Efficient Optosensing of Hippuric Acid in the Undiluted Human Urine with Hydrophilic "Turn-On"-Type Fluorescent Hollow Molecularly Imprinted Polymer Microparticles.

The development of complex biological sample-compatible fluorescent molecularly imprinted polymers (MIPs) with improved performances is highly important for their real-world bioanalytical and biomedical applications. Herein, we report on the first hydrophilic "turn-on"-type fluorescent hollow MIP microparticles capable of directly, highly selectively, and rapidly optosensing hippuric acid (HA) in the undiluted human urine samples. These fluorescent hollow MIP microparticles were readily obtained through first the synthesis of core-shell-corona-structured nitrobenzoxadiazole (NBD)-labeled hydrophilic fluorescent MIP microspheres by performing one-pot surface-initiated atom transfer radical polymerization on the preformed "living" silica particles and subsequent removal of their silica core via hydrofluoric acid etching. They showed "turn-on" fluorescence and high optosensing selectivity and sensitivity toward HA in the artificial urine (the limit of detection = 0.097 µM) as well as outstanding photostability and reusability. Particularly, they exhibited much more stable aqueous dispersion ability, significantly faster optosensing kinetics, and higher optosensing sensitivity than their solid counterparts. They were also directly used for quantifying HA in the undiluted human urine with good recoveries (96.0%-102.0%) and high accuracy (RSD ≤ 4.0%), even in the presence of several analogues of HA. Such fluorescent hollow MIP microparticles hold much promise for rapid and accurate HA detection in the clinical diagnostic field.

Preparation of complex biological sample-compatible "turn-on"-type ratiometric fluorescent molecularly imprinted polymer microspheres via one-pot surface-initiated ATRP.

The efficient preparation of ratiometric fluorescent molecularly imprinted polymer (MIP) microspheres that can directly and selectively optosense a herbicide (i.e., 2,4-dichlorophenoxyacetic acid, 2,4-D) in undiluted pure milk is described. The dual fluorescent MIP microparticles were readily obtained through grafting a green 4-nitrobenzo[c][1,2,5]oxadiazole (NBD)-labeled 2,4-D-MIP layer with hydrophilic polymer brushes onto the preformed uniform "living" red CdTe quantum dot (QD)-labeled SiO2 microspheres via one-pot surface-initiated atom transfer radical polymerization (SI-ATRP) in the presence of a polyethylene glycol macro-ATRP initiator. They proved to be highly promising "turn-on"-type fluorescent chemosensors with red CdTe QD (the maximum emission wavelength λe,max around 710 nm) and green NBD (λe,max around 515 nm) as the reference fluorophore and "turn-on"-type responsive fluorophore, respectively. The sensors showed excellent photostability and reusability, high 2,4-D selectivity and sensitivity (the limit of detection = 0.12 µM), and direct visual detection ability (a fluorescent color change occurs from red to blue-green with the concentration of 2,4-D increasing from 0 to 100 µM) in pure bovine milk. The sensors were used for 2,4-D detection with high recoveries (96.0-104.0%) and accuracy (RSD ≤ 4.0%) in pure goat milk at three spiking levels of both 2,4-D and its mixtures with several analogues. This new strategy lays the foundation for efficiently developing diverse complex biological sample-compatible ratiometric fluorescent MIPs highly useful for real-world bioanalyses and diagnostics.

Biological sample-compatible Au nanoparticle-containing fluorescent molecularly imprinted polymer microspheres by combining RAFT polymerization and Au-thiol chemistry.

The development of biological sample-compatible fluorescent molecularly imprinted polymers (MIPs) with more functions and/or improved performance is of great importance for various bioanalytical and biomedical applications, but remains challenging. Herein, we report on a versatile strategy for preparing well-defined hydrophilic gold (Au) nanoparticle (AuNP)-containing fluorescent MIP microspheres capable of directly optosensing folic acid (FA) in undiluted urine samples and study of the effect of the incorporated AuNPs on their optosensing sensitivity. Such advanced functional fluorescent MIP particles were readily prepared by combining RAFT polymerization (including RAFT precipitation polymerization and surface-initiated RAFT polymerization) and Au-thiol chemistry [including successive attachment of AuNPs and a thiol-terminated poly(2-hydroxyethyl methacrylate) onto MIP particles after aminolysis of their surface dithioester into thiol groups]. They showed "turn-on" fluorescence and high optosensing selectivity and sensitivity toward FA in the undiluted urine sample (detection limit = 0.088 µM). They also exhibited outstanding photostability and reusability and could directly quantify FA in another undiluted urine sample with good recoveries (96.3-101.6%) and high accuracy (RSD = 0.6-3.1%), even in the presence of several interferents. Unfortunately, the incorporated AuNPs did not improve the optosensing sensitivity of AuNP-containing fluorescent MIPs. Nevertheless, introducing AuNPs onto the surfaces of fluorescent MIPs not only provides an effective new way for grafting with hydrophilic polymer brushes, but it also can endow them with certain new functions [e.g., surface-enhanced Raman scattering (SERS)], thus making them highly promising as both efficient optosensors and potential SERS sensors for rapid FA detection in applications such as clinical diagnostics and food analyses.

Auricular acupressure promotes uterine involution after cesarean section: A randomized controlled trial.

BACKGROUND: Postpartum subinvolution of the uterus is a more common condition after cesarean section. Auricular acupressure (AA) is widely used for the treatment of postpartum diseases. However, few studies have explored the effects of AA as a treatment of uterine involution following cesarean section to date. This study aimed to assess the efficacy and safety of AA for uterine involution after cesarean section. METHODS: A total of 109 women who underwent cesarean section participated in this study. They were randomly allocated to either real AA or sham AA in a 1:1 ratio by a computer program. For 3 days, the real AA and sham AA groups received treatment 3 times daily. A series of assessments at 42 days after cesarean section, namely on the uterine size, the incidence of hydrometra, the first anal exsufflation time, bleeding volume at 6 hours, bleeding volume at 6-24 hours along with other general assessments were carried out. RESULTS: A total of 89 women completed the study. The uterine size at 42 days after a cesarean section was 6.3 cm smaller in the real AA group than in the sham AA group (P < 0.01). The incidence of hydrometra on day 42 postpartum was lower in the real AA group than in the sham AA group (P < 0.01). The lochia duration and the first anal exsufflation time after cesarean section were shorter in the real AA group than in the sham AA group (P < 0.05). CONCLUSION: AA improves uterine involution after cesarean section. TRIAL REGISTRATION: ChiCTR1800015569.

Photochemical degradation kinetics and mechanism of short-chain chlorinated paraffins in aqueous solution: A case of 1-chlorodecane.

Short chain chlorinated paraffins (SCCPs) have attracted worldwide attention in recent years, due to their high production volume, persistent, bioaccumulative and toxic properties. In this study, 1-chlorodecane (CD) was selected as a model of SCCPs to explore its photochemical degradation behavior under UV irradiation. The results found that CD could be completely photochemical degradation within 120 min, and the •OH was found to be the main reactive species from both quenching experiments and electron paramagnetic resonance (EPR) results. However, the contribution of triple excited state of CD (3CD*) was still nonnegligible from the results with the absorption peak at 480 nm obtained by laser flash photolysis. Based on the identified intermediates as well as the data from theoretical chemical calculation, the detailed photochemical degradation mechanism of CD was tentatively proposed that CD firstly was excited and photo-ionized under UV irradiation, and the released Cl• in water could result in generating •OH. Then •OH initiates CD degradation mainly through the H-abstraction pathway, leading to the generation of several dehydrogenation radicals, which further generated alcohols or long chain intermediates through radical-radical reactions. The results will provide a comprehensive understanding of the degradation mechanism and environmental fates of SCCPs in water under UV irradiation.