Macroinvertebrate community dynamics following wetland restoration: Insights from taxonomic structure and functional feeding groups in response to water quality.

Continuous wetland restoration initiatives in China are increasing, due to the global degradation of wetland ecosystems. However, monitoring of the restoration situation remains incomplete. In this study, we investigated the effects of wetland restoration on the macroinvertebrate taxonomic structure and feeding functional groups (FFGs) in the Naolihe National Nature Reserve (NNNR). Macroinvertebrate taxonomic diversity can be used to monitor wetlands, and we hypothesized that FFGs serve the same function. We calculated the diversity index, performed a non-metric multidimensional analysis based on macroinvertebrate taxonomics and FFGs, and subsequently, performed a t-test on the results. The results showed that macroinvertebrate diversity and FFGs analyses were in general agreement with taxonomic diversity, indicating that the macroinvertebrate community in the wetland with five years of fallow land was resembled that of the natural wetland. In contrast, the macroinvertebrate community in the wetland with two years of fallow differed significantly from that in the natural wetland. Additionally, the results of the ecosystem attributes based on biomass and FFGs showed that restored wetlands exhibited lower habitat stability than natural wetlands. Nutrients (NH4 +-N, NO3 --N, and total phosphorus) explained the changes in macroinvertebrate FFGs in the restored wetlands to a greater extent than in the natural wetlands. The results of this study highlight the importance of macroinvertebrate FFGs in wetland monitoring, which supports the use of macroinvertebrate FFGs in the NNNR to monitor wetland restoration.

The Driving Mechanism of Phytoplankton Resource Utilization Efficiency Variation on the Occurrence Risk of Cyanobacterial Blooms.

Algae are highly sensitive to environmental factors, especially nutrient fluctuations; excessive nutrients can lead to the proliferation of specific algae species, resulting in dominance. In this study, we aimed to reevaluate changes in algal dominance from the perspective of resource utilization efficiency (RUE). We established 80 monitoring sites across different water systems, collecting water and phytoplankton samples. Using canonical correspondence analysis (CCA) and a generalized additive model (GAM), we analyzed the correlation between phytoplankton RUE and nutrient concentrations, quantifying the corresponding relationship between algal dominance and RUE. Our results indicate a significant negative correlation between the RUE of total phosphorus (TP) and total nitrogen (TN) concentration, but a positive correlation with N:P. The RUE of TN was negatively correlated with TN concentration and N:P. We constructed GAMs with interaction terms and confirmed a nonlinear relationship between algal dominance and RUE. When the RUE of TN was low, a positive correlation was observed, while a negative correlation was observed otherwise. These findings reveal the ecological adaptability of algal communities and provide valuable insights for predicting the risk of algal bloom outbreaks.

Characterization and trans-generation dynamics of mitogene pool in the silver carp (Hypophthalmichthys molitrix).

Multicopied mitogenome are prone to mutation during replication often resulting in heteroplasmy. The derived variants in a cell, organ, or an individual animal constitute a mitogene pool. The individual mitogene pool is initiated by a small fraction of the egg mitogene pool. However, the characteristics and relationship between them has not yet been investigated. This study quantitatively analyzed the heteroplasmy landscape, genetic loads, and selection strength of the mitogene pool of egg and hatchling in the silver carp (Hypophthalmichthys molitrix) using high-throughput resequencing. The results showed heteroplasmic sites distribute across the whole mitogenome in both eggs and hatchlings. The dominant substitution was Transversion in eggs and Transition in hatching accounting for 95.23%±2.07% and 85.38%±6.94% of total HP sites, respectively. The total genetic loads were 0.293±0.044 in eggs and 0.228±0.022 in hatchlings (P=0.048). The dN/dS ratio was 58.03±38.98 for eggs and 9.44±3.93 for hatchlings (P=0.037). These results suggest that the mitogenomes were under strong positive selection in eggs with tolerance to variants with deleterious effects, while the selection was positive but much weaker in hatchlings showing marked quality control. Based on these findings, we proposed a trans-generation dynamics model to explain differential development mode of the two mitogene pool between oocyte maturation and ontogenesis of offspring. This study sheds light on significance of mitogene pool for persistence of populations and subsequent integration in ecological studies and conservation practices.

Effects of different restoration stages on soil microbial community composition and diversity in Naolihe Wetland, China.

Soil microorganisms can be used as one of the important indicators of wetland ecosystem restoration. To study the effects of different restoration stages on soil microbial community composition and diversity in Naolihe Wetland, we employed a "time and space parallel" method. Four restoration stages, namely corn field (Corn), short-term restoration wetland (2 years, ST), long-term restoration wetland (8 years, LT) and natural wetland (>25 years, NW), were selected to represent the restoration time and geographical location in Naolihe Nature Wetland. We investigated the composition and diversity of soil microbial communities in different restoration wetland (from corn fields to natural wetlands) by using 16S rRNA and ITS rRNA gene sequencing. We also performed chemical experiments to measure soil enzyme activity and physicochemical properties at each sampling site. The results showed that soil physicochemical properties and enzyme activities significantly differed with the extension of wetland restoration years (p < 0.05). Proteobacteria, Acidobacteria, and Actinobacteria are the most dominant phyla in bacterial. The alpha diversity of soil bacteria was the highest in the corn field (Corn), and ST-LT-NW first decreased and then increased with the extension of wetland restoration years. There are two most dominant phyla (Ascomycota and Mucoromycota) in fungal. However, the alpha diversity of soil fungi was the lowest in the Corn and LT stage, and ST-LT-NW first decreased and then increased with the extension of wetland restoration years. The research findings indicated that the changes in soil physicochemical properties with the extension of wetland restoration years play a significant role in shaping the structure and diversity changes of soil microbial communities. Through the analyses of bacterial and fungal functions using the FUNGuild and FAPROTAX databases, the results showed that the abundance of aerobic bacteria in the soil increased more than that of anaerobic bacteria as the wetland restoration years prolonged, while the abundance of saprotrophic, symbiotic, and pathogenic fungi in the soil significantly decreased with the prolonged wetland restoration years. This study will help us better understand the process of restoration after farmland abandonment, providing valuable reference information for the implementation of a series of wetland ecological restoration projects in the future.

A new species of Trychosis Förster (Hymenoptera, Ichneumonidae, Cryptinae), with a key to the species known from China.

A new species of Ichneumonidae, Trychosisnaolihense Meng & Ren, sp. nov., is described and illustrated. Specimens were collected from Naolihe National Natural Reserve, Heilongjiang Province, China. A key to the currently known species from China is provided.

Ultrathin Graphdiyne/Graphene Heterostructure as a Robust Electrochemical Sensing Platform.

Graphdiyne (GDY) has been considered as an appealing electrode material for electrochemical sensing because of its alkyne-rich structure and high degrees of π-conjugation, which shows great affinity to heavy metal ions and pollutant molecules via d-π and π-π interactions. However, the low surface area and poor conductivity of bulk GDY limit its electrochemical performance. Herein, a two-dimensional ultrathin GDY/graphene (GDY/G) nanostructure was synthesized and used as an electrode material for electrochemical sensing. Graphene plays the role of an epitaxy template for few-layered GDY growth and conductive layers. The formed few-layered GDY with a high surface area possesses abundant affinity sites toward heavy metal ions (Cd2+, Pb2+) and toxic molecules, for example, nitrobenzene and 4-nitrophenol, via d-π and π-π interactions, respectively. Moreover, hemin as a key part of the enzyme catalytic motif was immobilized on GDY/G via π-π interactions. The artificial enzyme mimic hemin/GDY/G-modified electrode exhibited promising ascorbic acid and uric acid detection performance with excellent sensitivity and selectivity, a good linear range, and reproducibility. More importantly, real sample detection and the feasibility of this electrochemical sensor as a wearable biosensor were demonstrated.

Piezoelectric Activatable Nanozyme-Based Skin Patch for Rapid Wound Disinfection.

Nanozymes are promising new-generation antibacterial agents owing to their low cost, high stability, broad-spectrum activity, and minimal antimicrobial resistance. However, the inherent low catalytic activity of nanozymes tends to limit their antibacterial efficacy. Herein, a heterostructure of zinc oxide nanorod@graphdiyne nanosheets (ZnO@GDY NR) with unparallel piezocatalytic enzyme mimic activity is reported, which concurrently possesses intrinsic peroxidase-like activity and strong piezoelectric responses and effectively promotes the decomposition of hydrogen peroxide (H2O2) and generation of reactive oxygen species under ultrasound irradiation. Moreover, this piezocatalytic nanozyme exhibits almost 100% antibacterial efficacy against multidrug-resistant pathogens involving methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in vitro and in vivo. In addition, a piezoelectric activatable nanozyme-based skin patch is developed for rapid skin wound disinfections with satisfactory hemocompatibility and cytocompatibility. This work not only sheds light on the development of an innovative piezoelectric activatable nanozyme-based skin patch for rapid wound disinfection but also provides new insights on the engineering of piezocatalytic nanozymes for nanozyme antibacterial therapy.

Comparative transcriptome reveals the thermal stress response differences between Heilongjiang population and Xinjiang population of Lota lota.

Some cold-water fishes are particularly sensitive to the water temperature increasing caused by current global warming. However, the alterations in the physiology and behavior of infraspecific populations living in heterogeneous landscapes in response to water temperature increasing were significantly different. Consequently, understanding the impact of temperature increasing on different populations may be crucial for the conservation of cold-water fishes in the context of global warming. The burbot is the only freshwater specie in Gadiformes. To better understand the differences of different populations of burbot under similar thermal stress, Lota lota was selected as the research objects. Firstly, RNA-seq was applied to identify the transcriptomic responses of Heilongjiang population exposed to three temperature gradients (0 °C, 18 °C and 28 °C). Compared with 0 °C, 4216 and 12,657 genes were significantly differentially expressed at 18 °C and 28 °C, respectively. Meanwhile, 49 genes were significantly differentially expressed in three temperature pairs and these genes were presumed to involve in stress response process, immunologic process, reproductive process, development process, material metabolism process, signal transduction process, spermatogenesis process and cell apoptosis process. The response differences of two L. lota populations to similar thermal stress were compared and the results showed that they have different gene expression responses (the number of differentially expression genes and biological processes). The lower annual temperature of the Heilongjiang River might make it more sensitive to temperature increasing. Based on the comparative transcriptome analyses, 12 orthologous genes were considered as the potential regulators of L. lota preference for cold-water environment and these genes are potentially related to the immunologic process, reproductive process, development process, signal transduction process, and cell apoptosis process. Those results can provide basic information for the rational development of conservation strategies of different L. lota populations under the background of global warming.

Biomimetic design of graphdiyne supported hemin for enhanced peroxidase-like activity.

Effective electronic interactions between molecular catalysts and supports are critical for heterogeneous enzyme mimics, yet they are frequently neglected in most catalyst designs. Taking the enzyme mimics of hemin immobilized on graphdiyne (Hemin-GDY) as an example, we explicate for the first time the underlying role of GDY as a co-catalyst. Based on the robust conjugation between GDY and hemin, the delocalized π-electrons in GDY act as a ligand for Fe ions so that the orbital interactions including electron transport from GDY â†’ Fe can induce the formation of an electron-rich Fe center and an electron-deficient π-electron conjugated system. This mechanism was validated by electron paramagnetic resonance (EPR), Raman spectroscopy, and DFT calculations. Moreover, both EPR spetra and Lineweaver-Burk plots revealed that Hemin-GDY could efficiently catalyze the decomposition of hydrogen peroxide (H2O2) to produce hydroxyl radical (•OH) and superoxide anion (O2•-) by a ping-pong type catalytic mechanism, and particularly, the catalytic activity was increased by 2.3-fold comparing to that of hemin immobilized on graphene (Hemin-GR). In addition, Hemin-GDY with the exceptional activity and stability was demonstrated for efficient catalytic degradation of organic pollutants under acidic conditions. Collectively, this work provides a theoretical basis for the design of GDY supported catalysts and renders great promises of the GDY based enzyme mimics.

Chromosome-level genome assembly of burbot (Lota lota) provides insights into the evolutionary adaptations in freshwater.

The burbot (Lota lota) is the only member of the order Gadiformes adapted solely to freshwater. This species has the widest longitudinal range among freshwater fish worldwide. Burbot serves as a good model for studies on adaptive genome evolution from marine to freshwater environments. However, a high-quality reference genome of burbot has not yet been released. Here, the first chromosome-level genome of burbot was constructed using PacBio long sequencing and Hi-C technology. A total of 95.24 Gb polished PacBio sequences were generated, and the preliminary genome assembly was 575.83 Mb in size with a contig N50 size of 2.15 Mb. The assembled sequences were anchored to 22 pseudochromosomes by using Hi-C data. The final assembled genome after Hi-C correction was 575.92 Mb, with a contig N50 of 2.01 Mb and a scaffold N50 of 22.10 Mb. A total of 22,067 protein-coding genes were predicted, 94.82% of which were functionally annotated. Phylogenetic analyses indicated that burbot diverged with the Atlantic cod approximately 43.8 million years ago. In addition, 377 putative genes that appear to be under positive selection in burbot were identified. These positively selected genes might be involved in the adaptation to the freshwater environment. These genome data provide an invaluable resource for the ecological and evolutionary study of the order Gadiformes.

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. Graphical abstract.

Antibacterial Activity of Graphdiyne and Graphdiyne Oxide.

From manufacture to disposal, the interaction of graphdiyne based nanomaterials with living organisms is inevitable and crucial. However, the cytotoxic properties of this novel carbon nanomaterial are rarely investigated, and the mechanisms behind their cytotoxicity are totally unknown. In this study, the antibacterial activity of graphdiyne (GDY) and graphdiyne oxide (GDYO) is reported. GDY is capable of inhibiting broad-spectrum bacterial growth while exerting moderate cytotoxicity on mammalian cells. In comparison, GDYO exhibits lower antibacterial activity than that of GDY. Then an alterable, synergetic antibacterial mechanism of GDY, involving wrapping bacterial membrane, membrane insertion and disruption, and reactive oxygen species generation is demonstrated, while the differential gene expression analysis indicates that GDY could only alter the bacterial metabolism slightly and the oxidative stress route may be a minor bactericidal factor. The investigation of the antibacterial behaviors of GDY based nanomaterials may provide useful guidelines for the future design and application of this novel molecular allotrope of carbon.

Shape- and size-dependences of gold nanostructures on the electrooxidation of methanol under visible light irradiation.

Plasmonic metal nanocatalysts have excellent light trapping properties and high chemical reactivity. Impressively, Au nanostructures can absorb a wide array of visible light by tuning their morphology. In this work, spherical gold nanoparticles (Au NSs), multi-branched gold nanoparticles (Au NMs) and gold nanorods (Au NRs) were successfully synthesized; the shape- and size-dependences of these gold nanocatalysts on the methanol oxidation reaction (MOR) under light irradiation were studied. It is worth mentioning that Au NRs have the highest anode peak current density under dark conditions due to the exposure of highly active facets. A similar enhancement effect was obtained for Au NSs and Au NMs under visible light irradiation, which is due to the generation of a high concentration of energetic charge carriers on these Au nanostructures. The size dependences of Au NSs on the MOR showed that a larger electrochemically active surface area (ECSA) was obtained for small nanoparticles, which is due to the surface effect. In addition, the catalytic performance, durability and anti-CO stripping of these Au nanocatalysts under visible light irradiation, as well as the effect of light intensity and wavelength were described in detail. This work provides an insight into the mechanism of plasmon enhanced electrocatalysis by Au nanostructures with different sizes and shapes.

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.

Etched PtCu nanowires as a peroxidase mimic for colorimetric determination of hydrogen peroxide.

Etched PtCu nanowires (NWs) were synthesized by a hydrothermal reaction and chemical etching process. The NWs are shown to be viable peroxidase (POx) mimics capable of catalyzing the oxidation of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to form a blue-green coloration. The mechanism of catalysis was investigated and the results demonstrated that H2O2 is decomposed to form hydroxyl radicals which oxidize TMB in the presence of the NWs. Under optimized conditions, a steady-state kinetic analysis revealed that the NWs possess a stronger affinity for H2O2 and TMB compared to the enzyme horseradish POx. Based on the high POx-like activity, a colorimetric assay for H2O2 was established. Absorbance at 652 nm increases linearly in the 0.1-300 µM H2O2 concentration range, and the detection limit is 0.06 µM (at S/N = 3). The assay was successfully applied to the determination of H2O2 in (spiked) milk and contact lens solution. Furthermore, a highly sensitive test strip was designed which represents a low cost and fast alternative for the visual determination of H2O2. Graphical Abstract Schematic presentation of the colorimetric detection of H2O2. PtCu nanowires (PtCu NWs) can catalyze 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2 to produce blue-green oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB). Based on the color change, test strips were designed for H2O2 detection.

Facile synthesis of hollow dendritic Ag/Pt alloy nanoparticles for enhanced methanol oxidation efficiency.

Hollow dendritic Ag/Pt alloy nanoparticles were synthesized by a double template method: Ag nanoparticles as the hard template to obtain hollow spheres by a galvanic replacement reaction between PtCl62- and metallic Ag and surfactant micelles (Brij58) as the soft template to generate porous dendrites. The formation of a Ag/Pt alloy phase was confirmed by XRD and HRTEM. Elemental mapping and line scanning revealed the formation of the hollow architecture. We studied the effects of the Ag/Pt ratio, surfactant and reaction temperature on the morphology. In addition, we explored the formation process of hollow dendritic Ag/Pt nanoparticles by tracking the morphologies of the nanostructures formed at different stages. In order to improve the electrocatalytic property, we controlled the size of the nanoparticles and the thickness of the shell by adjusting the amount of the precursor. We found that these Ag/Pt alloy nanoparticles exhibited high activity (440 mA mg-1) and stability as an electrocatalyst for catalyzing methanol oxidation.

Colorimetric Detection of Ascorbic Acid Based on the Trigger of Gold Nanoparticles Aggregation by Cr(III) Reduced from Cr(VI).

Au nanoparticles (AuNPs) dispersed in water were stabilized by tripolyphosphate (P3O105-). When Cr2O72- (Cr(VI)) was present, the AuNPs did not change; when Cr3+ (Cr(III)) was present, the AuNPs would aggregate because of cooperative metal-ligand reaction. Aggregated AuNPs showed different color from the non-aggregated ones. Thus, a simple colorimetric assay was made using AuNPs-Cr(VI) to detect ascorbic acid (AA). Upon introducing AA to the AuNPs-Cr(VI) system, Cr(VI) was reduced to Cr(III), and the aggregation of AuNPs occurred. This colorimetric assay performed high selectivity and a linear concentration response in the range of 0.2 to 10 µM; its limit of detection was 0.15 µM.

Graphene oxide/ferroferric oxide/polyethylenimine nanocomposites for Congo red adsorption from water.

Graphene oxide/ferroferric oxide/polyethylenimine (GO/Fe3O4/PEI) nanocomposites were synthesized by an in situ growth of Fe3O4 nanoparticles on GO sheets, and then modified by PEI. The GO/Fe3O4/PEI nanocomposites showed extremely high removal efficiency for anionic dye Congo Red (CR) due to the positively charged PEI molecules (methylene blue was also tested but with low adsorption capacity due to its cationic property). The CR removal capacity was 574.7 mg g-1, higher than most of reported results. The adsorption kinetics could be well described by a pseudo-second-order model. Furthermore, GO/Fe3O4/PEI nanocomposites could be easily recycled by magnetic separation. The removal efficiency remained above 70% after five cycles.

[Macrobenthos community structure of macrobenthos and bioassessment of water quality in main stream of Songhua River].

An investigation was conducted on the community structure of macrozoobenthos in the main stream of Songhua River in spring (April and May), summer (July and August), and autumn (from September to November), and the water quality of the main stream was assessed with biotic indices. A total of 116 species of macrobenthos were collected, belonging to 36 families and 16 orders, among which, aquatic insects had the largest number, with 74 species (63.8% of the total) belonging to 21 families and 6 orders. The annual average density and biomass of the macrobenthos were 66.80 ind x m(-2) and 24.30 g x m(-2), respectively. The average density was the highest (90.52 ind x m(-2)) in spring, followed by in autumn (61.26 ind x m(-2)), and in summer (48.63 ind x m(-2)), while the average biomass was the highest (35.35 g x m(-2)) in autumn, followed by in summer (23.12 g x m(-2)), and in spring (14.41 g x m(-2)). The Shannon index, Pielou index, and Simpson index were the highest in spring, and were nearly the same in summer and autumn. Few species inhabited in the same types of microhabitats in all river sections. The species similarity in all sections was lower, with the largest similarity being only 60%. The species quantity of each functional feeding group was near, with 26 shredders, 32 collectors, 28 scrapers, and 30 predators. The water quality assessed with biotic index (BI) and family biotic index (FBI) was basically coincident with each other, and was accordant with chemical monitoring. The water quality above the Harbin Section of Songhua River was fair, and that below the Harbin Section was contaminated or seriously contaminated. It was presumed that the macrobenthos species composition and community structure had been affected due to the building of ship-electricity hinge in Dadingzi Mountain.

Hydrodechlorination of chlorobenzene over polymer-stabilized palladium-platinum bimetallic colloidal nanocatalysts.

Poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized Pd, Pt, Pd-Pt nanocatalysts were prepared and characterized by transmission electron microscopy (TEM). Hydrogenation of chlorobenzene was carried out over these colloidal nanocatalysts under ambient conditions. The catalytic properties for the hydrogenation of chlorobenzene depended on the composition of the bimetallic nanocatalysts. The conversion of chlorobenzene over PVP-Pd (83.64%) was higher than that of PVP-Pt (66.67%), which indicated that the activity of Pd was higher than that of Pt. In 10 hrs. the conversions of all the bimetallic nanocatalysts were higher than that of PVP-Pt (66.67%) monometallic nanocatalysts, and the maximum conversion of chlorobenzene (95.34%) was achieved using PVP-Pd/Pt = 1/1 catalytic system, which was much higher than that of the physical mixture of monometallic nanocatalysts (PVP-Pd and PVP-Pt) at the same Pd/Pt ratio as the PVP-Pd/Pt bimetallic nanocatalysts used. The selectivity to benzene and cyclohexane of the bimetallic nanocatalysts (with < or = 40 mol% Pt) was similar to that of PVP-Pd monometallic nanocatalysts, and nearly approximately 100% selectivity to benzene could be obtained, the selectivity to cyclohexane increased slowly with increasing of platinum content in bimetallic nanocatalysts.