Superconductivity often emerges in the proximity of, or in competition with, symmetry-breaking ground states such as antiferromagnetism or charge density waves15 (CDW). A number of materials in the ...cuprate family, which includes the high transition-temperature (high-Tc) superconductors, show spin and charge density wave order.
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The application of magnetic fields to layered cuprates suppresses their high-temperature superconducting behaviour and reveals competing ground states. In widely studied underdoped YBa2Cu3O6+x ...(YBCO), the microscopic nature of field-induced electronic and structural changes at low temperatures remains unclear. Here we report an X-ray study of the high-field charge density wave (CDW) in YBCO. For hole dopings ∼0.123, we find that a field (B∼10 T) induces additional CDW correlations along the CuO chain (b-direction) only, leading to a three-dimensional (3D) ordered state along this direction at B∼15 T. The CDW signal along the a-direction is also enhanced by field, but does not develop an additional pattern of correlations. Magnetic field modifies the coupling between the CuO2 bilayers in the YBCO structure, and causes the sudden appearance of the 3D CDW order. The mirror symmetry of individual bilayers is broken by the CDW at low and high fields, allowing Fermi surface reconstruction, as recently suggested.
Telomere length has been hypothesized to be a marker of cumulative exposure to stress, and stress is an established cause of depression and anxiety disorders. The aim of this study was to examine the ...relationship between depression, anxiety and telomere length, and to assess whether this relationship is moderated by race/ethnicity, gender and/or antidepressant use. Data were from the 1999-2002 National Health and Nutrition Examination Survey. Telomere length was assessed using the quantitative PCR method of telomere length relative to standard reference DNA. Past-year major depression (MD), generalized anxiety disorder (GAD) and panic disorder (PD), as well as depressed affect and anxious affect, were assessed using the Composite International Diagnostic Inventory (N=1290). Multiple linear regression was used to assess the relationship between depression and anxiety disorders and telomere length. Among women, those with GAD or PD had shorter telomeres than those with no anxious affect (β: -0.07, P<0.01), but there was no relationship among men (β: 0.08, P>0.05). Among respondents currently taking an antidepressant, those with MD had shorter telomeres than those without (β: -0.26, P<0.05), but there was no association between MD and telomere length among those not using antidepressants (β: -0.00, P>0.05). Neither depressive nor anxiety disorders were directly associated with telomere length in young adults. There was suggestive evidence that pharmacologically treated MD is associated with shorter telomere length, likely reflecting the more severe nature of MD that has come to clinical attention.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Telomere states and cell fates Blackburn, Elizabeth H
Nature (London),
11/2000, Volume:
408, Issue:
6808
Journal Article
Peer reviewed
Telomere length has frequently been used as a means to predict the future life of cells. Here recent findings are integrated into a new, probabilistic view of the telomere to explain how and when it ...can signal not only its own fate but also that of a cell.
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Telomere length, a reliable predictor of disease pathogenesis, can be affected by genetics, chronic stress and health behaviors. Cross-sectionally, highly stressed postmenopausal women have shorter ...telomeres, but only if they are inactive. However, no studies have prospectively examined telomere length change over a short period, and if rate of attrition is affected by naturalistic factors such as stress and engagement in healthy behaviors, including diet, exercise, and sleep. Here we followed healthy women over 1 year to test if major stressors that occurred over the year predicted telomere shortening, and whether engaging in healthy behaviors during this period mitigates this effect. In 239 postmenopausal, non-smoking, disease-free women, accumulation of major life stressors across a 1-year period predicted telomere attrition over the same period-for every major life stressor that occurred during the year, there was a significantly greater decline in telomere length over the year of 35 bp (P<0.05). Yet, these effects were moderated by health behaviors (interaction B=0.19, P=0.04). Women who maintained relatively higher levels of health behaviors (1 s.d. above the mean) appeared to be protected when exposed to stress. This finding has implications for understanding malleability of telomere length, as well as expectations for possible intervention effects. This is the first study to identify predictors of telomere length change over the short period of a year.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
High temperature superconductivity in the cuprates has fascinated scientists for more than 25 years, but there is still no consensus on the pairing mechanism. Soon after the discovery of high ...temperature superconductivity, it was suggested that the cuprates have an incipient tendency towards spatial electronic order - spin and charge order. In this paper, I will review X-ray diffraction studies of charge density waves in the cuprates. These results, by a number of different groups, indicate that short-range charge correlations exist across the cuprate family, and in many cases are clearly competing with the superconductivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Chronic pain and depressive illness are debilitating disease states that are variably resistant to currently available therapeutic agents. Animal models of chronic pain are associated with activation ...of the hypothalamo‐pituitary‐adrenal (HPA) axis, upon which chronic pain acts as an inescapable stressor. Inescapable stress is also associated with ‘depressive‐like’ symptoms in experimental animals. Based on reports of the comorbidity between chronic pain and depressive illness in human patients, it is possible that these disease states are linked, via chronic stress‐induced HPA dysfunction. Here, we discuss the possible involvement of the HPA axis in the aetiology of both chronic pain and clinical depression, and suggest a strategy for the development of novel pharmacotherapies.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Telomeres are DNA-protein complexes that cap linear DNA strands, protecting DNA from damage. When telomeres critically shorten, cells become susceptible to senescence and apoptosis. Telomerase, a ...cellular ribonucleoprotein enzyme, rebuilds the length of telomeres and promotes cellular viability. Leukocyte telomeres are reportedly shortened in major depression, but telomerase activity in depression has not been previously reported. Further, there are no published reports of the effects of antidepressants on telomerase activity or on the relationship between telomerase activity and antidepressant response. Peripheral blood mononuclear cell (PBMC) telomerase activity was assessed in 20 medication-free depressed individuals and 18 controls. In total, 16 of the depressed individuals were then treated with sertraline in an open-label manner for 8 weeks, and PBMC telomerase activity was reassessed in 15 of these individuals after treatment. Pre- and post-treatment symptom severity was rated with the Hamilton Depression Rating Scale. All analyses were corrected for age and sex. Pre-treatment telomerase activity was significantly elevated in the depressed individuals compared with the controls (P=0.007) and was directly correlated with depression ratings (P<0.05) across all subjects. In the depressed group, individuals with relatively lower pre-treatment telomerase activity and with relatively greater increase in telomerase activity during treatment, showed superior antidepressant responses (P<0.05 and P<0.005, respectively). This is the first report characterizing telomerase activity in depressed individuals. PBMC telomerase activity might reflect a novel aspect of depressive pathophysiology and might represent a novel biomarker of antidepressant responsiveness.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Charge density wave (CDW) order appears throughout the underdoped high-temperature cuprate superconductors, but the underlying symmetry breaking and the origin of the CDW remain unclear. We use X-ray ...diffraction to determine the microscopic structure of the CDWs in an archetypical cuprate YBa2Cu3O6.54 at its superconducting transition temperature ∼ 60 K. We find that the CDWs in this material break the mirror symmetry of the CuO2 bilayers. The ionic displacements in the CDWs have two components, which are perpendicular and parallel to the CuO2 planes, and are out of phase with each other. The planar oxygen atoms have the largest displacements, perpendicular to the CuO2 planes. Our results allow many electronic properties of the underdoped cuprates to be understood. For instance, the CDWs will lead to local variations in the electronic structure, giving an explicit explanation of density-wave states with broken symmetry observed in scanning tunnelling microscopy and soft X-ray measurements.
Patients living with and after head and neck cancer often experience treatment-related consequences. Head and neck lymphoedema can be described as a common chronic side effect of head and neck cancer ...and recognised as a contributing factor to impairment of functional status, symptom burden and health-related quality of life. The effects of head and neck lymphoedema can limit patients' involvement in daily activities and alter their appearance, increasing symptom burden and negatively affecting health-related quality of life.
The protocol outlines the rationale and aims for the systematic review. The main aim of the systematic review is to identify and systematically synthesise the literature on the effectiveness of head and neck lymphoedema management strategies, on both function status and health-related quality of life for head and neck cancer patients.
This protocol will be conducted according to the PRISMA-P guidelines. Electronic databases will be systematically searched using MEDLINE via Ovid and PubMed, CINAHL, Cochrane Central Register of Controlled Trials and Scopus. Inclusion criteria will involve intervention studies for head and neck lymphoedema management, English language, and adult human participants following head and neck cancer. The software Covidence will be used to export, manage, and screen results. Risk of bias and quality will be assessed in included studies using the Cochrane Handbook of Systematic Reviews of Intervention risk of bias and GRADE tools. A meta-analysis will be performed if there are sufficient homogenous studies. Alternatively, a narrative synthesis will be completed on study findings.
No ethical approval is required as the study does not involve patient and public involvement. The findings of the review will be disseminated in conferences and submitted for approval to be published in a peer-reviewed journal.
CRD42022378417. (S1 Appendix).
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