Barium alginate as a skeleton coating graphene oxide and bentonite-derived composites: Excellent adsorbent based on predictive design for the enhanced adsorption of methylene blue.

The phenomenon that calcium alginate does not exhibit high adsorption capacity as a carrier material has not been reasonably explained or solved. In this paper, a new viewpoint that the orbital energy level of metal ions and the binding degree of the α-l-guluronate and ß-d-mannuronate units affect the adsorption performance of the composite was innovatively proposed. Taking barium alginate (BA) as an example, the possibility of replacing calcium alginate is discussed. Barium alginate/graphene oxide (BA/GO) membranes and three-dimensional (3D) barium alginate-bentonite-graphene oxide derived (3D-BA) hydrogels were prepared by vacuum freeze-drying to remove methylene blue. The structure and morphology of the prepared adsorbents were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy. The effects of adsorbent dosage, doping ratio, temperature, contact time, pH value and initial dye concentration on the adsorption performance of BA composites were investigated. The adsorption capacities of the BA/GO and 3D-BA materials were 1011.3 and 710.3 mg/g, respectively. The BA/GO membrane exhibited stable filtration performance against high concentrations of dyes. Benefiting from the strong interaction between bentonite, sodium alginate and Ba2+, the 3D-BA hydrogel showed higher thermal stability and better adsorption efficiency than other materials. The Elovich kinetic model and Sips equation can appropriately describe the adsorption process. The results show that barium alginate is a better carrier material than calcium alginate.

Adsorption of methylene blue by Nicandra physaloides(L.) Gaertn seed gum/graphene oxide aerogel.

In this study, a novel composite aerogel of Nicandra physaloides(L.) Gaertn seed, gum/graphene oxide (NPG/GO), was prepared by using a vacuum freeze drying method for methylene blue (MB) adsorption. The techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), were adopted for studying the structure and surface characteristics of NPG/GO, with thermogravimetric analysis (TGA) being adopted for testing thermal properties. The effects of pH value, initial dye concentration, temperature and adsorbent dosage on adsorption performance were elaborately analysed. The adsorption kinetic studies showed that the process of adsorption follows Langmuir isotherm and a pseudo-second-order kinetic model. When the mass ratio of NPG to GO was 1.25:1, the adsorption capacity was the highest. According to Langmuir isotherm, the maximum adsorption capacity of 408.16 mg/g was higher than that of NPG. The specific surface area and average pore diameter of NPG/GO was measured as 2.70 m2/g and 4.8 nm, respectively. Thermodynamic analysis revealed that the adsorption process of methylene blue on NPG/GO was a spontaneous and endothermic process. In general, the prepared nanocomposites were excellent candidates for adsorption and removal process because of simple synthesis, low cost, high efficiency, non-toxicity, environment protection and degradability.

Study on the Adsorption Performance of Casein/Graphene Oxide Aerogel for Methylene Blue.

Casein (CS) and graphene oxide (GO) were employed for the fabrication of a casein/graphene oxide (CS/GO) aerogel by vacuum freeze drying. Fourier transform infrared spectroscopy, scanning electron microscopy, surface area and micropore analysis (BET), and thermogravimetric analysis were used to characterize the specific surface area, structure, thermal stability, and morphology of the CS/GO aerogel. The influence of experimental parameters such as the GO mass fraction in the aerogel, metering of the adsorbent, pH, contact time, and temperature on the adsorption capacity of the CS/GO aerogel on methylene blue (MB) was also investigated. According to Langmuir isotherm determination, the maximum removal rate of MB from the CS/GO aerogel was 437.29 mg/g when the temperature was 293 K and pH was 8. Through kinetic and thermodynamic studies, it is found that adsorption follows a pseudo-second-order reaction model and is also an exothermic and spontaneous process.

The prevalence of mild cognitive impairment with type 2 diabetes mellitus among elderly people in China: A cross-sectional study.

BACKGROUND: In absence of curative treatments for dementia with type 2 diabetes mellitus (T2DM), mild cognitive impairment (MCI) in T2DM, the preclinical transitional states of dementia with T2DM has attracted dramatic attention. Our study was to estimate the prevalence and distribution of MCI in T2DM subjects from China, and identify influencing factors of subjects in MCI with T2DM. METHODS: In the present study, we performed cluster random sampling of 8213 people aged 65 years and older in Tianjin, a metropolitan city, located in northern China. All participants were interviewed and screened for T2DM. 1109 subjects with T2DM were initially screened with American Diabetes Association criteria for diagnosis of diabetes mellitus and were diagnosed with MCI and dementia according to the criteria of DSM-IIIR. The prevalence of MCI and dementia in subjects with T2DM were compared with that in ordinary subjects. Logistic regression analyses were performed to evaluate risk of MCI with T2DM. RESULTS: Among all 8213 subjects, overall MCI and dementia with T2DM prevalence were 13.5% and 2.34%, respectively. Compared with ordinary subjects, the prevalence of MCI in the present study was more frequent than the prevalence of MCI for the general population in almost each age group. In the univariate analyses, among all diabetic subjects, compared with cognitive intactly subjects, MCI subjects had significantly higher levels of age, current smoking, mean waist circumference, duration from onset of diabetes, insulin intake, systolic BP, fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c) and immunoreactive insulin (IRI). In multivariate logistic regression analyses, variables including current smoking, duration from onset of diabetes, FPG, HbA1c and IRI were significantly associated with increased risk for MCI with T2DM, the ORs were 1.36,1.33,1.17,1.25 and 1.33, respectively (all P<0.05). CONCLUSIONS: The present study confirms the high prevalence of MCI with T2DM among the elderly population of China. T2DM is related to a higher risk of MCI in a population with a high prevalence of this disorder and may aggravate the clinical picture as a concomitant factor.

The zinc cluster protein Sut1 contributes to filamentation in Saccharomyces cerevisiae.

Sut1 is a transcriptional regulator of the Zn(II)(2)Cys(6) family in the budding yeast Saccharomyces cerevisiae. The only function that has been attributed to Sut1 is sterol uptake under anaerobic conditions. Here, we show that Sut1 is also expressed in the presence of oxygen, and we identify a novel function for Sut1. SUT1 overexpression blocks filamentous growth, a response to nutrient limitation, in both haploid and diploid cells. This inhibition by Sut1 is independent of its function in sterol uptake. Sut1 downregulates the expression of GAT2, HAP4, MGA1, MSN4, NCE102, PRR2, RHO3, and RHO5. Several of these Sut1 targets (GAT2, HAP4, MGA1, RHO3, and RHO5) are essential for filamentation in haploids and/or diploids. Furthermore, the expression of the Sut1 target genes, with the exception of MGA1, is induced during filamentous growth. We also show that SUT1 expression is autoregulated and inhibited by Ste12, a key transcriptional regulator of filamentation. We propose that Sut1 partially represses the expression of GAT2, HAP4, MGA1, MSN4, NCE102, PRR2, RHO3, and RHO5 when nutrients are plentiful. Filamentation-inducing conditions relieve this repression by Sut1, and the increased expression of Sut1 targets triggers filamentous growth.