Carbon Defects as Highly Active Sites for Gold Detection and Recovery.

The use of precious metals (PMs) in many areas, such as printed circuit boards, catalysts, and target drugs, is increasing due to their unique physical and chemical properties, but their recovery remains a great challenge in terms of zero-valent PMs as final product. We report a highly hydrophilic carbon dot (CD) as reductant (electron donor), the defects in CD served as efficient active sites for zero-valent PMs recovery with an electron-donating capacity is ~1.7 mmol g-1.

Online Privacy-Preserving EEG Classification by Source-Free Transfer Learning.

Electroencephalogram (EEG) signals play an important role in brain-computer interface (BCI) applications. Recent studies have utilized transfer learning to assist the learning task in the new subject, i.e.

Stability assessment of surrounding rock in downward mining route supported by slab-wall backfill structure.

Characteristic of ground pressure in surrounding rock is generally considered as the theoretical basis of parameter optimization for stope structure and technology. To explore the feasibility of efficient method for the second-step downward route backfill stopes in Shanjin gold mine, various numerical simulation methods were used to investigate the effect of slab-wall backfill structure on stability of surrounding rock in downward route mining system. The maximum principal stress, artificial false roof stress, and displacement were analyzed to evaluate the level of ground pressure in different mining areas.

[Progress of highly reproducible capillary electrophoresis].

Following rapid developments in capillary electrophoresis (CE), this technology has become an established analytical technique owing to its microscale characteristics, high speed, high efficiency, and versatility. However, the challenges of poor peak stability and/or reproducibility have consistently hindered its wider applications. CE has long been used as a measurement tool for plotting signal intensities versus the migration time; however, the migration time is not an independent variable in CE, but is affected by many direct and indirect parameters, including capillary (length, diameter, and inner surface properties), electric field (or voltage, current, and/or power), temperature, and running buffer (electrolytes, additives, solvents, and their concentration, buffering pH, etc.

Solar-assisted selective separation and recovery of precious group metals from deactivated air purification catalysts.

The mitigation of environmental and energy crises could be advanced by reclaiming platinum group precious metals (PGMs) from decommissioned air purification catalysts. However, the complexity of catalyst composition and the high chemical inertness of PGMs significantly impede this process. Consequently, recovering PGMs from used industrial catalysts is crucial and challenging.

Label-free analysis of membrane protein binding kinetics and cell adhesions using evanescent scattering microscopy.

Measuring ligand interactions with membrane proteins in single live cells is critical for understanding many cellular processes and screening drugs. However, developing such a capability has been a difficult challenge. Here, we employ evanescent scattering microscopy (ESM) to show that ligand binding to membrane proteins can change the cell adhesion properties, which are intrinsic cell properties and independent of random cell micromotions and ligand mass, thus allowing the kinetics analyses of both proteins and small molecules binding to membrane proteins in both single fixed and live cells.

Transferable multi-modal fusion in knee angles and gait phases for their continuous prediction.

The gait phase and joint angle are two essential and complementary components of kinematics during normal walking, whose accurate prediction is critical for lower-limb rehabilitation, such as controlling the exoskeleton robots. Multi-modal signals have been used to promote the prediction performance of the gait phase or joint angle separately, but it is still few reports to examine how these signals can be used to predict both simultaneously.To address this problem, we propose a new method named transferable multi-modal fusion (TMMF) to perform a continuous prediction of knee angles and corresponding gait phases by fusing multi-modal signals.

Capillary array electrophoresis imaging of biochemicals in tissue sections.

It is of great significance to reveal the molecular distribution images in biological tissues, which has led to the bloom of mass spectrometry imaging. Unfortunately, its application is encountering the resistance of high technical barriers and equipment cost, as well as the inability to image substances that cannot be desorbed or ionized, or cannot be separated by their mass-to-charge ratios. Herein presented is a complementary and cost-effective method called capillary array electrophoresis (CAE) imaging.

Design, synthesis and bioevaluation of 2,7-diaryl-pyrazolo[1,5-a]pyrimidines as tubulin polymerization inhibitors.

Two series of 2,7-diaryl-pyrazolo[1,5-a]pyrimidines as tubulin polymerization inhibitors were designed to restrict bioactive configuration of (E,Z)-vinylogous CA-4. All of the target compounds were synthesized and then evaluated for their in vitro antiproliferative activities against three cancer cell lines (MCF-7, SGC-7901 and A549). Among them, 6d exhibited the most potent antiproliferative activity against the MCF-7 with IC value of 0.

A substantial increase of analytical throughput in capillary electrophoresis throughput by separation-interrupted sequential injections.

How to further improve the throughput of capillary electrophoresis (CE) is a fascinating question. Herein an idea to substantially increase the throughput of CE has been proposed together with theory and experimental demonstration. The key is to introduce samples for CE, one after another, by a short suspension of voltage application, which was hence termed separation-interrupted sequential injections (Sisi).

A stable version of capillary electrophoresis for determining human hemoglobin chains aiming at the screening and diagnosis of thalassemia.

As a fast, high-performance and cost-effective separation technique, capillary electrophoresis (CE) is applicable to the screening and diagnosis of diseases such as thalassemia. However, it is often not preferred due to its unrepeatable and/or irreproducible migration times. Herein, we propose a stable version of CE that uses migration charge density instead of the migration time to plot the electropherogram.

Background subtraction via time continuity and texture consistency constraints.

Background subtraction has attracted enormous interest in the field of moving object detection. However, when there are complex scenarios such as illumination changes, dynamic background, and noise, the moving object area obtained by background subtraction often has holes, noise, and shadows. This paper proposes a novel background update model based on matrix factorization, which uses the temporal continuity of video content to solve the problems of holes, noise, and shadows.

One-pot sample preparation approach for profiling spatial distribution of gibberellins in a single shoot of germinating cereal seeds.

Sample preparation remains a bottleneck in the rapid and reliable quantification of gibberellins (GAs) for obtaining an insight into the physiological processes mediated by GAs. The challenges arise from not only the extremely low content of GAs in complex plant matrices, but the poor detectability of GAs by mass spectrometry (MS) in negative ion mode. In an effort to solve these urgent difficulties, we present a spatial-resolved analysis method to investigate the distribution of GAs in tiny plant tissues based on a simplified one-pot sample preparation approach coupled with ultrahigh-performance liquid chromatography-tandem MS.

A bi-end injection capillary electrophoresis method for simultaneous determination of 37 cations and anions in beers.

Capillary electrophoresis (CE) is excellent at separating all the ions in a sample but is rarely used as a result of its detection issue and easy loss of very fast ions by common one-end injection methods. Herein we propose a newly developed method aimed at simultaneous determination of positive and negative ions with a home-made CE device, featuring bi-end injection and contactless conductivity detection at the middle. By simply using 2.

Facile derivatization of ultratrace carboxylic acids in saliva for quantification by HPLC-MS/MS.

It remains an issue to directly quantify trace biologically important carboxyl compounds in body fluids. Herein we propose an innovative method to determine α-lipoic acid, 2-(β-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman, prostaglandin E, cholic acid, and chenodeoxycholic acid in saliva. The method consists of two successive steps: fast and direct labeling of the target analytes with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide followed by ultrahigh-performance liquid chromatography-tandem mass spectrometry analysis.

Quantification of near-attomole gibberellins in floral organs dissected from a single Arabidopsis thaliana flower.

There remains a methodological bottleneck in the quantification of ultra-trace plant hormones in very tiny plant organs at fresh weights below a milligram. The challenge becomes even more serious in the determination of endogenous gibberellins (GAs), which are a class of compounds that are difficult to separate and detect. Herein, a quantification method using ultra-high-performance liquid chromatography-tandem mass spectrometry was developed, combined with a derivatization technique in which GAs react with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide in ethanol.

[Recent advancement of photonic-crystal-based analytical chemistry].

Photonic crystals are a type of novel materials with ordered structure, nanopores/channels and optical band gap. They have hence important applications in physics, chemistry, biological science and engineering fields. This review summarizes the recent advancement of photonic crystals in analytical chemistry applications, with focus on sensing and separating fields happening in the nearest 5 years.

Generic lures attract cerambycid beetles in a tropical montane rain forest in southern China.

The attraction of cerambycid beetles to 10 known cerambycid pheromones was tested in a tropical montane rain forest in southern China. From 28 May to 25 June 2010, 1,526 cerambycids representing 71 species were captured in pheromone-baited traps, with 14 species accounting for 92% of the specimens. Test compounds with a 3-hydroxyalkan-2-one or 2,3-alkanediol motif attracted significant numbers of both sexes for eight species in the subfamily Cerambycinae, including species of Demonax, Rhaphuma, and Xylotrechus.

Red emissive cross-linked chitosan and their nanoparticles for imaging the nucleoli of living cells.

Biocompatible glutaraldehyde-cross-linked chitosan with new red fluorescence were prepared for the first time and were shaped into nanoparticles via inverse-microemulsion method. They could luminesce at ca. 670 nm either as powders and nanoparticles or in real and gelling solutions or suspensions, having a lifetime of 1.

Ultrafast coating procedure for graphene on solid-phase microextraction fibers.

Graphene's unsurpassed specific surface area (up to 2630 m(2)/g) makes it be an ideal absorbent. To promote its use as a sorption coating in solid phase microextraction, an ultrafast method was established, able to coat a stable layer of graphene on a metal fiber in only 23s, with adjustable coating thickness between 10 and 40 µm by using sleeve barrels. The core idea includes: (1) use of semi-polymerized dimethylsiloxane as a sticky pre-liner to glue graphene and (2) rapid conversion from pre-liner to elastic polydimethylsiloxane (PDMS) to fix the glued graphene.

Separation and determination of chiral composition in penicillamine tablets by capillary electrophoresis in a broad pH range.

A chiral capillary electrophoretic method with nearly full pH window was explored for the separation and determination of dl-penicillamine. A facile one-pot labeling technique was coupled in the method for introduction of chromophore and charge groups onto the analytes to facilitate the electromigration and sensitive detection. By using simply a cost-effective neutral β-cyclodextrin as chiral selector, baseline separation of the dl-penicillamine was achieved from pH 2.

One-pot labeling-based capillary zone electrophoresis for separation of amino acid mixture and assay of biofluids.

A fast, simple and cost-effective one-pot labeling strategy coupled with capillary zone electrophoresis was developed for the complete separation of amino acid mixture. The strategy includes two steps of reactions: Cyanuric chloride was made to react first with 7-amino-1,3-naphthalenedisulfonic acid monopotassium salt at 0 °C for 10 min, and then with amino acids at 55 °C for 6 min. The resulted products, after diluted with water, were injected into capillary zone electrophoresis system for separation.

Electromigration diffusivity spectrometry: a way for simultaneous determination of diffusion coefficients from mixed samples.

A novel method was proposed for simultaneous measurement of diffusion coefficients, (D), from mixed samples by electrophoresis and termed electromigration-based diffusivity spectrometry. After theoretical treatment, D-equation for practical use has been deduced. With a modified CE system built in laboratory, electromigration-based diffusivity spectrometry has been realized and validated to suit for fast and accurate determination of diffusivities of mixed aromatic amino acids, phenols and aromatic organic acid, giving diffusivity spectra by peak area versus D, much similar to mass spectra.

Separation of dansylated amino acid enantiomers by chiral ligand-exchange CE with a zinc(II) L-arginine complex as the selecting system.

A facile chiral ligand-exchange capillary electrophoretic method has been explored for the enantioseparation and UV detection of dansyl-amino acids with Zn(II) L-arginine complex as a chiral selecting system. Successful enantioseparation of 17 pairs of amino acid enantiomers has been achieved with a buffer of 100 mM boric acid, 5 mM ammonium acetate, 3 mM ZnSO4 and 6 mM L-Arg at pH 8.0, of which 10 pairs were fully resolved with resolution in between 1.