A Population-Based Research Utilized a Risk Stratification Model to Forecast the Overall Survival of Young Women With Diagnosed Stage IV Breast Cancer.

BACKGROUND: The goal of this study is to develop a risk prediction model for estimating overall survival (OS) in young females diagnosed with stage IV breast cancer. METHODS: The clinical information was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. To identify the dependent risk factors, we utilized the Cox proportional hazards regression model in both single and multivariate analyses. We then created a new nomogram to predict the 1-, 3-, and 5-year overall survival probability for these patients based on the identified risk factors. RESULTS: Six hundred seventy-six patients who met the eligibility requirements were stochastically partitioned into training (n = 475) and validation (n = 201) groups in a 7:3 ratio. Histology, breast subtype, T classification, brain metastasis, bone metastasis, liver metastasis, and surgery were identified as independent prognostic factors for cancer. To predict the 1-, 3-, and 5-year overall survival (OS) probabilities, all of these independent factors were incorporated into nomograms. Our nomogram demonstrated a favorable discriminatory power, as evidenced by a C-index of 0.737 (95% CI: 0.708-0.766) and 0.717 (95% CI: 0.664-0.770) for the training and validation cohorts, respectively. The calibration curves showed satisfactory consistency in both cohorts. Using this nomogram, we developed a risk stratification model that categorized patients into low-, intermediate-, and high-risk groups. CONCLUSION: The prediction model was more precisely to predict the OS of young females with stage IV breast cancer and could enable individualized risk estimation that could be conducive to physicians exploring therapeutic strategies for effectiveness.

Improved antioxidant activity and delivery of peppermint oil Pickering emulsion stabilized by resveratrol-grafted zein covalent conjugate/quaternary ammonium chitosan nanoparticles.

Novel nanoparticles (Z-R/H) were successfully fabricated by a resveratrol-grafted zein covalent conjugate (Z-R) combined with quaternary ammonium chitosan (HTCC), which were used as stabilizers to prepare peppermint oil (PO) Pickering emulsions with antioxidant activity. HTCC effectively adjusted wettability of Z-R conjugate, and three-phase contact angle of Z-R/H3:1 was moderate (95.01°). The influencing factors of Pickering emulsion formation, including volume fraction of PO, concentration of Z-R/H, and mass ratio of Z-R to HTCC, were evaluated by droplet size, ζ-potential, microscopic observation, and stability index analysis. Pickering emulsions stabilized by Z-R/H3:1 showed excellent physical stability under heat treatment. Z-R/H nanoparticles adsorbed on the oil-water interface yielded a dense filling layer as a physical barrier to improve the emulsion stability, which was validated by confocal laser-scanning microscopy. After 4 weeks of storage, retention rate of PO in Pickering emulsion stabilized by Z-R/H3:1 remained high (72.1 %). Electronic nose analysis showed that Z-R/H3:1-stabilized emulsion effectively prevented volatilization of PO aroma components. Additionally, PO and Z-R/H nanoparticles provided an additive antioxidant effect of Pickering emulsions against DPPH and ABTS free radicals. In summary, these novel Z-R/H nanoparticle offer promising applications as a stabilizer with great potential in preparing functional Pickering emulsions to improve essential oil delivery.

The Role of Lignin in the Compartmentalization of Cadmium in Maize Roots Is Enhanced by Mycorrhiza.

In nature, arbuscular mycorrhizal fungi (AMF) play a crucial role in the root systems of plants. They can help enhance the resistance of host plants by improving the compartmentalization of toxic metal contaminants in the cell walls (CWs). However, the functions and responses of various CW subfractions to mycorrhizal colonization under Cd exposure remain unknown. Here we conducted a study to investigate how Cd is stored in the cell walls of maize roots colonized by Funneliformis mosseae. Our findings indicate that inoculating the roots with AMF significantly lowers the amount of Cd in the maize shoots (63.6 ± 6.54 mg kg-1 vs. 45.3 ± 2.19 mg kg-1, p < 0.05) by retaining more Cd in the mycorrhized roots (224.0 ± 17.13 mg kg-1 vs. 289.5 ± 8.75 mg kg-1, p < 0.01). This reduces the adverse effects of excessive Cd on the maize plant. Additional research on the subcellular distribution of Cd showed that AMF colonization significantly improves the compartmentalization of 88.2% of Cd in the cell walls of maize roots, compared to the 80.8% of Cd associated with cell walls in the non-mycorrhizal controls. We observed that the presence of AMF did not increase the amount of Cd in pectin, a primary binding site for cell walls; however, it significantly enhanced the content of lignin and the proportion of Cd in the total root cell walls. This finding is consistent with the increased activity of lignin-related enzymes, such as PAL, 4CL, and laccase, which were also positively impacted by mycorrhizal colonization. Fourier transform infrared spectroscopy (FTIR) results revealed that AMF increased the number and types of functional groups, including -OH/-NH and carboxylate, which chelate Cd in the lignin. Our research shows that AMF can improve the ability of maize plants to tolerate Cd by reducing the amount of Cd transferred from the roots to the shoots. This is achieved by increasing the amount of lignin in the cell walls, which binds with Cd and prevents it from moving through the plant. This is accomplished by activating enzymes related to lignin synthesis and increasing the exposure of Cd-binding functional groups of lignin. However, more direct evidence on the immobilization of Cd in the mycorrhiza-altered cell wall subfractions is needed.

Morphological and Compositional Analysis on Thermal Deposition of Supercritical Aviation Kerosene in Micro Channels.

The integration of active cooling systems in super or hypersonic aircraft using endothermic hydrocarbon fuels is considered an effective way to relieve the thermal management issues caused by overheating. When the temperature of aviation kerosene exceeds 150 °C, the oxidation reaction of fuel is accelerated, forming insoluble deposits that could cause safety hazards. This work investigates the deposition characteristic as well as the morphology of the deposits formed by thermal-stressed Chinese RP-3 aviation kerosene. A microchannel heat transfer simulation device is used to simulate the heat transfer process of aviation kerosene under various conditions. The temperature distribution of the reaction tube was monitored by an infrared thermal camera. The properties and morphology of the deposition were analyzed by scanning electron microscopy and Raman spectroscopy. The mass of the deposits was measured using the temperature-programmed oxidation method. It is observed that the deposition of RP-3 is highly related to dissolved oxygen content (DOC) and temperature. When the outlet temperature increased to 527 °C, the fuel underwent violent cracking reactions, and the structure and morphology of deposition were significantly different from those caused by oxidation. Specifically, this study reveals that the structure of the deposits caused by short-to-medium term oxidation are dense, which is different from long-term oxidative deposits.

Preparation of alginate-whey protein isolate and alginate-pectin-whey protein isolate composites for protection and delivery of Lactobacillus plantarum.

Probiotics are sensitive to external conditions, resulting in low survival rates after being ingested or during food production, transportation and storage. In order to improve the survival rate of Lactobacillus plantarum (LP) during gastrointestinal digestion, storage, and freeze-drying, alginate-whey protein isolate (ALG-WPI) and alginate-pectin-whey protein isolate (ALG-PEC-WPI) composites were employed to encapsulate LP. The encapsulation efficiency of ALG-WPI-LP and ALG-PEC-WPI-LP beads both reached more than 99 %. Scanning electron microscopy (SEM) indicated that dense and rough aggregates were formed on the surface of both composites, and attached LP cells could be observed inside the beads. The ALG-WPI and ALG-PEC-WPI composites can protect the viability of LP in simulated gastric fluid (SGF) and release the probiotics in simulated intestinal fluid (SIF). The storage stability of LP at 4 °C was improved by about 15 % in comparison with bare LP and the survival rates of LP in ALG-WPI-LP and ALG-PEC-WPI-LP powders after freeze-drying were increased by 65.37 % and 72.06 %, respectively. The formation mechanism of ALG-WPI and ALG-PEC-WPI composites was further explored by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The ALG-WPI and ALG-PEC-WPI composites have great potential to protect and deliver probiotics in food systems.

Experimental Studies on Parametric Effects and Reaction Mechanisms in Electrolytic Decomposition and Ignition of HAN Solutions.

The green propellant hydroxylammonium nitrate (HAN) is a good alternative to the conventional propellants in space propulsion applications because of its low toxicity and high energy density. Electrolytic decomposition and ignition of HAN solution, an ionic liquid, is a promising approach. In this work, comprehensive experimental studies were conducted to examine effects of different electrolytic voltages, electrode surface areas, and HAN concentrations on the decomposition process. In the test cases, an optimum electrolytic voltage appears to exist, which leads to the fastest decomposition process. As the voltage increases, a larger electrode surface area on the anode side should be used to overcome an anodic inhibition phenomenon and accelerate the electrolytic process. A high concentration of HAN solution is preferred for its decomposition and ignition. Results also reveal that the electrolytic process of a HAN solution could eventually trigger thermal decomposition reactions, raising the maximum temperature to around 550 K at the final stage. A detailed chemical reaction mechanism was proposed, based on the experimental data and FTIR spectra analyses. Results obtained herein would provide fundamental understandings on the complex electrochemical and physical processes and should be helpful for future applications of the electrolytic decomposition and ignition technology.

Preparation of zein-lecithin-EGCG complex nanoparticles stabilized peppermint oil emulsions: Physicochemical properties, stability and intelligent sensory analysis.

Peppermint oil emulsions were prepared by using zein-lecithin-EGCG (Z-L/E) complex nanoparticles as emulsifiers. The preparation conditions of emulsions were optimized via measuring the particle size, surface tension and stability of emulsions, and peppermint oil of 3% (particle size = 375 nm, polydispersity index (PDI) = 0.45), the zein:lecithin ratio of 4:1 (w/w) (particle size = 396 nm), and the zein:EGCG ratio of 10:1 (w/w) (surface tension = 47.32 N/m) was the optimal condition. The rapid stability analysis showed that the instability mechanism of emulsions was ascribed to creaming and stratification, and the stability mechanism of emulsions was explored, indicating that the complex nanoparticles adsorbed on the surface of oil droplets to give Pickering emulsions. Electronic tongue experiments showed that the Z-E/L4:1 stabilized emulsion was distinguished from the other three samples due to its good stability. The electronic nose experiment could distinguish the emulsions with different droplet sizes.

Nanoengineered on-demand drug delivery system improves efficacy of pharmacotherapy for epilepsy.

Long-term pharmacotherapy, serving as the main therapeutic approach for epilepsy prophylaxis, has suffered from limited efficacy and potential side effects because of the blood-brain barrier (BBB) and untimely medication. Here, we reported a nanoengineered drug delivery system for synergistic brain-targeting delivery and on-demand drug release of antiepileptic drugs (AEDs). The dopamine-pyrrole hybrid system can improve delivery efficiency through a combination of receptor-mediated transcytosis and BBB disruption­enabled transport induced by photothermal conversion of near-infrared light. Incorporation of polydopamine endowed the delivery system with enhanced conductivity and sensitivity, giving sustained (2 hours) and rapid (30 s) drug release in response to epileptiform discharges. Acute, continuous, and spontaneous seizure models validated that the delivery system could inhibit seizures upon epileptiform abnormalities, treated by one-fifth of the conventional dosage. Complemented with satisfactory biosafety results, this "smart" modality is promising to be an effective and safe strategy to improve the therapeutic index of AEDs for epilepsy.

Exploration of the Microstructure and Rheological Properties of Sodium Alginate-Pectin-Whey Protein Isolate Stabilized Β-Carotene Emulsions: To Improve Stability and Achieve Gastrointestinal Sustained Release.

Sodium alginate (SA)-pectin (PEC)-whey protein isolate (WPI) complexes were used as an emulsifier to prepare ß-carotene emulsions, and the encapsulation efficiency for ß-carotene was up to 93.08%. The confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) images showed that the SA-PEC-WPI emulsion had a compact network structure. The SA-PEC-WPI emulsion exhibited shear-thinning behavior and was in a semi-dilute or weak network state. The SA-PEC-WPI stabilized ß-carotene emulsion had better thermal, physical and chemical stability. A small amount of ß-carotene (19.46 ± 1.33%) was released from SA-PEC-WPI stabilized ß-carotene emulsion in simulated gastric digestion, while a large amount of ß-carotene (90.33 ± 1.58%) was released in simulated intestinal digestion. Fourier transform infrared (FTIR) experiments indicated that the formation of SA-PEC-WPI stabilized ß-carotene emulsion was attributed to the electrostatic and hydrogen bonding interactions between WPI and SA or PEC, and the hydrophobic interactions between ß-carotene and WPI. These results can facilitate the design of polysaccharide-protein stabilized emulsions with high encapsulation efficiency and stability for nutraceutical delivery in food and supplement products.

Fabrication and characterization of oil-in-water pickering emulsions stabilized by ZEIN-HTCC nanoparticles as a composite layer.

In this work, the ZEIN-HTCC nanoparticles formed by zein and N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC) were used as stabilizers to prepare oil-in-water (O/W) Pickering emulsions. The preparation conditions including shearing time, volume fraction of corn oil, mass ratio of ZEIN:HTCC and total concentration of ZEIN-HTCC of emulsions were optimized by measuring the droplet size, zeta potential, PDI and surface tension of emulsions. The ZEIN-HTCC emulsions are stable at the pH range of 4-9 and in the low salt ion concentrations up to 0.2 mol L-1, and can keep stable up to 21 d during low temperature storage. Fourier transform infrared spectroscopy (FTIR), the confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM) were used to analyze the interaction between emulsion components, revealing that zein and HTCC form a composite layer by flocculation to adsorb on the surface of oil droplets, thus preventing emulsion droplets from aggregation. This novel, long-term stable, surfactant-free, and edible zein-based Pickering emulsion could be used as potential carriers for lipophilic nutrients delivery.

The regulation of sodium alginate on the stability of ovalbumin-pectin complexes for VD3 encapsulation and in vitro simulated gastrointestinal digestion study.

The ovalbumin (OVA)-pectin (PEC)-sodium alginate (SA)-Vitamin D3 (VD3) complex nanoparticles were fabricated by antisolvent precipitation method, and the excellent encapsulation efficiency and loading capacity of VD3 were obtained by 96.6% and 2.8%, respectively. Compared with ternary OVA-PEC-VD3 complexes, the addition of SA with strong negative charge effectively regulated the OVA-PEC complexes and significantly improved the stability of OVA-PEC-SA-VD3 complex nanoparticles with preferable size as small as 126 nm. The storage stability was also investigated after low temperature storage for 31 d, and the particle size of quaternary complexes was increased only 40 nm. In vitro digestion results elucidated that the complex nanoparticles had good stability in the simulated gastric fluid, and almost completely released in the simulated intestinal fluid confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) experiments and scanning electron microscope (SEM) images. The release kinetics study clarified that it was close to Fick release. Fluorescence and Fourier transform infrared spectroscopy (FTIR) experiments showed that quaternary complex nanoparticles were mainly combined by electrostatic, hydrophobic and hydrogen bonding interactions. The novel quaternary protein-polysaccharide complexes have excellent stability and great sustained-release performance for VD3, which may be helpful for the digestion and absorption of vitamin by human body, thus have potential applications in the food and drug industry.

PdAgPt Corner-Satellite Nanocrystals in Well-Controlled Morphologies and the Structure-Related Electrocatalytic Properties.

The functions of heterogeneous metallic nanocrystals (HMNCs) can be undoubtedly tuned by controlling their morphologies and compositions. As a less-studied kind of HMNCs, corner-satellite multi-metallic nanocrystals (CSMNCs) have great research value in structure-related electrocatalytic performance. In this work, PdAgPt corner-satellite nanocrystals with well-controlled morphologies and compositions have been developed by temperature regulation of a seed-mediated growth process. Through the seed-mediated growth, the morphology of PdAgPt products evolves from Pd@Ag cubes to PdAgPt corner-satellite cubes, and eventually to truncated hollow octahedra, as a result of the expansion of {111} facets in AgPt satellites. The growth of AgPt satellites exclusively on the corners of central cubes is realized with the joint help of Ag shell and moderate bromide, and hollow structures form only at higher reaction temperatures on account of galvanic displacement promoted by the Pd core. In view of the different performances of Pd and Pt toward formic acid oxidation (FAO), this structure-sensitive reaction is chosen to measure electrocatalytic properties of PdAgPt HMNCs. It is proven that PdAgPt CSMNCs display greatly improved activity toward FAO in direct oxidation pathway. In addition, with the help of AgPt heterogeneous shells, all PdAgPt HMNCs exhibit better durability than Pd cubes and commercial Pt.

Improved Stability and Targeted Cytotoxicity of Epigallocatechin-3-Gallate Palmitate for Anticancer Therapy.

Although with high antioxidant activity, epigallocatechin-3-gallate (EGCG) was restricted by its poor chemical stability in practical applications. One of EGCG derivatives, EGCG palmitate, was synthesized with EGCG and palmitoyl chloride to overcome instability of EGCG. However, uncertainties still exist in chemical stability and cytotoxicity of EGCG palmitate, which are essential for further exploration in anticancer therapy. Our work aims to analyze the resistance of EGCG palmitate to oxidation and summarize its targeted inhibition efficiency on cancerous cells and normal cells. High-performance liquid chromatography analysis confirmed that EGCG palmitate remained stable in air and Dulbecco's modified eagle medium (DMEM) for a longer time than EGCG. Antioxidative and pro-oxidative effects of EGCG palmitate on treated cells are proposed through reactive oxygen species (ROS) detection, respectively. It reveals that pro-oxidants by H2O2 production can exert antiproliferative and proapoptotic effects on cancerous cells and stimulate autophagy, while an antioxidant relieves oxidative stress caused by superoxide as compared to normal cells. Consequently, targeted cytotoxicity is adopted by EGCG palmitate-treated cancerous cells. Results above manifest that EGCG palmitate possesses potential to serve as a promising prodrug in anticancer treatment.

Thermal Conductivity and Stability of Hydrocarbon-Based Nanofluids with Palladium Nanoparticles Dispersed by Modified Hyperbranched Polyglycerol.

Palladium nanoparticles, which were prepared by modified hyperbranched polyglycerol (mHPG) as stabilizers, can be dispersed well in nonpolar organic solvents and form highly stable nanofluids. The influences of three mHPG products modified with cyclohexanethiol (CSHPG), dodecanethiol (DSHPG), and octadecanethiol (OSHPG) on the preparation and stability of the palladium nanoparticles were investigated. The stability and thermal conductivity enhancement of the hydrocarbon-based nanofluids with Pd@mHPG (Pd@CSHPG, Pd@DSHPG, and Pd@OSHPG) compared to the corresponding base fluid were investigated at different temperatures. The average diameters of nanoparticles stabilized by CSHPG, DSHPG, and OSHPG are within 2.7-3.6 nm. The palladium nanoparticles could be dispersed well in the nonpolar base fluid such as decalin. The nanofluids with Pd@DSHPG and Pd@OSHPG could remain stable for up to 330 days at room temperature. The nanofluid with Pd@DSHPG or Pd@OSHPG could be stable for more than 24 h at 110 °C. The thermal conductivity of the nanofluids improved with increasing temperature and the mass fraction of nanoparticles compared to the corresponding base fluid. The long alkyl chain-modified HPG can give better protection for nanoparticles from agglomeration and assist metal nanoparticles in enhancing the thermal conductivity of nanofluids.

Mesoporous polydopamine with built-in plasmonic core: Traceable and NIR triggered delivery of functional proteins.

Functional proteins are essential for the regulation of cellular behaviors and have found growing therapeutic uses. However, low bioavailability of active proteins to their intracellular targets has been a long-standing challenge to achieve their full potential for cell reprogramming and disease treatment. Here we report mesoporous polydopamine (mPDA) with a built-in plasmonic nanoparticle core as a multifunctional protein delivery system. The mPDA with a unique combination of large surface area, metal-chelating property, and broad-spectrum photothermal transduction allows efficient loading and near-infrared light-triggered release of functional proteins, while the plasmonic core serves as a photostable tracer and fluorescence quencher, collectively leading to real-time monitoring and active cytosolic release of model proteins. In particular, controlled delivery of cytotoxic ribonuclease A has shown excellent performance in invivo cancer therapy. The possibility of coating mPDA on a broad range of functional cores, thanks to its universal adhesion, provides opportunities for developing tailored delivery carriers of biologics to overcome intrinsic biological barriers.

Duo of (-)-epigallocatechin-3-gallate and doxorubicin loaded by polydopamine coating ZIF-8 in the regulation of autophagy for chemo-photothermal synergistic therapy.

To achieve highly systemic therapeutic efficacy, chemotherapy is combined with photothermal therapy for chemo-photothermal synergistic therapy; however, this strategy suffers from high toxicity and unsatisfactory sensitivity for cancer cells. Herein, we developed a pH- and photothermal-responsive zeolitic imidazolate framework (ZIF-8) compound for loading a dual-drug in the tumor site and improving their curative effects. Since autophagy always accompanies tumor progression and metastasis, there is an unmet need for an anticancer treatment related to the regulation of autophagy. Green tea polyphenols, namely, (-)-epigallocatechin-3-gallate (EGCG) and doxorubicin (DOX), both of which exhibit anticancer activity, were dual-loaded via polydopamine (PDA) coating ZIF-8 (EGCG@ZIF-PDA-PEG-DOX, EZPPD for short) through hierarchical self-assembly. PDA could transfer photothermal energy to increase the temperature under near-infrared (NIR) laser irradiation. Due to its pH-response, EZPPD released EGCG and DOX in the tumor microenvironment, wherein the temperature increased with the help of PDA and NIR laser irradiation. The duo of DOX and EGCG induced autophagic flux and accelerated the formation of autophagosomes. In a mouse HeLa tumor model, photothermal-chemotherapy could ablate the tumor with a significant synergistic effect and potentiate the anticancer efficacy. Thus, the results indicate that EZPPD renders the key traits of a clinically promising candidate to address the challenges associated with synergistic chemotherapy and photothermal utilization in antitumor therapy.

New Strategy for High-Performance Integrated Catalysts for Cracking Hydrocarbon Fuels.

In this study, we described the synthesis, characterization, and application of hyperbranched polymer-encapsulated metal nanoparticles (HEMNs) as integrated catalysts for the supercritical cracking of hydrocarbon fuels. The metal precursor was extracted into the organic phase using a hydrocarbon-soluble hyperbranched poly(amidoamine) (CPAMAM) and then reduced in situ by NaBH4 to produce HEMNs with virtually a single-size distribution. The monitoring of the preparation process by UV-vis demonstrated the feasibility of this encapsulation approach, and the successful synthesis of three different types of HEMNs, metal (Pd, Pt, Au)@CPAMAM, reflected the universality of this method. Compared with the existing catalyst octadecylamine-stabilized Pd nanoparticle, Pd@18N, HEMNs were superior in every aspect. The new encapsulation method allowed metal NPs to have a smaller particle size beneficial to their overall specific surface area and a higher proportion of active surface atoms for a better catalytic activity. Moreover, the space-limiting effect of the polymer allowed the three HEMNs to be highly dispersed in decalin and exhibited admirable stability under storage tests for up to 12 months and high-temperature stability tests at 180 °C. During the supercritical cracking of decalin, Pd@CPAMAM possessed a much better catalytic performance than Pd@18N and CPAMAM (which can also be used as a macroinitiator). To obtain the same heat sink of 3.02 MJ/kg, the temperature could be lowered from 725 to 701, 693, and 699 °C for Pd, Pt, and Au HEMNs, respectively. Pt HEMN turned out to be the best due to its excellent catalytic dehydrogenation/cracking performance, with the conversion of decalin increasing from 22.3 to 50.7% and the heat sink rising from 2.18 to 2.62 MJ/kg with the existence of 50 ppm Pt@CPAMAM, at 675 °C. The significant enhancements were ascribed to the synergistic catalysis through the remarkable abilities of nanometals to catalyze dehydrogenation/cracking of fuel, the supercritical stabilization effects from CPAMAM, and the initiation effects of the hyperbranched polymer CPAMAM.

A combined experimental and theoretical study on the structures, interactions and volumetric properties of guanidinium-based ionic liquid mixtures.

Mixtures of ionic liquids (ILs) have shown their potential in both physical and chemical processes, regarded as alternatives to common ILs. In this work, four guanidinium-based ILs, 2-ethyl-1,1,3,3-tetramethylguanidinium ethyl sulfate ([TMG(C2)][C2OSO3]) and bis(trifluoromethylsulfonyl)imide ([TMG(C2)][NTf2]), and 2,2-diethyl-1,1,3,3-tetramethylguanidinium ethyl sulfate ([TMG(C2)2][C2OSO3]) and bis(trifluoromethylsulfonyl)imide ([TMG(C2)2][NTf2]), are employed to investigate the structures, interactions and properties of four systems of IL-IL binary mixtures, including [TMG(C2)][C2OSO3]x[NTf2]1-x, [TMG(C2)]x[TMG(C2)2]1-x[C2OSO3], [TMG(C2)]x[TMG(C2)2]1-x[NTf2] and [TMG(C2)2][NTf2]x[C2OSO3]1-x. Combining experiments with theory, the relationships among H-bond interactions, structures and volumetric properties have been revealed. 1H NMR characterizations show the changes of H-bond interactions in the IL-IL mixtures in relation to composition, and DFT calculations reveal significant cation-anion interactions through the active hydrogen atom (N+-H) and the methyl groups in the cations with the anions in the manner of HO and HF. The ethyl group in the [C2OSO3]- anion hardly forms interactions with other components. The size effect of the calculated system has been evaluated for the IL-IL clusters with 2, 4 and 8 ions. Different structures due to variation of cationic and anionic species have remarkable influence on the volumetric properties of the IL-IL mixtures. Negative excess molar volume (VEm) is found in [TMG(C2)]x[TMG(C2)2]1-x[C2OSO3], and it is caused by the close packing of ions. Positive VEm values indicate that interaction loss occurs in the other three systems, where a linear arrangement or square packing of ions with low space utilization is found.

Intracellular and Cellular Detection by SERS-Active Plasmonic Nanostructures.

Surface-enhanced Raman scattering (SERS), with greatly amplified fingerprint spectra, holds great promise in biochemical and biomedical research. In particular, the possibility of exciting a library of SERS probes and differentially detecting them simultaneously has stimulated widespread interest in multiplexed biodetection. Herein, recent progress in developing SERS-active plasmonic nanostructures for cellular and intracellular detection is summarized. The development of nanosensors with tailored plasmonic and multifunctional properties for profiling molecular and pathological processes is highlighted. Future challenges towards the routine use of SERS technology in quantitative bioanalysis and clinical diagnostics are further discussed.

DFT studies on mechanistic origins of ligand-controlled selectivity in Pd-catalyzed non-decarbonylative and decarbonylative reductive conversion of acyl fluoride.

The mechanisms and origins for ligand-controlled non-decarbonylative and decarbonylative conversions of acyl fluorides catalyzed by palladium catalysts with different ligands tricyclohexylphosphine (PCy3) and 1,2-bis(dicyclohexylphosphino)ethane (DCPE) have been investigated by density functional theory (DFT) calculations. In the case of the DCPE ligand, the favorable catalytic cycle contains four steps, oxidative addition, decarbonylation, transmetallation and reductive elimination. In the case of the PCy3 ligand, the favorable catalytic cycle proceeds by three steps, oxidative addition, transmetallation and reductive elimination. Distortion/interaction analysis indicated that decarbonylation does not occur for PCy3 owing to the repulsive interaction between PCy3 and substrates. Present calculations agree with the experimental observations and understanding these surprising ligand-controlled non-decarbonylative and decarbonylative selectivity reactions could provide important insights into the development of selective catalyst systems.