A versatile laser-based apparatus for time-resolved ARPES with micro-scale spatial resolution

We present the development of a versatile apparatus for 6.2 eV laser-based time and angle-resolved photoemission spectroscopy with micrometer spatial resolution (time-resolved μ-ARPES). With a combination of tunable spatial resolution down to ∼11 μm, high energy resolution (∼11 meV), near-transform-limited temporal resolution (∼280 fs), and tunable 1.55 eV pump fluence up to 3 mJ/cm2, this time-resolved μ-ARPES system enables the measurement of ultrafast electron dynamics in exfoliated and inhomogeneous materials. We demonstrate the performance of our system by correlating the spectral broadening of the topological surface state of Bi2Se3 with the spatial dimension of the probe pulse, as well as resolving the spatial inhomogeneity contribution to the observed spectral broadening. Finally, after in situ exfoliation, we performed time-resolved μ-ARPES on a ∼30 μm flake of transition metal dichalcogenide WTe2, thus demonstrating the ability to access ultrafast electron dynamics with momentum resolution on micro-exfoliated materials.

Modulation of human thrombopoietin receptor conformations uncouples JAK2 V617F-driven activation from cytokine-induced stimulation

The thrombopoietin receptor (TpoR) plays a central role in myeloproliferative neoplasms (MPNs). Mutations in JAK2, calreticulin, or TpoR itself drive the constitutive activation of TpoR and uncontrolled proliferation and differentiation of hematopoietic stem cells and progenitors. The JAK2 V617F mutation is responsible for most MPNs, and all driver mutants induce pathologic TpoR activation. Existing therapeutic strategies have focused on JAK2 kinase inhibitors that are unable to differentiate between the mutated MPN clone and healthy cells. Surprisingly, the targeting of TpoR itself has remained poorly explored despite its central role in pathology. Here, we performed a comprehensive characterization of human TpoR activation under physiological and pathological conditions, focusing on the JAK2 V617F mutant. Using a system of controlled dimerization of the transmembrane and cytosolic domains of TpoR, we discovered that human TpoR (hTpoR) adopts different dimeric conformations upon Tpo-induced vs JAK2 V617F-mediated activation. We identified the amino acids and specific dimeric conformation of hTpoR responsible for activation in complex with JAK2 V617F and confirmed our findings in the full-length receptor context in hematopoietic cell lines and primary bone marrow cells. Remarkably, we found that the modulation of hTpoR conformations by point mutations allowed for specific inhibition of JAK2 V617F-driven activation without affecting Tpo-induced signaling. Our results demonstrate that modulation of the hTpoR conformation is a viable therapeutic strategy for JAK2 V617F-positive MPNs and set the path for novel drug development by identifying precise residues of hTpoR involved in JAK2 V617F-specific activation.

[Iron deficiency and anemia in junior women's competitive sport]

An iron deficient athlete is likely to develop iron deficiency anemia, a pathology that may lead to a decrease in performance. If adult athletes, women and men, are aware of the need for regular monitoring, young people under 18 are not necessarily aware of the risks associated with competitive sports practice in the presence of anemia. Even if the guidelines are well known and described, a lack of regular monitoring is found for the aforementioned age group. In junior female athletes practicing basketball, a significant rate of iron deficiency or even iron deficiency anemia was found during annual analyses. The authors wish to emphasize the importance of regular medical and laboratory follow-up for younger athletes who often no longer have a pediatrician and no attending physician.

Constitutive activation and oncogenicity are mediated by loss of helical structure at the cytosolic boundary of thrombopoietin receptor mutant dimers

Dimerization of the thrombopoietin receptor (TpoR) is necessary for receptor activation and downstream signaling through activated Janus kinase 2. We have shown previously that different orientations of the transmembrane (TM) helices within a receptor dimer can lead to different signaling outputs. Here we addressed the structural basis of activation for receptor mutations S505N and W515K that induce myeloproliferative neoplasms. We show using in vivo bone marrow reconstitution experiments that ligand-independent activation of TpoR by TM asparagine (Asn) substitutions is proportional to the proximity of the Asn mutation to the intracellular membrane surface. Solid-state NMR experiments on TM peptides indicate a progressive loss of helical structure in the juxtamembrane (JM) R/KWQFP motif with proximity of Asn substitutions to the cytosolic boundary. Mutational studies in the TpoR cytosolic JM region show that loss of the helical structure in the JM motif by itself can induce activation, but only when localized to a maximum of 6 amino acids downstream of W515, the helicity of the remaining region until Box 1 being required for receptor function. The constitutive activation of TpoR mutants S505N and W515K can be inhibited by rotation of TM helices within the TpoR dimer, which also restores helicity around W515. Together these data allow us to develop a general model for activation of TpoR and to explain the critical role of the JM W515 residue in the regulation of the activity of the receptor.

940. First situational diagnosis of the implementation of Antimicrobial Stewardship Programs in Mexican Hospitals, 2021

Background

The development of antimicrobial stewardship programs (ASP) can help to improve the quality of care and contain the growing problem of antimicrobial resistance (AMR). In Mexico, there is little evidence on the design, implementation and evaluation of hospital ASP. The objective of this study is to present a situational diagnosis of the ASP structure, processes implemented and monitoring of results obtained in a sample of Mexican hospitals.

Methods

An online survey directed to ASP teams was applied to a purposive sample of 40 hospitals that perform regular antimicrobial stewardship activities in Mexico, during the last trimester of 2021. The survey was based on the ‘core elements’ instruments developed by the CDC and WHO.

Results

Forty hospitals (62% public and 38% private) were surveyed in 13 states in Mexico regarding ASP basic elements. Infrastructure and Organization elements: on average 52% of these hospitals carry basic actions that refer to: written ASP document and annual plan (46%); allocated human resources (68%); availability of material resources (59%) and use of technological platforms (37%). Processes: development of hospital treatment guidelines (49%); educational interventions (40%); persuasive and feedback interventions (42%); and in greater proportion, restrictive interventions (77%). Monitoring activities: interventions (25%); antimicrobial consumption (73%) and AMR (85%)

Conclusion

This first diagnosis serves as a baseline to determine the current state of ASP implementation per hospital and in the country. It also reflects on the ASP heterogeneity, that should be addressed by national policies. The greatest challenge lies in the program governance, and the systematic monitoring of the implementation of ASP interventions.

Disclosures

Anahí Dreser, PhD, MSD: Grant/Research Support.

Ubiquitous defect-induced density wave instability in monolayer graphene

Quantum materials are notoriously sensitive to their environments, where small perturbations can tip a system toward one of several competing ground states. Graphene hosts a rich assortment of such competing phases, including a bond density wave instability ("Kekulé distortion") that couples electrons at the K/K' valleys and breaks the lattice symmetry. Here, we report observations of a ubiquitous Kekulé distortion across multiple graphene systems. We show that extremely dilute concentrations of surface atoms (less than three adsorbed atoms every 1000 graphene unit cells) can self-assemble and trigger the onset of a global Kekulé density wave phase. Combining complementary momentum-sensitive angle-resolved photoemission spectroscopy (ARPES) and low-energy electron diffraction (LEED) measurements, we confirm the presence of this density wave phase and observe the opening of an energy gap. Our results reveal an unexpected sensitivity of the graphene lattice to dilute surface disorder and show that adsorbed atoms offer an attractive route toward designing novel phases in two-dimensional materials.

JAK inhibitors and COVID-19

During SARS-CoV-2 infection, the innate immune response can be inhibited or delayed, and the subsequent persistent viral replication can induce emergency signals that may culminate in a cytokine storm contributing to the severe evolution of COVID-19. Cytokines are key regulators of the immune response and virus clearance, and, as such, are linked to the—possibly altered—response to the SARS-CoV-2. They act via a family of more than 40 transmembrane receptors that are coupled to one or several of the 4 Janus kinases (JAKs) coded by the human genome, namely JAK1, JAK2, JAK3, and TYK2. Once activated, JAKs act on pathways for either survival, proliferation, differentiation, immune regulation or, in the case of type I interferons, antiviral and antiproliferative effects. Studies of graft-versus-host and systemic rheumatic diseases indicated that JAK inhibitors (JAKi) exert immunosuppressive effects that are non-redundant with those of corticotherapy. Therefore, they hold the potential to cut-off pathological reactions in COVID-19. Significant clinical experience already exists with several JAKi in COVID-19, such as baricitinib, ruxolitinib, tofacitinib, and nezulcitinib, which were suggested by a meta-analysis (Patoulias et al.) to exert a benefit in terms of risk reduction concerning major outcomes when added to standard of care in patients with COVID-19. Yet, only baricitinib is recommended in first line for severe COVID-19 treatment by the WHO, as it is the only JAKi that has proven efficient to reduce mortality in individual randomized clinical trials (RCT), especially the Adaptive COVID-19 Treatment Trial (ACTT-2) and COV-BARRIER phase 3 trials. As for secondary effects of JAKi treatment, the main caution with baricitinib consists in the induced immunosuppression as long-term side effects should not be an issue in patients treated for COVID-19.

We discuss whether a class effect of JAKi may be emerging in COVID-19 treatment, although at the moment the convincing data are for baricitinib only. Given the key role of JAK1 in both type I IFN action and signaling by cytokines involved in pathogenic effects, establishing the precise timing of treatment will be very important in future trials, along with the control of viral replication by associating antiviral molecules.

Immunoglobulin Heavy Chain High-Throughput Sequencing in Pediatric B-Precursor Acute Lymphoblastic Leukemia: Is the Clonality of the Disease at Diagnosis Related to Its Prognosis?

High-throughput sequencing (HTS) of the immunoglobulin heavy chain (IgH) locus is a recent very efficient technique to monitor minimal residual disease of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). It also reveals the sequences of clonal rearrangements, therefore, the multiclonal structure, of BCP-ALL. In this study, we performed IgH HTS on the diagnostic bone marrow of 105 children treated between 2004 and 2008 in Belgium for BCP-ALL in the European Organization for Research and Treatment of Cancer (EORTC)-58951 clinical trial. Patients were included irrespectively of their outcome. We described the patterns of clonal complexity at diagnosis and investigated its association with patients' characteristics. Two indicators of clonal complexity were used, namely, the number of foster clones, described as clones with similar D-N₂-J rearrangements but other V-rearrangement and N₁-joining, and the maximum across all foster clones of the number of evolved clones from one foster clone. The maximum number of evolved clones was significantly higher in patients with t(12;21)/ETV6:RUNX1. A lower number of foster clones was associated with a higher risk group after prephase and t(12;21)/ETV6:RUNX1 genetic type. This study observes that clonal complexity as accessed by IgH HTS is linked to prognostic factors in childhood BCP-ALL, suggesting that it may be a useful diagnostic tool for BCP-ALL status and prognosis.

Targets in MPNs and potential therapeutics

Philadelphia-negative classical Myeloproliferative Neoplasms (MPNs), including Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF), are clonal hemopathies that emerge in the hematopoietic stem cell (HSC) compartment. MPN driver mutations are restricted to specific exons (14 and 12) of Janus kinase 2 (JAK2), thrombopoietin receptor (MPL/TPOR) and calreticulin (CALR) genes, are involved directly in clonal myeloproliferation and generate the MPN phenotype. As a result, an increased number of fully functional erythrocytes, platelets and leukocytes is observed in the peripheral blood. Nevertheless, the complexity and heterogeneity of MPN clinical phenotypes cannot be solely explained by the type of driver mutation. Other factors, such as additional somatic mutations affecting epigenetic regulators or spliceosomes components, mutant allele burdens and modifiers of signaling by driver mutants, clonal architecture and the order of mutation acquisition, signaling events that occur downstream of a driver mutation, the presence of specific germ-line variants, the interaction of the neoplastic clone with bone marrow microenvironment and chronic inflammation, all can modulate the disease phenotype, influence the MPN clinical course and therefore, might be useful therapeutic targets.

Is the unstable ataxic hand of Alajouanine and Akerman a distinct contribution?

We discuss from a historical perspective whether the 1931 description of the "unstable ataxic hand" by Théophile Alajouanine, the fifth successor of Charcot at la Salpêtrière, and the Brazilian neurologist Abraham Akerman, then studying in France, merits being considered a distinct contribution vis-à-vis the earlier description by Oppenheim of the "useless hand syndrome". The specific object of the article by Alajouanine and Akerman was a semiologic sign, namely a pseudoathetosis localized in the hand, while the original description by Oppenheim of the symptom-complex that came to be known as useless hand syndrome did not include an abnormal movement. Moreover, as a result of the useless hand syndrome originating from a clinical classification of multiple sclerosis based on the localization of the lesions, it involves topographic and etiologic diagnoses specificities. In contrast, the unstable ataxic hand can be observed in the useless hand syndrome and other syndromes involving predominantly sensory symptoms, such as "numb clumsy hands" due to high cervical spondylosis or extramedullary tumor, and the "cortical sensory syndrome" most commonly due to parietal stroke. Because it had not been thoroughly described in the context of a symptom-complex, Alajouanine and Akerman's unstable ataxic hand merits being considered a distinct and valuable contribution.

[Hallux Rigidus: first metatarsophalangeal arthrosis Symptoms and current treatments]

Metatarsophalangeal arthritis of the first ray of the foot, also known as hallux rigidus, is an invalidating cause of walking that is still underestimated. It is associated to a local deformation of the first ray with a limitation of the dorsal mobilization of the joint, affecting thus the propulsion of the foot. Several stages of the disease exist, and symptoms as well as the treatment will depend on the moment of the consultation. In this paper, we present the different clinical pictures and adapted treatments according to the stage of the disease, and we share our results of a new modality of surgery that conserves the articular mobility of the joint.

Lithium treatment reverses irradiation-induced changes in rodent neural progenitors and rescues cognition

Cranial radiotherapy in children has detrimental effects on cognition, mood, and social competence in young cancer survivors. Treatments harnessing hippocampal neurogenesis are currently of great relevance in this context. Lithium, a well-known mood stabilizer, has both neuroprotective, pro-neurogenic as well as antitumor effects, and in the current study we introduced lithium treatment 4 weeks after irradiation. Female mice received a single 4 Gy whole-brain radiation dose on postnatal day (PND) 21 and were randomized to 0.24% Li2CO₃ chow or normal chow from PND 49 to 77. Hippocampal neurogenesis was assessed on PND 77, 91, and 105. We found that lithium treatment had a pro-proliferative effect on neural progenitors, but neuronal integration occurred only after it was discontinued. Also, the treatment ameliorated deficits in spatial learning and memory retention observed in irradiated mice. Gene expression profiling and DNA methylation analysis identified two novel factors related to the observed effects, Tppp, associated with microtubule stabilization, and GAD2/65, associated with neuronal signaling. Our results show that lithium treatment reverses irradiation-induced loss of hippocampal neurogenesis and cognitive impairment even when introduced long after the injury. We propose that lithium treatment should be intermittent in order to first make neural progenitors proliferate and then, upon discontinuation, allow them to differentiate. Our findings suggest that pharmacological treatment of cognitive so-called late effects in childhood cancer survivors is possible.

The impact of a nationwide hands-on workshop on the diagnostic rates and management of obstetrical anal sphincter Injuries in Israel

AIM

The aim was to evaluate the influence of a half day, hands-on, workshop on the detection and repair of obstetric anal sphincter injuries (OASIs).

METHOD

Starting in February 2011, hands-on workshops for the diagnosis and repair of OASIs were delivered by trained urogynaecologists in departments of tertiary medical centres in Israel. The structure of the hands-on workshop resembles the workshop organized at the International Urogynecological Association annual conferences. Participants included medical staff, midwives and surgical residents from each medical centre. We collected data regarding the rate of OASIs, 1 year before and 1 year following the workshop, in 11 medical centres. The study population was composed of parturients with the following inclusion criteria: singleton pregnancy, vertex presentation and vaginal delivery. Pre-viable preterm gestations (< 24 weeks), birth weight < 500 g, stillborn, and those with major congenital anomalies, multifoetal pregnancies, breech presentations and caesarean deliveries were excluded from the analysis.

RESULTS

In the reviewed centres, 70 663 (49.3%) women delivered prior to the workshop (pre-workshop group) and 72 616 (50.7%) women delivered following the workshop (post-workshop group). Third- or fourth-degree perineal tears occurred in 248 women (0.35%) before the workshop, and in 328 (0.45%) following the workshop, a significant increase of 28.7% (P = 0.002). The increase in diagnosis was significant also in women with third-degree tears alone, 226 women (0.32%) before the workshop and 298 (0.41%) following the workshop, an increase of 28.3% (P = 0.005).

CONCLUSION

The detection rate of OASIs has significantly increased following the hands-on workshop. The implementation of such programmes is crucial for increasing awareness and detection rates of OASI following vaginal deliveries.

Direct determination of mode-projected electron-phonon coupling in the time domain

Ultrafast spectroscopies have become an important tool for elucidating the microscopic description and dynamical properties of quantum materials. In particular, by tracking the dynamics of nonthermal electrons, a material’s dominant scattering processes can be revealed. Here, we present a method for extracting the electron-phonon coupling strength in the time domain, using time- and angle-resolved photoemission spectroscopy (TR-ARPES). This method is demonstrated in graphite, where we investigate the dynamics of photoinjected electrons at the K¯ point, detecting quantized energy-loss processes that correspond to the emission of strongly coupled optical phonons. We show that the observed characteristic time scale for spectral weight transfer mediated by phonon-scattering processes allows for the direct quantitative extraction of electron-phonon matrix elements for specific modes.

Room temperature strain-induced Landau levels in graphene on a wafer-scale platform

Graphene is a powerful playground for studying a plethora of quantum phenomena. One of the remarkable properties of graphene arises when it is strained in particular geometries and the electrons behave as if they were under the influence of a magnetic field. Previously, these strain-induced pseudomagnetic fields have been explored on the nano- and micrometer-scale using scanning probe and transport measurements. Heteroepitaxial strain, in contrast, is a wafer-scale engineering method. Here, we show that pseudomagnetic fields can be generated in graphene through wafer-scale epitaxial growth. Shallow triangular nanoprisms in the SiC substrate generate strain-induced uniform fields of 41 T, enabling the observation of strain-induced Landau levels at room temperature, as detected by angle-resolved photoemission spectroscopy, and confirmed by model calculations and scanning tunneling microscopy measurements. Our work demonstrates the feasibility of exploiting strain-induced quantum phases in two-dimensional Dirac materials on a wafer-scale platform, opening the field to new applications.

A redefinition of the modeled responses of mammary glands to once-daily milking

Milking cows once daily is a management tool that has been implemented to improve physical and financial results of seasonal pasture-based dairy farms. The Molly cow model integrates physiology and metabolism of dairy cattle; however, milk production during short-term changes in milking frequency (e.g., 1× milking) is not well represented. The model includes a representation of variable rates of cell quiescence and death. However, the rate constants governing cell death and the return of quiescent to active cells are not affected by milking frequency. An empirical assessment of the problem was conducted, and it was hypothesized that changing the current representation of the rate of cell death in response to short-term 1× milking would more accurately represent active and quiescent cells and improve predictions of milk production. An extra senescent cell flux was added to account for cell loss during periods of 1× milking. Additional changes included a gradual decline in the rate of 1× stimulated senescence during 1× milking, and a structural change in cell cycling between active and quiescent cells during and after short-term 1× milking. Data used for parameter estimation were obtained from 5 studies where 1× milking or different feeding strategies were tested. Parameter estimates of cell loss indicated that 1× milking would affect a small proportion of quiescent cells to cause extra cell death. This added cell senescence was influenced by the length of 1× milking such that cell senescence peaked on d 1 of 1× milking and decayed from that point. The new structure in the model includes a variable rate of cell death in response to 1× milking and a gradual rate of return of quiescent cells back to the active pool in response to switching to 2× milking after short-term 1× milking. Root mean square errors, mean bias, and slope bias declined by at least 50% for predictions of energy-corrected milk yield and fat percent. The model showed quantitative agreement with production data from short-term 1× milking. The accuracy of predictions was improved and the error was reduced by implementing modifications in the model in response to changes in milking frequency.

Influence of Spin-Orbit Coupling in Iron-Based Superconductors

We report on the influence of spin-orbit coupling (SOC) in Fe-based superconductors via application of circularly polarized spin and angle-resolved photoemission spectroscopy. We combine this technique in representative members of both the Fe-pnictides (LiFeAs) and Fe-chalcogenides (FeSe) with tight-binding calculations to establish an ubiquitous modification of the electronic structure in these materials imbued by SOC. At low energy, the influence of SOC is found to be concentrated on the hole pockets, where the largest superconducting gaps are typically found. This effect varies substantively with the k_{z} dispersion, and in FeSe we find SOC to be comparable to the energy scale of orbital order. These results contest descriptions of superconductivity in these materials in terms of pure spin-singlet eigenstates, raising questions regarding the possible pairing mechanisms and role of SOC therein.

Extremely premature infants: How does death in the delivery room influence mortality rates in two level 3 centers in France?

OBJECTIVES

Mortality rates of very preterm infants may vary considerably between healthcare facilities depending on the neonates' place of inclusion in the cohort study. The objective of this study was to compare the mortality rates of live-born extremely preterm neonates observed in two French tertiary referral hospitals, taking into account the occurrence of neonatal death both in the delivery room and in the neonatal intensive care unit (NICU).

METHODS

Retrospective observational study including all pregnancy terminations, stillbirths and live-born infants within a 22- to 26-week ^0/6 gestational age range was registered by two French level 3 university centers between 2009 and 2013. The mortality rates were compared between the two centers according to two places of inclusion: either the delivery room or the NICU.

RESULTS

A total of 344 infants were born at center A and 160 infants were born at center B. Among the live-born neonates, the rates of neonatal death were similar in center A (54/125, 43.2%) and center B (33/69, 47.8%; P=0.54). However, neonatal death occurred significantly more often in the delivery room at center A (31/54, 57.4%) than at center B (6/33, 18.2%; P<0.001). Finally, the neonatal death rate of live-born very preterm neonates admitted to the NICU was significantly lower in center A (25/94, 26.6%) than in center B (27/63, 42.9%; P=0.03).

CONCLUSIONS

This study points out how the inclusion of deaths in the delivery room when comparing neonatal death rates can lead to a substantial bias in benchmarking studies. Center A and center B each endorsed one of the two models of preferential place of neonatal death (delivery room or NICU) detailed in European studies. The reasons behind the two different models and their impact on how parents perceive supporting their neonate need further investigation.

French Multicentric Evaluation of Recombinant Tissue Factor (Recombiplastin) for Determination of Prothrombin Time

Recombiplastin, a recombinant a human tissue factor, elaborated by Ortho Diagnostic Systems, produced by Baculovirus and relipidated with highly purified phospholipids, was tested as a new reagent for determining prothrombin time (PT) in a French multicentric study. Its intralaboratory- performances, including sensitivity, repeatability, reproducibility and stability, were explored to establish whether its use would reduce the interlaboratory dispersion of PT values, and therefore improve the standardization of oral anticoagulant treatment.

The 9 university hospital hematology laboratories involved in this study used the same type of instrument (KC 10). For 10 consecutive days, they determined PTS on a normal plasma pool, plasma dilutions of 1/2, 1/3 and 1/8, 3 identical lyophilized calibrated plasmas, as well as plasmas from 20 normal subjects, 50 patients on oral anticoagulant therapy with Recombiplastin which has an International Sensitivity Index (ISI) of 1, and 2 commercial thromboplastin extracts (ISI #1 or 2). In the patients on anticoagulants, factors VII, X and V were measured when results were conflicting.

The intra and interlaboratory reproducibilities of Recombiplastin, calculated on the basis of either PTS expressed in seconds, or of the International Normalized Ratio (INR), were good, with coefficients of variation (CV) similar to those observed with the 5 other reagents used by the different laboratories (2% <CV <8%).

The stability of Recombiplastin was excellent, with no variation in PT after 72 h of incubation at 37° C.

A normal PT of 12 s was obtained with Recombiplastin, similar to the values found for the reagents with ISI #2. In the patients on anticoagulants, Recombiplastin gave the longest coagulation times (PTRecombipiastin = 64.2 s vs PTNeoPlastin = 32.8 s, and PTThromborel = 54.4 s). These results suggest that Recombiplastin is highly sensitive to the changes in coagulation induced by anticoagulants. Recombiplastin was more sensitive to factor VII deficiency than any of the other reagents, even those with ISI #1.

The coefficients of correlation between the INRS calculated on the basis of the PTS obtained with Recombiplastin and the INRS based on the PTS for other thromboplastins, were satisfactory (0.85 <R <0.95) but a breakpoint in the slope of the regression curves was observed when INR >4. This observation requires further investigation, particularly in connection with the exact ISI values for Recombiplastin and the other thromboplastins used in this study.

In conclusion, Recombiplastin is stable and sensitive and gives accurate reproducible results. However, the behavior of Recombiplastin is slightly different from that of the commercial reagents whether their ISI is 1 or 2, and its use did not reduce the interlaboratory dispersion of PT values.

Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence

The possibility of driving phase transitions in low-density condensates through the loss of phase coherence alone has far-reaching implications for the study of quantum phases of matter. This has inspired the development of tools to control and explore the collective properties of condensate phases via phase fluctuations. Electrically gated oxide interfaces^1,2, ultracold Fermi atoms^3,4 and cuprate superconductors^5,6, which are characterized by an intrinsically small phase stiffness, are paradigmatic examples where these tools are having a dramatic impact. Here we use light pulses shorter than the internal thermalization time to drive and probe the phase fragility of the Bi₂Sr₂CaCu₂O_8+δ cuprate superconductor, completely melting the superconducting condensate without affecting the pairing strength. The resulting ultrafast dynamics of phase fluctuations and charge excitations are captured and disentangled by time-resolved photoemission spectroscopy. This work demonstrates the dominant role of phase coherence in the superconductor-to-normal state phase transition and offers a benchmark for non-equilibrium spectroscopic investigations of the cuprate phase diagram.

Treatment of Progressive Systemic Sclerosis by Plasma Exchange: Long-term Results in 40 Patients

The efficacy of plasma exchanges (PE) during the course of scleroderma has only been investigated for short periods. The aim of this study was to follow patients over a long enough period to observe the course of the clinical and paraclinical symptoms in the short, medium, and long term. Forty patients, 24 women and 16 men, were treated by PE and observed for 1–3, 3–12 and over 12 months. Immunological, biological and clinical course and any undesirable side effects were evaluated using a detailed questionnaire. Concomitant therapies were reported and most frequently consisted of corticosteroids, colchicine, factor XIII or vasodilators (nifedipine, captopril). The therapeutic effectiveness of PE was assessed on the basis of improvements in cutaneous, digestive, joint, muscular, lung, cardiovascular and renal lesions. Our findings confirmed the effectiveness of short-term PE on scleroderma (52% of the patients improved during the first 3 months). However, this improvement was transient (5% improvement between 3 and 12 months and only 2.5% over 12 months) and limited to the cutaneous and muscular lesions. Thus, PE cannot be recommended for the treatment of progressive systemic sclerosis.

The Graduating European Dentist: Contemporaneous Methods of Teaching, Learning and Assessment in Dental Undergraduate Education

It is often the case that good teachers just "intuitively" know how to teach. Whilst that may be true, there is now a greater need to understand the various processes that underpin both the ways in which a curriculum is delivered, and the way in which the students engage with learning; curricula need to be designed to meet the changing needs of our new graduates, providing new, and robust learning opportunities, and be communicated effectively to both staff and students. The aim of this document is to draw together robust and contemporaneous methods of teaching, learning and assessment that help to overcome some of the more traditional barriers within dental undergraduate programmes. The methods have been chosen to map specifically to The Graduating European Dentist, and should be considered in parallel with the benchmarking process that educators and institutions employ locally.

Post-traumatic balance disorder

The causes of balance disorder are many and various, and the subjective syndrome of cranial trauma patients is diagnosed by elimination. Progress in otoneurologic functional exploration and brain imaging, however, now generally allow this functional complaint to be given an objective basis. In recent years, new diagnoses have improved recognition of such pathologies in the appraisal of corporal injury for compensation purposes. The present article seeks to detail etiology and, by a review of the literature, to determine factors liable to influence management and appraisal in particular.

Long- versus Short-Range Scattering in Doped Epitaxial Graphene

Tuning the electronic properties of graphene by adatom deposition unavoidably introduces disorder into the system, which directly affects the single-particle excitations and electrodynamics. Using angle-resolved photoemission spectroscopy (ARPES) we trace the evolution of disorder in graphene by thallium adatom deposition and probe its effect on the electronic structure. We show that the signatures of quasiparticle scattering in the photoemission spectral function can be used to identify thallium adatoms, although charged, as efficient short-range scattering centers. Employing a self-energy model for short-range scattering, we are able to extract a δ-like scattering potential δ = -3.2 ± 1 eV. Therefore, isolated charged scattering centers do not necessarily act just as good long-range (Coulomb) scatterers but can also act as efficient short-range (δ-like) scatterers; in the case of thallium, this happens with almost equal contributions from both mechanisms.

Efficacy of ginger-based treatments against infection with Gyrodactylus turnbulli in the guppy (Poecilia reticulata (Peters))

Monogenean infections of commercially farmed fishes are responsible for significant economic losses and existing chemical therapeutants, often stressful to the fish, pose associated risks. As part of a recent trend to move towards the use of alternative, plant-based remedies for commonly occurring aquaculture-related diseases, the efficiency of ginger (Zingiber officinale) was investigated against the monogenean parasite Gyrodactylus turnbulli in the guppy. In vitro trials revealed the clear anti-parasitic effects of ginger. Ethanolic and aqueous extracts, prepared from freeze dried ginger, were tested. An increase in extract concentration was associated with reduced time to parasite immobilisation, with ethanolic extract being more efficient; at 75 and 200ppt aqueous ginger extract parasites died at 65.6±2.8 and 1.8±0.2min, respectively, whereas at 5 and 40ppt ethanolic extract parasites died at 26.1±0.7 and 4.9±0.3min, respectively. Bathing G. turnbulli-infected fish in ethanolic ginger extract (i.e. 5 and 7.5ppt for 90 and 30min, respectively) significantly reduced infection prevalence and intensity when compared to the water and ethanol controls. The higher concentration (i.e. 7.5ppt) proved as equally effective as Praziquantel, the conventionally used chemical treatment for gyrodactylosis, with the fish appearing to be completely cleared of the infection in both cases. Oral treatments of G. turnbulli-infected guppies with diets supplemented with 10 and 20% ginger powder proved to be ineffective in decreasing parasite load. These findings demonstrate that immersion in ginger extract offers an effective, alternative treatment against monogenean infection in fish.

REFINE: a randomized trial comparing cyclosporine A and tacrolimus on fibrosis after liver transplantation for hepatitis C

REFINE was a 12-month, prospective, open-label study in 356 patients receiving de novo liver transplantation for hepatitis C virus (HCV) cirrhosis, randomized to cyclosporine A (CsA) or tacrolimus with (i) no steroids, IL-2 receptor antibody induction and mycophenolic acid, or (ii) slow steroid tapering. The primary analysis population based on availability of liver biopsies comprised 165 patients (88 CsA, 77 tacrolimus). There was no difference in the primary endpoint, fibrosis stage ≥2 at 12 months, which occurred in 63/88 CsA-treated patients (71.6%) and 52/77 tacrolimus-treated patients (67.5%) (odds ratio [OR] 1.11; 95% CI 0.56, 2.21; p = 0.759). Similarly, no significant between-group difference occurred at month 24 (OR 1.15; 95% CI 0.47, 2.80; p = 0.767). Among steroid-free patients, fibrosis score ≥2 was significantly less frequent with CsA versus tacrolimus at month 12 (7/37 [18.9%] vs. 16/38 [42.1%]; p = 0.029). HCV viral load was similar in both the tacrolimus- and CsA-treated cohorts. Mean blood glucose was significantly higher with tacrolimus from day 15 onward. Biopsy-proven acute rejection, graft loss and death were similar. These results showed no differences in posttransplant HCV-induced liver fibrosis between patients treated with CsA or tacrolimus in steroid-containing regimens, whereas CsA in steroid-free protocols was associated with reduced severity of fibrosis progression at 1 year posttransplant.

Polarity-driven surface metallicity in SmB6

By a combined angle-resolved photoemission spectroscopy and density functional theory study, we discover that the surface metallicity is polarity driven in SmB6. Two surface states, not accounted for by the bulk band structure, are reproduced by slab calculations for coexisting B6 and Sm surface terminations. Our analysis reveals that a metallic surface state stems from an unusual property, generic to the (001) termination of all hexaborides: the presence of boron 2p dangling bonds, on a polar surface. The discovery of polarity-driven surface metallicity sheds new light on the 40-year old conundrum of the low-temperature residual conductivity of SmB6, and raises a fundamental question in the field of topological Kondo insulators regarding the interplay between polarity and nontrivial topological properties.

Surface-enhanced charge-density-wave instability in underdoped Bi2Sr(2-x)La(x)CuO(6+δ)

Neutron and X-ray scattering experiments have provided mounting evidence for spin and charge ordering phenomena in underdoped cuprates. These range from early work on stripe correlations in Nd-LSCO to the latest discovery of charge-density-waves in YBa2Cu3O(6+x). Both phenomena are characterized by a pronounced dependence on doping, temperature and an externally applied magnetic field. Here, we show that these electron-lattice instabilities exhibit also a previously unrecognized bulk-surface dichotomy. Surface-sensitive electronic and structural probes uncover a temperature-dependent evolution of the CuO2 plane band dispersion and apparent Fermi pockets in underdoped Bi2 Sr(2-x) La(x) CuO(6+δ) (Bi2201), which is directly associated with an hitherto-undetected strong temperature dependence of the incommensurate superstructure periodicity below 130 K. In stark contrast, the structural modulation revealed by bulk-sensitive probes is temperature-independent. These findings point to a surface-enhanced incipient charge-density-wave instability, driven by Fermi surface nesting. This discovery is of critical importance in the interpretation of single-particle spectroscopy data, and establishes the surface of cuprates and other complex oxides as a rich playground for the study of electronically soft phases.

Layer-by-layer entangled spin-orbital texture of the topological surface state in Bi2Se3

We study Bi(2)Se(3) by polarization-dependent angle-resolved photoemission spectroscopy and density-functional theory slab calculations. We find that the surface state Dirac fermions are characterized by a layer-dependent entangled spin-orbital texture, which becomes apparent through quantum interference effects. This explains the discrepancy between the spin polarization obtained in spin and angle-resolved photoemission spectroscopy-ranging from 20% to 85%-and the 100% value assumed in phenomenological models. It also suggests a way to probe the intrinsic spin texture of topological insulators, and to continuously manipulate the spin polarization of photoelectrons and photocurrents all the way from 0 to ±100% by an appropriate choice of photon energy, linear polarization, and angle of incidence.

Determining the surface-to-bulk progression in the normal-state electronic structure of Sr(2)RuO(4) by angle-resolved photoemission and density functional theory

We revisit the normal-state electronic structure of Sr(2)RuO(4) by angle-resolved photoemission spectroscopy with improved data quality, as well as ab initio band structure calculations in the local-density approximation with the inclusion of spin-orbit coupling. We find that the current model of a single surface layer (√2×√2)R45° reconstruction does not explain all detected features. The observed depth-dependent signal degradation, together with the close quantitative agreement with the slab calculations based on the surface crystal structure as determined by low-energy electron diffraction, reveal that-at a minimum-the subsurface layer also undergoes a similar although weaker reconstruction. This model accounts for all features-a key step in understanding the electronic structure-and indicates a surface-to-bulk progression of the electronic states driven by structural instabilities. Finally, we find no evidence for other phases stemming from either topological bulk properties or, alternatively, the interplay between spin-orbit coupling and the broken symmetry of the surface.

Habitat use by Collared Crescentchest (Melanopareia torquata) in a Cerrado in southeastern Brazil: implications for management

The Collared Crescentchest (Melanopareia torquata) is a small insectivore endemic to the Cerrado. We examine the habitat use of this bird in a preserved Cerrado area in southeastern Brazil. Despite its occurrence in grassland with shrubs, the species used these areas less frequently than expected. The Collared Crescentchest mainly used areas of campo cerrado, but it was not recorded in a disturbed one. The common occurrence of exotic grass (U. decumbens) and cattle grazing may have brought about factors for its occurrence. However, the preference for native grasses may indicate an adverse indirect relationship against its occurence as there is competition between native and exotic grasses in the Cerrado. The presence of the Collared Crescentchest included the highest density of tall shrubs (>1 m) and native grasses. Conservation of the species should involve preserved areas of campo cerrado with a dominance of native grasses and tall shrubs.

Na2IrO3 as a novel relativistic Mott insulator with a 340-meV gap

We study Na2IrO3 by angle-resolved photoemission spectroscopy, optics, and band structure calculations in the local-density approximation (LDA). The weak dispersion of the Ir 5d-t(2g) manifold highlights the importance of structural distortions and spin-orbit (SO) coupling in driving the system closer to a Mott transition. We detect an insulating gap Δ(gap)≃340  meV which, at variance with a Slater-type description, is already open at 300 K and does not show significant temperature dependence even across T(N)≃15  K. An LDA analysis with the inclusion of SO and Coulomb repulsion U reveals that, while the prodromes of an underlying insulating state are already found in LDA+SO, the correct gap magnitude can only be reproduced by LDA+SO+U, with U=3  eV. This establishes Na2IrO3 as a novel type of Mott-like correlated insulator in which Coulomb and relativistic effects have to be treated on an equal footing.

An update on adenomyosis

Adenomyosis is a common benign uterine pathology that is defined by the presence of islands of ectopic endometrial tissue within the myometrium. It is asymptomatic in one third of cases, but when there are clinical signs they remain non-specific. It can often be misdiagnosed on sonography as it may be taken to be multiple uterine leiomyomata or endometrial thickening, both of which have a different prognosis and treatment. Adenomyosis is often associated with hormone-dependent pelvic lesions (myoma, endometriosis, or endometrial hyperplasia). It is less commonly connected to infertility or obstetrical complications and indeed any direct relationship remains controversial. The purpose of imaging is to make the diagnosis, to determine the extent of spread (focal or diffuse, superficial or deep adenomyosis, adenomyoma), and to check whether there is any associated disease, in particular endometriosis. The aim of this article is to provide assistance in recognising adenomyosis on imaging and to identify the pathologies that are commonly associated with it in order to guide the therapeutic management of symptomatic patients. Pelvic ultrasonography is the first line investigation. Sonohysterography can assist with diagnosis in some cases (pseudothickening of the endometrium seen on sonography). MRI may be used in addition to sonography to back up the diagnosis and to look for any associated disease.

Routine induction therapy in living donor liver transplantation prevents rejection but may promote recurrence of hepatitis C

BACKGROUND

Routine induction therapy in living donor liver transplantation (LDLT) has not been well described.

METHODS

We reviewed outcomes of induction therapy with rabbit antithymocyte globulin (rATG) or basiliximab within 1 year of LDLT.

RESULTS

Between 2002 and 2007, 184 adults underwent LDLT and received induction therapy in addition to standard immunosuppression. Acute cellular rejection (ACR) developed in 17 of 130 patients (13.1%) who received rATG and 13 of 54 patients (24.1%) who received basiliximab (P = .066). The interval between transplantation and rejection as well as rejection severity was similar in patients who received rATG and those who received basiliximab. Hepatitis C (HCV) recurrence requiring initiation of antiviral therapy was more common in patients who received rATG compared with basiliximab (34.5% vs 8.7%; P = .021), and in those who received induction combined with tacrolimus as opposed to cyclosporine (38.5% vs 3.9%; P = .001). rATG and basiliximab were associated with excellent patient and graft survivals well as low rates of opportunistic infections and malignancies.

CONCLUSION

Induction with rATG or basiliximab was well tolerated and highly effective at preventing ACR within 1 year of LDLT, but may be associated with a higher risk of clinically significant HCV recurrence in some patients.