bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectacular alterations in the female reproductive system during the ovarian cycle and adaptations for matrotrophy in chernetid pseudoscorpions (Pseudoscorpiones: Chernetidae)
Authors: Garbiec Arnold , Christophoryová Jana , Jędrzejowska Izabela
Published: April 2022

Pseudoscorpions are small matrotrophic chelicerates. The embryos develop in a brood sac and feed on the nutritive fluid provided by the female. It was widely accepted that the nutritive fluid is synthesized in the ovary. Recent studies have shown that in Chelifer cancroides, a representative of Cheliferidae, considered one of the most derived pseudoscorpion families, the nutritive fluid is produced not only in the ovary but also in the oviducts. Since evolution of adaptations for matrotrophy in pseudoscorpions is poorly known, we aimed to verify our hypothesis that pseudoscorpions of the family Chernetidae, closely related to Cheliferidae, share the traits of adaptations to matrotrophy in the structure and function of the female reproductive system with C. cancroides. We analysed the structure of the ovary and oviducts in five representatives of chernetids with light, confocal, and transmission electron microscopy. The results confirmed our hypothesis and provided new data which broaden our knowledge of matrotrophic pseudoscorpions. We show that in chernetids, the ovary and oviducts undergo significant alterations including their size, multistep hypertrophy and polyploidization of the epithelial cells involved in secretion of the nutritive fluid, the complex secretory activity of the epithelial cells, massive degeneration of the epithelial cells that have completed secretion, and epithelium renewal.
Synergistic efficacy of colistin and silver nanoparticles impregnated human amniotic membrane in a burn wound infected rat model
Authors: Wali Nadia , Shabbir Aroosh , Wajid Nadia , Abbas Nasir , Naqvi Syed Zeeshan Haider
Published: April 2022

Antimicrobials used to treat burn wound infections have become multidrug-resistant, thus delaying wound healing. When combined with silver nanoparticles, antibiotics create a multifaceted antibacterial mechanism of action to which bacteria are incapable of developing resistance. Similarly, the amniotic membrane has been found to lower the bacterial number. The purpose of the current study was to observe the antibacterial activity of combined topical colistin with silver nanoparticles and decellularized human amniotic membrane as a dressing in burn wounds infected with bacteria with the goal of promoting faster healing. Bacteria commonly isolated from burn wounds and the most sensitive topical antibiotic were identified. Colistin, silver nanoparticles and combined colistin with silver nanoparticles were impregnated into decellularized human amniotic membranes. These wound dressings were evaluated in third-degree multidrug-resistant bacterial infected thermal burns induced in rats. Out of a total of 708 pus samples from burn wounds, Pseudomonas aeruginosa was the most prevalent pathogen 308 (43.5%), followed by Klebsiella pneumoniae 300 (42.4%). Topical colistin was 100% sensitive for both bacteria. Overall, maximum wound contraction (p < 0.05), and increased collagen deposition (+++) with no isolation of bacteria from wound swabs were noted on day 21 for the combined colistin with silver nanoparticle-loaded human amniotic membrane dressing group. Our study concluded that the increased antimicrobial activity of the novel combination of colistin and silver nanoparticle-loaded decellularized human amniotic membrane manifested its potential as an effective burn wound dressing.
An open label randomized clinical trial of Indomethacin for mild and moderate hospitalised Covid-19 patients
Authors: Ravichandran Rajan , Mohan Surapaneni Krishna , Sukumaran Suresh Kumar , Kamaraj Devakumar , Daivasuga Sumetha Suga , Ravi Samson Oliver Abraham Samuel , Vijayaraghavalu Sivakumar , Kumar Ramarathnam Krishna
Published: April 2022

Indomethacin, a non-steroidal anti-inflammatory drug (NSAID), has been presented as a broad-spectrum antiviral agent. This randomised clinical trial in a hospital setting evaluated the efficacy and safety of this drug in RT-PCR-positive coronavirus disease 2019 (COVID-19) patients. A total of 210 RT-PCR-positive COVID-19 patients who provided consent were allotted to the control or case arm, based on block randomisation. The control arm received standard of care comprising paracetamol, ivermectin, and other adjuvant therapies. The patients in the case arm received indomethacin instead of paracetamol, with other medications retained. The primary endpoint was the development of hypoxia/desaturation with SpO2 ≤ 93, while time to become afebrile and time for cough and myalgia resolution were the secondary endpoints. The results of 210 patients were available, with 103 and 107 patients in the indomethacin and paracetamol arms, respectively. We monitored patient profiles along with everyday clinical parameters. In addition, blood chemistry at the time of admission and discharge was assessed. As no one in either of the arms required high-flow oxygen, desaturation with a SpO2level of 93 and below was the vital goal. In the indomethacin group, none of the 103 patients developed desaturation. On the other hand, 20 of the 107 patients in the paracetamol arm developed desaturation. Patients who received indomethacin also experienced more rapid symptomatic relief than those in the paracetamol arm, with most symptoms disappearing in half the time. In addition, 56 out of 107 in the paracetamol arm had fever on the seventh day, while no patient in the indomethacin group had fever. Neither arm reported any adverse event. The fourteenth-day follow-up revealed that the paracetamol arm patients had faced several discomforts; indomethacin arm patients mostly complained only of tiredness. Indomethacin is a safe and effective drug for treating patients with mild and moderate covid-19.
Hyperactivation is sufficient to release porcine sperm from immobilized oviduct glycans
Authors: Sharif Momal , Hickl Vincent , Juarez Gabriel , Di Xingjian , Kerns Karl , Sutovsky Peter , Bovin Nicolai , Miller David J.
Published: April 2022

Fertilizing sperm are retained by adhesion to specific glycans on the epithelium of the oviduct forming a reservoir before sperm are released from the reservoir so fertilization can ensue. Capacitated sperm lose affinity for the oviduct epithelium but the components of capacitation that are important for sperm release are uncertain. One important correlate of capacitation is the development of hyperactivated motility. Hyperactivation is characterized by asymmetrical flagellar beating with high beat amplitude. We tested whether the development of full-type asymmetrical motility was sufficient to release sperm from immobilized oviduct glycans. Sperm hyperactivation was induced by four different compounds, a cell-permeable cAMP analog (cBiMPS), CatSper activators (4-aminopyridine and procaine), and an endogenous steroid (progesterone). Using standard analysis (CASA) and direct visualization with high-speed video microscopy, we first confirmed that all four compounds induced hyperactivation. Subsequently, sperm were allowed to bind to immobilized oviduct glycans, and compounds or vehicle controls were added. All compounds caused sperm release from immobilized glycans, demonstrating that hyperactivation was sufficient to release sperm from oviduct cells and immobilized glycans. Pharmacological inhibition of the non-genomic progesterone receptor and CatSper diminished sperm release from oviduct glycans. Inhibition of the proteolytic activities of the ubiquitin–proteasome system (UPS), implicated in the regulation of sperm capacitation, diminished sperm release in response to all hyperactivation inducers. In summary, induction of sperm hyperactivation was sufficient to induce sperm release from immobilized oviduct glycans and release was dependent on CatSper and the UPS.
Lipid composition of the Amazonian ‘Mountain Sacha Inchis’ including Plukenetia carolis-vegae Bussmann, Paniagua & C.Téllez
Authors: Kodahl Nete , Frandsen Heidi Blok , Lütken Henrik , Petersen Iben Lykke , Paredes Andrade Nelly Judith , García-Davila Carmen , Sørensen Marten
Published: April 2022

Several Amazonian species of Plukenetia are remarkably rich sources of polyunsaturated fatty acids, in particular α-linolenic acid. The lipid composition of the large-seeded, recently described ‘Mountain Sacha Inchi’ Plukenetia carolis-vegae is reported here for the first time, and compared with Plukenetia huayllabambana, two cultivars of Plukenetia volubilis, and a newly developed hybrid between P. volubilis and P. carolis-vegae. All species and cultivars had a very high content of polyunsaturated fatty acids, 82.6–86.7% of total fatty acids, and at least 46.6% α-linolenic acid of total fatty acids. The highest content was found in P. carolis-vegae which had 57.4%. The exceptionally high α-linolenic acid content suggests that P. carolis-vegae may be an important plant-derived dietary source of this essential fatty acid and that the species has considerable potential for further domestication and commercialisation of its seeds and seed oil. A TAG analysis was carried out for the two P. volubilis cultivars, in which LLnLn and LnLL were most prevalent, and for P. huayllabambana, in which LLnLn constituted the largest fraction, followed by LnLnLn, indicating that this large-seeded species also has interesting dietary properties.
Hysteretic temperature dependence of resistance controlled by gate voltage in LaAlO3/SrTiO3 heterointerface electron system
Authors: Kwak Yongsu , Han Woojoo , Lee Joon Sung , Song Jonghyun , Kim Jinhee
Published: April 2022

For two-dimensional electron gas device applications, it is important to understand how electrical-transport properties are controlled by gate voltage. Here, we report gate voltage-controllable hysteresis in the resistance–temperature characteristics of two-dimensional electron gas at LaAlO3/SrTiO3 heterointerface. Electron channels made of the LaAlO3/SrTiO3 heterointerface showed hysteretic resistance–temperature behavior: the measured resistance was significantly higher during upward temperature sweeps in thermal cycling tests. Such hysteretic behavior was observed only after application of positive back-gate voltages below 50 K in the thermal cycle, and the magnitude of hysteresis increased with the applied back-gate voltage. To explain this gate-controlled resistance hysteresis, we propose a mechanism based on electron trapping at impurity sites, in conjunction with the strong temperature-dependent dielectric constant of the SrTiO3 substrate. Our model explains well the observed gate-controlled hysteresis of the resistance–temperature characteristics, and the mechanism should be also applicable to other SrTiO3-based oxide systems, paving the way to applications of oxide heterostructures to electronic devices.
Systematic review and network meta-analysis to compare vaccine effectiveness against porcine edema disease caused by Shiga toxin‐producing Escherichia coli
Authors: Lee Sim-In , Ntakiyisumba Eurade , Won Gayeon
Published: April 2022

The comprehensive effect size of several commercial vaccines and vaccine candidates against edema disease (ED) has not been evaluated to date. To integrate the effectiveness of ED vaccines reported so far and to compare and evaluate the posterior-effect estimates of each vaccine type with network models, we identified eligible studies (n = 12) from the electronic databases using specified search strings. Data for dichotomous outcomes (i.e., mortality and clinical symptoms) and continuous outcomes (i.e., fecal shedding and average daily gain) were extracted and analyzed. Conventional meta-analysis shows that, compared with that in non-vaccinated pigs, vaccinated animals are likely to show reduced mortality (OR = 0.07) and clinical signs of ED (OR = 0.11), and increased productivity (SMD = 0.73). Although reduced fecal shedding (SMD = − 1.29) was observed in vaccinated pigs, this could not be fully determined on insufficient grounds. In contrast to mortality and clinical symptoms, fecal shedding (I2 = 88%) and average daily gain (I2 = 85%) showed immense heterogeneity, which was attributed to the small sample size and vaccination route, respectively. According to the Bayesian network meta-analysis, the plasmid-based DNA vaccine demonstrated a better effect for all outcomes compared to other types of vaccines. However, these findings should be carefully interpreted with consideration to potential mediators, insufficient data, and inconsistent network models.
Impact of HIV-associated cognitive impairment on functional independence, frailty and quality of life in the modern era: a meta-analysis
Authors: Nweke Martins , Mshunqane Nombeko , Govender Nalini , Akinpelu Aderonke O. , Ukwuoma Maryjane
Published: April 2022

HIV-associated neurocognitive disorder (HAND) is an important sequela of HIV infection. Combined antiretroviral therapy (cART) has improved the health outcomes of many people living with HIV but has given rise to a less severe but limiting form of HAND. The study aimed to evaluate the impact of HAND on medication adherence, activities of daily living (ADL), quality of life and frailty. This systematic review adheres to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched MEDLINE, PubMed, CINAHL, Academic Search Complete, and PsycINFO online databases. Studies were included if they examined the relationship between HAND and medication adherence, ADL, quality of life and frailty, and were conducted between 1997 and 2021. We used a random-effects meta-analysis model to assess the impact of HAND on outcome variables. Forty papers, totaling 11,540 participants, were included in the narrative and quantitative syntheses. Cognitive impairment was associated with poorer medication adherence (r = 0.601, CI 0.338 to 0.776, p = 0.001, I2 = 94.66). Cognitive impairment did not influence ADL (r = 0.167, CI-0.215 to 0.505, p = 0.393) and quality of life (r = 0.244, CI 0.117 to 0.548, p = 0.182). In the cART era, HAND appears to be associated with adherence to medication, which may influence future health outcomes. In PLWHIV who are adherent to cART, cognitive impairment does not appear to interfere with ADL and quality of life.
Changes in temporal inequality of precipitation extremes over China due to anthropogenic forcings
Authors: Duan Weili , Zou Shan , Christidis Nikolaos , Schaller Nathalie , Chen Yaning , Sahu Netrananda , Li Zhi , Fang Gonghuan , Zhou Botao
Published: April 2022

Based on the Gini-coefficients, this study has presented an analysis of the impacts of anthropogenic forcing on the temporal inequality (i.e., increase in unevenness or disparity) of precipitation amounts (PRCPTOT), intensity (SDII), and extremes (R95p and RX5day) at national and regional scales (eight regions) in China. A positive anthropogenic influence on the temporal inequality is found for precipitation extremes over China, especially in southern regions during the period 1961–2005. Projections of future precipitation indices except R95p have a stepped upward trend in temporal precipitation variability with increasing anthropogenic forcing in most regions of China under SSP126, SSP370, and SSP585 scenarios. Except for Southern China (SC) and SWC2, R95p has a significant decrease in the future, and the largest decrease is up to 29.5% in Northwest China under SSP370. Results obtained from this study offer insights into temporal variability of precipitation extremes and help policy makers for managing water-related disasters.
USP39 is essential for mammalian epithelial morphogenesis through upregulation of planar cell polarity components
Authors: Kimura-Yoshida Chiharu , Mochida Kyoko , Kanno Shin-Ichiro , Matsuo Isao
Published: April 2022

Previously, we have shown that the translocation of Grainyhead-like 3 (GRHL3) transcription factor from the nucleus to the cytoplasm triggers the switch from canonical Wnt signaling for epidermal differentiation to non-canonical Wnt signaling for epithelial morphogenesis. However, the molecular mechanism that underlies the cytoplasmic localization of GRHL3 protein and that activates non-canonical Wnt signaling is not known. Here, we show that ubiquitin-specific protease 39 (USP39), a deubiquitinating enzyme, is involved in the subcellular localization of GRHL3 as a potential GRHL3-interacting protein and is necessary for epithelial morphogenesis to up-regulate expression of planar cell polarity (PCP) components. Notably, mouse Usp39-deficient embryos display early embryonic lethality due to a failure in primitive streak formation and apico-basal polarity in epiblast cells, resembling those of mutant embryos of the Prickle1 gene, a crucial PCP component. Current findings provide unique insights into how differentiation and morphogenesis are coordinated to construct three-dimensional complex structures via USP39.
Reformulation of Trivers–Willard hypothesis for parental investment
Authors: Choi Jibeom , Roh Hyungmin , Lee Sang-im , Kwon Hee-Dae , Kang Myungjoo , Jablonski Piotr G.
Published: April 2022

The Trivers-Willard hypothesis (TWH) plays a central role in understanding the optimal investment strategies to male and female offspring. Empirical studies of TWH, however, yielded conflicting results. Here, we present models to predict optimal comprehensive multi-element parental strategies composed of primary sex ratio, brood size, resource allocation among offspring, and the resultant secondary sex ratio. Our results reveal that the optimal strategy depends on sex differences in the shape of offspring fitness function rather than in fitness variance. Also, the slope of the tangent line (through the origin) to the offspring fitness function can be used to predict the preferred offspring sex. We also briefly discuss links between the model and the empirical research. This comprehensive reformulation of TWH will offer a thorough understanding of multi-element parental investment strategies beyond the classical TWH.
Evidence for postnatal neurogenesis in the human amygdala
Authors: Roeder Sebastian S. , Burkardt Petra , Rost Fabian , Rode Julian , Brusch Lutz , Coras Roland , Englund Elisabet , Håkansson Karl , Possnert Göran , Salehpour Mehran , Primetzhofer Daniel , Csiba László , Molnár Sarolta , Méhes Gábor , Tonchev Anton B. , Schwab Stefan , Bergmann Olaf , Huttner Hagen B.
Published: April 2022

The human amygdala is involved in processing of memory, decision-making, and emotional responses. Previous studies suggested that the amygdala may represent a neurogenic niche in mammals. By combining two distinct methodological approaches, lipofuscin quantification and 14C-based retrospective birth dating of neurons, along with mathematical modelling, we here explored whether postnatal neurogenesis exists in the human amygdala. We investigated post-mortem samples of twelve neurologically healthy subjects. The average rate of lipofuscin-negative neurons was 3.4%, representing a substantial proportion of cells substantially younger than the individual. Mass spectrometry analysis of genomic 14C-concentrations in amygdala neurons compared with atmospheric 14C-levels provided evidence for postnatal neuronal exchange. Mathematical modelling identified a best-fitting scenario comprising of a quiescent and a renewing neuronal population with an overall renewal rate of >2.7% per year. In conclusion, we provide evidence for postnatal neurogenesis in the human amygdala with cell turnover rates comparable to the hippocampus.
Targeting colonic macrophages improves glycemic control in high-fat diet-induced obesity
Authors: Rohm Theresa V. , Keller Lena , Bosch Angela J. T. , AlAsfoor Shefaa , Baumann Zora , Thomas Amandine , Wiedemann Sophia J. , Steiger Laura , Dalmas Elise , Wehner Josua , Rachid Leila , Mooser Catherine , Yilmaz Bahtiyar , Fernandez Trigo Nerea , Jauch Annaise J. , Wueest Stephan , Konrad Daniel , Henri Sandrine , Niess Jan H. , Hruz Petr , Ganal-Vonarburg Stephanie C. , Roux Julien , Meier Daniel T. , Cavelti-Weder Claudia
Published: April 2022

The obesity epidemic continues to worsen worldwide. However, the mechanisms initiating glucose dysregulation in obesity remain poorly understood. We assessed the role that colonic macrophage subpopulations play in glucose homeostasis in mice fed a high-fat diet (HFD). Concurrent with glucose intolerance, pro-inflammatory/monocyte-derived colonic macrophages increased in mice fed a HFD. A link between macrophage numbers and glycemia was established by pharmacological dose-dependent ablation of macrophages. In particular, colon-specific macrophage depletion by intrarectal clodronate liposomes improved glucose tolerance, insulin sensitivity, and insulin secretion capacity. Colonic macrophage activation upon HFD was characterized by an interferon response and a change in mitochondrial metabolism, which converged in mTOR as a common regulator. Colon-specific mTOR inhibition reduced pro-inflammatory macrophages and ameliorated insulin secretion capacity, similar to colon-specific macrophage depletion, but did not affect insulin sensitivity. Thus, pharmacological targeting of colonic macrophages could become a potential therapy in obesity to improve glycemic control.
Confidence modulates the decodability of scene prediction during partially-observable maze exploration in humans
Authors: Katayama Risa , Yoshida Wako , Ishii Shin
Published: April 2022

Prediction ability often involves some degree of uncertainty—a key determinant of confidence. Here, we sought to assess whether predictions are decodable in partially-observable environments where one’s state is uncertain, and whether this information is sensitive to confidence produced by such uncertainty. We used functional magnetic resonance imaging-based, partially-observable maze navigation tasks in which subjects predicted upcoming scenes and reported their confidence regarding these predictions. Using a multi-voxel pattern analysis, we successfully decoded both scene predictions and subjective confidence from activities in the localized parietal and prefrontal regions. We also assessed confidence in their beliefs about where they were in the maze. Importantly, prediction decodability varied according to subjective scene confidence in the superior parietal lobule and state confidence estimated by the behavioral model in the inferior parietal lobule. These results demonstrate that prediction in uncertain environments depends on the prefrontal-parietal network within which prediction and confidence interact.
Heterozygous variants in GATA2 contribute to DCML deficiency in mice by disrupting tandem protein binding
Authors: Hasegawa Atsushi , Hayasaka Yuki , Morita Masanobu , Takenaka Yuta , Hosaka Yuna , Hirano Ikuo , Yamamoto Masayuki , Shimizu Ritsuko
Published: April 2022

Accumulating lines of clinical evidence support the emerging hypothesis that loss-of-function mutations of GATA2 cause inherited hematopoietic diseases, including Emberger syndrome; dendritic cell, monocyte B and NK lymphoid (DCML) deficiency; and MonoMAC syndrome. Here, we show that mice heterozygous for an arginine-to-tryptophan substitution mutation in GATA2 (G2R398W/+), which was found in a patient with DCML deficiency, substantially phenocopy human DCML deficiency. Mice heterozygous for the GATA2-null mutation (G2-/+) do not show such phenotypes. The G2R398W protein possesses a decreased DNA-binding affinity but obstructs the function of coexpressed wild-type GATA2 through specific cis-regulatory regions, which contain two GATA motifs in direct-repeat arrangements. In contrast, G2R398W is innocuous in mice containing single GATA motifs. We conclude that the dominant-negative effect of mutant GATA2 on wild-type GATA2 through specific enhancer/silencer of GATA2 target genes perturbs the GATA2 transcriptional network, leading to the development of the DCML-like phenotype. The present mouse model provides an avenue for the understanding of molecular mechanisms underlying the pathogenesis of GATA2-related hematopoietic diseases.
Dynamic finite-element simulations reveal early origin of complex human birth pattern
Authors: Frémondière Pierre , Thollon Lionel , Marchal François , Fornai Cinzia , Webb Nicole M. , Haeusler Martin
Published: April 2022

Human infants are born neurologically immature, potentially owing to conflicting selection pressures between bipedal locomotion and encephalization as suggested by the obstetrical dilemma hypothesis. Australopithecines are ideal for investigating this trade-off, having a bipedally adapted pelvis, yet relatively small brains. Our finite-element birth simulations indicate that rotational birth cannot be inferred from bony morphology alone. Based on a range of pelvic reconstructions and fetal head sizes, our simulations further imply that australopithecines, like humans, gave birth to immature, secondary altricial newborns with head sizes smaller than those predicted for non-human primates of the same body size especially when soft tissue thickness is adequately approximated. We conclude that australopithecines required cooperative breeding to care for their secondary altricial infants. These prerequisites for advanced cognitive development therefore seem to have been corollary to skeletal adaptations for bipedal locomotion that preceded the appearance of the genusHomoand the increase in encephalization.
Structures of distant diphtheria toxin homologs reveal functional determinants of an evolutionarily conserved toxin scaffold
Authors: Sugiman-Marangos Seiji N. , Gill Shivneet K. , Mansfield Michael J. , Orrell Kathleen E. , Doxey Andrew C. , Melnyk Roman A.
Published: April 2022

Diphtheria toxin (DT) is the archetype for bacterial exotoxins implicated in human diseases and has played a central role in defining the field of toxinology since its discovery in 1888. Despite being one of the most extensively characterized bacterial toxins, the origins and evolutionary adaptation of DT to human hosts remain unknown. Here, we determined the first high-resolution structures of DT homologs outside of the Corynebacterium genus. DT homologs from Streptomyces albireticuli (17% identity to DT) and Seinonella peptonophila (20% identity to DT), despite showing no toxicity toward human cells, display significant structural similarities to DT sharing both the overall Y-shaped architecture of DT as well as the individual folds of each domain. Through a systematic investigation of individual domains, we show that the functional determinants of host range extend beyond an inability to bind cellular receptors; major differences in pH-induced pore-formation and cytosolic release further dictate the delivery of toxic catalytic moieties into cells, thus providing multiple mechanisms for a conserved structural fold to adapt to different hosts. Our work provides structural insights into the expanding DT family of toxins, and highlights key transitions required for host adaptation.
Tutorial: a beginner’s guide to interpreting magnetic susceptibility data with the Curie-Weiss law
Authors: Mugiraneza Sam , Hallas Alannah M.
Published: April 2022

Magnetic susceptibility measurements are often the first characterization tool that researchers turn to when beginning to assess the magnetic nature of a newly discovered material. Breakthroughs in instrumentation have made the collection of high quality magnetic susceptibility data more accessible than ever before. However, the analysis of susceptibility data remains a common challenge for newcomers to the field of magnetism. While a comprehensive treatment of the theoretical aspects of magnetism are found in numerous excellent textbooks, there is a gap at the point of practical application. We were inspired by this obstacle to put together this guide to the analysis and interpretation of magnetic susceptibility data, with an emphasis on materials that exhibit Curie-Weiss paramagnetism.
Amplitude stabilization in a synchronized nonlinear nanomechanical oscillator
Authors: Defoort Martial , Hentz Sébastien , Shaw Steven W. , Shoshani Oriel
Published: April 2022

In contrast to the well-known phenomenon of frequency stabilization in a synchronized noisy nonlinear oscillator, little is known about its amplitude stability. In this paper, we investigate experimentally and theoretically the amplitude evolution and stability of a nonlinear nanomechanical self-sustained oscillator that is synchronized with an external harmonic drive. We show that the phase difference between the tones plays a critical role on the amplitude level, and we demonstrate that in the strongly nonlinear regime, its amplitude fluctuations are reduced considerably. These findings bring to light a new facet of the synchronization phenomenon, extending its range of applications beyond the field of clock-references and suggesting a new means to enhance oscillator amplitude stability.
Terpene emissions from boreal wetlands can initiate stronger atmospheric new particle formation than boreal forests
Authors: Junninen Heikki , Ahonen Lauri , Bianchi Federico , Quéléver Lauriane , Schallhart Simon , Dada Lubna , Manninen Hanna Elina , Leino Katri , Lampilahti Janne , Buenrostro Mazon Stephany , Rantala Pekka , Räty Mari , Kontkanen Jenni , Negri Sara , Aliaga Diego , Garmash Olga , Alekseychik Pavel , Lipp Helina , Tamme Kalju , Levula Janne , Sipilä Mikko , Ehn Mikael , Worsnop Douglas , Zilitinkevich Sergej , Mammarella Ivan , Rinne Janne , Vesala Timo , Petäjä Tuukka , Kerminen Veli-Matti , Kulmala Markku
Published: April 2022

Aerosols and their interaction with clouds constitute the largest uncertainty in estimating the radiative forcing affecting the climate system. Secondary aerosol formation is responsible for a large fraction of the cloud condensation nuclei in the global atmosphere. Wetlands are important to the budgets of methane and carbon dioxide, but the potential role of wetlands in aerosol formation has not been investigated. Here we use direct atmospheric sampling at the Siikaneva wetland in Finland to investigate the emission of methane and volatile organic compounds, and subsequently formed atmospheric clusters and aerosols. We find that terpenes initiate stronger atmospheric new particle formation than is typically observed over boreal forests and that, in addition to large emissions of methane which cause a warming effect, wetlands also have a cooling effect through emissions of these terpenes. We suggest that new wetlands produced by melting permafrost need to be taken into consideration as sources of secondary aerosol particles when estimating the role of increasing wetland extent in future climate change.
Middle-lower continental crust exhumed at the distal edges of volcanic passive margins
Authors: Geoffroy Laurent , Chauvet François , Ringenbach Jean-Claude
Published: April 2022

The extent of continents in oceans is an important scientific, economic and political issue. The crustal types seaward of the necking zones of volcanic passive margins are investigated. From a set of high-quality seismic data from Namibia we discuss the nature of this crust, oceanic or continental. Here we show that over ~100 km, this crust shares few of the characteristics of oceanic crust born from accretion at a slow-spreading oceanic ridge. We alternatively suggest that the middle-lower continental crust could be exhumed and made brittle at the most distal end of volcanic passive margins. We consecutively distinguish the mechanical break-up of the continental lithosphere at volcanic passive margins, i.e., the drop in mechanical strength, from a stage of steady-state syn-magmatic extension, most probably subaerial, predating the onset of the purely magmatic oceanic crust. These findings suggest that the extent of continental material in oceans could be more significant than isolated continental blocks and microcontinents.
A comparison of respiratory particle emission rates at rest and while speaking or exercising
Authors: Orton Christopher M. , Symons Henry E. , Moseley Benjamin , Archer Justice , Watson Natalie A. , Philip Keir E. J. , Sheikh Sadiyah , Saccente-Kennedy Brian , Costello Declan , Browne William J. , Calder James D. , Bzdek Bryan R. , Hull James H. , Reid Jonathan P. , Shah Pallav L.
Published: April 2022

Background

The coronavirus disease-19 (COVID-19) pandemic led to the prohibition of group-based exercise and the cancellation of sporting events. Evaluation of respiratory aerosol emissions is necessary to quantify exercise-related transmission risk and inform mitigation strategies.

Methods

Aerosol mass emission rates are calculated from concurrent aerosol and ventilation data, enabling absolute comparison. An aerodynamic particle sizer (0.54–20 μm diameter) samples exhalate from within a cardiopulmonary exercise testing mask, at rest, while speaking and during cycle ergometer-based exercise. Exercise challenge testing is performed to replicate typical gym-based exercise and very vigorous exercise, as determined by a preceding maximally exhaustive exercise test.

Results

We present data from 25 healthy participants (13 males, 12 females; 36.4 years). The size of aerosol particles generated at rest and during exercise is similar (unimodal ~0.57–0.71 µm), whereas vocalization also generated aerosol particles of larger size (i.e. was bimodal ~0.69 and ~1.74 µm). The aerosol mass emission rate during speaking (0.092 ng s−1; minute ventilation (VE) 15.1 L min−1) and vigorous exercise (0.207 ng s−1, p = 0.726; VE 62.6 L min−1) is similar, but lower than during very vigorous exercise (0.682 ng s−1, p < 0.001; VE 113.6 L min−1).

Conclusions

Vocalisation drives greater aerosol mass emission rates, compared to breathing at rest. Aerosol mass emission rates in exercise rise with intensity. Aerosol mass emission rates during vigorous exercise are no different from speaking at a conversational level. Mitigation strategies for airborne pathogens for non-exercise-based social interactions incorporating vocalisation, may be suitable for the majority of exercise settings. However, the use of facemasks when exercising may be less effective, given the smaller size of particles produced.
Highly active ruthenium sites stabilized by modulating electron-feeding for sustainable acidic oxygen-evolution electrocatalysis
Authors: Wang Kexin , Wang Yali , Yang Bin , Li Zhongjian , Qin Xuetao , Zhang Qinghua , Lei Lecheng , Qiu Ming , Wu Gang , Hou Yang
Published: April 2022

An electron-feeding modulation strategy is developed to stabilize the highly active ruthenium site and strengthen the adsorption of the OH* intermediate toward sustainable acidic water electrolysis.
Role of polyplex charge density in lipopolyplexes
Authors: Huang Jianxiang , Song Wei , Meng Lijun , Shen Youqing , Zhou Ruhong
Published: April 2022

Molecular dynamics simulations elucidate the influence of polyplex charge density on the liposome self-assembly process at the atomic level, which provides a complementary approach to experiments for a better understanding of this promising gene therapy delivery system.
Exciton decay mechanism in DNA single strands: back-electron transfer and ultrafast base motions
Authors: Bauer Benjamin , Sharma Rahul , Chergui Majed , Oppermann Malte
Published: April 2022

Despite its key role in DNA photochemistry, the decay mechanism of excitons in stacked bases has remained difficult to resolve. Ultrafast polarization spectroscopy now reveals a back-electron transfer and ultrafast base motions in adenosine strands.
Thermodynamic equilibrium between locally excited and charge-transfer states through thermally activated charge transfer in 1-(pyren-2′-yl)-o-carborane
Authors: Ji Lei , Riese Stefan , Schmiedel Alexander , Holzapfel Marco , Fest Maximillian , Nitsch Jörn , Curchod Basile F. E. , Friedrich Alexandra , Wu Lin , Al Mamari Hamad H. , Hammer Sebastian , Pflaum Jens , Fox Mark A. , Tozer David J. , Finze Maik , Lambert Christoph , Marder Todd B.
Published: April 2022

Reversible conversion between excited-states is key to many photophysical phenomena. We studied the equilibrium between LE and CT states by time-resolved and temperature-dependent fluorescence, fs- and ns-transient absorption, and LR-TDDFT calculations.
Amino acid sequence determines the adjuvant potency of ad-tetra-peptide hydrogel
Authors: Zhang Yiming , Hu Zhiwen , Li Xinxin , Ding Yinghao , Zhang Zhenghao , Zhang Xiangyang , Zheng Wenting , Yang Zhimou
Published: April 2022

The development of novel vaccine adjuvants is essential for the production of modern vaccines against infectious agents and cancer.
Navigating complex peptide structures using macrocycle conformational maps
Authors: McTiernan Timothy J. , Diaz Diego B. , Saunders George J. , Sprang Fiona , Yudin Andrei K.
Published: April 2022

Identification of turn motifs that are stabilized by hydrogen bonds can be useful in describing the conformation of peptides. Herein, we describe “higher-order”ϕ/ψplots termed macrocycle conformational maps (MCMs) as a tool to evaluate and compare the conformations of related macrocycles.
Copper-catalyzed 1,2-Borylacylation of 1,3-Enynes: synthesis of β-Alkynyl ketones
Authors: Liu Xin-Lian , Li Lin , Lin Han-Ze , Deng Jing-Tong , Zhang Xiang-Zhi , Peng Jin-Bao
Published: April 2022

A copper catalyzed 1,2-borylacylation of 1,3-enynes with B2pin2 and acid chlorides has been developed. Highly functionalized α,α-disubstituted β-alkynyl ketones are readily prepared under mild conditions in moderate to good yields.
Coherent-interface-induced second hardening deformation of Al–Mg–Al nanolayers by molecular dynamics simulations
Authors: Lv Xue-Qi , Li Xiong-Ying , Liu Hong-Bing
Published: April 2022

In the cases of high temperatures, the Al-Mg-Al nanolayer response to increasing strain (ε < εb) with two hardening deformations due to the formation of coherent Al/Mg interfaces, which make σb and εb separately increasing by 12.3% and 20.5%.
Nitro rotation tuned dissociative electron attachment upon targeted radiosensitizer 4-substituted Z bases
Authors: Cui Xixi , Zhao Yu , Zhang Changzhe , Meng Qingtian
Published: April 2022

In this work, a set of new potential radiation sensitizers (4-substituted Z-bases: 4XZ, X = F, Cl, Br, I) are designed based on the artificial 6-amino-5-nitro-3-(1′-β-d-2′-deoxyribofuranosyl)-2(1H)-pyridone (Z), which can selectively bind to breast cancer cells.
Hydrothermal synthesis of caterpillar-like one-dimensional NiCO3 nanosheet arrays and primary lithium battery application
Authors: Cheng Cuixia , Chen Fang , Cheng Yinfang , Lai Guosong
Published: April 2022

Transition metal carbonates have shown great potential as anode materials for next-generation lithium-ion batteries (LIBs), due to their super-high capacity.
Self-assembly of Ni(ii) metallacycles (a square and a triangle) supported by tetrazine radical bridges
Authors: Wang Te , Yao Binling , Guo Zhilin , Chang Xiaoyong , Deng Yi-Fei , Zhang Yuan-Zhu
Published: April 2022

The self-assembly of Ni(ii) and 3,6-substituted tetrazine derivatives affords two Ni(ii) metallacycles (a molecular square and a molecular triangle) that feature tetrazine-based radical bridges and strong intramolecular magnetic couplings.
A boron, nitrogen-containing heterocyclic carbene (BNC) as a redox active ligand: synthesis and characterization of a lithium BNC-aurate complex
Authors: Kimura Yoshitaka , Lugo-Fuentes Leonardo I. , Saito Souta , Jimenez-Halla J. Oscar C. , Barroso-Flores Joaquín , Yamamoto Yohsuke , Nakamoto Masaaki , Shang Rong
Published: April 2022

A highly π-withdrawing boryl-substituted N-heterocyclic carbene (ClBNC) was generated at a gold(i) center, which allowed a 2e− reduction to form a 6π BNC-aurate complex, showing the redox active nature of the diboron containing carbene ligand.
Ultrasensitive self-powered photoelectrochemical detection of methane based on a coaxial integrated carbonene fiber
Authors: Zhang Chunjing , Guo Wenhao , Qin Tongtong , Qiao Xiangyu , Xiao Zhiguo , Yang Zhengpeng
Published: April 2022

A coaxial integrated fiber-shaped self-powered CNT-PVA-GAT photoelectrochemical sensor with rapid ion/electron transport and superior methane adsorption and light absorption was constructed, featuring outstanding sensing performance toward methane.
A microreactor sealing method using adhesive tape for digital bioassays
Authors: Yaginuma Hideyuki , Ohtake Kuniko , Akamatsu Takako , Noji Hiroyuki , Tabata Kazuhito V.
Published: April 2022

Microdroplet formation using adhesive tape allows for easier digital bioassays.
Recent development of organic–inorganic hybrid photocatalysts for biomass conversion into hydrogen production
Authors: Augustin Ashil , Chuaicham Chitiphon , Shanmugam Mariyappan , Vellaichamy Balakumar , Rajendran Saravanan , Hoang Tuan K. A. , Sasaki Keiko , Sekar Karthikeyan
Published: April 2022

In this review, we mainly summarize the important progress in the development of organic–inorganic hybrid photocatalysts for the production of hydrogen using biomass and its derivatives. Recent progresses and challenges are also discussed.
Preparation of yellow emissive nitrogen-doped carbon dots from o-phenylenediamine and their application in curcumin sensing
Authors: Dong Yuanyuan , Li Tianze , Bateer Buhe , Wang Huiwen , Fu Qiuyue , Zhang Fengfa
Published: April 2022

In this work, o-phenylenediamine (o-PD) and ethanol are used as raw materials, and a simple solvothermal method is used to prepare yellow emissive nitrogen-doped CDs (YNCDs) (with yellow emission λex/λem = 410/555 nm).
Unveiling the Ir single atoms as selective active species for the partial hydrogenation of butadiene by operando XAS
Authors: Liu W. , Morfin F. , Provost K. , Bahri M. , Baaziz W. , Ersen O. , Piccolo L. , Zlotea C.
Published: April 2022

Ir-single-atom catalysts for the hydrogenation of butadiene: insights from operando X-ray absorption spectroscopy.
Visible-light-mediated synthesis of α,β-diamino esters via coupling of N,N-dimethylanilines and glyoxalic oxime ethers
Authors: Singh Tavinder , Panday Prabhakar , Upreti Ganesh Chandra , Ranjan Sudhir , Gupta Raju Kumar , Singh Anand
Published: April 2022

Amine functionalization: α-aminoalkylation of glyoxalic oxime ethers employing visible-light-mediated activation of N,N-dimethylanilines.
Inorganic–organic {dz2-MIIS4}⋯π-hole stacking in reverse sandwich structures: the case of cocrystals of group 10 metal dithiocarbamates with electron-deficient arenes
Authors: Zelenkov Lev E. , Eliseeva Anastasiya A. , Baykov Sergey V. , Ivanov Daniil M. , Sumina Alina I. , Gomila Rosa M. , Frontera Antonio , Kukushkin Vadim Yu. , Bokach Nadezhda A.
Published: April 2022

The {dz2-MIIS4} (M = Ni, Pd, Pt) moieties function as integrated five-center acceptors toward a π-hole of an electron-deficient arene furnishing the reverse sandwich structures.
Selective synthesis of alkyl amines and N-vinylazoles from vinyl sulfonium salts with N-nucleophiles
Authors: Zou Liang-Hua , Liu Biao , Wang Cheng , Shao Zeyu , Zhou Junqi , Shao Andong , Wen Jian
Published: April 2022

An efficient and green approach to selective synthesis of alkyl amines and N-vinylazoles from vinyl sulfonium salts with N-nucleophiles is described.
Efficient conversion of furfural to cyclopentanol over lignin activated carbon supported Ni–Co catalyst
Authors: Guo Qi , Hou Xinglong , Xu Wei , Liu Junli
Published: April 2022

Ni3Co1/ELAC catalyst, prepared from enzymatically hydrolyzed lignin activated carbon as a carrier and a 3 : 1 ratio content of nickel and cobalt, can selectively convert furfural to cyclopentanol (CPL) in aqueous solution.
Chiral fluorescent sensor based on H8-BINOL for the high enantioselective recognition of d- and l-phenylalanine
Authors: Zhang Yafeng , Wang Huizhen , Yu Hu , Sun Xiaoxia
Published: April 2022

A triazole-modified H8-BINOL fluorescence sensor was synthesized with 95% yield, which can enantioselectively recognize l-phenylalanine without the participation of metal ions, even the enantioselective fluorescence enhancement ratio was up to 104.28.
Recent advancements in the multicomponent synthesis of heterocycles integrated with a pyrano[2,3-d]pyrimidine core
Authors: El-Khateeb Ayman Y. , Hamed Sahar E. , Elattar Khaled M.
Published: April 2022

The present review highlighted the recent developments of the multicomponent synthesis of heterocyclic compounds with pyrano[2,3-d]pyrimidine skeleton applying the diverse strategies.
The anti-Alzheimer potential of Tamarindus indica: an in vivo investigation supported by in vitro and in silico approaches
Authors: Elmaidomy Abeer H. , Abdelmohsen Usama Ramadan , Alsenani Faisal , Aly Hanan F. , Eldin Shams Shams Gamal , Younis Eman A. , Ahmed Kawkab A. , Sayed Ahmed M. , Owis Asmaa I. , Afifi Naglaa , El Amir Dalia
Published: April 2022

In vivo anti-Alzheimer's and antioxidant potential of Tamarindus indica supported by molecular docking.
Stepwise copolymerization of polybenzimidazole for a low dielectric constant and ultrahigh heat resistance
Authors: Zhong Xianzhu , Nag Aniruddha , Zhou Jiabei , Takada Kenji , Amat Yusof Fitri Adila , Mitsumata Tetsu , Oqmhula Kenji , Hongo Kenta , Maezono Ryo , Kaneko Tatsuo
Published: April 2022

A stepwise polymerization of polybenzimidazole is adopted to synthesize terpolymers with block structure, their films exhibit a low dielectric constant and ultrahigh thermal resistance.
Direct sialic acid 4-OAc substitution by nitrogen, sulfur and carbon nucleophiles with retention of stereochemistry
Authors: Bozzola Tiago , Nilsson Ulf J. , Ellervik Ulf
Published: April 2022

A direct one-step nucleophilic substitution of the 4-OAc of acetyl protected Neu5Ac is presented.
The effect of Mn and Co dual-doping on the structural, optical, dielectric and magnetic properties of ZnO nanostructures
Authors: Safeen Akif , Safeen Kashif , Shafique Muhammad , Iqbal Yousaf , Ahmed Naveed , Rauf Khan M. Abdul , Asghar Ghulam , Althubeiti Khaled , Al Otaibi Sattam , Ali Ghafar , Shah Wiqar H. , Khan Rajwali
Published: April 2022

This paper addresses the effect of Mn (2%, fixed) and Co (2, 4, and 6%, varied) substitution on the structural, optical, dielectric and magnetic responses of ZnO nanoparticles synthesized by the co-precipitation chemical route.
Development of 1,3-acetonedicarboxylate-derived glucoside amphiphiles (ACAs) for membrane protein study
Authors: Lee Ho Jin , Ehsan Muhammad , Zhang Xiang , Katsube Satoshi , Munk Chastine F. , Wang Haoqing , Ahmed Waqar , Kumar Ashwani , Byrne Bernadette , Loland Claus J. , Guan Lan , Liu Xiangyu , Chae Pil Seok
Published: April 2022

Newly developed amphiphiles, designated ACAs, are not only efficient at extracting G protein-coupled receptors from the membranes, but also conferred enhanced stability to the receptors compared to the gold standards (DDM and LMNG).
Efficient production of ethylene glycol from cellulose over Co@C catalysts combined with tungstic acid
Authors: Xin Haosheng , Wang Haiyong , Li Song , Hu Xiaohong , Wang Chenguang , Ma Longlong , Liu Qiying
Published: April 2022

The encapsulated Co@C catalyst was firstly applied for the direct production of ethylene glycol (EG) from cellulose hydrogenolysis. The multi-step reaction can be well-balanced by regulating the synergy between Co@C and tungstic acid (TA).
Matching electron transport layers with a non-halogenated and low synthetic complexity polymer:fullerene blend for efficient outdoor and indoor organic photovoltaics
Authors: Rodríguez-Martínez Xabier , Riera-Galindo Sergi , Cong Jiayan , Österberg Thomas , Campoy-Quiles Mariano , Inganäs Olle
Published: April 2022

A non-halogenated and low synthetic complexity ink formulation for the photoactive layer of organic solar cells, showing a record PCE of 7.5% in blade coated devices under 1 sun and 19.9% under indoor LED illumination.
CO2 sensing properties and mechanism of ZnMn2O4 nanotubes under air and inert conditions
Authors: Hu Jiahao , Zhang Tao , Chen Ying , Xu Pengcheng , Zheng Dan , Li Xinxin
Published: April 2022

ZnMn2O4 nanotube based CO2 sensor and sensing mechanism study.
A promising all-inorganic green-emitting YAGG:Ce phosphor-in-glass for laser lighting
Authors: Wang Luhan , Zhang Jiangdan , Wang Liansheng , Liang Yueyuan , Xu Fucai , Xu Li , Liang Xiaojuan , Chen Qing , Xiang Weidong
Published: April 2022

The modular LD was packaged with a YAGG:Ce PiG prototype with bright green light observed, which provides a new possibility for long-term and stable LDs.