Current technologies for removing heavy metal ions are typically metal ion specific. Herein we report the development of a broad-spectrum heavy metal ion trap by incorporation of ethylenediaminetetraacetic acid into a robust metal-organic framework. The capture experiments for a total of 22 heavy metal ions, covering hard, soft, and borderline Lewis metal ions, show that the trap is very effective, with removal efficiencies of >99% for single-component adsorption, multi-component adsorption, or in breakthrough processes. The material can also serve as a host for metal ion loading with arbitrary selections of metal ion amounts/types with a controllable uptake ratio to prepare well-dispersed single or multiple metal catalysts. This is supported by the excellent performance of the prepared Pd2+-loaded composite toward the Suzuki coupling reaction. This work proposes a versatile heavy metal ion trap that may find applications in the fields of separation and catalysis.
Higher hydrocarbons in natural gas must be removed for safe storage, transport, and application of natural gas. Considering C3H8 and CH4 are nonpolar molecules, electrostatic interactions between C3 and MOFs are relatively weak, while they could be sensitive to the van der Waals interactions. Thus, it is an effective method to greatly enhance the separation performance by improving the van der Waals interactions through tuning the pore size of MOFs. Herein, we synthesized a series of isostructural Zr-MOFs with different pore sizes, and the separation performances of these materials for C3/C1 were systematically studied. The results indicate that pore size plays an important role in the C3 storage and C3/C1 separation in MOFs. Specifically, Zr-BPDC with large surface area and pore volume has the highest C3H8 and C3H6 adsorption capacity (159.2 cc/g and 161.5 cc/g at 298 K 1 bar, respectively), while Zr-FUM with the smallest surface area and pore volume has the highest adsorption heat for C3 as well as C3/C1 selectivities (292.0 and 242.2 at 298 K and 1 bar for C3H8/CH4 and C3H6/CH4, respectively) among the five Zr-MOFs. In addition, a defective structure in MOFs can largely improve C3 adsorption capacity for its higher surface area and pore volume, while functional groups in Zr-MOF will not obviously affect the C3 adsorption and C3/C1 separation performance. This work shows that van der Waals interactions in MOFs are predominantly for C3 adsorption and C3/C1 separation, and it can be efficiently tuned by changing the surface area and pore volume in MOFs. More importantly, this information could help design and synthesize a novel adsorbent to separate C3/C1 mixtures.
The pathogenesis of gastric cancer is not completely understood. Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) has recently been identified as a novel negative regulator gene of the immune system, and studies in mice and humans have suggested its inhibitory action in both inflammation and cancer. In this study, we examined the expression levels of TIPE2 in human gastric cancer tissues and also samples of paraneoplastic control tissue, and found that TIPE2 expression was reduced in gastric cancer. To investigate the role of TIPE2 in gastric cell carcinogenesis, a TIPE2 plasmid was introduced into gastric cell lines and TIPE2 function was examined. Colony-forming assays showed that restoration of TIPE2 expression in gastric cells significantly suppressed cell proliferation. Analysis by flow cytometry showed that the number of cells in the S phase of the cell cycle was reduced concomitant with TIPE2 expression, and cell apoptosis was maintained at a low level. Microarray and western blot analyses revealed that TIPE2 selectively up-regulated N-ras and p27 expression. The role of p27 in mediating TIPE2-associated cell growth inhibition was verified by a p27 siRNA interference assay. In this study, we proved that TIPE2 is an inhibitor of gastric cancer cell growth, and suggest that TIPE2 might promote a p27-associated signaling cascade that leads to restored control of the cell cycle and cell division. Our results provide a new molecular mechanism by which TIPE2 may regulate proliferation of gastric cells.
Highly efficient and irreversible capture of radioactive barium from aqueous media remains a serious task for nuclear waste disposal and environmental protection. To address this task, here we propose a concept of barium ion trap based on metal-organic framework (MOF) with a strong barium-chelating group (sulfate and sulfonic acid group) in the pore structures of MOFs. The functionalized MOF-based ion traps can remove >90% of the barium within the first 5 min, and the removal efficiency reaches 99% after equilibrium. Remarkably, the sulfate-group-functionalized ion trap demonstrates a high barium uptake capacity of 131.1 mg g(-1), which surpasses most of the reported sorbents and can selectively capture barium from nuclear wastewater, whereas the sulfonic-acid-group-functionalized ion trap exhibits ultrafast kinetics with a kinetic rate constant k2 of 27.77 g mg(-1) min(-1), which is 1-3 orders of magnitude higher than existing sorbents. Both of the two MOF-based ion traps can capture barium irreversibly. Our work proposes a new strategy to design barium adsorbent materials and provides a new perspective for removing radioactive barium and other radionuclides from nuclear wastewater for environment remediation. Besides, the concrete mechanisms of barium-sorbent interactions are also demonstrated in this contribution.
Background Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children. Methods Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software. Results Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts. Conclusion These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.
Factors secreted by primary tumors can alter the microenvironment at distant organ sites, generating pre-metastatic niches for subsequent metastatic cancer cell colonization. Breast cancer cells have a propensity to home preferentially to the lung, but the underlying molecular mechanisms whereby primary breast carcinoma-derived factors affect the pre-metastatic lung environment before the arrival of the tumor cells are poorly understood. In this study, 4T1 mammary carcinoma cells were subcutaneously injected into the mammary glands of mice, resulting in the induction of inflammation, increased total vessel density and recruitment of bone marrow-derived cells (BMDCs) in pre-metastatic lungs. Subsequent examination revealed that the sites of inflammatory cell clusters in the lungs were tumor metastasis sites. Moreover, vascular endothelial growth factor (VEGF) induced prostaglandin E2 (PGE2) production in mouse pulmonary microvascular endothelial cells (MPVECs) and enhanced the adhesion of 4T1 cells. Treatment with the cyclooxygenase-2 inhibitor celecoxib significantly reduced 4T1 cell adhesion to MPVECs, and also reduced cancer metastasis and the inflammatory response. These results suggest that VEGF may be an underlying carcinoma-derived factor responsible for formation of the pre-metastatic niche in the lung of 4T1 cell-bearing mice. This study, therefore, demonstrated that primary tumors can alter the lung microenvironment during the pre-metastatic phase by triggering an inflammatory response and PGE2 production. Primary tumor-derived VEGF might thus be a crucial factor responsible for the formation of the pre-metastatic niche by inducing PGE2 production.
The size of a smart molecular gate can be continuously tuned from 3.6 to 5.2 Å for gas separation.
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