Pt Nanoparticles Confined in a 3D Porous FeNC Matrix as Efficient Catalysts for Rechargeable Li-CO2/O2 Batteries.

The cathodic product Li2CO3, due to its high decomposition potential, has hindered the practical application of rechargeable Li-CO2/O2 batteries. To overcome this bottleneck, a Pt/FeNC cathodic catalyst is fabricated by dispersing Pt nanoparticles (NPs) with a uniform size of 2.4 nm and 8.3 wt % loading amount into a porous microcube FeNC support for high-performance rechargeable Li-CO2/O2 batteries. The FeNC matrix is composed of numerous two-dimensional (2D) carbon nanosheets, which is derived from an Fe-doping zinc metal-organic framework (Zn-MOF). Importantly, using Pt/FeNC as the cathodic catalyst, the Li-CO2/O2 (VCO2/VO2 = 4:1) battery displays the lowest overpotential of 0.54 V and a long-term stability of 142 cycles, which is superior to batteries with FeNC (1.67 V, 47 cycles) and NC (1.87 V, 23 cycles) catalysts. The FeNC matrix and Pt NPs can exert a synergetic effect to decrease the decomposition potential of Li2CO3 and thus enhance the battery performance. In situ Fourier transform infrared (FTIR) spectroscopy further confirms that Li2CO3 can be completely decomposed under a low potential of 3.3 V using the Pt/FeNC catalyst. Impressively, Li2CO3 exhibits a film structure on the surface of the Pt/FeNC catalysts by scanning electron microscopy (SEM), and its size can be limited by the confined space between the carbon sheets in Pt/FeNC, which enlarges the better contacting interface. In addition, density functional theory (DFT) calculations reveal that the Pt and FeNC catalysts show a higher adsorption energy for Li2CO3 and Li2CO4 intermediates compared to the NC catalyst, and the possible discharge pathways are deeply investigated. The synergetic effect between the FeNC support and Pt active sites makes the Li-CO2/O2 battery achieve optimal performance.

Construction of PEGylated boronate-affinity-oriented imprinting magnetic nanoparticles for ultrasensitive detection of ellagic acid from beverages.

Molecularly imprinted polymers (MIPs) can exhibit antibody-level affinity for target molecules. However, the nonspecific adsorption of non-imprinted regions for non-target molecules limits the application range of MIPs. Herein, we fabricated PEGylated boronate-affinity-oriented ellagic acid-imprinting magnetic nanoparticles (PBEMN), which first integrated boronate-affinity-oriented surface imprinting and sequential PEGylation for small molecule-imprinted MIPs. The resultant PBEMN possess higher adsorption capacity and faster adsorption rate for template ellagic acid (EA) molecules than the non-PEGylated control. To prove the excellent performance, the PBEMN were linked with hydrophilic boronic acid-modified/fluorescein isothiocyanate-loaded graphene oxide (BFGO), because BFGO could selectively label cis-diol-containing substances by boronate-affinity and output ultrasensitive fluorescent signals. Based on a dual boronate-affinity synergy, the PBEMN first selectively captured EA molecules by boronate-affinity-oriented molecular imprinted recognition, and then the EA molecules were further labeled with BFGO through boronate-affinity. The PBEMN linked BFGO (PBPF) strategy provided ultrahigh sensitivity for EA molecules with a limit of detection of 39.1 fg mL-1, resulting from the low nonspecific adsorption of PBEMN and the ultrasensitive fluorescence signal of BFGO. Lastly, the PBPF strategy was successfully employed in the determination of EA concentration in a spiked beverage sample with recovery and relative standard deviation in the range of 96.5 to 104.2% and 3.8 to 5.1%, respectively. This work demonstrates that the integration of boronate-affinity-oriented surface imprinting and sequential PEGylation may be a universal tool for improving the performance of MIPs.

Hydrophilic rhodamine B-loaded / boronic acid-modified graphene oxide nanocomposite as a substitute of enzyme-labeled second antibody for ultrasensitive detection of antibodies.

Enzyme-labeled secondary antibody is often used to amplify the output signal in the process of antibody detection. However, its preparation process is complex and time-consuming. Herein, we fabricated an innovative hydrophilic rhodamine B-loaded / boronic acid-modified graphene oxide (HRBGO) nanocomposite, used as a substitute of enzyme-labeled second antibody. The synthetic HRBGO was loaded with generous rhodamine B and modified with boronic acid. Therefore, the HRBGO could selectively label the carbohydrate chains of Fc fragment of primary antibody through specific boronate affinity recognition, and then perform signal output and amplification by releasing rhodamine B. To verify the practicability of HRBGO, trastuzumab as a humanized monoclonal antibody targeting human epidermal growth factor receptor-2 (HER2) was selected as model antibody. A glycosylation site-blocked / HER2-immobilized magnetic nanoparticles (GHMN) was also prepared for selectively capturing trastuzumab from complex samples via specific immunoaffinity. Because the glycosylation sites of HER2 can also be labeled with the HRBGO by boronate affinity recognition, these sites were blocked by a masking agent to minimize the background signal. For specific and ultrasensitive detection of trastuzumab, the integration of GHMN and HRBGO was proposed and optimized in detail. Trastuzumab detection based on HRBGO consisted of three steps: specific capture, selective labeling, and output signal. The proposed strategy provided ultrahigh sensitivity with limit of detection of 0.35 fg mL-1 and was successfully applied in the detection of trastuzumab in spiked serum sample with recovery and relative standard deviation in the range of 98.7-103.8% and 3.8-6.0%, respectively. To assess universal applicability, the HRBGO was also successfully used for the determination of anti-SARS-COV2 RBD antibody in human serum sample.

Preparation of teamed boronate affinity magnetic nanoparticles for extraction of polyphenols from Flos Lonicerae Beverage under neutral pH prior to their determination by high-performance liquid chromatography-mass spectrometry.

Traditional boron affinity materials usually capture cis-diol-containing molecules under alkaline condition, but some cis-diol-containing molecules, such as polyphenols, are unstable and easy to be oxidized and degraded under alkaline condition. Teamed boronate affinity (TBA) can specifically capture cis-diol-containing molecules under neutral condition. However, the report about combination of TBA and magnetic nanoparticle for the extraction was rare. Here, we fabricated two kinds of teamed boronate affinity magnetic nanoparticles (TBAMP), including Fe3O4@TBAP and Fe3O4@SiO2@TBAP. Adsorption capacities of cis-diol-containing molecules on the latter were similar to these on the former, but the latter possessed more superior regeneration performance than the former. Therefore, the TBAMP with more superior regeneration performance was used as magnetic solid-phase extraction (MSPE) adsorbent for capturing polyphenols under neutral condition. The TBAMP MSPE was optimized in detail, and combined with high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the simultaneous determination of 13 kinds of polyphenols from Flos Lonicerae Beverage. The proposed method showed low limit of detection between 0.01 and 0.20 ng mL-1. In blank Flos Lonicerae Beverage, 11 kinds of polyphenols ranged from 0.54 ng mL-1 to 52.99 ng mL-1 were detected. In the standard addition method, recoveries of cis-diol-containing polyphenols were between 85.7% and 102.1% with intra-day and inter-day relative standard deviation ranging from 3.2% to 5.1% and 5.3% to 7.3%, respectively.

Synthesis of multirecognition magnetic molecularly imprinted polymer by atom transfer radical polymerization and its application in magnetic solid-phase extraction.

In this work, we reported an effective method for the synthesis of a multirecognition magnetic molecularly imprinted polymer (MMIP) with atom transfer radical polymerization (ATRP), using 2,4-diamino-6-methyl-1,3,5-triazine as pseudo-template. The resulting MMIP was characterized in detail by Fourier transform-infrared (FT-IR) spectra, scanning electron microscopy (SEM), thermogravimetic analysis (TGA), and vibrating sample magnetometry (VSM). These results indicated the successful synthesis of MMIP with sufficient thermal stability and magnetic properties. The adsorption experiments were carried out to evaluate the specific selectivity of MMIP related to the spatial structure of target molecules. The MMIP exhibited multirecognition ability and excellent binding capability for melamine (MEL), cyromazine (CYR), triamterene (TAT), diaveridine (DVD), and trimethoprim (TME), and the apparent maximum number of binding sites (Q max) was 77.5, 75.2, 72.5, 69.9, and 70.4 µmol g-1, respectively. The multirecognition MMIP not only possessed adequate magnetic responsiveness for fast separation but also avoided the risk of template leakage on trace component analysis. Therefore, it was suitable for serving as a magnetic solid-phase extraction (MSPE) adsorbent. MSPE coupled with high-performance liquid chromatography analysis was applied to enrich and separate five target molecules from three samples. Recoveries for all target molecules ranged from 81.6 to 91.5% with relative standard deviations of no more than 4.1% (n = 3). Graphical abstract Multirecognition property of magnetic molecularly imprinted polymer prepared with pseudo template.

Field redistribution inside an X-ray cavity-QED setup.

The field redistribution inside an X-ray cavity-QED setup with an embedded 57Fe layer is calculated and studied in detail. The destructive interference between two transitions from the ground state to the two upper dressed states causes that the cavity mode can not be driven. So the field intensity is very weak when the nuclear ensemble is resonant. Moreover, It is found that the resonant nuclear layer can play a role of reflective layer like a mirror and cut the size of the cavity, which will destroy the guided mode. To support this idea, we employ the 57Fe film as the bottom mirror layer of the cavity where a guided mode can only be formed at the resonant energy. Following this perspective, the electromagnetically induced transparency structure based on X-ray cavity-QED setup with nuclear ensemble is reviewed and a phenomenologically self-consistent analysis for the field redistribution is presented.

Crystal Structure, Cytotoxicity and Interaction with DNA of Zinc (II) Complexes with o-Vanillin Schiff Base Ligands.

Two new zinc complexes, Zn(HL1)2 (1) and [Zn2(H2L2)(OAc)2]2 (2) [H2L1 = Schiff base derived from o-vanillin and (R)-(+)-2-amino-3-phenyl-1-propanol, H3L2 = Schiff base derived from o-vanillin and 2-amino-2-ethyl-1,3-propanediol], have been synthesized and characterized by single crystal X-ray diffraction, elemental analyses, TG analyses, solid fluorescence, IR, UV-Vis and circular dichroism spectra. The structural analysis shows that complex 1 has a right-handed double helical chain along the crystallographic b axis. A homochiral 3D supramolecular architecture has been further constructed by intermolecular C-H··· π, O-H···O and C-H···O interactions. Complex 2 includes two crystallographically independent binuclear zinc molecules. The two binuclear zinc molecules are isostructural. The 2-D sheet supramolecular structure was formed by intermolecular hydrogen bonding interaction. The fluorescence of ligands and complexes in DMF at room temperature are studied. The interactions of two complexes with calf thymus DNA (CT-DNA) are investigated using UV-Vis, CD and fluorescence spectroscopy. The results show that complex 1 exhibits higher interaction with CT-DNA than complex 2. In addition, in vitro cytotoxicity of the complexes towards four kinds of cancerous cell lines (A549, HeLa, HL-60 and K562) were assayed by the MTT method. Investigations on the structures indicated that the chirality and nuclearity of zinc complexes play an important role on cytotoxic activity.

Hemoglobin H disease in Guangxi province, Southern China: clinical review of 357 patients.

The clinical characteristics of 357 patients with hemoglobin H (HbH) disease from the Guangxi province of Southern China were studied. One hundred and ninety-one (53.3%) patients were diagnosed with HbH-Constant Spring, 19 were diagnosed with HbH Westmead. Ten patients were shown to have coinherited HbH-Constant Spring/QS with a ß-thalassemia mutation. Coinheritance of the ß-thalassemia gene does not alleviate anemia (8.2 ± 2.3 vs. 7.6 ± 1.7 g/dl, p = 0.276), or influence age at diagnosis (20.2 ± 19.6 vs. 12.9 ± 11.0 years, p = 0.276). Ferritin levels were significantly higher in the group of patients with the nondeletional form of the disease (475 ± 719 vs. 249 ± 264 ng/ml, p = 0.005).

[Electronic regulation mode on implantable medical device].

OBJECTIVE: To discuss the methods of implantable medical device supervision reform. METHODS: Methods of literature review, comparative study, the research of situation, developmental study and case study were adopted. RESULTS: It is the untrue and asymmetric information of implantable medical device that results in improper behavior in the implantable medical device industry. CONCLUSIONS: A implantable medical device electronic monitoring system, namely establishing the independent but interrelated real-time dynamic updating of the databases, which would guarantee the information of implantable medical device is open and transparent, eliminate false food information transmission, vindicate the good order of domestic implantable medical device industry and protect the vital interests of the public.