Interactions between gold nanoparticles with different morphologies and human serum albumin.

Introduction: Three different shapes of gold nanoparticles were synthesized in this experiment. At the same time, studies compared their effects with human serum albumin (HSA). Methods: Gold nanoparticles (AuNPs) with three different morphologies, such as, nanospheres (AuNSs), nanorods (AuNRs), and nanoflowers (AuNFs) were synthesized via a seeding method and their characteristic absorption peaks were detected using ultraviolet-visible (UV-vis) absorption spectroscopy, Telectron microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta potential measurements, circular dichroism (CD), and Fourier transform infrared spectroscopy (FTIR) to study the interactions between them and HSA. By comparing the thermodynamic parameters and quenching mechanism of the three materials, similarities and differences were determined in their interactions with HSA. Results: The results showed that with an increase in the concentration of the AuNPs with the three different morphologies, the UV-vis absorption peak intensity of the mixed solution increased, but its fluorescence intensity was quenched. This indicates that the three types of AuNPs interact with HSA, and that the interactions between them represent a static quenching process, which is consistent with the conclusions derived from three-dimensional fluorescence experiments. Through variable-temperature fluorescence experiments, the binding constants, number of binding sites, and thermodynamic parameters of the interactions between the three types of AuNPs and HSA were determined. The Gibbs free energy changes were <0, indicating that the reactions of the three types of AuNPs with HSA are spontaneous, resulting in associated matter. Binding constant measurements indicated that the strongest binding took place between the AuNFs and HSA. In addition, the results of fluorescence, CD spectroscopy, and FTIR showed that three different shapes of AuNPs can induce conformational changes in HSA and reduce the α-helix content. Among them, AuNFs have the smallest ability to induce conformational changes. Discussion: According to studies, AuNFs interact more favorably with HSA. This can be used as a reference for the administration of drugs containing AuNPs.

Facilitated remediation of heavy metals contaminated land using Quercus spp. with different strategies: Variations in amendments and experiment periods.

Phytoremediation using trees combined with soil amendments has gained much attention for its highly cost-effective trait. In natural field conditions, however, the results may not reflect the true performance of amendments based on short-term laboratory studies. In this three-year field trial, various soil amendments such as rice straw biochar, palygorskite, a combined biochar of rice straw biochar and palygorskite, and hydroxyapatite were used to systematically study the potential of the low-accumulator (Quercus fabri Hance) and high-accumulator (Quercus texana Buckley) for cadmium (Cd) and zinc (Zn) to remediate severely contaminated soils. Soil amendments enhanced the dendroremediation capacity of Quercus as the growth period prolonged. In 2021, the rice straw biochar treatment increased Cd and Zn accumulation by 1.76 and 2.09 times in Q. fabri, respectively, compared to the control. Cd and Zn accumulation increased to 1.78 and 2.10 times, respectively, under combined biochar treatment for Q. texana compared to the control. Metals accumulation was mainly enhanced by soil amendments through increasing the growth biomass of Q. fabri and improving the biomass and bioconcentration ability of Q. texana. Overall, soil amendments effectively improved the phytoremediation efficiency of Quercus in the long term, and selecting suitable amendments should be fully considered in phytoremediation.

Differences in Soil Microbial Communities between Healthy and Diseased Lycium barbarum cv. Ningqi-5 Plants with Root Rot.

For a long time, the development of the Lycium barbarum industry has been seriously restricted by root rot disease. In general, the occurrence of plant root rot is considered to be closely related to the composition and diversity of the soil microbial community. It is critical to understand the relationship between the occurrence of root rot in L. barbarum and the soil microbial composition. In this study, samples of the rhizosphere, rhizoplane, and root zone were collected from diseased and healthy plants. The V3-V4 region of bacterial 16S rDNA and the fungal ITS1 fragment of the collected samples were sequenced using Illumina MiSeq high-throughput sequencing technology. The sequencing results were first quality controlled and then aligned with the relevant databases for annotation and analysis. The richness of fungal communities in the rhizoplane and root zone of the healthy plants was significantly higher than that of the diseased plants (p < 0.05), and the community evenness and diversity of all the rhizoplane samples were significantly different from those of the rhizosphere and root zone. The richness of the bacterial communities in the rhizosphere and root zone of healthy plants was significantly greater than those of diseased plants (p < 0.05). The community composition of the rhizoplane was quite different from the other parts. The abundance of Fusarium in the rhizoplane and rhizosphere soil of diseased plants was higher than that in the corresponding parts of healthy plants. The abundances of Mortierella and Ilyonectria in the three parts of the healthy plants were correspondingly higher than those in the three parts of the diseased plants, and Plectosphaerella was the most abundant in the rhizoplane of diseased plants. There was little difference in the composition of the dominant bacteria at the phylum and genus levels between healthy plants and diseased plants, but the abundances of these dominant bacteria were different between healthy and diseased plants. Functional prediction showed that the bacterial community had the largest proportion of functional abundance belonging to metabolism. The functional abundances of the diseased plants, such as metabolism and genetic information processing, were lower than those of the healthy plants. The fungal community function prediction showed that the Animal Pathogen-Endophyte-Lichen Parasite-Plant Pathogen-Soil Saprotroph-Wood Saprotroph group had the largest functional abundance, and the corresponding fungi were Fusarium. In this study, we mainly discussed the differences in the soil microbial communities and their functions between the healthy and diseased L. barbarum cv. Ningqi-5, and predicted the functional composition of the microbial community, which is of great significance to understanding the root rot of L. barbarum.

Responses of soil seed banks to drought on a global scale.

The global increase in drought frequency and intensity in large areas has potentially important effects on soil seed banks (SSBs). However, a systematic evaluation of the impact of drought on SSBs at a global scale has not yet been well understood. We evaluated the effects of drought on SSBs and identified the association key drivers in the current meta-analysis. The overall effects of drought on soil seed density and richness were weak negative and positive, respectively. Drought significantly increased soil seed density by 11.94 % in forest ecosystem, whereas soil seed richness were significantly increased in vascular plants (7.39 %). Linear mixed-effect results showed that soil seed density and richness significantly reduced as increasing drought intensity. In addition, geography (altitude) has significance in controlling the lnRR of soil seed density by altering climate (mean annual precipitation, drought) and soil properties (pH, soil organic carbon, and clay content) in the structural equation model, whereas soil seed richness was controlled by geography (altitude, and latitude) via climate (mean annual precipitation). In summary, the results suggested the size of SSBs response to drought and its relationship with drought intensity in terrestrial ecosystems, it may shed light on ecosystem restoration, succession, and management using SSBs when estimating the future drought.

Hollow CoS/C Structures for High-Performance Li, Na, K Ion Batteries.

Alkali ion (Li, Na, and K) batteries as a new generation of energy storage devices are widely applied in portable electronic devices and large-scale energy storage equipment. The recent focus has been devoted to develop universal anodes for these alkali ion batteries with superior performance. Transition metal sulfides can accommodate alkaline ions with large radius to travel freely between layers due to its large interlayer spacing. Moreover, the composite with carbon material can further improve electrical conductivity of transition metal sulfides and reduce the electron transfer resistance, which is beneficial for the transport of alkali ions. Herein, we designed zeolitic imidazolate framework (ZIF)-derived hollow structures CoS/C for excellent alkali ion (Li, Na, and K) battery anodes. The porous carbon framework can improve the conductivity and effectively buffer the stress-induced structural damage. The ZIF-derived CoS/C anodes maintain a reversible capacity of 648.9, and 373.2, 224.8 mAh g-1 for Li, Na, and K ion batteries after 100 cycles, respectively. Its outstanding electrochemical performance is considered as a universal anode material for Li, Na, and K ion batteries.

The chloroplast genome of Amygdalus L. (Rosaceae) reveals the phylogenetic relationship and divergence time.

BACKGROUND: Limited access to genetic information has greatly hindered our understanding of the molecular evolution, phylogeny, and differentiation time of subg. Amygdalus. This study reported complete chloroplast (cp) genome sequences of subg. Amygdalus, which further enriched the available valuable resources of complete cp genomes of higher plants and deepened our understanding of the divergence time and phylogenetic relationships of subg. Amygdalus. RESULTS: The results showed that subg. Amygdalus species exhibited a tetrad structure with sizes ranging from 157,736 bp (P. kansuensis) to 158,971 bp (P. davidiana), a pair of inverted repeat regions (IRa/IRb) that ranged from 26,137-26,467 bp, a large single-copy region that ranged from 85,757-86,608 bp, and a small single-copy region that ranged from 19,020-19,133 bp. The average GC content of the complete cp genomes in the 12 species was 36.80%. We found that the structure of the subg. Amygdalus complete cp genomes was highly conserved, and the 12 subg. Amygdalus species had an rps19 pseudogene. There was not rearrangement of the complete cp genome in the 12 subg. Amygdalus species. All 12 subg. Amygdalus species clustered into one clade based on both Bayesian inference and maximum likelihood. The divergence time analyses based on the complete cp genome sequences showed that subg. Amygdalus species diverged approximately 15.65 Mya. CONCLUSION: Our results provide data on the genomic structure of subg. Amygdalus and elucidates their phylogenetic relationships and divergence time.

[Potential geographical distribution and changes of Artemisia ordosica in China under future climate change]. / 未来气候变化下黑沙蒿在中国的潜在地理分布及变迁.

Artemisia ordosica is a forerunner species of wind-break and sand-fixation in desert steppe in China, which plays an important role in ecosystem restoration and reconstruction. How-ever, it could influence human health. Based on 89 valid data of current distribution of A. ordosica in China and 19 typical climatic factors, the MaxEnt model was used to simulate the potential distribution of A. ordosica in China under current and two scenarios (RCP 4.5 and RCP 8.5; 2050s and 2070s). The SDM toolbox of ArcGIS software was used to analyze the potential distribution range of A. ordosica and its changes in China. The importance of key climatic factors was evaluated by comprehensive contribution rate, Jackknife method, and response curve of environmental variables. The accuracy of model was tested and evaluated by area under the curve (AUC) of the test subject working characteristic (ROC). The results showed that the MaxEnt model worked well (AUC=0.980). which predicted that A. ordosica was mainly concentrated in and around Mu Us Sandy Land, consistent with the current actual distribution range. The distribution area of A. ordosica of potential high fitness under the future two scenarios decreased by 5.2%-26.8%, which was negatively affected by future climate change. Seasonal variation of temperature, mean precipitation in the coldest season, and mean annual temperature had the greatest impact. The core area of future potential distribution of A. ordosica in China was located in Mu Us Sandy Land, with a tendency for spreading to northeast (Jilin, Heilongjiang, Liaoning and some parts of Hebei).

Studies on binding of single-stranded DNA with reduced graphene oxide-silver nanocomposites.

The binding reaction of reduced graphene oxide-silver nanocomposites (rGO-AgNCs) with calf thymus single-stranded DNA (ssDNA) was studied by ultraviolet-visible absorption, fluorescence spectroscopy and circular dichroism (CD), using berberine hemisulphate (BR) dye as a fluorescence probe. The absorbance of ssDNA increases, but the fluorescence intensity is quenched with the addition of rGO-AgNCs. The binding of rGO-AgNCs with ssDNA was able to increase the quenching effects of BR and ssDNA, and induce the changes in CD spectra. All of the evidence indicated that there was a relatively strong interaction between ssDNA and rGO-AgNCs. The data obtained from fluorescence experiments revealed that the quenching process of ssDNA caused by rGO-AgNCs is primarily due to complex formation, i.e. static quenching. The increasing trend of the binding equilibrium constant (Ka) with rising temperature indicated that the binding process was an endothermic reaction. The calculated thermodynamic parameters showed that the binding process was thermodynamically spontaneous, and hydrophobic association played predominant roles in the binding of ssDNA to the surface of rGO-AgNCs.

Complete chloroplast genome sequence of the Amygdalus Nana.

Amygdalus nana is the research materials, and we used the Illumina HiSeq X Ten system to do sequencing, and used the complete chloroplast genomes of 12 species to constructed thephylogenetic tree. The results showed that the complete chloroplast genome of the A. nana was 158,596 bp in length, containing a largen single copy (LSC) region of 86,608 bp, a small single copy (SSC) region of 18,998 bp, and a pair of inverted repeats (IRs) region of 26,411 bp. The genome has a GC content of 36.7%. The LSC, SSC, and IR regions represent 54.61, 11.98, and 33.31% of the A. nana chloroplast genome length respectively. We annotated 130 genes, including 85 protein coding genes, 8 rRNA genes, and 37 tRNA genes. And the phylogenetic analysis suggested that the A. nana is closely related to A. mongolica.

The complete chloroplast genome of the Amygdalus ferganensis (Rosaceae) in Xinjiang, China.

Amygdalus ferganensis is a member of the family Rosaceae. In this paper, we report complete chloroplast genome sequences of A. ferganensis (Rosaceae). The results showed that A. ferganensis complete chloroplast genome comprises 158,365 bp, containing a largen single copy (LSC) region of 86,240 bp, a small single copy (SSC) region of 19,012 bp, and a pair of inverted repeats (IRs) region of 26,386 bp. The genome has a GC content of 42.6%. The LSC, SSC, and IR regions represent 54.46, 12.01, and 33.32% of the A. ferganensis chloroplast genome length. We annotated 112 genes, including 78 protein coding genes, 4 rRNAs, and 30 tRNAs. And A. ferganensis is closely the A. persica.

Study on the interaction of graphene oxide­silver nanocomposites with bovine serum albumin and the formation of nanoparticle-protein corona.

The interaction between graphene oxide-sliver nanocomposites (GO-AgNCPs) and bovine serum albumin (BSA) in aqueous buffer solution was investigated by using several spectroscopic and imaging techniques. The visible absorbance intensity of GO-AgNCPs increased with increasing concentrations of BSA, and a slight redshift of the surface plasmon resonance band (SPR) occurred due to the absorption of BSA on the surface of GO-AgNCPs. Fluorescence data revealed a static quenching process of BSA caused by GO-AgNCPs. Thermodynamic parameters of the absorption process, including adsorption equilibrium constants, changes in Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS), were evaluated at different temperatures. Negative values of ΔG showed that this process was spontaneous and the BSA-GO-AgNCPs complex might form in aqueous solution. Negative values of ΔH and ΔS suggested that the binding was mainly an enthalpy-driven process, and van der Waals forces and hydrogen bonding were the major force in the formation of the nanoparticle-protein corona. Analysis of synchronous, three dimensional (3D) fluorescence and circular dichroism (CD) spectra demonstrated that the conformation of BSA was slightly altered in the presence of GO-AgNCPs. The protein corona formed on the surface of GO-AgNCPs was directly observed by scanning probe microscopy (SPM).

Synthesis of triangular silver nanoprisms and spectroscopic analysis on the interaction with bovine serum albumin.

The interactions of triangular silver nanoprisms (TAgNPrs) with bovine serum albumin (BSA) were investigated using multiple spectroscopic techniques. A noticeable absorbance increase was noted in the peak ranges of 250 to 300 nm for BSA, and the intensity increased with the increasing concentration of TAgNPrs. Furthermore, a slight blue shift of the surface plasmon resonance band of TAgNPrs occurred, indicating that the protein absorbed on the TAgNPrs surface to form a bio-nano interface. Analysis of fluorescence quenching data using the Stern-Volmer method revealed that static quenching takes place with complex formation. Evaluation of thermodynamic parameter ΔG θ for the binding processes indicated that the binding reaction was exothermic. Furthermore, the values of binding constant K revealed that the size of nanoparticles can affect the binding degree. The order of binding affinity is 43.7 nm > 36.2 nm > 25.1 nm. The competitive experiments of site markers (flufenamic acid and phenylbutazone) suggested that the binding site of TAgNPrs on BSA was located in the region of subdomain IIIA (Sudlow site II). In addition, the conformational changes of BSA by TAgNPrs were analyzed by using synchronous fluorescence spectra, circular dichroism, and three-dimensional fluorescence spectra. Graphical abstract The protein absorbed on the TAgNPrs surface to form a nanoparticle-protein corona.

Kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate/n-decane microemulsions.

In this work, we studied the kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/n-decane microemulsions with the molar ratios of water to AOT being 35.0 and 40.8 via the microcalorimetry at various temperatures. It was found that the Arrhenius equation was valid for correlating experimental measurements in the noncritical region, but the slowing down effect existed significantly in the near critical region. We determined the values of the critical slowing down exponent and found it to be 0.187 ± 0.023 and 0.193 ± 0.032, respectively, which agreed well with the theoretical value of 0.207 predicted by the Griffiths-Wheeler rule for the singularity of the dimer/monomer droplet equilibrium in the critical AOT/water/n-decane microemulsions.

Critical anomalies of alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water.

We have used three-wavelength UV-spectrophotometry to study the reaction of the alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water. It was found that when the temperature was far away from the critical point, the values of the natural logarithm of the rate constant k and the natural logarithm of the chemical equilibrium K determined in our experiments had good linear relationships with the reciprocal of temperature, which served as the backgrounds and were used for correcting k and K in the critical region. The critical slowing down of the reaction and the critical anomaly of the chemical equilibrium were detected near the critical point. The value of the critical exponent characterizing the slowing down effect of the reaction rate was obtained to be 0.156, which was close to the value 0.11 associated with the heat capacity divergence and agreed with the theoretical prediction. The experimental result also confirmed the theoretical prediction of 0.11 for the critical exponent characterizing the weak divergence of the singularity of the chemical equilibrium.

Kinetics of the reaction of crystal violet with hydroxide ion in the critical solution of 2-butoxyethanol + water.

The kinetics of alkaline fading of crystal violet (CV) has been studied by UV spectrophotometry and microcalorimetry in the critical binary solution of 2-butoxyethanol + water at the initial reaction stage and various temperatures. It was found that the first-order rate constants obtained from these two methods are well accorded with each other, and the temperature dependence of the rate constant obeyed the Arrhenius equation in a temperature region far from the critical point. The critical slowing down was detected by both methods near the critical point. A simple empirical crossover model was proposed and used to analyze the experimental data to obtain the critical exponents, which were 0.158 ± 0.013 and 0.133 ± 0.012 from UV spectrophotometry and microcalorimetry, respectively, and the former was in good agreement with the theoretical prediction of 0.151. The slight lower value derived from microcalorimetry was attributed to the stirring in the microcalorimeter, which weakened the critical reduction of the diffusion coefficient.