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Noise generated by motion of charge and spin provides a unique window into materials at the atomic scale. From temperature of resistors to electrons breaking into fractional quasiparticles, "listening" to the noise spectrum is a powerful way to decode underlying dynamics. Here, we use ultrasensitive superconducting quantum interference device (SQUIDs) to probe the puzzling noise in a frustrated magnet, the spin-ice compound Dy2Ti2O7 (DTO), revealing cooperative and memory effects. DTO is a topological magnet in three dimensions-characterized by emergent magnetostatics and telltale fractionalized magnetic monopole quasiparticles-whose real-time dynamical properties have been an enigma from the very beginning. We show that DTO exhibits highly anomalous noise spectra, differing significantly from the expected Brownian noise of monopole random walks, in three qualitatively different regimes: equilibrium spin ice, a "frozen" regime extending to ultralow temperatures, and a high-temperature "anomalous" paramagnet. We present several distinct mechanisms that give rise to varied colored noise spectra. In addition, we identify the structure of the local spin-flip dynamics as a crucial ingredient for any modeling. Thus, the dynamics of spin ice reflects the interplay of local dynamics with emergent topological degrees of freedom and a frustration-generated imperfectly flat energy landscape, and as such, it points to intriguing cooperative and memory effects for a broad class of magnetic materials.
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BACKGROUND: Acute and chronic postoperative pain are important healthcare problems, which can be treated with a combination of opioids and regional anaesthesia. The erector spinae plane block (ESPB) is a new regional anaesthesia technique, which might be able to reduce opioid consumption and related side effects. OBJECTIVES: To compare the analgesic effects and side effect profile of ESPB against no block, placebo block or other regional anaesthetic techniques. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Web of Science on 4 January 2021 and updated the search on 3 January 2022. SELECTION CRITERIA: Randomised controlled trials (RCTs) investigating adults undergoing surgery with general anaesthesia were included. We included ESPB in comparison with no block, placebo blocks or other regional anaesthesia techniques irrespective of language, publication year, publication status or technique of regional anaesthesia used (ultrasound, landmarks or peripheral nerve stimulator). Quasi-RCTs, cluster-RCTs, cross-over trials and studies investigating co-interventions in either arm were excluded. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed all trials for inclusion and exclusion criteria, and risk of bias (RoB), and extracted data. We assessed risk of bias using the Cochrane RoB 2 tool, and we used GRADE to rate the certainty of evidence for the primary outcomes. The primary outcomes were postoperative pain at rest at 24 hours and block-related adverse events. Secondary outcomes were postoperative pain at rest (2, 48 hours) and during activity (2, 24 and 48 hours after surgery), chronic pain after three and six months, as well as cumulative oral morphine requirements at 2, 24 and 48 hours after surgery and rates of opioid-related side effects. MAIN RESULTS: We identified 69 RCTs in the first search and included these in the systematic review. We included 64 RCTs (3973 participants) in the meta-analysis. The outcome postoperative pain was reported in 38 out of 64 studies; block-related adverse events were reported in 40 out of 64 studies. We assessed RoB as low in 44 (56%), some concerns in 24 (31%) and high in 10 (13%) of the study results. Overall, 57 studies reported one or both primary outcomes. Only one study reported results on chronic pain after surgery. In the updated literature search on 3 January 2022 we found 37 new studies and categorised these as awaiting classification. ESPB compared to no block There is probably a slight but not clinically relevant reduction in pain intensity at rest 24 hours after surgery in patients treated with ESPB compared to no block (visual analogue scale (VAS), 0 to 10 points) (mean difference (MD) -0.77 points, 95% confidence interval (CI) -1.08 to -0.46; 17 trials, 958 participants; moderate-certainty evidence). There may be no difference in block-related adverse events between the groups treated with ESPB and those receiving no block (no events in 18 trials reported, 1045 participants, low-certainty evidence). ESPB compared to placebo block ESPB probably has no effect on postoperative pain intensity at rest 24 hours after surgery compared to placebo block (MD -0.14 points, 95% CI -0.29 to 0.00; 8 trials, 499 participants; moderate-certainty evidence). There may be no difference in block-related adverse events between ESPB and placebo blocks (no events in 10 trials reported; 592 participants; low-certainty evidence). ESPB compared to other regional anaesthetic techniques Paravertebral block (PVB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to PVB (MD 0.23 points, 95% CI -0.06 to 0.52; 7 trials, 478 participants; low-certainty evidence). There is probably no difference in block-related adverse events (risk ratio (RR) 0.27, 95% CI 0.08 to 0.95; 7 trials, 522 participants; moderate-certainty evidence). Transversus abdominis plane block (TAPB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to TAPB (MD -0.16 points, 95% CI -0.46 to 0.14; 3 trials, 160 participants; low-certainty evidence). There may be no difference in block-related adverse events (RR 1.00, 95% CI 0.21 to 4.83; 4 trials, 202 participants; low-certainty evidence). Serratus anterior plane block (SAPB) The effect on postoperative pain could not be assessed because no studies reported this outcome. There may be no difference in block-related adverse events (RR 1.00, 95% CI 0.06 to 15.59; 2 trials, 110 participants; low-certainty evidence). Pectoralis plane block (PECSB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to PECSB (MD 0.24 points, 95% CI -0.11 to 0.58; 2 trials, 98 participants; low-certainty evidence). The effect on block-related adverse events could not be assessed. Quadratus lumborum block (QLB) Only one study reported on each of the primary outcomes. Intercostal nerve block (ICNB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to ICNB, but this is uncertain (MD -0.33 points, 95% CI -3.02 to 2.35; 2 trials, 131 participants; very low-certainty evidence). There may be no difference in block-related adverse events, but this is uncertain (RR 0.09, 95% CI 0.04 to 2.28; 3 trials, 181 participants; very low-certainty evidence). Epidural analgesia (EA) We are uncertain whether ESPB has an effect on postoperative pain intensity at rest 24 hours after surgery compared to EA (MD 1.20 points, 95% CI -2.52 to 4.93; 2 trials, 81 participants; very low-certainty evidence). A risk ratio for block-related adverse events was not estimable because only one study reported this outcome. AUTHORS' CONCLUSIONS: ESPB in addition to standard care probably does not improve postoperative pain intensity 24 hours after surgery compared to no block. The number of block-related adverse events following ESPB was low. Further research is required to study the possibility of extending the duration of analgesia. We identified 37 new studies in the updated search and there are three ongoing studies, suggesting possible changes to the effect estimates and the certainty of the evidence in the future.
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Analgésicos Opioides , Bloqueo Nervioso , Dolor Postoperatorio , Músculos Paraespinales , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Dolor Postoperatorio/prevención & control , Bloqueo Nervioso/métodos , Músculos Paraespinales/inervación , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/uso terapéutico , Adulto , Sesgo , Dimensión del Dolor , Anestésicos Locales/administración & dosificación , Dolor CrónicoRESUMEN
BACKGROUND: Pectoral nerve blocks (PECS block) might be an interesting new regional anaesthetic technique in patients undergoing breast surgery. OBJECTIVE: The aim of this meta-analysis was to investigate postoperative pain outcomes and adverse events of a PECS block compared with no treatment, sham treatment or other regional anaesthetic techniques in women undergoing breast surgery. DESIGN: We performed a systematic review of randomised controlled trials (RCT) with meta-analysis and risk of bias assessment. DATA SOURCES: The databases MEDLINE, CENTRAL (until December 2019) and clinicaltrials.gov were systematically searched. ELIGIBILITY CRITERIA: All RCTs investigating the efficacy and adverse events of PECS compared with sham treatment, no treatment or other regional anaesthetic techniques in women undergoing breast surgery with general anaesthesia were included. RESULTS: A total of 24 RCTs (1565 patients) were included. PECS (compared with no treatment) block might reduce pain at rest [mean difference -1.14, 95% confidence interval (CI), -2.1 to -0.18, moderate quality evidence] but we are uncertain regarding the effect on pain during movement at 24âh after surgery (mean difference -1.79, 95% CI, -3.5 to -0.08, very low-quality evidence). We are also uncertain about the effect of PECS block on pain at rest at 24âh compared with sham block (mean difference -0.83, 95% CI, -1.80 to 0.14) or compared with paravertebral block (PVB) (mean difference -0.18, 95% CI, -1.0 to 0.65), both with very low-quality evidence. PECS block may have no effect on pain on movement at 24âh after surgery compared with PVB block (mean difference -0.56, 95% CI, -1.53 to 0.41, low-quality evidence). Block-related complications were generally poorly reported. CONCLUSION: There is moderate quality evidence that PECS block compared with no treatment reduces postoperative pain intensity at rest. The observed results were less pronounced if patients received a sham block. Furthermore, PECS blocks might be equally effective as PVBs. Due to mostly low-quality or very low-quality evidence level, further research is warranted. PROTOCOL REGISTRATION: CRD42019126733.
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Neoplasias de la Mama , Bloqueo Nervioso , Nervios Torácicos , Femenino , Humanos , Bloqueo Nervioso/efectos adversos , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/epidemiología , Dolor Postoperatorio/etiología , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Temperature-swing solvent extraction (TSSE) is a cost-effective, simple, versatile, and industry-ready technology platform capable of desalinating hypersaline brines toward zero liquid discharge. In this work, we demonstrate the potential of TSSE in the effective removal of selenium oxyanions and traces of mercury with the coexistence of high contents of chloride and sulfate often encountered in flue gas desulfurization wastewater streams. We compare the rejection performance of the two common solvents broadly used for TSSE, decanoic acid (DA) and diisopropylamine (DPA), and correlate those with the solvent physicochemical properties (e.g., dielectric constant, polarity, molecular bulkiness, and hydrophobicity) and ionic properties (e.g., hydrated radii and H-bonding). The results show that TSSE can remove >99.5% of selenium oxyanions and 96%-99.6% of mercury traces coexisting with sulfate (at a sixfold Se concentration) and chloride (at a 400-fold Se concentration) in a synthetic wastewater stream. Compared to diisopropylamine, decanoic acid is more effective in rejecting ions for all cases, ranging from a simple binary system to more complex multicomponent systems with highly varied ionic concentrations. Furthermore, the H-bonding interaction with water and the hydrated radii of the oxyanions (i.e., selenate vs. selenite) along with the hindrance effects caused by the molecular bulkiness and hydrophobicity (or lipophilicity) of the solvents play important roles in the favorable rejection of TSSE. This study shows that TSSE might provide a technological solution with a high deionization potential for the industry in complying with the Environmental Protection Agency regulations for discharge streams from coal-fired power facilities.
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STUDY OBJECTIVE: Selective-serotonin-noradrenaline-reuptake inhibitors (SSNRI) might be an interesting option for postoperative pain treatment. Objective was to investigate postoperative pain outcomes of perioperative SSNRI compared to placebo or other additives in adults undergoing surgery. DESIGN: Systematic review of randomised controlled trials (RCT) with meta-analysis and GRADE assessment. SETTING: Acute and chronic postoperative pain treatment. PATIENTS: Adult patients undergoing surgery. INTERVENTIONS: Perioperative administration of SSNRI. MEASUREMENTS: Primary outcomes were postoperative acute pain at rest/during movement (measured on a scale from 0 to 10), number of patients with chronic postsurgical pain (CPSP) and with SSNRI-related adverse events. MAIN RESULTS: Fourteen RCTs (908 patients) were included. We have high-quality evidence that duloxetine has no effect on pain at rest at 2 h (MD: -0.02; 95% confidence interval (CI) -0.51 to 0.47), but probably reduces it at 48 h (MD: -1.16; 95%CI -1.78 to -0.54). There is low- and moderate-quality evidence that duloxetine has no effects on pain during movement at 2 h (MD: -0.42; 95%CI -1.53 to 0.69) and 48 h (MD: -0.91; 95% CI -2.08 to 0.26), respectively. We have very low-quality evidence that duloxetine might reduce pain at rest (MD: -0.45; 95%CI -0.74 to -0.15) and movement (MD: -1.19; 95%CI -2.32 to -0.06) after 24 h. We have low-quality evidence that duloxetine may reduce the risk of CPSP at 6 months (RR:0.35; 95%CI 0.14 to 0.90). There is moderate-quality evidence that duloxetine increases the risk of dizziness (RR:1.72; 95%CI 1.26 to 2.34). CONCLUSION: At the expense of a higher risk for dizziness, SSNRI may be effective in reducing postoperative pain between 24 and 48 h after surgery. However, the results of the meta-analyses are mostly imprecise and duloxetine might only be used in individual cases. Protocol registration: CRD42018094699.
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Inhibidores Selectivos de la Recaptación de Serotonina , Serotonina , Adulto , Clorhidrato de Duloxetina/efectos adversos , Humanos , Norepinefrina , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/prevención & control , Inhibidores Selectivos de la Recaptación de Serotonina/efectos adversosRESUMEN
We present machine learning approaches for turn prediction from the amino acid sequence. Different turn classes and types were considered based on a novel turn classification scheme. We trained an unsupervised (self-organizing map) and two kernel-based classifiers, namely the support vector machine and a probabilistic neural network. Turn versus non-turn classification was carried out for turn families containing intramolecular hydrogen bonds and three to six residues. Support vector machine classifiers yielded a Matthews correlation coefficient (mcc) of approximately 0.6 and a prediction accuracy of 80%. Probabilistic neural networks were developed for beta-turn type prediction. The method was able to distinguish between five types of beta-turns yielding mcc > 0.5 and at least 80% overall accuracy. We conclude that the proposed new turn classification is distinct and well-defined, and machine learning classifiers are suited for sequence-based turn prediction. Their potential for sequence-based prediction of turn structures is discussed.
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Inteligencia Artificial , Estructura Secundaria de Proteína , Proteínas/química , Análisis de Secuencia de Proteína/métodos , Secuencia de Aminoácidos , Simulación por Computador , Bases de Datos de Proteínas , Modelos Moleculares , Redes Neurales de la ComputaciónRESUMEN
BACKGROUND: Particle Swarm Optimization (PSO) is an established method for parameter optimization. It represents a population-based adaptive optimization technique that is influenced by several "strategy parameters". Choosing reasonable parameter values for the PSO is crucial for its convergence behavior, and depends on the optimization task. We present a method for parameter meta-optimization based on PSO and its application to neural network training. The concept of the Optimized Particle Swarm Optimization (OPSO) is to optimize the free parameters of the PSO by having swarms within a swarm. We assessed the performance of the OPSO method on a set of five artificial fitness functions and compared it to the performance of two popular PSO implementations. RESULTS: Our results indicate that PSO performance can be improved if meta-optimized parameter sets are applied. In addition, we could improve optimization speed and quality on the other PSO methods in the majority of our experiments. We applied the OPSO method to neural network training with the aim to build a quantitative model for predicting blood-brain barrier permeation of small organic molecules. On average, training time decreased by a factor of four and two in comparison to the other PSO methods, respectively. By applying the OPSO method, a prediction model showing good correlation with training-, test- and validation data was obtained. CONCLUSION: Optimizing the free parameters of the PSO method can result in performance gain. The OPSO approach yields parameter combinations improving overall optimization performance. Its conceptual simplicity makes implementing the method a straightforward task.
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Algoritmos , Proteínas Sanguíneas/metabolismo , Barrera Hematoencefálica/metabolismo , Permeabilidad de la Membrana Celular/fisiología , Modelos Biológicos , Redes Neurales de la Computación , Reconocimiento de Normas Patrones Automatizadas/métodos , Simulación por Computador , HumanosRESUMEN
Targeting signals direct proteins to their extra- or intracellular destination such as the plasma membrane or cellular organelles. Here we investigated the structure and function of exceptionally long signal peptides encompassing at least 40 amino acid residues. We discovered a two-domain organization ("NtraC model") in many long signals from vertebrate precursor proteins. Accordingly, long signal peptides may contain an N-terminal domain (N-domain) and a C-terminal domain (C-domain) with different signal or targeting capabilities, separable by a presumably turn-rich transition area (tra). Individual domain functions were probed by cellular targeting experiments with fusion proteins containing parts of the long signal peptide of human membrane protein shrew-1 and secreted alkaline phosphatase as a reporter protein. As predicted, the N-domain of the fusion protein alone was shown to act as a mitochondrial targeting signal, whereas the C-domain alone functions as an export signal. Selective disruption of the transition area in the signal peptide impairs the export efficiency of the reporter protein. Altogether, the results of cellular targeting studies provide a proof-of-principle for our NtraC model and highlight the particular functional importance of the predicted transition area, which critically affects the rate of protein export. In conclusion, the NtraC approach enables the systematic detection and prediction of cryptic targeting signals present in one coherent sequence, and provides a structurally motivated basis for decoding the functional complexity of long protein targeting signals.
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Membrana Celular/metabolismo , Proteínas de la Membrana/metabolismo , Fosfatasa Alcalina/metabolismo , Aminoácidos/química , Moléculas de Adhesión Celular/metabolismo , Línea Celular , Clonación Molecular , Densitometría , Humanos , Mitocondrias/metabolismo , Modelos Biológicos , Oligonucleótidos/química , Péptidos/química , Señales de Clasificación de Proteína , Estructura Terciaria de ProteínaRESUMEN
TLS/FUS is a nucleic acid-binding protein whose N-terminal half functions as a transcriptional activator domain in fusion oncoproteins found in human leukemias and liposarcomas. Previous reports have suggested a role for TLS/FUS in transcription and splicing processes. Here we report the association of TLS/FUS with the nuclear matrix and investigate its role in splicing. Splicing of two pre-mRNAs was inhibited in a TLS/FUS-immunodepleted extract and could only be partly restored by addition of recombinant TLS/FUS or/and SR proteins, known interaction partners of TLS/FUS. The subsequent analysis of TLS/FUS immunoprecipitates revealed that, in addition to the SR proteins SC35 and SRp75, the splicing factor PTB (hnRNPI) and the splicing coactivator SRm160 are complexed with TLS/FUS, thus explaining the inability to restore splicing completely. Coimmunolocalization confirmed the nuclear matrix association and interaction of TLS/FUS with PTB, SR proteins, and SRm160. Our results suggest that the matrix protein TLS/FUS plays a role in spliceosome assembly.