Yifu Guan

Visuospatial function is a critical aspect of cognitive abilities, encompassing visual perception, attention, memory, and adaptive responses to spatial changes. This paper reviews studies on human visuospatial function, spatial navigation, and factors contributing to visuospatial impairments. After introducing fundamental concepts of visuospatial function and spatial navigation, classical methods for assessing visuospatial performance are summarized. By examining recent advances in spatial navigation studies, this paper discusses factors influencing spatial navigation capabilities and explores how spatial navigation paradigms can be used to investigate visuospatial cognitive impairments. Finally, current limitations in spatial navigation research are highlighted. Overall, the current research has not yet reached definitive conclusions regarding visuospatial aspects. However, this paper aims to enhance the understanding of visuospatial dysfunction and spatial navigation, providing valuable references for future research.

The close relationships of miRNAs with human diseases highlight the urgent needs for miRNA detection. However, the accurate detection of a target miRNA in mixed miRNAs of high sequence homology presents a great challenge. Herein, a novel method called target-protection rolling circle amplification (TP-RCA) is proposed for this purpose. The protective probe is designed so that it can form a fully complementary duplex with the target miRNA and can also mismatch duplexes with other nontarget miRNAs. These duplexes are treated with a single strand-specific nuclease. Consequently, only the target miRNA in a perfect-match duplex can resist the cleavage of nuclease, whereas the nontarget miRNAs in mismatched duplexes will be digested completely. The protected target miRNA can be detected using RCA reactions. MicroRNA let-7 family members (let-7a–let-7f) and nuclease CEL I were used as proof-of-concept models to evaluate the feasibility of the TP-RCA method under different experimental conditions. The experimental results show that the TP-RCA method can unambiguously detect the target let-7 species in mixtures of let-7 family members even though they may differ by only a single nucleotide. This TP-RCA method significantly improves the detection specificity of miRNAs.

Purpose: Paclitaxel resistance in ovarian cancer has become an urgent clinical problem. This study investigated the regulatory effects of RAB17 on the non-coding RNA network of the paclitaxel-resistant ovarian cancer cell A2780/PTX. Methods: Microarray analysis was used to identify differentially expressed genes in paclitaxel-resistant cell A2780/PTX compared to the parent paclitaxel-sensitive cell A2780. Quantitative real-time PCR and Western blot were used to measure the expression of related mRNAs and proteins. The CCK8 assay was used to determine cell survival ratios and drug resistance indices in ovarian cancer cells. The clone forming assay was used to analyze the cell clone proliferation. Flow cytometry was used to analyze the cell cycle. Dual-luciferase reporter gene assays evaluated the relationship between the genes. Results: RAB17 is highly expressed in A2780/PTX cells. RAB17 knockdown increased the cell sensitivity to paclitaxel, inhibited proliferation, and caused cell cycle arrest in the G1 phase in A2780/PTX. Western blot confirmed that RAB17 influenced cell behavior by activating the CDK6/RB signaling pathway. Bioinformatics analyses identified RAB17 as a new target by the microRNA miR-370-3p, and the latter was predicted to interact with circular RNA hsa_circ_0000714. Hsa_circ_0000714 indeed acted as a miRNA sponge for miR-370-3p allowing its regulation of RAB17 expression. This regulation was accomplished through the CDK6/RB signaling pathway. Conclusion: Hsa_circ_0000714 acts as a sponge for miR-370-3p, and regulates RAB17 expression through the CDK6/RB signaling pathway, which plays a role in the malignant progression of the paclitaxel-resistant ovarian cancer cell A2780/PTX.

The central loop of G-quadruplex molecular beacons is a key element to sense target DNA or RNA sequences. In this study, circular dichroism spectroscopy (CD), thermal difference spectrum (TDS), non-denatured non-denaturing gel electrophoresis, and thermal stability analysis were used to investigate the effect of the central loop length on G-quadruplex features. Two series of G-quadruplexes, AG₃TTAG₃-(TTA)n-G₃TTAG₃T (n = 1–8) (named TTA series) and AG₃TTTG₃-(TTA)n-G₃TTTG₃T (n = 1–8) (named TTT series) were examined in K⁺ and Na⁺ solutions, respectively. CD and TDS spectral data indicated that TTA series adopted an antiparallel G-quadruplex structure in Na⁺ solution and a hybrid G-quadruplex structure in K⁺ solution respectively. TTT series exhibited a hybrid G-quadruplex structure in both Na⁺ and K⁺ solutions. UV melting curves indicated that the stability of G-quadruplex in both series was reduced by the elongation of central loop. Thermal stability analysis concluded that the G-quadruplex destabilization with long central loop is an entropy-driven process due to more flexible and longer central loops.

Background: The problem of adulterated meat has become one of the greatest food safety issues in the world. It is reported that the meat used for adulteration includes fox meat, raccoon meat, mink meat, mouse meat, and so on. Although this kind of meat is edible in some areas, such meat is potentially harmful to human health because it is easy to carry bacteria, viruses, and harmful substances. The harm of mouse meat is most frightening. Therefore, it is urgent to develop a fast, accurate, and simple method to effectively identify mouse meat. Methods: In the present study, a new method of isothermal amplification based on the 16S ribosomal RNA gene of the mitochondrial DNA of the mouse was developed. The method is meant to improve the loop-mediated isothermal amplification (LAMP), separating the forward inner primers and backward inner primers, greatly reducing the nonspecific amplification of the method. Results: We have successfully obtained a set of best primers. The developed system allowed for the detection of 0.5% mouse meat from meat mixture effectively and specifically. The best ratio of the primers (F3: F2: F1: R_F) was 1:2:2:8, and the optimum concentration of DNA template was 0.35 ng/μL. Conclusions: The assay has great specificity and sensitivity for detecting mouse meat and could provide specific positive results within 1 h. Highlights: We found a new approach of isothermal amplification to detect mouse source components. The LOD is determined to be 0.5 mg/mg. This new method is easy to perform and is able to provide rapid results in the specific detection of mouse meat sources.

There is a great demand worldwide for bone related implant materials. The drawbacks of chronic infections and poor bone healing of current implant materials have limited their clinical applications. Functionalizing the implant surfaces with antibacterial and osteogenic films on implant materials provides new opportunities for fabricating novel implant materials. In the present study, an ultrathin (GO/Lys)8 film of several ten nanometers, was fabricated using layer-by-layer (LBL) technique with alternative deposition of GO and lysozyme. The deposition of (GO/Lys)n film exhibited a successive growth as supported by ellipsometry, UV-Vis and Fourier transform infrared (FTIR) data, and the physical properties (morphology, roughness and stiffness) of this film were characterized with atomic force microscope (AFM). The ultrathin films exhibited a great effect on bacterium sterilization of Gram-positive S. aureus and Gram-negative E. coli, and enhanced osteogenic differentiation efficiency, showing the potential application on bone implants coatings. We believe that this layer-by-layer assembling strategy will pave the way to fabricating dual functional surfaces and guide the design of implanted surface in the future.

Here we present a novel design of electrochemical signal enhancer to increase the detection sensitivity of electrochemical DNA biosensors. The key element of this enhancer is a lysine‐rich peptide (LRP). Its C‐terminal is conjugated with a planer molecule, being able to intercalate into the base pairs of probe‐target duplexes. The lysine residues of LRP are covalently linked with electrochemical signal indicators, acting as an assembly of electrochemical signal indicators. Experimental results proved the feasibility of the novel design. We have examined the effects of the numbers of lysine residues and the hybridization conditions on the detection sensitivity. The optimization procedures have led to significant sensitivity enhancement, and the LOD (limit of detection) has been determined to be 1.4 amol. This enhancer demonstrates advantages of easy operation, simple instrumentation, and high exemption from environmental influence.

Loop-mediated isothermal amplification (LAMP) has been developed as a versatile method for nucleic acid analysis in many applications. However, non-specific LAMP leading to false-positive outcomes has been observed frequently. To solve this problem, we selected six molecules as the additives for evaluating their effects on the improvement of the LAMP specificity. Experimental results show that bovine serum albumin (BSA) and DL-dithiothreitol (DTT) have negative effects on the LAMP specificity; dimethyl sulfoxide (DMSO), tetramethylene sulfoxide (TMSO), and glycerol could inhibit the non-specific LAMP moderately. Surprisingly, pullulan shows an ability to inhibit the non-specific amplification of LAMP significantly without affecting the sample amplification of LAMP, and this inhibitory effect is concentration dependent. Thus, pullulan could be considered as the most promising additive to improve the amplification specificity in the LAMP-based detection and analysis of nucleic acids.

ERp57 has been identified to be associated with the chemoresistance of human ovarian cancer. However, its biological roles in the chemoresistance phenotype remain unclear. In the present study, the association of ERp57 with paclitaxel-resistant cellular behavior was investigated and the sensitivity enhancement of chemoresistant human ovarian cancer cells to paclitaxel was examined using ERp57-small interfering (si)RNA silencing. Cell viability, cell proliferation, cell apoptosis and cell migration were detected using an MTT assay, clonogenic assay, flow cytometry analysis and transwell assay. Furthermore, mRNA expression levels of ERp57 and protein expression levels of ERp57, STAT3, phosphorylated STAT3, PCNA, nucelolin, TUBB3, P-gp, vimentin, Bcl-2, Bax, Bcl-xl, p53, MMP1, MMP2 and MMP9 of paclitaxel-sensitive human SKOV3 ovarian cancer cells were compared with paclitaxel-resistant counterpart SKOV3/tax using the real-time PCR and western blot analysis. ERp57 was highly expressed in the paclitaxel-resistant SKOV3/tax cells, and experimental results concluded that the paclitaxel-resistance phenotype was due primarily to the activation of the STAT3 signaling pathway. ERp57 overexpression by lentiviral particle infection decreased the sensitivity of SKOV3 cells to paclitaxel. Furthermore, ERp57-siRNA silencing restored paclitaxel sensitivity of SKOV3/tax cells. Notably, the IC50 value of ERp57-siRNA silenced SKOV3/tax cells was reduced to the original level and colony survival was significantly decreased in comparison with that of SKOV3/tax cells. Additionally, co-treatment of ERp57-siRNA silencing and paclitaxel could inhibit the STAT3 signaling pathway and downregulate the expression levels of downstream proteins. Notably, ERp57-siRNA and 100 nM paclitaxel co-treatment downregulated Bcl-2, Bcl-xl, MMP2, MMP9, TUBB3 and P-gp expression levels and upregulated the expression of Bax protein. Furthermore, co-treatment promoted change of the isoform of p53 to p53/p47. Bioinformatics analyses supported the experimental observations that ERp57 was associated with drug resistance in ovarian cancer. The present study implies that ERp57 is a potential therapeutic target for the treatment of paclitaxel-resistant human ovarian cancer.