Mass Transfer Analysis for Achieving High-Rate Lithium-Air Batteries.

Lithium-air batteries (LABs) have aroused worldwide interest due to their high energy density as a promising next-generation battery technology. From a practical standpoint, one of the most pressing issues currently in LABs is their poor rate performance. Accelerating the mass transfer rate within LABs is a crucial aspect for enhancing their rate capability. In this Perspective, we have meticulously analyzed the ion and oxygen transport processes to provide readers with a comprehensive understanding of the mass transfer within LABs. Following this, we have discussed potential misconceptions in the existing literature and propose our recommendations for improving the rate performance of LABs. This Perspective provides a deep insight into the mass transfer process in LABs and offers promising strategies for developing other high-rate metal-O2 batteries.

A Rotating Cathode with Periodical Changes in Electrolyte Layer Thickness for High-Rate Li‒O2 Batteries.

Li-O2 batteries (LOBs) possess the highest theoretical gravimetric energy density among all types of secondary batteries, but they are still far from practical applications. The poor rate performance resulting from the slow mass transfer is one of the primary obstacles in LOBs. To solve this issue, a rotating cathode with periodic changes in the electrolyte layer thickness is designed, decoupling the maximum transfer rate of Li+ and O2. During rotation, the thinner electrolyte layer on the cathode facilitates the O2 transfer, and the thicker electrolyte layer enhances the Li+ transfer. As a result, the rotating cathode enables the LOBs to undergo 58 cycles at 2.5 mA cm-2 and discharge stably even at a high current density of 7.5 mA cm-2. Besides, it also makes the batteries exhibit a large discharge capacity of 6.8 mAh cm-2, and the capacity decay is much slower with increasing current density. Notably, this rotating electrode holds great promise for utilization in other electrochemical cells involving gas-liquid-solid triple-phase interfaces, suggesting a viable approach to enhance the mass transfer in such systems.

Analysis of the value and safety of thyroid-stimulating hormone in the clinical efficacy of patients with thyroid cancer.

BACKGROUND: Thyroid cancer (TC) is a common malignant tumor in the endocrine system. In recent years, the incidence and recurrence rates of TC have been raising due to increasing work pressure and irregular lifestyles. Thyroid-stimulating hormone (TSH) is a specific parameter for thyroid function screening. This study aims to explore the clinical value of TSH in regulating the progression of TC, so as to find a breakthrough for the early diagnosis and treatment of TC. AIM: To explore the value and safety of TSH in the clinical efficacy of patients with TC. METHODS: 75 patients with TC admitted to the Department of Thyroid and Breast Surgery of our hospital from September 2019 to September 2021 were selected as the observation group, and 50 healthy subjects were selected as the control group during the same period. The control group was treated with conventional thyroid replacement therapy, and the observation group was treated with TSH suppression therapy. The soluble interleukin (IL)-2 receptor (sIL-2R), IL-17, IL-35 levels, free triiodothyronine (FT3), free tetraiodothyronine (FT4), CD3+, CD4+, CD8+, CD44V6, and tumor supplied group of factor (TSGF) levels were observed in the two groups. The occurrence of adverse reactions was compared between the two groups. RESULTS: After treatment with different therapies, the levels of FT3, FT4, CD3+, and CD4+ in the observation group and the control group were higher than those before treatment, while the levels of CD8+, CD44V6, and TSGF were lower than those before treatment, and the differences were statistically significant (P < 0.05). More importantly, the levels of sIL-2R and IL-17 in the observation group were lower than those in the control group after 4 wk of treatment, while the levels of IL-35 were higher than those in the control group, and the differences were statistically significant (P < 0.05). The levels of FT3, FT4, CD3 +, and CD4 + in the observation group were higher than those in the control group, and the levels of CD8+, CD44V6, and TSGF were lower than those in the control group. There was no significant difference in the overall incidence rate of adverse reactions between the two groups (P > 0.05). CONCLUSION: TSH suppression therapy can improve the immune function of patients with TC, lower the CD44V6 and TSGF levels, and improve serum FT3 and FT4 levels. It demonstrated excellent clinical efficacy and a good safety profile.

Long Noncoding RNA DLX6-AS1 Regulates the Growth and Aggressiveness of Colorectal Cancer Cells Via Mediating the miR-26a/EZH2 Axis.

Objective: To understand the regulation of long noncoding RNA DLX6-AS1-mediated miR-26a/EZH2 axis in the growth of colorectal cancer (CRC) cells. Methods: The expression of DLX6-AS1, miR-26a, and EZH2 was detected in CRC tissues by quantitative reverse transcription-polymerase chain reaction. The CRC HT-29 cell line was selected for transfection and subjected to observe the growth by MTT and colony formation assays, cell cycle by flow cytometry, and migration and invasion by wound healing and Transwell assays, respectively. Finally, the expression of cycle- and metastasis-related proteins was detected by Western blotting. Results: DLX6-AS1 and EZH2 were increased, with a decreased miR-26a in CRC tissues, showing significant negative correlations between DLX6-AS1 and miR-26a, and between miR-26a and EZH2. CRC patients at advanced stage or with lymphatic metastasis had higher DLX6-AS1 expression. Dual-luciferase reporter gene assay uncovered the targeting correlations between DLX6-AS1 and miR-26a, or miR-26a and EZH2. After transfection of DLX6-AS1 siRNA or EZH2 siRNA, the growth and metastasis of CRC cells were suppressed, arresting the cells in G0/G1 phase, with a magnificent reduction in the ratio of cells in S phase or G2/M phase; meanwhile, Cyclin D1, Vimentin, and MMP9 expressions decreased evidently, whereas E-cadherin expression was upregulated. Changes above were fully reversed after transfection of miR-26a inhibitor, whereas si-EZH2 transfection abolished the positive role of miR-26a inhibitor on growth of CRC cells. Conclusion: Silencing DLX6-AS1 may block the malignant features of CRC cells by inhibiting the expression of EZH2 through upregulation of miR-26a. Thus, it is critical to the development and progression of CRC.

Positive expression of E-cadherin suppresses cell adhesion to fibronectin via reduction of alpha5beta1 integrin in human breast carcinoma cells.

E-cadherin mainly mediated the epithelial cell-cell adhesion, and integrin signaling can modulate the signaling pathway of E-cadherin in the different levels. Up to now, however, it is still unclear that whether E-cadherin could interfere with cell-matrix interaction, a typical adhesion through integrins. In this study we investigated the effects of E-cadherin on cell-matrix adhesion and alpha5beta1 integrin expression in human breast carcinoma cells. It was found that either mRNA or protein level of alpha5 and beta1 subunits of integrin decreased in E-cad-231 compared with Mock-231. Furthermore, the promoter activity of alpha5 gene was inhibited in E-cad-231 compared with Mock-231. Consistently, phosphorylated focal adhesion kinase, a closer key downstream protein kinase of integrin signaling, were also down-regulated in E-cad-231. Furthermore, distribution of beta-catenin was observed and data showed beta-catenin was accumulated in the nucleus in Mock-231, while disappeared from the nucleus and mainly accumulated near the cell surface membrane in E-cad-231. LiCl, a molecule that can inhibit the GSK-3beta activity and down-regulate beta-catenin degradation, could inversely stimulate expression of alpha5 and beta1 integrin. Taken together, these results indicated that positive expression of E-cadherin inhibits the cell adhesion to extracellular matrix mediated by alpha5beta1 integrin signaling.

Role of cell adhesion signal molecules in hepatocellular carcinoma cell apoptosis.

AIM: Cell adhesion molecules and their signal molecules play a very important role in carcinogenesis. The aim of this study is to elucidate the role of these molecules and the signal molecules of integrins and E-cadherins, such as (focal adhesion kinase) FAK, (integrin linked kinase) ILK, and beta-catenin in hepatocellular carcinoma cell apoptosis. METHODS: We first synthesized the small molecular compound, S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and identified it, by element analysis and (1)H NMR. To establish the apoptosis model of the SMMC-7721 hepatocellular carcinoma cell, we treated cells with DCVC in EBSS for different concentrations or for various length times in the presence of 20 micromol/L N,N'-diphenyl-p-phenylenediamine, which blocks necrotic cell death and identified this model by flow cytometry and DNA ladder. Then we studied the changes of FAK, ILK, beta-catenin, and PKB in this apoptotic model by Western blot. RESULTS: We found that the loss or decrease of cell adhesion signal molecules is an important reason in apoptosis of SMMC-7721 hepatocellular carcinoma cell and the apoptosis of SMMC-7721 cell was preceded by the loss or decrease of FAK, ILK, PKB, and beta-catenin or the damage of cell-matrix and cell-cell adhesion. CONCLUSION: Our results suggested that the decrease of adhesion signal molecules, FAK, ILK, PKB, and beta-catenin, could induce hepatocellular carcinoma cell apoptosis.

Down-regulation of PTEN expression due to loss of promoter activity in human hepatocellular carcinoma cell lines.

AIM: To investigate the regulation of phosphatase and tensin homolog deleted on chromosome ten (PTEN) gene expression in human hepatocellular carcinoma (HCC) cell lines. METHODS: The mRNA and protein levels of PTEN were detected by Northern blot and Western blot in HCC cell lines, respectively. Plasmids containing different fragments of PTEN promoter with Luciferase reporter were constructed and transiently transfected into HCC cell lines to study the promoter activity. DNA analysis and RT-PCR were performed to detect the mutation of PTEN promoter and PTEN cDNA. RESULTS: Either protein or mRNA levels of PTEN in L02 cells (as a control) were significantly higher than that in HCC cell lines. The profile of PTEN promoter activity in 8 cell lines was closely correlated with levels of PTEN mRNA and PTEN protein. Furthermore, the sequence analysis of 8 cells lines showed no mutation in the region of PTEN promoter and PTEN cDNA. CONCLUSION: PTEN expression is down-regulated in HCC cell lines probably due to loss of activity of PTEN promoter.

Integrin beta1 subunit overexpressed in the SMMC-7721 cells regulates the promoter activity of p21(CIP1) and enhances its transcription.

Evidence has been emerging to suggest that integrin could induce growth inhibition in some cell types. Some of the molecular mechanisms underlying growth arrest have been elucidated. We reported here that overexpression of integrin beta1 imposed a growth inhibitory effect on the hepatocellular carcinoma cell line SMMC-7721, and this phenomenon was mainly attributed to the cyclin-dependent kinase inhibitor p21(CIP1). Furthermore, our findings suggested that transcription activity of the p21(CIP1) gene could be upregulated in the integrin beta1-overexpressing cells, and possibly controlled by the cis-elements in the core region of the p21(CIP1) promoter.

S-phase delay in human hepatocellular carcinoma cells induced by overexpression of integrin beta1.

AIM: To clarify the mechanisms of integrin overexpression in negatively regulating the cell cycle control of hepatocellular carcinoma cells SMMC-7721. METHODS: The cell cycle pattern was determined by flow cytometry. The mRNA and protein expression levels were assayed by RT-PCR and Western blot, respectively. Stable transfection was performed by Lipofectamine 2000 reagent, and cells were screened by G418. RESULTS: Overexpression of alpha5beta1 or beta1 integrin induced S-phase delay in SMMC-7721 cells, and this delay was possibly due to the accumulation of cyclin-dependent kinase inhibitors (CKIs) p21(cip1) and p27(kip1). The decrease of protein kinase B (PKB) phosphorylation was present in this signaling pathway, but focal adhesion kinase (FAK) was not involved. When phosphorylation of PKB was solely blocked by wortmannin, p27(kip1) protein level was increased. Moreover, S-phase delay was recurred when attachment of the parental SMMC-7721 cells was inhibited by the preparation of poly-HEME, and this cell cycle pattern was similar to that of beta1-7721 or alpha5beta1-7721 cells. CONCLUSION: S-phase delay induced by overexpression of integrin beta1 subunit is attributed to the decrease of PKB phosphorylation and subsequent increases of p21(cip1) and p27(kip1) proteins, and may be involved in the unoccupied alpha5beta1 because of lack of its ligands.

Comparative glycoproteomics based on lectins affinity capture of N-linked glycoproteins from human Chang liver cells and MHCC97-H cells.

We present here an effective technique for the large-scale separation and identification of N-linked glycoproteins from Chang liver cells, the human normal liver cells. To enrich N-linked glycoproteins from the whole cells, a procedure containing the lysis of human liver cells, the solubilization of total proteins, lectin affinity chromatography including Concanavalin A and wheat germ agglutinin was established. Furthermore, captured N-linked glycoproteins were separated by 2-DE, and identified by MS and database searching. Finally, we found 63 N-glycoproteins in Chang liver cells. In addition, using the above method, we identified 7 remarkably up-regulated glycoproteins from MHCC97-H cells, highly metastatic liver cancer cells, compared to Chang liver cells. These up-regulated glycoproteins were associated with liver cancer and might be used as biomarkers for tumor diagnosis. Results showed that we established a high-throughput proteomic analysis for separating N-linked glycoproteins from human liver cells. This strategy greatly improved the glycoprotein analysis method associated with proteome-wide glycosylation changes related to liver cancer. Our work was part of the HUPO Human Liver Proteome Project (HLPP) studies and was supported by CHINA HUPO.

Integrin beta(1A) upregulates p27 protein amount at the post-translational level in human hepatocellular carcinoma cell line SMMC-7721.

Integrins mediate many fundamental cellular processes by binding to components of the extracellular matrix. We showed previously that integrin beta(1A) could inhibit cell proliferation. Integrin beta(1A) stimulated the promoter activity of p21(cip1) and enhanced its transcription in SMMC-7721 cells. In this study, we demonstrated that integrin beta(1A) upregulated p27(kip1) at the post-translational level in SMMC-7721 cells. Our results showed that integrin beta(1A) increased the p27 protein amount, both in cytoplasm and nucleus, but did not affect the p27 mRNA amount. Cycloheximide treatment experiment revealed that the half-life of p27 protein was prolonged in integrin beta1A overexpressing cells, indicating that integrin beta(1A) inhibited the degradation of p27 protein. Our data also provided evidence that both the proteasome and calpain were involved in the degradation of p27 protein in SMMC-7721 cells. Integrin beta(1A) decreased the Skp2 expression and repressed the activity of calpain during G1 phase in SMMC-7721 cells. Taken together, these results indicated that integrin beta(1A) might upregulate the protein amount of p27 through repressing Skp2-dependent proteasome degradation and calpain-mediated proteolysis in SMMC-7721 cells.

Profilin 1 obtained by proteomic analysis in all-trans retinoic acid-treated hepatocarcinoma cell lines is involved in inhibition of cell proliferation and migration.

Previous studies have shown that all-trans retinoic acid (ATRA) suppresses growth of hepatocarcinoma cell in vitro. To understand the underlying mechanisms, we investigated the protein expression profiles by 2-DE in hepatocarcinoma cell line SMMC-7721 treated with ATRA. Our results reveal that six proteins were differently expressed in response to ATRA. Using MS and database searching, they were identified as profilin 1, phosphoglycerate kinase 1, RuvB-like 1, alpha-enolase, pyridoxal kinase and F-actin capping protein. We selected the up-regulated protein, profilin 1 (PFN1), for further studies. The PFN1 expression was increased in response to ATRA in a dose- and time-dependent manner. The PFN1 expression was reduced dramatically in four hepatoma cell lines compared to L02 cell line of non-tumor origin. The PFN1 expression was also examined in 4 cases of primary hepatocarcinoma tissues by Western blot and 30 cases by tissues microarray. It was found that the protein level of PFN1 was lower in hepatocarcinoma tissues compared to that in the adjacent tissues. Similar to ATRA, overexpression of PFN1 led to inhibition of cell proliferation and migration. Furthermore, RNAi-based PFN1 knockdown could rescue the inhibitory effect of ATRA on cell proliferation and migration. In conclusion, ATRA inhibited cell proliferation and migration through up-regulation of PFN1.

Protein phosphatase activity of PTEN inhibited the invasion of glioma cells with epidermal growth factor receptor mutation type III expression.

PTEN is a major tumor suppressor gene that has been shown to inhibit cell invasion. Its mutation has been found in 20-40% of malignant gliomas. Meanwhile, the type III EGFR mutation (EGFRvIII), which was frequently found in gliomas, promoted cell invasion. In the present study, the effects of PTEN on cell invasion were investigated in U87DeltaEGFR glioblastoma cells with EGFRvIII expression but missing PTEN. The cell invasion was downregulated by transfection of phosphatase-active forms of PTEN (wild-type and G129E) but not by PTEN (C124A) with an inactive phosphatase domain; the effects were correlated with decreased tyrosine phosphatase levels of FAK at Tyr397, which was increased by EGFRvIII. Overexpression of FAK mutant (Y397F) could partially mimic the effect of PTEN on cell invasion. Although EGFRvIII increased the levels of P-Akt and PTEN eliminated it, PI-3K inhibitors, wortmannin or Ly294002, could not decrease the cell invasion. In conclusion, PTEN could inhibit cell invasion even in the presence of the constitutively active EGFR; this inhibition depended on its protein phosphatase activity, partially by dephosphorylating FAK, but not depended on its lipid phosphatase activity.

PKB phosphorylation and survivin expression are cooperatively regulated by disruption of microfilament cytoskeleton.

Changes in cell shape can lead to detachment and cell death, and the disruption in the actin cytoskeletal network, as one marker of cell shape changes, can itself induce apoptosis. In this study, the effects of cytochalasin B on the apoptosis-related proteins, protein kinase B and survivin were investigated. Apoptosis induced by disruption of microfilaments with cytochalasin B was found, although it happened at a low level, to simultaneously occur with G2/M arrest in 50% of the cytochalasin B-treated cells. During apoptosis, PKB phosphorylation and survivin expression were decreased by cytochalasin B, and the decline in survivin expression was preceded by PKB dephosphorylation, which implicated that survivin may be a target of PKB protein. The G2/M arrest of cytochalasin B-treated cells may be the direct function of cytochalasin B to microfilaments or the subsequent inhibition of survivin expression, or both. These results suggest that PKB/survivin signaling pathway may be responsible for the apoptosis induced by the disruption of actin cytoskeleton.