Removal of Cr(VI) by glutaraldehyde-crosslinked chitosan encapsulating microscale zero-valent iron: Synthesis, mechanism, and longevity.

Microscale zero-valent iron (mZVI) has shown great potential for groundwater Cr(VI) remediation. However, low Cr(VI) removal capacity caused by passivation restricted the wide use of mZVI. We prepared mZVI/GCS by encapsulating mZVI in a porous glutaraldehyde-crosslinked chitosan matrix, and the formation of the passivation layer was alleviated by reducing the contact between zero-valent iron particles. The average pore diameter of mZVI/GCS was 8.775 nm, which confirmed the mesoporous characteristic of this material. Results of batch experiments demonstrated that mZVI/GCS exhibited high Cr(VI) removal efficiency in a wide range of pH (2-10) and temperature (5-35°C). Common groundwater coexisting ions slightly affected mZVI/GCS. The material showed great reusability, and the average Cr(VI) removal efficiency was 90.41% during eight cycles. In this study, we also conducted kinetics and isotherms analysis. Pseudo-second-order model was the most matched kinetics model. The Cr(VI) adsorption process was fitted by both Langmuir and Freundlich isotherms models, and the maximum Langmuir adsorption capacity of mZVI/GCS reached 243.63 mg/g, which is higher than the adsorption capacities of materials reported in most of the previous studies. Notably, the column capacity for Cr(VI) removal of a mZVI/GCS-packed column was 6.4 times higher than that of a mZVI-packed column in a 50-day experiment. Therefore, mZVI/GCS with a porous structure effectively relieved passivation problems of mZVI and showed practical application prospects as groundwater Cr(VI) remediation material with practical application prospects.

[Changes in the proportion of lymphocyte subsets and the expression of surface receptors in peripheral blood of patients with colorectal cancer].

Objective To identify the sets of lymphocytes that could systematically evaluate immune function of colorectal cancer patients, based on the expression of colorectal cancer T cells, natural killer (NK) cells, and NKT cell surface protein receptors. Methods Peripheral blood samples from 144 patients with colorectal cancer and 87 healthy controls were collected, and the differences in surface receptors of lymphocyte subsets in peripheral blood of patients and healthy controls were analyzed by means of flow cytometry and cell culture. Results Compared with healthy control group, the percentage of peripheral blood total lymphocytes, CD16brightCD56dimNK cells and NKT cells decreased in patients with colorectal cancer. The percentage of T cells, CD16brightCD56dimNK cells and NKT cell surface inhibitory receptors T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitor motif domains (TIGIT) increased; T cells, NK cells, NKT cell surface chemokine receptor C-C motif chemokine receptor 7 (CCR7) slightly decreased. Conclusion There are differences in the proportion of NK cell subsets and the expression profile of surface receptors in peripheral blood of patients with colorectal cancer.

The missing nitrogen pieces: A critical review on the distribution, transformation, and budget of nitrogen in the vadose zone-groundwater system.

Intensive agriculture and urbanization have led to the excessive and repeated input of nitrogen (N) into soil and further increased the amount of nitrate (NO3-) leaching into groundwater, which has become an environmental problem of widespread concern. This review critically examines both the recent advances and remaining knowledge gaps with respect to the N cycle in the vadose zone-groundwater system. The key aspects regarding the N distribution, transformation, and budget in this system are summarized. Three major missing N pieces (N in dissolved organic form, N in the deep vadose zone, and N in the nonagricultural system), which are crucial for closing the N cycle yet has been previously assumed to be insignificant, are put forward and discussed. More work is anticipated to obtain accurate information on the chemical composition, transformation mechanism, and leaching flux of these missing N pieces in the vadose zone-groundwater system. These are essential to support the assessment of global N stocks and management of N contamination risks.

Bioremediation of Hg-contaminated soil by combining a novel Hg-volatilizing Lecythophora sp. fungus, DC-F1, with biochar: Performance and the response of soil fungal community.

Reducing Hg contamination in soil using eco-friendly approaches has attracted increasing attention in recent years. In this study, a novel multi-metal-resistant Hg-volatilizing fungus belonging to Lecythophora sp., DC-F1, was isolated from multi-metal-polluted mining-area soil, and its performance in reducing Hg bioavailability in soil when used in combination with biochar was investigated. The isolate displayed a minimum inhibitory concentration of 84.5mg·L-1 for Hg(II) and volatilized >86% of Hg(II) from LB liquid medium with an initial concentration of 7.0mg·L-1 within 16h. Hg(II) contents in soils and grown lettuce shoots decreased by 13.3-26.1% and 49.5-67.7%, respectively, with DC-F1 and/or biochar addition compared with a control over 56days of incubation. Moreover, treatment with both bioagents achieved the lowest Hg content in lettuce shoots. Hg presence and DC-F1 addition significantly decreased the number of fungal ITS gene copies in soils. High-throughput sequencing showed that the soil fungal community compositions were more largely influenced by DC-F1 addition than by biochar addition, with the proportion of Mortierella increasing and those of Penicillium and Thielavia decreasing with DC-F1 addition. Developing the coupling of Lecythophora sp. DC-F1 with biochar into a feasible approach for the recovery of Hg-contaminated soils is promising.

Abnormal expression of circulating and tumor-infiltrating carcinoembryonic antigen-related cell adhesion molecule 1 in patients with glioma.

Glioma, the most prevalent primary tumor of the central nervous system, is known to evade immune surveillance and escape immune attacks by inducing immunosuppression. The homophilic interactions of the carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) serve a critical function in immunoregulation. In the present study, the expression levels of CEACAM1 in peripheral blood mononuclear cells and tumor-infiltrating lymphocytes (TILs) from patients with gliomas were assessed. Furthermore, associations between CEACAM1 expression and multiple clinicopathological characteristics in patients with gliomas were analyzed. The results of the present study suggested that the expression of CEACAM1 in circulating T cells was markedly increased in patients with gliomas compared with control subjects, and was further increased in TILs. Patients with high-grade gliomas [World Health Organization (WHO) grade III-IV] demonstrated a significantly increased expression of CEACAM1 on T cells compared with those with low-grade gliomas (WHO grade I-II). Furthermore, the expression of CEACAM1 on T cells was negatively correlated with the Karnofsky score and the plasma level of interferon-γ in patients with gliomas. Immunohistochemical analysis revealed that the expression levels of CEACAM1 in high-grade glioma tissues (WHO grade III-IV) were increased compared with the expression levels in the controls, and were associated with the expression of CEACAM1 in TILs. In summary, the results of the present study indicate that homophilic interactions of CEACAM1 may participate in the progression and development of gliomas through their negative regulatory effects on T cells. Thus, CEACAM1 may be a promising candidate for targeted glioma immunotherapy.

Combined Blockade of T Cell Immunoglobulin and Mucin Domain 3 and Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 Results in Durable Therapeutic Efficacy in Mice with Intracranial Gliomas.

BACKGROUND Glioblastoma multiforme (GBM) evades immune surveillance by inducing immunosuppression via receptor-ligand interactions between immune checkpoint molecules. T cell immunoglobulin and mucin domain 3 (Tim-3) is a key checkpoint receptor responsible for exhaustion and dysfunction of T cells and plays a critical role in immunosuppression. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) has been recently identified as a heterophilic ligand for Tim-3. MATERIAL AND METHODS We established an intracranial GBM model using C57BL/6 mice and GL261 cells, and treated the mice with single or combined monoclonal antibodies (mAbs) against Tim-3/CEACAM1. The CD4+, CD8+, and regulatory T cells in brain-infiltrating lymphocytes were analyzed using flow cytometry, and the effector function of T cells was assessed using ELISA. We performed a rechallenge by subcutaneous injection of GL261 cells in the "cured" (>90 days post-orthotopic tumor implantation) and naïve mice. RESULTS The mean survival time in the control, anti-Tim-3, anti-CEACAM1, and combined treatment groups was 29.8, 43.4, 42.3, and 86.0 days, respectively, with 80% of the mice in the combined group becoming long-term survivors showing immune memory against glioma cells. Infiltrating CD4+ and CD8+ T cells increased and immunosuppressive Tregs decreased with the combined therapy, which resulted in a markedly elevated ratio of CD4+ and CD8+ cells to Tregs. Additionally, plasma IFN-γ and TGF-ß levels were upregulated and downregulated, respectively. CONCLUSIONS Our data indicate that combined blockade of Tim-3 and CEACAM1 generates robust therapeutic efficacy in mice with intracranial tumors, and provides a promising option for GBM immunotherapy.

Helicobacter pylori chaperone-like protein CagT plays an essential role in the translocation of CagA into host cells.

Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.