Bogoliubov Quasiparticle on the Gossamer Fermi Surface in Electron-Doped Cuprates

In contrast to hole-doped cuprates, electron-doped cuprates consistently exhibit strong antiferromagnetic correlations with a commensurate ({\pi}, {\pi}) ordering wave vector, leading to the prevalent belief that antiferromagnetic spin fluctuations mediate Cooper pairing in these unconventional superconductors. However, early investigations produced two paradoxical findings: while antiferromagnetic spin fluctuations create the largest pseudogap at "hot spots" in momentum space, Raman scattering and angle-resolved photoemission spectroscopy measurements using the leading-edge method seem to suggest the superconducting gap is also maximized at these locations. This presented a dilemma for spin-fluctuation-mediated pairing: Cooper pairing is strongest at momenta where normal state low energy spectral weight is most suppressed. Here we investigate this dilemma in Nd2-xCexCuO4 using angle-resolved photoemission spectroscopy under significantly improved experimental conditions. The unprecedented signal-to-noise ratio and resolution allow us to directly observe the Bogoliubov quasiparticles, demonstrating the existence and importance of two sectors of states: 1. The reconstructed main band and the states gapped by the antiferromagnetic pseudogap around the hot spots. 2. The gossamer Fermi surface states with distinct dispersion inside the pseudogap, from which Bogoliubov quasiparticle coherence peaks emerge below Tc. Supported by numerical results, we propose that the non-zero modulus of the antiferromagnetic order parameter causes the former, while fluctuations in the antiferromagnetic order parameter orientation are responsible for the latter. Our revelations of the gossamer Fermi surface reconcile the paradoxical observations, deepening our understanding of superconductivity in electron-doped cuprates in particular, and unconventional superconductivity in general.Comment: Submitted version 30 pages, 4 main figures, 8 extended data figures. Accepted version in press at Nature Physic

Changes over time in the effect of marital status on cancer survival

<p>Abstract</p> <p>Background</p> <p>Rates of all-cause and cause-specific mortality are higher among unmarried than married individuals. Cancer survival is also poorer in the unmarried population. Recently, some studies have found that the excess all-cause mortality of the unmarried has increased over time, and the same pattern has been shown for some specific causes of death. The objective of this study was to investigate whether there has been a similar change over time in marital status differences in cancer survival.</p> <p>Methods</p> <p>Discrete-time hazard regression models for cancer deaths among more than 440 000 women and men diagnosed with cancer 1970-2007 at age 30-89 were estimated, using register data encompassing the entire Norwegian population. More than 200 000 cancer deaths during over 2 million person-years of exposure were analyzed.</p> <p>Results</p> <p>The excess mortality of the never-married compared to the married has increased steadily for men, in particular the elderly. Among elderly women, the excess mortality of the never-married compared to the married has increased, and there are indications of an increasing excess mortality of the widowed. The excess mortality of divorced men and women, however, has been stable.</p> <p>Conclusions</p> <p>There is no obvious explanation for the increasing disadvantage among the never-married. It could be due to a relatively poorer general health at time of diagnosis, either because of a more protective effect of partnership in a society that may have become less cohesive or because of more positive selection into marriage. Alternatively, it could be related to increasing differentials with respect to treatment. Today's complex cancer therapy regimens may be more difficult for never-married to follow, and health care interventions directed and adapted more specifically to the broad subgroup of never-married patients might be warranted.</p

SOSORT consensus paper: school screening for scoliosis. Where are we today?

This report is the SOSORT Consensus Paper on School Screening for Scoliosis discussed at the 4th International Conference on Conservative Management of Spinal Deformities, presented by SOSORT, on May 2007. The objectives were numerous, 1) the inclusion of the existing information on the issue, 2) the analysis and discussion of the responses by the meeting attendees to the twenty six questions of the questionnaire, 3) the impact of screening on frequency of surgical treatment and of its discontinuation, 4) the reasons why these programs must be continued, 5) the evolving aim of School Screening for Scoliosis and 6) recommendations for improvement of the procedure

Human blood-based exposure levels of persistent organic pollutant (POP) mixtures antagonise androgen receptor transactivation and translocation

INTRODUCTION:Human exposure to persistent organic pollutants (POPs) has been linked to genitourinary health-related conditions such as decreased sperm quality, hypospadias, and prostate cancer (PCa). Conventional risk assessment of POPs focuses on individual compounds. However, in real life, individuals are exposed to many compounds simultaneously. This might lead to combinatorial effects whereby the global effect of the mixture is different from the effect of the single elements or subgroups. POP mixtures may act as endocrine disruptors via the androgen receptor (AR) and potentially contribute to PCa development. AIM:To determine the endocrine disrupting activity of a POP mixture and sub-mixtures based upon exposure levels detected in a human Scandinavian population, on AR transactivation and translocation in vitro. MATERIALS AND METHODS:The Total POP mixture combined 29 chemicals modelled on the exposure profile of a Scandinavian population and 6 sub-mixtures: brominated (Br), chlorinated (Cl), Cl + Br, perfluorinated (PFAA), PFAA + Br, PFAA + Cl, ranging from 1/10× to 500× relative to what is found in human blood. Transactivation was measured by reporter gene assay (RGA) and translocation activity was measured by high content analysis (HCA), each using stably transfected AR model cell lines. RESULTS:No agonist activity in terms of transactivation and translocation was detected for any POP mixtures. In the presence of testosterone the Cl + Br mixture at 100× and 500× blood level antagonised AR transactivation, whereas the PFAA mixture at blood level increased AR transactivation (P &lt; 0.05). In the presence of testosterone the Cl and PFAA + Br mixtures at 1/10×, 1×, and 50× blood level antagonised AR translocation (P &lt; 0.05). CONCLUSION:Taken together, some combinations of POP mixtures can interfere with AR translocation. However, in the transactivation assay, these combinations did not affect gene transactivation. Other POP combinations were identified here as modulators of AR-induced gene transactivation without affecting AR translocation. Thus, to fully evaluate the effect of environmental toxins on AR signalling, both types of assays need to be applied

A realistic mixture of Persistent Organic Pollutants (POPs) reveals possible synergism to inhibit the transactivation activities of the rat Aryl hydrocarbon Receptor (rAhR) in vitro

While organisms are exposed to mixtures of persistent organic pollutants (POPs), scientific studies usually focus on the toxicity of a single compound at a time and few have addressed the mixture effect. This study aims to determine how a realistic mixture of POPs can affect transactivation of the rat Aryl hydrocarbon Receptor (rAhR) in vitro. Luciferase reporter Dioxin responsive rat hepatoma cell lines (DR-H4IIE) were used to screen both rAhR agonistic and antagonistic activities of 29 compounds: six perfluorinated (PFAA), seven brominated (Br), and 16 chlorinated (Cl) compounds (seven polychlorinated biphenyls (PCBs) and nine organochlorine pesticides) listed as POPs under the 2001 Stockholm Convention. Only 5 (2 Cl and 3 Br) out of the 29 compounds presented rAhR agonistic activities while 16 (13 Cl and 3 Br) were rAhR antagonists. No effect was observed for PFAAs. To test possible interactions between these compounds, a mixture of these 29 POPs and six sub-mixtures (PFAA, Br, Cl, Cl + Br, Cl + PFAA and Br + PFAA), prepared based on the respective concentrations found in Scandinavian human blood with a normal daily intake, were tested for the same activities. Not surprisingly, POP mixture also displayed a rAhR antagonistic activity (IC50 = 371 ± 52 times the blood level) with the lowest effective concentration found at 75-time blood level. This level could be plausibly reached in humans after a food contamination incident or in highly exposed sub-populations. Testing the sub-mixtures showed that the Cl mixture is responsible for the antagonism of the POP mixture, contributing to 80% of the POP response. When DR-H4IIE cells were exposed to the Cl + PFAA mixture, the antagonist level was the same as the response of the POP mixture. This indicates that PFAAs are probably non-specific rAhR antagonists as they did not induce any antagonist response when tested alone. The IC50 of the Cl mixture calculated from the measured IC50 of all 13 active chlorinated compounds, using an additive model, was about the same as the measured IC50, 1.9 M and 2.3 M, respectively. This suggests that these compounds act additively in the Cl mixture. In contrast, the calculated and measured IC50 for the total POP mixture were 22 M and 43.2 M, respectively, along with non-specific rAhR antagonism of PFAA mixture, indicating a possible synergistic effect.PROTECTION AGAINST ENDOCRINE DISRUPTORS; DETECTION, MIXTURES, HEALTH EFFECTS, RISK ASSESSMENT AND COMMUNICATION

EXPOSURE TO DEFINED MIXTURES OF PERSISTENT ORGANIC POLLUTANTS (POPs) LEADS TO MITOCHONDRIAL INJURY IN THE RAT H4IIE HEPATOMA CELLS

PROTECTion against Endocrine Disruptors; Detection, mixtures, health effects, risk assessment and communication

Maternal exposure to a human relevant mixture of persistent organic pollutants reduces colorectal carcinogenesis in A/J Min/+ mice

An increased risk of developing colorectal cancer has been associated with exposure to persistent organic pollutants (POPs) and alteration in the gut bacterial community. However, there is limited understanding about the impact of maternal exposure to POPs on colorectal cancer and gut microbiota. This study characterized the influence of exposure to a human relevant mixture of POPs during gestation and lactation on colorectal cancer, intestinal metabolite composition and microbiota in the A/J Min/+ mouse model. Surprisingly, the maternal POP exposure decreased colonic tumor burden, as shown by light microscopy and histopathological evaluation, indicating a restriction of colorectal carcinogenesis. 1H nuclear magnetic resonance spectroscopy-based metabolomic analysis identified alterations in the metabolism of amino acids, lipids, glycerophospholipids and energy in intestinal tissue. In addition, 16S rRNA sequencing of gut microbiota indicated that maternal exposure modified fecal bacterial composition. In conclusion, the results showed that early-life exposure to a mixture of POPs reduced colorectal cancer initiation and promotion, possibly through modulation of the microbial and biochemical environment. Further studies should focus on the development of colorectal cancer after combined maternal and dietary exposures to environmentally relevant low-dose POP mixtures

GPs’ prescription routines and cooperation with other healthcare personnel before and after implementation of multidose drug dispensing

Beskriver en survey hvor hensikten var å undersøke fastlegers holdninger til og erfaringer med multidose, og deres erfaringer knyttet til hvordan multidose påvirker foreskriving og rutiner for kommunikasjon med hjemmeboende pasienter.Background: this study addresses GPs’ attitudes towards multidose drug dispensing before and after implementation and their perceived experience of how multidose drug dispensing affects prescription and communication routines for patients in the home care services. This study contributes to a method triangulation with two other studies on the introduction of multidose drug dispensing in Trondheim. Methods: a controlled before-and-after study carried out in Trondheim (intervention) and Tromsø (control). A questionnaire was distributed to all GPs in the two towns in 2005 with a followup questionnaire in 2008. Results: the GPs in Trondheim showed a positive attitude to multidose drug dispensing both before and after the implementation. Increased workload was reported, but still the GPs wanted the system to be continued. Most of the GPs reported a better overview of the patients’ medication and a supposed reduction in medication errors. The GPs’ prescription- and communication routines were changed only for the multidose drug users and not for the other patients in the home care services. Conclusions: the study supports the results presented in two previous publications according to GPs’ positive attitude towards multidose drug dispensing, their better overview of the patients’ medications, and improved cooperation with the pharmacy. This study adds to our understanding of prescription routines among GPs and the use of the medication module in the electronic health record