Photocatalytic self-cleaning graphene oxide/ZnO hybrid membrane for ultrafast cyclic small organic molecule separation

Graphene oxide (GO) based membranes have attracted tremendous interest owing to their unique lamellar structure resulting in excellent molecular filtration. However, the expansion of interlayer spacing of GO nanoflakes in liquid solutions, particularly in aqueous solution, and the adsorption of foulants in the layered nanoconfinement as well as on the surface adversely affects the long-term performance of the membranes. In this work, one-dimensional zinc oxide (ZnO) nanorods were integrated with graphene oxide via in-situ crystallization. A fast thermal treatment was applied to partially reduce the graphene oxide nanoflakes and chemically ‘lock’ the newly formed ZnO nanorods during the final step of hybrid membrane fabrication. It was found that the partially reduced graphene oxide (rGO) provided excellent mechanical stability between the nanolayers and also very stable and efficient molecular sieving properties. Interestingly, the ZnO nanorods not only served as a space holder between neighbouring reduced graphene-oxide nanoflakes but also endowed the hybrid membrane with responsive photocatalytic self-cleaning properties, which has been considered one of the most promising approaches for energy-efficient environmental remediation. In water permeation tests, these graphene oxide-zinc oxides (P-rGO/ZnO) membranes exhibited ultrahigh permeance of 400 ± 21 L m−2 h−1 bar−1, more than an order of magnitude higher than the conventional rGO membranes. In the meantime, these membranes exhibited excellent small organic molecule separation efficiencies with &gt;98.8 ± 1.2% rejections toward direct red 80, rose bengal, reactive black 5, and trypan blue. More importantly, under ultraviolet–visible light irradiation, the membrane demonstrated highly efficient self-cleaning behaviour for fast organic dye decomposition, enabling excellent cyclic removal of pre-adsorbed dye molecules. Therefore, this intelligent self-cleaning hybrid membrane has great potential in wastewater purification, particularly for ultrafast small organic molecule removal.</p

Preparation of Graphene/TiO 2

The graphene (GR) was prepared by an improved electrochemical stripping method using a high-purity graphite rod as raw material and high temperature heat reduction in hydrogen atmosphere, and the graphene/TiO2 (GR/TiO2) composite nanomaterials were manufactured by the method of sol-gel and high temperature crystallization in hydrogen atmosphere using butyl titanate and electrolysis graphene as precursors. The physical and chemical properties of the composites had been characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer (UV-Vis), scanning electron microscopy (SEM), Transmission Electron Microscope (TEM),  and specific surface area (SSA) by BET method. The photocatalytic properties of GR/TiO2 composites nanomaterials in anoxic water were studied by using 2,4-dichlorophenoxyacetic acid (2,4-D) as probe. The results showed that graphite was well intercalated and peeled by a facile electrolysis method in different electric field environment; a well dispersed and rings structure of graphene was prepared by coupling ultrasound-assisted changing voltage electrochemical stripping technology. The as-prepared GR/TiO2 composites had good performance for the photocatalytic degradation of 2,4-D in anoxic water; the chlorines were removed from benzene ring; the middle products of dichlorophenol, chlorophenol, phloroglucinol, and so forth were produced from the photocatalytic redox reaction of 2,4-D in anoxic water; parts of 2,4-D were decomposed completely, and CO2 and H2O were produced

Effects of hydrodynamic interaction on random adhesive loose packings of micron-sized particles

Random loose packings of monodisperse spherical micron-sized particles under a uniform flow field are investigated via an adhesive discrete-element method with the two-way coupling between the particles and the fluid. Characterized by a dimensionless adhesion parameter, the packing fraction follows the similar law to that without fluid, but results in larger values due to the hydrodynamic compression. The total pressure drop through the packed bed shows a critical behaviour at the packing fraction of ϕ ≈ 0.22 in the present study. The normalized permeability of the packed bed for different parameters increases with the increase of porosities and is also in consistent with the Kozeny-Carman equation

The Double Burdens of Mental Health Among AIDS Patients With Fully Successful Immune Restoration: A Cross-Sectional Study of Anxiety and Depression in China

Background: Anxiety and depression continue to be significant comorbidities for people with HIV infection. We investigated the prevalence of and factors associated with anxiety and depression among adult HIV-infected patients across China.Methods: In this cross-sectional study, we described clinical and psychosocial variables related to depression and anxiety in 4103 HIV-infected persons. Doctors assessed anxiety and depression by asking patients whether they had experienced anxiety or depression in the prior month. Patients also self-administered the Hospital Anxiety and Depression (HAD) scale; those with score ≥8 on HAD-A/D were considered to be at high risk of anxiety or depression.Results: Associations between socio-demographic, psychosocial, and ART-related clinical factors and risk of depression or anxiety were investigated using multivariable logistic regression. Among patients assessed between 9/2014 and 11/2015, 27.4% had symptoms of anxiety, 32.9% had symptoms of depression, and 19.0% had both. Recentness of HIV diagnoses (P = 0.046) was associated with elevated odds of anxiety. Older age (P = 0.004), higher educational attainment (P &lt; 0.001), employment (P = 0.001), support from family / friends (P &lt; 0.001), and sleep disturbance (P &lt; 0.001), and number of ART regimen switches (P = 0.046) were associated with risk of depression, while neither sex nor transmission route showed any associations. There were no significant associations with HIV-specific clinical factors including current CD4+ T cell count and current viral load.Conclusions: Prevalence of symptoms of anxiety and depression is high in this cohort of treatment-experienced HIV patients. Psychological and social-demographic factors, rather than HIV disease status, were associated with risk of depression and anxiety. This finding highlights the need to deliver interventions to address the mental health issues affecting HIV-infected persons with fully successful immune restoration across China

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe

An analysis on domestic users' awareness towards Open Access resources: A case study of university users in Nanjing

Based on a survey of university teachers and students in Nanjing area of 2007, this article analyzes domestic users' awareness towards Open Access (OA), and the changes by comparing the corresponding data of 2006. The survey shows that the research evaluation system, the quality of literature and the payment for OA publications are the important factors for university users to choose OA or not. The authors finally suggest that the current research evaluation system should be reformed to accommodate OA journals. Meanwhile, great efforts should be devoted to improve the quality of OA literatures, and the governments and research institutions should provide stronger support than before.</p

Cross-efficiency DEA model-based evaluation of allocative efficiency of rural information resources in Jiangsu Province, China

Purpose: This paper aims to compare and rank the allocative efficiency of information resources in rural areas by taking 13 rural areas in Jiangsu Province, China as the research sample.Design/methodology/approach: We designed input and output indicators for allocation of rural information resources and conducted the quantitative evaluation of allocative efficiency of rural information resources based on cross-efficiency model in combination with the classical CCR model in data envelopment analysis (DEA).Findings: Cross-efficiency DEA model can be used for our research with the objective to evaluate quantitatively and objectively whether the allocation of information resources in various rural areas is reasonable and whether the output is commensurate with the input.Research limitations: We have to give up using some indicators because of limited data availability. There is a need to further improve the cross-efficiency DEA model because it cannot identify the specific factors influencing the efficiency of decision-making units (DMUs).Practical implications: The evaluation results will help us understand the present allocative efficiency levels of information resources in various rural areas so as to provide a decision making basis for formulation of the policies aimed at promoting the circulation of information resources in rural areas.Originality/value: Little or no research has been published about the allocative efficiency of rural information resources. The value of this research lies in its focus on studying rural informatization from the perspective of allocative efficiency of rural information resources and in the application of cross-efficiency DEA model to evaluate allocative efficiency of rural information resources as well.</p