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Herein, we synthesized a novel core-satellite CdTe/Silica/Au NCs hybrid sphere by covalently linking the separately synthesized highly fluorescent bovine serum albumin (BSA) stabilized gold nanoclusters (Au@BSA NCs) to the surface of the amino functionalized CdTe@SiO2 spheres by using the EDC chemistry. Numerous “satellites” of Au NCs were linked on the surface of the CdTe@SiO2 by the way of amide bonding. The synthesized dual-emission hybrid spheres were further characterized by the transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), UV–vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, photoluminescence (PL), etc. Finally, the CdTe/Silica/Au NCs hybrid spheres were developed as ratiometric fluorescence probe for the determination of Cu2+ with high sensitivity and selectivity. The fluorescence intensity ratio (F 545nm/F 655nm) of the probe against the concentration of Cu2+ showed a good linear relationship from 6.0×10−7 molL−1 to 100.0×10−7 molL−1. It showed an excellent reproducibility (0.67% relative standard deviation for 10 replicate measurements of Cu2+ at 40.0×10−7 molL−1) and low detection limit (4.1×10−7 molL−1). Furthermore, the ratiometric fluorescent probe was successfully applied in the determination of Cu2+ in vegetable samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Glycolysis provides tumors with abundant nutrients through glucose (Glu) metabolism. As a therapeutic target, precise targeting and effective inhibition of the glycolysis process remains a major challenge in anti-metabolic therapy. In this study, a novel dual-template molecularly imprinted polymer (D-MIP), capable of specifically recognizing glucose transporter member 1 (GLUT1) and hexokinase-2 (HK2) was prepared for anti-glycolytic tumor therapy. The imprinting factors of D-MIP for the recognition of the template molecules, the GLUT1 epitope and the HK2 epitope, were 2.1 and 2.5, respectively, enabling specific recognition of the entire target protein. Targeting GLUT1 with D-MIP could impede its Glu uptake, while simultaneously inhibiting the activity of cytoplasmic HK2, thereby reducing the metabolic rate of Glu. Cell experiments demonstrated that inhibition of HK2 resulted in downregulation of the downstream, products glucose-6-phosphate (6PG) and lactate (LA). In vitro and in vivo experimental results indicated that D-MIP exhibited significant targeting and inhibitory effects on GLUT1 and HK2, respectively, which suppressed tumor glycolysis and induced apoptosis in MCF-7 cells. Furthermore, mouse tumor models and hematoxylin-eosin (H&E) staining confirmed the excellent anti-tumor efficacy and favorable biocompatibility of D-MIP. This work represents the first design and development of a dual-template imprinted polymer targeting key transport channels and metabolic enzymes involved in glycolysis, advancing the research and application of anti-glycolytic tumor therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Protein phosphorylation is one of the most common and important post-translational modifications that regulates almost all life processes. In particular, protein phosphorylation regulates the development of major diseases such as tumors, neurodegenerative diseases, and diabetes. For example, excessive phosphorylation of Tau protein can cause neurofibrillary tangles, leading to Alzheimer's disease. Therefore, large-scale methods for identifying protein phosphorylation must be developed. Rapid developmentin efficient enrichment methods and biological mass spectrometry technologies have enabled the large-scale identification of low-abundance protein O -phosphorylation modifications in, allowing for a more thorough study of their biological functions. The N -phosphorylation modifications that occur on the side-chain amino groups of histidine, arginine, and lysine have recently received increased attention. For example, the biological function of histidine phosphorylation in prokaryotes has been well studied; this type of modification regulates signal transduction and sugar metabolism. Two mammalian pHis kinases (NME1 and NME2) and three pHis phosphatases (PHPT1, LHPP, and PGAM5) have been successfully identified using various biological methods. N -Phosphorylation is involved in multiple biological processes, and its functions cannot be ignored. However, N -phosphorylation is unstable under acidic and thermal conditions owing to the poor chemical stability of the P-N bond. Unfortunately, the current O -phosphorylation enrichment method, which relies on acidic conditions, is unsuitable for N -phosphorylation enrichment, resulting in a serious lag in the large-scale identification of protein N -phosphorylation. The lack of enrichment methods has also seriously hindered studies on the biological functions of N -phosphorylation. Therefore, the development of efficient enrichment methods that target protein N -phosphorylation is an urgent undertaking. Research on N -phosphorylation proteome enrichment methods is limited, hindering functional research. Thus, summarizing such methods is necessary to promote further functional research. This article introduces the structural characteristics and reported biological functions of protein N -phosphorylation, reviews the protein N -phosphorylation modification enrichment methods developed over the past two decades, and analyzes the advantages and disadvantages of each method. In this study, both antibody-based and nonantibody-dependent methods are described in detail. Owing to the stability of the molecular structure of histidine, the antibody method is currently limited to histidine phosphorylation enrichment research. Future studies will focus on the development of new enrichment ligands. Moreover, research on ligands will promote studies on other nonconventional phosphorylation targets, such as two acyl-phosphates (pAsp, pGlu) and S -phosphate (pCys). In summary, this review provides a detailed analysis of the history and development directions of N -phosphorylation enrichment methods.

Aim: To detect the variations of mitochondrial 12S rRNA in patients with gastric carcinoma, and to study their significance and the relationship between these variations and the genesis of gastric carcinoma., Methods: PCR amplified mitochondrial 12S rRNA of 44 samples including 22 from gastric carcinoma tissues and 22 from adjacent normal tissues, was detected by direct DNA sequencing. Then laser capture microdissection technique (LCM) was used to separate the cancerous cells and dysplasia cells with specific mutations. Denaturing high performance liquid chromatography (DHPLC) plus allele-specific PCR (AS-PCR), nest-PCR and polyacrylamide gel electrophoresis (PAGE) were used to further evaluate this mutant property and quantitative difference of mutant type between cancerous and dysplasia cells. Finally, RNAdraw biosoft was used to analyze the RNA secondary structure of mutant-type 12S rRNA., Results: Compared with Mitomap database, some new variations were found, among which np652 G insertion and np716 T-G transversion were found only in cancerous tissues. There was a statistic difference in the frequency of 12S rRNA variation between intestinal type (12/17, 70.59%) and diffusive type (5/17, 29.41%) of gastric carcinoma (P<0.05). DHPLC analysis showed that 12S rRNA np652 G insertion and np716 T-G transversion were heteroplasmic mutations. The frequency of 12S rRNA variation in cancerous cells was higher than that in dysplasia cells (P<0.01). 12S rRNA np652 G insertion showed obviously negative effects on the stability of 12S rRNA secondary structure, while others such as T-G transversion did not., Conclusion: The mutations of mitochondrial 12S rRNA may be associated with the occurrence of intestinal-type gastric carcinoma. Most variations exist both in gastric carcinomas and in normal tissues, and they might not be the characteristics of tumors. However, np652 G insertion and np716 T-G transversion may possess some molecular significance in gastric carcinogenesis. During the process from normality to dysplasia, then to carcinoma, 12S rRNA tends to convert from homoplasmy (wild type) to heteroplasmy, then to homoplasmy (mutant type, np717 T-G).

Aim: To explore the instabilities, polymorphisms and other variations of mitochondrial D-loop region and downstream gene 12S rRNA-tRNA(phe) in gastric cancers, and to study their relationship with gastric cancer., Methods: Three adjacent regions (D-loop, tRNA(phe) and 12S rRNA) were detected for instabilities, polymorphisms and other variations via PCR amplification followed by direct DNA sequencing in 22 matched gastric cancerous tissues and para-cancerous normal tissues., Results: PolyC or (CA) (n) instabilities were detected in 13/22(59.1 %) gastric cancers and 9/22(40.9 %) in the control (P>0.05). There existed 2/12(16.7 %) and 6/10(60 %) alterations of 12S rRNA-tRNA(phe) in well differentiated gastric cancers and poorly differentiated ones, respectively (P<0.05). Some new variations were found, among which np 318 and np 321 C-T transitions in D-loop region were two of the five bases for H-strand replication primer. np 523 AC-deletion and np 527 C-T transition occurred at mtTF1 binding site (mtTFBS), which were associated with the transcription of downstream mitochondrial genome. Seven samples showed the np 16 182 polyC instabilities, five of which simultaneously showed np 16 189 T-C transitions., Conclusion: There is no statistic significance of instabilities and polymorphisms in mitochondrial D-loop region between gastric cancerous and para-cancerous normal tissues, which suggests that the instability might relate to heredity or be dependent on aging. There is a significant correlation between differentiation degree of gastric cancer and variant frequencies of 12S rRNA-tRNA(phe). The poorly differentiated gastric cancers are more prone to 12S rRNA-tRNA(phe) variations, or gastric cancers with 12S rRNA-tRNA(phe) variations are more likely to be poorly differentiated. np 16 189 T-C transition may be one of the important reasons for polyC instability in gastric cancer.

Monolithic columns of capillary electrochromatography (CEC) with low electroosmotic flow (EOF) have been prepared by in-situ polymerization of butylmethacrylate and ethylene dimethacrylate, without any charged groups existed in the reaction mixture. The good reproducibility of the columns has been proved no matter if they are prepared in the same or different batches. Besides the traditional ternary porogenic mixture of 1-propanol, 1,4-butanediol and water, a binary porogenic mixture with only alcohols has also been adopted. In comparing with the ternary porogenic mixture, the design of binary mixture allows fine control of pore diameter and the formation of specific surface of the monolithic polymers. The effects of composition and ratio of porogenic reagents on EOF of the column systems have also been shown. The pore properties and EOF of monolithic columns with different porogenic mixtures were investigated. The results of scanning-electron micrograph show that the continuous beds were quite different from each other, while the proportions of 1-propanol were the same under these two situations. In addition, the Joule heat effect of such columns has been studied by varying the inner diameter of capillary columns. The effect of length of capillary on the EOF was also studied. Under the conditions of high pH and high concentrations of organic solvents, low EOF was obtained to satisfy different needs from the diversified separation modes. Through the separation of acidic compounds, monolithic columns with low EOF have shown potentialities in the analysis of charged samples.

In capillary electrochromatography with the mixed-mode stationary phase, while the transfer of solutes could be controlled by the contributions of chromatography (reversed-phase and ion exchange), the transfer of charged solutes could be influenced by electrophoresis transfer. According to the principle of ion independent transfer and several kinds of interaction between solute, mobile phase, and stationary phase, an theoretical expression was derived to describe the relationship among the apparent transfer velocity of solute, the transfer velocities in various forms and the diversified interactions. The studies focused on the influence of various parameters (e.g., pH, organic modifier content, stationary phase proportion) and the transfer characters of various solutes in the mixed-mode capillary electroosmotic chromatography (CEC). These results demonstrate that electroosmotic flow in the mixed stationary phase electrochromatography are kept high and steady within wide ranges of pH and organic modifier content. The separation was affected by the pH through the change of the solutes conformation. The influence of neutral solutes by organic modifier complies with the rule of conventional reversed-phase CEC. The separation of charged solutes was influenced evidently by the compete reagents which could improve the shape of the peak, but it was not so important as in the conventional ion exchange chromatography due to the adjustment by the function of electrophoresis.

In high performance liquid chromatography, it is necessary to apply multi-composition gradient elution for the separation of complex samples such as environmental and biological samples. Multivariate stepwise gradient elution is one of the most efficient elution modes, because it combines the high selectivity of multi-composition mobile phase and shorter analysis time of gradient elution. In practical separations, the separation selectivity of samples can be effectively adjusted by using ternary mobile phase. For the optimization of these parameters, the retention equation of samples must be obtained at first. Traditionally, several isocratic experiments are used to get the retention equation of solute. However, it is time consuming especially for the separation of complex samples with a wide range of polarity. A new method for the fast optimization of ternary stepwise gradient elution was proposed based on the migration rule of solute in column. First, the coefficients of retention equation of solute are obtained by running several linear gradient experiments, then the optimal separation conditions are searched according to the hierarchical chromatography response function which acts as the optimization criterion. For each kind of organic modifier, two initial linear gradient experiments are used to obtain the primary coefficients of retention equation of each solute. For ternary mobile phase, only four linear gradient runs are needed to get the coefficients of retention equation. Then the retention times of solutes under arbitrary mobile phase composition can be predicted. The initial optimal mobile phase composition is obtained by resolution mapping for all of the solutes. A hierarchical chromatography response function is used to evaluate the separation efficiencies and search the optimal elution conditions. In subsequent optimization, the migrating distance of solute in the column is considered to decide the mobile phase composition and sustaining time of the latter steps until all the solutes are eluted out. Thus the first stepwise gradient elution conditions are predicted. If the resolution of samples under the predicted optimal separation conditions is satisfactory, the optimization procedure is stopped; otherwise, the coefficients of retention equation are adjusted according to the experimental results under the previously predicted elution conditions. Then the new stepwise gradient elution conditions are predicted repeatedly until satisfactory resolution is obtained. Normally, the satisfactory separation conditions can be found only after six experiments by using the proposed method. In comparison with the traditional optimization method, the time needed to finish the optimization procedure can be greatly reduced. The method has been validated by its application to the separation of several samples such as amino acid derivatives, aromatic amines, in which satisfactory separations were obtained with predicted resolution.

The separation mechanism for neutral solutes on a cyano column in capillary electrochromatography (CEC) was investigated and the effects of components of mobile phases and the kinds of buffers on retention of samples were studied. In comparing the separation behavior of samples on CN column with reversed-phase ODS column and normal phase SI column, the peak order was different on CN column under different experimental conditions, and the characteristics of CN column having both reversed and normal phase mechanisms were obvious. The migration velocities for neutral solutes of different polarity on CN column were very different by the effects of two mechanisms under different operating conditions. It is easy to change peak order and to adjust selectivity.