Dynamical Solitons and Boson Fractionalization in Cold-Atom Topological Insulators.

We study the Z_{2} Bose-Hubbard model, a chain of interacting bosons the tunneling of which is dressed by a dynamical Z_{2} field. The interplay between spontaneous symmetry breaking (SSB) and topological symmetry protection gives rise to interesting fractional topological phenomena when the system is doped to certain incommensurate fillings. In particular, we hereby show how topological defects in the Z_{2} field can appear in the ground state, connecting different SSB sectors. These defects are dynamical and can travel through the lattice carrying both a topological charge and a fractional particle number. In the hardcore limit, this phenomenon can be understood through a bulk-defect correspondence. Using a pumping argument, we show that it survives also for finite interactions, demonstrating how boson fractionalization induced by topological defects can occur in strongly correlated bosonic systems. Our results indicate the possibility of observing this phenomenon, which appears for fermionic matter in solid-state and high-energy physics, using ultracold atomic systems.

Experience with anidulafungin in patients with allogeneic hematopoietic stem cell transplantation and graft-versus-host disease.

BACKGROUND: It is well known that both acute and chronic graft-versus-host disease (GVHD) are associated with invasive fungal disease (IFD). Because the galactomannan antigen diagnostic test has low specificity and sensitivity outside of the neutropenic period, many institutions use posaconazole or voriconazole for IFD prophylaxis during GVHD treatment. Moreover, several factors, mainly hepatic impairment, can limit the use of extended spectrum azoles, both in prophylaxis or treatment. METHODS: We retrospectively analyzed 25 patients with allogeneic hematopoietic stem cell transplantation (HSCT) and GVHD - grade III-IV acute GHVD (n = 15), progressive chronic GVHD (n = 7), and "overlap" GVHD (n = 3) - who received intravenous anidulafungin (200 mg on day 1, followed by 100 mg once daily). If necessary, anidulafungin treatment was followed by oral administration of 200 mg voriconazole twice a day or 200 mg posaconazole 3 times daily until patients were considered not at risk for IFD. RESULTS: Twenty-one patients (85%) received anidulafungin as prophylaxis and 5 patients (15%) received it as treatment. Median duration of intravenous anidulafungin administration was 8 days (range 6-17). Seven patients (28%) presented mild adverse effects, with no significant interactions with calcineurin inhibitors. Sequentially, 4 patients received voriconazole and 6 posaconazole. Two patients (8%) developed IFD after anidulafungin withdrawal: 1 with Candida albicans and the other with Mucor, 8 and 5 days after withdrawal, respectively. CONCLUSIONS: Our results are of interest owing to the absence of data in the literature on anidulafungin use in HSCT patients with GVHD, and suggest that anidulafungin, because of its spectrum, pharmacological profile, low toxicity, and absence of interactions with immunosuppressants, could be a drug of choice in this setting.

Dissipation-assisted quantum information processing with trapped ions.

We introduce a scheme to perform dissipation-assisted quantum information processing in ion traps considering realistic decoherence rates, for example, due to motional heating. By means of continuous sympathetic cooling, we overcome the trap heating by showing that the damped vibrational excitations can still be exploited to mediate coherent interactions as well as collective dissipative effects. We describe how to control their relative strength experimentally, allowing for protocols of coherent or dissipative generation of entanglement. This scheme can be scaled to larger ion registers for coherent or dissipative many-body quantum simulations.

Controlling and measuring quantum transport of heat in trapped-ion crystals.

Measuring heat flow through nanoscale devices poses formidable practical difficulties as there is no "ampere meter" for heat. We propose to overcome this problem in a chain of trapped ions, where laser cooling the chain edges to different temperatures induces a heat current of local vibrations (vibrons). We show how to efficiently control and measure this current, including fluctuations, by coupling vibrons to internal ion states. This demonstrates that ion crystals provide an ideal platform for studying quantum transport, e.g., through thermal analogues of quantum wires and quantum dots. Notably, ion crystals may give access to measurements of the elusive bosonic fluctuations in heat currents and the onset of Fourier's law. Our results are strongly supported by numerical simulations for a realistic implementation with specific ions and system parameters.

Lieb-Robinson bounds for spin-boson lattice models and trapped ions.

We derive a Lieb-Robinson bound for the propagation of spin correlations in a model of spins interacting through a bosonic lattice field, which satisfies a Lieb-Robinson bound in the absence of spin-boson couplings. We apply these bounds to a system of trapped ions and find that the propagation of spin correlations, as mediated by the phonons of the ion crystal, can be faster than the regimes currently explored in experiments. We propose a scheme to test the bounds by measuring retarded correlation functions via the crystal fluorescence.

In vitro and in vivo efficacy of a hydrated sodium calcium aluminosilicate to bind and reduce aflatoxin residues in tissues of broiler chicks fed aflatoxin B1.

The aim of this study was to determine the binding capacity of a hydrated sodium calcium aluminosilicate (HSCAS) for aflatoxin B(1) (AFB(1)), and the efficacy of the HSCAS to reduce the concentrations of residual AFB(1) and its metabolites in the liver and kidney of broilers fed AFB(1). One hundred 1-d-old male broilers (Ross 708) were maintained in chick batteries and allowed ad libitum access to feed and water. A completely randomized design was used with 5 replicate pens of 5 chicks assigned to each of 4 dietary treatments from hatch to 21 d. Dietary treatments included the following: A) basal diet (BD), with no HSCAS or AFB(1), B) BD supplemented with 0.5% HSCAS only, C) BD supplemented with 2.5 mg of AFB(1)/kg of feed, and D) BD supplemented with 2.5 mg of AFB(1)/kg of feed and 0.5% HSCAS. On d 21, 5 chicks from each treatment were anesthetized with carbon dioxide, killed by cervical dislocation, and samples of liver and kidney were collected for analysis of AFB(1) residues. The percentage of AFB(1) bound for each concentration of adsorbent (100, 10, 1, 0.5, 0.25, and 0.05 mg/10 mL) was 100, 91.1, 81.8, 75.4, 40.1, and 8.8%, respectively. Concentrations of aflatoxin residues (AFB(1), aflatoxicol, aflatoxins B(2) and G(1)) were lower (P < 0.05) in livers and kidneys of birds fed AFB(1) plus HSCAS (diet D), when compared with birds fed AFB(1) alone (diet C). However, histopathology data from the in vivo study indicated that HSCAS did not prevent lesions associated with aflatoxicosis. The decrease in the bioavailability of AFB(1) caused by the HSCAS reduced aflatoxin residues in liver and kidney, but not enough to completely prevent the toxic effects of AFB(1) in broilers.

Spin Peierls quantum phase transitions in Coulomb crystals.

The spin Peierls instability describes a structural transition of a crystal due to strong magnetic interactions. Here, we demonstrate that cold Coulomb crystals of trapped ions provide an experimental test bed in which to study this complex many-body problem and to access extreme regimes where the instability is triggered by quantum fluctuations alone. We present a consistent analysis based on different analytical and numerical methods, and we provide a detailed discussion of its experimental feasibility.

Effects of melamine in young broiler chicks.

A study was conducted to determine the toxicity of melamine in young broilers fed graded levels of melamine. An additional objective was to determine melamine residual levels in selected tissues. One hundred and seventy-five 1-d-old male Ross broiler chicks were sorted to a randomized block design in stainless steel battery pens. Chicks were assigned to 7 dietary treatments containing 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% melamine. Each dietary treatment was fed to 5 replicate pens of 5 chicks for 21 d. Mortality increased quadratically (P<0.001) with increasing dietary concentrations of melamine. However, compared with controls, mortality was only higher (P<0.001) in birds fed≥2.5% melamine. Feed intake decreased linearly (P<0.001), whereas BW gain decreased quadratically (P<0.02) with increasing dietary concentrations of melamine. Compared with controls, both feed intake and BW gain were lower (P<0.001) only in birds fed≥1.0% melamine. Relative kidney weights increased linearly (P<0.001), whereas relative liver weights increased quadratically (P<0.05) with increasing dietary concentrations of melamine. Melamine residues in breast muscle and liver tissue increased linearly (P<0.001) with increasing dietary concentrations of melamine, whereas melamine residues in kidney and bile increased quadratically (P<0.02) with increasing dietary concentrations of melamine. Compared with controls, melamine concentrations in liver and kidney were higher (P<0.001) in birds fed all levels of melamine, whereas melamine concentrations in breast muscle and bile were only higher (P<0.001) in birds fed≥1.0% melamine. Serum albumin, total protein, globulin, and calcium increased quadratically (P<0.02) in birds as dietary melamine increased, whereas serum aspartate transaminase and gamma gluatamyltransferase increased linearly (P<0.01) with increasing levels of melamine in the diet. Renal histopathology revealed nonpolarizable melamine crystals in the collecting tubules and ducts of birds fed≥1.5% melamine. In summary, dietary melamine was toxic to broilers at concentrations≥1.0%.

Electron-mediated nuclear-spin interactions between distant nitrogen-vacancy centers.

We propose a scheme enabling controlled quantum coherent interactions between separated nitrogen-vacancy centers in diamond in the presence of strong magnetic fluctuations. The proposed scheme couples nuclear qubits employing the magnetic dipole-dipole interaction between the electron spins and, crucially, benefits from the suppression of the effect of environmental magnetic field fluctuations thanks to a strong microwave driving. This scheme provides a basic building block for a full-scale quantum-information processor or quantum simulator based on solid-state technology.

Frustrated quantum spin models with cold Coulomb crystals.

We exploit the geometry of a zigzag cold-ion crystal in a linear trap to propose the quantum simulation of a paradigmatic model of long-ranged magnetic frustration. Such a quantum simulation would clarify the complex features of a rich phase diagram that presents ferromagnetic, dimerized-antiferromagnetic, paramagnetic, and floating phases, together with previously unnoticed features that are hard to assess by numerics. We analyze in detail its experimental feasibility, and provide supporting numerical evidence on the basis of realistic parameters in current ion-trap technology.

KRAS p.G12C mutation occurs in 1% of EGFR-mutated advanced non-small-cell lung cancer patients progressing on a first-line treatment with a tyrosine kinase inhibitor.

BACKGROUND: KRAS is mutated in ∼30% of non-small-cell lung cancer (NSCLC) but it has also been identified as one of the mechanisms underlying resistance to tyrosine kinase inhibitors (TKIs) in EGFR-positive NSCLC patients. Novel KRAS inhibitors targeting KRAS p.G12C mutation have been developed recently with promising results. The proportion of EGFR-positive NSCLC tumours harbouring the KRAS p.G12C mutation upon disease progression is completely unexplored. MATERIALS AND METHODS: Plasma samples from 512 EGFR-positive advanced NSCLC patients progressing on a first first-line treatment with a TKI were collected. The presence of KRAS p.G12C mutation was assessed by digital PCR. RESULTS: Overall, KRAS p.G12C mutation was detected in 1.17% of the samples (n = 6). In two of these cases, we could confirm that the KRAS p.G12C mutation was not present in the pre-treatment plasma samples, supporting its role as an acquired resistance mutation. According to our data, KRASG12C patients showed similar clinicopathological characteristics to those of the rest of the study cohort and no statistically significant associations between any clinical features and the presence of the mutation were found. However, two out of six KRASG12C tumours harboured less common EGFR driver mutations (p.G719X/p.L861Q). All KRASG12C patients tested negative for the presence of p.T790M resistance mutation. CONCLUSIONS: The KRAS p.G12C mutation is detected in 1% of EGFR-positive NSCLC patients who progress on a first line with a TKI. All KRASG12C patients were negative for the presence of the p.T790M mutation and they did not show any distinctive clinical feature.

Wilson fermions and axion electrodynamics in optical lattices.

We show that ultracold Fermi gases in optical superlattices can be used as quantum simulators of relativistic lattice fermions in 3+1 dimensions. By exploiting laser-assisted tunneling, we find an analogue of the so-called naive Dirac fermions, and thus provide a realization of the fermion doubling problem. Moreover, we show how to implement Wilson fermions, and discuss how their mass can be inverted by tuning the laser intensities. In this regime, our atomic gas corresponds to a phase of matter where Maxwell electrodynamics is replaced by axion electrodynamics: a 3D topological insulator.

Realistic time-reversal invariant topological insulators with neutral atoms.

We lay out an experiment to realize time-reversal invariant topological insulators in alkali atomic gases. We introduce an original method to synthesize a gauge field in the near field of an atom chip, which effectively mimics the effects of spin-orbit coupling and produces quantum spin-Hall states. We also propose a feasible scheme to engineer sharp boundaries where the hallmark edge states are localized. Our multiband system has a large parameter space exhibiting a variety of quantum phase transitions between topological and normal insulating phases. Because of their remarkable versatility, cold-atom systems are ideally suited to realize topological states of matter and drive the development of topological quantum computing.

Anti-Inflammatory Local Effect of Hydroxytyrosol Combined with Pectin-Alginate and Olive Oil on Trinitrobenzene Sulfonic Acid-Induced Colitis in Wistar Rats.

Purpose: Evaluate the efficacy of hydroxytyrosol in the local treatment of inflammatory colitis. Currently, the existing treatments for inflammatory bowel diseases does not cure the disease and it is associated with high rates of side effects and complications. Hydroxytyrosol is a phenyl-ethyl-alcohol derived from the hydrolysis of oleuropein and present in olive oil, previous studies have demonstrated the anti-inflammatory effect of dietary hydroxytyrosol supplement, with no toxicity. Materials & Methods: Colitis has been induced by using Trinitrobenzene Sulfonic Acid at 40 rats. They were divided into four groups randomly: 10 rats without treatment; 10 rats with pectin/alginate mixture; 10 rats treated with pectin/alginate + olive oil; 10 rats treated with pectin/alginate + olive oil + hydroxytyrosol. Animals were sacrificed 10 days after induction of trinitrobenzene sulfonic acid, receiving 5 days of continuous treatment. Samples of the rectal area were studied and observed under a microscope to determine the damage by Hunter scoring modified, assessing inflammatory infiltration, number of intestinal walls involved, damage to the mucosal architecture, and edema. Results: When the rectum was analyzed in a global way, nonsignificant differences were observed; however, when performing an individualized analysis, statistically significant differences in the inflammatory infiltrate are present in the samples, which were evaluated using the ANOVA and Student-T statistics. Conclusions: Local treatment with the natural antioxidant hydroxytyrosol combined with pectin/alginate and olive oil of inflammatory bowel disease has been shown to be effective against inflammatory infiltration of TNBS-induced colitis.

Objectively and subjectively measured physical activity and its relation to cardiovascular risk factors in older people-Which is most appropriate?

OBJECTIVES: To determine the strength of the association between objectively and subjectively measured physical activity (PA) and cardiovascular risk factors (CVRF) in a sample of older adults to assess which measure of PA is most appropriate for use in this population. STUDY DESIGN AND OUTCOME MEASURES: The study was a cross-sectional analysis of a community-dwelling sample aged 60 years or more (61 women and 34 men). Data collection included anthropometric measurements, blood analytics, and objective and subjective measurements of PA from accelerometers and Yale PA Survey questionnaires, respectively. RESULTS: Although the questionnaire indicated a higher summary index (total units) of PA in men than in women, objective measurements of total PA (mean counts per minute and steps per day) did not differ by sex. However, we obtained different results between women and men when we analyzed the relation between objective and subjective PA parameters and CVRF. In women, parameters that indicate cardiovascular risk, such as body mass index (BMI), waist circumference (WC), glucose, and total cholesterol, negatively correlated with objective PA parameters, while HDLc positively correlated with objective PA parameters and negatively with subjective PA parameters. In men, BMI and WC were negatively correlated with objective PA parameters, while blood cholesterol, LDLc, and triglycerides negatively correlated with subjective PA parameters. CONCLUSIONS: In women, it seems more appropriate to use objective methods to measure PA, while in men, objective and subjective methods seem to be complementary. Both methods of measurement, accelerometers and questionnaires, should be used simultaneously in research studies in older populations to establish precise relationships between PA and cardiovascular risk.

Telomere length maintenance--an ALTernative mechanism.

The Alternative Lengthening of Telomeres (ALT) mechanism is utilised by approximately 10% of human tumours and a higher proportion of some types of sarcomas. ALT+ cell lines and tumours show heterogeneous telomere length, extra-chromosomal circular and linear telomeric DNA, ALT associated promyelocytic bodies (APBs), a high frequency of post-replication exchanges in telomeres (designated as telomere-sister chromatid exchanges, T-SCE) and high instability at a GC-rich minisatellite, MS32 (D1S8). It is clear that there is a link between the minisatellite instability and the mechanism that underpins ALT, however currently the nature of this relationship is uncertain. Single molecule analysis of telomeric DNA from ALT+ cell lines and tumours has revealed complex telomere mutations that have not been seen in cell lines or tumours that express telomerase. These complex telomere mutations cannot be explained by T-SCE but must arise by another inter-molecular process. The break-induced replication (BIR) model that may explain the observed high frequency of T-SCE and the presence of complex telomere mutations is reviewed.