bluuebunny/crossref_metadata_2025 huggingface dataset:
New Insights on Scale-dependent Surface-Groundwater Exchange from a Floating Self-potential Dipole
Authors: Ikard Scott J. , Teeple Andrew P. , Payne Jason D. , Stanton Gregory P. , Banta J. Ryan
Published: December 2020

In south-central Texas the lower Guadalupe River has incised into the outcrop of the Carrizo-Wilcox aquifer. The river and the aquifer are hydraulically connected across the outcrop, although the connectivity is obscured at the surface by alluvium and surface-water and groundwater exchange dynamics are currently poorly understood. To investigate surface-water and groundwater exchange dynamics between the lower Guadalupe River and the Carrizo-Wilcox aquifer, a geophysical study was completed along a 14.86 km reach of the river by using water-borne gradient self-potential (SP) profiling and two-dimensional direct-current electric resistivity tomography. This paper explores the applicability of these water-borne geoelectric methods in delineating gaining and losing channel reaches, and demonstrates that geoelectric signals in the form of total electric field strength can be logged with an electric dipole and decomposed into component SP signals depicting regional and local groundwater flow patterns attributable to regional and localized hydraulic gradients. Localized SP anomalies of several tens of millivolts, indicative of hyporheic exchange flows, are observed and superimposed upon a 124 mV regional SP anomaly indicative of ambient groundwater exchange flows between the river and the aquifer. The observed SP signals are interpreted through two-dimensional finite-element modeling of streaming potentials attributable to ambient groundwater exchange and hyporheic exchange flow patterns. Variables of the channel environment such as temperature and concentration gradients, depth, and velocity are considered and subsequently eliminated as alternative sources of the SP signals that are presented.
Inverse Methods to Improve Accuracy of Water Content Estimates from Multi-offset GPR
Authors: Parsekian Andrew D.
Published: December 2020

Ground penetrating radar (GPR) is a powerful hydrogeophysical tool for estimating porosity and water content of geologic materials using radar wave velocities and appropriate petrophysical relations. In substrates with more than one layer of interest, surface-based multi-offset measurements require careful analysis to accurately retrieve physical properties for each layer. Frequently, Dix inversion is used to calculate interval velocities, however the assumptions and limitations of this approach are widely known. In particular for survey geometries and targets encountered with GPR, the assumptions inherent to Dix inversion are readily violated, and therefore inverse modeling is required to avoid velocity error. While the impact on velocity incurred by violating the assumptions of Dix inversion is well understood, the effects on water content estimates have not been widely reported and are therefore the subject of this work. In a subsurface representative of an unsaturated zone overlying an aquifer, error in excess of 50% in water content due to violating the assumptions of Dix inversion is demonstrated. Examples are shown using raytracing inversion to solve for subsurface water content structure that avoids the errors inherent to Dix inversion. These results are intended to underscore the importance of minimizing assumptions and using more correct physics when analyzing multi-offset GPR data, particularly due to the large potential errors that may be encountered if water content estimation is the main objective.
The Application of Resistivity and Induced Polarization Methods in Identification of Skarn Alteration Haloes: A Case Study in the Qale-Alimoradkhan Area
Authors: Mashhadi Seyyed Reza , Ramazi Hamidreza
Published: December 2020

This paper investigates the capability of the resistivity and induced polarization (IP) methods to delineate skarn alteration haloes within the Qale-Alimoradkhan skarn copper deposit. This deposit is located in the Sanandaj-Sirjan geological and structural zone, Hamedan province, Iran. It is understood that fresh limestone and metamorphosed limy units including skarns represent high resistivity anomalies whereas granodiorite intrusions represent medium to low resistivity responses. Four profiles were selected to explore the sulfide-rich zones within the deposit using the Combined Resistivity Sounding and Profiling (CRSP) array. After the appropriate selection of inversion parameters, the inverted models were in good agreement with the known geological features. The resistivity response of the intrusive rocks were found to be alteration dependent. Furthermore, IP targets likely represent sulfide-rich zones. Our study suggests that if preexisting knowledge regarding the geological setting is available, then resistivity and IP can be helpful in the exploration of skarn mineralization.
GPR Measurements for Spatial Investigations at the Asse Salt Structure
Authors: Gundelach Volker
Published: December 2020

The potash mine in the Asse salt structure, now used as repository for nuclear waste, is in some parts going to be refilled for mechanical stability reasons. As a part of that work, old blind shafts were prepared and offer the option for ground penetrating radar (GPR) measurements on vertical profiles in the mine. Horizontal profiles can be carried out in accessible drifts at the margin of the mine. The salt structure has mainly been explored from the surface by seismic measurements and boreholes. Due to the accuracy of these investigations and the openings and drifts inside the mine, the geological composition of the salt structure is known. East of the mine, the geological model is based on little information. Therefore, boreholes were drilled in that region and direction sensitive borehole tools provide additional structural knowledge. Vertical, horizontal and radial profiles in the mine have allowed imaging the complex geological structural information by mapping distance and direction of reflecting objects. With these results, a three dimensional geological model of the salt structures can now be optimized. This project is conceived and controlled by the operator of the mine the German Federal company BGE (Bundesgesellschaft für Endlagerung). BGR is commissioned amongst others for GPR measurements.
Influence of Concrete Carbonation on Electromagnetic Permittivity Measured by GPR and Capacitive Techniques
Authors: Dérobert Xavier , Villain Géraldine , Balayssac Jean-Paul
Published: December 2020

This paper addresses the effect of concrete carbonation on the propagation and dispersion of electromagnetic (EM) waves and the capability of two EM, non-destructive techniques to detect this pathology. A capacitive technique operating at low frequency (around 33 MHz) and a ground penetrating radar (GPR) with a 1.5 GHz antenna were tested for the monitoring of reinforced concrete structures. To better understand the phenomena involved in concrete carbonation, the results of two complementary experimental campaigns were analyzed for saturated concretes. First, the dispersion curves of complex permittivity were measured for both carbonated and non-carbonated samples by a cylindrical coaxial EM cell. Due to carbonation, the permittivity decreased and the level of dispersion reduced slightly. Second, using GPR (coupled at approximately 900 MHz) and capacitive measurements conducted on controlled slabs, it was confirmed that the real part of the relative permittivity decreased within a range of 2 at 33 MHz and a range of 1 to 900 MHz, while the radar signal amplitude increased.
Case Histories of GPR for Animal Burrows Mapping and Geometry
Authors: Sherrod Laura , Sauck William , Simpson Edward , Werkema Dale , Swiontek Jarred
Published: December 2020

Ground-penetrating radar (GPR) has a wide range of applications, from geologic mapping to concrete inspection. A recently emerging GPR application is deployment in biological investigations as a non-invasive technique. Geophysical mapping of features such as tree roots and turtle burrows has proved valuable for the understanding of these subsurface systems for ecological, environmental, or engineering purposes. Four case histories of GPR investigations pertaining to animal burrows are described: cutter ants in Brazil, groundhogs in Michigan, and groundhogs, and burrowing bees in Pennsylvania. Cutter ants ( Atta spp.) in Amazonian Brazil are known to construct burrows of nearly the same dimensions as groundhogs as they excavate galleries up to 7 m deep for leaf storage. Cutter ant burrows are hazardous to heavy equipment and may also cause loss of mud circulation during rotary drilling. Groundhogs ( Marmota monax), found throughout the United States, cause unseen hazards, particularly for equestrian facilities where a sudden collapse can cause severe injuries to both horse and rider. Burrowing bees ( Colletes inaequalis) are common in the northeastern United States. The size of the bee burrows is significantly smaller than that of the cutter ants and the groundhogs. The data for these surveys were collected over a twenty-year span, crossing several generations of survey equipment and processing techniques. Together, these four case histories highlight the historic and current capabilities of GPR systems applied to mapping subsurface burrow systems. These examples demonstrate the important impact near surface heterogeneities have in altering ecological, environmental, or engineering systems and the utility of GPR for mapping such heterogeneities.
Topographic Correction for the Data of SQUID-based TEM Using a Ground Loop
Authors: Ji Yanju , Zhao Yi , Du Shangyu , Li Dongsheng , Zhang Yi , Rong Liangliang , Zhao Jing
Published: December 2020

Superconducting quantum interference device (SQUID) can be used to detect the signal of transient electromagnetic method (TEM) due to its superiority of high sensitivity in the low frequency range. However, the measuring direction of SQUID is hardly consistent with the normal direction of the transmitting coil of a TEM system because of the undulating topography in the field. In this case, the central magnetic field measured by SQUID is only a component of the theoretical central magnetic field. There will be larger errors if we directly use the measured central magnetic field for geological interpretation. To solve this problem, we propose a topographic correction method for the data of SQUID-based TEM using ground loop. The theoretical central magnetic field of the ground loop is calculated after the trapezoidal transmitting current wave is turned off. Then, we use the theoretical central magnetic field of the ground loop as the reference to correct the measured central magnetic field of SQUID-based on the trigonometric function relation between the measuring direction of SQUID and the topographic inclination. The experiment of SQUID-based TEM using a ground loop was carried out in the field. The result shows that at the measurement point with larger topographic inclination, the average absolute error of the measured central magnetic field reduces significantly with the proposed correction method. This method can also be applied to the correction of complex topographic effects when using SQUID to measure three components of magnetic field.
Calibration of a Piezoelectric Transducer through Laser Measurements and Numerical Simulation
Authors: Mahbaz SeyedBijan , Cascante Giovanni , Dusseault Maurice B.
Published: December 2020

A piezoelectric transducer is an electromechanical sensor which converts electrical energy (voltage signal) to mechanical energy (displacement signal) and vice versa by taking advantage of the piezoelectric crystal. Depending on the physical combination of transducer parts, sensors may have a linear or non-linear response to the input signal. In seismic tests such as ultrasonic non-destructive testing (NDT) methods, analyzing stress wave propagation through the specimen gives an assessment of its condition. The signal attenuation is an important parameter to assess the condition of specimen which can be done by having the displacement signal as an output. However, instead of the displacement signal, the piezoelectric transducer provides the voltage signal as an output. Therefore, to get reliable and accurate results, it is essential to calibrate the transducers. An appropriate calibration results in a suitable Transfer Function (TF) which can be used to properly calculate the displacement signal. In this study, the output displacement of a 1 MHz piezoelectric transducer is measured using a laser vibrometer with a nanometer resolution. Measurements and calculated TF showed at frequencies of 0.1, 1, and 1.5 MHz, TF values are 0.8, 0.08, and 0.2 respectively which is a non-linear relation between displacement (absolute signal) and voltage (relative signal) as it was expected. Then, numerical simulation is implemented as part of this study to simulate all electrical and mechanical components of the piezoelectric transducer. The simulation was verified with the absolute displacement measurements result from the laser vibrometer.
Induced Polarization and Resistivity of Second Potential Differences (SPD) with Focused Sources Applied to Environmental Problems
Authors: López-González Aide E. , Tejero-Andrade Andrés , Hernández-Martínez Jejanny L. , Prado Blanca , Chávez René E.
Published: December 2020

A novel technique is proposed to improve shallow induced polarization (IP) and resistivity survey results. We propose the apparent resistivity and apparent chargeability of second potential differences (SPD), employing two focused sources (FS) mathematically manipulated by superposition. To test the idea, a synthetic model is developed with two bodies. The first body is a small shallow heterogeneity which is above the second and larger body. This synthetic model illustrates the shape and response of the apparent resistivity and chargeability for FS under the random noise and masking effect. These processes reduce electromagnetic coupling, telluric noise, contamination in channel links, and small heterogeneous responses.

A field test of the SPD for FS was carried out in an agricultural site irrigated with wastewater, where contaminated water laden with metals has been accumulating for years in the soil. Soil samples were collected and analyzed throughout the geophysical survey to correlate the resistivity-IP results. Soil laboratory analysis included metal content, moisture content and texture. The parameters computed after applying the SPD for FS depicted a better lateral resolution where vertical and horizontal boundaries of the anomaly zones were well defined. It was possible to determine the low permeability horizontal layer made of clay-soil (called tepetate), which is a barrier for water and metals.
Assessing Relations Between Electrical and Geotechnical Properties of Sand-Clay Mixtures Using Jonscher Fractal Power Law Model
Authors: Boadu Fred Kofi , Ampadu Samuel
Published: December 2020

The geotechnical properties of unconsolidated geo-materials such as soils are influenced by modifications of their micro-structure, texture, mineralogy, water content and imposed effective stress levels. Fundamental relations between the characteristic electrical parameters describing the electrical responses soils based on a fractal power law model with scaling properties, and parameters influencing their geotechnical behavior are investigated. Low frequency electrical conductivity laboratory measurements were performed on sand and clay mixtures subjected to varying effective stress levels with concurrent measurements of their geotechnical properties. The conductivity spectra of the mixtures were described using a Jonscher fractal power law model characterized with three characteristic parameters, the dc conductivity ( σdc), the characteristic frequency ( fc) and an exponent ( n). Changes in effective stress, water content, clay content, and other engineering properties of the mixture such as dry density, porosity, pore size and intergranular void ratio are discussed with respect to changes in the electrical parameters. The dc conductivity and characteristic frequency decrease with an increase in effective stress levels. The exponent, however, has the opposite behavior and increases with an increase in effective stress. As the water content increases, σdc and fc increase while n decreases for all mixtures. With increasing stress levels, the average pore size of the mixtures decreases which results in a decrease in σdc and fc but an increase in the values of the exponent. An increase in dry density of the mixtures leads to a decrease in σdc and fc whilst n increases. Both σdc and fc increase with increase in the intergranular void ratio of the mixture whilst the exponent values decrease with an increase in the intergranular void ratio. This study serves as a contribution to our quest in utilizing electrical geophysical methods, to assess and monitor non-invasively, the geotechnical properties of the subsurface in a less expensive and faster manner.
Combined Monitoring Methods for Potential Landslides Using MRS and TEM
Authors: Lin Tingting , Lin Xiaoxue , Wan Ling , Guan Shanshan , Teng Fei
Published: December 2020

In this research study, the landslide events of Huangshan City in China's Anhui Province were monitored through the integration of two geophysical techniques: the magnetic resonance sounding (MRS) and transient electromagnetic (TEM) methods. The JLMRS-III system was used to determine the distributions of the free water in the strata and the MiniTEM system was utilized to image the subsurface electrical resistivity structures. Data acquisition was carried out on two planned survey lines during a wet season. A set of 15 measurements were completed using MRS array detection; a set of 44 measurements were completed using TEM method. The monitoring activities were repeatedly implemented before and after rainfall occurred. The results of water content information, relaxation time, and resistivity distributions were determined through joint inversion. Plots of the results clearly show the aquifer and resistivity structure of the study area. The monitoring data of displacement, pore-water pressure, and rainfall was collected to help differentiate the slip blocks, slip beds, and slip belts in the accumulation bodies of the landslides. We have delineated the potential landslide area, and determined the sliding depth range at 4 to 8 m. We analyzed the stability of the landslide based on the comparison of water content distribution and the relevant geological information in the sliding body to reveal the possibility of future destruction. The results of this study demonstrated that the combined techniques of MRS and TEM have the capability to effectively monitor potential landslides for key parameters needed for risk assessment.
Weighted Goal-oriented Adaptive Finite-element for 3D Transient EM Modeling
Authors: Qi Yanfu , Li Xiu , Yin Changchun , Qi Zhipeng , Zhou Jianmei , Liu Yunhe , Zhang Bo
Published: December 2020

The unstructured finite-element method has been widely used in 3D time-domain electromagnetic (EM) modeling due to its flexibility for modeling rugged topography and complex underground structures. However, how to generate high-quality grids becomes the key to high-accuracy EM responses. We have developed a weighted goal-oriented adaptive finite-element method based on hybrid posterior error estimation in combination with unstructured vector finite-element method and Backward Euler scheme to create an effective mesh. By introducing a weighting factor and adjusting the relative weights of the hybrid posterior errors, the numerical accuracy and convergence rate are greatly improved. To handle the huge difference of EM responses at different time channels, we introduce another weighting factor defined by the exponential power of time to achieve a synchronous refinement of shallow and deep meshes. The numerical experiments on a homogenous half-space model show that our algorithm performs better than the traditional adaptive method both from the accuracy and convergence. Further, we also test the effectiveness of our algorithm for modeling different abnormal bodies under a topographic earth.
Classification of Iron Meteorites with High Frequency Ultrasonic Waves
Authors: El Abassi Dris , Faiz Bouazza , Ibhi Abderrahmane , Aboudaoud Idris
Published: December 2020

We present the results of an ultrasonic pulse-echo technique and its potential to classify iron meteorites into hexahedrites, octahedrites and ataxites by determining their acoustic impedance and phase velocity. Our technique has been adapted from those used in the field of ultrasonic non-destructive investigation of a variety of materials. The main advantage of our technique is that it does not need any preparation of the meteorites like cutting and etching and therefore is rapid, easy and non-destructive. In essence, a broadband acoustic transducer is used in a monostatic pulse-echo configuration which means that both the transducer and the meteorite sample are located in a water bath and adjusted in the way that the ultrasonic pulse shit the meteorite sample at normal incidence. Then the reflected pulses from the front and rear faces of the meteorite sample are measured with the emitting transducer, digitally recorded and processed to analyze the signal. After Fourier transforming the echoed pulses from the front and the rear face of the meteorite sample, the calculated reflection coefficients yield the phase velocity and the acoustic impedance. Our study investigates a variety of iron meteorites collected in Morocco and other countries and it helps to understand how the nickel content of these meteorites affects the acoustic impedance. It reveals that the acoustic impedance of iron meteorites increases with increasing nickel content, so that a further refinement of our technique might have the potential to classify iron meteorites directly and reliably into hexahedrites, octahedrites and ataxites without destroying them.
Extracting Pseudo Wave Fields from Transient Electromagnetic Fields Using a Weighting Coefficients Approach
Authors: Xue Junjie , Cheng Jiulong , Xue Guoqiang , Li Hai , Hou Dongyang , Zhong Hua-Sen , Lei Kangxin , Li Xiu
Published: December 2020

The diffusive electromagnetic field can be transformed into the wave domain by means of mathematical conversion. The transformed field can then be interpreted with the tools in seismic data processing so that the identification to the underground targets can be effectively improved. However, the conversion is typically an ill-posed problem that needs to be solved using regularization tools. Based on the conventional regularization with smooth constraints in the L2 norm, the inversion result is of low resolution, while that obtained using truncated singular value decomposition (TSVD) methods is typically accurate, but has poor stability. To obtain a stable and accurate transformed electromagnetic field value, this study proposed to combine conventional regularization tools and singular value decomposition algorithms by incorporating a set of weighting coefficients. The proposed method is validated on both synthetic and observed data. The results from the proposed method are more accurate at the early time, and at the late time are more stable compared with the other methods. Furthermore, the example of field data shows that the proposed method could potentially further improve the interpretation accuracy of future mining explorations.
Feasibility of Monitoring Hydraulic Connections between Aquifers Using Time-lapse TEM: A Case History in Inner Mongolia, China
Authors: Chen Kang , Zhang Junyan , Xue Guoqiang , Huang Hao , Chen Weiying , Hao Jutao , Yue Yuezhen
Published: December 2020

Hydraulic connections between aquifers is usually studied through hydrochemical analysis or by pumping tests. However, hydrochemical analyses are usually conducted in areas of variable lithology. In addition, the hydrogeological data obtained by drilling and pumping tests are typically insufficient to get 3D distributions of hydraulic head. In this paper, the time-lapse transient electromagnetic method (TEM) is used to image groundwater migration between aquifers in Inner Mongolia, China. First, 1D geophysical models of aquifers are generalized according to the hydrogeological conditions of the region, and the feasibility of detecting the multiple aquifers by TEM is analyzed and discussed. Then, the 2D models of aquifers pre- and post- pumping test are established based on the distribution of groundwater in the aquifers, and the variation law of induced electromotive force measured on the surface is analyzed. The simulation results show that significant time-lapse electromagnetic anomalies can be observed between pre- and post- pumping test and the variation in the induced electromotive force reaches a distinguishable level between 0.7 ms and 100 ms due to the vertical change in the aquifer properties. Furthermore, the electromagnetic variation generated by hydraulic connection between aquifers is greater than 30% within the range of 3/4 of the transmitting loop. Finally, a successful case history to map hydraulic connections between aquifers is conducted using a time-lapse TEM pre- and post- a pumping experiment. This simulation and field experiment shows that time-lapse TEM could characterize and monitor the groundwater migration more effectively than pump tests or hydrogeochemical methods alone.
Polarity Change Extraction of GPR Data for Under-road Cavity Detection: Application on Sudeoksa Testbed Data
Authors: Hwang Jongha , Kim Donggeon , Li Xiangyue , Min Dong-Joo
Published: December 2020

Ground penetrating radar (GPR) is one of the most widely used geophysical survey methods to locate cavities under roads due to its speedy exploration and high-resolution imaging. To locate underground cavities using GPR, we need to distinguish between cavity-induced reflections and other reflections, which can be achieved by examining the polarity change in reflections compared to the polarity of the transmitted signal. The polarity change can be measured from the phase shift between the target and first reflections. To estimate the phase shift in reflections, the method of computing the power spectrum difference between the original trace and background signal was proposed, but the method has a limitation for shallow reflectors. As an alternative method to avoid this limitation, we propose using only one component of the power spectrum difference, the cross-correlation between the target reflection and background signal. The cross-correlation has its maximum peak at a time lag between the target and first reflection (from the air-ground interface). Additionally, the phase at that time lag represents a phase shift between the two reflections. We compare our cross-correlation-based method with the conventional method of computing the whole power spectrum difference and investigate the feasibility of our method for distinguishing cavity-induced reflections using a 2D field data set acquired in a testbed in Sudeoksa, Korea.
Quality Assessment of a Cut-Off Wall Dike Reinforcement by 2D-ERI
Authors: Fargier Yannick , Ananfouet Yannick , Lopes Sérgio Palma , Saussaye Lucile , Dore Ludovic , Jodry Clara , Fauchard Cyrille , Bièvre Grégory
Published: December 2020

Each year hydraulic structures such as levees and earth dams are hit by disorders that can lead to their collapse. A dike reinforcement method such as the deep soil mixing gets interest for its reinforcement capacity at moderate cost. We report on the use of a non-destructive technique to effectively assess the proper achievement of these structures and their evolution in time. More particularly, 2D-electrical resistivity imaging (2D-ERI) was used to assess a cut-off wall. We evaluate the benefits and limitations of three acquisition techniques (longitudinal, transversal and cross-hole). To complete the interpretation, we performed a comprehensive geotechnical study to make a diagnosis of the structure. Each inversion result is combined with numerical modelling that enlightens limitations of the acquisition techniques and improve the interpretation. Results show that 2D-ERI can present a real benefit for the assessment of cut-off walls even if the dimensions of the cut-off wall limit the detectability of deep heterogeneities.
Quantifying Erosion of Downhole Solids Control Equipment during Openhole, Multistage Fracturing
Authors: Dikshit Ashutosh , Woiceshyn Glenn , Agnihotri Vivek , Chochua Gocha , Noor Mohd Nazri Bin Md
Published: December 2020

Proppant flowback from hydraulic fracturing is widespread and costly due to erosion and/or blockage of producing hydrocarbons as proppant may accumulate downhole. Several strategies have been applied to avoid or minimize proppant flowback, such as treatment optimization to maximize pack stability, resin-coated proppant, limiting drawdown, or letting it flow to deal with the consequences later. Another strategy to avoid proppant flowback is to install sand control equipment integrated into a sliding sleeve device (SSD) as part of the completion string. Although the presence of sand control equipment can mitigate the problem, it raises concern about erosion during fracturing. Although some installations have been successful, one is known to have experienced sand control failure. This study aimed to understand the effect of hydraulic fracturing on the erosion of completion equipment with an objective of improving the design to, as much as possible, prevent erosion failure. Computational fluid dynamics (CFD) was used to evaluate the root cause and identify more robust design solutions.

The first step was to identify the most probable causes of sand control failure during multistage fracturing (MSF) in openhole (OH) horizontals. The as-is completion was then modeled, along with the screen, SSD, fracturing port, and OH isolation packer. Because the fracture location between two packers is unknown, and the fracturing port was located between multiple screen/SSD assemblies, annular flow across the assembly in both directions was considered. State-of-the-art CFD simulations were then performed on the installed design using actual flow conditions (rates, slurry properties, treatment time) from the failed installation. A new quasidynamic mesh (QDM) methodology was developed, which yielded more realistic (albeit still conservative) erosion-depth predictions. The results revealed areas for improving the design of key components of the 10-ksi-rated system, and CFD was rerun to confirm erosion resistance targets. Design modifications were implemented, and improved products were then manufactured and field tested. For a new 15-ksi design, particle–particle interaction was added to the CFD analysis. The results of the CFD analysis and field test are presented herein.
Lactobacillus Rhamnosus HDB1258 Modulates Gut Microbiota-Mediated Immune Response in Mice with or Without LPS-Induced Systemic Inflammation
Authors: Han Sang-Kap , Shin Yeon-Jeong , Lee Dong-Yeon , Kim Kyung Min , Yang Seo-Jin , Kim Du Seong , Choi Ji-Whi , Lee Seunghun , Kim Dong-Hyun
Published: December 2020

Background Gut microbiota closely communicate in the immune system to maintain a balanced immune homeostasis in the gastrointestinal tract of the host. Oral administration of probiotics modulates gut microbiota composition. In the present study, we isolated Lactobacillus rhamnosus HDB1258, which induced tumor necrosis factor (TNF)-α and interleukin (IL)-10 expression in macrophages, from the feces of breastfeeding infants and examined how HDB1258 could regulate the homeostatic immune response in mice with or without lipopolysaccharide (LPS)-induced systemic inflammation. Results Oral administration of HDB1258 significantly increased splenic NK cell cytotoxicity, peritoneal macrophage phagocytosis, splenic and colonic TNF-α expression, TNF-α to IL-10 expression ratio, and fecal IgA level in control mice, while Th1 and Treg cell differentiation was not affected in the spleen. However, HDB1258 treatment significantly suppressed peritoneal macrophage phagocytosis and blood prostaglandin E2 level in mice with LPS-induced systemic inflammation. Its treatment increased LPS-suppressed ratios of Treg to Th1 cell population, Foxp3 to T-bet expression, and IL-10 to TNF-α expression. Oral administration of HDB1258 significantly decreased LPS-induced colon shortening, myeloperoxidase activity and NF-κB+/CD11c+ cell population in the colon, while the ratio of IL-10 to TNF-α expression increased. Moreover, HDB1258 treatment shifted gut microbiota composition in mice with and without LPS-induced systemic inflammation: it increased the Cyanobacteria and PAC000664_g (belonging to Bacteroidetes) populations and reduced Deferribacteres and EU622763_s group (belonging to Bacteroidetes) populations. In particular, PAC001066_g and PAC001072_s populations were negatively correlated with the ratio of IL-10 to TNF-α expression in the colon, while the PAC001070_s group population was positively correlated. Conclusions Oral administered HDB1258 may enhance the immune response by activating innate immunity including to macrophage phagocytosis and NK cell cytotoxicity in the healthy host and suppress systemic inflammation in the host with inflammation by the modulation of gut microbiota and IL-10 to TNF-α expression ratio in immune cells. Keywords: Lactobacillus rhamnosus HDB1258; immunomodulation; immune enhancement; inflammation; gut microbiota.
Soil Aggregates Stability and Carbon Density Under Three Plantations on Loess Plateau, China
Authors: dong Lili , KOU Meng
Published: December 2020

[Background] This paper aimed to research the influence of types of plantations on soil aggregate stability and carbon density. The soils of Robinia pseudoacacia, Pinus tabulaeformis and M. pumila plantations were selected as the research objects in the south of Loess Plateau. The mass percentages of soil water stable aggregates with different sizes were measured by fast wetting method, and then, the mean weight diameter (MWD) was calculated to asses soil aggregate stability. Soil organic carbon, inorganic carbon and bulk density were analyzed using traditional analysis methods. The roles played by soil organic and inorganic carbon in the formation of water stable aggregates were discussed. [Results] The content of soil organic carbon and MWD was significantly higher in P. tabuliformis plantation compared with R. pseudoacacia and M. pumila plantations. Conversely, the content of soil calcium carbonate and total carbon density was the lowest in P. tabuliformis plantation. Soil organic carbon was the highest at the surface soils (0-10 cm), which was 2.21-3.96, 2.10-3.00 and 1.65-2.53 times compared with subsurface soils in Robinia pseudoacacia, Pinus tabulaeformis and M. pumila plantations respectively. While soil carbonate calcium and inorganic carbon density fluctuated with the increasing of soil layers. Aggregate organic carbon increased while carbonate calcium content decreased with the increasing of aggregate size respectively. [Conclusion] We concluded that: (1) P. tabuliformis played a more important role in soil organic carbon sequestration compared with R. pseudoacacia and M. pumila; (2) there was a threshold value of carbonate calcium content, when it was lower or higher than this threshold, it had positive or negative correlation with MWD; (3) bigger water stable aggregates had higher soil organic matter and lower carbonate calcium.
Association Between ZFHX3 and PRRX1 Genes’ Two Common Polymorphisms and Atrial Fibrillation Susceptibility in Asians
Authors: Wu Liting , Chu Ming , Zhuang Wenfang
Published: December 2020

BackgroundOne of the common sustained cardiac arrhythmia disorders is atrial fibrillation (AF), nowadays, results concerning the associations between ZFHX3/PRRX1 genes and AF has been widely reported. A meta-analysis to confirm above associations is necessary to be carried out in time. MethodsThe PubMed, Embase and Wanfang databases were conducted for searching, covering all publications before 20th July, 2020. ResultsOverall, seven articles including 3,674 cases and 8,990 healthy controls about ZFHX3 rs2106261 and 1045 cases and 1407 controls for PRRX1 rs3903239 were included. Odds ratio (OR)[95% confidence interval (CI)] was applied to assess the associations. Publication bias was calculated by both Egger’s and Begg’s tests. After calculated, we found that ZFHX3 rs2106261 polymorphism potential increased AF risk in Asians (for example: allelic contrast: OR [95%CI]: 1.39[1.31-1.47], P < 0.001). Similarly, stratified analysis by source of control and genotype method, also increased associations were detected (for example: allelic contrast: OR[95%CI] = 1.51[1.38-1.64], P < 0.001 for HB; OR[95%CI]: 1.31[1.21-1.41], P < 0.001 for PB; OR[95%CI] = 1.55[1.33-1.80], P < 0.001 for TaqMan; OR[95%CI] = 1.31[1.21-1.41], P < 0.001 for HRM). On the other hand, decreased relationship was observed between PRRX1 rs3903239 polymorphism and AF risk (C-allele vs. T-allele: OR[95%CI] = 0.83[0.77-0.99], P = 0.036; CT vs. TT: OR[95%CI] = 0.79[0.67-0.94], P = 0.006). No obvious evidence of publication bias was found. Conclusions﻿In summary, our study suggested that ZFHX3 rs2106261 and PRRX1 rs3903239 polymorphisms had positive associations with AF risk, more large case-controls must be carried out to confirm above conclusions.
Differences in Upper Quarter Y Balance Test Performance According to Playing Position in Youth Handball Players
Authors: Bauer Julian , Schwiertz Gerrit , Muehlbauer Thomas
Published: December 2020

Objective

Handball is an Olympic intermittent sport with different playing positions that can be differentiated between first line players who positions themselves near the 6-m line and second line players who typically play outside the 9-m space. Additionally, goalkeepers have a distinctive role as they mostly only play within their own 6-m space. The objective of the study was to assess whether the specific physiological positional demands in handball lead to functional performance differences between the playing positions in terms of shoulder mobility and stability in any reach direction as assessed through the Upper Quarter Y Balance Test (YBT-UQ).
Results

No significant differences in any reach direction of the YBT-UQ were found between the playing positions, irrespective of reach arm and reach direction. The obtained effect sizes (ηp2) were solely small and ranged between .003 and .030.
Neighborhood-Level Public Facilities and COVID-19 Transmission: A Nationwide Geospatial Study In China
Authors: Jin Xurui , Leng Yu , Gong Enying , Xiong Shangzhi , Yao Yao , Vedanthan Rajesh , Yang Zhenchun , Chen Keren , Wu Chenkai , Yan Lijing
Published: December 2020

Background: Individual-level studies on the coronavirus disease 2019 (COVID-19) have proliferated, however, research on neighborhood-level factors associated with COVID-19 is limited. Our study aim at examining the assocaiton between having COVID-19 cases in the neighborhood and public facilities.Methods: We gathered the geographic data of all publically released COVID-19 cases in China and the point-of-interests data from Gaode map including restaurant, shopping center, hotels, living facilities, recreational facilities, public transit, reducation and health services. We used a case-control design (1:4 ratio; 4,329 cases vs. 17,316 controls) to investigate the association between having COVID-19 cases in the neighborhood and the number and types of public facilities nearby. Results: In the multivariable logistics regression model, having more restaurants (high vs. low, OR: 2.09, 95% CI: 1.95, 2.25), shopping centers (OR: 2.27, 95% CI: 2.12, 2.43), hotels (OR: 2.32, 95% CI: 2.16, 2.48), living facilities (OR: 1.82, 95% CI: 1.70, 1.95), recreational facilities (OR: 2.27, 95% CI: 2.11, 2.43), public transit (OR: 1.32, 95% CI: 1.23, 1.41), educational institutions (OR: 1.96, 95% CI: 1.83, 2.10), and health service facilities (OR: 4.12, 95% CI: 3.83, 4.44) was associated with significantly higher odds of having COVID-19 cases in a neighborhood. The associations for restaurants, hotels, reactional and education facilities were more pronounced in cities with fewer than six million people than those in larger cities (Psinteraction <0.05).Conclusions: Our results have implications for designing targeted prevention strategies at the neighborhood level to reduce the burden of COVID-19.
The Best Strategy for Nasogastric Tube Removal in Patients with Acute Appendicitis Complicated with Ileus: A Case Report and Review.
Authors: Tseng Yu-Ju , Huang Pei-Yin , Lee Po-Chu , Lin Tzu-Hsin , Hu Rey-Heng
Published: December 2020

BackgroundAcute appendicitis is one of the most common causes of the acute abdomen. However, acute appendicitis complicated with ileus is uncommon. By presenting this case, we aim to give some suggestions on the postoperative care, especially an algorithm for the insertion and removal of nasogastric tube.Case presentation A 20-year-old man presenting with left lower abdominal pain and symptoms of ileus was diagnosed with acute appendicitis complicated with ileus by computed tomography scan. A nasogastric tube was inserted for the ileus preoperatively. He underwent laparoscopic appendectomy, during which periappendiceal abscess with local peritonitis was noted. The nasogastric tube was removed on the first postoperative day, but symptoms of ileus developed again. Urografin study revealed contrast media retaining in the small bowel, so nasogastric tube reinsertion was performed. The nasogastric tube was removed on the ninth postoperative day after the recovery from ileus. The patient was discharged on the thirteenth postoperative day.ConclusionPatients of acute appendicitis with ileus should be assessed carefully. Nasogastric tubes shouldn’t be removed until the following requirements are satisfied: Firstly, symptoms of abdominal distention and nausea relieve. Secondly, no more hypoactive bowel sounds are found. And finally, nasogastric tube drainage becomes less than 200mL per day, or the passage of flatus or stool presents.
Study of the Comparison of Endoscopic Closure and Laparoscopic Repair of Defect of Gastric Wall
Authors: Qiao Qiao , Tu Huiming , Fei Bojian , Xu Kebin , Yang Fan , Li Jie , Gao Qizhong
Published: December 2020

Objective: To make analysis on the curative effect on the technique of endoscopic closure and laparoscopic closure, and explore the effect and safety of acute perforation of the endoscopic closure technique. Methods: Analysis on the 40 therapeutic cases of laparoscopic repair and endoscopic closure treatments, respectively, to submucosal tumours (SMT) of the stomach removed through ESE/EFR. According to the double-sample t-test, the differences of operation time and medical expenses between the two closure methods were compared and analyzed. And used the chi-square test to compare the difference in terms of operational difficulty and effects. Results: Postoperative pathology of 76 therapeutic cases operated through ESE and EFR was diagnosed as mesenchymal tumor and 4 cases as leiomyoma, among which 34 cases were in fundus ventriculi, 30 in corpus ventriculi and 16 in antrum. Endoscopic closure is significantly lower than laparoscopic closure in operation time span (endoscopic closure VS laparoscopic repair 74.70±23.55min vs 178.35±38.98min, p < 0.001) , medical expenses (endoscopic closure VS laparoscopic repair 28463.55±8228.96rmb vs 61848.75±8812.12rmb, p < 0.001) and inpatient days (endoscopic closure VS laparoscopic repair 10.50±3.49days vs. 16.95±4.58days, P < 0.01), while there is no significant difference in terms of technical difficulty and effects (P > 0.05). Conclusion: With the training and technical progress of endoscopic closure, it is safe, effective and quick in recovery to have non-laparoscopic assisted surgery on gastric wall closure.
WITHDRAWN: Near-infrared Intraoperative Imaging of Pelvic Autonomic Nerves: Clinical Trial
Authors: Jin Hao , Lu Ligong , Cui Min
Published: December 2020

Background: The pelvic autonomic nerves control and regulate anorectal and urogenital function. The dysfunction of pelvic autonomic nerves lead to disorders of anorectum, bladder and male sex organs. Thus the intraoperative identification of pelvic autonomic nerves could be crucial in complications prevention and diseases treatment. Our clinical trial aims at estimating the effectiveness and validity of intraoperative indocyanine green fluorescence imaging in pelvic autonomic nerves identification.Methods: Intraoperative fluorescence imaging using indocyanine green was performed in 10 patients and the feasibility was determined. From February 2019 to June 2019, the 10 patients undergoing laparoscopic colorectectomy was administrated 4.5 mg/Kg indocyanine green 24 hours before surgery. The near-infrared fluorescence imaging was conducted during surgery. A novel white light and near-infrared dual-channel laparoscopic equipment was applied. For each patient, signal background ratio values for pelvic autonomic nerves were recorded and analyzed.Results: We confirmed the best dose and timing of indocyanine green administration was 4.5 mg/Kg and 24 hours before surgery. Using the dual laparoscopic equipment, we could observe the splanchnic plexus, inferior mesenteric artery plexus, and sacral plexus successfully with a high signal background ratio value of 3.18 (standard deviation: 0.48). Conclusion: Pelvic autonomic nerves could be observed using indocyanine green fluorescence imaging during surgery. The novel method may replace the current visual identification method and become the standard clinical practice.
Exploration and Verification of a Six-RNA Binding Proteins-based Prognosis Evaluating Model for Hepatocellular Carcinoma
Authors: Chen Miao , Li Shujie , Zhang Jiakang , Han Jianbo , Wang Lili , Yin Dandan , Yi Changhua , Yi Yongxiang
Published: December 2020

BackgroundRNA binding protein (RBP) plays a crucial role in tumorigenesis at post-transcriptional level in various cancer types. Nevertheless, the role of RBPs in liver hepatocellular carcinoma (LIHC) remains obscure. We attempted to uncover the association between RBPs and the prognosis of LIHC patients. MethodsWe analyzed the transcriptome and corresponding clinical data of LIHC patients from the cancer genome atlas (TCGA) (training cohort) and international cancer genome consortium (ICGC) (validating cohort) database with a series of bioinformatics methods. Differently expressed RNA-binding proteins (DERBPs) were screened and subjected to functional enrichment analysis and co-expression network establishment. Overall survival (OS) related DERBPs and our prognosis risk model were confirmed by univariate, LASSO and multivariate regression analysis in training cohort. Survival analysis, Receiver operating characteristic curve (ROC) and nomogram were conducted in both training and validating groups to confirm the performance of our model. Human protein atlas (HPA) database and Kaplan-Meier plotter were used to verify the expression and prognostic significance of the hub RBPs respectively.Results There were 330 RBPs were found significantly different in TCGA. Functional analysis indicated most of the DERBPs were majored in RNA processing, alternative splicing and metabolism, etc. 6 RBPs (UPF3B, MRPL54, ZC3H13, DHX58, PPARGC1A, EIF2AK4) were recognized as OS related and enrolled into our prognostic model. Survival analysis showed the risk signature was negatively correlated with the OS of LIHC patients in both training (p = 5.808e-06) and validating (p = 3.38e-03) groups. The area under curves (AUC) of the receiver operating characteristics (ROC) curve in training and validating cohorts was 0.756, 0.781 respectively which indicating the good performance of our model. The risk signature was an independent hazardous factor in multivariate COX regression analysis either in TCGA (HR = 1.626;95% CI 1.394 -1.897, p < 0.001) or ICGC (HR = 1.939;95% CI 1.324 -2.838, p < 0.001). Nomogram and calibration curve indicated our model had best performance in predicting 3-year survival rate.ConclusionsWe constructed a six-RBPs based risk signature model which had moderate efficiency in LIHC patients’ prognosis forecasting which may assist practitioners to make better decision in the management of LIHC.