Epiberberine regulates lipid synthesis through SHP (NR0B2) to improve non-alcoholic steatohepatitis.

Epiberberine (EPI), extracted from Rhizome Coptidis, has been shown to attenuate hyperlipidemia in vivo. Herein we have studied the mechanism by which EPI is active against non-alcoholic steatohepatitis (NASH) using, mice fed on a methionine- and choline-deficient (MCD) diet and HepG2 cells exposed to free fatty acids (FFA). We show that small heterodimer partner (SHP) protein is key in the regulation of lipid synthesis. In HepG2 cells and in the livers of MCD-fed mice, EPI elevated SHP levels, and this was accompanied by a reduction in sterol regulatory element-binding protein-1c (SREBP-1c) and FASN. Therefore, EPI reduced triglyceride (TG) accumulation in steatotic hepatocytes, even in HepG2 cells treated with siRNA-SHP, and also improved microbiota. Thus, EPI suppresses hepatic TG synthesis and ameliorates liver steatosis by upregulating SHP and inhibiting the SREBP1/FASN pathway, and improves gut microbiome.

A new species of Cicadocoris (Hemiptera, Coleorrhyncha, Progonocimicidae) from the Middle Jurassic of the Jiyuan Basin, China.

Progonocimicids are one of key representatives from the Middle-Late Jurassic Daohugou biota, the early assemblage of the Yanliao biota. Here we describe a new progonocimicid species, Cicadocoris henanensis sp. nov., from the Middle Jurassic Jiyuan Basin in central China. This not only represents a novel case indicating the abundance of progonocimicids during the Jurassic but also provides additional evidence substantiating the stratigraphic correlation between the Yangshuzhuang Formation in the Jiyuan Basin and the Haifanggou Formation in the Yanliao Region.

New stem-anisopteran dragonflies in the Jurassic of China (Odonata: Epiproctophora).

The odonatan asiopterid Turanopteron sinensis sp. nov. and the juragomphid Oxfordgomphus trescellulae gen. et sp. nov. are described on the basis of two new fossil wings from the Middle-Upper Jurassic of Henan Province in China. These taxa belong to ancient, Toarcian epiproctophoran stem groups of Anisoptera Selys, 1854. They show important affinities with taxa from the Karatau entomofauna in Kazakhstan. These groups progressively decrease and were replaced by more modern clades of Anisoptera during the Late Jurassic.

Combined therapy with early initiation of infliximab following drainage of perianal fistulising Crohn's disease: a retrospective cohort study.

BACKGROUND: Recent studies have confirmed that combined surgery and anti-TNF therapy could improve outcomes in patients with perianal fistulising Crohn's disease (PFCD). However, the optimal timing for infliximab infusion after surgical intervention is uncertain. We aimed to determine the long-term efficacy of early initiation of infliximab following surgery among PFCD patients. METHODS: We performed a retrospective cohort study of PFCD patients who received combined infliximab and surgical treatment between 2010 and 2018 at a tertiary referral hospital. Patients were grouped according to the time interval between surgery and infliximab infusion, with < 6 weeks into early infliximab induction group and > 6 weeks into delayed infliximab induction group. The primary outcome was to compare surgical re-intervention between early and delayed infliximab induction groups. The secondary outcomes were fistula healing and predictors associated with these outcomes of early infliximab induction approach. RESULTS: One hundred and seventeen patients were included (73 in early infliximab induction, 44 in delayed infliximab induction). The median interval between surgery and infliximab initiation was 9.0 (IQR 5.5-17.0) days in early infliximab induction group and 188.0 (IQR 102.25-455.75) days in delayed infliximab induction group. After followed-up for a median of 36 months, 61.6% of patients in early infliximab induction group and 65.9% in delayed infliximab induction group attained fistula healing (p = 0.643). The cumulative re-intervention rate was 23%, 32%, 34% in early infliximab induction group and 16%, 25%, 25% in delayed infliximab induction group, at 1, 2, and 3 years respectively (p = 0.235). Presence of abscess at baseline (HR = 5.283; 95% CI, 1.61-17.335; p = 0.006) and infliximab maintenance therapy > 3 infusions (HR = 3.691; 95% CI, 1.233-11.051; p = 0.02) were associated with re-intervention in early infliximab induction group. Presence of abscess at baseline also negatively influenced fistula healing (HR = 3.429, 95% CI, 1.216-9.668; p = 0.02). CONCLUSION: Although no clear benefit was shown compared with delayed infliximab induction group, early initiation of infliximab after surgery could achieve promising results for PFCD patients. Before infliximab infusion, durable drainage is required for patients with concomitant abscess or prolonged infliximab maintenance therapy.

Integrating network pharmacology deciphers the action mechanism of Zuojin capsule in suppressing colorectal cancer.

BACKGROUND AND PURPOSE: Zuojin capsule (ZJC), a classical prescription, is outstanding in improving the conditions of patients with gastrointestinal diseases and colorectal cancer (CRC). Although ZJC has multi-ingredient and multi-target characteristics, its pharmacological effect on colorectal cancer and the underlying mechanism remain unclear. METHOD: Here, the activity of ZJC against CRC was evaluated by the experiments with CRC cells and HCT-116 xenografted mice. The key genes of CRC were obtained from the cancer genome atlas (TCGA). The genes potentially targeted by ZJC were collected from traditional Chinese medicine systems pharmacology (TCMSP) database. The underlying pathways related to selected targets were analyzed through gene ontology (GO) and pathway enrichment analyses. Western blot (WB), cellular thermal shift assay (CETSA), molecular docking and quantitative real-time PCR (QRT-PCR) were carried out to confirm the validity of the targets. RESULTS: In vitro and in vivo results indicated that ZJC may inhibit CRC cells and tumor growth. The network pharmacological analysis indicated that 22 compounds, 51 targets and 20 pathways were involved in the compound-target-pathway network. Our results confirmed that ZJC inhibited cycle progression, migration and induced apoptosis by targeting candidate genes (CDKN1A, Bcl2, E2F1, PRKCB, MYC, CDK2, and MMP9). We found that ZJC could directly change the protein level by regulating the protein stability and transcriptional activity of the target. CONCLUSIONS: In summary, combined network pharmacology and biological experiments proved that the main ingredients of ZJC such as quercetin, (R)-Canadine, palmatine, rutaecarpine, evodiamine, beta-sitosterol and berberine can target CDKN1A, Bcl2, E2F1, PRKCB, MYC, CDK2 and MMP9 to combat colorectal cancer. The results of this study provide a basic theory for the clinical trials of Zuojin Capsules against colorectal cancer.

Application Value and Research Progress of Human Microbiome in Sexual Assault Cases.

In recent years, sexual assault cases have been on the rise, seriously infringing the legitimate rights and interests of women and children, causing widespread concern in society. DNA evidence has become the key evidence to prove the facts in sexual assault cases, but lack of DNA evidence or only DNA evidence in some sexual assault cases leads to unclear facts and insufficient evidence. With the emergence of high-throughput sequencing technology and the development of bioinformatics and artificial intelligence, new progress has been made in the study of human microbiome. Researchers have begun to use human microbiome for difficult sexual assault cases indentification. This paper reviews the characteristics of human microbiome, and its application value in the inferences of the body fluid stain origin, the sexual assault method, the crime time, etc. In addition, the challenges faced by the application of the human microbiome in practical case handling, the solutions and future development potential are analyzed and prospected.

[Effects of Copper Pollution on Microbial Communities in Wheat Root Systems].

Wheat is the main food crop in China while at the same time, heavy metals pose a significant threat to crop growth and food security. Many studies indicate that rhizospheric microorganism play an important role in regulating crop development and stress resistance. In this study, the variation in wheat root-associated microbial communities under copper pollution was studied using high-throughput sequencing. The microbial community structure and diversity among different wheat rhizocompartments were compared after sequencing of microbial communities in the bulk soil, rhizosphere, and endosphere of wheat under copper pollution in combination with pot-based experiments. The results showed that the microbial diversity of the endosphere was significantly lower than in the rhizosphere and bulk soil(P<0.001), indicating that root surfaces serve as a gateway for microorganisms to enter into the interior root environment, and play a role in filtering root colonization. Copper pollution significantly reduced the microbial diversity of the rhizosphere (P<0.05). In the bulk soil and endosphere environments, although copper pollution reduced microbial diversity in the corresponding rhizocompartment, the difference was not significant (P>0.05). Proteobacteria and Actinobacteria were the dominant bacteria groups in the rhizosphere and the bulk soil under copper pollution. In addition, microbes such as Bacillus, Pseudoxanthomonas, and Sphingomonas show strong stress resistance and can provide nutrients for plants.

ANALYSIS OF THE CLINICAL CHARACTERISTICS OF PERIANAL FISTULISING CROHN'S DISEASE IN A SINGLE CENTER.

BACKGROUND: Clinical characteristics are keys to improve identification and treatment of Crohn´s disease (CD) so that large sample analysis is of great value. AIM: To explore the clinical characteristics of perianal fistulising CD. METHODS: Analysis of 139 cases focused on their clinical data. RESULTS: The proportion of males and females is 3.3:1; the mean age is 28.2 years; 47.5% of patients had anal fistula before CD diagnosis. Patients with prior perianal surgery and medication accounted for 64.7% and 74.1% respectively. The L3 type of lesion was present in 49.6% and the B1 and B2 types for 51.8% and 48.2% respectively; complex anal fistula was diagnosed in 90.6%. Symptoms of diarrhea were found in 46% and perianal lesions alone in 29.5% of patients. Abnormal BMI values was present in 44.6%; active CD activity index in 64.7%; and 94.2% had active perianal disease activity index. A proportion of patients manifest abnormal C-reactive protein, erythrocyte sedimentation rate, platelet, hemoglobin and albumin. CONCLUSION: We suggest that patients with anal fistula associated to these clinical features should alert the medical team to the possibility of CD, which should be further investigated through endoscopy and imaging examination of alimentary tract to avoid the damage of anal function by routine anal fistula surgery.

Turn on fluorescent detection for Cd2+ based on surfactant controlled squaraine aggregation.

A thymine moiety as ion binding accepter was introduced into asymmetric squaraine fluorophore by amide coupling reaction to develop a new thymine-squaraine based fluorescent chemosensor (SQ). Its detection ability towards heavy metal ions was investigated by UV-vis and fluorescent spectrometry. The results showed that the sensor had high selectivity towards Cd2+ over the other metal ions in aqueous media. Moreover, it was shown that the turn on fluorescence signal occurred in the present of high concentration of cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) solution which resulting in deaggregations of SQ. The stoichiometric ratio was determined by Job's plot analysis as 1:1 and the binding constant as 2.03 × 103 M-1 for the complex between Cd2+ and SQ was further calculated by the Benesi-Hilderbrand plot. The complexation mechanism was proposed according to ESI-MS and NMR results. The following DFT calculation fully supported that the detailed coordination mode of Cd2+ and SQ went through six-membered carbonyl oxygen and the CO group in the amide chain. Finally, the SQ sensor was successfully applied in waste water sample analysis.

Analysis of the clinical characteristics of perianal fistulising crohn's disease in a single center / Análise das características clínicas da doença de crohn fistulizante perianal em um único centro

ABSTRACT Background: Clinical characteristics are keys to improve identification and treatment of Crohn´s disease (CD) so that large sample analysis is of great value. Aim: To explore the clinical characteristics of perianal fistulising CD. Methods: Analysis of 139 cases focused on their clinical data. Results: The proportion of males and females is 3.3:1; the mean age is 28.2 years; 47.5% of patients had anal fistula before CD diagnosis. Patients with prior perianal surgery and medication accounted for 64.7% and 74.1% respectively. The L3 type of lesion was present in 49.6% and the B1 and B2 types for 51.8% and 48.2% respectively; complex anal fistula was diagnosed in 90.6%. Symptoms of diarrhea were found in 46% and perianal lesions alone in 29.5% of patients. Abnormal BMI values was present in 44.6%; active CD activity index in 64.7%; and 94.2% had active perianal disease activity index. A proportion of patients manifest abnormal C-reactive protein, erythrocyte sedimentation rate, platelet, hemoglobin and albumin. Conclusion: We suggest that patients with anal fistula associated to these clinical features should alert the medical team to the possibility of CD, which should be further investigated through endoscopy and imaging examination of alimentary tract to avoid the damage of anal function by routine anal fistula surgery.

RESUMO Racional: As características clínicas são fundamentais para melhorar a identificação e o tratamento da doença de Crohn (DC), de modo que a análise da amostra seja de grande valor. Objetivo: Explorar as características clínicas da DC fistulizante perianal. Métodos: Análise de 139 casos focados em seus dados clínicos. Resultados: A proporção de homens e mulheres foi de 3,3: 1; a média de idade de 28,2 anos; 47,5% dos pacientes tiveram fístula anal antes do diagnóstico de DC. Pacientes com cirurgia perianal prévia e medicação representaram 64,7% e 74,1%, respectivamente. O tipo de lesão L3 estava presente em 49,6% e os tipos B1 e B2, em 51,8% e 48,2%, respectivamente; fístula anal complexa foi diagnosticada em 90,6%. Sintomas de diarréia foram encontrados em 46% e lesões perianais isoladas em 29,5% dos pacientes. Valores anormais de IMC estavam presentes em 44,6%; índice de atividade DC ativa em 64,7%; e 94,2% tinham índice de atividade de doença perianal ativo. Proporção significativa de pacientes tinha proteína-C reativa, taxa de sedimenta do eritrócito, plaquetas hemoglobina e albumina anormais. Conclusão: Sugere-se que pacientes com fístula anal associada às essas características clínicas alertem a equipe médica para a possibilidade de DC, que deve ser investigada por endoscopia e exame de imagem do trato digestivo para evitar dano na função anal pela operação que rotineiramente é realizada no tratamento da fístula anal.

Dual Sensing Performance of 1,2-Squaraine for the Colorimetric Detection of Fe3+ and Hg2+ Ions.

A simple 1,2-squaraine based chemosensor material (SQ) has been reported to show dual sensing performance for colorimetric detection of Fe3+ and Hg2+ ions. Compared to common instrumental analysis, this method could provide fast and direct detection though colorimetric changes by the naked eye. The sensor has shown excellent selectivity over the other metal ions by tuning different solvent environments. The detection limit for Fe3+ could reach to 0.538 µM, which was lower than that in the environmental agency guideline (U.S. Environmental Protection Agency, U.S. EPA) in drinking water. And for Hg2+ detection, the limit was calculated as 1.689 µM in our case. A 1:1 binding mode between SQ⁻Fe3+ and SQ⁻Hg2+ ion were evidenced by Job's plot measurement and IR analysis. The proposed different binding mechanisms were also supported by Density Function Theory (DFT) calculation. All these findings provide a unique material and a simple, facile, and low cost colorimetric method for dual metal ions analysis and have shown preliminary analytical applications in industrial water sample analysis.

Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-ß1 signaling in Crohn's disease intestinal fibrosis.

AIM: To explore the role and mechanism of total flavone of Abelmoschus manihot (TFA) on epithelial-mesenchymal transition (EMT) progress of Crohn's disease (CD) intestinal fibrosis. METHODS: First, CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial (IEC-6) cells and select the optimal concentrations of TFA for our further studies. Then cell morphology, wound healing and transwell assays were performed to examine the effect of TFA on morphology, migration and invasion of IEC-6 cells treated with TGF-ß1. In addition, immunofluorescence, real-time PCR analysis (qRT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress. Moreover, western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways. Further, the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by qRT-PCR, western blotting, morphology, wound healing and transwell assays. RESULTS: In this study, TFA promoted transforming growth factor-ß1 (TGF-ß1)-induced (IEC-6) morphological change, migration and invasion, and increased the expression of epithelial markers and reduced the levels of mesenchymal markers, along with the inactivation of Smad and MAPK signaling pathways. Moreover, we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-ß1-induced EMT in IEC-6 cells. Importantly, co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-ß1-induced EMT in IEC-6 cells than either one of them. CONCLUSION: These findings could provide new insight into the molecular mechanisms of TFA on TGF-ß1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis.

Specific colorimetric detection of Fe3+ ions in aqueous solution by squaraine-based chemosensor.

A new squaraine based chemosensor TSQ was developed for colorimetric detection of Fe3+ ions. A thymine moiety in TSQ was constructed to act as an ion acceptor. The sensor displayed an instant colorimetric response specific to Fe3+ over the other metal ions in 20% AcOH-H2O solution. The limit of detection was much lower than that of the environmental protection agency guideline (5.37 µM) in drinking water. A 1 : 1 binding between TSQ and Fe3+ ion was evidenced by Job's plot measurement, ESI-MS and Fourier transform infrared (IR) measurements. Moreover, the proposed sensing mechanism of the receptor towards Fe3+ was strongly supported by DFT calculation. Finally, the sensor has proven to be suitable in real sample applications.

Improving the sensitivity of immunoassay based on MBA-embedded Au@SiO2 nanoparticles and surface enhanced Raman spectroscopy.

Traditional "sandwich" structure immunoassay is mainly based on the self-assembly of "antibody on solid substrate-antigen-antibody with nanotags" architectures, and the sensitivity of this strategy is critically depended on the surface enhanced Raman scattering (SERS) activities and stability of nanotags. Therefore, the rational design and fabrication on the SERS nanotags attracts the common interests to the bio-related detecting and imaging. Herein, silica encapsulated Au with mercaptobenzoic acid (MBA) core-shell nanoparticles (Au-MBA@SiO2) are fabricated instead of the traditional naked Au or Ag nanoparticles for the SERS-based immunoassay on human and mouse IgG antigens. The MBA molecules facilitate the formation of continuous pinhole-free silica shell and are also used as SERS labels. The silica shell is employed to protect MBA labels and to isolate Au core from the ambient solution for blocking the aggregation. This shell also played the similar role to BSA in inhibiting the nonspecific bindings, which allowed the procedures for constructing "sandwich" structures to be simplified. All of these merits of the Au-MBA@SiO2 brought the high performance in the related immunoassay. Benefiting from the introduction of silica shell to encapsulate MBA labels, the detection sensitivity was improved by about 1-2 orders of magnitude by comparing with the traditional approach based on naked Au-MBA nanoparticles. This kind of label-embedded core-shell nanoparticles could be developed as the versatile nanotags for the bioanalysis and bioimaging.

Controlling dynamic SERS hot spots on a monolayer film of Fe3O4@Au nanoparticles by a magnetic field.

A large surface-enhanced Raman scattering (SERS) effect is critically dependent on the gap distance of adjacent nanostructures, i.e., "hot spots". However, the fabrication of dynamically controllable hot spots still remains a remarkable challenge. In the present study, we employed an external magnetic field to dynamically control the interparticle spacing of a two-dimensional monolayer film of Fe3O4@Au nanoparticles at a hexane/water interface. SERS measurements were performed to monitor the expansion and shrinkage of the nanoparticles gaps, which produced an obvious effect on SERS activities. The balance between the electrostatic repulsive force, surface tension, and magnetic attractive force allowed observation of the magnetic-field-responsive SERS effect. Upon introduction of an external magnetic field, a very weak SERS signal appeared initially, indicating weak enhancement due to a monolayer film with large interparticle spacing. The SERS intensity reached maximum after 5s and thereafter remained almost unchanged. The results indicated that the observed variations in SERS intensities were fully reversible after removal of the external magnetic field. The reduction of interparticle spacing in response to a magnetic field resulted in about one order of magnitude of SERS enhancement. The combined use of the monolayer film and external magnetic field could be developed as a strategy to construct hot spots both for practical application of SERS and theoretical simulation of enhancement mechanisms.

[Speciation and Risk Assessment of Heavy Metals in Surface Sediments from the Heavily Polluted Area of Xiaoqing River].

Th concentrations of Cu, As, Pb, Zn, Cr, Cd, Ni in interstitial water were analyzed by ICP-MS from the heavily polluted area of Xiaoqing River. A modified BCR's sequential extraction procedure was used to investigate the fraction of the heavy metals in the surface sediments. The aquatic toxicity of heavy metals in interstitial water was assessed by US Water Quality Criteria (CCC, CMC). Based on the speciation of the metals in the surface sediments, the ecological risk of heavy metals was assessed with methods of risk assessment code (RAC) and potential ecological risk index. The results showed that: The tested heavy metals would not pose chronic toxicity for aquatic ecosystem. The contents of heavy metals (Cu, Pb, Zn, Cr, Cd, Ni) in the surface sediments were higher than the background values of the local soils, indicating enrichment of heavy metals. Cu, As and Ni were mainly composed with residual fractions, Pb and Cr were mainly constituted of residual and oxidizable fractions, and mass fractions of Zn and Cd existed mainly in acid soluble and reducible factions. The contents of bio-available fractions of Cd, Zn, Cr and Pb in the sediments were higher those of residual fractions, indicating high potential for secondary release. Based on calculation of RAC method, Cu, Pb, Cr and As posed extremely low to low risk to the environment. Accordingly, Ni was of low to medium risk, Cd was of medium to high risk, and Zn was of medium to extremely high risk to the environment. The potential ecological risk of heavy metals in the sediments was in the descending order of Cd > Zn > Ni > As > Cu > Cr > Pb. Cd had high to very high potential ecological risk comparing with the other heavy metals. The potential ecological risk indexes (RI) of the heavy metals in the sediments were in the range of 136.83-264.83, and posed medium to high potential ecological risks for Xiaoqing River.

[Surface Enhanced Raman Spectroscopic Studies on the Coupling Effect of Multilayer Au@SiO2 Film].

The SiO2 shell with the thickness of 4 nm was attached onto high surface enhanced Raman spectroscopy (SERS) active Au core nanoparticles to obtain Au@SiO2 core shell nanoparticles by the hydrolysis of sodium silicate solution with the boiling water bath. The inert shell of SiO2 isolated the direct interaction of Au nanoparticles and probe molecules. The stable, compact and uniform monolayer nanoparticles film was self assembled at water/oil interface, and one to six monolayers film was transferred to Si wafer as SERS substrates through layer by layer technique. The relationship between the SERS activities and layers of the monolayer nanoparticles film on Si surface was investigated. The SERS mapping was developed to determine the layers of the Au@SiO2 film. The coupling effect among the Au@SiO2 films was explored by changing the adsorption location of the probe on the multilayer films. The result revealed that the monolayer film was a favourable candidate with high-quality performances for the SERS application. The SERS signal was distributed on the surface with high uniformity at the same monolayer film, and it was enhanced in the intensity with the increase in film layers. It reached the maximun intensity as the film was over five layers. It indicated that the SERS signal was contributed mainly by the first five monolayers. The probe molecules were immobilized onto the first monolayer nanoparticles film, and the SERS signal from the probe approached to the maximum as the second monolayer covered the probe modified first nanoparticles film. It was dominated by the coupling effect ("hot spots") of the adjacent layers. The SERS signal decreased in intensity when the third layer was transferred onto the second layer, and it disappeared after the fouth layer was covered, mainly duo to the shield of the nanoparticles film to the incident laser and Raman signal. The preliminary results provided guidance for fabricating optimal SERS substrates.

Inhibiting plasmon catalyzed conversion of para-nitrothiophenol on monolayer film of Au nanoparticles probed by surface enhanced Raman spectroscopy.

The plasmon catalyzed surface reaction has been attracted considerable attention due to its promising application in heterogeneous catalysis. This kind of plasmon catalysis played bilateral roles in driving the unconventional reactions or destructing the surface molecule layer. The acceleration or inhibition on this catalysis is still remained significant challenge. In this paper, monolayer film of Au nanoparticles was fabricated at air/water interface as substrates both for surface enhanced Raman spectroscopy (SERS) and plasmon catalyzed surface reaction. The influence from several issues, involving surfactants, coadsorption species, the solvent and water, were systemically investigated to probe the acceleration and inhibition on the plasmon catalysis reaction. The concentration and molecular weight of surfactant polyvinylpyrrolidone (PVP) exhibited significant influence in the reactive activity for the plasmon catalyzed dimerization of para-nitrothiophenol (PNTP) to p,p'-dimercaptoazobenzene (DMAB). A suitable molecular weight of 10,000 and concentration of 10mg/mL were beneficial for improving the conversion efficiency of PNTP to DMAB. The higher molar ratio of coadsorbed 1-octanethiol and the aprotic solvents resulted in the inhibition of dimerization because 1-octanethiol occupied the surface sites to isolate the adsorbed PNTP molecules with a larger distance and lack of proton source. The plasmon catalysis occurred in ionic liquids suggested that water was essential for the dimerization of PNTP, in which it was used to accelerate the reaction rate and severed as the hydrogen source.

Magnetic separation of heavy metal ions and evaluation based on surface-enhanced Raman spectroscopy: copper(II) ions as a case study.

A new approach was developed for the magnetic separation of copper(II) ions with easy operation and high efficiency. p-Mercaptobenzoic acid served as the modified tag of Fe2O3@Au nanoparticles both for the chelation ligand and Raman reporter. Through the chelation between the copper(II) ions and carboxyl groups on the gold shell, the Fe2O3@Au nanoparticles aggregated to form networks that were enriched and separated from the solution by a magnet. A significant decrease in the concentration of copper(II) ions in the supernatant solution was observed. An extremely sensitive method based on surface-enhanced Raman spectroscopy was employed to detect free copper(II) ions that remained after the magnetic separation, and thus to evaluate the separation efficiency. The results indicated the intensities of the surface-enhanced Raman spectroscopy bands from p-mercaptobenzoic acid were dependent on the concentration of copper(II) ions, and the concentration was decreased by several orders of magnitude after the magnetic separation. The present protocol effectively decreased the total amount of heavy metal ions in the solution. This approach opens a potential application in the magnetic separation and highly sensitive detection of heavy metal ions.

Supersaturation-dependent surface structure evolution: from ionic, molecular to metallic micro/nanocrystals.

Deduced from thermodynamics and the Thomson-Gibbs equation that the surface energy of crystal face is in proportion to the supersaturation of crystal growth units during the crystal growth, we propose that the exposed crystal faces can be simply tuned by controlling the supersaturation, and higher supersaturation will result in the formation of crystallites with higher surface-energy faces. We have successfully applied it for the growth of ionic (NaCl), molecular (TBPe), and metallic (Au, Pd) micro/nanocrystals with high-surface-energy faces. The above proposed strategy can be rationally designed to synthesize micro/nanocrystals with specific crystal faces and functionality toward specific applications.