Sulfur-Modified Oxygen Vacancies in Iron–Cobalt Oxide Nanosheets: Enabling Extremely High Activity of the Oxygen Evolution Reaction to Achieve the Industrial Water Splitting Benchmark

The oxygen vacancies of defective iron–cobalt oxide (FeCoO_x-Vo) nanosheets are modified by the homogeneously distributed sulfur (S) atoms. S atoms can not only effectively stabilize oxygen vacancies (Vo), but also form the Co−S coordination with Co active site in the Vo, which can modulate the electronic structure of the active site, enabling FeCoO_x-Vo-S to exhibit much superior OER activity. FeCoO_x-Vo-S exhibits a mass activity of 2440.0 A g⁻¹ at 1.5 V vs. RHE in 1.0 m KOH, 25.4 times higher than that of RuO₂. The Tafel slope is as low as 21.0 mV dec⁻¹, indicative of its excellent charge transfer rate. When FeCoO_x-Vo-S (anode catalyst) is paired with the defective CoP₃/Ni₂P (cathode catalyst) for overall water splitting, current densities of as high as 249.0 mA cm⁻² and 406.0 mA cm⁻² at a cell voltage of 2.0 V and 2.3 V, respectively, can be achieved.     

Detection of caffeine and its main metabolites for early diagnosis of Parkinson's disease using micellar electrokinetic capillary chromatography

Caffeine (CA) is a common xanthine alkaloid found in tea leaves, coffee beans, and other natural plants, and is the most widely used psychotropic substance in the world. Accumulating evidence suggests that low plasma levels of CA and its metabolites may serve as reliable diagnostic markers for early Parkinson's disease (PD) patients. In this study, we demonstrated a new MEKC method for determining CA and its three main downstream metabolites, paraxanthine (PX), theobromine (TB), and theophylline (TP), in human plasma. Plasma samples were collected, and analyzed using MEKC, after SPE. The running buffer was composed of 35 mM phosphate, pH of 10.5, and 25 mM SDS. The separation voltage was 15 kV and the detection wavelength was at 210 nm. Under the optimum conditions, four distinct analytes were completely separated and detected in less than 12 min. Method limits of detection were as low as 7.5 ng/mL for CA, 5.0 ng/mL for TB, and 4.0 ng/mL for both PX and TP. The recoveries were between 88.0% and 105.9%. This method was successfully applied to 27 human plasma samples. The results indicate that the plasma concentrations of the four analytes are significantly lower in patients with early PD than in control subjects (p < 0.05). The area under curve was improved to 0.839 when CA and its three main metabolites were included, suggesting that MEKC testing of CA, TP, TB, and PX may serve as a potential method for early diagnosis of PD.     

Metal–Organic Frameworks as Metal Ion Precursors for the Synthesis of Nanocomposites for Lithium‐Ion Batteries

Metal–organic frameworks (MOFs) are promising materials with fascinating properties. Their widespread applications are sometimes hindered by the intrinsic instability of frameworks. However, this instability of MOFs can also be exploited for useful purposes. Herein, we report the use of MOFs as metal ion precursors for constructing functional nanocomposites by utilizing the instability of MOFs. The heterogeneous growth process of nanostructures on substrates involves the release of metal ions, nucleation on substrates, and formation of a covering structure. Specifically, the synthesized CoS with carbon nanotubes as substrates display enhanced performance in a lithium‐ion battery. Such strategy not only presents a new way for exploiting the instability of MOFs but also supplies a prospect for designing versatile functional nanocomposites.     

Fluevirines E and F,two new alkaloids from Flueggea virosa

Abstract

Two new alkaloids, fluevirines E (1) and F (2), along with six known Securinega alkaloids, were isolated from the methanol extract of the twigs and leaves of Flueggea virosa. The structures and absolute configurations of the new compounds were elucidated by means of MS, NMR, and ECD analyses. Compound 1 is a new dimeric indole alkaloid while 2 is a new securinega-type alkaloid. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines and their acetylcholinesterase inhibitory activity were also evaluated.     

Benzophenone glycosides from the pericarps of Aquilaria yunnanensis S. C. Huang

Abstract

Two new benzophenone glycosides, aquilarisides A (1) and B (2), together with six known analogues (3-8) were isolated from the pericarps of Aquilaria yunnanensis S. C. Huang. Their structures were elucidated on the basis of 1D and 2D NMR and mass spectroscopic analyses, and the absolute configuration of compound 1 was determined by experimental and calculated electronic circular dichroism (ECD) spectra. Anti-inflammatory activities of all compounds 1–8 were evaluated for their inhibitory activities against lipopolysaccharide (LPS)-stimulated induced nitric oxide (NO) production in RAW 264.7 cells using the Griess assay. Compound 2 indicated a weak inhibition of NO production.     

Ribbon of DNA Lattice on Gold Nanoparticles for Selective Drug Delivery to Cancer Cells

Herein, we report on the design of a programmable DNA ribbon using long‐chain DNA molecules with a user‐defined repetitive padlock sequence. The DNA ribbon can be further combined with gold nanoparticles (AuNPs) to create a composite nanomaterial that contains an AuNP core and a high‐density DNA crown carrying a cancer‐cell‐targeting DNA aptamer, a fluorescent tag for location tracking, and a cell‐killing drug. This composite material can be efficiently internalized by cancer cells and its cellular location can be tracked by fluorescence imaging. The system offers several attractive characteristics, including simple design, tunable DNA crown, high drug‐loading capacity, selective cell targeting, and pH‐sensitive drug release. These features make such a material a promising therapeutic agent.     

K9和石英玻璃基片上Au膜真空紫外反射特性研究

采用离子束溅射法,分别在经过不同前期清洗方法处理过的K9及石英玻璃光学基片上,选择不同的镀膜参量,镀制了多种厚度的Au膜。对镀制的Au膜在真空紫外波段较宽波长范围内的反射率进行了连续测量。测试结果表明:辅助离子源的使用方式、Au膜厚度对反射镜的反射率有重大影响。基片材料、镀前基片表面清洗工艺等对反射率也有一定影响。采用镀前离子轰击,可显著提高Au膜反射率及膜与基底的粘合力;获得最高反射率时的最佳膜厚与基片材料、镀膜工艺密切相关。对经过离子清洗的石英基片,膜厚在30 nm左右反射率最高;比较而言,石英基片可获得更高的反射率;辅助离子源的使用还显著影响获得最高反射率时对应的最佳膜厚值,且对K9基片的影响更显著。     

对正负一级能量之比测量光栅参量方法的改进

提出利用同一波长的入射光在双面入射时两个能量之比的比值对光栅的参量进行测量,进一步提高准确度。首先从理论上比较正弦面形光栅在单一面入射及双面入射时各种衍射效率对光栅表面粗糙度的敏感程度;然后模拟测量出该正弦面型光栅在双面入射情况下的光栅参量;最后成功反演出体积相位全息光栅的三个参量,其测量结果为0.080μm,1.452μm,20.5μm准确度比单一入射面情况(0.080μm,1.451μm,20.1μm)时要高。同时该法继承了原来方法的无损伤、操作简便、可重复、易推广、成本低等优点。     

毛细管电泳-间接化学发光法检测染发剂中苯二酚异构体和苯酚

根据某些酚类化合物在碱性条件下具有能猝灭鲁米诺-铁氰化钾体系化学发光信号的特性,建立了毛细管电泳-间接化学发光分离检测苯二酚异构体和苯酚的新方法.电泳缓冲溶液选用7.5 mmol/L Na2B4O7-2.5 mmol/L Na2HPO4.在优化的化学发光和电泳条件下,对苯二酚、间苯二酚、邻苯二酚和苯酚在10 min内可直接实现分离,其检出限(S/N=3)分别为2.9×10-8 mol/L、3.7×10-7 mol/L、8.4×10-8 mol/L和4.4×10-6 mol/L;相对标准偏差(RSD)为2.5%～4.8%(n=5).通过对不同染发剂实际样品进行分离分析研究,证明该方法可以用于实际染发剂样品的分析测定,结果令人满意.     

新工科项目“地方(行业)高校化学类专业应对产业变化的升级改造研究与实践”的实施

This "emerging engineering education (3E)" project "Upgrade and Practice of Chemistry-related Majors of Local and/or Specialized University Responding to the Industry Changes" was supported by the Ministry of Education. To aim at the issue of how to upgrade the chemistry-related majors of a local and/or specialized university responding to industry changes, an investigation on local regional economy and industry changes was carried out, the capability requirements of 3E for talents were analyzed, and the training objectives, graduation requirements as well as the new teaching models were also studied for the major to meet the future requirements. The practical experience for 3E construction of chemistry-related majors by selected universities was suggested.