Chinese herbal medicine Ginkgo biloba L. preparations for ischemic stroke: An overview of systematic reviews and meta-analyses.

BACKGROUND: Ginkgo biloba L. preparations (GBLPs) are a class of Chinese herbal medicine used in the adjuvant treatment of ischemic stroke (IS). Recently, several systematic reviews (SRs) and meta-analyses (MAs) of GBLPs for IS have been published. OBJECTIVE: This overview aims to assess the quality of related SRs and MAs. SEARCH STRATEGY: PubMed, Embase, Cochrane Library, Web of Science, Chinese Biological Medicine, China National Knowledge Infrastructure, Wanfang, and Chinese Science and Technology Journals databases were searched from their inception to December 31, 2022. INCLUSION CRITERIA: SRs and MAs of randomized controlled trials (RCTs) that explored the efficacy of GBLPs for patients with IS were included. DATA EXTRACTION AND ANALYSIS: Two independent reviewers extracted data and assessed the methodological quality, risk of bias (ROB), reporting quality, and credibility of evidence of the included SRs and MAs using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), Risk of Bias in Systematic Reviews (ROBIS), the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE), respectively. Additionally, descriptive analysis and data synthesis were conducted. RESULTS: Twenty-nine SRs/MAs involving 119 outcomes were included in this review. The overall methodological quality of all SRs/MAs was critically low based on AMSTAR 2, and 28 had a high ROB based on the ROBIS. According to the PRISMA statement, the reporting items of the included SRs/MAs are relatively complete. The results based on GRADE showed that of the 119 outcomes, 8 were rated as moderate quality, 24 as low quality, and 87 as very low quality. Based on the data synthesis, GBLPs used in conjunction with conventional treatment were superior to conventional treatment alone for decreasing neurological function scores. CONCLUSION: GBLPs can be considered a beneficial supplemental therapy for IS. However, because of the low quality of the existing evidence, high-quality RCTs and SRs/MAs are warranted to further evaluate the benefits of GBLPs for treating IS. Please cite this article as: Meng TT, You YP, Li M, Guo JB, Song XB, Ding JY, Xie XL, Li AQ, Li SJ, Yin XJ, Wang P, Wang Z, Wang BL, He QY. Chinese herbal medicine Ginkgo biloba L. preparations for ischemic stroke: An overview of systematic reviews and meta-analyses. J Integr Med. 2024;22(2): 163-179.

Rubidium isotopic compositions of angrites controlled by extensive evaporation and partial recondensation.

The planetesimals in the solar system exhibit varying degrees of moderately volatile elements (MVEs) depletion compared to the protosolar composition. Revealing the relevant mechanisms is crucial for exploring early solar system evolution. Most volatile-depleted materials in the solar system exhibit enrichments in the heavier isotopes of MVEs, which have traditionally been attributed to the loss of volatiles through partial evaporation. Angrites are so far an exception as they are enriched in the lighter isotopes of K. This has been interpreted as reflecting condensation processes. Here, we present Rb isotopic data of angrites and find that they have lighter Rb isotopic compositions than Vesta, Mars, and the Moon. The δ87Rb value of the angrite parent body (APB) is estimated to range between -1.19‰ and -0.67‰. The extremely light Rb isotopic composition of the APB is likely a result of the kinetic recondensation of Rb after near-complete evaporation during the magma ocean stage. This finding provides further support for the partial recondensation model to explain the light Rb and K isotopic compositions of the APB. In addition, the APB, alongside other terrestrial planetary bodies (e.g., Earth, Mars, Moon, and Vesta), exhibit a strong correlation between their Rb and K isotopic compositions. This coupling of Rb and K isotopes is indicative of a volatility-driven isotopic fractionation rather than nucleosynthetic anomalies. The extremely light Rb-K isotopic signatures of the APB suggest that beyond evaporation, condensation plays an equally significant role in shaping the planetary-scale distributions of volatile elements.

Preparation of Superhydrophobic Fabric Based on Dopamine and Michael Addition under Ultraviolet Light.

This work reports a simple, stable, and environmentally friendly method to prepare durable superhydrophobic surfaces. First, a polydopamine coating is formed by oxidative polymerization of dopamine to form a secondary reaction platform to provide reaction sites for subsequent experiments. We applied a polydopamine layer onto a fiber surface using the Michael addition-reaction-grafted tetrakis (3-mercaptopropionic acid) pentaerythritol ester, followed by the introduction of tetraallyl silane and (mercapto) methyl siloxane-dimethyl siloxane copolymer on the polydopamine by a thiol-ene click-reaction under ultraviolet light. The resulting superhydrophobic Nylon 56 fabric exhibited a 166° static contact angle as well as excellent stability. The surface morphology of all samples was observed by field emission scanning electron microscope, X-ray photoelectron spectroscopy and energy dispersion spectroscopy, and the elemental composition and surface chemical state of the samples were analyzed. It also had the ability of oil-water separation. Fabric with such benefits broadens the applicability and innovation of superhydrophobic textiles for environmental and industrial applications.

Evolution and attribution of ecological flow in the Xiangjiang River basin since 1961.

Climate change and human activities have greatly altered the ecological flow of rivers, and the conflict between human water use and natural water demand is becoming more and more prominent. Using two ecological flow indicators (ecodeficit and ecosurplus), this study focuses on assessing the characteristics of ecological flow changes at multiple time scales and introduces the Long Short-Term Memory model to construct a meteorological streamflow model for the Xiangjiang River (XJR) basin, using a separation framework to quantify the effects of human disturbance and climate change on ecological flow at multiple time scales. In addition, the fluvial biodiversity Shannon Index (SI) was used to assess the response processes of riverine ecosystems under changing conditions. The results show that the increase of XJR flow is larger (11%) after 1991, the increase in precipitation and potential evapotranspiration in the basin is 5.60%, and the decrease is 3.09%, respectively, and there are obvious cycles of all three on annual and seasonal scales. The annual ecosurplus increased, and the annual ecodeficit decreased after the hydrological variation; on the seasonal scale, the ecodeficit decreased significantly in summer and autumn, and the ecosurplus increased substantially in winter. Climatic factors were the main drivers of the increased frequency and magnitude of annual, summer, and fall high flows (91%, 94%, and 65% contributions, respectively), while urbanization expansion and reservoir diversions drove the increase in spring ecodeficit. Changes in river flow maintained the ecosurplus at a low level after 2002, further causing a decrease in river biodiversity, and the annual and summer ecosurplus were highly correlated with SI indicators (0.824 and 0.711, respectively). Our study contributes to the development of effective ecological flow regulation policies for the XJR basin.

Recent Progress in Multiple Sclerosis Treatment Using Immune Cells as Targets.

Multiple sclerosis (MS) is an autoimmune-mediated demyelinating disease of the central nervous system. The main pathological features are inflammatory reaction, demyelination, axonal disintegration, reactive gliosis, etc. The etiology and pathogenesis of the disease have not been clarified. The initial studies believed that T cell-mediated cellular immunity is the key to the pathogenesis of MS. In recent years, more and more evidence has shown that B cells and their mediated humoral immune and innate immune cells (such as microglia, dendritic cells, macrophages, etc.) also play an important role in the pathogenesis of MS. This article mainly reviews the research progress of MS by targeting different immune cells and analyzes the action pathways of drugs. The types and mechanisms of immune cells related to the pathogenesis are introduced in detail, and the mechanisms of drugs targeting different immune cells are discussed in depth. This article aims to clarify the pathogenesis and immunotherapy pathway of MS, hoping to find new targets and strategies for the development of therapeutic drugs for MS.

Distributed Optical Measurement System for Plate Fin Heat Exchanger.

The acquirement of the flow information in plate-fin heat exchanger (PFHE) is limited by its metal structure and complex flow condition. This work develops a new distributed optical measurement system to obtain flow information and boiling intensity. The system utilizes numerous optical fibers installed at the surface of the PFHE to detect optical signals. The attenuation and fluctuation of the signals reflect the variation of the gas-liquid interfaces and can be further used to estimate the boiling intensity. Practical experiments of flow boiling in PFHE with different heating fluxes have been carried out. The results verify that the measurement system can obtain the flow condition. Meanwhile, according to the results, the boiling development in PFHE can be divided into four stages with the increase in the heating flux, including the unboiling stage, initiation stage, boiling developing stage, and fully developed stage.

Systematic review and meta-analysis of reflexology for people with multiple sclerosis: Systematic Review and Meta-Analysis.

BACKGROUND: Research on reflexology therapy for multiple sclerosis (MS) is limited, and the evaluation is mixed. Our aim is to confirm the efficacy of reflexology therapy for MS. METHODS: The preferred reporting items for systematic reviews and meta-analyses guidelines were followed. The search strategy was conducted in PubMed, Embase, the Cochrane Library, and the Science Citation Index. The quality of the included trials was assessed by the Cochrane Handbook. The main results were summarized and analyzed in RevMan 5.4. RESULTS: A total of 11 studies were included in the final analysis. There were significant differences [mean difference (MD) -0.90, 95% confidence interval (CI) -1.37 to -0.43, heterogeneity I2  = 0%] between the Precision Reflexology and Sham Reflexology groups in visual analogue scale pain. There was a significant difference (MD -1.00, 95% CI -1.42 to -0.58, heterogeneity I2  = 93%) between the Precision Reflexology and Sham Reflexology groups on the fatigue severity scale. There was no difference between the Precision Reflexology and Sham Reflexology groups in physical function (MD 6.88, 95% CI -3.36 to 17.13, heterogeneity I2  = 31%), role disorder due to physical problems (MD 10.20, 95% CI -4.91 to 25.30, heterogeneity I2  = 0%), physical pain (MD 7.68, 95% CI -0.09 to 15.45, heterogeneity I2  = 0%), role disorder due to emotional problems (MD 3.41, 95% CI -11.55 to 18.37, heterogeneity I2  = 0%), energy (MD 3.27, 95% CI -4.32 to 10.87, heterogeneity I2  = 0%), emotional well-being (MD 1.79, 95% CI -4.76 to 8.34, heterogeneity I2  = 0%), social function (MD 5.72, 95% CI -3.48 to 14.91, heterogeneity I2  = 0%), or general health (MD 2.63, 95% CI -4.36 to 9.62, heterogeneity I2  = 0%). CONCLUSIONS: Reflexology therapy can be used as an effective intervention for the pain and fatigue of MS patients while improving the quality of life.

On the Image Reconstruction of Capacitively Coupled Electrical Resistance Tomography (CCERT) with Entropy Priors.

Regularization with priors is an effective approach to solve the ill-posed inverse problem of electrical tomography. Entropy priors have been proven to be promising in radiation tomography but have received less attention in the literature of electrical tomography. This work aims to investigate the image reconstruction of capacitively coupled electrical resistance tomography (CCERT) with entropy priors. Four types of entropy priors are introduced, including the image entropy, the projection entropy, the image-projection joint entropy, and the cross-entropy between the measurement projection and the forward projection. Correspondingly, objective functions with the four entropy priors are developed, where the first three are implemented under the maximum entropy strategy and the last one is implemented under the minimum cross-entropy strategy. Linear back-projection is adopted to obtain the initial image. The steepest descent method is utilized to optimize the objective function and obtain the final image. Experimental results show that the four entropy priors are effective in regularization of the ill-posed inverse problem of CCERT to obtain a reasonable solution. Compared with the initial image obtained by linear back projection, all the four entropy priors make sense in improving the image quality. Results also indicate that cross-entropy has the best performance among the four entropy priors in the image reconstruction of CCERT.

Circ_TLK1 knockdown alleviates oxygen-glucose deprivation/reoxygenation-induced PC12 cell injury by regulating microRNA-136-5p/follistatin like-1 axis.

BACKGROUND: Circular RNAs (circRNAs) are aberrantly expressed in the central nervous system (CNS) and are involved in diverse CNS diseases. However, the functions of circRNAs in ischemic stroke (IS) are largely unknown. In this study, we aimed to explore the effect of circ_TLK1 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced PC12 cell injury. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for the levels of circ_TLK1, TLK1, microRNA-136-5p (miR-136-5p), and follistatin like-1 (FSTL1). RNase R and Actinomycin D assays were conducted to analyze the features of circ_TLK1. 3-(4, 5-ethynyl-2'-deoxyuridine [EdU] assay and 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay were adopted to analyze cell proliferation capacity. Flow cytometry analysis was applied to determine cell death. Western blot assay was employed to measure protein levels. The release of lactate dehydrogenase (LDH) was measured with specific kits. The interaction between circ_TLK1 and miR-136-5p, as well as miR-136-5p and FSTL1, was verified by Dual-luciferase reporter assay. RESULTS: Circ_TLK1 was upregulated in OGD/R-injured PC12 cells. OGD/R treatment inhibited cell proliferation, promoted cell death, and increased LDH release in PC12 cells, while circ_TLK1 knockdown partially alleviated OGD/R-induced PC12 cell injury. Circ_TLK1 directly bound to miR-136-5p and miR-136-5p inhibition reversed the effect of circ_TLK1 knockdown on OGD/R-induced PC12 cell damage. Moreover, FSTL1 was targeted by miR-136-5p. MiR-136-5p upregulation inhibited PC12 cell injury induced by OGD/R, while FSTL1 overexpression partially reversed the effect. CONCLUSION: Circ_TLK1 knockdown ameliorated OGD/R-induced PC12 cell injury by modulating miR-136-5p and FSTL1, which might provide a new understanding of IS treatment.

A New Adaptive GCC Method and Its Application to Slug Flow Velocity Measurement in Small Channels.

In this work, an adaptive generalized cross-correlation (AGCC) method is proposed that focuses on the problem of the conventional cross-correlation method not effectively realizing the time delay estimation of signals with strong periodicity. With the proposed method, the periodicity of signals is judged and the center frequencies of the strongly periodical components are determined through the spectral analysis of the input signals. Band-stop filters that are used to suppress the strongly periodical components are designed and the mutual power spectral density of the input signals that is processed by the band-stop filters is calculated. Then, the cross-correlation function that is processed is the inverse Fourier transform of the mutual power spectral density. Finally, the time delay is estimated by seeking the peak position of the processed cross-correlation function. Simulation experiments and practical velocity measurement experiments were carried out to verify the effectiveness of the proposed AGCC method. The experimental results showed that the new AGCC method could effectively realize the time delay estimation of signals with strong periodicity. In the simulation experiments, the new method could realize the effective time delay estimation of signals with strong periodicity when the energy ratio of the strongly periodical component to the aperiodic component was under 150. Meanwhile, the cross-correlation method and other generalized cross-correlation methods fail in time delay estimation when the energy ratio is higher than 30. In the practical experiments, the velocity measurement of slug flow with strong periodicity was implemented in small channels with inner diameters of 2.0 mm, 2.5 mm and 3.0 mm. With the proposed method, the relative errors of the velocity measurement were less than 4.50%.

Preparation of Stable POSS-Based Superhydrophobic Textiles Using Thiol-Ene Click Chemistry.

In this study, a superhydrophobic fabric was synthesized by modifying the fiber's surface with dopamine-containing hydroxyl functional groups. Furthermore, we introduced mercapto-based functional groups by the hydrolysis of mercaptopropylmethyldimethoxysilane (MPMDS) and finally grafted POSS and mercaptans using a thiol-ene click reaction. These processes generated a superhydrophobic fabric with a static contact and a sliding angle of 162° and 8°, respectively. The superhydrophobic fabric's compact and regular micro-nano rough structure based on POSS and mercaptans provides stable fastness and durability, as well as high resistance to organic solvents, acid-base environments, mechanical abrasion, UV rays, and washing. Moreover, it can be used for self-cleaning and oil-water separation, and it has a wide range of applications in the coating industry.

microRNA-133a exerts tumor suppressive role in oral squamous cell carcinoma through the Notch signaling pathway via downregulation of CTBP2.

microRNAs (miRNAs) have been revealed to participate in some oral cancers and are proved to be effective. In the present study, we tried to explore the biological function of miR-133a in oral squamous cell carcinoma (OSCC) cells. The relationship that C-terminal-binding proteins 2 (CTBP2) was the putative target gene of miR-133a revealed from bioinformatics analysis was further was further validated by dual-luciferase reporter gene assay. In total, 40 patients with OSCC were enrolled for characterization of miR-133a, CTBP2, and Notch signaling pathway-related gene expression in clinical OSCC tissues. Low expression of miR-133a and high expression of CTBP2, Hes1, Notch-1, and Notch-3 were determined in OSCC tissues. OSCC cell lines were transfected with miR-133a inhibitor, miR-133a mimic, or shRNA targeting CTBP2, in response to which cell proliferation, migration, invasion, cell cycle, and apoptosis were evaluated. Transfection of miR-133a mimic induced apoptosis and inhibited OSCC cell proliferation, migration, and invasion and this was demonstrated to be attributable to decreased CTBP2 expression and suppression of the Notch signaling pathway. Taken together, we concluded that miR-133a acted as a tumor suppressor in OSCC through inhibition of the Notch signaling pathway via binding to CTBP2.

A Low Excitation Working Frequency Capacitively Coupled Contactless Conductivity Detection (C4D) Sensor for Microfluidic Devices.

In this work, a new capacitively coupled contactless conductivity detection (C4D) sensor for microfluidic devices is developed. By introducing an LC circuit, the working frequency of the new C4D sensor can be lowered by the adjustments of the inductor and the capacitance of the LC circuit. The limits of detection (LODs) of the new C4D sensor for conductivity/ion concentration measurement can be improved. Conductivity measurement experiments with KCl solutions were carried out in microfluidic devices (500 µm × 50 µm). The experimental results indicate that the developed C4D sensor can realize the conductivity measurement with low working frequency (less than 50 kHz). The LOD of the C4D sensor for conductivity measurement is estimated to be 2.2 µS/cm. Furthermore, to show the effectiveness of the new C4D sensor for the concentration measurement of other ions (solutions), SO42- and Li+ ion concentration measurement experiments were also carried out at a working frequency of 29.70 kHz. The experimental results show that at low concentrations, the input-output characteristics of the C4D sensor for SO42- and Li+ ion concentration measurement show good linearity with the LODs estimated to be 8.2 µM and 19.0 µM, respectively.

A method for void fraction measurement of bubble/slug flow in small channels based on contactless impedance detection.

The flow parameter measurement of the gas-liquid two-phase flow in small channels is very crucial and challenging in both academia and industry. Conventional techniques based on radiations, optics, acoustics, or electrics most lose their superiorities in the scenario with small channels due to the spatial limitation and the online and contactless measurement requirements. In addition, the conductive characteristic of the two-phase flow is equivalent to an impedance rather than a resistance due to the existence of multi-phases. The equivalent impedance information of the two-phase flow, especially the imaginary part, is promising to provide more flowing details but has seldom been detected or analyzed. In this paper, a method for the void fraction measurement of bubble/slug flow in small channels is proposed. The method implements void fraction measurement in a contactless way, based on the acquisition of the total impedance information of the gas-liquid two-phase flow. First, a new contactless impedance detection sensor is designed, based on the simulated inductor technique and the analog phase sensitive demodulation technique, to obtain the complete equivalent impedance information of the two-phase fluid. Then, based on the flow pattern identification result, the void fraction measurement model is developed, which is a fusion of the relationships between the void fraction and the real part/the imaginary part of the equivalent impedance information, respectively. Experimental results on prototypes with different inner diameters (2.48, 3.64, and 4.52 mm, respectively) validate the effectiveness of the proposed void fraction method. The maximum void fraction measurement biases are within 5.0%.

Investigation of the Effects of Electrode Geometry on the Performance of C4D Sensor with Radial Configuration.

Electrodes are basic components of C4D (capacitively coupled contactless conductivity detection) sensors, and different electrode structures (the configuration pattern or the electrode geometry) can lead to different measurement results. In this work, the effects of electrode geometry of radial configuration on the measurement performance of C4D sensors are investigated. Two geometrical parameters, the electrode length and the electrode angle, are considered. A FEM (finite element method) model based on the C4D method is developed. With the FEM model, corresponding simulation results of conductivity measurement with different electrode geometry are obtained. Meanwhile, practical experiments of conductivity measurement are also conducted. According to the simulation results and experimental results, the optimal electrode geometry of the C4D sensor with radial configuration is discussed and proposed. The recommended electrode length is 5-10 times of the pipe inner diameter and the recommended electrode angle is 120-160°.

Circular RNA circ_HECTD1 regulates cell injury after cerebral infarction by miR-27a-3p/FSTL1 axis.

Cerebral infarction is a common cerebrovascular disease caused by neural cell injury, with high mortality worldwide. Circular RNAs HECT domain E3 ubiquitin-protein ligase 1 (circ_HECTD1) has been reported to be related to the oxygen-glucose deprivation/reperfusion (OGD/R)-caused neuronal damage in cerebral ischemia. This study is designed to explore the role and mechanism of circ_HECTD1 in OGD/R-induced cell injury in cerebral ischemia. Circ_HECTD1, microRNA-27a-3p (miR-27a-3p), and Follistatin-like 1 (FSTL1) level were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The localization of circ_HECTD1 was analyzed by subcellular fractionation assay. Cell proliferative ability and apoptosis were assessed by 5-ethynyl-2'-deoxyuridine (EdU), 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), and flow cytometry assays. The protein levels of proliferating cell nuclear antigen (PCNA), B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), Cleaved poly-ADP-ribose polymerase (PARP), and FSTL1 were examined by western blot assay. The binding relationship between miR-27a-3p and circ_HECTD1 or FSTL1 was predicted by starbase 3.0 then verified by a dual-luciferase reporter assay. Circ_HECTD1 and FSTL1 were highly expressed, and miR-27a-3p was decreased in OGD/R-treated HT22 cells. Moreover, circ_HECTD1 knockdown could boost cell proliferative ability and repress apoptosis in OGD/R-triggered HT22 cells in vitro. Mechanical analysis discovered that circ_HECTD1 could regulate FSTL1 expression by sponging miR-27a-3p. Circ_HECTD1 deficiency could mitigate OGD/R-induced HT22 cell damage by modulating the miR-27a-3p/FSTL1 axis, providing a promising therapeutic target for cerebral infarction treatment.

Self-Amplification of Coherent Energy Modulation in Seeded Free-Electron Lasers.

The spectroscopic techniques for time-resolved fine analysis of matter require coherent x-ray radiation with femtosecond duration and high average brightness. Seeded free-electron lasers (FELs), which use the frequency up-conversion of an external seed laser to improve temporal coherence, are ideal for providing fully coherent soft x-ray pulses. However, it is difficult to operate seeded FELs at a high repetition rate due to the limitations of present state-of-the-art laser systems. Here, we report a novel self-modulation method for enhancing laser-induced energy modulation, thereby significantly reducing the requirement of an external laser system. Driven by this scheme, we experimentally realize high harmonic generation in a seeded FEL using an unprecedentedly small external laser-induced energy modulation. An electron beam with a laser-induced energy modulation as small as 1.8 times the slice energy spread is used for lasing at the seventh harmonic of a 266-nm seed laser in a single-stage high-gain harmonic generation (HGHG) setup and the 30th harmonic of the seed laser in a two-stage HGHG setup. The results mark a major step toward a high-repetition-rate, fully coherent x-ray FEL.

Preparation of superhydrophobic nylon-56/cotton-interwoven fabric with dopamine-assisted use of thiol-ene click chemistry.

With the help of dopamine, we constructed a hydroxyl-rich secondary reaction platform on a surface formed by interwoven nylon 56 and cotton fibres. Octadecyl mercaptan and vinyl trimethoxysilane (VTMS) are used for the click coupling preparation of superhydrophobic reagents, which are grafted onto polydopamine aggregates and successfully used to prepare superhydrophobic nylon 56/cotton-interwoven fabric. The static contact angle was 161° and the sliding angle was 8°. Note that the prepared superhydrophobic fabric can withstand corrosive liquids, water washing, ultraviolet radiation and mechanical abrasion, it has excellent superhydrophobic stability, and self-cleaning and oil-water-separation functionalities. This simple, fast and environmentally friendly method can be applied to other substrates and shows tremendous potential for expanding the field of superhydrophobic applications.

On the Performance of a Capacitively Coupled Electrical Impedance Tomography Sensor with Different Configurations.

Capacitively coupled electrical impedance tomography (CCEIT) is a new kind of electrical resistance tomography (ERT) which realizes contactless measurement by capacitive coupling and extends traditional resistance measurement to total impedance measurement. This work investigates the performance of a CCEIT sensor with three different configurations, including the unshielded configuration, the shielded configuration A (the CCEIT sensor with the external shield) and the shielded configuration B (the CCEIT sensor with both the external shield and the radial screens). The equivalent circuit models of the measurement electrode pair of the CCEIT sensor with different configurations were developed. Additionally, three CCEIT prototypes corresponding to the three configurations were developed. Both the simulation work and experiments were carried out to compare various aspects of the three CCEIT prototypes, including the sensitivity distribution, the impedance measurement and the practical imaging performance. Simulation results show that shielded configurations improve the overall average sensitivity of the sensitivity distributions. Shielded configuration A contributes to improve the uniformity of the sensitivity distributions, while shielded configuration B reduces the uniformity in most cases. Experimental results show that the shielded configurations have no significant influence on the imaging quality of the real part of impedance measurement, but do make sense in improving the imaging performance of the imaginary part and the amplitude of impedance measurement. However, configuration B (with radial screens) has no significant advantage over configuration A (without radial screens). This work provides an insight into how shielding measures influence the performance of the CCEIT sensor, in addition to playing an important role in shielding unwanted noise and disturbances. The research results can provide a useful reference for further development of CCEIT sensors.