Rational design of high-performance continuous-flow microreactors based on gold nanoclusters and graphene for catalysis

In this work, we rationally designed a high-performance microreactor system for continuous-flow catalysis. The membrane consists of ultrasmall gold nanoclusters (AuNCs) and two-dimensional graphene. The Au cores of the NCs act as catalysts, while their ligands have two functions: (1) protecting the Au cores to avoid agglomeration and (2) providing a well-defined surfactant assembly to disperse graphene in aqueous solution. Hydrogenation of 4-nitrophenol (4-NP) was employed as model reaction to evaluate catalytic activity. The catalytic membrane microreactor demonstrated excellent catalytic activity and stability, where complete 4-NP conversion was readily achieved via a single pass through the membrane. This desirable performance was maintained over 12 h of continuous operation, although a certain amount of organic buildup on the membrane was observed. The catalytic membrane microreactor outperforms conventional batch reactors due to its improved mass transport. 4-NP-spiked real water samples were also completely converted. This study provides new insights for the rational design of membrane reactors for industrial applications

Subsequent monitoring of ferric ion and ascorbic acid using graphdiyne quantum dots-based optical sensors

Graphdiyne (GDY) as an emerging carbon nanomaterial has attracted increasing attention because of its uniformly distributed pores, highly π-conjugated, and tunable electronic properties. These excellent characteristics have been widely explored in the fields of energy storage and catalysts, yet there is no report on the development of sensors based on the outstanding optical property of GDY. In this paper, a new sensing mechanism is reported built upon the synergistic effect between inner filter effect and photoinduced electron transfer. We constructed a novel nanosensor based upon the newly-synthesized nanomaterial and demonstrated a sensitive and selective detection for both Fe3+ ion and ascorbic acid, enabling the measurements in real clinical samples. For the first time fluorescent graphdiyne oxide quantum dots (GDYO-QDs) were prepared using a facile ultrasonic protocol and they were characterized with a range of techniques, showing a strong blue-green emission with 14.6% quantum yield. The emission is quenched efficiently by Fe3+ and recovered by ascorbic acid (AA). We have fabricated an off/on fluorescent nanosensors based on this unique property. The nanosensors are able to detect Fe3+ as low as 95 nmol L−1 with a promising dynamic range from 0.25 to 200 μmol L−1. The LOD of AA was 2.5 μmol L−1, with range of 10–500 μmol L−1. It showed a promising capability to detect Fe3+ and AA in serum samples

Dominance of HIV-1 Subtype CRF01_AE in Sexually Acquired Cases Leads to a New Epidemic in Yunnan Province of China

BACKGROUND: Dating back to the first epidemic among injection drug users in 1989, the Yunnan province has had the highest number of human immunodeficiency virus type 1 (HIV-1) infections in China. However, the molecular epidemiology of HIV-1 in Yunnan has not been fully characterized. METHODS AND FINDINGS: Using immunoassays, we identified 103,015 accumulated cases of HIV-1 infections in Yunnan between 1989 and 2004. We studied 321 patients representing Yunnan's 16 prefectures from four risk groups, 11 ethnic populations, and ten occupations. We identified three major circulating subtypes: C/CRF07_BC/CRF08_BC (53%), CRF01_AE (40.5%), and B (6.5%) by analyzing the sequence of p17, which is part of the gag gene. For patients with known risk factors, 90.9% of injection drug users had C/CRF07_BC/CRF08_BC viruses, whereas 85.4% of CRF01_AE infections were acquired through sexual transmission. No distinct segregation of CRF01_AE viruses was found among the Dai ethnic group. Geographically, C/CRF07_BC/CRF08_BC was found throughout the province, while CRF01_AE was largely confined to the prefectures bordering Myanmar. Furthermore, C/CRF07_BC/CRF08_BC viruses were found to consist of a group of viruses, including C, CRF08_BC, CRF07_BC, and new BC recombinants, based on the characterization of their reverse transcriptase genes. CONCLUSIONS: This is the first report of a province-wide HIV-1 molecular epidemiological study in Yunnan. While C/CRF07_BC/CRF08_BC and CRF01_AE are codominant, the discovery of many sexually transmitted CRF01_AE cases is new and suggests that this subtype may lead to a new epidemic in the general Chinese population. We discuss implications of our results for understanding the evolution of the HIV-1 pandemic and for vaccine development

Study on carbon-fixing,oxygen-releasing,temperature-reducing and humidity-increasing effects of evergreen plants in south highway

Li-6400 portable photosynthesis system,was used to test the diurnal variations of photosynthetic rate and stomatal conductance of evergreen plants in Southern Highway,and to calculate their ability of absorbing carbon dioxide and releasing oxygen and to calculate the transpiring water volume and absorbing heat quantity of plants.Results showed that Euonymus fortunei Hand-Mazz,Hedera helix.Aucuba eriobotryaefolia had better carbon-fixing and oxygen-releasing effects,while Photinia serrulata,Trachycarpus fortunei,Radix Ophiopogonis had worse carbon-fixing and oxygen-releasing effects.Radix Ophiopogonis,Photinia glabra,Euonymus fortunei Hand.-Mazz had higher cooling and humidification ability,while Photinia serrulata,Trachycarpus fortunei did not act as well as them.Euonymus fortunei Hand.-Mazz and Hedera helix had higher leaf chlorophyll in per unit mass,values are 12.91、10.34、9.93 mg·g-1.Radix Ophiopogonis、Cinnamomum camphora(Linn.) Presl and Trachycarpus fortunei had lower leaf chlorophyll in per unit mass,value is 3.55、2.67、2.06 mg·g-1.Releasing oxygen,fixing carbon,net assimilation and chlorophyll content has good correlation(P＜0.05)

Global Thermoeconomics

This paper illustrates that basic global economic concepts can be directly related to the First and Second Laws of Thermodynamics. We believe that all economic returns are from nothing except from current and past human expenditure of human energy; this is the result of the First Law of Thermodynamics. It is shown that everything is a product of energy in the form of labor and that the basic principle of Labor Theory of Value is still valid and this principle is validated not relying on economics and fi nance models, rather on thermodynamic principles. This is illustrated by the development of the Labor Value Equation based on the application of the First and Second Law of Thermodynamics and how it can impact employment, asset valuation, supply/demand, productivity, global confl ict, global reserve currency and global stabilit

Effects of Habitat Types on Macroinvertebrates Assemblages Structure: Case Study of Sun Island Bund Wetland

Sun Island Bund Wetland (SIBW) is a river floodplain wetland located at the south part of Heilongjiang Province in Northeast China. An investigation of the influence of habitat type on macroinvertebrates assemblages structure was conducted in July 2016. Nine (9) sampling sites were selected based on sediment type, water condition, and aquatic vegetation type. Macroinvertebrates attributes including density, biomass, and four diversity indices (Simpson diversity index, Margalef richness index, Shannon-Weiner index, and Pielou evenness index) were assessed. A total of 53 taxa were collected during the study period, with the highest density dominated being from aquatic insects and gastropods. Bellamya purificata and Exopalaemon annandalei were the most dominant among all the species. The results showed that the assemblages structure of macroinvertebrates in different habitats was significantly different. Also, the results with PCA showed that the higher values of invertebrates density, biomass, diversity indices, and species richness had a greater association with the habitat types of silt-humus sediment, closed lentic area, and submerged-flouting-emergent vegetation