Spontaneous Adsorption of Graphene Oxide on Multiple Polymeric Surfaces.

The controllable integration of low-dimensional nanomaterials on solid surfaces is pivotal for the fabrication of next-generation miniaturized electronic and optoelectronic devices. For instance, organization of two-dimensional (2D) nanomaterials on polymeric surfaces paves the way for the development of flexible electronics for applications in wearable devices. Nevertheless, the understanding of the molecular interactions between these nanomaterials and the polymeric surfaces remains limited, which impedes the rational design of 2D nanomaterial-based functional coatings. In the current work, we report that graphene oxide (GO) nanosheets, in their dispersion phase, can be adsorbed on multiple polymeric surfaces in a spontaneous manner. Both experimental findings and simulational results indicate that the main driving force is hydrogen bonding interactions, although other molecular interactions such as polarity and dispersion ones contribute to the adsorption as well. The relatively high hydrogen bonding interactions cause not only increased GO surface coverage but also enhanced GO adsorption kinetics on polymeric surfaces. The adsorbed GO layers are robust, which can be explained by the large aspect ratios of GO nanosheets and the presence of multiple spots for molecular interactions. As a proof of concept, GO-covered polymethyl methacrylate effectively decreases surface static charges when compared with its pristine counterpart. The integration of the GO constituents turns many inert polymeric substrates into multifunctional hybrids, and the functional groups on GO can be used further to bridge with additional functional materials for the development of high-performance electronic devices.

Anaerobic-anoxic-oxic biological treatment of high-strength, highly recalcitrant polyphenylene sulfide wastewater.

This paper outlines an integrated anaerobic-anoxic-oxic (A2O) treatment scheme for high-strength, highly recalcitrant wastewater from the production of polyphenylene sulfide (PPS) resins and their composite chemicals. An integrated anaerobic granular sludge blanket (GSB) and anoxic-oxic (AO) reactor indicated that the A2O removed chemical oxygen demand (COD) of up to 7,043 mg/L with no adverse impact from high total dissolved solids (25,000 mg/L) on the GSB COD removal and effluent suspended solids. At a Total Kjeldahl Nitrogen (TKN) nitrification load of 0.11 g TKN/L.d and 400 mg NH3/L, almost 99 % of the NH3 was degraded with effluent NH3 < 5 mg/L, meeting the limit of 35 mg/L. High S2- levels of up to 1470 mg/L can be transformed through aerobic microbial degradation to meet a limit of 1.0 mg/L. With proper microbial acclimation and process designs, the integrated A2O scheme offers a resilient and robust treatment for high-strength recalcitrant PPS wastewater.

Three Nutritional Indices Are Effective Predictors of Mortality in Patients With Type 2 Diabetes and Foot Ulcers.

Introduction: Malnutrition has been associated with mortality in various diseases. This retrospective cohort study aimed to investigate the relationship between three nutritional indices and all-cause mortality in patients with diabetic foot ulcers (DFUs). Materials and Methods: A total of 771 patients diagnosed with DFUs in the First Affiliated Hospital of Wenzhou Medical University from 2015 to 2019 were included in this retrospective cohort study. Patients were classified as high nutritional risk groups or low nutritional risk groups according to the optimal cut-off values of the geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI), and controlling nutritional status (CONUT), respectively. The associations of three nutritional indices with all-cause mortality were evaluated by multivariable Cox regression analyses. Results: Log-rank tests indicated that patients with high nutritional risk had lower overall survival rates (all p < 0.001). The multivariable Cox regression revealed that low GNRI (adjusted HR 2.01, 95% CI: 1.37-2.96, P < 0.001), low PNI (adjusted HR 2.04, 95% CI: 1.29-3.23, P = 0.002) and high CONUT (adjusted HRs 1.54, 95% CI: 1.07-2.23, P = 0.021) were independently associated with high all-cause mortality. In subgroup analyses, only GNRI predicted higher all-cause mortality in patients with severe DFUs, while all of the three indices persisted as independent prognostic factors in patients with no severe DFUs. Discussion: The present study demonstrated that three nutritional indices were effective predictors of all-cause mortality in patients with DFUs. Routine screening for malnutrition using any of the three nutritional indices might be a simple and effective way to identify high-risk patients with DFUs. GNRI can be used as an independent prognostic indicator in patients with severe DFUs.

How Much Is the Eco-Efficiency of Agricultural Production in West China? Evidence from the Village Level Data.

This study evaluates the eco-efficiency of agriculture in Pupiao Town, in the Yunnan province of China, through micro-level research. The term "eco-efficiency" refers to the efficiency with which ecological resources are used to meet human needs. Interviews and field research were conducted to collect the data of the 23 villages from 2016 to 2018. The Data Envelopment Analysis model (DEA) was used for data analysis. The results were as follows: (1) The eco-efficiency scores of Pupiao Town had considerable spatial heterogeneity, exhibiting a general trend of higher in the middle and lower in the east and west, which suggested eco-efficiency may be correlated with topography and transportation. (2) The value of eco-efficiency for the entire town had considerable areas for improvement and showed a slow-growth trend. (3) Fertilizers, pesticides, agricultural diesel, agricultural carbon emission, and non-point source pollution had a significant impact on eco-efficiency, followed by agricultural labor and arable land. (4) Agricultural chemicals were primary determinants affecting eco-efficiency. Most of the factors had a stronger effect on the eastern and western regions. The study suggests that transportation should be improved to promote the conveyance of market information and the application of more efficient and productive farm methods. The most important way is to improve effective utilization and to reduce the amount of agricultural chemicals. In addition, it is necessary to offer technical training and help to support farmers in upgrading their farm operations.