Latest ArticlesComputed tomography (CT) is one of the most commonly used non-invasive clinical imaging modalities to predict, diagnose and treat the disease. Iodinated contrast media (ICM) is a form of intravenous radiocontrast agent containing iodine, which enhances the visibility of hollow tissue structures in medical CT imaging. ICM may cause allergic reactions, contrast-induced nephropathy, hyperthyroidism and possibly metformin accumulation. It is significant to find out the risk factors, pathogenesis, diagnosis, prevention, and treatment of adverse reactions caused by ICM. Revealing the changes of the lipid droplets (LDs) viscosity in pathophysiological processes such as cancer and iodined contrast media induced adverse reaction is not only important for monitoring the occurrence and development of some pathophysiological processes but also vital for the deep insight of the biological effects of LDs in these pathophysiological processes. A lipid droplets targeted fluorescent probe DN-1 was devised to sense cellular viscosity alteration with high selectivity and sensitivity, which was applied to distinguish cancer cells and normal cells and reveal viscosity changes during iodined CT contrast media treatment.
The effective materials and methods for detection and separation of pesticides are urgently needed because most of pesticides show very harmful influence on life and environment. As a new kind of macrocyclic host compound, pillar[n]arenes show very good performance in the detection and separation of pesticides, especially for paraquat (PQ). For the pesticide detection and separation materials, their structures determine performance. Therefore, this review summarizes the recent progress of pillar[n]arenes-based materials for detection and separation of pesticides covering single/multi-pillar[n]arenes, pillar[n]arenes-based polymers, frameworks, composites, nanomaterials, etc. The structure-performance relationships of these materials have been discussed according to the cavity size, the synergistic or collaboration effect, the structure of the polymer or framework, the substrate of the composites and the size of nanomaterials and so on. Based on these, we also look forward to the future and point out the possible way for improving the pesticides detection sensitivity and separation efficiency of this kind of materials.
The transformation of a Palladium-based metal-organic cage to a structurally similar one by direct ligand replacement usually leads to unwanted ligand scrambling. In this work, an intermediate ligand with different shape and basicity from the initial/final ones was introduced to avoid ligand scrambling to achieve the efficient indirect cage-to-similar-cage transformation. Compared with the direct transformation, the stepwise conversion has the advantages of high efficiency (93%) and simple workup.
Available online Iodinated X-ray contrast media (ICMs) are clinical drugs used to enhance the imaging effect. Triiodobenzene ring structures of ICMs lead to its extremely high chemical stability, biological inertness, which makes it difficult to be completely removed by traditional water treatment processes. Hence, considerable concentration of ICMs can be frequently detected in aquatic environment. Relying on the strong oxidation capacity of HO• or SO4•‒, various advanced oxidation processes (AOPs) have demonstrated substantial removal efficiency for ICMs. It is evident that ICMs can be decomposed mainly through (1) deiodination, (2) dehydration, (3) decarboxylation, (4) H-abstraction, (5) hydroxyl addition, (6) hydroxyl substitution, (7) oxidation of alcohol groups, (8) cleavage of amide bond, and (9) amino oxidation. However, during the ICMs removal process, the C-I bonds of ICMs molecules are broken, giving rise to the formation of cytotoxic iodination disinfection by-products (I-DBPs) that are potentially more harmful to the ecosystem and human health than their parent compounds. To better understand the technology gaps, this review elaborates the major AOPs which are effective for ICMs removal and emphasizes on the main degradation routes of ICMs in different oxidation system. Some prevailing concerns and challenges are discussed for optimizing the ICMs treatment process.
Recent developments in the utilization of microfluidic chips (MFCs) have shown their potential utility in multiphase organic synthesis by enabling efficient organic reactions in flow chemistry. However, MFCs technology has been wandering in the laboratory of small dose synthetic routes, which is limited to the level of "tiny" fluid flux. To address this issue, we herein report the first case of the chips with high-throughput 3D channels produced by femtosecond laser being used to create a time-saving, cost-effective and risk-free approach suitable for large-scale flow synthesis. Several multiphase reactions have been successfully prepared on demand in our designed flow synthesis system containing 3D MFCs: 1) benzyl alcohol was converted to benzaldehyde in 3 min with a yield of 97.50% by liquid-liquid two-phase transfer catalytic oxidation; 2) organozinc reagents and α-cyano carbonyl carbon compounds were synthesized by solid-liquid two-phase metal insertion reaction in 7 min, and the yield was up to 100%; 3) benzoic acid was synthesized by gas-liquid two-phase carboxylation reaction in 2.8 s with a yield of 96%. Significant gains in production rate result from the effective scaling of flow reactors from microliters per hour in MFCs to intermediate milliliters per minute without affecting mass transport performance. Meanwhile, our 3D MFCs show excellent mass and heat transfer efficiency in large-scale industrial units, breaking through the bottleneck in this field. As a result, it is possible to imagine the creation of a new, streamlined flow synthetic technique via MFCs for green multiphase organic synthesis.
The clinical efficacy of chemotherapeutic drugs is hindered by their poor aqueous solubility, low bioavailability and severe side effects. In recent years, polymeric nanocarriers have been used for drug delivery to improve the efficacy of many chemotherapeutics. In this study, a series of biodegradable phenylalanine-based poly(ester amide) (Phe-PEA) with tunable molecular weights (MWs) were synthesized to systematically investigate the relationship between the polymer MW and the efficacy of the corresponding polymeric nanoparticles (NPs). The results indicated that a range of polymers with different MWs can be obtained by varying the monomer ratio or reaction time. Doxorubicin (DOX), a classic clinical lymphoma treatment strategy, was selected as a model drug. The loading capacity and stability of the higher MW polymeric NPs were superior to those of the lower MW ones. Moreover, in vitro and in vivo data revealed that high MW polymeric NPs had better anticancer efficacy against lymphoma and higher biosafety than low MW polymeric nanoparticles and DOX. Therefore, this study suggests the importance of polymer MW for drug delivery systems and provides valuable guidance for the design of enhanced polymeric drug carriers for lymphoma treatment.
Chalcogenative sulfones (thiosulfonates and selenosulfonates), as reactants for organic transformations, are widely used and interesting because of their potential to react with nucleophiles, electrophiles, and free radicals. As stable radical reagents, the synthesis and applications of chalcogenative sulfones have opened up a novel pathway to synthesize many kinds of compounds containing sulfur or selenium motifs. However, despite the numerous recent works on the synthesis and applications of thiosulfonates and selenosulfonates as radical reagents, no review has yet provided a summary of the literature. In this paper, we aim to review the synthesis and applications strategies of chalcogenative sulfones as radical reagents reported over the past several decades. Different types of catalysis are discussed in this review: (ⅰ) metal catalysis; (ⅱ) visible-light catalysis; (ⅲ) synergistic catalysis; and (ⅲⅰ) other types. Concurrently, in visible-light catalysis and metallaphotoredox catalysis sections, we highlight that developing relatively environmentally friendly synthetic methods in this area is always a great challenge, but also a persistent pursuit. Finally, the scopes, limitations, mechanisms, and existing problems of some reactions are described briefly.
Fatty acid photodecarboxylase of Chlorella variabilis NC64A (CvFAP) is a novel photoenzyme with great potential in the treatment of waste lipids and production of sustainable aviation fuel. However, the fragile nature of CvFAP to blue light is an urgent challenge. Herein, we demonstrated anaerobic environment could significantly improve the photostability of CvFAP for the first time. The decarboxylation of palmitic acid by CvFAP for 3 h under anaerobic environment increased pentadecane yield by 44.7% as compared to that under aerobic environment. The residual activity of CvFAP after blue-light preillumination in the absence of palmitic acid for 0.5 h under anaerobic environment was 80.4%, which was 258.7 times higher than that under aerobic environment. Remarkable accumulation of superoxide radical and singlet oxygen in CvFAP under aerobic environment led to the poor photostability of CvFAP. Anaerobic environment helped to mitigate the production of superoxide radical and singlet oxygen in CvFAP, improving the photostability of CvFAP.
Removal and recovery of phosphorus (P) from wastewater is of great importance to addressing the challenges of eutrophication and phosphorus shortage. The P removal and recovery performance of conventional electrochemical precipitation approach was constrained by the limited mass transfer rate. Herein, a cathodic membrane filtration (CMF) reactor was developed using Ti/SnO2-Sb anode and titanium mesh cathodic membrane module to achieve efficient removal and recovery of P in wastewater. Compared with the flow-by mode, the CMF system in the flow-through mode exhibited excellent P removal performance due to the markedly enhanced mass transfer. At the current density of 4 A/m2, membrane flux of 16.6 L m−2 h−1, and Ca/P molar ratio of 1.67, the removal efficiency of P was 96.2% and the energy consumption was only 45.7 kWh/kg P. The local high pH of cathode surface played a vital role in P removal, which substantially accelerated the nucleation of calcium phosphate (CaP). Based on the crystalline and morphological characterization of the precipitates, the hydroxyapatite was the most stable crystalline phase of CaP, which was transformed from intermediate phases (such as dicalcium phosphate and amorphous calcium phosphate). This study paves the way for applying electrochemical membrane filtration system for P removal and recovery from wastewater.