bluuebunny/crossref_metadata_2025 huggingface dataset:
Instilling safety culture in the passenger rail transport industry within the South African context
Authors: Maluleke Khulumane
Published: July 2013

South Africa has two major rail operators that constitute the rail transport industry. These are Transnet Freight Rail (TFR), which operates freight and the Passenger Rail Agency of South Africa (PRASA). Although the Railway Safety Regulator (2011:29) reported the year on year declining trend of collisions, the main concern is that the costs incurred for each year’s incidents is escalating. This article is concerned with the declining safety standards of these operators as evidenced by 742 collisions recorded during the 2011/2012 financial year for both operators. The focus is mainly on collisions during the movement of rolling stock within the PRASA environment. The analysis of the occurrences is narrowed down, with the emphasis on the province of Gauteng. In the analysis of the causes of these collisions, the problems that led to the root causes of these collisions is reported. Of critical importance is that every transport operator is faced with the challenges of how to effectively respond to the basic transport needs and requirements of the travelling public. The transport users’ need is to travel between the two geographical points. During the journey between these geographical points, the operator has safety and security requirements and must provide a reliable, accessible and affordable transport system. As the travelling public becomes more affluent, the transport needs become open ended and require much more rational public choices. The rail transport system remains a vital or indispensable business sector of the economy. By investing in new technology, rolling stock and infrastructure, we woud see an increase in innovation, competitiveness, and an elevated standard of living.
Virgilia divaricata may facilitate forest expansion in the afrotemperate forests of the southern Cape, South Africa
Authors: Coetsee Corli , Wigley Benjamin J.
Published: July 2013

Virgilia divaricata is a fast-growing nitrogen-fixing tree species often found on the margins of forest in the southern Cape of South Africa and is particularly abundant after fire. However, V. divaricatamay invade fynbos even in the absence of fire and it has been described as a forest precursor. We investigated whether V. divaricata enriches soil fertility after its invasion into fynbos areas adjacent to forests. We measured soil organic carbon and soil nutrients at four sites. At each site, three vegetation types (forest, V. divaricata and fynbos) were examined on the same soil type and at the same elevation. Our results showed that, on average, soils taken from V. divaricata stands had higher nitrogen and phosphorus values than the adjacent fynbos soils, with either lower or similar values to the adjacent forest soils. Higher soil fertility under V. divaricata, together with their shading effect, may create conditions favourable for shade-loving forest species dependent on an efficient nutrient cycle in the topsoil layers, and less favourable for shade-hating fynbos species, which are generally adapted to low soil fertility. We suggest that the restoration of the nutrient cycle found in association with forest may be accelerated under V. divaricata compared with other forest precursor species, which has important consequences for the use of V. divaricata in ecosystem restoration.Conservation implications: Alien plantations in the Outeniqua Mountains are being phased out and the areas are being incorporated into the Garden Route National Park. Fynbos areas are increasingly being invaded by forest and thicket species owing to fire suppression in lower-lying areas. An improved understanding of the fynbos–forest boundary dynamics will aid in efficient management and restoration of these ecosystems.
Maïdo observatory: a new altitude station facility at Reunion Island (21° S, 55° E) for long-term atmospheric remote sensing and in-situ measurements
Authors: Baray J.-L. , Courcoux Y. , Keckhut P. , Portafaix T. , Tulet P. , Cammas J.-P. , Hauchecorne A. , Godin-Beekmann S. , De Mazière M. , Hermans C. , Desmet F. , Sellegri K. , Colomb A. , Ramonet M. , Sciare J. , Vuillemin C. , Hoareau C. , Dionisi D. , Duflot V. , Vérèmes H. , Porteneuve J. , Gabarrot F. , Gaudo T. , Metzger J.-M. , Payen G. , Leclair de Bellevue J. , Barthe C. , Posny F. , Ricaud P. , Abchiche A. , Delmas R.
Published: July 2013

Abstract. Since the nineties, atmospheric measurement systems have been deployed at Reunion Island, mainly for monitoring the atmospheric composition in the framework of NDSC/NDACC (Network for the Detection of Stratospheric Change/Network for the Detection of Atmospheric Composition Change). The location of Reunion Island presents a great interest because there are very few multi-instrumented stations in the tropics and particularly in the Southern Hemisphere. In 2012, a new observatory was commissioned in Maïdo at 2200 m a.s.l.: it hosts various instruments for atmospheric measurements, including LiDAR systems, spectro-radiometers and in situ gases and aerosols measurements. This new high-altitude Maïdo station allows: 1. To improve the performance of the optical instruments above the marine boundary layer, and to open new perspectives on upper troposphere and lower stratosphere studies. 2. To develop in-situ measurements of the atmospheric composition for climate change survey, in a reference site in the tropical/subtropical region of the Southern Hemisphere. 3. To offer trans-national access to host experiments or measurement campaigns for focused process studies.
Shifting environmental controls on CH4 fluxes in a sub-boreal peatland
Authors: Pypker T. G. , Moore P. A. , Waddington J. M. , Hribljan J. A. , Chimner R. C.
Published: July 2013

Abstract. We monitored CO2 and CH4 fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH4 from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH4 over the measurement period. Net daily CH4 fluxes increased from 70 mg m−2 d−1 to 220 mg m−2 d−1 from mid May to mid July. After July, CH4 losses steadily declined to approximately 50 mg m−2 d−1 in late September. During the study period, the peatland lost 17.4 g CH4 m−2. Both abiotic and biotic variables were correlated with changes in CH4 flux. When the different variables were analyzed together, the preferred model included mean daily soil temperature at 20 cm, daily net ecosystem exchange (NEE) and the interaction between mean daily soil temperature at 20 cm and NEE (R2 = 0.47, p value < 0.001). The interaction was important because the relationship between daily NEE and mean daily soil temperature with CH4 flux changed in conjunction with changes in daily NEE. On days when daily NEE was negative, 25% of the CH4 flux could be explained by changes in NEE, however on days when daily NEE was positive, there was no correlation between daily NEE and the CH4 flux. In contrast, daily mean soil temperature at 20 cm was poorly correlated to changes in CH4 when NEE was negative (17%), but the correlation increased to 34% when NEE was positive. The interaction between daily NEE and mean daily soil temperature at 20 cm indicates shifting environmental controls on the CH4 flux throughout the growing season.
Bayesian parameter estimation and interpretation for an intermediate model of tree-ring width
Authors: Tolwinski-Ward S. E. , Anchukaitis K. J. , Evans M. N.
Published: July 2013

Abstract. We present a Bayesian model for estimating the parameters of the VS-Lite forward model of tree-ring width for a particular chronology and its local climatology. The scheme also provides information about the uncertainty of the parameter estimates, as well as the model error in representing the observed proxy time series. By inferring VS-Lite's parameters independently for synthetically generated ring-width series at several hundred sites across the United States, we show that the algorithm is skillful. We also infer optimal parameter values for modeling observed ring-width data at the same network of sites. The estimated parameter values covary in physical space, and their locations in multidimensional parameter space provide insight into the dominant climatic controls on modeled tree-ring growth at each site as well as the stability of those controls. The estimation procedure is useful for forward and inverse modeling studies using VS-Lite to quantify the full range of model uncertainty stemming from its parameterization.
A fluid-mechanics based classification scheme for surface transient storage in riverine environments: quantitatively separating surface from hyporheic transient storage
Authors: Jackson T. R. , Haggerty R. , Apte S. V.
Published: July 2013

Abstract. Surface transient storage (STS) and hyporheic transient storage (HTS) have functional significance in stream ecology and hydrology. Currently, tracer techniques couple STS and HTS effects on stream nutrient cycling; however, STS resides in localized areas of the surface stream and HTS resides in the hyporheic zone. These contrasting environments result in different storage and exchange mechanisms with the surface stream, which can yield contrasting results when comparing transient storage effects among morphologically diverse streams. We propose a fluid mechanics approach to quantitatively separate STS from HTS that involves classifying and studying different types of STS. As a starting point, a classification scheme is needed. This paper introduces a classification scheme that categorizes different STS in riverine systems based on their flow structure. Eight STS types are identified and some are subcategorized based on characteristic mean flow structure: (1) lateral cavities (emergent and submerged); (2) protruding in-channel flow obstructions (backward- and forward-facing step); (3) isolated in-channel flow obstructions (emergent and submerged); (4) cascades and riffles; (5) aquatic vegetation (emergent and submerged); (6) pools (vertically submerged cavity, closed cavity, and recirculating reservoir); (7) meander bends; and (8) confluence of streams. The long-term goal is to use the classification scheme presented to develop predictive mean residence times for different STS using field-measurable hydromorphic parameters and obtain an effective STS mean residence time. The effective STS mean residence time can then be deconvolved from the transient storage residence time distribution (measured from a tracer test) to obtain an estimate of HTS mean residence time.
Le Fardeau de la légèreté : une étude de Kimchi d’Ook Chung
Authors: Yang Ziyan
Published: July 2013

Depuis la naissance de la littérature du Québec qui vise la construction de l’identité québécoise, le rapport entre la saisie du Soi et la perception de l’Autre constitue un noyau dur du discours littéraire. Aujourd’hui, avec l’émergence des écrivains migrants ou néo-québécois (différenciés des écrivains québécois « de souche »), le Soi et l’Autre se rapprochent à tel point que leurs frontières se dissolvent dans cette écriture dite « migrante ». Cet article s’intéresse à la représentation de l’identité dans le premier roman Kimchi par Ook Chung, un écrivain québécois d’origine asiatique. En nous appuyant sur les recherches de Charles Taylor et de Paul Ricoeur portant sur la notion de l’identité, nous réfléchissons d’abord sur la dialectique entre le Soi et l’Autre dans la quête identitaire du protagoniste. Ensuite, nous analysons le langage de Chung à la croisée des cultures selon le concept de l’« hybridité » proposé par Homi Bhabha. Finalement, nous portons notre attention au rôle de l’art et de l’écriture dans l’élaboration identitaire chez Chung.
Keep calm and reboot – how cells restart transcription after DNA damage and DNA repair
Authors: Donnio Lise‐Marie , Giglia‐Mari Giuseppina
Published: July 2024

The effects of genotoxic agents on DNA and the processes involved in their removal have been thoroughly studied; however, very little is known about the mechanisms governing the reinstatement of cellular activities after DNA repair, despite restoration of the damage‐induced block of transcription being essential for cell survival. In addition to impeding transcription, DNA lesions have the potential to disrupt the precise positioning of chromatin domains within the nucleus and alter the meticulously organized architecture of the nucleolus. Alongside the necessity of resuming transcription mediated by RNA polymerase 1 and 2 transcription, it is crucial to restore the structure of the nucleolus to facilitate optimal ribosome biogenesis and ensure efficient and error‐free translation. Here, we examine the current understanding of how transcriptional activity from RNA polymerase 2 is reinstated following DNA repair completion and explore the mechanisms involved in reassembling the nucleolus to safeguard the correct progression of cellular functions. Given the lack of information on this vital function, this Review seeks to inspire researchers to explore deeper into this specific subject and offers essential suggestions on how to investigate this complex and nearly unexplored process further.
SAMHSA requests public comment on ICCPUD alcohol intake and health study
Authors: Knopf Alison
Published: July 2024

Public comment on the proposed Alcohol Intake and Health (AIH) study methodology is due by Aug. 2, 2024. The federal Interagency Coordinating Committee on the Prevention of Underage Drinking (ICCPUD) announced its proposed methodology for the study, which includes literature reviews, interviews with experts and interviews with a population sample, in the Federal Register on June 28. ICCPUD and the Substance Abuse and Mental Health Services Administration (SAMHSA) jointly announced the methodology, which, despite ICCPUD's name, is not related to underage drinking only. Comments go to SAMHSA, which is particularly interested in the following.
NIAAA: Craving reduction and alcohol—a measure of recovery?
Authors: Knopf Alison
Published: July 2024

In the last issue, we wrote about research using craving reduction as a measure of recovery from drug addiction (see ADAW https://onlinelibrary.wiley.com/doi/10.1002/adaw.34167), based on coverage at the College on Problems of Drug Dependence (CPDD) from National Institute on Drug Abuse (NIDA) researchers. We wanted to find out whether craving reduction can also be used as a measure of recovery from alcohol use disorder (AUD). So we asked George F. Koob, Ph.D., director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), who, with Laura E. Kwako, Ph.D., chief of NIAAA's treatment, health services and recovery branch, responded to our questions.
An Advanced Anode Composed of Layered Single‐Crystal Metal–Organic Framework Material for Ultra‐Long Cycle‐Life Sodium‐Ion Batteries
Authors: Shuang Wei , Wang Ya , Wu Yujun , Ma Nana , Chen Fuyou , Wang Xin , Yan Wei , Bai Zhengyu , Yang Lin , Zhang Jiujun
Published: July 2024

Developing advanced anode materials for sodium‐ion batteries (SIBs) is a frontier and hotspot research for clean and sustainable electricity energy storage and conversion. However, it is still challenging to obtain anode materials with high stability, multiple active sites, and high conductivity. In this paper, an advanced metal–organic framework (MOF)‐based anode material (Co‐HITP), which integrates multiple advantages into one, is successfully synthesized through a sodiation‐stimulated in situ reconstruction. The Co‐HITP possesses a stable single‐crystal structure, expanded spacing layers, abundant sites, and good conductivity, and exhibits superior properties with ultra‐long cycling stability (ultralow decay rate ≈0.001% per cycle after 15 000 cycles at 8 A g−1), high reversible capacity (450.1 mA h g−1 at 0.2 A g−1), and excellent rate performance. Both experimental results and theoretical calculation reveal that the anode remains a stable structure after long cycling, attributed to the single‐crystal structure with d‐π hybridization and π–π interaction, and the minimum structural unit stores 6Na+ ions of C═N sites and 8Na+ ions of aromatic rings. This discovery is significant for developing advanced anode materials with integrated advantages for SIBs.
PbSe Quantum Dot Superlattice Thin Films for Thermoelectric Applications
Authors: Sousa Viviana , Goto Masahiro , Claro Marcel S. , Pyrlin Sergey , Marques Luis , Modin Evgeny B. , Lebedev Oleg I. , Alizadeh Siavash M. , Freitas Cátia , Vieira Eliana M. F. , Kovnir Kirill , Alpuim Pedro , Mori Takao , Kolen'ko Yury V.
Published: July 2024

An unusual self‐assembly pattern is observed for highly ordered 1500‐nm‐thick films of monodisperse 13‐nm‐sized colloidal PbSe quantum dots, originating from their faceted truncated cube‐like shape. Specifically, self‐assembled PbSe dots exhibited attachment to the substrate by <001> planes followed by an interconnection through the {001} facets in plan‐view and {110}/{111} facets in cross‐sectional‐view, thus forming a cubic superlattice. The thermoelectric properties of the PbSe superlattice thin films are investigated by means of frequency domain thermoreflectance, scanning thermal probe microscopy, and four‐probe measurements, and augmented by computational efforts. Thermal conductivity of the superlattice films is measured as low as 0.7 W m−1 K−1 at room temperature due to the developed nanostructure. The low values of electrical conductivity are attributed to the presence of insulating oleate capping ligands at the dots’ surface and the small contact area between the PbSe dots within the superlattice. Experimental efforts aiming at the removal of the oleate ligands are conducted by annealing or molten‐salt treatment, and in the latter case, yielded a promising improvement by two orders of magnitude in thermoelectric performance. The result indicates that the straightforward molten‐salt treatment is an interesting approach to derive thermoelectric dot superlattice thin films over a centimeter‐sized area.
Methods for Color Center Preserving Hydrogen‐Termination of Diamond
Authors: McCloskey Daniel J. , Roberts Daniel , Rodgers Lila V. H. , Barsukov Yuri , Kaganovich Igor D. , Simpson David A. , de Leon Nathalie P. , Stacey Alastair , Dontschuk Nikolai
Published: July 2024

Chemical functionalization of diamond surfaces by hydrogen is an important method for controlling the charge state of near‐surface fluorescent color centers, an essential process in fabricating devices such as diamond field‐effect transistors and chemical sensors, and a required first step for realizing families of more complex terminations through subsequent chemical processing. In all these cases, termination is typically achieved using hydrogen plasma sources that can etch or damage the diamond, as well as deposited materials or embedded color centers. This work explores alternative methods for lower‐damage hydrogenation of diamond surfaces, specifically the annealing of diamond samples in high‐purity, non‐explosive mixtures of nitrogen and hydrogen gas, and the exposure of samples to microwave hydrogen plasmas in the absence of intentional stage heating. The effectiveness of these methods are characterized by x‐ray photoelectron spectroscopy (XPS), and comparison of the results to density‐functional modelling of the surface hydrogenation energetics implicates surface oxygen ligands as the primary factor limiting the termination quality of annealed samples. Finally, photoluminescence (PL) spectroscopy is used to verify that both the annealing and reduced sample temperature plasma methods are non‐destructive to near‐surface ensembles of nitrogen‐vacancy (NV) centers, in stark contrast to plasma treatments that use heated sample stages.
Gradient‐Interpenetrating Polymer Networks in 3D Printed Lattices for Tunable and Enhanced Energy Absorption
Authors: Sampson Kathleen L. , Li Hao , Laqua Kurtis , Aranguren van Egmond Derek , Dickson Laura E. , Barroeta Robles Julieta , Lamouche Justin , Guthrie Aria , Ashrafi Behnam , Zou Shan , Chen Maohui , Bell Joshua , Paquet Chantal
Published: July 2024

3D printing provides the potential to enhance mechanical properties by fabricating complex structures with diverse materials; however, most high‐resolution 3D printing techniques require custom printers to incorporate multiple materials and/or result in poor material interfacial bonding. Here, energy absorption properties are enhanced with 3D lattice structures fabricated via vat photopolymerization comprising multiple materials forming a gradient‐interpenetrating polymer network (gradient‐IPN). The gradient‐IPN is incorporated by swelling the 3D printed elastomeric lattice in a photoresin that yields a stiff shell‐soft core structure. This straightforward post‐3D printing technique delivers an unprecedented degree of structural property customization through polymer gradients in lattice struts with shells of tunable stiffness and flexible elastomeric cores to achieve a broad continuum spectrum of mechanical properties within one simple system. The gradient aids in the distribution of stress and limits fracture between materials typically observed in multimaterial lattices. The gradient‐IPN lattices are fully recoverable and exhibit over 4 to 33 times higher toughness after compression, compared to copolymer (same composition as the gradient‐IPN) or purely elastomeric lattices, respectively. This highly versatile approach to modifying 3D printed lattices yields the unique combination of load bearing capabilities with viscoelasticity desirable for high performance materials in impact protection.
Wafer‐Scale Demonstration of Polycrystalline MoS2 Growth on 200 mm Glass and SiO2/Si Substrates by Plasma‐Enhanced Atomic Layer Deposition
Authors: Jagosz Julia , Willeke Leander , Gerke Nils , Becher Malte J. M. J. , Plate Paul , Kostka Aleksander , Rogalla Detlef , Ostendorf Andreas , Bock Claudia
Published: July 2024

2D materials like transition metal dichalcogenides (TMDCs) have been widely studied and are a gateway to modern technologies. While research today is mostly carried out on a laboratory scale, there is an intensive need for reliable processes on a wafer‐scale, starting with monolayer‐precise deposition of high‐quality films. In this work, a plasma‐enhanced atomic layer deposition (PEALD) process is developed on a 200 mm SiO2/Si substrate. The layers are investigated regarding crystallinity, composition, homogeneity, microstructure, topography, and electrical properties. The process is then applied on 200 mm alkali‐free glass wafers aiming toward flexible electronics and compatibility with Si processes. A complete coverage of the wafer with a satisfying uniformity is achieved on both substrates and direct polycrystalline growth of MoS2 films is verified on the entire wafer at a substrate temperature of T = 230 °C. On glass, the deposited MoS2 films exhibit a higher crystallinity and are more planar compared to the SiO2/Si substrate. Furthermore, application relevant few‐nanometer thick layers are investigated in detail. This low‐temperature process inspires optimism for future direct integration of 2D‐materials in an economical bottom‐up approach on a wide variety of substrates, thus paving the way for industrial mass production.
Highly Stable Red Emissive Organic Semiconductor Materials with Low Amplified Spontaneous Emission Thresholds
Authors: Rahane Vijay P. , Roseli Ras Baizureen , Ireland Alexander R. , Gale Innes , Shukla Atul , Moore Evan G. , Krenske Elizabeth H. , Namdas Ebinazar B. , Jain Nidhi , Lo Shih‐Chun
Published: July 2024

Excited‐state intramolecular proton transfer (ESIPT) chromophores have attracted considerable attention as promising gain media for organic lasers, particularly in amplified spontaneous emission (ASE) due to their advantageous characteristics. These include an intrinsic four‐level photocycle, significant separation between absorption and emission spectra, and enhanced emission efficiency facilitated by aggregate‐induced emission. This study investigates the amplification of π‐conjugation in hydroxyphenyl‐benzothiazole (HBT)‐based ESIPT materials via dimerization to intensify ESIPT processes, surge absorption cross‐section, enhance optical gain, and induce a redshift in emission spectra. Computational study shows that the ESIPT processes of the new dimers proceed through single proton transfer where the second proton transfer is not accessible. While the ESIPT photocycle does not extend to both HBT moieties of the dimers, the dimers foster more efficient ESIPT processes in both solution and solid states than their parent HBT, resulting in substantial Stokes shifts (>233 nm). Moreover, both dimers exhibit enhanced solid‐state photoluminescence quantum yields, reaching up to ≈55%, and low solid‐state ASE threshold values (≈6.8 µJ cm−2) in the red region. Remarkably, the new dimers demonstrate excellent thermal and photostability with notably reduced spectral overlap compared to their parent, highlighting the potential utility of the approaches to developing new organic solid‐state laser materials.
Sensors for Antibiotics Susceptibility Testing—Recent Advances
Authors: Riester Oliver , Laufer Stefan , Mertelsmann Roland , Deigner Hans‐Peter
Published: July 2024

The age of antibiotics, which began with the discovery of penicillin in 1929, marks an important period in medical history, as deadly bacterial infections seemed to be a thing of the past. However, the tide turned as more and more resistance to all existing antibiotics emerged, leading to the still ongoing era of antibiotic resistance. To counter this development and slow it down, it is important to administer the appropriate, effective antibiotics, which requires the clinical transition from empirical to targeted antibiotic therapy. Antimicrobial susceptibility testing (AST) is a key pillar in the implementation of targeted antibiotic therapy. This review provides an overview of the different phenotypic and genotypic AST methods with their advantages and disadvantages, focusing on the turnaround time from patient to result, including preculture. In addition, an outlook on their future potential is given, also considering the impact of artificial intelligence on this field.
Role of Al Vacancies in Thermodynamic Stability and Elastic Properties of AlB2${\rm AlB}_{2}$‐type (Ta,Al)B2${\rm B}_{2}$: A First‐Principles Study
Authors: Ektarawong Annop , Atthapak Chayanon , Alling Björn
Published: July 2024

‐type is one of the transition‐metal diborides, a class of refractory ceramics, that has increasingly received attention due particularly to their potential for hard‐coating applications. In this work, the first‐principles calculations are performed, in combination with the cluster‐expansion method, to investigate the effect of mixing with on the thermodynamic stability, structural parameters, electronic density of states, and mechanical behavior of the resulting (Ta,Al) solid solutions. It is found that the solid solutions display the chemical ordering of Ta and Al atoms both residing on the metal sublattice of the material, together with the preference for partial substitution of vacancies for Al atoms. This results in the formation of Al‐deficient (Ta,Al) with the chemical composition , predicted to be thermodynamically stable even at absolute zero in the ternary Ta−Al−B system. It is further found that such formation of Al vacancies in (Ta,Al) not only enhances the stability of the solutions but also improves their elastic properties and hardness, both of which could be attributed to the effect of electronic band filling. This investigation indeed sheds light on the interplay between the mixing of Ta and Al atoms and the presence of Al vacancies on the alloying and mechanical behaviors of (Ta,Al), and it thus offers valuable insights for further research and development of these ceramics.
High‐n Phase Suppression for Efficient and Stable Blue Perovskite Light‐Emitting Diodes
Authors: Shen Piaoyang , Ding Shuo , Tang Zhaobing , Qian Lei , Zhang Ting , Xiao Peng , Chen Tao , Chen Hao , Zhang Xinyu , Ren Yong , Zhao Dewei , Xiang Chaoyu
Published: July 2024

Quasi‐2D perovskites light‐emitting diodes (PeLEDs) have achieved significant progress due to their superior optical and electronic properties. However, the blue PeLEDs still exist inefficient energy transfer and electroluminescence performance caused by mixed multidimensional phase distribution. In this work, transition metal salt (zinc bromide, ZnBr2) is introduced to modulate phase distributions by suppressing the nucleation of high n phase perovskites, which effectively shortens the energy transfer path for blue emission. Moreover, ZnBr2 also facilitates energy level matching and reduces non‐radiative recombination, thus improving electroluminescence (EL) efficiency. Benefiting from these combined improvements, an efficient blue PeLEDs is obtained with a maximum external quantum efficiency (EQE) of 16.2% peaking located at 486 nm. This work provides a promising approach to tune phase distribution of quasi‐2D perovskites and achieving highly efficient blue PeLEDs.
Reprogramming of the Aurantinin Polyketide Assembly Line to Synthesize Auritriacids by Excising an Atypical Enoyl‐CoA Hydratase Domain
Authors: Wang Dacheng , Mao Huijin , Zhao Zelian , Liu Lilu , Chen Yihua , Li Pengwei
Published: July 2024

Modular polyketide synthases (PKSs) are capable of synthesizing diverse natural products with fascinating bioactivities. Canonical enoyl‐CoA hydratases (ECHs) are components of the β‐branching cassette that modifies the polyketide chain by adding a β‐methyl branch. Herein, it is demonstrated that the deletion of an atypical ECHQ domain (featuring a Q280 residue) of Art21, a didomain protein contains an ECHQ domain and a thioesterase (TE) domain, reprograms the polyketide assembly line from synthesizing tetracyclic aurantinins (ARTs) to bicyclic auritriacids (ATAs) with much lower antibacterial activities. Genes encoding the ECHQ‐TE didomain proteins distribute in many PKS gene clusters from different bacteria. Significantly, the ART PKS machinery can be directed to make ARTs, ATAs, or both of them by employing appropriate ECHQ‐TE proteins, implying a great potential for using this reprogramming strategy in polyketide structure diversification.
Linking Fast Sodium Conduction with Low‐Temperature Hydrogen Release in Sodium Borohydride
Authors: Salman Muhammad Saad , Srivastava Kshitij , Muñiz César Menéndez , Aguey‐Zinsou Kondo‐Francois
Published: July 2024

Complex hydrides, such as sodium borohydride (NaBH4), are attractive materials for hydrogen storage because of their high hydrogen capacity. However, practical application of these materials is limited because of their unfavorable hydrogen thermodynamics and poor kinetics. Herein, it is demonstrated that the inclusion of BF4− in NaBH4 results in remarkable Na+ conductivity of 1.5 × 10−3 S cm−1, which is 10 000 times higher compared to pure NaBH4 (7.0 × 10−8 S cm−1) at 115 °C. The ionic conductivity is also comparable to values reported for some of the best borohydride‐based conductors reported to date. More remarkably, this improvement of ionic conductivity is found to be correlated to lower hydrogen release temperatures for BF4−‐modified NaBH4 releasing hydrogen at a temperature of 200 °C instead of 510 °C in the case of pristine NaBH4. Nudged elastic band calculations based on density functional theory reveal that partial substitution of the [BH4]− groups in NaBH4 by BF4− may lead to the formation of distortions within the NaBH4 crystal lattice with favorable channels for Na+ mobility enabling the release of hydrogen at low temperatures.
On‐farm foliar application of a humic biostimulant increases the yield of rice
Authors: Izquierdo Juan , Arriagada Osvin , García‐Pintos Gustavo , Ortiz Rodomiro , García‐Pintos Martín , García‐Pintos Marcelo
Published: July 2024

Biostimulants play a crucial role in enhancing crop yields while promoting sustainability and environmental responsibility. Evaluating the efficacy of biostimulants on‐farm requires rigorous, multiyear trials conducted across various locations and with different cultivars. This study was conducted in Uruguay from 2015 to 2023 to assess the impact of a single application of a humic biostimulant (HB) during the R3 phenological stage on irrigated rice (Oryza sativa L.). The study encompassed 103 farms situated in diverse cropping zones, each characterized by distinct cultivars, soil qualities, radiation, and temperature conditions across the East and North regions. Results revealed that the HB treatment elicited an average yield increase of 7.4% across all sites. Notably, 93% (97) of the trials exhibited a positive yield response, with an average increase of 8.5%, while only six trials (all in the eastern zone) showed a negative response to the HB treatment. A combined analysis of variance indicated that the biostimulant's effect did not significantly differ between production zones, years, or rice cultivars when negative responses were excluded. Furthermore, relationships with environmental variables were nonsignificant, underscoring the positive effect of the biostimulant regardless of location. These findings hold significant implications for Uruguay's rice sector, that is, integrating HBs into standard management practices could substantially boost irrigated rice yields in rice‐producing areas.
Evidence for human‐caused founder effect in populations of Solanum jamesii at archaeological sites: II. Genetic sequencing establishes ancient transport across the Southwest USA
Authors: Pavlik Bruce M. , del Rio Alfonso , Bamberg John , Louderback Lisbeth A.
Published: July 2024

Premise

The domestication of wild plant species can begin with gathering and transport of propagules by Indigenous peoples. The effect on genomic composition, especially in clonal, self‐incompatible perennials would be instantaneous and drastic with respect to new, anthropogenic populations subsequently established. Reductions in genetic diversity and mating capability would be symptomatic and the presence of unique alleles and genetic sequences would reveal the origins and ancestry of populations associated with archaeological sites. The current distribution of the Four Corners potato, Solanum jamesii Torr. in the Southwestern USA, may thus reflect the early stages of a domestication process that began with tuber transport.

Methods

Herein genetic sequencing (GBS) data are used to further examine the hypothesis of domestication in this culturally significant species by sampling 25 archaeological and non‐archaeological populations.

Results

Archaeological populations from Utah, Colorado and northern Arizona have lower levels of polymorphic loci, unique alleles, and heterozygosity than non‐archaeological populations from the Mogollon region of central Arizona and New Mexico. Principle components analysis, Fst values, and structure analysis revealed that genetic relationships among archaeological populations did not correspond to geographic proximity. Populations in Escalante, Utah were related to those on the Mogollon Rim (400 km south) and had multiple origins and significant disjunctions with those populations in Bears Ears, Chaco Canyon, and Mesa Verde sites.

Conclusions

Movement of tubers from the Mogollon region may have occurred many times and in multiple directions during the past, resulting in the complex genetic patterns seen in populations from across the Four Corners region.
American Rhinologic Society expert practice statement part 2: Postoperative precautions and management principles following endoscopic skull base surgery
Authors: Douglas Jennifer E. , Adappa Nithin D. , Choby Garret , Levine Corinna G. , Rabinowitz Mindy R. , Sindwani Raj , Wang Eric W. , Woodworth Bradford A. , Kuan Edward C.
Published: July 2024

The goal of this American Rhinologic Society expert practice statement (EPS) is to summarize the best available evidence regarding postoperative precautions for patients following endoscopic skull base surgery for intradural pathology. These topics include the administration of postoperative nasal hygiene; patient mobilization and activity level; the resumption of continuous positive airway pressure in patients with obstructive sleep apnea; and the timing and capacity with which a patient may be subjected to barotrauma, such as air travel postoperatively. This EPS was developed following the recommended methodology and approval process as previously outlined. Given the diverse practices and limited agreement on the accepted principles regarding postoperative precautions for patients following skull base surgery, this EPS seeks to summarize the existing literature and provide clinically relevant guidance to bring clarity to these differing practice patterns. Following a modified Delphi approach, four statements were developed, all of which reached consensus. Because of the paucity of literature on these topics, these statements represent a summation of the limited literature and the experts’ opinions. These statements and the accompanying evidence are summarized below, along with an assessment of future needs.
Tau‐mediated synaptic dysfunction is coupled with HCN channelopathy
Authors: Goniotaki Despoina , Tamagnini Francesco , Biasetti Luca , Rumpf Svenja‐Lotta , Troakes Claire , Pollack Saskia J. , Ukwesa Shalom , Sun Haoyue , Kraev Igor , Serpell Louise C. , Noble Wendy , Staras Kevin , Hanger Diane P.
Published: July 2024

INTRODUCTION

In tauopathies, altered tau processing correlates with impairments in synaptic density and function. Changes in hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels contribute to disease‐associated abnormalities in multiple neurodegenerative diseases.

METHODS

To investigate the link between tau and HCN channels, we performed histological, biochemical, ultrastructural, and functional analyses of hippocampal tissues from Alzheimer's disease (AD), age‐matched controls, Tau35 mice, and/or Tau35 primary hippocampal neurons.

RESULTS

Expression of specific HCN channels is elevated in post mortem AD hippocampus. Tau35 mice develop progressive abnormalities including increased phosphorylated tau, enhanced HCN channel expression, decreased dendritic branching, reduced synapse density, and vesicle clustering defects. Tau35 primary neurons show increased HCN channel expression enhanced hyperpolarization‐induced membrane voltage “sag” and changes in the frequency and kinetics of spontaneous excitatory postsynaptic currents.

DISCUSSION

Our findings are consistent with a model in which pathological changes in tauopathies impact HCN channels to drive network‐wide structural and functional synaptic deficits.

Highlights

Hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels are functionally linked to the development of tauopathy.

Expression of specific HCN channels is elevated in the hippocampus in Alzheimer's disease and the Tau35 mouse model of tauopathy.

Increased expression of HCN channels in Tau35 mice is accompanied by hyperpolarization‐induced membrane voltage “sag” demonstrating a detrimental effect of tau abnormalities on HCN channel function.

Tau35 expression alters synaptic organization, causing a loosened vesicle clustering phenotype in Tau35 mice.
Metabolic Response to Small Molecule Therapy in Colorectal Cancer Tracked with Raman Spectroscopy and Metabolomics
Authors: Cutshaw Gabriel , Joshi Neeraj , Wen Xiaona , Quam Elizabeth , Bogatcheva Galina , Hassan Nora , Uthaman Saji , Waite Joshua , Sarkar Soumik , Singh Bhuminder , Bardhan Rizia
Published: July 2024

Despite numerous screening tools for colorectal cancer (CRC), 25 % of patients are diagnosed with advanced disease. Novel diagnostic technologies that are early, accurate, and rapid are imperative to assess the therapeutic efficacy of clinical drugs and identify new biomarkers of treatment response. Here Raman spectroscopy (RS) was used to track metabolic reprogramming in KRAS‐mutant HCT116 and SW837 cells, and KRAS wild‐type CC cells. RS combined with multivariate analysis methods distinguished nonresponsive, partially responsive, and responsive cells treated with cetuximab, a monoclonal antibody for EGFR inhibition, sotorasib, a clinically approved KRAS inhibitor, and various doses of trametinib, an inhibitor of the MAPK pathway. Cells treated with a combination of subtoxic doses of trametinib and BKM120, an inhibitor of the PI3K pathway, showed a synergistic response between the two pathways. Using a supervised machine learning regression model, we established a scoring methodology trained to a priori predict therapeutic response to new treatment combinations. RS metabolites were verified with mass spectrometry, and enrichment pathways were identified, including amino acid, purine, and nicotinate and nicotinamide metabolism that differentiated monotherapy from combination therapy. Our approach may ultimately be applicable to patient‐derived primary cells and cultures of patient tumors to predict effective drugs for individualized care.
Mutualistic Synthesis from Orthogonal Dynamic Covalent Reactions
Authors: Lyu Yonglei , Hu Ying , Yang Jinghui , Wang Xin , Li Jianwei
Published: July 2024

Mutualisms are interactions that benefit all species involved. It has been widely investigated in neighbouring subjects, such as biology, ecology, sociology, and economics. However, such a reciprocal relationship in synthetic chemical systems has rarely been studied. Here, we demonstrate a mutualistic synthesis where byproducts from two orthogonal chemical reactions aid each other′s production. Disulfide exchange and hydrazone exchange were chosen to generate two dynamic combinatorial libraries. A minor tetrameric macrocycle from the active disulfide library was quantitatively amplified in the presence of the hydrazone library. This incorporation also turned on the previously inert hydrazone reaction, producing a linear species that formed a “handcuffs” catenane with the disulfide tetramer. These findings not only lend robust support to the hypothesis of “RNA‐peptide coevolution” for the origin of life but also broaden the scope of synthetic chemistry, highlighting the untapped potential of minor products from different reactions. Additionally, the co‐self‐assembly of these mutualistic entities to form supramolecular structures opens new avenues for future development of composite nanosystems with synergistic properties.
Tandem one‐pot synthesis of block copolymers for anion exchange membranes
Authors: Lai Ao Nan , Wang Zhen , Lin Ren Ke , Han Xin Zhi , Zhou Shu Feng
Published: July 2024

The anion exchange membrane (AEM) suffered from poor mechanical properties and low ionic conductivity in fuel cells. Herein, a series of novel block fluorene‐contained poly(arylene ether ketone)s backbones are synthesized by a tandem one‐pot process and then grafted with alkyl chains to form comb‐shaped structure for preparing AEMs. The one‐pot synthesis of block copolymer avoids the multiple purifications of oligomers. The membranes' structure–property relationship is studied by changing the ratios of hydrophilic and hydrophobic segments. The designed comb‐shaped structures grafted on fluorene‐containing block backbones can widen the space between chains and form clear microphase separation patterns, as determined by atomic force microscope (AFM) and small angle x‐ray scattering (SAXS). Hence, resulting AEMs have a high ionic conductivity (117.4 mS cm−1, 80°C). Meanwhile, they also present low swelling rate (SR) from 12.76% to 18.51% at 30°C, 16.84% to 24.36% at 60°C, and 18.33% to 25.81% at 80°C. In addition, excellent mechanical properties, that is, an elongation at break of 29.63% and a tensile strength of 28.72 MPa, are achieved and showed the promise of as‐fabricated AEMs in fuel cell applications.
Dynamic event‐triggered fault identification for nonlinear systems via deterministic learning
Authors: Zeng Chujian , Chen Tianrui , Chen Si‐Zhe , Wu Qiuye
Published: July 2024

In this paper, a fault identification strategy for nonlinear systems is proposed by combining the deterministic learning (DL)‐based adaptive high‐gain observer (AHGO) with a dynamic event‐triggered mechanism (DETM). The DL theory is utilized to satisfy the partial persistent excitation condition, while the AHGO is employed to estimate the system states and fault functions simultaneously. Two DETMs are adopted to reduce data transmission and computational burden. The inter‐event intervals of the considered event‐triggered mechanisms are proven to be positive, thus excluding the Zeno phenomenon. The novelty of this paper lies in that, through the special design of AHGO and event‐triggered conditions, the estimation errors can converge to zero with arbitrary precision. Meanwhile, by incorporating the estimated output error into the DETM design, it is demonstrated that the number of events can be adaptively adjusted based on the fault signal. Furthermore, the relationship between the observer gain and system performance, as well as the inter‐event interval, is revealed (The event‐triggered mechanisms design method that ensures exponential convergence of the observer). Finally, the effectiveness of the developed strategy is verified through a simulation example.
Investigating the physicochemical, antimicrobial and antioxidant properties of chitosan film containing zero‐valent iron nanoparticles and oregano essence
Authors: Khodaparast Farzaneh Khalil , Pirsa Sajad , Toupchi Farzad Mirab , Mohtarami Forogh
Published: July 2024

The problems caused by the pollution of the environment by petroleum polymers in recent years have caused researchers to think of replacing petroleum polymers with biodegradable and natural polymers. The aim of this research was to produce composite film of chitosan (Chit)/zero‐valent iron (Fe) nanoparticles/oregano essence (Ess) (Chit/Fe/Ess). Central composite design was used to study physical, morphological, antioxidant and antimicrobial properties of films. The results showed that with the increase of iron nanoparticles and oregano essence, the thickness of the film increased. The moisture, solubility and water vapor permeability of the film decreased with the increase of iron nanoparticles and oregano essence. The results of the mechanical test showed that with the increase of iron nanoparticles and oregano essence, the tensile strength and elongation at break point decreased. Iron nanoparticles and oregano essence increased significantly the antioxidant activity of the film. The results of the antimicrobial activity of the prepared films show that the addition of iron nanoparticles and oregano essence enhanced the antimicrobial activity of the film against Escherichia coli and Staphylococcus aureus. X‐ray diffraction analysis showed that iron nanoparticles were physically combined with chitosan polymer. Fourier transform infrared (FTIR) results confirmed the physical presence of iron nanoparticles and oregano essence in the polymer matrix. The results of scanning electron microscopy (SEM) showed that the surface of nanocomposite films is more heterogeneous than chitosan. Iron nanoparticles and oregano essence could delay the thermal decomposition of chitosan and increase the thermal stability of chitosan film.