bluuebunny/crossref_metadata_2025 huggingface dataset:
PCR diagnostics for rapid detection of fungi associated with black root rot of strawberries
Authors: Löhrer Marco , Vogel Lara , Petrescu Dita Singer Sarah , Erwes Stefanie , Heupel Monika , Schaffrath Ulrich
Published: April 2022

Black root rot is a disease of the strawberry with increasing importance for Germany. Until the early years of the twenty-first century, very different pathogens, including fungi and nematodes, were thought to cause this disease. However, based on substantial research between 2007 and 2014 at the fruit-growing center Jork (Esteburg, Germany) fungi with Cylindrocarpon-like anamorphs, i.e., Dactylonectria torresensis and Ilyonectria spp. were identified as causal agents. Both fungi are soil-borne pathogens and able to infect young strawberry plants in nurseries. Therefore, it is crucial to test plants prior to further propagation for the presence of these organisms. Although speed of diagnosis is a well-known and important factor, until today only time-consuming microbiological tests are available. To improve the situation, we aimed at developing a rapid, PCR-based, assay for the detection of fungi associated with black root rot. Most challenging was the design of specific primers that recognize the pathogen(s) in question while being unspecific for other fungi and Oomycetes routinely found on strawberries. Here, we report on a pair of primers that fulfill these rigorous criteria and present data on their specificity and sensitivity. A concentration of as low as 1.25 pg µl−1 template DNA from target pathogens could be detected in infected tissue. Significantly, the same primers were successfully used in standard and quantitative PCR assays. Based on our results, diagnostic laboratories are now enabled to rapidly survey lots of strawberry plants and provide growers with precise information on the presence of fungi associated with black root rot even in asymptomatic plants.
High-Frequency Vibration Tests for Cement Concrete for Machine Tools (300–500 Hz)
Authors: Brecher C. , Kiesewetter-Marko C. , Kalthoff M. , Neus S.
Published: April 2022

Purpose

Occasionally, cement concrete is used in the machine tool industry to reduce costs and improve the dynamic behavior of the machine. Due to a lack of information on the material behavior of cement concrete under dynamic loads with high frequencies, a test bench has been developed based on the principle of resonance at WZL. This paper presents the further development of the test bench to improve the testing and the evaluation of the results. Furthermore, the execution of dynamic tests with alternating loads in a high-frequency range of specimens of ultra-high-performance concrete (UHPC) is described. The aim of the described tests is to investigate the influence of frequency range and the autoclaving post treatment on the limiting load of UHPC specimens.

Methods

To be able to react in situ to a change in the natural frequency of the system and thus to ensure a consistent level of dynamic loading, a control and regulation method was developed and implemented into the test bench. Additionally, dynamic tests of UHPC specimens with different load levels and frequency ranges are executed on the test bench also using the automatic test regulation. The UHPC specimens were autoclaved after production to achieve high material properties and to anticipate shrinkage deformation. The amplitudes of load applied to the specimens were determined as function of the previously determined static tensile strength. The amplitudes of load tested were set between 37 and 50% of the static centric tensile strength. The frequencies tested were at about 326 Hz respectively 475 Hz and therefore lie in a high-frequency range.

Results

First tests with the new developed automatic test regulation show, that a consistent level of dynamic load can be achieved. The dynamic long-term tests of autoclaved UHPC specimens with different load levels and frequency ranges show, that the limiting load for alternating forces on UHPC in a high-frequency range lies in the area of 40% of the static centric tensile strength. These results confirm the conclusions of other researchers for the lower-frequency ranges and expand the conclusions to the examined frequency ranges. With the test set-up and the automatic test regulation, fatigue tests can be performed 40 to 50 times faster than with conventional test set-ups (with frequencies at about 10 Hz as a reference).

Conclusion

By implementing an automatic adaption of the actual resonance frequency of the system, a consistent level of dynamic load on the specimens could be achieved. Furthermore, it can be stated, that the limiting load for alternating forces on UHPC at high frequencies is mostly unaffected by the actual range of high frequencies or the follow-up treatment of the specimens. Future research should issue a more detailed localization of the limiting force as well as other post-treatments and a transfer to the application of UHPC in real parts of machine tools.
Medicine and the critique of war: military psychiatry, social classification and the malingering patient in colonial India
Authors: Khan Sanaullah
Published: April 2022

The treatment of injured Indian soldiers in Britain during WWI deployed particular ways of recording injuries and using them to make judgments about loyalty to the Imperial Army by assessing the soldier’s ability to malinger. This was possible by using personal correspondences between soldiers and their families for ethnographic ends ie. to determine susceptibility to develop mental illness through a soldier’s ethnic background and whether he was from the so-called ‘martial races’ or not. This classificatory knowledge as well as the suspicion towards exaggerated symptoms was also inherited by Indian psychiatry after partition. However, while these psychiatrists reproduced some colonial biases about susceptibility of illness, they were much more receptive to considering the social experience of patients including their kinship relations at home and in the military. By the end of WWII, symptoms came to be regarded as signs of recovery and readjustment to social relations to make a case for the lasting impacts of war on the soldier’s mental and physical health.
TEXTUAL NOTES ON ACHILLES TATIUS
Authors: Kanavou Nikoletta
Published: April 2022

This paper contributes to the textual criticism of Achilles Tatius’ novel Leucippe and Clitophon by proposing a number of alterations to the text of the most recent edition of the complete novel (Les Belles Lettres) (Paris, 1991).
Asymptotic identities for additive convolutions of sums of divisors
Authors: OLIVER ROBERT J. LEMKE , SHRESTHA SUNROSE T. , THORNE FRANK
Published: April 2022

In a 1916 paper, Ramanujan studied the additive convolution
$S_{a, b}(n)$
of sum-of-divisors functions
$\sigma_a(n)$
and
$\sigma_b(n)$
, and proved an asymptotic formula for it when a and b are positive odd integers. He also conjectured that his asymptotic formula should hold for all positive real a and b. Ramanujan’s conjecture was subsequently proved by Ingham, and then by Halberstam with a power saving error term.

In this paper, we give a new proof of Ramanujan’s conjecture that obtains lower order terms in the asymptotics for most ranges of the parameters. We also describe a connection to a counting problem in geometric topology that was studied in the second author’s thesis and which served as our initial motivation in studying this sum.
Answer Set Planning: A Survey
Authors: CAO TRAN SON , PONTELLI ENRICO , BALDUCCINI MARCELLO , SCHAUB TORSTEN
Published: April 2022

Answer Set Planningrefers to the use ofAnswer Set Programming (ASP)to computeplans, that is, solutions to planning problems, that transform a given state of the world to another state. The development of efficient and scalable answer set solvers has provided a significant boost to the development of ASP-based planning systems. This paper surveys the progress made during the last two and a half decades in the area of answer set planning, from its foundations to its use in challenging planning domains. The survey explores the advantages and disadvantages of answer set planning. It also discusses typical applications of answer set planning and presents a set of challenges for future research.
Das exemplarische Prinzip in der generalistischen Pflegeausbildung
Authors: Hamar Christoph , Hartmann Wiebke
Published: April 2022

Zusammenfassung. Die generalistische Pflegeausbildung konfrontiert Lehrende mit einer Verschärfung der „Stofffüllenproblematik“: Sowohl die zu vermittelnden Inhalte als auch das Quantum an pflegerischem Wissen wachsen exponentiell an (Chinn & Kramer, 2018; Schneider et al., 2018), während das zur Verfügung stehende Zeitkontingent unverändert bleibt (2100 Stunden). Didaktisch bietet sich hier die Umsetzung des exemplarischen Prinzips an (Wagenschein, 1959a), dessen Charakteristika im Folgenden beschrieben werden.
Unterrichtliche Umsetzung des exemplarischen Prinzips
Authors: Hamar Christoph , Hartmann Wiebke , Schneider Kordula
Published: April 2022

Zusammenfassung. Die Umsetzung des exemplarischen Prinzips in der generalistischen Pflegeausbildung wird von den Rahmenlehrplänen für den theoretischen und praktischen Unterricht explizit gefordert (Fachkommission, 2020a, 2020b). Gleichzeitig stellt sie ein probates Mittel zur Reduktion der Stofffülle dar, ohne dabei zu Abstrichen bei der Initiierung von Bildungsprozessen zu führen (s. Hamar & Hartmann, diese Ausgabe). Damit die inhaltliche Bestimmung des Wesentlichen und die didaktische Auswahl eines Exempels systematisch erfolgen kann, wird hier ein pragmatischer Handlungsleitfaden für Lehrende vorgestellt.
Power Pack
Authors: Zegelin Angelika
Published: April 2022

Zusammenfassung. In den letzten Jahren ist mir immer deutlicher geworden, dass Entwicklungen in der Pflege ohne gemeinsames Engagement der Pflegenden selbst nicht geschehen kann. Politik ist ein Ausgleich organisierter Interessen, wer nicht organisiert ist, nimmt nicht teil. Manchmal gibt es kleine „Brosamen“, Applaus, Prämien, Reförmchen. Die unendliche Leidensfähigkeit und Selbstlosigkeit machen den Beruf kaputt. Im Grunde arbeitet die Pflege seit vielen Jahren mit einer Notbesetzung, Pflegearbeit ist überall reduziert auf das Mindeste. Insbesondere Caring, Kümmern, Gespräche unterbleiben – obwohl die Erkenntnisse zunehmen, dass alles mit allem zusammenhängt. Im Hogrefe-Verlag haben wir immer wieder entsprechende Bücher auf den Weg gebracht. Ich möchte hier die Gelegenheit nutzen, drei Bücher nochmal vorzustellen. Ich würde sie als „Power Pack“ zur Politisierung von Pflege bezeichnen.
A Step Toward Making GPS More Resilient to Space Weather
Authors: Stanley Sarah
Published: April 2022

Researchers have developed a new mathematical model to more accurately capture how irregularities in Earth’s atmosphere interrupt signals from Global Navigation Satellite Systems.
Mantle Wedge Seismic Anisotropy and Shear Wave Splitting: Effects of Oblique Subduction
Authors: Kenyon Lindsey M. , Wada Ikuko
Published: April 2022

We investigate the evolution of olivine crystal preferred orientation (CPO) and its effect on local shear wave splitting (SWS) in the mantle wedge of oblique subduction zones. Based on model‐predicted 3‐D mantle wedge flow fields, we compute the A‐type and E‐type olivine CPO distribution for a range of subduction obliquity. The results show that the seismically fast axis does not necessarily align with the flow direction. To model the local SWS parameter distribution for oblique subduction zones, we apply a full range of initial polarization to multilayer models that approximate the model‐predicted CPO distributions. These models result in a bimodal SWS parameter distribution, which relaxes as subduction obliquity increases. Unlike non‐oblique subduction models, these models indicate considerable variations in the SWS parameters with subduction obliquity and initial polarization and also among the forearc, arc, and backarc regions. Because of this variability, a single SWS measurement cannot constrain the CPO distribution, and shear waves with a range of initial polarization are required to interpret the SWS parameters in oblique subduction zones. Our results indicate that 3‐D mantle wedge flow due to oblique subduction cannot explain commonly observed margin‐parallel fast direction in the forearc region but can explain margin‐normal fast directions that are observed in the arc and backarc regions of oblique subduction zones.
Estimating the Total Economic Costs of Nutrient Emission Reduction Policies to Halt Eutrophication in the Great Lakes
Authors: Garcia‐Hernandez Jorge A. , Brouwer Roy , Pinto Rute
Published: April 2022

The Great Lakes (GL) in North America are among the largest freshwater resources on the planet facing serious eutrophication problems as a result of excessive nutrient loadings due to population and economic growth. More than a third of Canada's GDP is generated in and around the GL. Hence, the economic interests affected by pollution and pollution control are high. New policies to reduce pollution are often insufficiently informed due to the lack of integrated models and methods that provide decision‐makers insight into the direct and indirect economic impacts of their policies. This study fills this knowledge gap and estimates the impacts of different total phosphorus (TP) restriction policy scenarios across the GL. A first of its kind multi‐regional hydro‐economic model is built for the Canadian GL, extended to include TP emissions from point and non‐point sources. This optimization model is furthermore extended with a pollution abatement cost function that allows sectors to also take technical measures to meet the imposed pollution reduction targets. The latter is a promising new avenue for extending existing hydro‐economic input‐output modeling frameworks. The results show decision‐makers the least cost‐way to achieve different TP emission reduction targets. The estimated cost to reduce TP emissions by 40% in all GL amounts to a total annual cost of 3 billion Canadian dollars or 0.15% of Canada's GDP. The cost structure changes substantially as policy targets become more stringent, increasing the share of indirect costs and affecting not only the economic activities around the GL, but the economy of Canada as a whole due to the tightly interwoven economic structure.
Africa’s Earth, Wind, and Fire Keep the Amazon Green
Authors: Besl J.
Published: March 2022

Jet streams sprinkle North African dust over the Amazon, providing the rain forest with much needed nutrients. Changing wind patterns and increasing smoke may shift the system.
Nuclear Aurora kinase A switches m6A reader YTHDC1 to enhance an oncogenic RNA splicing of tumor suppressor RBM4
Authors: Li SiSi , Qi YangFan , Yu JiaChuan , Hao YuChao , He Bin , Zhang MengJuan , Dai ZhenWei , Jiang TongHui , Li SuYi , Huang Fang , Chen Ning , Wang Jing , Yang MengYing , Liang DaPeng , An Fan , Zhao JinYao , Fan WenJun , Pan YuJia , Deng ZiQian , Luo YuanYuan , Guo Tao , Peng Fei , Hou ZhiJie , Wang ChunLi , Zheng FeiMeng , Xu LingZhi , Xu Jie , Wen QingPing , Jin BiLian , Wang Yang , Liu Quentin
Published: April 2022

Aberrant RNA splicing produces alternative isoforms of genes to facilitate tumor progression, yet how this process is regulated by oncogenic signal remains largely unknown. Here, we unveil that non-canonical activation of nuclear AURKA promotes an oncogenic RNA splicing of tumor suppressor RBM4 directed by m6A reader YTHDC1 in lung cancer. Nuclear translocation of AURKA is a prerequisite for RNA aberrant splicing, specifically triggering RBM4 splicing from the full isoform (RBM4-FL) to the short isoform (RBM4-S) in a kinase-independent manner. RBM4-S functions as a tumor promoter by abolishing RBM4-FL-mediated inhibition of the activity of the SRSF1-mTORC1 signaling pathway. Mechanistically, AURKA disrupts the binding of SRSF3 to YTHDC1, resulting in the inhibition of RBM4-FL production induced by the m6A-YTHDC1-SRSF3 complex. In turn, AURKA recruits hnRNP K to YTHDC1, leading to an m6A-YTHDC1-hnRNP K-dependent exon skipping to produce RBM4-S. Importantly, the small molecules that block AURKA nuclear translocation, reverse the oncogenic splicing of RBM4 and significantly suppress lung tumor progression. Together, our study unveils a previously unappreciated role of nuclear AURKA in m6A reader YTHDC1-dependent oncogenic RNA splicing switch, providing a novel therapeutic route to target nuclear oncogenic events.
High-temperature phonon-mediated superconductivity in monolayer Mg2B4C2
Authors: Singh Sobhit , Romero Aldo H. , Mella José D. , Eremeev Vitalie , Muñoz Enrique , Alexandrova Anastassia N. , Rabe Karin M. , Vanderbilt David , Muñoz Francisco
Published: April 2022

A two-dimensional material – Mg2B4C2, belonging to the family of the conventional superconductor MgB2, is theoretically predicted to exhibit superconductivity with critical temperature Tc estimated in the 47–48 K range (predicted using the McMillian-Allen-Dynes formula) without any tuning of external parameters such as doping, strain, or substrate-induced effects. The origin of such a high intrinsic Tc is ascribed to the presence of strong electron-phonon coupling and large density of states at the Fermi level. This system is obtained after replacing the chemically active boron-boron surface layers in a MgB2 slab by chemically inactive boron-carbon layers. Hence, the surfaces of this material are inert. Our calculations confirm the stability of 2D Mg2B4C2. We also find that the key features of this material remain essentially unchanged when its thickness is increased by modestly increasing the number of inner MgB2 layers.
Identification of gut microbial species linked with disease variability in a widely used mouse model of colitis
Authors: Forster Samuel C. , Clare Simon , Beresford-Jones Benjamin S. , Harcourt Katherine , Notley George , Stares Mark D. , Kumar Nitin , Soderholm Amelia T. , Adoum Anne , Wong Hannah , Morón Bélen , Brandt Cordelia , Dougan Gordon , Adams David J. , Maloy Kevin J. , Pedicord Virginia A. , Lawley Trevor D.
Published: April 2022

Experimental mouse models are central to basic biomedical research; however, variability exists across genetically identical mice and mouse facilities making comparisons difficult. Whether specific indigenous gut bacteria drive immunophenotypic variability in mouse models of human disease remains poorly understood. We performed a large-scale experiment using 579 genetically identical laboratory mice from a single animal facility, designed to identify the causes of disease variability in the widely used dextran sulphate sodium mouse model of inflammatory bowel disease. Commonly used treatment endpoint measures—weight loss and intestinal pathology—showed limited correlation and varied across mouse lineages. Analysis of the gut microbiome, coupled with machine learning and targeted anaerobic culturing, identified and isolated two previously undescribed species, Duncaniella muricolitica and Alistipes okayasuensis, and demonstrated that they exert dominant effects in the dextran sulphate sodium model leading to variable treatment endpoint measures. We show that the identified gut microbial species are common, but not ubiquitous, in mouse facilities around the world, and suggest that researchers monitor for these species to provide experimental design opportunities for improved mouse models of human intestinal diseases.
MeadoWatch: a long-term community-science database of wildflower phenology in Mount Rainier National Park
Authors: Manzanedo Rubén D. , John Aji , Sethi Meera L. , Theobald Elli J. , Brosi Berry , Jenkins Joshua , Kloss-Schmidt Ava , Lia Emilia , Schiffer Annie , Sevigny Jordana , Wilson Anna , Yogev Yonit , Hille Ris Lambers Janneke
Published: April 2022

We present a long-term and high-resolution phenological dataset from 17 wildflower species collected in Mt. Rainier National Park, as part of the MeadoWatch (MW) community science project. Since 2013, 457 unique volunteers and scientists have gathered data on the timing of four key reproductive phenophases (budding, flowering, fruiting, and seeding) in 28 plots over two elevational gradients alongside popular park trails. Trained volunteers (87.2%) and University of  Washington scientists (12.8%) collected data 3–9 times/week during the growing season, using a standardized method. Taxonomic assessments were highly consistent between scientists and volunteers, with high accuracy and specificity across phenophases and species. Sensitivity, on the other hand, was lower than accuracy and specificity, suggesting that a few species might be challenging to reliably identify in community-science projects. Up to date, the MW database includes 42,000+ individual phenological observations from 17 species, between 2013 and 2019. However, MW is a living dataset that will be updated through continued contributions by volunteers, and made available for its use by the wider ecological community.
Association between glucokinase regulator gene polymorphisms and serum uric acid levels in Taiwanese adolescents
Authors: Ho Li-Ju , Lu Chieh-Hua , Su Ruei-Yu , Lin Fu-Huang , Su Sheng-Chiang , Kuo Feng-Chih , Chu Nain-Feng , Hung Yi-Jen , Liu Jhih-Syuan , Hsieh Chang-Hsun
Published: April 2022

The glucokinase regulator gene (GCKR) is located on chromosome 2p23. It plays a crucial role in maintaining plasma glucose homeostasis and metabolic traits. Recently, genome-wide association studies have revealed a positive association between hyperuricemia and GCKR variants in adults. This study investigated this genetic association in Taiwanese adolescents. Data were collected from our previous cross-sectional study (Taipei Children Heart Study). The frequencies of various genotypes (CC, CT, and TT) or alleles (C and T) of the GCKR intronic single-nucleotide polymorphism (SNP) rs780094 and the coding SNP rs1260326 (Pro446Leu, a common 1403C-T transition) were compared between a total of 968 Taiwanese adolescents (473 boys, 495 girls) with hyperuricemia or normal uric acid levels on the basis of gender differences. Logistic and linear regression analyses explored the role of GCKR in abnormal uric acid (UA) levels. Boys had higher UA levels than girls (6.68 ± 1.29 and 5.23 ± 0.95 mg/dl, respectively, p < 0.001). The analysis of both SNPs in girls revealed that the T allele was more likely to appear in patients with hyperuricemia than the C allele. After adjusting for confounders, the odds ratio (OR) for hyperuricemia incidence in the TT genotype was 1.75 (95% confidence interval [CI] 1.02–3.00), which was higher than that in the C allele carriers in rs1260326 in the girl population. Similarly, the TT genotypes had a higher risk of hyperuricemia, with an OR of 2.29 (95% CI 1.11–4.73) for rs1260326 and 2.28 (95% CI 1.09–4.75) for rs780094, than the CC genotype in girl adolescents. The T (Leu446) allele of GCKR rs1260326 polymorphism is associated with higher UA levels in Taiwanese adolescent girls.
Classification of pleural effusions using deep learning visual models: contrastive-loss
Authors: Lee Jang Ho , Choi Chang-Min , Park Namu , Park Hyung Jun
Published: April 2022

Blood and fluid analysis is extensively used for classifying the etiology of pleural effusion. However, most studies focused on determining the presence of a disease. This study classified pleural effusion etiology employing deep learning models by applying contrastive-loss. Patients with pleural effusion who underwent thoracentesis between 2009 and 2019 at the Asan Medical Center were analyzed. Five different models for categorizing the etiology of pleural effusion were compared. The performance metrics were top-1 accuracy, top-2 accuracy, and micro-and weighted-AUROC. UMAP and t-SNE were used to visualize the contrastive-loss model’s embedding space. Although the 5 models displayed similar performance in the validation set, the contrastive-loss model showed the highest accuracy in the extra-validation set. Additionally, the accuracy and micro-AUROC of the contrastive-loss model were 81.7% and 0.942 in the validation set, and 66.2% and 0.867 in the extra-validation set. Furthermore, the embedding space visualization in the contrastive-loss model exhibited typical and atypical effusion results by comparing the true and false positives of the rule-based criteria. Therefore, classifying the etiology of pleural effusion was achievable using the contrastive-loss model. Conclusively, visualization of the contrastive-loss model will provide clinicians with valuable insights for etiology diagnosis by differentiating between typical and atypical disease types.
TOX4 facilitates promoter-proximal pausing and C-terminal domain dephosphorylation of RNA polymerase II in human cells
Authors: Liu Ziling , Wu Aiwei , Wu Zhen , Wang Talang , Pan Yixuan , Li Bing , Zhang Xumin , Yu Ming
Published: April 2022

TOX4 is one of the regulatory factors of PP1 phosphatases with poorly understood functions. Here we show that chromatin occupancy pattern of TOX4 resembles that of RNA polymerase II (Pol II), and its loss increases cellular level of C-terminal domain (CTD) phosphorylated Pol II but mainly decreases Pol II occupancy on promoters. In addition, elongation rate analyses by 4sUDRB-seq suggest that TOX4 restricts pause release and early elongation but promotes late elongation. Moreover, TT-seq analyses indicate that TOX4 loss mainly decreases transcriptional output. Mechanistically, TOX4 may restrict pause release through facilitating CTD serine 2 and DSIF dephosphorylation, and promote Pol II recycling and reinitiation through facilitating CTD serines 2 and 5 dephosphorylation. Furthermore, among the PP1 phosphatases, TOX4 preferentially binds PP1α and is capable of facilitating Pol II CTD dephosphorylation in vitro. These results lay the foundation for a better understanding of the role of TOX4 in transcriptional regulation.
A benzodiazepine activator locks Kv7.1 channels open by electro-mechanical uncoupling
Authors: Schreiber Julian A. , Möller Melina , Zaydman Mark , Zhao Lu , Beller Zachary , Becker Sebastian , Ritter Nadine , Hou Panpan , Shi Jingyi , Silva Jon , Wrobel Eva , Strutz-Seebohm Nathalie , Decher Niels , Schmitt Nicole , Meuth Sven G. , Düfer Martina , Wünsch Bernhard , Cui Jianmin , Seebohm Guiscard
Published: April 2022

Loss-of-function mutations in Kv7.1 often lead to long QT syndrome (LQTS), a cardiac repolarization disorder associated with arrhythmia and subsequent sudden cardiac death. The discovery of agonisticIKsmodulators may offer a new potential strategy in pharmacological treatment of this disorder. The benzodiazepine derivative (R)-L3 potently activates Kv7.1 channels and shortens action potential duration, thus may represent a starting point for drug development. However, the molecular mechanisms underlying modulation by (R)-L3 are still unknown. By combining alanine scanning mutagenesis, non-canonical amino acid incorporation, voltage-clamp electrophysiology and fluorometry, andin silicoprotein modelling, we show that (R)-L3 not only stimulates currents by allosteric modulation of the pore domain but also alters the kinetics independently from the pore domain effects. We identify novel (R)-L3-interacting key residues in the lower S4-segment of Kv7.1 and observed an uncoupling of the outer S4 segment with the inner S5, S6 and selectivity filter segments.
Efficient valley polarization of charged excitons and resident carriers in Molybdenum disulfide monolayers by optical pumping
Authors: Park Sangjun , Arscott Steve , Taniguchi Takashi , Watanabe Kenji , Sirotti Fausto , Cadiz Fabian
Published: April 2022

The roadmap of future innovative device developments foresees the reduction of material dimensions down to nanometer scale and the incorporation of novel degrees of freedom. For instance, electrons and holes in 2D semiconductors like MoS2 monolayers exhibit a unique coupling between the spin and the crystal momentum, also referred to as the valley. A crucial requirement for future applications is therefore the possibility to initialise the spin/valley degree of freedom in these materials. Here we investigate the optical initialisation of the valley degree of freedom in charge-tunable MoS2 monolayers encapsulated with hexagonal boron nitride at cryogenic temperatures. We report in photoluminescence a large steady state valley polarization of the different excitonic complexes following circularly-polarized laser excitation. We reveal efficient valley initialisation of positively-charged excitons, which have so far proved to be elusive in non-encapsulated monolayers due to defect and laser-induced large electron doping. We find that negatively-charged excitons present a polarization of 70% which is unusually large for non-resonant excitation. We attribute this large valley polarization to the particular band structure of MoS2. In addition, we demonstrate that circular excitation induces a dynamical polarization of resident electrons and holes––as recently shown in tungsten-based monolayers.
Black carbon emissions from traffic contribute substantially to air pollution in Nairobi, Kenya
Authors: Kirago Leonard , Gatari Michael J. , Gustafsson Örjan , Andersson August
Published: April 2022

Rapid urbanization and population growth drives increased air pollution across Sub-Saharan Africa with serious implications for human health, yet pollutant sources are poorly constrained. Here, we analyse fine particulate aerosol concentrations and radiocarbon composition of black carbon over a full annual cycle in Nairobi, Kenya. We find that particle concentrations exceed the World Health Organisation’s recommended safe limit throughout the year, with little seasonal variability in particle concentration or composition. Organics (49 ± 7%) and water-soluble inorganic ions, dominated by sulfates (13 ± 5%), constitute the largest contributors to the particle loadings. Unlike large cities on other continents, the fraction of black carbon in particles is high (15 ± 4%) suggesting black carbon is a prominent air pollutant in Nairobi. Radiocarbon-based source quantification indicates that fossil fuel combustion emissions are a dominant source of black carbon throughout the year (85 ± 3%). Taken together, this indicates that black carbon emissions from traffic are a key stressor for air quality in Nairobi.
Patterns and frequency of projected future tropical cyclone genesis are governed by dynamic effects
Authors: Murakami Hiroyuki , Wang Bin
Published: April 2022

Potential future changes in the genesis frequency and distribution of tropical cyclones are important for society, yet uncertain. Confidence in the model projections largely relies on whether we can physically explain why the models projected such changes. Here we analyze multi-model climate simulations, and find that future changes in the patterns and frequency of tropical cyclone genesis are largely governed by dynamic effects—that is, by human-induced changes in the atmospheric circulation. These large-scale circulation changes include decreases in the mid-level upward motion and lower-to-mid level cyclonic vorticity, and increases in vertical wind shear. Conversely, the thermodynamic effect—a result of increased maximum potential intensity in a warmer climate—would yield tropical cyclone genesis patterns that are opposite to the model projections. We conclude that dynamic changes in response to anthropogenic greenhouse gas emissions are an important factor in determining the response of tropical cyclones to global warming.
Exploiting heat transfer to achieve efficient photoelectrochemical CO2 reduction under light concentration
Authors: Kistler Tobias A. , Um Min Young , Cooper Jason K. , Sharp Ian D. , Agbo Peter
Published: April 2022

Photoelectrochemical carbon dioxide reduction to carbon monoxide at 16% solar-to-fuel conversion efficiency is achieved via electrolyte cooling.
Escherichia coli response to subinhibitory concentrations of colistin: insights from a study of membrane dynamics and morphology
Authors: Ilangumaran Ponmalar Ilanila , Swain Jitendriya , Basu Jaydeep K.
Published: April 2022

Sublethal doses of colistin alters the membrane dynamics through surface interactions.
Single source precursor route for the first graphene oxide–Pd6P nanocomposite: application in electrochemical hydrogen evolution reaction
Authors: Oswal Preeti , Sood Kritika , Singh Siddhant , Arora Aayushi , Bahuguna Anurag , Purohit Suraj , Kumar Arun
Published: April 2022

The first report of Pd6P nanospheres synthesized via a single-source precursor route, further immobilized over graphene oxide sheets and explored for applications in electrochemical hydrogen evolution reaction.
Precipitation of aqueous transition metals in particulate matter during the dithiothreitol (DTT) oxidative potential assay
Authors: Yalamanchili Jayashree , Hennigan Christopher J. , Reed Brian E.
Published: April 2022

Many aqueous transition metals in PM precipitate in the DTT assay.
Hierarchical Co@C-N synthesized by the confined pyrolysis of ionic liquid@metal–organic frameworks for the aerobic oxidation of alcohols
Authors: Ma Xiaomin , Chen Fengfeng , Zhang Xin , Wang Tingting , Yuan Shengrong , Wang Xusheng , Li Tianjin , Gao Junkuo
Published: April 2022

Co@C-N with hierarchical pores and highly active sites is synthesized by the pyrolysis of an ionic liquid@metal–organic framework.
Preparation, antibacterial activity, and electrocatalytic detection of hydrazine based on biogenic CuFeO2/PANI nanocomposites synthesized using Aloe barbadensis miller
Authors: Singh Pooja , Singh Kshitij RB , Verma Rahul , Prasad Priyanka , Verma Ranjana , Das Subha Narayan , Singh Jay , Singh Ravindra Pratap
Published: April 2022

This study reports the synthesis of B-CuFeO2 nanocomposites (NCs) and B-CuFeO2/PANI NCs from Aloe vera gel extract and their utility for label-free detection of hydrazine and their antibacterial efficiency.
Recent synthetic methodologies for imidazo[1,5-a]pyridines and related heterocycles
Authors: Ramana Reddy Mittapalli , Darapaneni Chandra Mohan , Patil Rajendra D. , Kumari Harshita
Published: April 2022

This review summarizes the recent developments in the construction of imidazo[1,5-a]pyridines using cyclocondensation, cycloaddition, oxidative cyclization, and transannulation reactions.
Asymmetric synthesis of δ-substituted-β-keto esters and β-substituted ketones via carboxyl-assisted site- and enantio-selective addition reactions
Authors: Zhu Huiling , Liu Peng , Liu Hongxin , Ahmed Ebrahim-Alkhalil M. A. , Hu Xingen , Li Juan , Xiao Hong-Ping , Li Xinhua , Jiang Jun
Published: April 2022

Highly site- and enantio-selective additions of polyfunctional nucleophiles to imines or carbonyls were achieved via a carboxyl-assisted strategy, affording δ-substituted-β-keto esters and β-substituted ketones with good yield and enantioselectivity.
Electroless deposition of RuPd nanoparticles on porous carbon for hydrogen evolution in acid and alkaline media
Authors: Wang Jiawei , Huang Yan , Zhang Xianren , Cao Dapeng , Wang Shitao
Published: April 2022

Porous carbon catalysts with bimetal Ru and Pd nanoparticles prepared by electroless deposition were used to catalyze hydrogen evolution in acidic and alkaline media efficiently.
Widespread subsonic turbulence in Ophiuchus North 1
Authors: Gong Yan , Liu Shu , Wang Junzhi , Zhu Weishan , Li Guang-Xing , Yang Wenjin , Sun Jixian
Published: April 2022

Context. Supersonic motions are common in molecular clouds. (Sub)sonic turbulence is usually detected toward dense cores and filaments. However, it remains unknown whether (sub)sonic motions at larger scales (≳1 pc) may be present in various environments.

Aims. Located at a distance of about 110 pc, Ophiuchus North 1 (Oph N1) is one of the nearest molecular clouds that would allow for an in-depth investigation of its turbulence properties via large-scale mapping observations of single-dish telescopes.

Methods. We carried out the 12CO (J = 1−0) and C18O (J = 1−0) imaging observations toward Oph N1 with the Purple Mountain Observatory 13.7 m telescope. The observations have an angular resolution of ~55″ (i.e., 0.03 pc).

Results. Most of the whole C18O emitting regions have Mach numbers of ≲1, demonstrating the large-scale (sub)sonic turbulence across Oph N1. Based on the polarization measurements, we estimate the magnetic field strength of the plane-of-sky component to be ≳9 µG. We infer that Oph N1 is globally sub-Alfvénic, and is supported against gravity mainly by the magnetic field. The steep velocity structure function can be caused by the expansion of the Sh 2–27 HII region or the dissipative range of incompressible turbulence.

Conclusions. Our observations reveal a surprising case of clouds that are characterized by widespread subsonic turbulence and a steep relation between the size and the linewidth. This cloud is magnetized where ion-neutral friction is assumed to play an important role.
Outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity. A systematic review
Authors: Elbardesy Hany , McLeod André , Ghaith Hazem S. , Hakeem Samir , Housden Philip
Published: April 2022

Background: When correcting severe genu varus deformity, knee surgeons must choose between performing a single or double-level osteotomy. This systematic review aims to provide this equipoise with some clarity. Patients and methods: We conducted this study following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement (PRISMA) and the Cochrane Handbook for systematic reviews and meta-analysis. Studies evaluating the effect of the double level osteotomy (DLO) or those comparing it to high tibial osteotomy (HTO) from all regions and written in any language were included. Results: Six studies were included in this systematic review. They were prepared and analysed using Review Manager V5.0 [Computer Program] (RevMan5). Performing DLO resulted in restoring patellar height, joint-line convergence angle (JLCA), and mMPTA to normal values. DLO was also more successful at avoiding joint line obliquity (JLO) in severe varus deformity when compared to HTO (P < 0.001). No significant difference was reported between the two cohorts regarding the mLPTA. DLO resulted in satisfactory short term KOOS and IKDC scores. The complication rate after DLO was 2.28%. Conclusions: DLO showed a low complication rate and satisfactory short term KOOS and IKDAC scores. Randomised control trials with long term follow-up comparing the DLO and HTO are recommended.
Theoretical investigations on photodissociation dynamics of deuterated alkyl halides CD3CH2F
Authors: Gu Shuangfei , Chin Chih-Hao , Zhu Tong , Zhang John Zeng Hui
Published: April 2022

The product branching ratio between different products in multichannel reactions is as important as the over-all rate of reaction, both in terms of practical applications (e.g. models of combustion or atmosphere chemistry) in understanding the fundamental mechanisms of such chemical reactions. A global ground state potential energy surface for the dissociation reaction of deuterated alkyl halide CD3CH2F was computed at the CCSD(T)/CBS//B3LYP/aug-cc-pVDZ level of theory for all species. The decomposition of CD3CH2F is controversial concerning C−F bond dissociation reaction and molecular (HF, DF, H2, D2, HD) elimination reaction. Rice-Ramsperger-Kassel-Marcus (RRKM) calculations were applied to compute the rate constants for individual reaction steps and the relative product branching ratios for the dissociation products were calculated using the steady-state approach. At the different energies studied, the RRKM method predicts that the main channel for DF or HF elimination from 1,2-elimination of CD3CH2F is through a four-center transition state, whereas D2 or H2 elimination from 1,1-elimination of CD3CH2F occurs through a direct three-center elimination. At 266, 248, and 193 nm photodissociation, the main product CD2CH2+DF branching ratios are computed to be 96.57%, 91.47%, and 48.52%, respectively; however, at 157 nm photodissociation, the product branching ratio is computed to be 16.11%. Based on these transition state structures and energies, the following photodissociation mechanisms are suggested: at 266, 248, 193 nm, CD3CH2F→absorption of a photon→TS5→the formation of the major product CD2CH2+DF; at 157 nm, CD3CH2F→absorption of a photon→D/F interchange of TS1→CDH2CDF→H/F interchange of TS2→CHD2CHDF→the formation of the major product CHD2+CHDF.
Enhanced crystal quality of perovskite via protonated graphitic carbon nitride added in carbon-based perovskite solar cells
Authors: Guo Mingxing , Liu Wenchao , Huang Junyan , Liu Jiaqi , Yin Shuhui , Leng Jing
Published: April 2022

The quality of perovskite layers has a great impact on the performance of perovskite solar cells (PSCs). However, defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films. It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization. Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride (p-g-C3N4) was successfully synthesized and doped into perovskite layer of carbon-based PSCs. The addition of p-g-C3N4 into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide (MAPbI3) crystal for obtaining flat perovskite surface with larger grain size, but also reduces intrinsic defects of perovskite layer. It is found that the p-g-C3N4 locates at the perovskite core, and the active groups -NH2/NH3 and NH have a hydrogen bond strengthening, which effectively passivates electron traps and enhances the crystal quality of perovskite. As a result, a higher power conversion efficiency of 6.61% is achieved, compared with that doped with g-C3N4 (5.93%) and undoped one (4.48%). This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.
Low-lying isomers of (TiO2)n (n=2−8) clusters
Authors: Wang Binli , Abdullahi Abubakar Sadiq , Wang Yahui , Fan Hong-Jun
Published: April 2022

Although there are diverse bond features of Ti and O atoms, so far only several isomers have been reported for each (TiO2)n cluster. Instead of the widely used global optimization, in this work, we search for the low-lying isomers of (TiO2)n (n=2−8) clusters with up to 10000 random sampling initial structures. These structures were optimized by the PM6 method, followed by density functional theory calculations. With this strategy, we have located many more low-lying isomers than those reported previously. The number of isomers increases dramatically with the size of the cluster, and about 50 isomers were found for (TiO2)7 and (TiO2)8 with the energy within 30 kcal/mol. Furthermore, new lowest isomers have been located for (TiO2)5 and (TiO2)8, and isomers with three terminal oxygen atoms, five coordinated oxygen atoms as well as six coordinated titanium atoms have been located. Our work highlights the diverse structural features and a large number of isomers of small TiO2 clusters.
Ultrafast decay dynamics of 2-hydroxypyridine excited to S1 electronic state
Authors: Min Yan-jun , Yuan Wen-peng , Yang Dong-yuan , Dai Dong-xu , Yu Sheng-rui , Wu Guo-rong , Yang Xue-ming
Published: April 2022

The S1 state decay dynamics of 2-hydroxypyridine following UV excitation at a wavelength range of 276.9−250.0 nm is investigated using femtosecond time-resolved photoelectron imaging technique. Based on pump wavelength dependence of the decay dynamics, a refined decay picture is proposed. At pump wavelength of 276.9 nm, the S1 state is depopulated through intersystem crossing to lower triplet state(s). At 264.0 nm, both intersystem crossing to lower triplet state(s) and internal conversion to the ground state are in operation. At 250.0 nm, internal conversion to the ground state becomes dominated.
Effects of vibrational and rotational excitations on dissociative chemisorption dynamics of N2 on Fe(111)
Authors: Shi Huixia , Liu Tianhui , Fu Yanlin , Wu Hao , Fu Bina , Zhang Dong H.
Published: April 2022

The dissociative chemisorption of N2 is the rate-limiting step for ammonia synthesis in industry. Here, we investigated the role of initially vibrational excitation and rotational excitation of N2 for its reactivity on the Fe(111) surface, based on a recently developed six-dimensional potential energy surface. Six-dimensional quantum dynamics study was carried out to investigate the effect of vibrational excitation for incidence energy below 1.6 eV, due to significant quantum effects for this reaction. The effects of vibrational and rotational excitations at high incidence energies were revealed by quasiclassical trajectory calculations. We found that raising the translational energy can enhance the dissociation probability to some extent, however, the vibrational excitation or rotational excitation can promote dissociation more efficiently than the same amount of translational energy. This study provides valuable insight into the mode-specific dynamics of this heavy diatom-surface reaction.
Overcoming misconceptions and enhancing student's physical understanding of civil and environmental engineering fluid mechanics
Authors: Kaye N. B. , Ogle J.
Published: April 2022

Undergraduate students of fluid mechanics bring a range of preconceptions to the classroom. The sometimes counterintuitive nature of fluid mechanics means that many of these preconceptions are, in fact, misconceptions. Such misconceptions can be hard to address and can persist even among nominally high-performing students. A pedagogical approach (i.e., predict, test, and reflect) is presented. The approach provides an effective structure for addressing and correcting misconceptions through the use of low-cost hands-on activities that students can quickly and easily undertake during regular class time. The activities all have the same structure of describing the activity, having students make a prediction based on their intuition/prior experience, testing that prediction using simple, low-cost activities, reflecting on the success or failure of the prior prediction, and analysis of the activity to illustrate the correct conception of the flow. Course evaluations indicate that students have found this approach very helpful in improving their conceptual understanding in an introductory engineering fluid mechanics class.
Non-Markovian rate theory on a multidimensional reaction surface: Complex interplay between enhanced configuration space and memory
Authors: Acharya Subhajit , Bagchi Biman
Published: April 2022

A theory of barrier crossing rate on a multidimensional reaction energy surface is presented. The theory is a generalization of the earlier theoretical schemes to higher dimensions, with the inclusion of non-Markovian friction along both the reactive and the nonreactive coordinates. The theory additionally includes the bilinear coupling between the reactive and the nonreactive modes at the Hamiltonian level. Under suitable conditions, we recover the rate expressions of Langer and Hynes and establish a connection with the rate treatment of Pollak. Within the phenomenology of generalized Langevin equation description, our formulation provides an improvement over the existing ones because we explicitly include both the non-Markovian effects along the reaction coordinate and the bilinear coupling at the Hamiltonian level. At intermediate-to-large friction, an increase in dimensionality by itself tends to reduce the rate, while the inclusion of the memory effects increases the rate. The theory predicts an increase in rate when off-diagonal friction terms are included. We present a model calculation to study isomerization of a stilbene-like molecule using the prescription of Hochstrasser and co-workers on a two-dimensional reaction energy surface, employing Zwanzig–Bixon hydrodynamic theory of frequency-dependent friction. The calculated rate shows a departure from the predictions of Langer’s theory and also from the two-dimensional transition state theory.