Landslide monitoring in southwestern China via time-lapse electrical resistivity tomography

The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated correlation is still poor and inadequate.Thus,in this study,we investigated a typical landslide in southwestern China via time-lapse electrical resistivity tomography（TLERT） in November 2013 and August 2014.We studied landslide mechanisms based on the spatiotemporal characteristics of surface water infiltration and flow within the landslide body.Combined with borehole data,inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock.Preferential flow pathways attributed to fracture zones and fissures were also delineated.In addition,we found that surface water permeates through these pathways into the slipping mass and drains away as fissure water in the fractured bedrock,probably causing the weakly weathered layer to gradually soften and erode,eventually leading to a landslide.Clearly,TLERT dynamic monitoring can provide precursory information of critical sliding and can be used in landslide stability analysis and prediction.

The AVO Effect of Formation Pressure on Time-Lapse Seismic Monitoring in Marine Carbon Dioxide Storage

The phase change of CO_(2) has a significant bearing on the siting, injection, and monitoring of storage. The phase state of CO_(2) is closely related to pressure. In the process of seismic exploration, the information of formation pressure can be response in the seismic data. Therefore, it is possible to monitor the formation pressure using time-lapse seismic method. Apart from formation pressure, the information of porosity and CO_(2) saturation can be reflected in the seismic data. Here, based on the actual situation of the work area, a rockphysical model is proposed to address the feasibility of time-lapse seismic monitoring during CO_(2) storage in the anisotropic formation. The model takes into account the formation pressure, variety minerals composition, fracture, fluid inhomogeneous distribution, and anisotropy caused by horizontal layering of rock layers(or oriented alignment of minerals). From the proposed rockphysical model and the well-logging, cores and geological data at the target layer, the variation of P-wave and S-wave velocity with formation pressure after CO_(2) injection is calculated. And so are the effects of porosity and CO_(2) saturation. Finally, from anisotropic exact reflection coefficient equation, the reflection coefficients under different formation pressures are calculated. It is proved that the reflection coefficient varies with pressure. Compared with CO_(2) saturation, the pressure has a greater effect on the reflection coefficient. Through the convolution model, the seismic record is calculated. The seismic record shows the difference with different formation pressure. At present, in the marine CO_(2) sequestration monitoring domain, there is no study involving the effect of formation pressure changes on seismic records in seafloor anisotropic formation. This study can provide a basis for the inversion of reservoir parameters in anisotropic seafloor CO_(2) reservoirs.

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.

Resistivity tomography based on multichannel electrodes

With the constantly changing engineering construction sector,the detection accuracy of conventional electrical resistivity tomography(ERT)is no longer suffi cient.A multichannel electrode design(MERT)-based ERT is introduced in this paper to address the growing need for resolution.The imaging accuracy of the ERT method is improved through the collection of apparent resistivity data in various directions by measuring the potential diff erence between diff erent channels.Numerical simulation results of the inclined high-resistivity anomaly model reveal that MERT is a precise representation of the shape,inclined direction,and buried depth of the anomaly,with thoroughfare M2N2 producing the most precise forward and inverse results.Based on the analysis results of the model resolution matrix,when the buried depth of power supply points and the gap between potential acquisition points are 30%-90%and 30%-60%of the electrode distance,respectively,the MERT approach yields superior detection outcomes.The detection eff ect of the MERT method on anomalous bodies with diff erent burial depths under the optimal parameters also indicates that the MERT method can obtain richer potential change information with higher resolution in deep areas compared to the ERT method.With the implementation of the MERT approach,the scope of applications for ERT is expanded,the accuracy of ERT detection is increased,and the progress of near-surface fi ne detection is positively infl uenced.

Experimental study on shear properties and resistivity change of soil-rock mixture

The deterioration of shear resistance in rock and soil masses has resulted in numerous severe natural disasters,highlighting the significance of long-term monitoring for disaster prevention and mitigation.This study explores the use of a non-destructive method to quickly and accurately evaluate the shear properties of soil-rock mixture.The shear stress,shear strain,and resistivity of the soil-rock mixture were tested simultaneously using a combination of direct shear and resistivity tests.The test results show that the resistivity of the soil-rock mixture gradually decreases with increasing shear strain.The resistivity of all specimens ranged approximately from 60 to 130Ω.m throughout the shear process.At the end of the shear test,the vertical failure resistivity showed an irregular“W”shape with increasing rock content.It exhibited a significant negative linear functional relationship with the shear strength.With reference to the determination of cohesion and internal friction angle on the shear strength envelope,the horizontal angle of the vertical failure resistivity-normal stress curve is defined as the resistivity angle,and the intercept of the curve is the resistivity at the initial moment of shear.It has been observed that the resistivity angle is negatively and linearly correlated with the internal friction angle.At the same time,there is a linear growth relationship between resistivity at the initial moment of shear and cohesion.It has been demonstrated that an increase in rock content contributes to a general escalation in both the average structure factor and average shape factor.Meanwhile,a decrease in the anisotropy coefficient has also been noted.These alterations are indicative of the extent of microstructural transformations occurring during the deformation process of the soil-rock mixture.The research results verify the feasibility of real-time deformation monitoring and characterization of shear strength parameters using resistivity.

Optimizing data for electrical resistivity tomography in hardened sites through the ratio method

To reduce the shielding effect of hardened layers on electrical resistivity tomography,a ratio method based on the distortion correction principle and the isolation coefficient is proposed.The effects of the resistivity and thickness of hardened concrete layers on the detection of target objects are explored.Both numerical simulations and indoor tank tests indicate that when the ratio method is employed to correct the original collected data,the maximum allowable error for the isolation coefficient should not exceed 1%.Notably,when the ratio of hardened layer thickness to electrode spacing does not exceed 1,correction through this method significantly enhances the recognition capability of target objects.However,when the hardened layer thickness is greater than the electrode spacing by a factor of 2 or more,the ratio method cannot achieve satisfactory results.The case study of flood control engineering detection in the Zhangxi section of the Huangpen River in Dongzhi County demonstrates that the detection effect after correction by the ratio method is comparable to that for the adjacent unhardened pavement,and the influence of the hardened layer is obviously weakened,resulting in more reliable results.

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.

Time-lapse培养与桌面台式培养箱胚胎培养对胚胎发育的影响

目的探讨Time-lapse培养与桌面台式培养箱胚胎培养对胚胎发育的影响。方法选取2021年3月—2023年3月在本院生殖中心行IVF-ET/ICSI-ET治疗的613个周期的胚胎发育数据,随机分配胚胎培养方式。分为对照组与研究组,其中对照组为桌面台式培养箱方式(360个周期),研究组为Time-lapse培养与桌面台式培养箱方式(253个周期),统计两组胚胎发育质量。结果研究组中正常受精数、可移植胚胎数、形成囊胚数、优质胚胎数、高评分囊胚数、受精率、冷冻胚胎率、胚囊形成率、优质胚胎率、高评分囊胚率高于对照组,组间差异有统计学意义(P<0.05)。结论Time-lapse培养与桌面台式培养箱胚胎培养方式优于桌面台式培养箱方式,可为胚胎培养提供适宜的环境、温度、湿度等,有助于胚胎发育,具有较强的实用性和推广性,值得推广应用。

Cellular models of stress resistance may pave ways to fight neurodegenerative diseases

Alzheimer's disease(AD),the most common form of neurodegeneration,is characterized by selective neuronal vulnerability and brain regionselective neuron demise.The entorhinal cortex and hippoc,ampal CA1 projection neurons are at greater risk in AD whereas other regions display resistance to neurodegeneration.Interestingly,the cerebellum,a phylogenetically very old region,is affected only very late in the disease progression.

Understanding the link between type 2 diabetes mellitus and Parkinson's disease:role of brain insulin resistance

Type 2 diabetes mellitus and Parkinson's disease are chronic diseases linked to a growing pandemic that affects older adults and causes significant socio-economic burden.Epidemiological data supporting a close relationship between these two aging-related diseases have resulted in the investigation of shared pathophysiological molecular mechanisms.Impaired insulin signaling in the brain has gained increasing attention during the last decade and has been suggested to contribute to the development of Parkinson's disease through the dysregulation of several pathological processes.The contribution of type 2 diabetes mellitus and insulin resistance in neurodegeneration in Parkinson's disease,with emphasis on brain insulin resistance,is extensively discussed in this article and new therapeutic strategies targeting this pathological link are presented and reviewed.

Transient extreme insulin resistance in a critically ill patient:A case report

BACKGROUND Acute hyperglycemia due to insulin resistance is common in critically ill patients,typically managed with insulin infusion.However,the occurrence of transient extreme insulin resistance(EIR)requiring exceptional high-dose insulin is rare.CASE SUMMARY We present the case of a 68-year-old woman with pneumonia who suffered an out-of-hospital cardiac arrest,subsequently developing transient EIR following a new episode of sepsis.Remarkably,insulin resistance rapidly reversed when the insulin infusion rate peaked at 960 units/hour(a total of 18224 units on that day),and it was promptly titrated down to zero upon achieving the target glucose level.CONCLUSION Exceptional high-dose insulin infusion may be required in critically ill patients with stress-related EIR,which is typically transient.Clinicians should be aware of the phenomenon and cautious to avoid hypoglycemia and fluid overload during the steep titration of high-dose insulin infusion.

Combined BRAF G469A mutation and echinoderm microtubule associated protein like-4-anaplastic lymphoma kinase rearrangement with resistance:A case report and review of literature

BACKGROUND Through deeper understanding of targetable driver mutations in non-small-cell lung cancer(NSCLC)over the past years,some patients with driver mutations have benefited from the targeted molecular therapies.Although the anaplastic lymphoma kinase and BRAF mutations are not frequent subtypes in NSCLC,the availability of several targeted-drugs has been confirmed through a series of clinical trials.But little is clear about the proper strategy in rare BRAF G469A mutation,not to mention co-exhibition of anaplastic lymphoma kinase and BRAF G469A mutations,which is extremely rare in NSCLC.CASE SUMMARY We present a patient to stage IVA lung adenocarcinoma with coexisting echinoderm microtubule associated protein like-4 rearrangement and BRAF G469A mutation.She received several targeted drugs with unintended resistance and suffered from unbearable adverse events.CONCLUSION Due to the rarity of co-mutations,the case not only enriches the limited literature on NSCLC harbouring BRAF G469A and echinoderm microtubule associated protein like-4 mutations,but also suggests the efficacy and safety of specific multiple-drug therapy in such patients.

Selenoprotein P1 as a biomarker of insulin resistance in pediatric obesity:Insights and implications

This editorial discusses the findings of Elbarky et al on the role of selenoprotein P1(SEPP1)in pediatric obesity and insulin resistance.Their study uncovered si-gnificantly lower SEPP1 Levels in children who were obese compared with hea-lthy peers,demonstrating a negative correlation between SEPP1 levels and mea-sures of adiposity and insulin resistance.These findings suggest that SEPP1 is a biomarker useful in the early identification of insulin resistance in pediatric populations.This editorial emphasizes the clinical implications of the study and calls for further research to validate and explore the role of SEPP1 in metabolic health.

Efficacy of antimicrobials in preventing resistance in solid organ transplant recipients:A systematic review of clinical trials

BACKGROUND In the absence of effective antimicrobials,transplant surgery is not viable,and antirejection immunosuppressants cannot be administered,as resistant infections compromise the life-saving goal of organ transplantation.AIM To evaluate the efficacy of antimicrobials in preventing resistance in solid organ transplant recipients.METHODS A systematic review was conducted using a search methodology consistent with the preferred reporting items for systematic reviews and meta-analyses.This review included randomized clinical trials that evaluated the efficacy of antimicrobial agents(prophylactic or therapeutic)aimed at preventing antimicrobial resistance.The search strategy involved analyzing multiple databases,including PubMed/MEDLINE,Web of Science,Embase,Scopus,and SciELO,as well as examining gray literature sources on Google Scholar.A comprehensive electronic database search was conducted from the databases’inception until May 2024,with no language restrictions.RESULTS After the final phase of the eligibility assessment,this systematic review ultimate-ly included 7 articles.A total of 2318 patients were studied.The most studied microorganisms were cytomegalovirus,although vancomycinresistant enterococci,Clostridioides difficile,and multidrug-resistant Enterobacterales were also analyzed.The antimicrobials used in the interventions were mainly maribavir,valganciclovir,gancic-lovir,and colistin-neomycin.Of concern,all clinical trials showed significant proportions of resistant microorga-nisms after the interventions,with no statistically significant differences between the groups(mean resistance 13.47%vs 14.39%),except for two studies that demonstrated greater efficacy of maribavir and valganciclovir(mean resistance 22.2%vs 41.1%in the control group;P<0.05).The total reported deaths in three clinical trials were 75,and there were 24 graft rejections in two studies.CONCLUSION All clinical trials reported significant proportions of antimicrobial-resistant microorganisms following interventions.More high-quality randomized clinical trials are needed to corroborate these results.

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.

Response simulation and theoretical calibration of a dual- induction resistivity LWD tool

In this paper, responses of a new dual-induction resistivity logging-while-drilling （LWD） tool in 3D inhomogeneous formation models are simulated by the vectorfinite element method （VFEM）, the influences of the borehole, invaded zone, surroundingstrata, and tool eccentricity are analyzed, and calibration loop parameters and calibrationcoefficients of the LWD tool are discussed. The results show that the tool has a greater depthof investigation than that of the existing electromagnetic propagation LWD tools and is moresensitive to azimuthal conductivity. Both deep and medium induction responses have linearrelationships with the formation conductivity, considering optimal calibration loop parametersand calibration coefficients. Due to the different depths of investigation and resolution, deepinduction and medium induction are affected differently by the formation model parameters,thereby having different correction factors. The simulation results can provide theoreticalreferences for the research and interpretation of the dual-induction resistivity LWD tools.

使用time-lapse筛选早期IVF/ICSI胚胎及其临床结局

目的通过比较使用time-lapse（延迟摄像）和传统形态学方法筛选IVF/ICSI胚胎的临床结局,评价time-lapse用于早期胚胎观察和筛选的价值。方法回顾性分析139个IVF/ICSI周期的资料,根据胚胎的筛选方法,分为time-lapse monitoring组（TLM组）（n=68）和对照组（n=71）,比较两组间的βHCG阳性率、临床妊娠率和胚胎着床率,并根据女方年龄、受精方式进行亚组分析。结果 TLM组的βHCG阳性率、临床妊娠率、胚胎着床率分别为：66.2%、61.8%、47.1%;对照组的βHCG阳性率、临床妊娠率、胚胎着床率分别为：47.9%、43.7%、30.3%;TLM组的βHCG阳性率、临床妊娠率、胚胎着床率均高于对照组,且差异均有统计学意义（P〈0.05）。亚组分析显示：相较于年龄≤30岁的患者,年龄31~35岁的患者利用time-lapse更能明显改善临床结局;利用time-lapse能明显提高IVF周期的βHCG阳性率、临床妊娠率、胚胎着床率,但对于ICSI和TESA周期,效果则不理想。结论使用time-lapse动态监测胚胎并根据胚胎的形态动力学参数对胚胎进行评价和筛选,与传统方法相比,能获得更好的临床结局;年龄较大的（〉30岁）或者是进行IVF周期的患者更能从中获益。

利用Time-lapse技术筛选早期胚胎对IVF-ET妊娠结局的影响

目的探索利用Time-lapse系统筛选早期胚胎的临床应用价值。方法回顾性分析本中心2016年7月至2017年12月,第一次新鲜或复苏周期D3卵裂期胚胎移植的患者资料,根据胚胎评估方法分为Time-lapse系统组(TLM组,n=74)和传统形态学评分组(CMA组,n=951),比较这两种不同胚胎筛选方法对临床结局的影响。结果患者的不孕年限、体重指数、基础FSH、基础LH、E2、AMH、窦卵泡数、内膜厚度和周期类型等一般情况,在TLM组和CMA组均无显著差异(P均>0.05);TLM组年龄显著高于CMA组[(31.8±4.2)vs.(30.8±4.4),P<0.05],而平均移植胚胎数显著少于CMA组[(1.7±0.5)vs.(1.9±0.3),P<0.05];患者的临床结局,包括临床妊娠率、种植率、流产率、宫外孕率、双胎率和移植两个胚胎的双胎率等在两组间均无显著差异(P均>0.05)。进一步按照年龄分层分析,在<35岁患者,患者的一般情况在两组间均无显著差异(P均>0.05),TML组的平均移植胚胎数显著少于CMA组[(1.7±0.5)vs.(1.9±0.3),P<0.05],而患者临床结局在两组间亦无显著差异(P>0.05);在≥35岁患者,TML组的平均移植胚胎数显著少于CMA组[(1.7±0.5)vs.(1.9±0.4),P<0.05],而患者的一般情况和临床结局在两组间亦无显著差异(P>0.05)。结论利用Time-lapse技术选择早期胚胎,可以在显著减少移植胚胎数的基础上,维持稳定的临床妊娠结局。因此,认为Time-lapse技术可以在一定程度上优选出更具发育潜能的胚胎,为早期胚胎单胚胎移植提供新方法。

Analysis and application of the response characteristics of DLL and LWD resistivity in horizontal well

There exist different response characteristics in the resistivity measurements of dual laterolog （DLL） and logging while drilling （LWD） electromagnetic wave propagation logging in highly deviated and horizontal wells due to the difference in their measuring principles. In this study, we first use the integral equation method simulated the response characteristics of LWD resistivity and use the three dimensional finite element method （3D-FEM） simulated the response characteristics of DLL resistivity in horizontal wells, and then analyzed the response differences between the DLL and LWD resistivity. The comparative analysis indicated that the response differences may be caused by different factors such as differences in the angle of instrument inclination, anisotropy, formation interface, and mud intrusion. In the interface, the curves of the LWD resistivity become sharp with increases in the deviation while those of the DLL resistivity gradually become smooth. Both curves are affected by the anisotropy although the effect on DLL resistivity is lower than the LWD resistivity. These differences aid in providing a reasonable explanation in the horizontal well. However, this can also simultaneously lead to false results. At the end of the study, we explain the effects of the differences in the interpretation of the horizontal well based on the results and actual data analysis.