bluuebunny/crossref_metadata_2025_split huggingface dataset:
The umbilical cord mesenchymal stem cell‐derived exosomal lncRNA H19 improves osteochondral activity through miR‐29b‐3p/FoxO3 axis
Authors: Yan Litao , Liu Gejun , Wu Xing 
Published: January 2021

AbstractBackgroundOur previous study revealed that the exosomal lncRNA H19 derived from umbilical cord mesenchymal stem cells (UMSCs) plays a pivotal role in osteochondral regeneration. In this study, we investigated whether the exosomal lncRNA H19 could act as a competing endogenous RNA (ceRNA) to potentiate osteochondral activity in chondrocytes.MethodsDual‐luciferase reporter assay, RNA pull‐down, RNA immunoprecipitation (RIP), and fluorescence in situ hybridization (FISH) were carried to verify the interaction between miR‐29b‐3p and both lncRNA H19 and the target mRNA FoxO3. Chondrocytes were treated with UMSC‐derived exosomes, which highly expressing lncRNA H19 expression, followed by apoptosis, migration, senescence, and matrix secretion assessments. An in vivo SD rat cartilage defect model was carried out to explore the role and mechanism of lncRNA H19/miR‐29b‐3p.ResultsUMSCs were successfully identified, and exosomes were successfully extracted. Exosomes exhibited the ability to transfer lncRNA H19 to chondrocytes. Mechanistically, exosomal lncRNA H19 potentiated osteochondral activity by acting as a competing endogenous sponge of miR‐29b‐3p, and miR‐29b‐3p directly targeted FoxO3. Intra‐articular injection of exosomes overexpressing lncRNA H19 could promote sustained cartilage repair; however, this effect could be undermined by miR‐29b‐3p agomir.ConclusionsOur study revealed a significant role in the development of strategies against cartilage defects for UMSC‐derived exosomes that overexpress lncRNA H19. Exosomal H19 was found to promote chondrocyte migration, matrix secretion, apoptosis suppression, as well as senescence suppression, both in vitro and in vivo. The specific mechanism lies in the fact that exosomal H19 acts as a ceRNA against miR‐29b‐3p to upregulate FoxO3 in chondrocytes.
The determination of pathloss model for ultra‐high‐frequency television transmission in Onitsha, Anambra state, Nigeria
Authors: Olatoye Nurudeen Oladapo , Ekoko Erumena Constance , Sani Ogirima Mohammed , Ogungbenro Oluwaseyi 
Published: January 2021

SummaryThis research work on the determination of pathloss model for ultra‐high‐frequency (UHF) television transmission in the city of Onitsha, Anambra state, was carried out along Niksi Road, 33 area, Nkwelle‐Ezunaka to Nkwelle junction. The latitude and longitude parts of the data were measured using a software “GPS Map Mobile” installed on Tecno W3 android phone. The received power was measured at each point using “B&K precision RF signal strength analyzer 2.0‐GHz 2640.” From the analysis made using the root mean square error (RMSE), and also the graphs were plotted using MatLab package; it was discovered that the measured pathloss was interwoven with established Hata and COST‐231 Hata models by RMSE values of 4.90 and 4.74, respectively, which are within the acceptable range of 0–6 dB. These models are therefore suitable for urban center of Onitsha, and they are useful for prediction of transmission coverage in the city.
The Sertoli cell expressed gene secernin‐1 (Scrn1) is dispensable for male fertility in the mouse
Authors: Houston Brendan J. , Nagirnaja Liina , Merriner D. Jo , O'Connor Anne E. , Okuda Hidenobu , Omurtag Kenan , Smith Craig , Aston Kenneth I. , Conrad Donald F. , O'Bryan Moira K. 
Published: January 2021

AbstractBackgroundMale infertility is a prevalent clinical presentation for which there is likely a strong genetic component due to the thousands of genes required for spermatogenesis. Within this study we investigated the role of the gene Scrn1 in male fertility. Scrn1 is preferentially expressed in XY gonads during the period of sex determination and in adult Sertoli cells based on single cell RNA sequencing. We investigated the expression of Scrn1 in juvenile and adult tissues and generated a knockout mouse model to test its role in male fertility.ResultsScrn1 was expressed at all ages examined in the post‐natal testis; however, its expression peaked at postnatal days 7‐14 and SCRN1 protein was clearly localized to Sertoli cells. Scrn1 deletion was achieved via removal of exon 3, and its loss had no effect on male fertility or sex determination. Knockout mice were capable of siring litters of equal size to wild type counterparts and generated equal numbers of sperm with comparable motility and morphology characteristics.ConclusionsScrn1 was found to be dispensable for male fertility, but this study identifies SCRN1 as a novel marker of the Sertoli cell cytoplasm.
Linking land use patterns and pest outbreaks in Bt maize
Authors: St. Clair Coy R. , Gassmann Aaron J. 
Published: January 2021

AbstractWestern corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of maize in the United States and is an invasive pest in Europe. Maize is the only agricultural crop on which western corn rootworm larvae can survive and this insect requires two consecutive years of maize cultivation to complete its life cycle. Transgenic maize producing insecticidal proteins derived from the bacterium Bacillus thuringiensis (Bt) is often used to manage rootworm populations. The first Bt trait, Cry3Bb1, was introduced in 2003, but larval resistance to this toxin appeared in northeastern Iowa in 2009. Rootworm management occurs on a field‐by‐field basis, but adult rootworm may disperse among fields. It is known that growing consecutive years of Cry3Bb1 maize within a field can lead to resistance, but the relationship of the surrounding landscape to the development of resistance is unknown. Using geospatial tools and publicly available land‐use data, we examined circular areas (buffers) surrounding fields that had previously experienced high levels of rootworm injury to Cry3Bb1 maize and rootworm resistance to Cry3Bb1 maize (problem fields). We calculated the proportion of area inside each buffer planted to maize continuously for 1–9 yr, and compared these values to those for randomly selected control points throughout the state. We also calculated the proportion of the state planted to maize for at least three consecutive years for 2003 through 2018, and its relationship with the annual value of maize. We found that areas surrounding problem fields had significantly more continuous maize compared to controls, with the most continuous maize within 1.6 km of problem fields. We also found that the cultivation of continuous maize in Iowa increased significantly between 2003 and 2018, and this was correlated with average annual price of maize. We hypothesize a scenario in which continuous cultivation of Cry3Bb1 maize in local landscapes, driven in part by the increased value of maize, facilitated selection for Cry3Bb1 resistance. These results suggest that land use in areas surrounding problem fields affect the rate of resistance evolution and approaches for resistance management can be enhanced by taking a landscape‐level perspective.
Parameter redundancy in Jolly‐Seber tag loss models
Authors: Cai Wei , Yurchak Stephanie , Cole Diana J. , Cowen Laura L. E. 
Published: January 2021

AbstractCapture–recapture experiments are conducted to estimate population parameters such as population size, survival rates, and capture rates. Typically, individuals are captured and given unique tags, then recaptured over several time periods with the assumption that these tags are not lost. However, for some populations, tag loss cannot be assumed negligible. The Jolly‐Seber tag loss model is used when the no‐tag‐loss assumption is invalid. Further, the model has been extended to incorporate group heterogeneity, which allows parameters to vary by group membership. Many mark–recapture models become overparameterized resulting in the inability to independently estimate parameters. This is known as parameter redundancy.We investigate parameter redundancy using symbolic methods. Because of the complex structure of some tag loss models, the methods cannot always be applied directly. Instead, we develop a simple combination of parameters that can be used to investigate parameter redundancy in tag loss models.The incorporation of tag loss and group heterogeneity into Jolly‐Seber models does not result in further parameter redundancies. Furthermore, using hybrid methods we studied the parameter redundancy caused by data through case studies and generated tag histories with different parameter values.Smaller capture and survival rates are found to cause parameter redundancy in these models. These problems resolve when applied to large populations.
Impact of diabetes on serum biomarkers in heart failure with preserved ejection fraction: insights from the TOPCAT trial
Authors: De Marco Corrado , Claggett Brian L. , de Denus Simon , Zile Michael R. , Huynh Thao , Desai Akshay S. , Sirois Martin G. , Solomon Scott D. , Pitt Bertram , Rouleau Jean L. , Pfeffer Marc A. , O'Meara Eileen 
Published: January 2021

AbstractAimsDiabetes mellitus (DM) is common in heart failure with preserved ejection fraction (HFpEF). Patients with DM and heart failure with reduced ejection fraction have higher levels of cardiac, profibrotic, and proinflammatory biomarkers relative to non‐diabetics. Limited data are available regarding the biomarker profiles of HFpEF patients with diabetes (DM) vs. no diabetes (non‐DM) and the impact of spironolactone on these biomarkers. This study aims to address such gaps in the literature.Methods and resultsBiomarkers were measured at randomization and at 12 months in 248 patients enrolled in Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist's North American cohort. At baseline, DM patients had significantly lower estimated glomerular filtration rate and higher high‐sensitivity C‐reactive protein, pro‐collagen type III amino‐terminal peptide, tissue inhibitor of metalloproteinase 1 (TIMP‐1), and galectin‐3 levels than those without diabetes. There was a significantly larger 12 month increase in levels of high‐sensitivity troponin T (hs‐TnT), a marker of myocyte death, in DM patients. Elevated pro‐collagen type III amino‐terminal peptide and galectin‐3 levels were associated with an increased risk of the primary outcome (cardiovascular mortality, aborted cardiac arrest, or heart failure hospitalization) in DM patients, but not in those without diabetes. A statistically significant interaction between spironolactone and diabetes status was observed for hs‐TnT and for TIMP‐1, with greater biomarker reductions among those with diabetes treated with spironolactone.ConclusionsThe presence of diabetes is associated with higher levels of cardiac, profibrotic, and proinflammatory biomarkers in HFpEF. Spironolactone appears to alter the determinants of extracellular matrix remodelling in an anti‐fibrotic fashion in patients with diabetes, reflected by changes in hs‐TnT and TIMP‐1 levels over time.
Photoinduced Decarboxylative Radical Addition Reactions for Late Stage Functionalization of Peptide Substrates
Authors: Fernandez‐Rodriguez Patricia , Legros Fabien , Maier Thomas , Weber Angelika , Méndez María , Derdau Volker , Hessler Gerhard , Kurz Michael , Villar‐Garea Ana , Ruf Sven 
Published: January 2021

AbstractPhotoredox chemistry has greatly stimulated the application of radical based transformations in medicinal chemistry and early drug discovery in recent years. Carboxylate groups have been identified as traceless leaving groups that can be converted into radical intermediates capable of undergoing 1,4‐conjugate addition reactions to Michael acceptors. Herein, we show the successful C‐terminal derivatization of small peptide substrates by using this methodology in a parallel synthesis setting. Finally, we outline a general strategy for the γ‐homologation of several drugs derived from α‐amino acids in a late stage functionalization (LSF) approach.
Electrostatics Favor PNA : DNA Stability over Stereochemistry in Pyrrolidine‐Based Cationic Dual‐Backbone PNA Analogues
Authors: Sharma Ashwani , More Shahaji H. , Ganesh Krishna N. 
Published: January 2021

AbstractModifications to the peptide nucleic acid (PNA) backbone has been well known to alter the thermodynamical parameters of PNA : DNA complexes to broaden their utility for different applications. Electrostatic interactions between a modified PNA having a positively charged backbone and the negatively charged DNA has been shown to enhance thermal stabilities of PNA : DNA complexes at various instances. On the other hand, chiral introduction in PNA backbone leads to stereochemical preference that affects binding properties. However, the interplay between electrostatics and stereochemistry has not been systematically studied so far. Herein, we report the synthesis and biophysical characterization of cationic PNA named dapPNA, first of its kind, having a dual PNA backbone constituting of a pyrrolidine ring having a β‐substitution. One of the aims of this study was to investigate the role of electrostatics over stereochemical preferences. The results show that electrostatic attraction between cationic dapPNA and negatively charged DNA overcomes the unfavorable stereochemical effects and enhances stability of PNA : DNA complexes. Moreover, two different PNA backbones derived from a single PNA monomer expands the repertoire of pyrrolidine based PNA analogues.
The Chemistry of High‐Oxidation State Securinega Alkaloids
Authors: Kang Gyumin , Park Sangbin , Han Sunkyu 
Published: January 2021

AbstractSecurinega alkaloids have fascinated the chemical community for over six decades. Among these intriguing secondary metabolites, there are members that are biosynthesized via oxidation(s) of the basic tetracyclic core of securinega natural products. These oxidation processes result in a sub‐family of natural products with intriguing structural variations. We have grouped them as “high‐oxidation state” securinega alkaloids. In this minireview, we, for the first time, categorize high‐oxidation state securinega alkaloids into five groups based on their structural phenotype. We then describe all known syntheses of high‐oxidation state securinega alkaloids based on our classification. Plausible biosynthetic origins of securinega alkaloids in each group are described. Notable interplays between chemical synthesis and biosynthesis within this family of natural products are depicted. The updated comprehensive investigation of the chemistry of high‐oxidation state securinega alkaloids provides us with an outlook on remaining key challenges related to these fascinating natural products.
Design of Copper Microfabricated Potentiometric Sensor for in‐line Monitoring of Neostigmine Degradation Kinetics
Authors: El‐Sayed Ghada M. , El Mously Dina A. , Mostafa Nadia M. , Hassan Nagiba Y. , Mahmoud Amr M. 
Published: January 2021

AbstractThe quality of pharmaceutical products is critical for human health. Drug development requires tools to assess the presence of degradation products and contaminants during the manufacturing and storage processes. Accelerated stress degradation and kinetic studies play a vital role in predicting final product stability. This work describes the design of potentiometric sensor based on copper microfabricated electrodes for in‐line tracking the degradation kinetics of neostigmine. The proposed electrochemical technique provides a continuous profile for the hydrolysis of NEO under different temperatures and pH. The hydrolysis activation energy was found to be 18.88 kcal mol−1 which was aligned with the reported hydrolysable ester values. Consequently, the kinetic data analysis is crucial to predict the optimum analysis and storage conditions.
Correlating Quantitative Measurements of Radical Production by Photocatalytic TiO2 with Daphnia magna Toxicity
Authors: Coral Jason A. , Kitchens Christopher L. , Brumaghim Julia L. , Klaine Stephen J. 
Published: January 2021

Abstract
Increased use of titanium dioxide (TiO2) nanoparticles (NPs) in domestic and industrial applications has increased the risk for adverse environmental outcomes based on an elevated likelihood of organism exposure. Anatase TiO2 NP exposure to ultraviolet A (UV-A) radiation in aquatic environments generates radical oxygen species (ROS), which may ultimately be responsible for increased organism toxicity. We have identified and measured the 2 most relevant ROS species, hydroxyl and superoxide radicals, and described that ROS can be modeled using the highly reactive hydroxyl radical to provide an upper bound for toxicity. The TiO2 NPs were co-exposed to increasing natural organic matter (NOM) amounts (measured as concentration of dissolved organic carbon [DOC]) and simulated-sunlight UV-A intensities. Radical production rate was determined using fluorescence spectroscopy and was positively correlated with increases in TiO2 concentration and UV-A intensity, and negatively correlated with increased DOC concentration. Daphnia magna toxicity was also found to decrease with NOM addition, which is attributed to the decreased radical production rate with increased DOC concentrations. We demonstrate that the rate of ROS production from simulated-sunlight–irradiated TiO2 NPs can be quantified using relatively simple fluorescent techniques. We show that toxicity to TiO2 NP varies greatly with conditions, and that concentration alone is a poor predictor of toxicity. Describing toxicity/hydroxyl radical measurement may be a more accurate way to describe overall risk. We provide a framework for a simple model to describe toxicity/hydroxyl radical. These conclusions demonstrate the importance of considering exposure conditions as a means of risk management during TiO2 NP toxicity testing, waste management, and regulatory decisions. Environ Toxicol Chem 2021;40:1322–1334. © 2021 SETAC
Perceptions of Ecosystem-Based Fisheries Management Among State Natural Resource Agency Scientists in the Northeastern United States
Authors: Safiq Alexandrea , Free Christopher M , Caracappa Joseph , Valenti Jessica L , Jensen Olaf 
Published: January 2021

Abstract
Ecosystem-based fisheries management (EBFM) is an application of ecosystem-based management in which abiotic, biotic, and socio-economic interactions are considered when managing fisheries. The primary objectives of this study were: (1) to understand how state fishery scientists define EBFM; (2) to identify the perceived implementation of EBFM components within state agencies; and (3) to identify potential barriers in implementing EBFM at the state level. The uniformity across inclusion responses indicated that there was a shared definition of EBFM among state fishery scientists. The most frequently implemented component was engaging stakeholders, and the least frequently implemented component was accounting for uncertainty in ecosystems. Overall, the most frequently cited barriers were stakeholder engagement in the New England region and regulatory barriers in the mid-Atlantic region. These findings can help identify where potential human and fiscal resources should be allocated for successful implementation of EBFM at the state level.
Soil use in pre‐Hispanic and historical crop fields in the Guatacondo Ravine, northern Chile (2400 years BP): A geoarchaeological and paleobotanic approach
Authors: Segura Camila , Vidal Ale , Maldonado Antonio , Uribe Mauricio 
Published: January 2021

AbstractIn one of the most arid places on Earth, the Atacama Desert in northern Chile (18–21° S), pre‐Hispanic cultures developed different types of tillage and irrigation systems in the Guatacondo Ravine. Their agrarian production, based on a summer precipitation regime, enabled the formative villages of Ramaditas (2300–2600 years BP) and Guatacondo (2400–2800 years BP) to emerge, along with seasonal agriculture. Despite the insight gained into their agricultural technology, we know very little about how this type of soil management affected the soils' plant nutrient status. Thus, our main objective was to determine if the different tillage systems affected the soils' properties. We analyzed the soils and the pollen composition of different tillage systems and carried out direct radiocarbon dating (14C) of sediments. The soils' chemical properties (total nitrogen, phosphorus, and organic carbon contents) indicate greater nutrient retention in the square bed system, associated with a higher silt content and the use of organic fertilizers. Pollen analyses show the presence of crop, weed, and riparian species. In conclusion, the analysis of ancient soils gives us valuable information about the innovations and changes implemented in ancient times in the Guatacondo Ravine.
Disruption of circadian timing increases synaptic inhibition and reduces cholinergic responsiveness in the dentate gyrus
Authors: McMartin Laura , Kiraly Marianna , Heller H. Craig , Madison Daniel V. , Ruby Norman F. 
Published: January 2021

AbstractWe investigated synaptic mechanisms in the hippocampus that could explain how loss of circadian timing leads to impairments in spatial and recognition memory. Experiments were performed in hippocampal slices from Siberian hamsters (Phodopus sungorus) because, unlike mice and rats, their circadian rhythms are easily eliminated without modifications to their genome and without surgical manipulations, thereby leaving neuronal circuits intact. Recordings of excitatory postsynaptic field potentials and population spikes in area CA1 and dentate gyrus granule cells revealed no effect of circadian arrhythmia on basic functions of synaptic circuitry, including long‐term potentiation. However, dentate granule cells from circadian‐arrhythmic animals maintained a more depolarized resting membrane potential than cells from circadian‐intact animals; a significantly greater proportion of these cells depolarized in response to the cholinergic agonist carbachol (10 μM), and did so by increasing their membrane potential three‐fold greater than cells from the control (entrained) group. Dentate granule cells from arrhythmic animals also exhibited higher levels of tonic inhibition, as measured by the frequency of spontaneous inhibitory postsynaptic potentials. Carbachol also decreased stimulus‐evoked synaptic excitation in dentate granule cells from both intact and arrhythmic animals as expected, but reduced stimulus‐evoked synaptic inhibition only in cells from control hamsters. These findings show that loss of circadian timing is accompanied by greater tonic inhibition, and increased synaptic inhibition in response to muscarinic receptor activation in dentate granule cells. Increased inhibition would likely attenuate excitation in dentate‐CA3 microcircuits, which in turn might explain the spatial memory deficits previously observed in circadian‐arrhythmic hamsters.