Latest ArticlesThe effective extracting Cr(VI) from chromite ore processing residue (COPR) is the key to achieve COPR detoxification and recovery. We developed an effective method to extract Cr(VI) from COPR via controlling the phase transformation of Cr(VI)-containing minerals. Characteristic analysis showed that Cr(VI) was mainly incorporated in the hydrocalumite (NaCa4Al2O6(SO4/CrO4)1.5·15H2O) in COPR, which was a layered-double hydroxide (LDH) with multilayer structure. In the hydrothermal treatment experiments, the Na2CO3 solution showed significant extraction effect of Cr(VI) and detoxification effect of COPR. After treatment, 95% of Cr(VI) was removed and the Cr(VI) concentration in the leachate was decreased to 1.6 mg/L by the toxicity characteristic leaching procedure (TCLP), within the regulatory limit disposal standard (HJ/T 301-2007, 3 mg/L). Further study revealed that, during the treatment, hydrocalumite transformed into calcite (CaCO3) under the effect of mineralizer, therefore, the layered structure collapsed and the incorporated Cr(VI) was released to the supernatant. Meanwhile, the Cr(VI) desorbed from calcite with the calcite particles grew into large size with smooth surface. Stir-flow experiment revealed that the amount of chromium released from CORP to the environment was significantly reduced after treatment, and it is safer for landfill disposal. This work will provide an instructive guidance for the detoxification and recovery of COPR.
By virtue of electrochemistry, a series of α, α-dihaloacetophenones were easily obtained with good to excellent yields. This electrochemical procedure was taken in a divided cell with constant current in aqueous media. The reaction can be carried out smoothly at room temperature under metal and oxidant free condition, which provides an eco-friendly synthesis for the α, α-dihaloacetophenone derivatives.
Chlorinated organic pollutants (COPs) have caused serious contaminants in soil and groundwater, hence developing methods to remove these pollutants is necessary and urgent. By a simple hydrothermal method, we synthesized the bimetallic iron-nickel sulfide (FeNiS) particles which exhibited excellent catalytic property of COPs removal. FeNiS was chosen as the peroxydisulfate (PDS) activator to removal COPs including 4-chlorophenol (4-CP), 1, 4-dichlorophenol (1, 4-DCP) and 2, 4, 6-trichlorophenol (2, 4, 6-TCP). The results show that FeNiS can efficiently activate PDS to produce sulfate radical (SO4·-) which plays major role in the oxidative dechlorination and degradation due to its strong oxidizing property and the ability of producing hydroxyl radicals (·OH) in the alkaline condition. Meanwhile, the Cl- abscised from COPs during the dechlorination can turn into the chlorine radicals and enhance the degradation and cause further mineralization of intermediate products. This bimetallic FeNiS catalyst is a promising PDS activator for removal of chlorinated organics.
Bladder cancer is the most common malignant tumor in the urinary system, with high morbidity, mortality and recurrence after surgery. However, current bladder cancer urine diagnosis methods are limited by the low accuracy and specificity due to the low abundance of bladder cancer biomarkers in the urine with complex biological environments. Herein, we present a high stability indium gallium zinc oxide field effect transistor (IGZO-FET) biosensor for efficient identification of bladder cancer biomarkers from human urine samples. The recognition molecular functionalized IGZO-FET biosensor exhibits stable electronic and sensing performance due to the large-area fabrication of IGZO thin-film FET. Owing to the excellent electrical performance of IGZO-FET, the IGZO-FET biosensor exhibits high sensitivity and extremely low detection limit (2.7 amol/L) towards bladder cancer biomarkers. The IGZO-FET biosensor is also able to directly detect bladder tumor biomarker in human urine with high sensitivity and specificity, and could differentiate bladder cancer patients' urine samples from healthy donors effectively. These results indicate that our designed high-performance biosensor shows great potential in the application of portable digital bladder cancer diagnosis devices.
The synthesized near infrared molybdenum oxide quantum dots perform excellent red fluorescence imaging performance and photothermal performance, which have 600, 650 and 700 nm three unique peaks excited at 540 nm, with a high quantum yield around 20%. Meanwhile, with 808 nm NIR laser excitation, 10 mg/mL modified Molybdenum oxide quantum dots can increase temperature up to 72.2 ℃ within 150 s and 77.7 ℃ within 270 s, respectively.
Metalloenzymes which employ metal species and organic ligands as central active sites play significant roles in various biological activities. Development of artificial metalloenzymes can help to understand the related physiological mechanism and promote the applications of metalloenzymes in biosynthesis, energy conversion and biosensing. In this work, inspired by the active sites of ferriporphyrin-based metalloenzymes, Fe-MOFs by using ferric as the metal center and a porphyrin analog as the organic ligand were developed as an artificial metalloenzyme. The Fe-MOFs exhibit high peroxidase-like catalytic activity with excellent long-term stability. Moreover, highly sensitive biosensors were built to detect H2O2 and glucose based on the Fe-MOFs. Such MOFs-based artificial metalloenzyme offers an efficient strategy for the development of highly stable and efficient metalloenzymes, showing great potential in catalysis, energy transfer, biosensing and medical diagnosis.
Rapid detection and identification of Escherichia coli (E. coli) is essential to prevent its quickly spread. In this study, a novel fluorescence probe based on ZnTe quantum dots (QDs) modified by mannose (MAN) had been prepared for the determination of E. coli. The results showed that the obtained QDs showed excellent selectivity toward E. coli, and presented a good linearity in range of 1.0×105~1.0×108 CFU/mL. The optimum fluorescence intensity for detecting E. coli was found to be at pH 7.0 with a temperature of 25 ℃ and incubation time of 20 min. Under these optimum conditions, the detection limit of E. coli was 4.6×104 CFU/mL. The quenching was discussed to be a static quenching procedure, which was proved by the quenching efficiency of QDs decreased with the temperature increasing.
Effective detection of cellular microenvironments and understanding of physiological activities in living cells remain a considerable challenge. In recent years, fluorescence (or Förster) resonance energy transfer (FRET) technology has emerged as a valuable method for real-time imaging of intracellular environment with high sensitivity, specificity and spatial resolution. Particularly, polymer-based imaging systems show enhanced stability, improved biodistribution, increased dye payloads, and amplified signal/noise ratio compared with small molecular sensors. This review summarizes the recent progress in FRET-based polymeric systems for probing the physiological environments in cells.
As a daily food for billions of people for thousands of years, whole grain is rich in phenolic compounds and may have huge potentials to provide natural antioxidants. Herein, owing to the significant biomedical potential, the effect of whole wheat flour solution as antioxidant wound coating for enhanced wound healing has been studied. The results show that the low concentration of whole wheat flour solutions have good biocompatibility and can scavenge radical and intracellular ROS in vitro, accelerating tissue remodeling in vivo to promote wound healing. This kind of whole wheat flour solution has great potential application for cutaneous wound repair.
Primary alcohols are widely used in industry as solvents and precursors of detergents. The classic methods for hydration of terminal alkenes always produce the Markovnikov products. Herein, we reported a reliable approach to produce primary alcohols from terminal alkenes combining with biomass-derived allyl alcohol by tandem cross-metathesis/hydrogenation. A series of primary alcohol with different chain lengths was successfully produced in high yields (ca. 90%). Computational studies revealed that self-metathesis and hydrogenation of substrates are accessible but much slower than crossmetathesis. This new methodology represents a unique alternative to primary alcohols from terminal alkenes.