Chronoamperometry was used to study the dynamics of Pt nanoparticle (NP) collision with an inert ultramicroelectrode via electrocatalytic amplification (ECA) in the hydrogen evolution reaction. ECA ...and dynamic light scattering (DLS) results reveal that the NP colloid remains stable only at low proton concentrations (1.0 mm) under a helium (He) atmosphere, ensuring that the collision events occur at genuinely single NP level. Amperometry of single NP collisions under a He atmosphere shows that each discrete current profile of the collision event evolves from spike to staircase at more negative potentials, while a staircase response is observed at all of the applied potentials under hydrogen‐containing atmospheres. The particle size distribution estimated from the diffusion‐controlled current in He agrees well with electron microscopy and DLS observations. These results shed light on the interfacial dynamics of the single nanoparticle collision electrochemistry.
Evolution or stability? Under a helium atmosphere, the electrochemical catalytic current profile of the hydrogen evolution reaction on a single platinum nanoparticle (Pt NP) evolves from a spike to a staircase at more negative potentials on the underlying inert ultramicroelectrode (UME). Under a hydrogen atmosphere, the current profile stabilizes as a staircase at all polarized potentials but at least 5 times lower than that in helium.
Progesterone is required for the establishment and maintenance of mammalian pregnancy and widely used for conservative treatment of luteal phase deficiency in clinics. However, there are limited ...solid evidences available for the optimal timing and dose of progesterone therapy, especially for the possible adverse effects on implantation and decidualization when progesterone is administrated empirically. In our study, mouse models were used to examine effects of excess progesterone on embryo implantation and decidualization. Our data indicate that excess progesterone is not only harmful for mouse implantation, but also impairs mouse decidualization. In excess progesterone-treated mice, the impaired LIF/STAT3 pathway and dysregulated endoplasmic reticulum stress may lead to the inhibition of embryo implantation and decidualization. It is possible that the decrease in birth weight of excess progesterone-treated mice is due to a compromised embryo implantation and decidualization. Furthermore, excess progesterone compromises in vitro decidualization of human endometrial stromal cells.
The zinc-bromine flow battery (ZBFB) is one of the most promising technologies for large-scale energy storage. Here, nitrogen-doped carbon is synthesized and investigated as the positive electrode ...material in ZBFBs. The synthesis includes the carbonization of the glucose precursor and nitrogen doping by etching in ammonia gas. Physicochemical characterizations reveal that the resultant carbon exhibits high electronic conductivity, large specific surface area, and abundant heteroatom-containing functional groups, which benefit the formation and exposure of the active sites toward the Br
/Br
redox couple. As a result, the assembled ZBFB achieves a voltage efficiency of 83.0% and an energy efficiency of 82.5% at a current density of 80 mA cm
, which are among the top values in literature. Finally, the ZBFB does not yield any detectable degradation in performance after a 200-cycle charging/discharging test, revealing its high stability. In summary, this work provides a highly efficient electrode material for the zinc-bromine flow battery.
Promoters are DNA regulatory elements located directly upstream or at the 5' end of the transcription initiation site (TSS), which are in charge of gene transcription initiation. With the completion ...of a large number of microorganism genomics, it is urgent to predict promoters accurately in bacteria by using the computational method. In this work, a sequence-based predictor named "iPro70-PseZNC" was designed for identifying sigma70 promoters in prokaryote. In the predictor, the samples of DNA sequences are formulated by a novel pseudo nucleotide composition, called PseZNC, into which the multi-window Z-curve composition and six local DNA structural properties are incorporated. In the 5-fold cross-validation, the area under the curve of receiver operating characteristic of 0.909 was obtained on our benchmark dataset, indicating that the proposed predictor is promising and will provide an important guide in this area. Further studies showed that the performance of PseZNC is better than it of multi-window Z-curve composition. For the sake of convenience for researchers, a user-friendly online service was established and can be freely accessible at http://lin.uestc.edu.cn/server/iPro70-PseZNC. The PseZNC approach can be also extended to other DNA-related problems.
•MIPs/CDs grafted paper-based sensor for selective and sensitive determination of 3-MCPD.•CDs were intercepted in the paper and MIPs was also directly formed on the paper-based sensor.•The composites ...exhibited high adsorption capacity and excellent selectivity.•This method could be applied for the detection of 3-MCPD in soy sauce samples.
3-Monochloropropane-1,2-diol (3-MCPD) is a common food processing contaminant and a simple, rapid, sensitive and low cost monitoring technology is needed due to its potential carcinogenic nature. Carbon dots directly intercepted on filter paper provide high fluorescence intensity and can be adapted for use as a sensor. We synthesized a carbon dot-filter paper in combination with a molecularly imprinted polymeric film to extract 3-MCPD from samples. This grafted paper-based sensor exhibited a high adsorption capacity (68.97 mg g−1), an excellent selectivity (imprinting factor = 4.5) and a low detection limit (0.6 ng mL−1). Recoveries ranged from 97.2% to 105.3% with relative standard deviations <5.6%. The results obtained using this method were linearly correlated to those of the classic GC–MS method (r = 0.998). Based on the Chinese National Standard, this study provides a novel and powerful platform for the simple, rapid, sensitive and on-site analysis of 3-MCPD in soy sauce.
Direct myocardial and vascular injuries due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven inflammation is the leading cause of acute cardiac injury associated with ...coronavirus disease 2019 (COVID-19). However, in-depth knowledge of the injury characteristics of the heart affected by inflammation is lacking. In this study, using a quantitative spatial proteomics strategy that combines comparative anatomy, laser-capture microdissection, and histological examination, we establish a region-resolved proteome map of the myocardia and microvessels with obvious inflammatory cells from hearts of patients with COVID-19. A series of molecular dysfunctions of myocardia and microvessels is observed in different cardiac regions. The myocardia and microvessels of the left atrial are the most susceptible to virus infection and inflammatory storm, suggesting more attention should be paid to the lesion and treatment of these two parts. These results can guide in improving clinical treatments for cardiovascular diseases associated with COVID-19.
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•Spatial proteome maps of COVID-19 myocardia and microvessels are established•SARS-CoV-2-driven inflammation leads to region-resolved dysfunction of the heart•Mechanisms of dysregulated contraction, conduction, and circulation are elaborated•Myocardia and microvessels of the left atrium are affected by inflammation the most
Leng et al. establish a region-resolved proteome map of the inflammatory myocardia and microvessels of COVID-19 hearts. The myocardia and microvessels of the left atrium are the most affected by inflammation storm. These results could provide guidance in improvement of clinical treatments for cardiovascular diseases associated with COVID-19.
Abstract
Although chirality is an ever-present characteristic in biology and some artificial molecules, controlling the chirality and demystifying the chirality origin of complex assemblies remain ...challenging. Herein, we report two homochiral Ag
14
nanoclusters with inherent chirality originated from identical rotation of six square faces on a Ag
8
cube driven by intra-cluster π···π stacking interaction between pntp
−
(Hpntp =
p-
nitrothiophenol) ligands. The spontaneous resolution of the racemic (SD/
rac
-Ag14a) to homochiral nanoclusters (SD/
L
-Ag14 and SD/
R
-Ag14) can be realized by re-crystallizing SD/
rac
-Ag14a in acetonitrile, which promotes the homochiral crystallization in solid state by forming C–H···O/N hydrogen bonds with nitro oxygen atoms in pntp
−
or aromatic hydrogen atoms in dpph (dpph = 1,6-bis(diphenylphosphino)hexane) on Ag
14
nanocluster. This work not only provides strategic guidance for the syntheses of chiral silver nanoclusters in an all-achiral environment, but also deciphers the origin of chirality at molecular level by identifying the special effects of intra- and inter-cluster supramolecular interactions.
Kinetically stable and long‐lived intermediates are crucial in monitoring the progress and understanding of supramolecular self‐assembly of diverse aggregated structures with collective functions. ...Herein, the complex dynamics of an atomically precise CuI nanocluster Cu8(tBuC6H4S)8(PPh3)4 (Cu8a) is systematically investigated. Remarkably, by monitoring the aggregation‐induced emission (AIE) and electron microscopy of the kinetically stable intermediates in real time, the directed self‐assembly (DSA) process of Cu8a is deduced. The polymorphism and different emission properties of Cu NCs aggregates were successfully captured, allowing the structure–optical property relationship to be established. More importantly, the utilization of a mathematical “permutation and combination” ideology by introducing a heterogeneous luminescent agent of a carbon dot (CD) to Cu8a aggregates enriches the “visualization” fluorescence window, which offers great potential in real time application for optical sensing of materials.
Within the scheme of aggregation‐induced emission (AIE), optical‐engineering was performed for real‐time monitoring of the self‐assembly process of Cu8a with various kinetic long‐lived intermediates, leading to a structure–property relationship being established.
Optimal vision and ergonomics are essential factors contributing to the achievement of good results during microsurgery. The three-dimensional (3D) digital image microscope system with a better 3D ...depth of field can release strain on the surgeon's neck and back, which can improve outcomes in microsurgery. We report a randomized prospective study of vasoepididymostomy and vasovasostomy using a 3D digital image microscope system (3D-DIM) in rats. A total of 16 adult male rats were randomly divided into two groups of 8 each: the standard operating microscope (SOM) group and the 3D-DIM group. The outcomes measured included the operative time, real-time postoperative mechanical patency, and anastomosis leakage. Furthermore, a user-friendly microscope score was designed to evaluate the ergonomic design and equipment characteristics of the microscope. There were no differences in operative time between the two groups. The real-time postoperative mechanical patency rates were 100.0% for both groups. The percentage of vasoepididymostomy anastomosis leakage was 16.7% in the SOM group and 25.0% in the 3D-DIM group; however, no vasovasostomy anastomosis leakage was found in either group. In terms of the ergonomic design, the 3D-DIM group obtained better scores based on the surgeon's feelings; in terms of the equipment characteristics, the 3D-DIM group had lower scores for clarity and higher scores for flexibility and adaptivity. Based on our randomized prospective study in a rat model, we believe that the 3D-DIM can improve surgeon comfort without compromising outcomes in male infertility reconstructive microsurgery, so the 3D-DIM might be widely used in the future.
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