer, and 1 with thyroid cancer. In this group, SRL was introduced at 80.8+/-40.4 months. In all patients but one, who received a single 5 mg loading dose, SRL was started at 2 mg/d and adjusted to 6 to 8 ng/mL blood levels. CNI drugs, present as primary therapy, were gradually tapered to low levels and eventually stopped. The following observations were drawn from this initial experience: (1) 4/21 (19.0%) patients had to discontinue SRL because of early and late side effects: thrombocytopenia (n=2) and headache with leukopenia and leg edema associated with knee joint arthralgia (n=2); (2) 14 patients (11 in group a and 3 in group b) are still on SRL monotherapy; (3) 1 HCC recurrence and 1 de novo pancreatic adenocarcinoma were observed at 14 and 16 months, respectively (at the time of transplantation, both patients were beyond the MIlan HCC criteria), and (4) 1 patient, from subgroup a1, died after 99 days due to pneumonitis and possible relation to SRL lung toxicity. In conclusion, SRL appeared to be an effective immunosuppressant that could be used as monotherapy in liver transplant patients. Any conclusion on SRL anticancer effects can only come from randomized large studies after long follow-up.

Spin dynamics of the block orbital-selective Mott phase.

Iron-based superconductors display a variety of magnetic phases originating in the competition between electronic, orbital, and spin degrees of freedom. Previous theoretical investigations of the multi-orbital Hubbard model in one-dimension revealed the existence of an orbital-selective Mott phase (OSMP) with block spin order. Recent inelastic neutron scattering (INS) experiments on the BaFe2Se3 ladder compound confirmed the relevance of the block-OSMP. Moreover, the powder INS spectrum revealed an unexpected structure, containing both low-energy acoustic and high-energy optical modes. Here we present the theoretical prediction for the dynamical spin structure factor within a block-OSMP regime using the density-matrix renormalization-group method. In agreement with experiments, we find two dominant features: low-energy dispersive and high-energy dispersionless modes. We argue that the former represents the spin-wave-like dynamics of the block ferromagnetic islands, while the latter is attributed to a novel type of local on-site spin excitations controlled by the Hund coupling.

Computing Resonant Inelastic X-Ray Scattering Spectra Using The Density Matrix Renormalization Group Method.

We present a method for computing the resonant inelastic x-ray scattering (RIXS) spectra in one-dimensional systems using the density matrix renormalization group (DMRG) method. By using DMRG to address this problem, we shift the computational bottleneck from the memory requirements associated with exact diagonalization (ED) calculations to the computational time associated with the DMRG algorithm. This approach is then used to obtain RIXS spectra on cluster sizes well beyond state-of-the-art ED techniques. Using this new procedure, we compute the low-energy magnetic excitations observed in Cu L-edge RIXS for the challenging corner shared CuO4 chains, both for large multi-orbital clusters and downfolded t-J chains. We are able to directly compare results obtained from both models defined in clusters with identical momentum resolution. In the strong coupling limit, we find that the downfolded t-J model captures the main features of the magnetic excitations probed by RIXS only after a uniform scaling of the spectra is made.

Medical report type in liver transplantation as a quality system document: new prospects for computerization.

The usage of a computerized system to organize data and ease the activity procedures of liver transplantation is useful in clinical transplantation. Preliminary cognitive research on systems of clinical transplantation database concerning medical reports was performed to verify their development level. The survey highlighted that, so far, there has been no experimentation that can be applied to a medical report type devoted to liver transplantation. Regulations in force substantially point out that the medical report ought to contain all items that have to be taken into account in handling the patient from pretransplantation to follow-up. The Department of Transplantation of Genoa chose its medical report model for liver transplantation. The medical report model included the following items: personal data; case history; diagnosis; initial examination for prelisting; fitness for transplantation; assistance context; clinical data including subjective, objective, and instrumental parameters; pharmacological therapies; informed consent, evaluation of fitness; nursing data; counseling and clinical evaluations according to protocols and guidelines of the national transplantation centers. If the computing is well trained, it is supposed to help maintain a whole data view provided it is supplied information in an adequate way. Immediate clinical procedural advantages and useful scientific observations may be obtained from a high-quality database. In fact, all functions have to be applied to specific clinical, administrative needs to be remotely shared and conveniently integrated with each other to make the liver transplantation medical report an easy and handy instrument for inputting and handling data. It must be a precise, complete instrument that may be accessible in real time from any site connected with the intranet network, be unchangeable, and be protected to ensure certification and forensic medicine value.

Phytohemagglutinin or pokeweed mitogen induction of in vitro colony formation by T-cells from patients with chronic lymphocytic leukemia.

The colony-forming capacity of peripheral blood T-cells isolated from B-cell chronic lymphocytic leukemia patients was studied and compared with that of peripheral blood T-cells isolated from 2 groups of normal controls (young and aged healthy donors). Upon stimulation with phytohemagglutinin or pokeweed mitogen. T-cells from both the patients and the controls developed into colonies but only in the presence of the appropriate conditioned media. When the responses of the 3 groups were compared, no statistically significant differences were detected. However, the number of patients who failed to respond to phytohemagglutinin was larger than that of normal controls. Studies on a selected group of patients demonstrated that such unresponsiveness was unrelated to the presence of suppressor cells or to inadequate conditions used for stimulation in culture. Rather, this unresponsiveness may be connected with an intrinsic T-cell defect present in certain B-cell chronic lymphocytic leukemia patients.

Spectral functions with the density matrix renormalization group: Krylov-space approach for correction vectors.

Frequency-dependent correlations, such as the spectral function and the dynamical structure factor, help illustrate condensed matter experiments. Within the density matrix renormalization group (DMRG) framework, an accurate method for calculating spectral functions directly in frequency is the correction-vector method. The correction vector can be computed by solving a linear equation or by minimizing a functional. This paper proposes an alternative to calculate the correction vector: to use the Krylov-space approach. This paper then studies the accuracy and performance of the Krylov-space approach, when applied to the Heisenberg, the t-J, and the Hubbard models. The cases studied indicate that the Krylov-space approach can be more accurate and efficient than the conjugate gradient, and that the error of the former integrates best when a Krylov-space decomposition is also used for ground state DMRG.

Cytotoxic molecule mRNA expression in chronically rejected human kidney allografts.

The pathogenesis of immunological and nonimmunological components that cause chronic kidney allograft nephropathy (CAN), is not yet completely understood. To explore the possible contribution of alloreactive cytotoxic T cells, we analyzed the transcription of cytotoxic molecules such as granzyme B and perforin using semiquantitative RT-PCR on surgically removed grafts obtained from two groups: group 1 (n = 10) were cases of CAN; group 2 (n = 3) had no CAN. Among group 1 kidneys, granzyme-B was expressed in 7 of 10, whereas perforin was detectable in 9 of 10 cases; their detection was not related to the presence of superimposed signs of acute graft lesions. Cytotoxic molecules were never found in group 2 kidneys. These results show that explanted chronically rejected grafts display cytotoxic molecule transcripts in addition to Th2 type cytokines, such as IL-10, IL-3, and IL-6, suggesting that both cellular and humoral alloreactive mechanisms may play important roles in CAN pathogenesis.

[Renal transplantation in the North Italy Transplant program (NITp): Organ allocation and results]. / Il trapianto renale nel Nord Italia Transplant program (NITp): assegnazione degli organi e risultati.

Renal transplantation is an effective therapeutic tool for patients with end-stage renal diseases (ESRDs). Data reported in this article summarize the results obtained from 30 years' activity in the North Italy Transplant program (NITp), the first transplant organization in Italy that implemented a donor procurement and organ transplantation network. In the NITp kidney allocation is governed by a computerized algorithm, NITK3, put in place in 1997, aimed at ensuring equity, transparency and traceability during the stages of the allocation decision-making process. The NITp working group has recognized the NITK3 criteria and they are periodically reviewed following the results of the analysis of patients' transplantation odds. The results obtained with the use of the NITK3 algorithm have been very satisfactory: after 6 yrs, a significantly higher percentage of patients at immunological risk (sensitized or waiting for re-transplant), of patients waiting for >3 yrs and of patients with 0-1 HLA A,B,DR mismatches have been transplanted. Moreover, a higher percentage of kidneys were used locally (in a hospital within the procurement area), and this is known to stimulate donor procurement. Finally, we performed a preliminary statistical analysis of transplants carried out from 1998-2002 in 5/16 centers of the NITp area, demonstrating the quality of the NITp program in terms of patient and graft survival, and that donor and recipient age are the variables significantly impacting on transplant results.

PHA-induced human T cell colony formation: enhancing effect of large granular lymphocytes.

The capacity of phytohemagglutinin (PHA)-stimulated human T cells to develop into colonies in agar has been evaluated in the presence or absence of a variety of peripheral blood mononuclear cell subsets. A subpopulation of non-T, non-B cells with receptors for the Fc portion of IgG (i.e. third population cells or TPC) was found to enhance considerably the T cell colony forming capacity. Since TPC have been previously shown to be highly enriched for large granular lymphocytes (LGL, i.e. cells with cytoplasmic azurophilic granules and acid hydrolases), LGL were purified on Percoll density gradients and tested for their T cell colony enhancing capacity. It was shown that LGL were indeed the cells capable of enhancing the T cell colony formation.

De novo cancers in paediatric renal transplant recipients: a multicentre analysis within the North Italy Transplant programme (NITp), Italy.

The purpose of this study was to determine the frequency and the outcome of de novo malignancies in a cohort of renal transplant paediatric patients. The records of 493 kidney transplants, carried out in 454 paediatric recipients at the three paediatric transplant centres of the North Italy Transplant programme (NITp, Italy) were reviewed. 10 cases of malignancies (2.2%) comprising both PTLD (post-transplant lymphoproliferative disorders) (6 cases, 1.3%) and non-PTLD malignancies (4 cases, 0.88%) were reported. Non-PTLD included one urothelial carcinoma and one Wilms' tumour of the recipient's left native kidney, one abdominal dysgerminoma and one optic nerve glioma of the left eye. The PTLD consisted of localised or disseminated Epstein-Barr virus (EBV)--associated B-lymphocyte monoclonal (5 cases) and polyclonal (1 case) proliferations. All patients suffering from PTLD had been EBV-negative at the time of transplantation, but developed EBV primary infection after transplantation. All PTLD patient donors were EBV-positive. In addition, all but 1 patient received, before and/or after transplantation, a range of immunosuppressive drugs in addition to the baseline prophylactic immunosuppressive regimen. Moreover, 3 patients suffered from syndromes associated with a genetic predisposition to cancer. Finally, the malignancies reported here were associated with 20% graft failure and 20% mortality rates.