Precise Structural Analysis of Neutral Glycans Using Aerolysin Mutant T240R Nanopore.

Glycans play vital roles in nearly all life processes of multicellular organisms, and understanding these activities is inseparable from elucidating the biological significance of glycans. However, glycan research has lagged behind that of DNA and protein due to the challenges posed by structural heterogeneity and isomerism (i.e., structures with equal molecular weights) the lack of high-efficiency structural analysis techniques. Nanopore technology has emerged as a sensitive single-molecule biosensor, shining a light on glycan analysis. However, a significant number of glycans are small and uncharged, making it challenging to elicit identifiable nanopore signals. Here we introduce a R-binaphthyl tag into glycans, which enhances the cation-π interaction between the derivatized glycan molecules and the nanopore interface, enabling the detection of neutral glycans with an aerolysin nanopore. This approach allows for the distinction of di-, tri-, and tetrasaccharides with monosaccharide resolution and has the potential for group discrimination, the monitoring of enzymatic transglycosylation reactions. Notably, the aerolysin mutant T240R achieves unambiguous identification of six disaccharide isomers, trisaccharide and tetrasaccharide linkage isomers. Molecular docking simulations reveal that multiple noncovalent interactions occur between residues R282, K238, and R240 and the glycans and R-binaphthyl tag, significantly slowing down their translocation across the nanopore. Importantly, we provide a demonstration of the kinetic translocation process of neutral glycan isomers, establishing a solid theoretical foundation for glycan nanopore analysis. The development of our technology could promote the analysis of glycan structural isomers and has the potential for nanopore-based glycan structural determination and sequencing.

m6A reader YTHDF1 promotes cardiac fibrosis by enhancing AXL translation.

Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction (MI) can lead to heart failure. RNA N6-methyladenosine (m6A) methylation has been shown to play a pivotal role in the occurrence and development of many illnesses. In investigating the biological function of the m6A reader YTHDF1 in cardiac fibrosis, adeno-associated virus 9 was used to knock down or overexpress the YTHDF1 gene in mouse hearts, and MI surgery in vivo and transforming growth factor-ß (TGF-ß)-activated cardiac fibroblasts in vitro were performed to establish fibrosis models. Our results demonstrated that silencing YTHDF1 in mouse hearts can significantly restore impaired cardiac function and attenuate myocardial fibrosis, whereas YTHDF1 overexpression could further enhance cardiac dysfunction and aggravate the occurrence of ventricular pathological remodeling and fibrotic development. Mechanistically, zinc finger BED-type containing 6 mediated the transcriptional function of the YTHDF1 gene promoter. YTHDF1 augmented AXL translation and activated the TGF-ß-Smad2/3 signaling pathway, thereby aggravating the occurrence and development of cardiac dysfunction and myocardial fibrosis. Consistently, our data indicated that YTHDF1 was involved in activation, proliferation, and migration to participate in cardiac fibrosis in vitro. Our results revealed that YTHDF1 could serve as a potential therapeutic target for myocardial fibrosis.

Tunable Periodic Nanopillar Array for MAPbI3 Perovskite Photodetectors with Improved Light Absorption.

In the field of optoelectronic applications, the vigorous development of organic-inorganic hybrid perovskite materials, such as methylammonium lead triiodide (MAPbI3), has spurred continuous research on methods to enhance the photodetection performance. Periodic nanoarrays can effectively improve the light absorption of perovskite thin films. However, there are still challenges in fabricating tunable periodic patterned and large-area perovskite nanoarrays. In this study, we present a cost-effective and facile approach utilizing nanosphere lithography and dry etching techniques to create a large-area Si nanopillar array, which is employed for patterning MAPbI3 thin films. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results reveal that the introduction of nanopillar structures did not have a significant adverse effect on the crystallinity of the MAPbI3 thin film. Light absorption tests and optical simulations indicate that the nanopillar array enhances the light intensity within the perovskite films, leading to photodetectors with a responsivity of 11.2 A/W and a detectivity of 7.3 × 1010 Jones at 450 nm in wavelength. Compared with photodetectors without nanostructures, these photodetectors exhibit better visible light absorption. Finally, we demonstrate the application of these photodetector arrays in a prototype image sensor.

Highly Crystalized MAPbX3 Perovskite Triangular Nanowire Arrays for Optoelectronic Applications.

Here, a facile fabrication approach for the high-quality 1D perovskite triangular nanowire (TNW) array synthesis through space-confined effect is reported. A soft stamp containing 1D triangular linear array pattern is used to confine the MAPbX3 solution and to guide the growth of the nanowires along the prescribed direction with good crystallinity. The further constructed photodetectors based on the obtained MAPbI3 TNWs exhibit superior photoresponse properties with a responsivity of (125.2 ± 2.5) A W-1 and detectivity of (2.8 ± 0.8) × 1013 Jones at the wavelength of 650 nm. This excellent performance is attributed to the highly crystalline TNW with optical anisotropy and a small asymptotic height, which reduces the probability of the photon reflection and promotes the carrier transport. More interestingly, the increased surface area of the triangular device can present superior flexibility after a couple of thousands of bending cycles. Furthermore, by fabricating 7 × 7 photodetector arrays, the potential image sensor application is demonstrated. The perovskite nanowire fabrication approach is scalable and compatible with current semiconductor manufacturing, which indicates their great potential in broad applications.

Survival analysis and development of a prognostic nomogram for patients with hepatitis B virus-associated hepatocellular carcinoma.

Background and aims: Hepatitis B virus (HBV) is a common cause of hepatocellular carcinoma (HCC) in China, and this study aimed to identify high-risk factors for overall survival and develop a nomogram prediction model. Methods: In the present retrospective cohort study, patients with HBV-associated HCC diagnosed from January 2009 to December 2018 were enrolled. Their clinical characteristics and time-to-event information were retrieved from electronic medical records. The zero time was the date of HCC diagnosis, and the endpoint was death or liver transplantation. Multivariable COX proportional hazard regression was used to screen independent risk factors for overall survival; then a nomogram model was developed to predict the survival probability of HCC patients. Results: A total of 1723 patients were enrolled, with 82.7 % male and a median age of 54.0 years. During a median follow-up time of 41.3 months, 672 cases (39.0 %) died. Age ≥60 years (HR = 1.209), Male (HR = 1.293), ALB <35 g/L (HR = 1.491), AST ≥80 U/L (HR = 1.818); AFP 20-400 ng/mL (HR = 2.284), AFP ≥400 ng/mL (HR = 2.746); LSM 9-22 kPa (HR = 2.266), LSM ≥22 kPa (HR = 4.326); BCLC stage B/C (HR = 4.079) and BCLC stage D (HR = 16.830) were the independent high-risk factors associated with HCC survival. A prognostic nomogram with a consistency index of 0.842 (95 % CI: 0.827-0.858) was developed. The calibration curve for long-term survival rate fitted well. Conclusions: This study identified independent risk factors affecting the survival of patients with HBV-associated HCC and constructed a predictive nomogram model, which can individually predict the overall survival and has good clinical application value.

Genome-wide identification, characterization, evolution and expression analysis of the DIR gene family in potato (Solanum tuberosum).

The dirigent (DIR) gene is a key player in environmental stress response and has been identified in many multidimensional tube plant species. However, there are few studies on the StDIR gene in potato. In this study, we used genome-wide identification to identify 31 StDIR genes in potato. Among the 12 potato chromosomes, the StDIR gene was distributed on 11 chromosomes, among which the third chromosome did not have a family member, while the tenth chromosome had the most members with 11 members. 22 of the 31 StDIRs had a classical DIR gene structure, with one exon and no intron. The conserved DIR domain accounts for most of the proteins in the 27 StDIRs. The structure of the StDIR gene was analyzed and ten different motifs were detected. The StDIR gene was divided into three groups according to its phylogenetic relationship, and 22 duplicate genes were identified. In addition, four kinds of cis-acting elements were detected in all 31 StDIR promoter regions, most of which were associated with biotic and abiotic stress. The findings demonstrated that the StDIR gene exhibited specific responses to cold stress, salt stress, ABA, and drought stress. This study provides new candidate genes for improving potato's resistance to stress.

YTHDF2 Promotes Cardiac Ferroptosis via Degradation of SLC7A11 in Cardiac Ischemia-Reperfusion Injury.

Aims: Myocardial ischemia-reperfusion (I/R) injury facilitates cardiomyocyte death and endangers human health. N6-methyladenosine (m6A) methylation plays a critical role in cardiovascular diseases. The m6A reader YTHDF2 identifies m6A-modified RNA and promotes target RNA degradation. Hence, we hypothesized that YTHDF2 affects I/R injury by regulating RNA stability. Results: Both messenger RNA (mRNA) and protein levels of YTHDF2 were upregulated in I/R mice and hypoxia-reoxygenation (H/R)-induced cardiomyocytes. Silencing endogenous YTHDF2 abrogated cardiac dysfunction and lowered the infarct size in I/R mice, and the forced expression of YTHDF2 aggravated these adverse pathological processes. Consistently, the protective effect of silencing YTHDF2 occurred in cardiomyocytes exposed to H/R and erastin. Further, RNA-Seq and RNA-binding protein immunoprecipitation (RIP) revealed that YTHDF2 recognized the m6A modification sites of the ferroptosis-related gene solute carrier family 7 member 11 (SLC7A11) mRNA to promote its degradation both in vivo and in vitro. Inhibition of SLC7A11 impaired cardiac function, increased infarct size, and the release of lactate dehydrogenase (LDH) in I/R mice after silencing YTHDF2. The beneficial effects of si-YTHDF2 on H/R injury were reversed by co-transfection with SLC7A11-specific siRNA (si-SLC7A11), which substantially exacerbated ferroptosis and the production of reactive oxygen species. Innovation and Conclusion: The cardioprotective effects of silencing YTHDF2 are accomplished by increasing SLC7A11 stability and expression, reducing ferroptosis, and providing novel potential therapeutic targets for treating ischemic cardiac diseases.

Nanofluidic Device for Detection of Lysine Methylpeptides and Sensing of Lysine Methylation.

Protein methylation is the smallest possible yet vitally important post-translational modification (PTM). This small and chemically inert addition in proteins makes the analysis of methylation more challenging, thus calling for an efficient tool for the sake of recognition and detection. Herein, we present a nanofluidic electric sensing device based on a functionalized nanochannel that was constructed by introducing monotriazole-containing p-sulfonatocalix[4]arene (TSC) into a single asymmetric polymeric nanochannel via click chemistry. The device can selectively detect lysine methylpeptides with subpicomole sensitivity, distinguish between different lysine methylation states, and monitor the lysine methylation process by methyltransferase at the peptide level in real time. The introduced TSC molecule, with its confined asymmetric configuration, presents the remarkable ability to selectively bind to lysine methylpeptides, which, coupled with the release of the complexed Cu ions, allows the device to transform the molecular-level recognition to the discernible change in ionic current of the nanofluidic electric device, thus enabling detection. This work could serve as a stepping stone to the development of a new methyltransferase assay and the chemical that specifically targets lysine methylation in PTM proteomics.

Autoimmunity associates with severity of illness in elderly patients with drug-induced liver injury.

Background: Drug-induced liver injury (DILI) is a potentially serious adverse drug reaction. Due to the lack of definite etiology, specific clinical manifestations, and diagnostic methods, its prediction and diagnosis are challenging. Elderly individuals are deemed to be at high risk for DILI due to abnormal pharmacokinetics, aging tissue repair function, comorbidities, and taking multiple drugs. This study aimed to identify the clinical characteristics and explore the risk factors associated with the severity of illness in elderly patients with DILI. Methods: In the present study, the clinical characteristics at the time of liver biopsy of consecutive patients with biopsy-proven DILI who presented at our hospital from June 2005 to September 2022 were evaluated. Hepatic inflammation and fibrosis were assessed according to the Scheuer scoring system. The presence of autoimmunity was considered if IgG level >1.1 × ULN (1826 mg/dL), or high titer (>1:80) of ANA, or SMA. Results: In total, 441 patients were enrolled, and the median age was 63.3 years (IQR, 61.0-66.0); 122 (27.7%), 195 (44.2%), or 124 (28.1%) were classified as having minor, moderate, or severe hepatic inflammation, respectively; and 188 (42.6%), 210 (47.6%) or 43 (9.8%) patients presented minor, significant fibrosis or cirrhosis, respectively. Female sex (73.5%) and the cholestatic pattern (47.6%) were dominant in elderly DILI patients. Autoimmunity existed in 201 patients (45.6%). Comorbidities were not directly associated with the severity of DILI. PLT (OR: 0.994, 95% CI: 0.991-0.997; p < 0.001), AST (OR: 1.001, 95% CI: 1.000-1.003, p = 0.012), TBIL (OR: 1.006, 95% CI: 1.003-1.010, p < 0.001), and autoimmunity (OR: 1.831, 95% CI: 1.258-2.672, p = 0.002) were associated with the degree of hepatic inflammation. Meanwhile, PLT (OR: 0.990, 95% CI: 0.986-0.993, p < 0.001), TBIL (OR: 1.004, 95% CI: 1.000-1.007, p = 0.028), age (OR: 1.123, 95% CI: 1.067-1.183, p < 0.001), and autoimmunity (OR: 1.760, 95% CI: 1.191-2.608, p = 0.005) were associated with the stage of hepatic fibrosis. Conclusion: This study revealed that the presence of autoimmunity represents a more serious illness state of DILI, deserving more intensive monitoring and progressive treatment.

Identification of tagged glycans with a protein nanopore.

Structural complexity of glycans derived from the diversities in composition, linage, configuration, and branching considerably complicates structural analysis. Nanopore-based single-molecule sensing offers the potential to elucidate glycan structure and even sequence glycan. However, the small molecular size and low charge density of glycans have restricted direct nanopore detection of glycan. Here we show that glycan sensing can be achieved using a wild-type aerolysin nanopore by introducing a facile glycan derivatization strategy. The glycan molecule can induce impressive current blockages when moving through the nanopore after being connected with an aromatic group-containing tag (plus a carrier group for the neutral glycan). The obtained nanopore data permit the identification of glycan regio- and stereoisomers, glycans with variable monosaccharide numbers, and distinct branched glycans, either independently or with the use of machine learning methods. The presented nanopore sensing strategy for glycans paves the way towards nanopore glycan profiling and potentially sequencing.

Oxidative Stress Mediated by N6-Methyladenosine Methylation Contributes to High-Fat Diet Induced Male Reproductive Dysfunction.

OBJECTIVE: To determine the mechanism of oxidative stress mediated by N6-methyladenosine (m6A) methylation contributing to high fat diet-induced reproductive dysfunction. RESULTS: In vivo, compared with those in the Control group, the sperm count and sperm motility decrease significantly; the testosterone, luteinizing hormone levels, hyaluronidase, acrosomal enzyme levels, and total antioxidant capacity decrease significantly; malondialdehyde increases significantly in the DIO and DIO-R groups. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2), superoxide dismutase 1 (SOD1), and NAD(P)H quinone dehydrogenase 1 (NQO1) decreases significantly in the DIO and DIO-R groups; m6A levels in testis tissue in the DIO and DIO-R groups increase; the enrichment of m6A-modified Nrf2 mRNA in testis in the DIO group and DIO-R group increases significantly. Also the m6A regulatory proteins increase significantly in the DIO group and DIO-R group. In vitro, compared to palmitic acid treated cells, the reactive oxygen species (ROS) level significantly decreases in STM2457, S-Adenosylhomocysteine treated cells and YTHDC2, YTHDF2 gene silence cells; however, Nrf2 expression increases in all treated cells. In addition, m6A expression decreases. CONCLUSIONS: Oxidative stress mediates by methylation of m6A may contribute to high fat diet-induced male reproductive dysfunction.

The circular RNA circHelz enhances cardiac fibrosis by facilitating the nuclear translocation of YAP1.

Cardiac fibrosis is a common pathological change in the development of heart disease. Circular RNA (circRNA) has been shown to be related to the occurrence and development of various cardiovascular diseases. This study aimed to evaluate the effects and potential mechanisms of circHelz in cardiac fibrosis. Knockdown of circHelz alleviated cardiac fibrosis and myocardial fibroblast activation induced by myocardial infarction (MI) or angiotensin II (AngII) in vivo and transforming growth factor-ß (TGF-ß) in vitro. Overexpression of circHelz exacerbated cell proliferation and differentiation. Mechanistically, nuclear factor of activated T cells, cytoplasmic 2 (NFATc2) was found to act as a transcriptional activator to upregulate the expression of circHelz. The increased circHelz was demonstrated to bind to Yes-associated protein (YAP) and facilitate its localization in the nucleus to promote cell proliferation and growth. Moreover, silencing YAP1 reversed the detrimental effects caused by circHelz in vitro, as indicated by the observed decreases in cell viability, fibrotic marker expression levels, proliferation and migration. Collectively, the protective effect of circHelz knockdown against cardiac fibrosis injury is accomplished by inhibiting the nuclear translocation of YAP1. Thus, circHelz may be a novel target for the prevention and treatment of cardiovascular disease.

Recent advances in micro-/nanostructure array integrated microfluidic devices for efficient separation of circulating tumor cells.

Circulating tumor cells (CTCs) released from the primary tumor to peripheral blood are promising targets for liquid biopsies. Their biological information is vital for early cancer detection, efficacy assessment, and prognostic monitoring. Despite the tremendous clinical applications of CTCs, development of effective separation techniques are still demanding. Traditional separation methods usually use batch processing for enrichment, which inevitably destroy cell integrity and affect the complete information acquisition. Considering the rarity and heterogeneity of CTCs, it is urgent to develop effective separation methods. Microfluidic chips with precise fluid control at the micron level are promising devices for CTC separation. Their further combination with micro-/nanostructure arrays adds more biomolecule binding sites and exhibit unique fluid barrier effect, which significantly improve the CTC capture efficiency, purity, and sensitivity. This review summarized the recent advances in micro-/nanostructure array integrated microfluidic devices for CTC separation, including microrods, nanowires, and 3D micro-/nanostructures. The mechanisms by which these structures contribute to improved capture efficiency are discussed. Two major categories of separation methods, based on the physical and biological properties of CTCs, are discussed separately. Physical separation includes the design and preparation of micro-/nanostructure arrays, while chemical separation additionally involves the selection and modification of specific capture probes. These emerging technologies are expected to become powerful tools for disease diagnosis in the future.

Improved Stretchable and Sensitive Fe Nanowire-Based Strain Sensor by Optimizing Areal Density of Nanowire Network.

Flexible strain sensors, when considering high sensitivity and a large strain range, have become a key requirement for current robotic applications. However, it is still a thorny issue to take both factors into consideration at the same time. Here, we report a sandwich-structured strain sensor based on Fe nanowires (Fe NWs) that has a high GF (37-53) while taking into account a large strain range (15-57.5%), low hysteresis (2.45%), stability, and low cost with an areal density of Fe NWs of 4.4 mg/cm2. Additionally, the relationship between the contact point of the conductive network, the output resistance, and the areal density of the sensing unit is analyzed. Microscopically, the contact points of the conductive network directly affect the sensor output resistance distribution, thereby affecting the gauge factor (GF) of the sensor. Macroscopically, the areal density and the output resistivity of the strain sensor have the opposite percolation theory, which affects its linearity performance. At the same time, there is a positive correlation between the areal density and the contact point: when the stretching amount is constant, it theoretically shows that the areal density affects the GF. When the areal density reaches this percolation threshold range, the sensing performance is the best. This will lay the foundation for rapid applications in wearable robots.

Recent Progress in Iron-Based Microwave Absorbing Composites: A Review and Prospective.

With the rapid development of communication technology in civil and military fields, the problem of electromagnetic radiation pollution caused by the electromagnetic wave becomes particularly prominent and brings great harm. It is urgent to explore efficient electromagnetic wave absorption materials to solve the problem of electromagnetic radiation pollution. Therefore, various absorbing materials have developed rapidly. Among them, iron (Fe) magnetic absorbent particle material with superior magnetic properties, high Snoek's cut-off frequency, saturation magnetization and Curie temperature, which shows excellent electromagnetic wave loss ability, are kinds of promising absorbing material. However, ferromagnetic particles have the disadvantages of poor impedance matching, easy oxidation, high density, and strong skin effect. In general, the two strategies of morphological structure design and multi-component material composite are utilized to improve the microwave absorption performance of Fe-based magnetic absorbent. Therefore, Fe-based microwave absorbing materials have been widely studied in microwave absorption. In this review, through the summary of the reports on Fe-based electromagnetic absorbing materials in recent years, the research progress of Fe-based absorbing materials is reviewed, and the preparation methods, absorbing properties and absorbing mechanisms of iron-based absorbing materials are discussed in detail from the aspects of different morphologies of Fe and Fe-based composite absorbers. Meanwhile, the future development direction of Fe-based absorbing materials is also prospected, providing a reference for the research and development of efficient electromagnetic wave absorbing materials with strong absorption performance, frequency bandwidth, light weight and thin thickness.

Enrichment of IgG and HRP glycoprotein by dipeptide-based polymeric material.

Separation, purification, and identification of glycoproteins are essential for understanding their vital roles in biological and pathological processes. However, glycoproteins are difficult to be captured due to their low abundance, strong interference from non-glycosylated proteins. Here, we report a promising dipeptide-based saccharide recognition platform to selectively enrich two typical glycoproteins, named immunoglobin G (IgG) and horseradish peroxidase (HRP). Different from the conventional glycoprotein enrichment method based on boronic acid affinity or hydrophilic interaction with glycans, the present method was established based on affinity between Pro-Glu (PE) dipeptide and mannose, which is a key unit in the pentasaccharide core of the IgG and HRP glycans. The prepared PE homopolymer surface was proved to selectively bind IgG and HRP superior to that of bovine serum albumin (BSA). Benefiting from this feature, selective enrichment of IgG and HRP was achieved from a protein mixture containing 200-fold BSA interference by using polyPE@SiO2 under a dispersive solid-phase extraction (dSPE) mode. High adsorption capacity, controllable and selective adsorption behaviors, as well as satisfactory recovery demonstrated the high potential of the dipeptide-based polymeric material in IgG and HRP enrichment. This study might provide a new insight to solve the challenging problem of glycoprotein separation.

[Effects of Biochar Addition on Soil Nitrogen Mineralization and Leaching Characteristics in Riparian Zone of Taihu Lake].

Nitrogen mineralization in riparian soil changes the migration and utilization efficiency of nitrogen, which is closely related to the control of water eutrophication. The differences in soil properties caused by land use alter nitrogen retention and transport capacity. Therefore, the soil of three land use types (woodland, grassland, and cultivated land) in the western riparian zone of Taihu Lake were selected for research on the dynamic changes in nitrogen mineralization amount using an incubation experiment and a leaching characteristics by soil column leaching experiment, and their environmental effects were also studied under different biochar addition conditions (0%, 1%, and 5%). The results showed that, in general, the addition of biochar inhibited nitrogen mineralization in forest land and grassland soil, whereas the effect of biochar on nitrogen mineralization in cultivated land was promoted in low concentrations but inhibited in high concentrations. Leaching experiments showed that the biochar addition reduced the loss of soil mineral nitrogen, and the reduction rate in ammonia nitrogen was 23.28%-39.79%, whereas there was little difference between the three land use types. The nitrate decreased by 17.20%-44.49%, and the reduction rate of cultivated land was smaller than that of forest land and grassland. In conclusion, the input of biochar into grassland and cultivated land can better maintain soil fertility and reduce soil nitrogen loss in riparian soil.

Discerning Tyrosine Phosphorylation from Multiple Phosphorylations Using a Nanofluidic Logic Platform.

Discerning tyrosine phosphorylation (pTyr) catalyzed by Tyr kinase is central to the revelation of oncogenic mechanisms and the development of targeted anticancer drugs. Despite some techniques, this goal remains challenging, especially when faced with the interference of multiple phosphorylation events, including serine (pSer) and threonine phosphorylation (pThr). We describe here a functional polymer-modified artificial ion nanochannel, which enables the sensitive and selective recognition of phosphotyrosine (pY) peptide by the distinct ionic current change. Such a recognition effect allows for the nanochannel to work in a complex protein digest condition. Further, the implementation of nanofluidic logic functions with the addition of Ca2+ dramatically improves the selectivity of the nanochannel to pY peptide and thus can discern pTyr by the Tyr kinase from pSer by the Ser/Thr kinase through simultaneously monitoring multisite phosphorylation at the same or different peptide substrates in one-pot. This logic sensing platform displays the potential in differentiating Tyr kinase and Ser/Thr kinase and assessing multi-kinase activities in multi-targeted drug design.

Biomimetic calcium-inactivated ion/molecular channel.

A phosphopeptide-modified nanochannel was prepared based on a conical polymeric nanopore. It shows a reversible Ca2+-induced inactivation effect toward the ion flow and molecular transport, resulting from Ca2+ binding-caused surface charge neutralization and hydrophilicity reduction, and Ca2+ removal by the competitive binding.