Treatment and nursing values of a new mixed-ligand In(III)-based complex on acute ischemic stroke

In the current research, through employing the dual ligand method, a novel coordination polymer has been produced in success via the reaction between H₂glu and In(NO₃)₃·6H₂O in the existence of the nitrogen-donor chelating 2,2′-bpy ligand in CH₃CN In(III) and DMF mixed solvent, and its chemical formula is In(glu)(Hglu)(2,2′-bpy) (1, 2,2′-bpy is 2,2′-bipyridine and H₂glu is glutaric acid). Its application values on the acute stroke were assessed and the corresponding mechanism was investigated simultaneously. Firstly, the levels of inflammatory response in the astrocytes were evaluated by ELISA by measuring the content of inflammatory cytokines released into cerebrospinal fluid. Additionally, the miRNA199a relative expression levels in astrocytes were measured via exploiting real time RT-PCR. Molecular docking simulation demonstrated that synthesized In ion complex exhibited excellent biological activities, multiple binding interactions were formed by the carboxyl groups on the In ion complex.     

槲皮素-3-O-丙基衍生物的合成及生物活性研究

槲皮素是具有丰富生物活性的黄酮类化合物,药理活性显著。本文以槲皮素为先导物,选择性对C环3位羟基进行修饰,以廉价的芦丁为原料,经苄基保护、Williamson成醚反应,再经Pd/C催化加氢脱苄基得到28个未见文献报道的槲皮素-3-O-丙基衍生物,其结构经¹H NMR、¹³C NMR、ESI-MS进行确证。采用MTT法考察了所合成化合物对人食管鳞癌（EC109）、人胃癌（HGC27）、人乳腺癌（MCF-7）、小鼠黑色素瘤（B16-F10）的增殖抑制作用。结果显示,通过化学方法对槲皮素结构进行修饰后,其体外抗肿瘤活性增强。其中,化合物F3(IC₅₀=5.23±0.37μmol/L)、F5(IC₅₀=2.63±0.09μmol/L)对小鼠黑色素瘤（B16-F10）抑制作用比5-氟尿嘧啶(IC₅₀=14.38±0.27μmol/L)好,值得进一步研究。     

A Porphyrin-Based Covalent Organic Framework for Metal-Free Photocatalytic Aerobic Oxidative Coupling of Amines

Imines are important intermediates in drug synthesis. Photocatalytic aerobic oxidative coupling of amines has been considered as a clean and promising way to produce imines and has attracted great attention. Herein, we designed and synthesized a novel two-dimensional porphyrin-based covalent organic framework (Por-BC-COF) which adopts an AA stacking mode with excellent crystallinity, high Brunauer–Emmett–Teller surface areas (1200 m² g⁻¹), wide light absorption range (200–1300 nm) and good stability in a variety of organic solvents. Por-BC-COF can be used as a metal-free heterogeneous photocatalyst for the photocatalytic oxidation of amines to imines under visible light and red light with a high yield (97 %). This work presents a novel and efficient COF photocatalyst in the application of light-driven organic synthesis.     

Conductive 2D Metal-organic Framework (Co,NiCo, Ni) Nanosheets for Enhanced Non-enzymatic Detection of Urea

2D metal-organic framework (MOF) has potential applications in electrocatalysis owing to fast mass transfer, charge transfer and large specific surface area. Here, we had prepared three conductive 2D MOF based on Ni, NiCo and Co in a simple and rapid way. The 2D nanostructure of MOF was confirmed by SEM and TEM. The chemical composition was studied by XRD, Raman and XPS spectrum. The electrochemical oxidation and detection was investigated through cyclic voltammetry and current-time method. Their sensing performance for urea was determined by varying oxidation potentials and metal sites. The non-enzymatic Ni-, NiCo- and Co-MOF sensors had good catalytic activity for urea. Compared with NiCo- and Co-MOF, Ni-MOF had a wider linear range (0.5–832.5 μM), high sensitivity (1960 μA mM⁻¹ cm⁻²), low detection limit (0.471 μM), and fast response time. The sensors had well repeatability, reproducibility, and selectivity to specific interfering species. Furthermore, Ni- and NiCo-MOF modified electrode was also applied to detection of milk samples. The results showed that the recovery was satisfactory, which further confirmed the effectiveness of non-enzyme sensor. In general, the highly-sensitive 2D Ni- and NiCo-MOF modified electrode has great potential as nonenzymatic urea sensors for real samples detection in hydrogen energy, clinical diagnostics, and environmental protection, et al.     

Co_2Fe(μ_3-S)(CO)_7(CH_3CSNH)的合成与结构

用Co2（CO）8与CH3CSNH2反应制得产物Ⅰ，又用Na2Fe（CO）4与Ⅰ反应制得产物Ⅱ（Ⅰ：Co3（μ3－S）（CO）7（CH3CSNH），Ⅱ：Co2Fe（μ3-S）（CO）7（CH3CSNH）．通过元素分析。IR、UV、1HNMR、MS表征并用X射线衍射法测得Ⅱ的单晶结构.该簇合物属三斜晶系、PT空间群，晶胞参数：a=0．9203（1），b=1．1296（2），c=1.1425（2）nm；α=116．40°（2），β＝101．92°（2），γ＝92．58°（1）；z＝2，V=1．2162nm3，Dc＝1．698cm3，μ＝21．89cm-1.结构分析表明，Co2FeS构三角锥分子骨架，所有CO均为端基配体，S1为面桥基配体，CH3CSNH为双齿配体，与Co、Fe形成五元环结构．     

Pure Ion Chromatograms Combined with Advanced Machine Learning Methods Improve Accuracy of Discriminant Models in LC–MS-Based Untargeted Metabolomics

Untargeted metabolomics based on liquid chromatography coupled with mass spectrometry (LC–MS) can detect thousands of features in samples and produce highly complex datasets. The accurate extraction of meaningful features and the building of discriminant models are two crucial steps in the data analysis pipeline of untargeted metabolomics. In this study, pure ion chromatograms were extracted from a liquor dataset and left-sided colon cancer (LCC) dataset by K-means-clustering-based Pure Ion Chromatogram extraction method version 2.0 (KPIC2). Then, the nonlinear low-dimensional embedding by uniform manifold approximation and projection (UMAP) showed the separation of samples from different groups in reduced dimensions. The discriminant models were established by extreme gradient boosting (XGBoost) based on the features extracted by KPIC2. Results showed that features extracted by KPIC2 achieved 100% classification accuracy on the test sets of the liquor dataset and the LCC dataset, which demonstrated the rationality of the XGBoost model based on KPIC2 compared with the results of XCMS (92% and 96% for liquor and LCC datasets respectively). Finally, XGBoost can achieve better performance than the linear method and traditional nonlinear modeling methods on these datasets. UMAP and XGBoost are integrated into KPIC2 package to extend its performance in complex situations, which are not only able to effectively process nonlinear dataset but also can greatly improve the accuracy of data analysis in non-target metabolomics.     

In search of covalently bound tetra- and penta-oxygen species: a photoelectron spectroscopic and Ab initio investigation of MO4- and MO5- (M = Li,Na, K,Cs)

Although neutral and ionic O4(0/-/+) species have been observed experimentally and considered for energetic materials, O4(2-) and O5(2-) dianions have not yet been explored. O4(2-) is valent isoelectronic to the well-known ClO3- and SO3(2-) anions, and O5(2-) is valent isoelectronic to ClO4- and SO4(2-). All are stable, common anions in solutions and inorganic salts. In this article, we explore the possibility of making covalently bound O4(2-) and O5(2-) species stabilized in the forms of M+O4(2-) and M+O5(2-) (M = Li, Na, K, Cs) in the gas phase. Laser vaporization experiments using M-containing targets and an O2-seeded carrier gas yielded very intense mass peaks corresponding to MO4- and MO5-. To elucidate the structure and bonding of the newly observed MO4- and MO5- species, we measured their photoelectron spectra and then compared them with ab initio calculations and the spectra of ClO3-, Na+SO3(2-), ClO4-, and Na+SO4(2-). Careful analyses of the experimental and ab initio results showed, however, that the observed species are of the forms, O2-M+O2- and O2-M+O3-. The more interesting M+O4(2-) and M+O5(2-) species were found to be higher-energy isomers, but they are true minima on the potential energy surfaces, which suggests that it might be possible to synthesize bulk materials containing covalently bound tetra- and pentatomic oxygen building blocks.     

Full Dissolution of the Whole Lithium Sulfide Family (Li2S8 to Li2S) in a Safe Eutectic Solvent for Rechargeable Lithium–Sulfur Batteries

The lithium–sulfur battery is an attractive option for next‐generation energy storage owing to its much higher theoretical energy density than state‐of‐the‐art lithium‐ion batteries. However, the massive volume changes of the sulfur cathode and the uncontrollable deposition of Li₂S₂/Li₂S significantly deteriorate cycling life and increase voltage polarization. To address these challenges, we develop an ?‐caprolactam/acetamide based eutectic‐solvent electrolyte, which can dissolve all lithium polysulfides and lithium sulfide (Li₂S₈–Li₂S). With this new electrolyte, high specific capacity (1360 mAh g^?1) and reasonable cycling stability are achieved. Moreover, in contrast to conventional ether electrolyte with a low flash point (ca. 2 °C), such low‐cost eutectic‐solvent‐based electrolyte is difficult to ignite, and thus can dramatically enhance battery safety. This research provides a new approach to improving lithium–sulfur batteries in aspects of both safety and performance.     

Biomimetic stimuli‐responsive nanochannels and their applications

Biomimetic smart nanochannels have been studied extensively to achieve the precise ionic transport compared to biological ion channels. Similar to ion channels in living organisms, biomimetic smart nanochannels can respond to various stimuli, which allows for promising applications in many fields. In this review, we mainly summarize the recent advances in the design of biomimetic stimuli‐responsive nanochannels and their potential applications including biosensors and drug delivery. Finally, an outlook on the challenges and opportunities for biomimetic stimuli‐responsive nanochannels is provided.