Chemomechanical Origins of the Dynamic Evolution of Isolated Li Filaments in Inorganic Solid-State Electrolytes.

The penetrating growth of Li into the inorganic solid-state electrolyte (SSE) is one key factor limiting its practical application. Research to understand the underlying mechanism of Li penetration has been ongoing for years and is continuing. Here, we report an in situ scanning electron microscopy methodology to investigate the dynamic behaviors of isolated Li filaments in the garnet SSE under practical cycling conditions. We find that the filaments tend to grow in the SSE, while surprisingly, those filaments can self-dissolve with a decrease in the current density without a reversal of the current direction. We further build a coupled electro-chemo-mechanical model to assess the interplay between electrochemistry and mechanics during the dynamic evolution of filaments. We reveal that filament growth is strongly regulated by the competition between the electrochemical driving force and mechanical resistive force. The numerical results provide rational guidance for the design of solid-state batteries with excellent properties.

N-Doped Carbon Modified (NixFe1-x)Se Supported on Vertical Graphene toward Efficient and Stable OER Performance.

NiFe-based nanomaterials are extensively studied as one of the promising candidates for the oxygen evolution reaction (OER). However, their practical application is still largely impeded by the unsatisfied activity and poor durability caused by the severe leaching of active species. Herein, a rapid and facile combustion method is developed to synthesize the vertical graphene (VG) supported N-doped carbon modified (NixFe1-x)Se composites (NC@(NixFe1-x)Se/VG). The interconnected heterostructure of obtained materials plays a vital role in boosting the catalytic performance, offering rich active sites and convenient pathways for rapid electron and ion transport. The incorporation of Se into NiFe facilitates the formation of active species via in situ surface reconstruction. According to density functional theory (DFT) calculations, the in situ formation of a Ni0.75Fe0.25Se/Ni0.75Fe0.25OOH layer significantly enhances the catalytic activity of NC@(NixFe1-x)Se/VG. Furthermore, the surface-adsorbed selenoxide species contribute to the stabilization of the catalytic active phase and increase the overall stability. The obtained NC@(NixFe1-x)Se/VG exhibits a low overpotential of 220 mV at 20 mA cm-2 and long-term stability over 300 h. This work offers a novel perspective on the design and fabrication of OER electrocatalysts with high activity and stability.

LINC00894 Regulates Cerebral Ischemia/Reperfusion Injury by Stabilizing EIF5 and Facilitating ATF4-Mediated Induction of FGF21 and ACOD1 Expression.

The non-coding RNA LINC00894 modulates tumor proliferation and drug resistance. However, its role in brain is still unclear. Using RNA-pull down combined with mass spectrometry and RNA binding protein immunoprecipitation, EIF5 was identified to interact with LINC00894. Furthermore, LINC00894 knockdown decreased EIF5 protein expression, whereas LINC00894 overexpression increased EIF5 protein expression in SH-SY5Y and BE(2)-M17 (M17) neuroblastoma cells. Additionally, LINC00894 affected the ubiquitination modification of EIF5. Adeno-associated virus (AAV) mediated LINC00894 overexpression in the brain inhibited the expression of activated Caspase-3, while increased EIF5 protein level in rats and mice subjected to transient middle cerebral artery occlusion reperfusion (MCAO/R). Meanwhile, LINC00894 knockdown increased the number of apoptotic cells and expression of activated Caspase-3, and its overexpression decreased them in the oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro models. Further, LINC00894 was revealed to regulated ATF4 protein expression in condition of OGD/R and normoxia. LINC00894 knockdown also decreased the expression of glutamate-cysteine ligase catalytic subunit (GCLC) and ATF4, downregulated glutathione (GSH), and the ratio of GSH to oxidized GSH (GSH: GSSG) in vitro. By using RNA-seq combined with qRT-PCR and immunoblot, we identified that fibroblast growth factor 21 (FGF21) and aconitate decarboxylase 1 (ACOD1), as the ATF4 target genes were regulated by LINC00894 in the MCAO/R model. Finally, we revealed that ATF4 transcriptionally regulated FGF21 and ACOD1 expression; ectopic overexpression of FGF21 or ACOD1 in LINC00894 knockdown cells decreased activated Caspase-3 expression in the OGD/R model. Our results demonstrated that LINC00894 regulated cerebral ischemia injury by stabilizing EIF5 and facilitating EIF5-ATF4-dependent induction of FGF21 and ACOD1.

Green synthesis of N-rich carbon dot-derived crosslinked covalent organic nanomaterial for multipurpose chromatographic applications.

Carbon dots (CDs) derived crosslinked covalent organic nanomaterials (CONs) possessing high specific surface area and abundant surface functional groups are considered to be potential candidates for multimodal chromatographic separations. Typically, the synthesis of CDs and CONs requires harsh reaction conditions and toxic organic solvents, hence, the pursuit of facile and mild preparation strategies is the goal of researchers. In this work, 3-aminopropyltriethoxysilane and D-glucose were used as nitrogen and carbon sources, respectively, to prepare amino-CDs (AmCDs) by rapid low-temperature polymerization rather than the common high-temperature and high-pressure reaction. Then, surface functionalization of the aminated silica gel was carried out in a deep eutectic solvent by using hydrophilic AmCDs and 1,3,5-triformylbenzene (TFB) as the functional monomers. Consequently, a novel N-rich CDs derived CON surface-functionalized silica gel (AmCDs-CON@SiO2) was obtained under mild reaction conditions. The combination of AmCDs and TFB created an ideal CON based chromatographic stationary phase. The incorporation of TFB not only contributed to the successful construction of a crosslinked CON, but also enhanced the interaction forces. The developed AmCDs-CON@SiO2 has a great potential for versatile applications in liquid chromatography. This study proposes a simple stationary phase preparation strategy by the surface modification of silica gel with CDs-based CON. Moreover, this study verified the application potential of CDs derived CON in chromatographic separation. This not only promotes the development of CDs in the field of liquid chromatographic stationary phase, but also provides some reference value for the wide application of cross-linked CON.

Rigidity-Dependent Emission: Inspired Selection of an ATP-Specific Polyvalent Hydrogen Binding-Lighted Fluorophore for Intracellular Amplified Imaging.

ATP, a small molecule with high intracellular concentration (mM level), provides a fuel to power signal amplification, which is meaningful for biosensing. However, traditional ATP-powered amplification is based on ATP/aptamer recognition, which is susceptible to the complex biological microenvironment (e.g., nuclease). In this work, we communicate a signaling manner termed as ATP-specific polyvalent hydrogen binding (APHB), which is mimetic to ATP/aptamer binding but can avoid interference from biomolecules. The key in APHB is a functional fluorophore that can selectively bind with ATP via polyvalent hydrogen, and the fluorescence was lighted with the changes of the molecular structure from flexibility to rigidity. By designing, synthesizing, and screening a series of compounds, we successfully obtained an ATP-specific binding-lighted fluorophore (ABF). Experimental verification and a complex analogue demonstrated that two melamine brackets in the ABF dominate the polyvalent hydrogen binding between the ABF and ATP. Then, to achieve amplification biosensing, fibroblast activation protein (FAP) in activated hepatic stellate cells was taken as a model target, and a nanobeacon consisting of an ABF, a quencher, and an FAP-activated polymer shell was constructed. Benefiting from the ATP-powered amplification, the FAP was sensitively detected and imaged, and the potential relationship between differentiation of hepatocytes and FAP concentration was first revealed, highlighting the great potential of APHB-mediated signaling for intracellular sensing.

Routine Workflow of Spatial Proteomics on Micro-formalin-Fixed Paraffin-Embedded Tissues.

In the era of single-cell biology, spatial proteomics has emerged as an important frontier. However, it still faces several challenges in technology. Formalin-fixed paraffin-embedded (FFPE) tissues are an important material in spatial proteomics, in which fixed tissues are excised using laser capture microdissection (LCM), followed by protein identification with mass spectrometry. For a satisfied spatial proteomics upon FFPE tissues, the excision area is expected to be as small as possible, and the identified proteins are countered upon as much as possible. For a general laboratory for spatial proteomics, a routine workflow is required, not relying on any special device, and is easily operating. In view of these challenges in technology, we initiated a technology evaluation throughout the entire procedure of proteomic analysis with micro-FFPE tissues. In contrast to the protocols reported previously, several innovations in technology were proposed and conducted, such as removal of destaining, decross-linking with "hang-down", solution simplification for peptide generation and balancing to excision area, and capture rate of micro-FFPE tissues. After optimization of all the necessary steps, a routine workflow was established, in which the minimized area for protein identification was 0.002 mm2, while the excision area for a consistent proteomic analysis was 0.05 mm2. Using the developed workflow and collecting the micro-FFPE tissues continuously, for the first time, a spatial proteomic atlas of mouse brain was preliminarily constructed, which exhibited the typical characteristics of spatial-dependent protein abundance and functional enrichment.

Synthesis and Micellization of Carbosilane Sulfonate Surfactants with Short Alkyl Chains.

Carbosilane surfactants, consisting of carbosilane as a hydrophobic group linked to hydrophilic groups, are one kind of silicone surfactants. In this paper, a series of carbosilane sulfonate surfactants with short alkyl chains (Cn-Si2C-SO3Na (n = 1-6)), Me-Si2C-SO3Na, Et-Si2C-SO3Na, Pr-Si2C-SO3Na, Bu-Si2C-SO3Na, Pen-Si2C-SO3Na, and Hex-Si2C-SO3Na, were prepared and characterized by 29 Si NMR, 1H NMR, and FT-IR spectroscopies. The influence of the alkyl chain length on their micellization was studied using surface tension, dynamic light scattering, conductivity, and transmission electron microscopy. The CMC value decreases with increasing length of the short alkyl group. The γCMC value of Cn-Si2C-SO3Na (n = 1-6) increases as the alkyl chain increases from methyl to propyl, while the γCMC value gradually decreases as the alkyl chain increases from propyl to hexyl. The larger and rigid tetramethyldicarbosilane group functioned synergistically with a short alkyl chain, resulting in carbosilane sulfonate surfactants adsorbing at the air/water interface with a rugby ball shape; accordingly, the Amin values of the investigated carbosilane sulfonate surfactants increase with increasing length of the alkyl chain. The micellization process of carbosilane sulfonate surfactants is enthalpy-driven at lower temperatures and entropy-driven at high temperatures. The ΔHm0 values became more negative and ΔSm0 values more positive as the alkyl chain length increased. Aggregates in the range of 10-800 nm were observed for Cn-Si2C-SO3Na (n = 1-6) in an aqueous solution, and the hydrodynamic diameter (Dh) decreased with increasing length of the short alkyl group.

Facile synthesis of a novel polymer/covalent organic framework@silica composite material in deep eutectic solvent for mixed-mode liquid chromatographic separation.

The solvothermal synthesis of covalent organic framework (COF) modified silica gel usually requires the use of harmful organic solvents, tedious steps, and harsh reaction conditions. In pursuit of green chemistry, a new strategy for the facile preparation of COF@SiO2 composite material was realized in this work by using a low-toxicity and low-cost deep eutectic solvent as the reaction medium. Additionally, a flexible polyacrylic acid (PAA) was introduced for the purpose of improving the hydrophilic selectivity and separation efficiency of COF@SiO2. Based on the above ideas, a novel PAA/COF@SiO2 composite was successfully developed as a liquid chromatographic packing material. Performance evaluation of the slurry-packed PAA/COF@SiO2 column showed that diverse types of analytes were effectively separated, and the retention behavior of polar nucleosides showed a U-shaped trend, indicating mixed-mode of hydrophobic/hydrophilic retention mechanisms. Thermodynamic studies revealed that the separation mechanism was largely independent of temperature. This work verifies the feasibility of synthesizing polymer/COF@SiO2 composite material in the deep eutectic solvent. This strategy provides a theoretical reference for the green and facile preparation of COF@SiO2 as an efficient liquid chromatographic stationary phase.

Conformations of Steroid Hormones: Infrared and Vibrational Circular Dichroism Spectroscopy.

Steroid hormone molecules may exhibit very different functionalities based on the associated functional groups and their 3D arrangements in space, i.e., absolute configurations and conformations. Infrared (IR) and vibrational circular dichroism (VCD) spectra of four different steroid hormones, namely dehydroepiandrosterone (DHEA), 17α-methyltestosterone (MTTT), (16α,17)-epoxyprogesterone (Epoxy-P4), and dehydroepiandrosterone acetate (AcO-DHEA), were measured in deuterated dimethyl sulfoxide and some also in carbon tetrachloride. Extensive conformational searches were carried out using the recent developed conformer-rotamer ensemble sampling tool (CREST) which also accounts for solvent effects using an implicit solvation model. All the CREST conformational candidates were then reoptimized at the B3LYP-D3BJ/def2-TZVPD with the PCM of solvent. The good agreements between the experimental IR and VCD spectra and the theoretical simulations provide a conclusive information about their conformational distribution and absolute configurations. The experimental and theoretical IR and VCD spectra of AcO-DHEA in the carbonyl and alkene stretching region showed some discrepancies, and the possible causes related to solvent effects, large amplitude motions and levels of theory used in the modelling were explored in detail. As part of the investigation, additional calculations at the B3LYP-D3BJ/6-31++G (2d,p) and B3LYP-D3BJ/cc-pVTZ levels, as well as some 'mixed' calculations with the double-hybrid functional B2PLYP-D3 were also carried out. The results indicate that the double-hybrid functional is important for predicting the correct IR band pattern in the carbonyl and alkene stretching region.

[Banded chromosome images recognition based on dense convolutional network with segmental recalibration].

Human chromosomes karyotyping is an important means to diagnose genetic diseases. Chromosome image type recognition is a key step in the karyotyping process. Accurate and efficient identification is of great significance for automatic chromosome karyotyping. In this paper, we propose a model named segmentally recalibrated dense convolutional network (SR-DenseNet). In each stage of the model, the dense connected network layers is used to extract the features of different abstract levels of chromosomes automatically, and then the concatenation of all the layers which extract different local features is recalibrated with squeeze-and-excitation (SE) block. SE blocks explicitly construct learnable structures for importance of the features. Then a model fusion method is proposed and an expert group of chromosome recognition models is constructed. On the public available Copenhagen chromosome recognition dataset (G-bands) the proposed model achieves error rate of only 1.60%, and with model fusion the error further drops to 0.99%. On the Padova chromosome dataset (Q-bands) the model gets the corresponding error rate of 6.67%, and with model fusion the error further drops to 5.98%. The experimental results show that the method proposed in this paper is effective and has the potential to realize the automation of chromosome type recognition.

IR and Vibrational Circular Dichroism Spectroscopy of Matrine- and Artemisinin-Type Herbal Products: Stereochemical Characterization and Solvent Effects.

Five Chinese herbal medicines--matrine, oxymatrine, sophoridine, artemisinin, and dihydroartemisinin--were investigated using vibrational circular dichroism (VCD) experiments and density functional theory calculations to extract their stereochemical information. The three matrine-type alkaloids are available from the dry roots of Sophora flavescens and have long been used in various traditional Chinese herbal medicines to combat diseases such as cancer and cardiac arrhythmia. Artemisinin and the related dihydroartemisinin, discovered in 1979 by Professor Youyou Tu, a 2015 Nobel laureate in medicine, are effective drugs for the treatment of malaria. The VCD measurements were carried out in CDCl3 and DMSO-d6, two solvents with different dielectric constants and hydrogen-bonding characteristics. A "clusters-in-a-liquid" approach was used to model both explicit and implicit solvent effects. The studies show that effectively accounting for solvent effects is critical to using IR and VCD spectroscopy to provide unique spectroscopic features to differentiate the potential stereoisomers of these Chinese herbal medicines.

[Modeling of thermal degradation of linarin during concentration process].

Ganmaoling granule, with annual sale of over one billion yuan, is the first brand of domestic cold medicine sales. As the only traditonal Chinese medicine（TCM） quality control indicator of Ganmaoling granule, linarin is thermally unstable. Its content will be changed significantly during the production process, which would then affect the quality of the finished product. In this paper, the law of degradation of linarin was investigated. The experimental results showed that degradation reaction of linarin belongs to the first reaction characteristics. The effective methods to reduce the loss of linarin would be realized fortunately by strictly controlling the heating temperature or shortening the heating time.

[Study on balance of process of alcohol precipitation of ganmaoling granules].

Ganmaoling granule is the first brand of domestic cold medicine sales, but its preparation method and process control parameters are relatively rough. Therefore it is urgent to upgrade the technologies of large varieties of traditional Chinese medicine (TCM). This paper focused on the balance between the remove of impurity and the retention of linarin during the process of alcohol precipitation of Ganmaoling granules. The effects of four factors on the process were investigated via single factor experiments. The results showed that the precipitating period, the initial ethanol concentration and the final ethanol concentration had a great effect on retention of linarin while the initial density of the extract has not. Similarly, the initial ethanol concentration, the final ethanol concentration and the initial extract density have a great effect on the yield of dry extract while the time of alcohol precipitation has not. The parameters of alcohol precipitation of Ganmaoling granules were optimized as 16 h of precipitating period, 95% ethanol as the initial reagent, 70% of the final ethanol concentration, and 1.10 of the initial extract density.

[On-line monitoring of extraction of coldrine by near-infrared spectrum].

Extraction of the four Chinese herbals is the beginning step of the production process of coldrine granules and influences on drug quality significantly. In this paper, the on-line near infrared spectrum was collected during the extraction process of coldrine and then pre-processed by the first derivative. Partial least square regression (PLSR) model was developed for the quantity indicators of linarin, chlorogenic acid and solid content, according to results of both HPLC and weight-loss as reference methods. The correlation coefficient, root mean square error of cross-validation (RMSECV), root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) were used to optimize model parameters and confirm their performance. Correlation coefficients of three quality control indicator models reached more than 0.95.Values of RMSEC of linarin, chloroenic acid and solid content were 0.010 4, 0.009 34 and 0.055 5, respectively. And the values of RMSEP were 0.009 47, 0.142 and 0.008 42, respectively. The models, built on-line analyze data, revealed that the correlation coefficients of predicted values and measured values were greater than 0.97 and values of RSEP of linarin, chloroenic acid and solid content were 8.14%, 8.17% and 9.86%, respectively. The results showed that the NIR method could achieve the on-line detection and real-time monitoring of multi-indexes during the extraction process of coldrine. The technology could be used for drug quality control in the process of practical production, reducing the batch differences and ensuring pharmaceutical quality stability. In addition, it could provide real-time production data for subsequent product quality backtracking.

[Study on main pharmacodynamics and underlying mechanisms of 999 Ganmaoling].

To observe synergistic effects of 999 Ganmaoling (GML) and its Chinese/Western materia medica (CMM and WMM) on pharmacodynamic action and to study underlying mechanisms, their anti-inflammatory, antipyretic effects were compared by assaying the increased capillary permeability induced by glacial acetic acid in mice, ear swelling induced by Xylene in mice, non-specific pleurisy induced by carrageenan in rats, and yeast induced fever in rats. Crystal violet (CV) and microbial activity (XTT) assay were used to evaluate the inhibition of GML and its CMM and WMM on KPN biofilm formation, and scanning electron microscopy (SEM) was applied for observing KPN biofilm morphology changes. The results showed that compared with control group, GML could reduce exudation amount of Evans-Blue and the degree of Ear swelling significantly, and CMM and WMM have no significant effects. The concentration of TNF-α and IL-1ß of rat pleural effusion in GML, CMM and WMM group decreased significantly. The concentration of TNF-α, IL-1ß and IL-8 in GML group, TNF-α, IL-8 in WMM group and IL-8 in CMM in rats serum decreased significantly. The body temperature in rats decreased significantly in GML and WMM group after 4-8 h of administration. CMM group showed no significant difference in rat body temperature compare with control. Compared with control group, GML (55-13.75 g•L⁻¹) could inhibit KPN biofilm formation and reduce number of viable cells in the KPN biofilm. CMM (45-22.5 g•L⁻¹) and WMM (10 g•L⁻¹) could also inhibit KPN biofilm formation and reduce number of viable cells (P<0.01). Result of SEM also showed that GML (55 g•L⁻¹) and its CMM (45 g•L⁻¹) and WMM (10 g•L⁻¹) could interfere the bacterial arrangement of KPN biofilm and extracellular matrix. GML and its CMM & WMM could inhibit the formation of KPN biofilm, CMM & WMM in GML showed synergism and complementation in inhibit KPN biofilm. Results showed that GML had obvious anti-inflammatory and antipyretic effects and could destruct KPN mature biofilm. WMM and CMM showed obvious synergistic effect against inflammation and inhibition of KPN biofilm formation and reduction of number of viable cells but no same effects against fever.

[Study on toxicity of 999 Ganmaoling grain and influence of diet on hepatic toxicity].

This paper was aimed to compare the acute toxicity of 999 Ganmaoling grain and its different ingredients, and investigate the influence of routine diet on the hepatic toxicity induced by Ganmaoling in mice, so as to provide experimental basis for the clinical safety evaluation. Mice were given a single dose of Ganmaoling grain or its different ingredients respectively by gavage, and then observed for 14 days. LD50 values of Ganmaoling grain or its chemical ingredient and the maximal tolerated dose of its herb ingredient were determined. Mice were divided into starvation and diet group, a single dose of Ganmaoling grain was administered by gavage. LD50 values were estimated after 14 day observation. Mice were divided into starvation and diet group. At the same time,control group was set up for each. A single dose of Ganmaoling grain was given. Serum biochemical indexes were detected, liver weight index was calculated and liver tissue morphological change was observed after 6 h. LD50 values were 4.42, 0.64 g•kg⁻¹ for Ganmaoling grain group and chemical ingredient group, respectively. The maximal tolerated dose of the herb ingredient group was close to 24.24 g•kg⁻¹. The toxic symptom was basically similar in the Ganmaoling grain and the chemical ingredient group. The body weight and food intake were decreased to a certain extent in both groups. There were pathological changes of liver and heart tissue in some of the surviving animals. The animals in the Ganmaoling grain group exhibited a lighter toxicity and recovered faster than that in the chemical ingredient group. LD50 values of Ganmaoling grain were 2.56, 6.93 g•kg⁻¹ for starvation and diet group respectively. TD50 values were 1.29, 6.31 g•kg⁻¹ for starvation and diet group respectively. The toxicity of 999 Ganmaoling was less, which may be related to the reduction of toxicity after the combination of herb and chemical ingredients. Compared with starvation group, the values of LD50 and TD50 of diet group was significantly increased, and toxicity was decreased. From the point of view of safety, it is safer to use Ganmaoling in the absence of hunger or after meal. The above tests provide experimental basis for the clinical safety use of Ganmaoling.

Lithiation of SiO2 in Li-ion batteries: in situ transmission electron microscopy experiments and theoretical studies.

Surface passivation has become a routine strategy of design to mitigate the chemomechanical degradation of high-capacity electrodes by regulating the electrochemical process of lithiation and managing the associated deformation dynamics. Oxides are the prevalent materials used for surface coating. Lithiation of SiO2 leads to drastic changes in its electro-chemo-mechanical properties from an electronic insulator and a brittle material in its pure form to a conductor and a material sustainable of large deformation in the lithiated form. We synthesized SiO2-coated SiC nanowires that allow us to focus on the lithiation behavior of the sub-10 nm SiO2 thin coating. We systematically investigate the structural evolution, the electronic conduction and ionic transport properties, and the deformation pattern of lithiated SiO2 through coordinated in situ transmission electron microcopy experiments, first-principles computation, and continuum theories. We observe the stress-mediated reaction that induces inhomogeneous growth of SiO2. The results provide fundamental perspectives on the chemomechanical behaviors of oxides used in the surface coating of Li-ion technologies.

ZIF-8 derived graphene-based nitrogen-doped porous carbon sheets as highly efficient and durable oxygen reduction electrocatalysts.

Nitrogen-doped carbon (NC) materials have been proposed as next-generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich-like zeolitic imidazolate framework (ZIF) derived graphene-based nitrogen-doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open-circuit voltage and power density are obtained in direct methanol fuel cells.

Exploring the potential applications of amphiphilic carbon dots based nanocomposite hydrogel in liquid chromatographic separations.

BACKGROUND: Due to their excellent stability, low toxicity, flexible modification and adjustable functionality, carbon dots (CDs) have a promising application prospect in the field of chromatographic stationary phases. Hydrogels are new functional polymer materials with three-dimensional network structure that have excellent hydrophilicity, high porosity and unique mechanical properties, which are also good candidate materials for liquid chromatography. Nevertheless, a review of the literature reveals that CDs based nanocomposite hydrogels have not yet been reported as HPLC stationary phases. RESULTS: In this work, amphiphilic CDs with multiple functional groups and polyacrylic acid hydrogel were grafted to the surface of silica gel by an in-situ polymerization method, and a CDs/polyacrylic acid nanocomposite hydrogel stationary phase (CDs/hydrogel@SiO2) was prepared. CDs act as the macroscopic cross-linking agents to form a cross-linked network with polyacrylic acid chains through physical cross-linking by hydrogen bonding and chemical cross-linking by amidation and esterification reactions, which not only improve the swelling property of the hydrogel but also increase its stability. Additionally, the introduction of CDs with multifunctional groups modulates the hydrophilic-hydrophobic balance of the hydrogel that also imparts good hydrophobicity to the composite hydrogel. Through the study of retention mechanism and influencing factors, it is certificate that the CDs/hydrogel@SiO2 has mixed-mode chromatographic performance. Furthermore, the CDs/hydrogel@SiO2 column shows great potential for the determination of organic contaminants in environmental water samples. SIGNIFICANCE: This work confirms the potential application of CDs/hydrogel composite for the separation of various samples and provides the possibility of developing CDs based nanocomposite hydrogel in the field of liquid chromatography. Introducing CDs into hydrogel can open up a new way for nanocomposite hydrogels to be used in HPLC, which expands the advance of hydrogel and CDs in separation field.

Design of smart temperature-sensitive terpolymeric hydrogel for multi-applications in liquid chromatography.

Hydrogels with a unique three-dimensional network structure have been widely used in a variety of fields. However, hydrogels are prone to swelling under water-rich conditions, which severely limits their application in liquid chromatography. Therefore, producing a hydrogel with reliable performance and good mechanical property is essential. Smart temperature-sensitive chromatographic packings have attracted extensive attentions in recent years. In this work, sodium 4-styrenesulfonate and 1-octadecene were introduced into the poly(N-isopropylacrylamide) hydrogel to improve mechanical property and separation performance. As a consequence, a smart temperature-sensitive terpolymeric hydrogel modified silica stationary phase (ION-hydrogel@SiO2) was synthesized for multimode liquid chromatographic separation. It was found that this new ION-hydrogel@SiO2 column exhibited excellent chromatographic separation ability for a wide range of analytes. To a certain extent, this new column has a higher chromatographic separation efficiency compared to the commercial C18 column and XAmide column. Moreover, the use of low proportion of organic phase in chromatographic separation is conducive to the realization of green chromatography. By investigating the chromatographic separation mechanism, it has been demonstrated that the hydrogen bonding interaction is primarily responsible for the temperature-sensitive behavior of the hydrogel. Finally, the ION-hydrogel@SiO2 column was used for the determination of pyridoxine in the commercially available tablet samples. In conclusion, this study presents a feasible idea for the development of novel copolymer hydrogels as liquid chromatographic stationary phases.