Adsorption of Chromate from Aqueous Solution by Polyethylenimine Modified Multi-Walled Carbon Nanotubes.

In this paper, multiwall carbon nanotubes (MWCNTs) were modified by Polyethylenimine of different molecular weight of 1800 (MWCNTs-18) and 7000 (MWCNTs-70). The structure and morphology of the functionalized MWCNTs were characterized by thermogravimetric analysis (TGA), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The curve of TGA showed that the mass loss of MWCNTs-18 and MWCNTs-70 were 46.5% and 51.9% respectively, which was remarkably different with pristine MWCNTs. The XRD demonstrated that the structure of the pristine MWCNTs and functionalized MWCNTs were similar. In addition, the experiment of the removal of chromate from water solution using functionalized MWCNTs was also conducted. The experimental conditions such as concentration of chromate, temperature, pH were studied. The maximum uptake capacities for chromate anions were obtained at the concentration of 0.4 mmol·L-1. The solution pH showed a significant effect on chromate removal over a pH range from 4.0 to 9.0. Besides, the uptake capacities for chromate anions on MWCNTs-18 and MWCNTs-70 increased as the temperature increase within the range from 30 to 60 °C. Under the experimental conditions, the maximum uptake capacities of MWCNTs-18 and MWCNTs-70 for chromate anions were 0.27 and 0.33 mmol·g-1 respectively. The thermodynamic parameters of the uptake process were calculated, and the results showed that the process of uptake chromate was spontaneous.

Preparation and tunable luminescent characteristics of SiO2 coated ZnO:LiAc nanoparticles.

ZnO:LiAc nanopaticles were successfully synthesized though a colloidal-sol technique in nonaqueous solution under ultrasonic irradiation. The luminescent characteristics from blue to red can be tunable by varying [Li]/[Zn] ratios. The possible reason of tunable luminescent characteristics can be attributed to the increase of density of oxygen vacancies caused by Li+ adsorbed in the surface of magic-sized ZnO nanocrystals based on XRD, zeta potential and XPS results. What's more, it is found that SiO2 shell coated on ZnO:LiAc nanoparticles can improve the surface property of ZnO nanoparticles and enhance the PL emission intensity and optical stability. Due to its excellent luminescent characteristic and optical stability, as-prepared SiO2 coated ZnO:LiAc nanoparticles may be a promising candidate for some applications in high-efficiency low-voltage phosphor, solar cells and biological luminescent labels.

Fe3+-citric acid/sodium alginate hydrogel: A photo-responsive platform for rapid water purification.

As water pollution in human society becomes more and more serious, the demand for materials that can be used for wastewater treatment is increasing. Here, we reported a sodium alginate-based hydrogel (Fe3+-CA/SA hydrogel) that can efficiently photocatalyze the degradation of malachite green. The Fe3+-CA/SA hydrogel is composed of sodium alginate, citric acid, and Fe3+. The hydrogel has multi-leveled pore structure and photochromic ability. Benefiting from the unique microstructure and positive feedback chemical reaction process, the hydrogel has high photocatalytic efficiency. Under 365 nm UV light irradiation, the hydrogel can degrade around 95% of malachite green (20 mg/L) in about 4 min, and there is no need to add H2O2 in the degradation process. The work helps to expand the application of sodium alginate-based hydrogels in the field of water treatment. It also has exploratory significance for the principle of photocatalytic degradation of malachite green.

Comparative study of esophagectomy, endoscopic therapy, and radiotherapy for cT1N0M0 esophageal cancer in elderly patients: A SEER database analysis.

BACKGROUND: The number of patients diagnosed with early stage disease (T1a or T1b) has been increasing. This study was conducted to investigate the effect of esophagectomy (ES), endoscopic therapy (ET), and radiotherapy (RT) on long-term survival in elderly patients with cT1N0M0 esophageal cancer. METHODS: We searched the Surveillance, Epidemiology, and End Results (SEER) database to identify the records of elderly patients (≥ 75 years) with cT1N0M0 esophageal cancer between 2004 and 2014. Patient demographics and esophageal cancer parameters were compared among ES, ET, and RT groups. The Kaplan-Meier method and Cox proportional hazard modeling were used to compare long-term survival. RESULTS: Data from 954 esophageal cancer patients (ES: n = 196; ET: n = 224; RT: n = 534) were identified. Multivariate Cox regression analysis showed that five-year survival in the ET and ES groups was significantly higher than in the RT group. After propensity score matching, we found no difference in five-year survival between ES and ET. CONCLUSION: Using SEER data, we identified a significant survival advantage with the use of ES and ET compared to RT in patients with cT1N0M0 esophageal cancer aged > 75 years, while the long-term survival of patients after ET and ES was not significantly different.

Practical value of identifying circulating tumor cells to evaluate esophageal squamous cell carcinoma staging and treatment efficacy.

BACKGROUND: This study was conducted to investigate the correlation between clinicopathological features and post-therapeutic response in esophageal squamous cell carcinoma (ESCC) patients. Peripheral blood circulating tumor cells (CTCs) expressing epithelial-mesenchymal transition markers were identified. METHODS: Peripheral blood samples were collected from 71 patients with newly diagnosed ESCC and 40 healthy volunteers. CTCs were isolated using CanPatrol CTC enrichment technology. RNA-fluorescent in situ hybridization was used to phenotype the CTCs on the basis of epithelial and/or mesenchymal markers. RESULTS: The median mesenchymal CTC counts in 71 patients were: 0 in 19 stage I patients, 2 in 31 stage II, and 3 in 21 stage III/IV. The overall diagnostic performance of total CTCs to correctly identify ESCC patients was 0.991. We observed a correlation between increases in tumor size or advanced stage and an increased number of mesenchymal CTCs (P < 0.05). Thirty-nine patients were administered two cycles of neoadjuvant chemotherapy and their therapeutic response was evaluated: 2 complete response, 20 partial response, 13 stable disease, and 4 progressive disease. After treatment, the positive rate of mesenchymal CTCs was 70.6% in the progressive and stable disease group versus 36.4% in the complete and partial response group (P = 0.05). CONCLUSION: The results showed that mesenchymal CTC count is related to ESCC clinical stage and the efficacy of neoadjuvant chemotherapy.

Altered carotid body function by intermittent hypoxia in neonates and adults: relevance to recurrent apneas.

Chronic intermittent hypoxia (CIH) is associated with recurrent apneas in adults and premature infants. It has been proposed that reflexes arising from the carotid bodies contribute to the autonomic abnormalities associated with CIH. The purpose of this review is to summarize recent studies on the effects of CIH on adult and neonatal carotid bodies. CIH exerts two major effects on the adult carotid body that includes sensitization of the hypoxic sensory response and induction of sensory long-term facilitation (LTF). In neonates CIH leads to sensitization of the hypoxic response but does not induce sensory LTF. The effects of CIH on carotid bodies develop over time and could be reversed in adults but not in neonates. CIH-evoked changes in the carotid body involve reactive oxygen species (ROS)-mediated signaling and transcriptional activation by hypoxia-inducible factor-1. Augmented chemoreceptor sensitivity to hypoxia increases the likelihood of unstable breathing perpetuating the effects of CIH, whereas sensory LTF may contribute to increased sympathetic tone and systemic hypertension associated with recurrent apneas.