ABSTRACT
The assembly of supertetrahedral chalcogenolate clusters (SCCs) and multifunctional organic linkers could lead to the formation of tunable structures and synergistic properties. Two SCC-based assembled materials (SCCAM-1 and -2) constructed by a triangular chromophore ligand, tris(4-pyridylphenyl)amine, were successfully synthesized and characterized. The SCCAMs demonstrate unusually long-lived afterglow at low temperatures (83 K) and efficient activities for the photocatalytic degradation of organic dye in water.
ABSTRACT
The development of sorbents for flue gas desulfurization in a dry mode is essential to control emission of sulfur dioxide. Based on the novel concept of "treating waste with waste", a low-cost and highly activated calcium-based sorbent (ACS) was prepared using coal fly ash, CaO and waste gypsum as the raw materials via the one-step incipient wetness impregnation method. Based on characterization using scanning electron microscopy and nitrogen adsorption-desorption, the ACS possessed a fibrous and netted structure with high porosity, which improved SO2 adsorption greatly. The SO2 adsorption capacity of ACS with coal fly ash/CaO/CaSO4 = 1/2/1 was high, up to 44.26 mg g-1, with 100% removal efficiency at 150 °C. In the absence of O2, SO2 was rapidly adsorbed on the sorbent to form CaSO3 according to in situ DRIFTS analysis, while when O2 was present in the flue gas, SO2/SO3 2- tended to be oxidized into SO4 2- species. Moreover, the presence of NO can further enhance the SO2 adsorption capacity of the ACS due to the formation of adsorbed NO2 or nitrate species with strong oxidizing properties. Therefore, the ACS can be considered as a sustainable sorbent with the advantage of employing fly ash for the removal of sulfur dioxide.
ABSTRACT
Oceanic oil spill and the discharge of industrial oily wastewaters can cause significant threats to the ecological environment and human health. Herein, we design a durable TiO2/PDA-based superhydrophobic paper for efficient oil/water separation. Bioinspired from mussel adhesive proteins, the mechanical durability of the as-prepared superhydrophobic paper is enhanced by the deposition of polydopamine (PDA) onto cellulosic fibers via self-polymerization of dopamine. The TiO2/PDA-based superhydrophobic paper shows a high water contact angle of 168.2° and an oil contact angle of â¼0°, exhibiting excellent superhydrophobicity and superoleophilicity. Furthermore, the as-prepared superhydrophobic paper possesses excellent chemical stability, thermal stability, and mechanical durability in terms of being immersed in corrosive solutions and solvents and boiling water and being subjected to the sandpaper abrasion test, respectively. More importantly, the separation efficiency of the TiO2/PDA-based superhydrophobic paper for an oil/water mixture is 97.2%, and it maintains a separation efficiency above 94.3% even after 15 cyclic separation processes. Furthermore, the separation efficiency for water-in-oil emulsions is higher than 93.7% after 15 cyclic separation tests, showing its excellent recyclable stability for water-in-oil emulsions. Therefore, the rationally designed TiO2/PDA-based superhydrophobic paper shows great potential in the practical applications of self-cleaning, antifouling, and oil/water separation.
Subject(s)
Polymers , Emulsions , Humans , Hydrophobic and Hydrophilic Interactions , Indoles , Polymers/chemistry , TitaniumABSTRACT
Men who have sex with men (MSM) have recently accounted for an alarmingly increasing proportion of HIV-1 transmission in China. In order to investigate the immune status as a result of CRF01_AE infection and CXCR4 co-receptor usage in a young Shanghai-based HIV-1-infected MSM population in Shanghai, 364 HIV-1-infected MSM with average age of 22.7 years old, newly diagnosed between Jan 2009 and Jul 2013 were analyzed for CD4+T cell count, subtyping using phylogenetic analysis, and viral co-receptor tropism using Geno2pheno and webPSSM in combination. A total of 276 individuals were identified as recently infected. Subtype assignment were as follows: 176 (63.8%) CRF01_AE, 77 (27.9%) CRF07_BC, and 23 (8.3%) subtype B. Besides, 24 second-generation recombinant strains were identified. A lower CD4+T cell count at baseline survey was observed among CRF01_AE strain-infected individuals, compared to those who were infected with CRF07_BC (P<0.01). The frequency of baseline CD4+T cell count <200 was higher and the frequency of CD4 T counts >500 lower in CRF01_AE infection than CRF07_BC infection. It is worth noting that 32.4%-40.9% of CRF01_AE strain-infected individuals were predicted to carry CXCR4-tropic viruses whereas none of CRF07_BC and subtype B were found to be as CXCR4-tropic viruses (P<0.001). As could be expected CXCR4 tropism was associated with lower CD4 T counts. This study revealed that CRF01_AE strains with high frequency of CXCR4 tropism are prevailing in the young MSM population in China and could potentially cause a severe loss of CD4+T cell count and rapid disease progression. A regular surveillance of HIV-1 subtypes, CD4+T cell count and viral co-receptor usage would be greatly beneficial for effectively monitoring disease progression, improvement of antiretroviral therapy strategy and prompt intervention of transmission.
Subject(s)
CD4-Positive T-Lymphocytes/metabolism , HIV Infections/immunology , HIV Seropositivity/immunology , Homosexuality, Male , Receptors, CXCR4/metabolism , Adolescent , Adult , China , HIV Infections/metabolism , HIV Seropositivity/metabolism , Humans , Lymphocyte Count , Male , Young AdultABSTRACT
Trait differences between invasive and native species are believed to be closely related to whether the former are successful. However, few studies have measured trait differences between invasive and native species directly under field conditions or during long term experiments. We examined the phenological pattern, plant height and biomass accumulation and allocation of Crofton weed (Eupatorium adenophorum Spreng.) and co-occurring native species in a community during a three-year succession. The phenological pattern of Crofton weed differed from that of co-occurring native species. Crofton weed had longer vegetative stage (when resources were more available), a higher biomass accumulation and a higher above/below-ground ratio compared to native species. Crofton weed was shorter than grasses and two forbs (Artemisia tangutica and Cynoglossum amabile) during its first year of growth, but was significantly taller than all other species during subsequent years. The dominance (calculated as the importance value) of Crofton weed was the highest among all other species and continually increased over time while the dominance of co-occurring native species decreased. This study provides direct field evidence that trait differences are important to plant invasion.
Subject(s)
Adaptation, Biological/genetics , Ageratina/growth & development , Ecosystem , Poaceae/growth & development , Ageratina/genetics , Biomass , PhenotypeABSTRACT
There are two ways in Symplocos laurina propagation, clonal and sexual reproduction. The study showed that under different habitat conditions, Symplocos laurina could adopt different ways to propagate and occupy space. In conditions with abundant water and nutrient resources, such as in evergreen broad-leaved forests or bamboo forests, the survival rate and space-occupying ability of both ramets and sexual seedlings were relatively high, with clonal ramets took advantage in terms of number and space, suggesting that clonal propagation was the dominant way in such environments. Oppositely, in habitats lack of sufficient nutrition, the survival rate and space-occupying ability of seedlings were low, and grown-up plantlets would preempt in number and space occupation. Bottleneck in sexual propagation appeared in the stage from seed to seedling, while clonal propagation appeared during the period from seedling to ramet. The way of Symplocos laurina invasion was to settle a plantlet, and then occupied the space rapidly by clonal growth, with clonal seedlings dominated in initial stage and lost the advantage after 15 ages.
Subject(s)
Ecosystem , Reproduction, Asexual/physiology , Reproduction/physiology , Trees/physiology , Adaptation, Biological , Environment , Population Density , Seedlings/physiologyABSTRACT
Habitat fragmentation is the primary cause of the loss of biodiversity and ecosystem services, but its underlying processes and mechanisms remain poorly understood. Studies of islands and insular terrestrial habitats are essential for improving our understanding of habitat fragmentation. We argue that the Three-Gorges Dam, the largest that humans have ever created, presents a unique grand-scale natural experiment that allows ecologists to address a range of critical questions concerning the theory and practice of biodiversity conservation.