Direct measurement of discrete valley and orbital quantum numbers in bilayer graphene.

The high magnetic field electronic structure of bilayer graphene is enhanced by the spin, valley isospin, and an accidental orbital degeneracy, leading to a complex phase diagram of broken symmetry states. Here, we present a technique for measuring the layer-resolved charge density, from which we directly determine the valley and orbital polarization within the zero energy Landau level. Layer polarization evolves in discrete steps across 32 electric field-tuned phase transitions between states of different valley, spin, and orbital order, including previously unobserved orbitally polarized states stabilized by skew interlayer hopping. We fit our data to a model that captures both single-particle and interaction-induced anisotropies, providing a complete picture of this correlated electron system. The resulting roadmap to symmetry breaking paves the way for deterministic engineering of fractional quantum Hall states, while our layer-resolved technique is readily extendable to other two-dimensional materials where layer polarization maps to the valley or spin quantum numbers.The phase diagram of bilayer graphene at high magnetic fields has been an outstanding question, with orders possibly between multiple internal quantum degrees of freedom. Here, Hunt et al. report the measurement of the valley and orbital order, allowing them to directly reconstruct the phase diagram.

Esophagectomy for failed endoscopic therapy in patients with high-grade dysplasia or intramucosal carcinoma.

Endoscopic therapy (ablation +/- endoscopic resection) for high-grade dysplasia and/or intramucosal carcinoma (IMC) of the esophagus has demonstrated promising results. However, there is a concern that a curable, local disease may progress to systemic disease with repeated endotherapy. We performed a retrospective review of patients who underwent esophagectomy after endotherapy at three tertiary care esophageal centers from 2006 to 2012. Our objective was to document the clinical and pathologic outcomes of patients who undergo esophagectomy after failed endotherapy. Fifteen patients underwent esophagectomy after a mean of 13 months and 4.1 sessions of endotherapy for progression of disease (53%), failure to clear disease (33%), or recurrence (13%). Initially, all had Barrett's, 73% had ≥3-cm segments, 93% had a nodule or ulcer, and 91% had multifocal disease upon presentation. High-grade dysplasia was present at index endoscopy in 80% and IMC in 33%, and some patients had both. Final pathology at esophagectomy was T0 (13%), T1a (60%), T1b (20%), and T2 (7%). Positive lymph nodes were found in 20%: one patient was T2N1 and two were T1bN1. Patients with T1b, T2, or N1 disease had more IMC on index endoscopy (75% vs. 18%) and more endotherapy sessions (median 6.5 vs. 3). There have been no recurrences a mean of 20 months after esophagectomy. Clinical outcomes were comparable to other series, but submucosal invasion (27%) and node-positive disease (20%) were encountered in some patients who initially presented with a locally curable disease and eventually required esophagectomy after failed endotherapy. An initial pathology of IMC or failure to clear disease after three treatments should raise concern for loco-regional progression and prompt earlier consideration of esophagectomy.

Evaluation of quality of life in clinical trials of cardiovascular disease.

There is an increasing interest in the use of quality of life methods to assess the benefits of treatment in cardiovascular disease. When selecting dimensions of quality of life and the instruments to measure these dimensions, the key issue is the detection of a response to treatment during the trial. The sensitivity of a variety of instruments appropriate to hypertension, angina and congestive heart failure is reviewed. Quality of life should be assessed in double blind randomized controlled trials. A Health Index must be included to take into account any mortality and morbidity occurring during the trial. Data are presented on the measurement of quality of life in patients taking placebo prior to entering trials of antihypertensive treatment. The variation with age, sex and nationality is discussed. Also reported are the results arising from observer bias in a single-blind trial.

The British-Norwegian migrant study--analysis of parameters of mortality differentials associated with angina.

The prevalence of selected cardiorespiratory symptoms was ascertained by a common mail questionnaire for 73,884 men and women in the United States, Great Britain and Norway. The study groups were identified in the early 1960's and included 30,033 British and Norwegian migrants to the United States and 43,851 non-migrants who resided in Great Britain and Norway. The main study objectives were to contrast the morbidity and mortality experience of the migrant and non-migrant groups in the light of known national differences in mortality from cardiorespiratory diseases in the early 1960's. At that time, the U.S. had the highest death rates from coronary heart disease while Great Britain had the highest rates for lung cancer and for chronic non-specific lung disease. Norway had the lowest rates for all three rubrics. The prevalence of "angina" and other symptoms was ascertained for each of the study groups. Contrary to expectation, angina was reported much more frequently by persons remaining in Britain and Norway than by migrants to the United States. Mortality rates during the five years and responding to the symptoms questionnaire were determined and mortality patterns were evaluated according to the presence or absence of angina. Angina was found to be a strong predictor of cardiovascular mortality. In the absence of angina, it was observed that migrants had similar mortality rates to non-migrants regardless of country of origin. However, the British had higher mortality rates from cardiovascular and from non-cardiovascular causes than the Norwegians. The primary determinant of angina prevalence was found to be migration status. It is believed that this differential was determined primarily by selection of those who migrate, with the migrants to the U.S. being a healthier group than their counterparts remaining in the native country.

Four cardiorespiratory symptoms as predictors of mortality.

The power of four cardiorespiratory symptoms to predict subsequent mortality has been analysed in data derived from a random sample of the population of Great Britain recruited in 1965 and followed for 12.4 years. The associations of respiratory symptoms with all causes of death (except stroke) and of cardiovascular symptoms with death from coronary heart disease were strong. The trends of these two associations over the 12.4 years of the follow-up differed substantially: the relative death rates associated with respiratory symptoms remained throughout at about the same level, while those associated with cardiovascular symptoms declined after four years. The excess premature deaths associated with presence of one or more symptoms at entry represented about a quarter of the observed deaths of men and one tenth of those of women.