A Facile Asymmetric Approach to the Multicyclic Core Structure of Mangicol A

Chiral propargylic ether‐based triene–ynes are synthesized with high enantiomeric purity by employing an asymmetric enyne addition to aldehydes catalyzed by 1,1′‐bi‐2‐naphthol in combination with ZnEt₂, Ti(OiPr)₄ and dicyclohexylamine at room temperature. These substrates are found to undergo a one‐pot domino Pauson–Khand and Diels–Alder cycloaddition catalyzed by [RhCl(CO)₂]₂ under CO to generate a series of multicyclic products with high chemoselectivity and stereoselectivity. These products contain the multicyclic core structure of mangicol A which could facilitate the synthesis and study of this class of natural products.     

Two‐Component Supramolecular Gels Derived from Amphiphilic Shape‐Persistent Cyclo[6]aramides for Specific Recognition of Native Arginine

A unique supramolecular two‐component gelation system was constructed from amphiphilic shape‐persistent cyclo[6]aramides and diethylammonium chloride (or triethylammonium chloride). This system has the ability to discriminate native arginine from 19 other amino acids in a specific fashion. Cyclo[6]aramides show preferential binding for the guanidinium residue over ammonium groups. This specificity was confirmed by both experimental results and theoretical simulations. These results demonstrated a new modular displacement strategy, exploring the use of species‐binding hydrogen‐bonded macrocyclic foldamers for the construction of two‐component gelation systems for selective recognition of native amino acids by competitive host–guest interactions. This strategy may be amenable to developing a variety of functional two‐component gelators for specific recognition of various targeted organic molecular species.     

Adsorption separation performance of H2/CH4 on ETS-4 by concentration pulse chromatography

To exploit an effective adsorbent to separate hydrogen and methane, microporous titanium silicate molecular sieve NaETS-4 was synthesized and modified by strontium. The adsorption characteristics and diffusion behaviors of the prepared titanosilicate molecular sieve were studied by concentration pulse chromatography. And the effects of ion-exchange and dehydration temperature on adsorbent structure and gas diffusion were also discussed. The results showed that the thermal stability and Henry＇s Law constants were enhanced and micropore diffusivity decreased after exchanging Na＋ with Sr2＋. With the increase of dehydration temperature, Henry＇s Law constant and micropore diffusivity of CI-I4 decreased in both NaETS-4 and SrETS-4. While for 1-12 in SrETS-4, the increase of Henry＇s Law constant and the decrease of diffusion rate can be attributed to the shrinks of pore diameter resulting from the relocation of Sr2＋. Correspondingly, the kinetic selectivity of H2/CH4 reached 8.91 indicating its potentiality in separating H2 and CH4.     

分子光谱自动检索算法、策略与应用进展

近些年,基于分子光谱(紫外、红外、近红外、拉曼和荧光等)分析技术建立了诸多复杂混合物质的光谱数据库(例如土壤、饲料、物证检材、药物和油品等),这些分子光谱库在现代工农业生产中日益发挥着重要的作用,其中光谱检索方法是充分利用这些光谱数据库的关键手段之一。本文系统综述了用于分子光谱自动检索的算法、策略和应用进展,并提出了需要注意和进一步研究的科学和技术问题。     

A Layered Cationic Aluminum Oxyhydroxide as a Highly Efficient and Selective Trap for Heavy Metal Oxyanions

Cationic framework materials, especially pure inorganic cationic frameworks that can efficiently and selectively capture harmful heavy metal oxyanions from aqueous solution are highly desired yet scarcely reported. Herein, we report the discovery of a 2D cationic aluminum oxyhydroxide, JU-111, which sets a new benchmark for heavy metal oxyanion sorbents, especially for Cr^VI. Its structure was solved based on 3D electron diffraction tomography data. JU-111 shows fast sorption kinetics (ca. 20 min), high capture capacity (105.4 mg g⁻¹), and broad working pH range (3–10) toward Cr^VI oxyanions. Unlike layered double hydroxides (LDHs), which are poorly selective in the presence of CO₃²⁻, JU-111 retains excellent selectivity for Cr^VI even under a large excess of CO₃²⁻. These superior features coupled with the ultra-low cost and environmentally benign nature make JU-111 a promising candidate for toxic metal oxyanion remediation as well as other potential applications.     

Quick stabilization of capillary for rapid determination of potassium ions in the blood of epilepsy patients by capillary electrophoresis without sample pretreatment

Mutations in the potassium channel genes may be linked to the development of epilepsy and affect the blood potassium levels. Therefore, accurate determination of potassium in the blood will be critical to diagnose the cause of epilepsy. CE is a competent technique for the fast detection of multiple ions, but complicated matrices of a blood sample may cause significant variation of migration times and the peak shape. In this work, a procedure for rapid stabilization of the capillary inner surface through preflushing of a blood sample was employed. The process takes only 40 min for a capillary and then it can be used for more than 2 weeks. No pretreatment of the blood sample or other surface modification of the capillary is needed for the analysis. The RSDs of the migration time and peak area were reduced to 1.5 and 5.1% from 12.6 and 14.5%, respectively. The proposed method has been successfully applied to the determination of the potassium contents in the blood sample of patients with epilepsy at different stages. The recoveries of potassium ions in these blood samples are in a range from 86.5 to 104.5%.     

An Activatable Polymeric Reporter for Near-Infrared Fluorescent and Photoacoustic Imaging of Invasive Cancer

Discriminative detection of invasive and noninvasive breast cancers is crucial for their effective treatment and prognosis. However, activatable probes able to do so in vivo are rare. Herein, we report an activatable polymeric reporter (P-Dex) that specifically turns on near-infrared (NIR) fluorescent and photoacoustic (PA) signals in response to the urokinase-type plasminogen activator (uPA) overexpressed in invasive breast cancer. P-Dex has a renal-clearable dextran backbone that is linked with a NIR dye caged with an uPA-cleavable peptide substrate. Such a molecular design allows P-Dex to passively target tumors, activate NIR fluorescence and PA signals to effectively distinguish invasive MDA-MB-231 breast cancer from noninvasive MCF-7 breast cancer, and ultimately undergo renal clearance to minimize the toxicity potential. Thus, this polymeric reporter holds great promise for the early detection of malignant breast cancer.     

基于“1+2”模式的结构化学课程在线教学实践

Since the outbreak of novel coronavirus pneumonia (NCP) at the beginning of this year, Chinese government acted immediately and made some regulations to control the epidemic NCP and promote the recovery of society and industry including education. Chinese universities stayed on the online courses without suspension on teaching and learning. Herein, we report online teaching of structural chemistry course based on the teaching mode of online live broadcast platform, online course resources and management platforms ("1 + 2" mode). This may promote online teaching, and take advantage of online live broadcast and massive open online courses, which achieves good teaching and learning experiences on structural chemistry course.     

活性炭/有机质复合相变材料的热-电性能

用活性炭(AC)作为支撑材料,石蜡(PW)、十六酸(PA)和硬脂酸(SA)作为相变主材,通过熔融共混法制备AC/PW、AC/PA和AC/SA复合相变材料,并考察了其热-电性能。结果表明,添加活性炭时有机质均不会泄漏;复合材料充-放热过程中温度场分布都比较均匀,热循环会使材料导热性能略有下降;此外,三种复合材料的电阻率均随压力增加而减小。     

Responsive Exosome Nano‐bioconjugates for Synergistic Cancer Therapy

Exosomes hold great potential in therapeutic development. However, native exosomes usually induce insufficient effects in vivo and simply act as drug delivery vehicles. Herein, we synthesize responsive exosome nano‐bioconjugates for cancer therapy. Azide‐modified exosomes derived from M1 macrophages are conjugated with dibenzocyclooctyne‐modified antibodies of CD47 and SIRPα (aCD47 and aSIRPα) through pH‐sensitive linkers. After systemic administration, the nano‐bioconjugates can actively target tumors through the specific recognition between aCD47 and CD47 on the tumor cell surface. In the acidic tumor microenvironment, the benzoic‐imine bonds of the nano‐bioconjugates are cleaved to release aSIRPα and aCD47 that can, respectively, block SIRPα on macrophages and CD47, leading to abolished “don't eat me” signaling and improved phagocytosis of macrophages. Meanwhile, the native M1 exosomes effectively reprogram the macrophages from pro‐tumoral M2 to anti‐tumoral M1.