bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of seawater intrusion using 2D electrical imaging
Authors: Nguyen F. , Kemna A. , Antonsson A. , Engesgaard P. , Kuras O. , Ogilvy R. , Gisbert J. , Jorreto S. , Pulido‐Bosch A.
Published: September 2009

We have investigated the potential of 2D electrical imaging for the characterization of seawater intrusion using field data from a site in Almeria, SE Spain. Numerical simulations have been run for several scenarios, with a hydrogeological model reflecting the local site conditions. The simulations showed that only the lower salt concentrations of the seawater‐freshwater transition zone could be recovered, due to the loss of resolution with depth. We quantified this capability in terms of the cumulative sensitivity associated with the measurement setup and showed that the mismatch between the targeted and imaged parameter values occurs from a certain sensitivity threshold. Similarly, heterogeneity may only be determined accurately if located in an adequately sensitive area. At the field site, we identified seawater intrusion at the scale of a few kilometres down to a hundred metres. Borehole logs show a remarkable correlation with the image obtained from surface data but indicate that the electrically derived mass fraction of pure seawater could not be recovered due to the discrepancy between the in‐situ and laboratory‐derived petrophysical relationships. Surface‐to‐hole inversion results suggest that the laterally varying resolution pattern associated with such a setup dominates the image characteristics compared to the laterally more homogeneous resolution pattern of surface only inversion results and hence, surface‐to‐hole images are not easily interpretable in terms of larger‐scale features. Our results indicate that electrical imaging can be used to constrain seawater intrusion models if image appraisal tools are appropriately used to quantify the spatial variation of sensitivity and resolution. The most crucial limitation is probably the apparent non‐stationarity of the petrophysical relationship during the imaging process.
Evidence for composite hydraulic architecture in an active fault system based on 3D seismic reflection, time‐domain electromagnetics and temperature data
Authors: Hess Scott , Fairley Jerry P. , Bradford John , Lyle Mitch , Clement William
Published: September 2009

Fault hydrology is a topic of scientific and practical importance but considerable uncertainty exists regarding the nature of structural controls on fluid flow. Here we use seismic reflection and time‐domain electromagnetic data to develop a three‐dimensional model of hydraulic architecture in a predominantly dip‐slip normal fault system and we predict the architectural elements based on subsurface fluid flow patterns inferred from near‐surface temperature measurements. Our observations indicate the presence of high‐permeability flow paths parallel to fault planes in poorly‐lithified sediments. These results are best explained using a combination of elements from commonly accepted conceptual models of fault architecture, a finding that exhibits the heterogeneous nature of the geologic materials comprising the site. These insights may be useful as a guide to future studies of active fault systems, where multiple‐mode investigations (geophysical, hydrologic, thermal, geochemical) will be required to better understand subsurface fluid/fault interactions.
Numerical modelling of the IP effect at the pore scale
Authors: Blaschek R. , Hördt A.
Published: September 2009

Geophysicists have tried for a long time to correlate induced polarization data with parameters of the pore geometry, often with the overall aim to estimate the important parameter of hydraulic conductivity. However, no correlation has been found so far that is applicable to more than just a few special cases. Using empirical relationships and equivalent circuits often neglects the description of the processes in the pore space. One reason is that the mechanisms controlling the low‐frequency polarization are still not completely understood. Only a few existing models try to explain the processes and derive relationships with geometry and most models need strong assumptions. Here, we aim at a deeper understanding by numerical modelling of the main processes responsible for the IP effect. Our approach is based on a 1D solution of the late 1950s that gives an expression for the maximum frequency effect for simplified geometries. The models depend on the lengths of active and passive zones and the corresponding ion mobilities in each zone for anions and cations respectively. The theory describes the ion diffusion along concentration gradients, the influence of an external electric field and the coupling between the two.

We first verify our numerical results by comparison with analytical solutions and then extend the approach to flexible geometry, including higher dimension. This constitutes a considerable progress from 1D models restricted to two alternating media with fixed lengths. Apart from arbitrary geometry, we can also simulate the full spectral behaviour. A relatively simple model is able to explain frequency‐dependent magnitude and phase behaviour that is typically measured in the field. The Cole‐Cole model can be considered as the result of a network of pores of varying lengths. From our modelling studies, we derive scaling laws for mobility and geometry and suggest an empirical equation for the relationship between the length of passive pores and the time of maximum phase shift.
Integrated management and utilization of hydrogeophysical data on a national scale
Authors: Møller Ingelise , Søndergaard Verner H. , Jørgensen Flemming , Auken Esben , Christiansen Anders V.
Published: September 2009

Development of more time‐efficient and airborne geophysical data acquisition systems during the past decades have made large‐scale mapping attractive and affordable in the planning and administration of e.g., groundwater resources or raw material deposits. The handling and optimized use of large geophysical data sets covering large geographic areas requires a system that allows data to be easily stored, extracted, interpreted, combined and used one time after another with different purposes. Such an integrated system for management and utilization of hydrogeophysical data on a national scale has been developed during the past decade in Denmark.

This data handling system includes a comprehensive national geophysical data base (the GERDA data base), a national data base for borehole information (the Jupiter data base), a program package for processing, interpretation and visualization of electrical and electromagnetic data as well as preparation of these data for upload to the geophysical data base (the Aarhus Workbench) and finally a 3D visualization and modelling tool used for geological modelling and data quality control. The Aarhus Workbench program package allows visualization and analysis of subsets of data from the geophysical data base, which may include data from many individual mapping campaigns. The 3D visualization and modelling tool uses data from the geophysical and the borehole data bases directly; moreover, it handles maps and grids produced in the Aarhus Workbench.

The integrated system for management of hydrogeophysical data allows management of large amounts of data collected over several years in different mapping campaigns, of different consultant companies and with different geophysical methods and instrumentation. It is now used by all partners involved in the groundwater mapping in Denmark. The system promotes reuse of geophysical data and models in future mapping projects, as well as easing and promoting the use of geophysical data in the geological modelling. The integrated system secures transfer of documentation all the way from data acquisition over processing and inversion of the geophysical data to geological modelling through storage of data acquisition parameters, data processing parameters, inversion parameters and uncertainties on data and models in the geophysical data base.

The benefits of the large amount of geophysical data gathered in the national geophysical data base and utilized by the two program packages are invaluable for all future groundwater planning and administration.
Ecohydrogeophysics at the Edwards Aquifer: insights from Polarimetric ground‐penetrating radar
Authors: Sassen Douglas S. , Everett Mark E. , Munster Clyde L.
Published: September 2009

Three‐dimensional multicomponent ground‐penetrating radar (GPR) reflection data and horizontal GPR transmission profiles were acquired and analyzed to better understand the interaction of vegetation with subsurface flow conduits at a hydrologic experimentation site. Previous researchers conducted a set of shallow (<2.5 m) subsurface hydrology experiments during simulated rainfall events within a small plot (7 m × 14 m) on the fractured and karsted limestone of the Edwards Aquifer region near San Antonio, Texas, USA, to better understand the influence of Juniperus ashei brush control on the local hydrology. Tracer experiments showed a high degree of variability in tracer recovery, advection speed and concentration depending on the location of the application of the tracer. Both 3D multicomponent GPR reflection images and coherency and inversion of GPR horizontal transmission profiles were utilized to identify the main conduits of flow within the experimentation site in order to explain the observations of the experiments. The 3D multicomponent GPR and coherency images revealed that the most obvious potential conduits run nearly parallel with the observation trench. Inversions of the horizontal transmission profiles indicate that some conduits are filled with soil while others have no fill. This information helps explain the high spatiotemporal variability observed in the tracer data. Additionally, the GPR and hydrologic experiments suggest that Juniperus ashei significantly impacts infiltration by redirecting flow towards its roots occupying fractures within the rock. This study demonstrates that GPR provides a noninvasive tool that can improve future subsurface ecohydrologic experimentation.
Hydrogeological prospecting using P‐ and S‐wave landstreamer seismic reflection methods
Authors: Pugin André J.‐M. , Pullan Susan E. , Hunter James A. , Oldenborger Greg A.
Published: September 2009

We present two case histories from different areas and geological settings in Canada where we have used a vibrating seismic source coupled to a landstreamer receiver array in hydrogeological investigations related to aquifers in glacial sediments. In Manitoba, our P‐wave seismic reflection profiles are used to provide an assessment of the subsurface architecture of buried valleys, estimate the thickness and properties of both the channel fill and the overlying sediments to depths of ~100 m and locate optimum sites for groundwater well placements. In eastern Ontario, we collected P‐ and S‐wave seismic reflection as well as electrical resistivity data to investigate buried esker aquifers. The geophysical data provide detailed high‐resolution information (to ~30 m depth) on the structure of the esker core and its overlying sand cover and on the thickness and variability of the overlying fine‐grained aquitard. The data presented in this paper demonstrate that shallow seismic reflection methods are very effective tools to explore, assess and evaluate groundwater reservoirs and resources. The recent advent of landstreamer receiver arrays, especially when coupled to a vibratory seismic source, makes these methods significantly more cost‐effective and efficient. We now routinely collect ~1000 records/day, or 1.5‐6 line‐km/day, using our Minivib/landstreamer data acquisition system. With this type of efficient data collection, it is anticipated that the use of shallow seismic reflection methods in hydrogeological prospecting will increase as groundwater and its protection become more valued by society.
Monitoring freshwater‐seawater interface dynamics with audiomagnetotelluric data
Authors: Falgàs Ester , Ledo Juanjo , Marcuello Alex , Queralt Pilar
Published: September 2009

Saltwater intrusion is one of the main environmental concerns within coastal aquifers. In this study we test the audiomagnetotelluric (AMT) method as a technique that can detect changes in electrical resistivity as a result of seasonal groundwater salinity changes. AMT is a frequency domain electromagnetic induction technique ideally suited for hydrogeophysical investigations at the basin scale, specifically in low resistivity environments such as saltwater encroachments areas. We present numerical seawater intrusion models to explore the effects of saline content variability on the model resolution. Survey data were also acquired during a long‐term AMT monitoring experiment in a natural condition aquifer system and these results were compared to the numerical modelling results. The aquifer system is located in the deltaic zone of the Tordera River (north‐eastern of Iberian Peninsula), where a main paleochannel that works as a seawater intrusion path was already identified in previous studies. Every four months, between 2004 and 2006, seven AMT soundings were recorded along a 1700 m long profile over the paleochannel. The final models reveal dynamic changes in the seawater‐freshwater interface that correspond directly with the hydrologic state of the aquifer system.
The geophysical investigation of lake water seepage in the regulated environment of the Bosherston Lily Ponds, South Wales, UK. Part 1: natural, fracture‐related pathways
Authors: Husband Claire R. , Cassidy Nigel J. , Stimpson Ian G.
Published: September 2009

The detection and characterization of hydrological pathways is applicable to many branches of geosciences including contaminant hydrogeology, mining, civil engineering and petroleum geology. Geological features play a critical role in fluid transportation through the presence of enhanced hydraulic conductivity pathways, although determining their exact contribution is difficult. This paper reports the results of geophysical investigations at the Bosheston Lily Ponds in Pembroke, South Wales, UK where the lake system has experienced unexplained water loss for over thirty years. The area is classified a Special Area of Conservation (SAC) and is managed under tight regulatory regime that limits the scope and extent of any site investigations. Geophysical surveys focused on identifying any natural hydraulic conduits/pathways in the underlying carboniferous limestone where the main objectives were to determine whether bedrock fracturing is promoting natural water loss. Ground‐penetrating radar (GPR), electrical resistance tomography (ERT) and self‐potential (SP) surveys were collected at targeted site locations and the information gained used to ascertain the nature of the observed/predicted lake water loss. The results show that localized zones of high‐density, small‐scale fracturing in the limestone bedrock are likely to be the predominant cause of lake water loss with little evidence of larger scaled, open karstic features.
A review of helicopter‐borne electromagnetic methods for groundwater exploration
Authors: Siemon Bernhard , Christiansen Anders Vest , Auken Esben
Published: September 2009

For about three decades, airborne electromagnetic (AEM) systems have been used for groundwater exploration purposes. Airborne systems are appropriate for large‐scale and efficient groundwater surveying. Due to the dependency of the electrical conductivity on both the clay content of the host material and the mineralization of the water, electromagnetic systems are suitable for providing information about the aquifer structures and water quality, respectively.

More helicopter than fixed‐wing systems are used in airborne groundwater surveys. Helicopter‐borne frequency‐domain electromagnetic (HEM) systems use a towed rigid‐boom. Helicopter‐borne time‐domain (HTEM) systems, which use a large transmitter loop and a small receiver within or above the transmitter, are generally designed for mineral exploration purposes but recent developments have made some of these systems usable for groundwater purposes as well.

The quantity measured, the secondary magnetic field, depends on the subsurface conductivity distribution. Due to the skin‐effect, the penetration depths of the AEM fields depend on the system characteristics used: high‐frequency data/early‐time channels describe the shallower parts of the conducting subsurface and the low‐frequency data/late‐time channels the deeper parts. Typical investigation depths range from some ten metres (conductive grounds) to several hundred metres (resistive grounds), where the HEM systems are appropriate for shallow to medium deep (about 1–100 m) and the HTEM systems for medium deep to deep (about 10–400 m) investigations.

Generally, the secondary field values are inverted into resistivities and depths using homogeneous or layered half‐space models. As the footprint of AEM systems is rather small, one‐dimensional interpretation of AEM data is sufficient in most cases and single‐site inversion procedures are widely used. Laterally constrained inversion of AEM data often improves the stability of the inversion models, particularly for noisy data. Higher dimensional inversion is still not possible for standard‐size surveys.

Based on typical field examples the advantages as well as the limitations of AEM surveys compared to long‐established ground‐based geophysical methods used in groundwater surveys are discussed. In a case history from a German island an airborne frequency‐domain system is used to successfully locate freshwater lenses on top of saltwater. An example from Denmark shows how a time‐domain system is used to locate large‐scale buried structures forming ideal groundwater aquifers.
The geophysical investigation of lake water seepage in the regulated environment of the Bosherston Lily Ponds, South Wales, UK. Part 2: historical, dam‐related pathways
Authors: Husband Claire R. , Cassidy Nigel J. , Stimpson Ian G.
Published: September 2009

The detection, characterization and assessment of water loss through hydrological pathways is an important aspect of civil, hydrological and environmental engineering. At any site, variations in the form and hydrological integrity of both natural and man‐made features can play a critical role in fluid transportation through the presence of enhanced hydraulic conductivity. Traditional hydrological and invasive engineering investigation methods are often unsuitable for ecologically sensitive environments and in this paper, we report the results of a non‐invasive hydro‐geophysical study at the Bosheston Lily Ponds in Pembroke, South Wales, UK, an area classified a Special Area of Conservation (SAC). For over 30 years, the lake system has experienced unexplained water loss and the geophysical surveys focused on identifying hydraulic conduits/pathways in the underlying carboniferous limestone and assessing the integrity of the man‐made dam structure at the outlet of the lake system. The site is managed under tight regulatory regime that limits the scope and extent of any hydrological/geophysical investigations. The main objectives were to determine whether bedrock fracturing is promoting natural water loss and, more pertinently, if structural failures in the modern (and original) dam structures were responsible for significant loss of water at the outlet of the lakes. Ground‐penetrating radar (GPR), electrical resistance tomography (ERT) and self‐potential (SP) surveys were collected at targeted sites and the information gained used to ascertain the nature of the observed/predicted lake water loss. The results show that both the modern and original dam appear to be intact, structurally sound and show no evidence for significant water flow through its structures. Instead, localized zones of natural, high‐density fracturing in the limestone bedrock appear to be the predominant cause of lake water loss.
Fast, laterally smooth inversion of airborne time‐domain electromagnetic data
Authors: Christensen Niels B. , Reid James E. , Halkjær Max
Published: September 2009

We present a fully developed, fast approximate method for 1D inversion of time‐domain electromagnetic data. The method is applied to a helicopterborne transient electromagnetic data set from the Toolibin Lake area of Western Australia using the lateral parameter correlation method to ensure lateral smoothness of the inverted models.

The method is based on fast approximate forward computation of transient electromagnetic step responses and their derivatives with respect to the model parameters of a 1D model. The inversion is carried out with multi‐layer models in an iterative, constrained least‐squares inversion formulation including explicit formulation of the model regularization through a model covariance matrix. The method is 50 times faster than conventional inversion for a layered earth model and produces model sections of concatenated 1D models and contoured maps of mean conductivity in depth intervals almost indistinguishable from those of conventional inversion.

To ensure lateral smoothness of the model sections and to avoid spurious artefacts in the mean conductivity maps, the inversion is integrated with the lateral parameter correlation method. In this way, well determined parameters are allowed to influence the more poorly determined parameters in the survey area.

Applied to the Toolibin data set, the inversion produces model sections and conductivity maps that reveal the distribution of conductivity in the area and thereby the distribution of salinity. This information is crucial for any remediation effort aimed at alleviating the salinization problems.
Development of a holistic wellness model for managers in tertiary institutions
Authors: Botha Petrus A. , Brand Hein
Published: September 2009

Individuals struggle to attain optimal wellness and health  levels due to unhealthy lifestyle behaviour. A holistic wellness model was developed in this study to provide a framework for a cross-sectional survey to assess the wellness behaviour and health risk levels of managers in two South African universities. A census was done on the total population of 324 and responses were received from 89 managers. The study employed descriptive and inferential statistical procedures to analyse  the quantitative data. The findings  suggested  that  the managers had high levels of  wellness behaviour and low levels of health risks. Physical fitness and nutrition as well as medical self-care wellness behaviour  levels were  identified as weaknesses among managers, for which urgent interventions are required.
Scutellarin Attenuates Microglia Activation in LPS‐Induced BV‐2 Microglia via miRNA‐7036a/MAPT/PRKCG/ERK Axis
Authors: Duan Zhaoda , Yang Li , Xu Dongyao , Qi Zhi , Jia Wenji , Wu Chunyun
Published: April 2024

Scutellarin is an herbal agent which can exert anti‐neuroinflammatory effects in activated microglia. However, it remains uncertain if it can inhibit microglia‐mediated neuroinflammation by regulating miRNAs. This study sought to elucidate the upstream regulatory mechanisms by endogenous microRNAs and its target gene in activated microglia in lipopolysaccharide (LPS)‐induced BV‐2 microglia. Results show that scutellarin suppressed the expression of tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β), and inducible nitric oxide synthase (iNOS) significantly in LPS‐stimulated BV‐2 microglia. As with the results of miRNAs function classification in vitro, the expression levels of mir‐7036a‐5p are upregulated in LPS‐activated BV‐2 microglia, but are downregulated by scutellarin. Rescue experiments indicated that mir‐7036a‐5p is a pro‐inflammatory factor in activated BV‐2 microglia. mir‐7036a‐5p agomir promoted the expression of phosphorylated tau proteins (p‐tau), protein kinase C gamma type (PRKCG), extracellular regulated protein kinases (ERK1/2), but the is reversed by mir‐7036a‐5p antagomir in vitro. It is shown here that mir‐7036a‐5p is involved in microglia‐mediated inflammation in LPS‐induced BV‐2 microglia. More important is the novel finding that scutellarin mitigated microglia inflammation by down‐regulating the mir‐7036a‐5p/MAPT/PRKCG/ERK signaling pathway.
Tissue‐Engineered Microvessels: A Review of Current Engineering Strategies and Applications
Authors: Zhao Nan , Pessell Alexander F. , Zhu Ninghao , Searson Peter C.
Published: April 2024

Microvessels, including arterioles, capillaries, and venules, play an important role in regulating blood flow, enabling nutrient and waste exchange, and facilitating immune surveillance. Due to their important roles in maintaining normal function in human tissues, a substantial effort has been devoted to developing tissue‐engineered models to study endothelium‐related biology and pathology. Various engineering strategies have been developed to recapitulate the structural, cellular, and molecular hallmarks of native human microvessels in vitro. In this review, recent progress in engineering approaches, key components, and culture platforms for tissue‐engineered human microvessel models is summarized. Then, tissue‐specific models, and the major applications of tissue‐engineered microvessels in development, disease modeling, drug screening and delivery, and vascularization in tissue engineering, are reviewed. Finally, future research directions for the field are discussed.
Bioactive Profiling, Antibacterial Efficacy and Computational Modelling of Myrtus Communis Essential Oil (Morocco)
Authors: Hayani Mouhcine , Benabbouha Tariq , Naceiri Mrabti Nidal , Eljebri Said , Sabiri Maryame , Zair Touriya
Published: April 2024

In the context of investigations into molecules of natural origin with biological activities. This study focuses on the development of Myrtus communis L., a medicinal plant found in the mountains of Morocco. The first, an analysis carried out on leaves using the inductively coupled plasma spectrometry technique, showed the almost total absence of heavy metals. Furthermore, we aim to identify the chemical composition of its essential oils by gas chromatography‐mass spectrometry (GC/MS) analysis and assess its antibacterial efficacy in vitro and in silico. The average yield of essential oils was 0.9 %±0.06, and GC/MS analysis identified 35 constituents, with myrcene (27,38 %), limonene (16,51 %), α‐pinene (7,32 %) being the major compounds. Remarkably, the essential oils displayed considerable antibacterial activity against various tested bacteria, including Escherichia coli (0.7 μL/mL), Escherichia pseudocoloides (2.8 μl/ml), Escherichia vekanda (2.8 μl/ml). Molecular docking has contributed to our understanding of the mechanism of antibacterial action of the main compounds in this essential oil.
Challenges in Measuring Transport Parameters of Carbonate‐Based Electrolytes
Authors: Lehnert Lukas , Nojabaee Maryam , Latz Arnulf , Horstmann Birger
Published: April 2024

Numerical simulations are a powerful tool for the development and improvement of Li‐ion batteries. Modeling the mass transport of the involved electrolytic solutions requires precise determination of the corresponding electrolyte parameters. In this work, we attempt to measure the conductivity, the diffusion coefficient, the transference number and the thermodynamic factor for a system of 0.5 M LiPF6 dissolved in a blend of ethylene carbonate and ethyl methyl carbonate (EC : EMC, 3 : 7 weight) at 20 °C and 50 °C. Applying galvanostatic polarization experiments to symmetrical Li metal | electrolyte+separator | Li metal cells reveals, however, a potential response qualitatively deviating from theoretical expectations. Impeded diffusion processes indicate the presence of additional, undesired porous structures on the Li electrodes, preventing a reliable evaluation of the electrolyte parameters. To spectrally resolve the diffusive processes, we conduct very‐low‐frequency impedance spectroscopy. The impedance in fact exhibits multiple interfering diffusive features. In our measurements, an explicit identification of the impedance for the sole diffusion through the separator is however not feasible. Therefore, the authors doubt that polarizing experiments using Li metal electrodes yield accurate parameters for electrolytes.
Defect Engineering in Bi‐Based Photo/Electrocatalysts for Nitrogen Reduction to Ammonia
Authors: Lv Shuhua , Wang Ying , Wang Debao , Song Caixia
Published: April 2024

Main group Bi‐based materials have gained popularity as N2 reduction reaction (NRR) photo/electrocatalysts due to their ability to inhibit competitive H2 evolution reactions (HER) and the unique N2 adsorption activities. The introduction of defects in Bi‐based catalysts represents a highly effective strategy for enhancing light absorption, promoting efficient separation of photogenerated carriers, optimizing the activity of free radicals, regulating electronic structure, and improving catalytic performance. In this review, we outline the various applications of state of the defect engineering in Bi‐based catalysts and elucidate the impact of vacancies on NRR performance. In particular, the types of defects, methods of defects tailoring, advanced characterization techniques, as well as the Bi‐based catalysts with abundant defects and their corresponding catalytic behavior in NRR were elucidated in detail. Finally, the main challenges and opportunities for future development of defective Bi‐based NRR catalysts are discussed, which provides a comprehensive theoretical guidance for this field.
Tartaric Acid Cross‐Linking Polyvinyl Alcohol as Degradable Separators for Rechargeable Lithium Ion Batteries
Authors: Yuan Huimin , Liu Kun , Luo Wen , Wang Zhiqiang , Yan Chunliu , Hu Jing , Wang Xinyang , Liu Guiyu , Xu Zhenghe , Lu Zhouguang
Published: April 2024

The escalating focus on environmental concerns and the swift advancement of eco‐friendly biodegradable batteries raises a pressing demand for enhanced material design in the battery field. The traditional polypropylene (PP) that is monopolistically utilized in the commercial LIBs is hard to recycle. In this work, we prepare a novel water degradable separators via the cross‐linking of polyvinyl alcohol (PVA) and dibasic acid (tartaric acid, TA). Through the integration of non‐solvent liquid‐phase separation, we successfully produced a thermally stable PVA‐TA membrane with tunable thickness and a high level of porosity. These specially engineered PVA‐TA separators were implemented in LiFePO4 (LFP)|separator|Li cells, resulting in superior multiplicative performance and achieving a capacity of 88 mAh g−1 under 5 C. Additionally, the straightforward small molecule cross‐linking technique significantly reduced the crystalline region of the polymer, thereby enhancing ionic conductivity. Notably, after cycling, the PVA‐TA separators can be easily dissolved in 95 °C hot water, enabling its reutilization for the production of new PVA‐TA separators. Therefore, this work introduces a novel concept to design green and sustainable separators for recyclable lithium batteries.
Enhancing Electrochemical Performance of Aluminum‐Ion Batteries with Fluorinated Graphene Cathode
Authors: Lei Haiping , Wei Tianwei , Tu Jiguo , Li Suqin , Jiao Shuqiang
Published: April 2024

In pursuit of high‐performance aluminum‐ion batteries, the selection of a suitable positive electrode material assumes paramount importance, and fluorinated graphene (FG) nanostructures have emerged as an exceptional candidate. In the scope of this study, a flexible tantalum foil is coated with FG to serve as the positive electrode for aluminum‐ion batteries. FG positive electrode demonstrates a remarkable discharge capacity of 109 mA h g−1 at a current density of 200 mA g−1, underscoring its tremendous potential for energy storage applications. Concurrently, the FG positive electrode exhibits a discharge capacity of 101 mA h g−1 while maintaining an impressive coulombic efficiency of 95 % over 300 cycles at a current density of 200 mA g−1, which benefiting from the significant structure of FG. The results of the in‐situ Raman spectroscopy signified the presence of intercalation/de‐intercalation processes of AlCl4− behavior within the FG layers.
Design, synthesis, and biological evaluation of dinaciclib and CAN508 hybrids as CDK inhibitors
Authors: Odeh Dana M. , Allam Heba Abdelrasheed , Baselious Fady , Mahmoud Walaa R. , Odeh Mohanad M. , Ibrahim Hany S. , Abdel‐Aziz Hatem A. , Mohammed Eman R.
Published: April 2024

The scaffolds of two known CDK inhibitors (CAN508 and dinaciclib) were the starting point for synthesizing two series of pyarazolo[1,5‐a]pyrimidines to obtain potent inhibitors with proper selectivity. The study presented four promising compounds; 10d, 10e, 16a, and 16c based on cytotoxic studies. Compound 16a revealed superior activity in the preliminary anticancer screening with GI % = 79.02–99.13 against 15 cancer cell lines at 10 μM from NCI full panel 60 cancer cell lines and was then selected for further investigation. Furthermore, the four compounds revealed good safety profile toward the normal cell lines WI‐38. These four compounds were subjected to CDK inhibitory activity against four different isoforms. All of them showed potent inhibition against CDK5/P25 and CDK9/CYCLINT. Compound 10d revealed the best activity against CDK5/P25 (IC50 = 0.063 µM) with proper selectivity index against CDK1 and CDK2. Compound 16c exhibited the highest inhibitory activity against CDK9/CYCLINT (IC50 = 0.074 µM) with good selectivity index against other isoforms. Finally, docking simulations were performed for compounds 10e and 16c accompanied by molecular dynamic simulations to understand their behavior in the active site of the two CDKs with respect to both CAN508 and dinaciclib.
Endoscopic assessment of the J pouch in ulcerative colitis: A narrative review
Authors: Akiyama Shintaro , Barnes Edward L , Onoda Tsubasa , Ishikawa Naoki , Shiroyama Mamiko , Ito Yuka , Rubin David T , Tsuchiya Kiichiro
Published: April 2024

Patients with ulcerative colitis sometimes need a total colectomy with ileal pouch‐anal anastomosis due to medically refractory disease or colitis‐associated neoplasia. Up to 50% of patients with ulcerative colitis postoperatively develop pouchitis and the rate of chronic inflammatory pouch conditions requiring pouch excision or diverting ileostomy is reported to be 10%. In order to diagnose and monitor pouchitis, pouchoscopy is essential to assess endoscopic inflammatory findings of the J pouch and to survey neoplasia development, particularly in the remnant distal rectum. However, endoscopic protocols for the evaluation of the pouch may not be standardized worldwide and the reliability of existing disease activity indices for pouchitis has been questioned due to the lack of validation. Recently, reliable endoscopic scoring systems based on an observation of the anatomical location of the J pouch were reported and a significant association between the distribution pattern of endoscopic inflammation (i.e., endoscopic phenotype) and pouch outcomes was also uncovered. In this review, we discuss how to survey the J pouch using pouchoscopy, endoscopic indices for pouchitis disease activity, endoscopic phenotypes and classification, and the pathological mechanisms of pouchitis phenotype in patients with ulcerative colitis.
Allometric relationships and trade‐offs in 11 common Mediterranean‐climate grasses
Authors: Gao Xiulin , Koven Charles D. , Kueppers Lara M.
Published: April 2024

Biomass allocation in plants is the foundation for understanding dynamics in ecosystem carbon balance, species competition, and plant–environment interactions. However, existing work on plant allometry has mainly focused on trees, with fewer studies having developed allometric equations for grasses. Grasses with different life histories can vary in their carbon investment by prioritizing the growth of specific organs to survive, outcompete co‐occurring plants, and ensure population persistence. Further, because grasses are important fuels for wildfire, the lack of grass allocation data adds uncertainty to process‐based models that relate plant physiology to wildfire dynamics. To fill this gap, we conducted a greenhouse experiment with 11 common California grasses varying in photosynthetic pathway and growth form. We measured plant sizes and harvested above‐ and belowground biomass throughout the life cycle of annual species, while for the establishment stage of perennial grasses to quantify allometric relationships for leaf, stem, and root biomass, as well as plant height and canopy area. We used basal diameter as a reference measure of plant size. Overall, basal diameter is the best predictor for leaf and stem biomass, height, and canopy area. Including height as another predictor can improve model accuracy in predicting leaf and stem biomass and canopy area. Fine root biomass is a function of leaf biomass alone. Species vary in their allometric relationships, with most variation occurring for plant height, canopy area, and stem biomass. We further explored potential trade‐offs in biomass allocation across species between leaf and fine root, leaf and stem, and allocation to reproduction. Consistent with our expectation, we found that fast‐growing plants allocated a greater fraction to reproduction. Additionally, plant height and specific leaf area negatively influenced the leaf‐to‐stem ratio. However, contrary to our hypothesis, there were no differences in root‐to‐leaf ratio between perennial and annual or C4 and C3 plants. Our study provides species‐specific and functional‐type‐specific allometry equations for both above‐ and belowground organs of 11 common California grass species, enabling nondestructive biomass assessment in California grasslands. These allometric relationships and trade‐offs in carbon allocation across species can improve ecosystem model predictions of grassland species interactions and environmental responses through differences in morphology.
Ecology of fear alters behavior of grizzly bears exposed to bear‐viewing ecotourism
Authors: Short Monica L. , Service Christina N. , Suraci Justin P. , Artelle Kyle A. , Field Kate A. , Darimont Chris T.
Published: April 2024

Humans are perceived as predators by many species and may generate landscapes of fear, influencing spatiotemporal activity of wildlife. Additionally, wildlife might seek out human activity when faced with predation risks (human shield hypothesis). We used the anthropause, a decrease in human activity resulting from the COVID‐19 pandemic, to test ecology of fear and human shield hypotheses and quantify the effects of bear‐viewing ecotourism on grizzly bear (Ursus arctos) activity. We deployed camera traps in the Khutze watershed in Kitasoo Xai'xais Territory in the absence of humans in 2020 and with experimental treatments of variable human activity when ecotourism resumed in 2021. Daily bear detection rates decreased with more people present and increased with days since people were present. Human activity was also associated with more bear detections at forested sheltered sites and less at exposed sites, likely due to the influence of habitat on bear perception of safety. The number of people negatively influenced adult male detection rates, but we found no influence on female with young detections, providing no evidence that females responded behaviorally to a human shield effect from reduced male activity. We also observed apparent trade‐offs of risk avoidance and foraging. When salmon levels were moderate to high, detected bears were more likely to be females with young than adult males on days with more people present. Should managers want to minimize human impacts on bear activity and maintain baseline age–sex class composition at ecotourism sites, multiday closures and daily occupancy limits may be effective. More broadly, this work revealed that antipredator responses can vary with intensity of risk cues, habitat structure, and forage trade‐offs and manifest as altered age–sex class composition of individuals using human‐influenced areas, highlighting that wildlife avoid people across multiple spatiotemporal scales.
Neural substrates of affective temperaments: An intersubject representational similarity analysis to resting‐state functional magnetic resonance imaging in nonclinical subjects
Authors: Qiu Yidan , Wu Xiaoyan , Liu Bingyi , Huang Ruiwang , Wu Huawang
Published: April 2024

Previous research has suggested that certain types of the affective temperament, including depressive, cyclothymic, hyperthymic, irritable, and anxious, are subclinical manifestations and precursors of mental disorders. However, the neural mechanisms that underlie these temperaments are not fully understood. The aim of this study was to identify the brain regions associated with different affective temperaments. We collected the resting‐state functional magnetic resonance imaging (fMRI) data from 211 healthy adults and evaluated their affective temperaments using the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire. We used intersubject representational similarity analysis to identify brain regions associated with each affective temperament. Brain regions associated with each affective temperament were detected. These regions included the prefrontal cortex, anterior cingulate cortex (ACC), precuneus, amygdala, thalami, hippocampus, and visual areas. The ACC, lingual gyri, and precuneus showed similar activity across several affective temperaments. The similarity in related brain regions was high among the cyclothymic, irritable, and anxious temperaments, and low between hyperthymic and the other affective temperaments. These findings may advance our understanding of the neural mechanisms underlying affective temperaments and their potential relationship to mental disorders and may have potential implications for personalized treatment strategies for mood disorders.
Early intervention and care for Diabetic Foot Ulcers in Low and Middle Income Countries: Addressing challenges and exploring future strategies: A narrative review
Authors: Swaminathan Niranjna , Awuah Wireko Andrew , Bharadwaj Hareesha Rishab , Roy Sakshi , Ferreira Tomas , Adebusoye Favour Tope , Ismail Isma Farah Nurlisa binti , Azeem Saleha , Abdul‐Rahman Toufik , Papadakis Marios
Published: April 2024

Background and Aims

Diabetic Foot Ulcers (DFUs) are a significant health concern, particularly in Low‐ and Middle‐Income Countries (LMICs). This review explores key strategies for managing DFUs in LMICs, including integrating podiatry, endocrinology, and wound care services, educating patients, promoting self‐care, and preventive measures to reduce amputation rates.

Methods

A comprehensive literature review was conducted, focusing on studies conducted in Low and Middle Income Countries to facilitate a qualitative analysis. The review examined the aetiology and risk factors to developing DFUs, clinical presentation, multidisciplinary management and evidence based interventions, challenges to the provision of care and future directions, all pertaining to DFUs in low and middle income countries.

Results

The aetiology and risk factors contributing to the development of DFUs are complex and multifaceted. Factors such as limited access to health care, inadequate diabetes management, and socioeconomic disparities significantly influence the incidence of DFUs. Clinical presentation varies, with patients often presenting at advanced stages of the disease due to delayed or missed diagnoses. Multidisciplinary management, incorporating podiatry, endocrinology, and wound care services, has exhibited substantial promise in enhancing patient outcomes. Evidence‐based interventions, including offloading techniques, wound debridement, and the use of advanced wound dressings, have proven effective in promoting ulcer healing.

Conclusion

The burden of DFUs in LMICs requires comprehensive strategies. Integrating podiatry, endocrinology, and wound care services, along with patient education and self‐care practices, is essential for reducing amputations and improving patients' quality of life. Regular follow‐up and early detection are vital for effective DFU management, emphasizing the need for ongoing research and investment in LMIC health care infrastructure. Embracing these multidisciplinary, patient‐centered approaches can effectively address the challenge of DFUs in LMICs, leading to better patient outcomes and improved quality of life.
Transcriptomic analysis reveals the crosstalk between type 2 diabetes and chronic pancreatitis
Authors: Chen Youlan , Hao Lixiao , Cong Jun , Ji Jianmei , Dai Yancheng , Xu Li , Gong Biao
Published: April 2024

Background and Aims

Mounting evidence highlights a strong association between chronic pancreatitis (CP) and type 2 diabetes (T2D), although the exact mechanism of interaction remains unclear. This study aimed to investigate the crosstalk genes and pathogenesis between CP and T2D.

Methods

Transcriptomic gene expression profiles of CP and T2D were extracted from Gene Expression Omnibus, respectively, and the common differentially expressed genes (DEGs) were subsequently identified. Further analysis, such as Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein–protein interaction, transcription factors (TFs), microRNA (miRNAs), and candidate chemicals identification, was performed to explore the possible common signatures between the two diseases.

Results

In total, we acquired 281 common DEGs by interacting CP and T2D datasets, and identified 10 hub genes using CytoHubba. GO and KEGG analyses revealed that endoplasmic reticulum stress and mitochondrial dysfunction were closely related to these common DEGs. Among the shared genes, EEF2, DLD, RAB5A, and SLC30A9 showed promising diagnostic value for both diseases based on receiver operating characteristic curve and precision‐recall curves. Additionally, we identified 16 key TFs and 16 miRNAs that were strongly correlated with the hub genes, which may serve as new molecular targets for CP and T2D. Finally, candidate chemicals that might become potential drugs for treating CP and T2D were screened out.

Conclusion

This study provides evidence that there are shared genes and pathological signatures between CP and T2D. The genes EEF2, DLD, RAB5A, and SLC30A9 have been identified as having the highest diagnostic efficiency and could be served as biomarkers for these diseases, providing new insights into precise diagnosis and treatment for CP and T2D.
How underinvestment reduces underpricing
Authors: Bade Marco , Hirth Hans
Published: April 2024

We develop an economic model demonstrating that firms can benefit from committing to underinvestment. The model considers a firm's IPO, secondary‐market trading and subsequent investment decision. We analyse the conditions under which underinvestment can paradoxically be advantageous despite reducing the fundamental value of the firm. The benefit of committing to underinvest post‐IPO is expressed in reduced underpricing and thus a higher valuation during the IPO. We furthermore show that the firm may commit to an inefficient investment policy by appointing a manager with biased expectations or risk aversion. Our findings imply that, under certain conditions, firms are better off relying on biased managers when their initial outlook is poor, but risk‐averse managers when their initial outlook is good.
Using atomic clustering based on structural and electronic descriptors that consider surrounding environment to evaluate local properties of DFT functionals
Authors: Nakajima Yuya , Ohmura Takuto , Seino Junji
Published: April 2024

We developed a method for evaluating the accuracies of the local properties of DFT functionals in detail using a clustering method based on machine learning and structural/electronic descriptors. We generated 36 clusters consistent with human intuition using 30,436 carbon atoms from the QM9 dataset. The results were used to evaluate 13C NMR chemical shifts calculated using 84 DFT functionals. Carbon atoms were grouped based on their similar environments, reducing errors within these groups. This enables more accurate assessment of the accuracy using a specific DFT functional. Therefore, the present atomic clustering provides more detailed insight into accuracy verification.