45 research outputs found

    Revealing the high-energy electronic excitations underlying the onset of high-temperature superconductivity in cuprates

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    In strongly-correlated systems the electronic properties at the Fermi energy (EF) are intertwined with those at high energy scales. One of the pivotal challenges in the field of high-temperature superconductivity (HTSC) is to understand whether and how the high energy scale physics associated with Mott-like excitations (|E-EF|>1 eV) is involved in the condensate formation. Here we show the interplay between the many-body high-energy CuO2 excitations at 1.5 and 2 eV and the onset of HTSC. This is revealed by a novel optical pump supercontinuum-probe technique, which provides access to the dynamics of the dielectric function in Y-Bi2212 over an extended energy range, after the photoinduced suppression of the superconducting pairing. These results unveil an unconventional mechanism at the base of HTSC both below and above the optimal hole concentration required to attain the maximum critical temperature (Tc)

    Quantitative Proteomic and Interaction Network Analysis of Cisplatin Resistance in HeLa Cells

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    Cisplatin along with other platinum based drugs are some of the most widely used chemotherapeutic agents. However drug resistance is a major problem for the successful chemotherapeutic treatment of cancer. Current evidence suggests that drug resistance is a multifactorial problem due to changes in the expression levels and activity of a wide number of proteins. A majority of the studies to date have quantified mRNA levels between drug resistant and drug sensitive cell lines. Unfortunately mRNA levels do not always correlate with protein expression levels due to post-transcriptional changes in protein abundance. Therefore global quantitative proteomics screens are needed to identify the protein targets that are differentially expressed in drug resistant cell lines. Here we employ a quantitative proteomics technique using stable isotope labeling with amino acids in cell culture (SILAC) coupled with mass spectrometry to quantify changes in protein levels between cisplatin resistant (HeLa/CDDP) and sensitive HeLa cells in an unbiased fashion. A total of 856 proteins were identified and quantified, with 374 displaying significantly altered expression levels between the cell lines. Expression level data was then integrated with a network of protein-protein interactions, and biological pathways to obtain a systems level view of proteome changes which occur with cisplatin resistance. Several of these proteins have been previously implicated in resistance towards platinum-based and other drugs, while many represent new potential markers or therapeutic targets

    Mitochondrial Oxidative Stress Causes Hyperphosphorylation of Tau

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    Age-related neurodegenerative disease has been mechanistically linked with mitochondrial dysfunction via damage from reactive oxygen species produced within the cell. We determined whether increased mitochondrial oxidative stress could modulate or regulate two of the key neurochemical hallmarks of Alzheimer's disease (AD): tau phosphorylation, and ß-amyloid deposition. Mice lacking superoxide dismutase 2 (SOD2) die within the first week of life, and develop a complex heterogeneous phenotype arising from mitochondrial dysfunction and oxidative stress. Treatment of these mice with catalytic antioxidants increases their lifespan and rescues the peripheral phenotypes, while uncovering central nervous system pathology. We examined sod2 null mice differentially treated with high and low doses of a catalytic antioxidant and observed striking elevations in the levels of tau phosphorylation (at Ser-396 and other phospho-epitopes of tau) in the low-dose antioxidant treated mice at AD-associated residues. This hyperphosphorylation of tau was prevented with an increased dose of the antioxidant, previously reported to be sufficient to prevent neuropathology. We then genetically combined a well-characterized mouse model of AD (Tg2576) with heterozygous sod2 knockout mice to study the interactions between mitochondrial oxidative stress and cerebral Aß load. We found that mitochondrial SOD2 deficiency exacerbates amyloid burden and significantly reduces metal levels in the brain, while increasing levels of Ser-396 phosphorylated tau. These findings mechanistically link mitochondrial oxidative stress with the pathological features of AD

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    An adapted Clavien-Dindo scoring system in trauma as a clinically meaningful non-mortality endpoint

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    BACKGROUND: There is no consensus on reporting nonmortality trauma complications in a graded manner. The Clavien-Dindo scale of complications was originally for elective surgery and requires adaptation to provide meaningful data for trauma patients. In particular, the original score does not account for those treated without surgery. We report an adapted Clavien-Dindo in trauma (ACDiT) scale and apply it to patients managed operatively and nonoperatively. METHODS: A combined prospective and retrospective international multicenter observational study was undertaken to apply the ACDiT scale to 484 trauma patients at three university teaching hospitals (Birmingham, England (n = 303); Houston, Texas (n = 113); and Glasgow, Scotland (n = 68)). These included both intensive care unit (ICU) and non-ICU-managed patients. The Clavien-Dindo scoring system was adapted for trauma patients based on consensus amongst an international collaboration of trauma specialists at these sites. Data included whether initial patients were managed operatively or nonoperatively. Complication grades were compared with hospital-free and ICU-free days as other outcome measures of patient morbidity. RESULTS: Two hundred seventeen (44.8%) of 484 patients experienced complications, of whom 61 (28.1%) of 217 died (grade V). The remainder consisted of grades I (n = 20), II (n = 60), III (n = 24), and IV (n = 52). There was a strong association between higher ACDiT grade category and lower number of hospital-free and ICU-free days (p < 0.01). Eighty-eight patients with complications did not require surgery, validating the score's usefulness in patients managed nonoperatively. CONCLUSION: The ACDiT scale can be used to grade the severity of posttrauma complications in patients managed both operatively and nonoperatively. It provides clinically meaningful data for morbidity and mortality meetings and other quality improvement exercises. LEVEL OF EVIDENCE: Prognostic, level IV
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