Fermi surface and pseudogap evolution in a cuprate superconductor.

The unclear relationship between cuprate superconductivity and the pseudogap state remains an impediment to understanding the high transition temperature (T(c)) superconducting mechanism. Here, we used magnetic field-dependent scanning tunneling microscopy to provide phase-sensitive proof that d-wave superconductivity coexists with the pseudogap on the antinodal Fermi surface of an overdoped cuprate. Furthermore, by tracking the hole-doping (p) dependence of the quasi-particle interference pattern within a single bismuth-based cuprate family, we observed a Fermi surface reconstruction slightly below optimal doping, indicating a zero-field quantum phase transition in notable proximity to the maximum superconducting T(c). Surprisingly, this major reorganization of the system's underlying electronic structure has no effect on the smoothly evolving pseudogap.

Scanning tunnelling microscopy imaging of symmetry-breaking structural distortion in the bismuth-based cuprate superconductors.

A complicating factor in unravelling the theory of high-temperature (high-T(c)) superconductivity is the presence of a 'pseudogap' in the density of states, the origin of which has been debated since its discovery. Some believe the pseudogap is a broken symmetry state distinct from superconductivity, whereas others believe it arises from short-range correlations without symmetry breaking. A number of broken symmetries have been imaged and identified with the pseudogap state, but it remains crucial to disentangle any electronic symmetry breaking from the pre-existing structural symmetry of the crystal. We use scanning tunnelling microscopy to observe an orthorhombic structural distortion across the cuprate superconducting Bi(2)Sr(2)Ca(n-1)Cu(n)O(2n+4+x) (BSCCO) family tree, which breaks two-dimensional inversion symmetry in the surface BiO layer. Although this inversion-symmetry-breaking structure can impact electronic measurements, we show from its insensitivity to temperature, magnetic field and doping, that it cannot be the long-sought pseudogap state. To detect this picometre-scale variation in lattice structure, we have implemented a new algorithm that will serve as a powerful tool in the search for broken symmetry electronic states in cuprates, as well as in other materials.

Quarterly individual outpatients lifestyle counseling after initial inpatients education on type 2 diabetes: the REDIA Prev-2 randomized controlled trial in Reunion Island.

AIMS: This study aimed to describe the 1-year evolution of type 2 diabetes (T2D) patients who attended inpatients education, and to assess whether quarterly outpatients counseling visits by nurses and dietitians can improve metabolic control and health-related behaviours. METHODS: Following in-hospital educational sessions, 398 adult T2D patients were randomized to either attend quarterly individual lifestyle counseling visits by a nurse and a dietitian (intervention group), or receive the usual care (control group). Primary (HbA(1c)) and secondary endpoints (fasting blood glucose, lipids, body mass index, waist circumference, fat mass, blood pressure, diet, physical activity) were assessed at baseline and at 12 months. RESULTS: HbA(1c) changes from baseline to 12 months were -1.74±2.64% (P<0.0001) for the intervention group and -2.02±2.57% (P<0.0001) for the control group. There was no statistically significant difference between the intervention group (n=153) and the controls (n=166) for any of the clinical and biological outcomes. In both groups, total energy and fat intakes decreased significantly from baseline levels. Also, no difference was found between the groups for any dietary outcome. A slight enhancement in sports activity was observed in the intervention group, but the difference between the two groups did not reach statistical significance, and no difference was found concerning any other physical activity scores. CONCLUSION: In this study of adults with T2D, patients significantly improved their metabolic control, and dietary and exercise habits, 1 year after receiving intensive inpatients education, whereas subsequent quarterly outpatients counseling visits with nurses and dietitians have not demonstrated any superiority compared with the usual care.

Negative predictive value of skin tests to neuromuscular blocking agents.

Allergy to neuromuscular blocking agents (NMBAs) is the most important caue of perioperative anaphylaxis in France. The diagnosis relies on a careful clinical history, the search of serum IgE antibodies, and the realization of skin tests. Although the skin tests are the most important tool and their sensitivity is widely recognized, the lack of information about their negative predictive value represents an important issue in the management of patients who require a new procedure with NMBA injection. We present a series of 49 patients with confirmed allergy to NMBAs, six of whom required a subsequent surgery with neuromuscular blockade. Negative skin tests allowed the selection of an alternative NMBA, which was well tolerated in all 6 cases. We found an excellent negative predictive value of skin tests in our series but larger studies are required to properly address this question.

An auxiliary capacitor based ultrafast drive circuit for shear piezoelectric motors.

Shear piezoelectric motors frequently require large voltage changes on very short time scales. Since piezos behave electrically as capacitors, this requires a drive circuit capable of quickly sourcing or sinking a large amount of current at high voltages. Here we describe a novel circuit design using a high voltage amplifier, transistor switching stage, and auxiliary capacitor. This circuit can drive piezoelectric motors at higher speeds and lower costs than conventional methods and with greater flexibility for computer automation. We illustrate its application in a controller for a scanning tunneling microscope coarse approach mechanism and discuss other possible applications and modifications of this circuit.

[Is HbA1c appropriate for the screening of diabetes in general pratice?]. / L'HbA1c peut-elle être utilisée par le praticien pour le dépistage du diabète?

The measurement of glycated haemoglobin (HbA(1c)) is a practical and more sensitive tool than fasting plasma glucose (FPG) in screening type 2 diabetes in current practice. Its use has been limited so far by the variability of the analytical methods. The standardization process is going on, and many laboratories are currently using valid methods. Our study is consistent with the results of other groups who recommended this measurement to identify undiagnosed diabetic patients, that are about 25% to 30% in the French population. The demonstration was provided through a survey including a screening step by both HbA(1c) and G0, and a second exam with a 2 hr OGTT in a sample of positive screenees according to at least one criterion (HbA(1c) >=6% or G0 >=1.26 g/L), as well as in a sample of negative screenees. We showed that nine confirmed diabetic subjects out of ten had HbA(1c) >=6% at the screening step, while only a half had G0 >=1.26 g/L. Conversely, 22% of the positive screenees according to HbA(1c) were not confirmed as diabetic by the OGTT, including however more than half with abnormal glucose values. A chart for practical use is proposed to define patients at risk, the process of screening, and the patient follow-up according to the results of the tests.

Coping and attention: implications for child health and pediatric conditions.

Child health and illness are best conceptualized in terms of the interaction of biological, psychological, and social processes. Among the central factors in biopsychosocial models of health and illness are processes of coping and attention in response to stress. As a guide to research on biopsychosocial processes in child health and illness, a dual-process model of responses to stress is described, distinguishing between stress responses that are involuntary/automatic and those responses that are voluntary/controlled. Research on coping with stress is briefly reviewed, along with research on attentional processes in response to stress. The relationships between coping and attention are highlighted, along with the implications of this research for understanding children's health and illness. Throughout the article, examples are drawn from research on pediatric recurrent abdominal pain to illustrate important aspects of coping and attention.

[Severe anaphylactic reactions after administration of rocuronium]. / Accidents anaphylactiques graves après administration de rocuronium.

The authors report four cases of severe anaphylactic reactions (grade III or IV) to rocuronium bromide. In three of them, it was the first contact with a muscle relaxant. In three patients the reaction was mediated by IgE anti-bodies. A cross-reactivity with other muscle relaxants was existing in two cases (suxamethonium, vecuronium and atracurium in one patient, suxamethonium, vecuronium and pancuronium in the other.

[Anaphylactic shock after a test-dose of aprotinin in pediatric orthopedic surgery]. / Choc anaphylactique après dose-test d'aprotinine en chirurgie orthopédique pédiatrique.

A case of severe anaphylactic shock in a 28-month-old child following a testing-dose of aprotinin during major orthopaedic surgery is reported. Two months earlier, aprotinin had been administered during a similar controlateral surgical procedure. The grade III anaphylactic accident required a 48 h treatment in an intensive care unit. The outcome was favourable. The pin-prick tests were positive for aprotinin, substantiating the diagnosis of anaphylactic shock, whereas the test with specific IgE was negative. The value of current diagnostic tools for aprotinin allergy is discussed. The administration of a testing-dose in a patient previously treated with aprotinin cannot be recommended. Considering the risk for allergy, aprotinin should only be administered for recognized indications such as major orthopaedic surgery. Before any readministration of this agent an assessment by an allergist-anaesthetist is essential for determination of the risk-benefit ratio.