bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the effect of trigger delay on cardiac 31P MRS signals
Authors: Wampl Stefan , Körner Tito , Valkovič Ladislav , Trattnig Siegfried , Wolzt Michael , Meyerspeer Martin , Schmid Albrecht Ingo 
Published: April 2021

AbstractThe heart’s geometry and its metabolic activity vary over the cardiac cycle. The effect of these fluctuations on phosphorus (31P) magnetic resonance spectroscopy (MRS) data quality and metabolite ratios was investigated. 12 healthy volunteers were measured using a 7 T MR scanner and a cardiac 31P-1H loop coil. 31P chemical shift imaging data were acquired untriggered and at four different times during the cardiac cycle using acoustic triggering. Signals of adenosine-triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi) and 2,3-diphosphoglycerate (2,3-DPG) and their fit quality as Cramér-Rao lower bounds (CRLB) were quantified including corrections for contamination by 31P signals from blood, flip angle, saturation and total acquisition time. The myocardial filling factor was estimated from cine short axis views. The corrected signals of PCr and $$\gamma$$
γ
-ATP were higher during end-systole and lower during diastasis than in untriggered acquisitions ($$P<0.05$$

P
<
0.05

). Signal intensities of untriggered scans were between those with triggering to end-systole and diastasis. Fit quality of PCr and $$\gamma$$
γ
-ATP peaks was best during end-systole when blood contamination of ATP and Pi signals was lowest. While metabolite ratios and pH remained stable over the cardiac cycle, signal amplitudes correlated strongly with myocardial voxel filling. Triggering of cardiac 31P MRS acquisitions improves signal amplitudes and fit quality if the trigger delay is set to end-systole. We conclude that triggering to end-systole is superior to triggering to diastasis.
Zebrafish automatic monitoring system for conditioning and behavioral analysis
Authors: Barreiros Marta de Oliveira , Barbosa Felipe Gomes , Dantas Diego de Oliveira , Santos Daniel de Matos Luna dos , Ribeiro Sidarta , Santos Giselle Cutrim de Oliveira , Barros Allan Kardec 
Published: April 2021

AbstractStudies using zebrafish (Danio rerio) in neuro-behavioural research are growing. Measuring fish behavior by computational methods is one of the most efficient ways to avoid human bias in experimental analyses, extending them to various approaches. Sometimes, thorough analyses are difficult to do, as fish can behave unpredictably during an experimental strategy. However, the analyses can be implemented in an automated way, using an online strategy and video processing for a complete assessment of the zebrafish behavior, based on the detection and tracking of fish during an activity. Here, a fully automatic conditioning and detailed analysis of zebrafish behavior is presented. Microcontrolled components were used to control the delivery of visual and sound stimuli, in addition to the concise amounts of food after conditioned stimuli for adult zebrafish groups in a conventional tank. The images were captured and processed for automatic detection of the fish, and the training of the fish was done in two evaluation strategies: simple and complex. In simple conditioning, the zebrafish showed significant responses from the second attempt, learning that the conditioned stimulus was a predictor of food presentation in a specific space of the tank, where the food was dumped. When the fish were subjected to two stimuli for decision-making in the food reward, the zebrafish obtained better responses to red light stimuli in relation to vibration. The behavior change was clear in stimulated fish in relation to the control group, thus, the distances traveled and the speed were greater, while the polarization was lower in stimulated fish. This automated system allows for the conditioning and assessment of zebrafish behavior online, with greater stability in experiments, and in the analysis of the behavior of individual fish or fish schools, including learning and memory studies.
Optimal ultrasonication process time remains constant for a specific nanoemulsion size reduction system
Authors: Pratap-Singh Anubhav , Guo Yigong , Lara Ochoa Sofia , Fathordoobady Farahnaz , Singh Anika 
Published: April 2021

AbstractThis paper theorizes the existence of a constant optimum ultrasound process time for any size-reduction operation, independent of process parameters, and dependent on product parameters. We test the concept using the case of ‘ultrasonic preparation of oil-in-water nanoemulsions’ as model system. The system parameters during ultrasonication of a hempseed oil nanoemulsion was evaluated by a response surface methodology, comprising lecithin and poloxamer-188 as surfactants. Results revealed that the particle size and emulsion stability was affected significantly (p < 0.05) by all product parameters (content of hempseed oil-oil phase, lecithin and polaxamer-surfactants); but was not significantly (p > 0.05) affected by process parameter (‘ultrasonication process time’). Next, other process parameters (emulsion volume and ultrasonic amplitude) were tested using kinetic experiments. Magnitude of particle size reduction decreased with increasing ‘ultrasonication process time’ according to a first order relationship, until a minimum particle size was reached; beyond which ultrasonication no longer resulted in detectable decrease in particle size. It was found that the optimal ultrasonication process time (defined as time taken to achieve 99% of the ‘maximum possible size reduction’) was 10 min, and was roughly constant regardless of the process parameters (sample volume and ultrasonic amplitude). Finally, the existence of this constant optimal ultrasonication process time was proven for another emulsion system (olive oil and tween 80). Based on the results of these case studies, it could be theorized that a constant optimum ultrasonication process time exists for the ultrasonication-based size-reduction processes, dependent only on product parameters.
Allostery of atypical modulators at oligomeric G protein-coupled receptors
Authors: Shivnaraine Rabindra V. , Kelly Brendan , Elmslie Gwendolynne , Huang Xi-Ping , Dong Yue John , Seidenberg Margaret , Wells James W. , Ellis John 
Published: April 2021

AbstractMany G protein-coupled receptors (GPCRs) are therapeutic targets, with most drugs acting at the orthosteric site. Some GPCRs also possess allosteric sites, which have become a focus of drug discovery. In the M2muscarinic receptor, allosteric modulators regulate the binding and functional effects of orthosteric ligands through a mix of conformational changes, steric hindrance and electrostatic repulsion transmitted within and between the constituent protomers of an oligomer. Tacrine has been called an atypical modulator because it exhibits positive cooperativity, as revealed by Hill coefficients greater than 1 in its negative allosteric effect on binding and response. Radioligand binding and molecular dynamics simulations were used to probe the mechanism of that modulation in monomers and oligomers of wild-type and mutant M2receptors. Tacrine is not atypical at monomers, which indicates that its atypical effects are a property of the receptor in its oligomeric state. These results illustrate that oligomerization of the M2receptor has functional consequences.
Dissociation of disease onset, progression and sex differences from androgen receptor levels in a mouse model of amyotrophic lateral sclerosis
Authors: Tomas Doris , McLeod Victoria M. , Chiam Mathew D. F. , Wanniarachchillage Nayomi , Boon Wah C. , Turner Bradley J. 
Published: April 2021

AbstractAmyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disorder caused by loss of motor neurons. ALS incidence is skewed towards males with typically earlier age of onset and limb site of onset. The androgen receptor (AR) is the major mediator of androgen effects in the body and is present extensively throughout the central nervous system, including motor neurons. Mutations in the AR gene lead to selective lower motor neuron degeneration in male spinal bulbar muscular atrophy (SBMA) patients, emphasising the importance of AR in maintaining motor neuron health and survival. To evaluate a potential role of AR in onset and progression of ALS, we generated SOD1G93Amice with either neural AR deletion or global human AR overexpression. Using a Cre-LoxP conditional gene knockout strategy, we report that neural deletion of AR has minimal impact on the disease course in SOD1G93Amale mice. This outcome was potentially confounded by the metabolically disrupted Nestin-Cre phenotype, which likely conferred the profound lifespan extension observed in the SOD1G93Adouble transgenic male mice. In addition, overexpression of human AR produced no benefit to disease onset and progression in SOD1G93Amice. In conclusion, the disease course of SOD1G93Amice is independent of AR expression levels, implicating other mechanisms involved in mediating the sex differences in ALS. Our findings using Nestin-Cre mice, which show an inherent metabolic phenotype, led us to hypothesise that targeting hypermetabolism associated with ALS may be a more potent modulator of disease, than AR in this mouse model.
Understanding the role of aerobic fitness, spatial learning, and hippocampal subfields in adolescent males
Authors: Prathap Sandhya , Nagel Bonnie J. , Herting Megan M. 
Published: April 2021

AbstractPhysical exercise during adolescence, a critical developmental window, can facilitate neurogenesis in the dentate gyrus and astrogliogenesis in Cornu Ammonis (CA) hippocampal subfields of rats, and which have been associated with improved hippocampal dependent memory performance. Recent translational studies in humans also suggest that aerobic fitness is associated with hippocampal volume and better spatial memory during adolescence. However, associations between fitness, hippocampal subfield morphology, and learning capabilities in human adolescents remain largely unknown. Employing a translational study design in 34 adolescent males, we explored the relationship between aerobic fitness, hippocampal subfield volumes, and both spatial and verbal memory. Aerobic fitness, assessed by peak oxygen utilization on a high-intensity exercise test (VO2peak), was positively associated with the volumetric enlargement of the hippocampal head, and the CA1 head region specifically. Larger CA1 volumes were also associated with spatial learning on a Virtual Morris Water Maze task and verbal learning on the Rey Auditory Verbal Learning Test, but not recall memory. In line with previous animal work, the current findings lend support for the long-axis specialization of the hippocampus in the areas of exercise and learning during adolescence.
N-Demethylsinomenine, an active metabolite of sinomenine, attenuates chronic neuropathic and inflammatory pain in mice
Authors: Zhou Zhiyong , Qiu Nanqing , Ou Yuntao , Wei Qianqian , Tang Wenting , Zheng Mingcong , Xing Yaluan , Li Jie-Jia , Ling Yong , Li Junxu , Zhu Qing 
Published: April 2021

AbstractChronic pain is a significant public health problem that afflicts nearly 30% of the global population, but current pharmacotherapies are insufficient. Previous report indicated that N-demethylsinomenine, an active metabolite of sinomenine, is efficacious against postoperative pain. The present study investigated whether N-demethylsinomenine is effective for chronic painful conditions or whether repeated treatment alters its effect. Both chronic constriction injury (CCI) surgery and complete Freund’s adjuvant (CFA) intraplantar injection induced significant and reliable mechanical allodynia at least for 7 days. Acute treatment with N-demethylsinomenine (10–40 mg/kg, i.p.) dose-dependently attenuated the mechanical allodynia both in CCI-induced neuropathic pain and CFA-induced inflammatory pain in mice. The potency of N-demethylsinomenine for reducing CFA-induced mechanical allodynia was slightly higher than sinomenine. During the period of repeated treatment, N-demethylsinomenine maintained its anti-allodynic effect against both neuropathic and inflammatory pain without producing carry-over effect. Pretreatment with bicuculline, a selective γ-aminobutyric acid type A (GABAA) receptor antagonist, almost completely blocked the anti-allodynia of N-demethylsinomenine (40 mg/kg) both in CCI and CFA-treated mice. Our findings indicated that N-demethylsinomenine exhibits GABAA receptor-mediated anti-allodynic effects in mouse models of neuropathic and inflammatory pain, suggesting it may be a useful novel pharmacotherapy for the control of chronic pain.
Spectroscopic analysis of chia seeds
Authors: Mburu Monica , Paquet-Durand Olivier , Hitzmann Bernd , Zettel Viktoria 
Published: April 2021

AbstractChia seeds are becoming more and more popular in modern diets. In this contribution NIR and 2D-fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different regions in Kenya, 16 samples were purchased in stores in Germany and originated mostly from South America. For the purchased samples the nutritional information of the package was taken in addition to the values obtained for fat and protein, which were determined at the Hohenheim Core Facility. For the first time the NIR and fluorescence spectroscopy were used for the analysis of chia. For the spectral evaluation two different pre-processing methods were tested. Baseline correction with subsequent mean-centring lead to the best results for NIR spectra whereas SNV (standard normal variate transformation) was sufficient for the evaluation of fluorescence spectra. When combining NIR and fluorescence spectra, the fluorescence spectra were also multiplied with a factor to adjust the intensity levels. The best prediction results for the evaluation of the combined spectra were obtained for Kenyan samples with prediction errors below 0.2 g/100 g. For all other samples the absolute prediction error was 0.51 g/100 g for fat and 0.62 g/100 g for protein. It is possible to determine the amount of protein and fat of chia seeds by fluorescence and NIR spectroscopy. The combination of both methods is beneficial for the predictions. Chia seeds from Kenya had similar protein and lipid contents as South American seeds.
AntiTNF-alpha therapy normalizes levels of lipids and adipokines in psoriatic patients in the real-life settings
Authors: Olejniczak-Staruch Irmina , Narbutt Joanna , Ceryn Justyna , Skibińska Małgorzata , Bednarski Igor , Woźniacka Anna , Sieniawska Joanna , Kraska-Gacka Marzena , Ciążyńska Magdalena , Śmigielski Janusz , Noweta Marcin , Waszczykowski Michał , Owczarek Witold , Reich Adam , Lesiak Aleksandra 
Published: April 2021

AbstractStudies have shown that the levels of pro-inflammatory adipokines in patients with psoriasis are higher than in general population. The aim of the study was to investigate the influence of 36-month therapy with TNF-α inhibitors (adalimumab, etanercept, infliximab) on the levels of adipokines (resistin, adiponectin, leptin) and lipids (TG, cholesterol, LDL, HDL) in 37 psoriasis patients and 30 healthy controls. The mean serum concentrations of adiponectin in patients from adalimumab, etanercept and infliximab group were similar to control group (p > 0.05, 142.71, 164.32, 129.35 and 174.44 μg/ml respectively). Resistin levels were higher in patients (p < 0.05, 4.48, 4.53 and 3.39 ng/ml respectively) than in controls (3.05 ng/ml). Mean leptin concentrations were significantly higher (p < 0.05) in the study group than in subjects without psoriasis (428.61, 523.24, 755.27 and 154.10 pg/ml respectively). A significant decrease in the mean resistin concentration was observed under the influence of biological therapy (p < 0.05). Decrease in serum leptin level was noted in etanercept and infliximab groups (p = 0.001 and p = 0.002 respectively). Improvement in all lipidogram parameters was noted in all examined groups (p < 0.05). Results may prove that biologic therapy affects the systemic inflammation associated with psoriasis and this effect persists with long-term therapy.
Exploring diversification drivers in golden orbweavers
Authors: Turk Eva , Kralj-Fišer Simona , Kuntner Matjaž 
Published: April 2021

AbstractHeterogeneity in species diversity is driven by the dynamics of speciation and extinction, potentially influenced by organismal and environmental factors. Here, we explore macroevolutionary trends on a phylogeny of golden orbweavers (spider family Nephilidae). Our initial inference detects heterogeneity in speciation and extinction, with accelerated extinction rates in the extremely sexually size dimorphic Nephila and accelerated speciation in Herennia, a lineage defined by highly derived, arboricolous webs, and pronounced island endemism. We evaluate potential drivers of this heterogeneity that relate to organisms and their environment. Primarily, we test two continuous organismal factors for correlation with diversification in nephilids: phenotypic extremeness (female and male body length, and sexual size dimorphism as their ratio) and dispersal propensity (through range sizes as a proxy). We predict a bell-shaped relationship between factor values and speciation, with intermediate phenotypes exhibiting highest diversification rates. Analyses using SSE-class models fail to support our two predictions, suggesting that phenotypic extremeness and dispersal propensity cannot explain patterns of nephilid diversification. Furthermore, two environmental factors (tropical versus subtropical and island versus continental species distribution) indicate only marginal support for higher speciation in the tropics. Although our results may be affected by methodological limitations imposed by a relatively small phylogeny, it seems that the tested organismal and environmental factors play little to no role in nephilid diversification. In the phylogeny of golden orbweavers, the recent hypothesis of universal diversification dynamics may be the simplest explanation of macroevolutionary patterns.
Uncovering feature interdependencies in high-noise environments with stepwise lookahead decision forests
Authors: Donick Delilah , Lera Sandro Claudio 
Published: April 2021

AbstractConventionally, random forests are built from “greedy” decision trees which each consider only one split at a time during their construction. The sub-optimality of greedy implementation has been well-known, yet mainstream adoption of more sophisticated tree building algorithms has been lacking. We examine under what circumstances an implementation of less greedy decision trees actually yields outperformance. To this end, a “stepwise lookahead” variation of the random forest algorithm is presented for its ability to better uncover binary feature interdependencies. In contrast to the greedy approach, the decision trees included in this random forest algorithm, each simultaneously consider three split nodes in tiers of depth two. It is demonstrated on synthetic data and financial price time series that the lookahead version significantly outperforms the greedy one when (a) certain non-linear relationships between feature-pairs are present and (b) if the signal-to-noise ratio is particularly low. A long-short trading strategy for copper futures is then backtested by training both greedy and stepwise lookahead random forests to predict the signs of daily price returns. The resulting superior performance of the lookahead algorithm is at least partially explained by the presence of “XOR-like” relationships between long-term and short-term technical indicators. More generally, across all examined datasets, when no such relationships between features are present, performance across random forests is similar. Given its enhanced ability to understand the feature-interdependencies present in complex systems, this lookahead variation is a useful extension to the toolkit of data scientists, in particular for financial machine learning, where conditions (a) and (b) are typically met.
OptoGap is an optogenetics-enabled assay for quantification of cell–cell coupling in multicellular cardiac tissue
Authors: Boyle Patrick M. , Yu Jinzhu , Klimas Aleksandra , Williams John C. , Trayanova Natalia A. , Entcheva Emilia 
Published: April 2021

AbstractIntercellular electrical coupling is an essential means of communication between cells. It is important to obtain quantitative knowledge of such coupling between cardiomyocytes and non-excitable cells when, for example, pathological electrical coupling between myofibroblasts and cardiomyocytes yields increased arrhythmia risk or during the integration of donor (e.g., cardiac progenitor) cells with native cardiomyocytes in cell-therapy approaches. Currently, there is no direct method for assessing heterocellular coupling within multicellular tissue. Here we demonstrate experimentally and computationally a new contactless assay for electrical coupling, OptoGap, based on selective illumination of inexcitable cells that express optogenetic actuators and optical sensing of the response of coupled excitable cells (e.g., cardiomyocytes) that are light-insensitive. Cell–cell coupling is quantified by the energy required to elicit an action potential via junctional current from the light-stimulated cell(s). The proposed technique is experimentally validated against the standard indirect approach, GapFRAP, using light-sensitive cardiac fibroblasts and non-transformed cardiomyocytes in a two-dimensional setting. Its potential applicability to the complex three-dimensional setting of the native heart is corroborated by computational modelling and proper calibration. Lastly, the sensitivity of OptoGap to intrinsic cell-scale excitability is robustly characterized via computational analysis.
Mixture interactions at mammalian olfactory receptors are dependent on the cellular environment
Authors: Corey Elizabeth A. , Zolotukhin Sergei , Ache Barry W. , Ukhanov Kirill 
Published: April 2021

AbstractFunctional characterization of mammalian olfactory receptors (ORs) remains a major challenge to ultimately understanding the olfactory code. Here, we compare the responses of the mouse Olfr73 ectopically expressed in olfactory sensory neurons using AAV gene delivery in vivo and expressed in vitro in cell culture. The response dynamics and concentration-dependence of agonists for the ectopically expressed Olfr73 were similar to those reported for the endogenous Olfr73, however the antagonism previously reported between its cognate agonist and several antagonists was not replicated in vivo. Expressing the OR in vitro reproduced the antagonism reported for short odor pulses, but not for prolonged odor exposure. Our findings suggest that both the cellular environment and the stimulus dynamics shape the functionality of Olfr73 and argue that characterizing ORs in ‘native’ conditions, rather than in vitro, provides a more relevant understanding of ligand-OR interactions.