Application of 2-D and 3-D Geo-electrical Resistivity Tomography and Geotechnical Soil Evaluation for Engineering Site Investigation:A Case Study of Okerenkoko Primary School,Warri-Southwest,Delta State,Nigeria

In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects.

A novel method for determining the resistivity of compressed superconducting materials

The measurement of resistivity in a compressed material within a diamond anvil cell presents significant challenges.The high-pressure exper-imental setup makes it difficult to directly measure the size changes induced by pressure in the three crystallographic directions of the sample.In this study,we introduce a novel and effective method that addresses these technical challenges.This method is anticipated to offer a valuable foundation for high-pressure investigations on quantum materials,particularly those with anisotropic layered structures.

Characterization of Aquifers in Crystalline and Crystallophyll Basement Zones Using the Electrical Resistivity Method (Trails and Electrical Soundings) in the Gagnoa Region, (Central-Western Côte d’Ivoire)

Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambrian basement contains most of the region’s water resources. This is at the origin of the high failure rate during the various hydrogeological prospecting campaigns. Methodology: The database consists of resistivities from 42 holes and 51 trails drilled as part of the implementation of high-throughput drilling in the study area. The objective of this study is to deepen the knowledge of the fissured basement by interpreting profile curves and electrical soundings. It will be a question of classifying the different types of anomalies obtained on the profiles and their shapes. The orientation of the lineaments observed on the profiles was determined. Results: The interpretation of the geophysical data revealed various anomalies, the main ones being of the CC (Conductor Compartment) and CEDP (Contact between two bearings) types. These types of anomalies are mainly expressed in various forms: the “V”, “W” and “U” shapes. From these anomalies and the appearance of the electrical profiles, lineaments and their orientations were identified with N90-100, N130-140, N170-180 as major orientations. Conclusion: These results could contribute to a better understanding of the fractured environment of the Gagnoa region.

Study on theoretical model for electrical explosion resistivity of Al/Ni reactive multilayer foil

Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones.

Research on geo-electrical resistivity observation system specially used for earthquake monitoring in China

This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.

Application of the Electrical Resistivity Method in Precision Agriculture of Coffee Cultivation, in the Kabiri Area, Ícolo e Bengo Township, Luanda, Angola

The electrical resistivity method is a geophysical tool used to characterize the subsoil and can provide an important information for precision agriculture. The lack of knowledge about agronomic properties of the soil tends to affect the agricultural coffee production system. Therefore, research related to geoelectrical properties of soil such as resistivity for characterization the region of the study for coffee cultivation purposes can improve and optimize the production. This resistivity method allows to investigate the subsurface through different techniques: 1D vertical electrical sounding and electrical imaging. The acquisition of data using these techniques permitted the creation of 2D resistivity cross section from the study area. The geoelectrical data was acquired by using a resistivity meter equipment and was processed in different softwares. The results of the geoelectrical characterization from 1D resistivity model and 2D resistivity electrical sections show that in the study area of Kabiri, there are 8 varieties of geoelectrical layers with different resistivity or conductivity. Near survey in the study area, the lowest resistivity is around 0.322 Ω·m, while the highest is about 92.1 Ω·m. These values illustrated where is possible to plant coffee for suggestion of specific fertilization plan for some area to improve the cultivation.

The near-room-temperature upsurge of electrical resistivity in Lu-H-N is not superconductivity,but a metal-to-poor-conductor transition

The recent report of superconductivity in nitrogen-doped lutetium hydride(Lu-H-N)at 294 K and 1 GPa brought hope for long-sought-after ambient-condition superconductors.However,the failure of scientists worldwide to independently reproduce these results has cast intense skepticism on this exciting claim.In this work,using a reliable experimental protocol,we synthesized Lu-H-N while minimizing extrinsic influences and reproduced the sudden change in resistance near room temperature.With quantitative comparison of the temperaturedependent resistance between Lu-H-N and the pure lutetium before reaction,we were able to clarify that the drastic resistance change is most likely caused by a metal-to-poor-conductor transition rather than by superconductivity.Herein,we also briefly discuss other issues recently raised in relation to the Lu-H-N system.

The influence of resistance exercise training prescription variables on skeletal muscle mass,strength,and physical function in healthy adults:An umbrella review

Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.Methods:Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass(or its proxies),strength,and/or physical function in healthy adults aged>18 years.Results:We identified 44 systematic reviews that met our inclusion criteria.The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews;standardized effectiveness statements were generated.We found that RT was consistently a potent stimulus for increasing skeletal muscle mass(4/4 reviews provide some or sufficient evidence),strength(4/6 reviews provided some or sufficient evidence),and physical function(1/1 review provided some evidence).RT load(6/8 reviews provided some or sufficient evidence),weekly frequency(2/4 reviews provided some or sufficient evidence),volume(3/7 reviews provided some or sufficient evidence),and exercise order(1/1 review provided some evidence)impacted RT-induced increases in muscular strength.We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass,while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass.There was insufficient evidence to conclude that time of day,periodization,inter-set rest,set configuration,set end point,contraction velocity/time under tension,or exercise order(only pertaining to hypertrophy)influenced skeletal muscle adaptations.A paucity of data limited insights into the impact of RT prescription variables on physical function.Conclusion:Overall,RT increased muscle mass,strength,and physical function compared to no exercise.RT intensity(load)and weekly frequency impacted RT-induced increases in muscular strength but not muscle hypertrophy.RT volume(number of sets)influenced muscular strength and hypertrophy.

Reversal of tamoxifen resistance by artemisinin in ER+breast cancer:bioinformatics analysis and experimental validation

Breast cancer is the leading cause of cancer-related deaths in women worldwide,with Hormone Receptor(HR)+being the predominant subtype.Tamoxifen(TAM)serves as the primary treatment for HR+breast cancer.However,drug resistance often leads to recurrence,underscoring the need to develop new therapies to enhance patient quality of life and reduce recurrence rates.Artemisinin(ART)has demonstrated efficacy in inhibiting the growth of drug-resistant cells,positioning art as a viable option for counteracting endocrine resistance.This study explored the interaction between artemisinin and tamoxifen through a combined approach of bioinformatics analysis and experimental validation.Five characterized genes(ar,cdkn1a,erbb2,esr1,hsp90aa1)and seven drug-disease crossover genes(cyp2e1,rorc,mapk10,glp1r,egfr,pgr,mgll)were identified using WGCNA crossover analysis.Subsequent functional enrichment analyses were conducted.Our findings confirm a significant correlation between key cluster gene expression and immune cell infiltration in tamoxifen-resistant and-sensitized patients.scRNA-seq analysis revealed high expression of key cluster genes in epithelial cells,suggesting artemisinin’s specific impact on tumor cells in estrogen receptor(ER)-positive BC tissues.Molecular target docking and in vitro experiments with artemisinin on LCC9 cells demonstrated a reversal effect in reducing migratory and drug resistance of drug-resistant cells by modulating relevant drug resistance genes.These results indicate that artemisinin could potentially reverse tamoxifen resistance in ER-positive breast cancer.

Biomass-enhanced Janus sponge-like hydrogel with salt resistance and highstrength for efficient solar desalination

Interfacial solar-driven evaporation technology shows great potential in the field of industrial seawater desalination, and the development ofefficient and low-cost evaporation materials is key to achieving large-scale applications. Hydrogels are considered to be promising candidates;however, conventional hydrogel-based interfacial solar evaporators have difficulty in simultaneously meeting multiple requirements, including ahigh evaporation rate, salt resistance, and good mechanical properties. In this study, a Janus sponge-like hydrogel solar evaporator (CPAS) withexcellent comprehensive performance was successfully constructed. The introduction of biomass agar (AG) into the polyvinyl alcohol (PVA)hydrogel backbone reduced the enthalpy of water evaporation, optimized the pore structure, and improved the mechanical properties. Meanwhile, by introducing hydrophobic fumed nano-silica aerogel (SA) and a synergistic foaming-crosslinking process, the hydrogel spontaneouslyformed a Janus structure with a hydrophobic surface and hydrophilic bottom properties. Based on the reduction of the evaporation enthalpy andthe modulation of the pore structure, the CPAS evaporation rate reached 3.56 kg m^(-2) h^(-1) under one sun illumination. Most importantly, owingto the hydrophobic top surface and 3D-interconnected porous channels, the evaporator could work stably in high concentrations of salt-water(25 wt% NaCl), showing strong salt resistance. Efficient water evaporation, excellent salt resistance, scalable preparation processes, and low-costraw materials make CPAS extremely promising for practical applications.

Drug resistance mechanisms in cancers:Execution of prosurvival strategies

One of the quintessential challenges in cancer treatment is drug resistance.Several mechanisms of drug resistance have been described to date,and new modes of drug resistance continue to be discovered.The phenomenon of cancer drug resistance is now widespread,with approximately 90% of cancer-related deaths associated with drug resistance.Despite significant advances in the drug discovery process,the emergence of innate and acquired mechanisms of drug resistance has impeded the progress in cancer therapy.Therefore,understanding the mechanisms of drug resistance and the various pathways involved is integral to treatment modalities.In the present review,I discuss the different mechanisms of drug resistance in cancer cells,including DNA damage repair,epithelial to mesenchymal transition,inhibition of cell death,alteration of drug targets,inactivation of drugs,deregulation of cellular energetics,immune evasion,tumor-promoting inflammation,genome instability,and other contributing epigenetic factors.Furthermore,I highlight available treatment options and conclude with future directions.

Identification of Fusarium wilt resistance gene SiRLK1 in Sesamum indicum L.

Sesame Fusarium wilt(SFW),caused by Fusarium oxysporum f.sp.sesami(Fos),is one of the most devastating diseases affecting sesame cultivation.Deciphering the genetic control of SFW resistance is pivotal for effective disease management in sesame.An inheritance study on a cross between the highly resistant variety Yuzhi 11 and the highly susceptible accession Sp1 using a Fos pathogenicity group 1 isolate indicated that resistance was conferred by a single dominant allele.The target locus was located in a 1.24 Mb interval on chromosome 3 using a combination of cross-population association mapping and bulked segregant analysis.Fine genetic mapping further narrowed the interval between 21,350 and 21,401 kb.The locus Sindi_0812400 was identified as the SFW resistance gene and officially designated SiRLK1.This gene encodes a specific malectin/receptor-like protein kinase with three putative tandem kinase domains and is considered a kinase fusion protein.Sequence analysis revealed that a high proportion(49.44%)of variants within the locus was located within the kinase domainⅢ,and several of which were evidently associated with the diversity in SFW response,indicating the critical role of kinase domainⅢin expression of disease resistance.These findings provide valuable information for further functional analysis of SFW resistance genes and marker-assisted resistance breeding in sesame.

Electrical resistivity change of saturated sand during reliquefaction under hammering loading

The electrical resistivity method was verified as an optional technique to monitor the change of mesostructure of saturated soils.To investigate the change laws of resistivity and analyze the reliquefaction meso-mechanism during the consecutive liquefaction process,five successive impact liquefaction tests were performed in a one-dimensional cubical chamber.The resistivity variation and excess pore water pressure(EPWP)were measured.The results indicate that the excess pore water pressure experienced four stages:quick increase stage,slow dissipation stage,rapid dissipation stage,and stability stage.Meanwhile,a swift decrease of resistivity emerged before the start of the rapid dissipation stage of EPWP,and then an increasing trend of resistivity is demonstrated with the densification of soil.It is proved that the vertical pore connectivity of liquefied sand is better than its random deposit state,based on a comparative study of porosity calculated from the settlement and resistivity of sand after each test.

CircTHSD4 promotes the malignancy and docetaxel (DTX) resistance in prostate cancer by regulating miR-203/HMGA2 axis

Objective:Circular ribose nudeic acids(circRNAs)are implicated in tumor progression and drug resistance of prostate cancer(PCa).The current work explored the function of circ_0005203(aircTHSD4)in the malignancy and docetaxel(DTX)resistance of PCa.Methods:circTHSD4 expression within PCa as well as matched non-carcinoma samples was measured through real time reverse transcription quantitative polymerase chain reaction(RT-qPCR).In addition,a subcellular fraction assay was conducted to determine circTHSD4 subcellular localization within PCa cells.In addition,we performed a Western blot(WB)assay to detect high mobility.group A2 protein(HMGA2)levels.Besides,functional associations of two molecules were investigated through dual luciferase reporter assay.Cell Counting Kit(CCK)-8,colony formation together with Transwell assay was conducted to assess malignant phenotypes of PCa cells,whereas flow cytometry was performed to determine cell apoptosis.Furthermore,a xenograft mouse model was constructed to verify the effect of circTHSD4 on the carcinogenesis of PCa cells.Results:According to RT-qPCR results,circTHSD4 was up-regulated within PCa tissues and cells,which predicted the dismal prognostic outcome of PCa cases.circTHSD4 silencing within PCa cells markedly suppressed cell growth,migration,and colony fomation.circTHSD4 silencing remarkably elevated PCa cell apoptosis and carcinogenesis within the xenograft model.Further,circTHSD4 silencing enhanced docetaxel(DTX)sensitivity in PCa cells.Furthermore,we demonstrated that circTHSD4 modulated the malignancy of PCa cells by regulating HMGA2 expression through sponging miR 203.Conclusion:Together,our findings suggest that cirCTHSD4 overexpression could promote the malignant phenotype and DTX resistance in PCa through the regulation of the miR 203/HMGA2 axis.

Evaluation of Factors of Soil Resistivity in the Niger Delta

Soil conductivity is responsible for its aggressive behavior to metallic objects either in contact or buried in the ground. Rapid deterioration and eventual rupture of pipelines leading ultimately to crude oil spillages have been of economic as well as environmental concern. Although many factors contribute to soil resistivity, these relationships have hardly been quantitatively expressed. This paper explores the factors affecting soil resistivity firstly by matching the spatial regional distribution with each of the identified factors of influence, including ground elevation soil type, depth to water table and undrained strength. 183 Vertical Electrical Sounding VES with the ABEM SAS 1000, using Schlumberger electrode configuration were carried out along a pipeline route to generate resistivity distribution across a linear alignment that traverses three geomorphic sub-environments in the Niger Delta Region. The apparent resistivity values averaged over depths of 3 m and 10 m were plotted against the co-ordinates using Surfer-16 and overlaid on Google earth Pro to produce a spatial distribution with enhanced location visibility. The results show that apparent resistivity is influenced by depth to water table with lower values in areas of shallow water table occurrence. Furthermore, it is shown that changes in resistivity below the water table are more due to variation in soil type. Within a soil type above the water table, soil resistivity increases monotonically with depth until the depth of probe extends to a different soil horizon. Results of this study provide guidance as to what ground resistivity to expect in different part of the delta as well as provide valuable information to assess the risks to assets either as a means of prioritizing maintenance or of improving design for new installations in the Niger Delta Region.

Insulin resistance as the molecular link between diabetes and Alzheimer's disease

Diabetes mellitus(DM)and Alzheimer's disease(AD)are two major health concerns that have seen a rising prevalence worldwide.Recent studies have indicated a possible link between DM and an increased risk of developing AD.Insulin,while primarily known for its role in regulating blood sugar,also plays a vital role in protecting brain functions.Insulin resistance(IR),especially prevalent in type 2 diabetes,is believed to play a significant role in AD's development.When insulin signalling becomes dysfunctional,it can negatively affect various brain functions,making individuals more susceptible to AD's defining features,such as the buildup of beta-amyloid plaques and tau protein tangles.Emerging research suggests that addressing insulin-related issues might help reduce or even reverse the brain changes linked to AD.This review aims to explore the relationship between DM and AD,with a focus on the role of IR.It also explores the molecular mechanisms by which IR might lead to brain changes and assesses current treatments that target IR.Understanding IR's role in the connection between DM and AD offers new possibilities for treatments and highlights the importance of continued research in this interdisciplinary field.

Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

Novel insights into D-Pinitol based therapies:a link between tau hyperphosphorylation and insulin resistance

Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau protein.Among the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug development.The present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.

Exploring an eco-friendly approach to improve soil tensile behavior and cracking resistance

Soil tensile strength is a critical parameter governing the initiation and propagation of tensile cracking.This study proposes an eco-friendly approach to improve the tensile behavior and crack resistance of clayey soils.To validate the feasibility and efficacy of the proposed approach,direct tensile tests were employed to determine the tensile strength of the compacted soil with different W-OH treatment concentrations and water contents.Desiccation tests were also performed to evaluate the effectiveness of W-OH treatment in enhancing soil tensile cracking resistance.During this period,the effects of W-OH treatment concentration and water content on tensile properties,soil suction and microstructure were investigated.The tensile tests reveal that W-OH treatment has a significant impact on the tensile strength and failure mode of the soil,which not only effectively enhances the tensile strength and failure displacement,but also changes the brittle failure behavior into a more ductile quasi-brittle failure behavior.The suction measurements and mercury intrusion porosimetry(MIP)tests show that W-OH treatment can slightly reduce soil suction by affecting skeleton structure and increasing macropores.Combined with the microstructural analysis,it becomes evident that the significant improvement in soil tensile behavior through W-OH treatment is mainly attributed to the W-OH gel's ability to provide additional binding force for bridging and encapsulating the soil particles.Moreover,desiccation tests demonstrate that W-OH treatment can significantly reduce or even inhibit the formation of soil tensile cracking.With the increase of W-OH treatment concentration,the surface crack ratio and total crack length are significantly reduced.This study enhances a fundamental understanding of eco-polymer impacts on soil mechanical properties and provides valuable insight into their potential application for improving soil crack resistance.

Fabrication and characterization of NiCr-based films with high resistivity and low temperature coefficient of resistance

As a metal alloy,NiCr films have a relatively high resistivity and low temperature coefficient of resistance (TCR) and are widely used in electronic components and sensors.However,the resistivity of pure NiCr is insufficient for high-resistance and highly stable film resistors.In this study,a quaternary NiCrAlSi target (47:33:10:10,wt.%) was successfully used to prepare resistor films with resistivities ranging from 1000 to 10 000μΩcm and TCR within±100 ppm/K.An oxygen flow was introduced during the sputtering process.The films exhibit hightemperature stability at 450℃.The films were analyzed using Auger electron spectroscopy,x-ray diffraction,time-of-flight secondary-ion mass spectrometry,and x-ray photoelectron spectroscopy.The results show that the difference in the oxide proportion of the films caused the differences in resistivity.The near-zero TCR values were considered to be due to the competition between silicon and other metals.This study provides new insights into the electrical properties of NiCr-based films containing Si,which will drive the manufacturing of resistors with high resistivity and zero TCR.