1,490 research outputs found

    Reliable protein folding on non-funneled energy landscapes: the free energy reaction path

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    A theoretical framework is developed to study the dynamics of protein folding. The key insight is that the search for the native protein conformation is influenced by the rate r at which external parameters, such as temperature, chemical denaturant or pH, are adjusted to induce folding. A theory based on this insight predicts that (1) proteins with non-funneled energy landscapes can fold reliably to their native state, (2) reliable folding can occur as an equilibrium or out-of-equilibrium process, and (3) reliable folding only occurs when the rate r is below a limiting value, which can be calculated from measurements of the free energy. We test these predictions against numerical simulations of model proteins with a single energy scale.Comment: 13 pages, 9 figure

    Functionalisation of bolaamphiphiles with mononuclear bis(2,2'-bipyridyl)ruthenium(II) complexes for application in self assembled monolayers

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    A novel ruthenium(II) polypyridyl complex connected competently to a bolaamphiphile, containing amide linkages to provide rigidity via hydrogen bonding in the monolayer, has been prepared. The ruthenium(II) complexes of this ligand and of the intermediates in the synthesis were prepared by modification of the coordinated ligands, demonstrating the synthetic versatility and robustness of this family of complexes. All ruthenium complexes were characterised by electrochemical and spectroscopic techniques and were found to have similar properties to the parent complex [Ru(bipy)[3]][2][+], and remain versatile photosensitisers, with well-defined properties, despite extensive substitution of the bipy ligand

    Patterning N-type and S-type neuroblastoma cells with Pluronic F108 and ECM proteins

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    Influencing cell shape using micropatterned substrates affects cell behaviors, such as proliferation and apoptosis. Cell shape may also affect these behaviors in human neuroblastoma (NBL) cancer, but to date, no substrate design has effectively patterned multiple clinically important human NBL lines. In this study, we investigated whether Pluronic F108 was an effective antiadhesive coating for human NBL cells and whether it would localize three NBL lines to adhesive regions of tissue culture plastic or collagen I on substrate patterns. The adhesion and patterning of an S-type line, SH-EP, and two N-type lines, SH-SY5Y and IMR-32, were tested. In adhesion assays, F108 deterred NBL adhesion equally as well as two antiadhesive organofunctional silanes and far better than bovine serum albumin. Patterned stripes of F108 restricted all three human NBL lines to adhesive stripes of tissue culture plastic. We then investigated four schemes of applying collagen and F108 to different regions of a substrate. Contact with collagen obliterates the ability of F108 to deter NBL adhesion, limiting how both materials can be applied to substrates to produce high fidelity NBL patterning. This patterned substrate design should facilitate investigations of the role of cell shape in NBL cell behavior. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69159/1/32485_ftp.pd

    Histone methyltransferase PRMT6 plays an oncogenic role of in prostate cancer

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    Prostate cancer (PCa) is a major cause of morbidity and mortality. Until now the specific role of histone methyltransferases (HMTs) deregulated expression/activity in PCa is poorly understood. Herein we aimed to uncover the potential oncogenic role of PRMT6 in prostate carcinogenesis. PRMT6 overexpression was confirmed in PCa, at transcript and protein level. Stable PRMT6 knockdown in PC-3 cells attenuated malignant phenotype, increasing apoptosis and decreasing cell viability, migration and invasion. PRMT6 silencing was associated with decreased H3R2me2a levels and increased MLL and SMYD3 expression. PRMT6 silencing increased p21, p27 and CD44 and decreased MMP-9 expression and was associated with PI3K/AKT/mTOR downregulation and increased AR signaling pathway. In Sh-PRMT6 cells, AR restored expression might re-sensitized cells to androgen deprivation therapy, impacting in clinical management of castration-resistant PCa (CRPC). PRMT6 plays an oncogenic role in PCa and predicts for more clinically aggressive disease, constituting a potential target for patients with CRPC.This study was funded by research grants from European Community’s Seventh Framework Programme – Grant number FP7-HEALTH-F5-2009-241783 and from the Research Center of Portuguese Oncology Institute of Porto (CI-IPOP 4-2012). IG, FQV and JRC were supported by a FCT-Fundação para a CiĂȘncia e a Tecnologia grants (CI-IPOP-BPD/UID/DTP/00776/2013, SFRH/BD/70564/2010 and SFRH/BD/71293/2010, respectively).info:eu-repo/semantics/publishedVersio

    Does selective intraoperative music reduce pain following abdominal wall reconstruction?:A double-blind randomized controlled trial

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    Purpose: Although intraoperative music is purported to mitigate postoperative pain after some procedures, its application has never been explored in abdominal wall reconstruction (AWR). We sought to determine whether intraoperative music would decrease early postoperative pain following AWR. Methods: We conducted a placebo-controlled, patient-, surgeon-, and assessor-blinded, randomized controlled trial at a single center between June 2022 and July 2023 including 321 adult patients undergoing open AWR with retromuscular mesh. Patients received noise-canceling headphones and were randomized 1:1 to patient-selected music or silence after induction, stratified by preoperative chronic opioid use. All patients received multimodal pain control. The primary outcome was pain (NRS-11) at 24 ± 3 h. The primary outcome was analyzed by linear regression with pre-specified covariates (chronic opioid use, hernia width, operative time, myofascial release, anxiety disorder diagnosis, and preoperative STAI-6 score). Results: 178 patients were randomized to music, 164 of which were analyzed. 177 were randomized to silence, 157 of which were analyzed. At 24 ± 3 h postoperatively, there was no difference in the primary outcome of NRS-11 scores (5.18 ± 2.62 vs 5.27 ± 2.46, p = 0.75). After adjusting for prespecified covariates, the difference of NRS-11 scores at 24 ± 3 h between the music and silence groups remained insignificant (p = 0.83). There was no difference in NRS-11 or STAI-6 scores at 48 ± 3 and 72 ± 3 h, intraoperative sedation, or postoperative narcotic usage. Conclusion: For patients undergoing AWR, there was no benefit of intraoperative music over routine multimodal pain control for early postoperative pain reduction. Trial registration: ClinicalTrials.gov: NCT05374096.</p

    Stereoselective Synthesis of the Quettamine Skeleton

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    A synthesis of the quettamine skeleton 29 is described comprising ring closure of the diastereomeric phenolic 1-(α-bromobenzyl)-tetrahydroisoquinolines 27a and 27b. In both cases only one diastereomer was obtained. NOE-experiments confirm Shamma's assignments concerning the stereochemistry. - Various attemps to cleave the dithiane derivative 5 of an α-amino ketone in order to obtain the ketone 6 failed on account of the non-bonding electron pair at the N-atom. Wir beschreiben die Synthese des Quettamin-GerĂŒstes 29 durch Ringschluß der diastereomeren 1-(α-Brombenzyl)-tetrahydroisochinoline 27a and 27b. In beiden FĂ€llen resultierte nur ein Diastereomer. NOE-Messungen bestĂ€tigen Shamma's Aussagen zur Stereochemie. - Zahlreiche Versuche, das Dithian-Derivat 5 eines α-Aminoketons zum Keton 6 zu spalten, schlugen fehl wegen des nichtbindenden Elektronenpaars am Stickstoff

    Performance of a Kinetic Inductance Phonon-Mediated Detector at the NEXUS Cryogenic Facility

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    Microcalorimeters that leverage microwave kinetic inductance detectors to read out phonon signals in the particle-absorbing target, referred to as kinetic inductance phonon-mediated (KIPM) detectors, offer an attractive detector architecture to probe dark matter (DM) down to the fermionic thermal relic mass limit. A prototype KIPM detector featuring a single aluminum resonator patterned onto a 1-gram silicon substrate was operated in the NEXUS low-background facility at Fermilab for characterization and evaluation of this detector architecture's efficacy for a dark matter search. An energy calibration was performed by exposing the bare substrate to a pulsed source of 470 nm photons, resulting in a baseline resolution on the energy absorbed by the phonon sensor of 2.1±0.22.1\pm0.2 eV, a factor of two better than the current state-of-the-art, enabled by millisecond-scale quasiparticle lifetimes. However, due to the sub-percent phonon collection efficiency, the resolution on energy deposited in the substrate is limited to σE=318±28\sigma_E=318 \pm 28 eV. We further model the signal pulse shape as a function of device temperature to extract quasiparticle lifetimes, as well as the observed noise spectra, both of which impact the baseline resolution of the sensor
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