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991.
Jiangchun Chen Dong An Sicong Wang Han Wang Yingyu Wang Qiaonan Zhu Dr. Dandan Yu Mengyao Tang Prof. Lin Guo Prof. Hua Wang 《Angewandte Chemie (International ed. in English)》2023,62(33):e202307122
Potassium-ion batteries (PIBs) are promising for cryogenic energy storage. However, current researches on low-temperature PIBs are limited to half cells utilizing potassium metal as an anode, and realizing rechargeable full cells is challenged by lacking viable anode materials and compatible electrolytes. Herein, a hard carbon (HC)-based low-temperature potassium-ion full cell is successfully fabricated for the first time. Experimental evidence and theoretical analysis revealed that potassium storage behaviors of HC anodes in the matched low-temperature electrolyte involve defect adsorption, interlayer co-intercalation, and nanopore filling. Notably, these unique potassiation processes exhibited low interfacial resistances and small reaction activation energies, enabling an excellent cycling performance of HC with a capacity of 175 mAh g−1 at −40 °C (68 % of its room-temperature capacity). Consequently, the HC-based full cells demonstrated impressive rechargeability and high energy density above 100 Wh kg−1cathode at −40 °C, representing a significant advancement in the development of PIBs. 相似文献
992.
993.
Wanling Liu Yihong Zhang Gen Wei Minxuan Zhang Tong Li Quanyi Liu Zijun Zhou Yan Du Prof. Dr. Hui Wei 《Angewandte Chemie (International ed. in English)》2023,62(33):e202304465
Senescent cells are the critical drivers of atherosclerosis formation and maturation. Mitigating senescent cells holds promise for the treatment of atherosclerosis. In an atherosclerotic plaque microenvironment, senescent cells interact with reactive oxygen species (ROS), promoting the disease development. Here, we hypothesize that a cascade nanozyme with antisenescence and antioxidant activities can serve as an effective therapeutic for atherosclerosis. An integrated cascade nanozyme with superoxide dismutase- and glutathione peroxidase-like activities, named MSe1, is developed in this work. The obtained cascade nanozyme can attenuate human umbilical vein endothelial cell (HUVEC) senescence by protecting DNA from damage. It significantly weakens inflammation in macrophages and HUVECs by eliminating overproduced intracellular ROS. Additionally, the MSe1 nanozyme effectively inhibits foam cell formation in macrophages and HUVECs by decreasing the internalization of oxidized low-density lipoprotein. After intravenous administration, the MSe1 nanozyme significantly inhibits the formation of atherosclerosis in apolipoprotein E-deficient (ApoE−/−) mice by reducing oxidative stress and inflammation and then decreases the infiltration of inflammatory cells and senescent cells in atherosclerotic plaques. This study not only provides a cascade nanozyme but also suggests that the combination of antisenescence and antioxidative stress holds considerable promise for treating atherosclerosis. 相似文献
994.
Self-organized ZnO nanorod with photooxidative cell membrane perforation enables large-scale cell manipulation 总被引:1,自引:0,他引:1
Various devices have been developed for verification and application of cellular functions in recent years. In our previous
study, we found that local oxidation reactions in the cell membrane could produce submicron sizes of reversible membrane perforations
in cells, while more than 80% of treated cells were viable even after perforations; therefore, to date, we have attempted
some applications of this mechanism and analyzed their feasibility. In the present study, we developed a rod-shaped device
in which the function of membrane perforation is added by utilizing a photosensitizer and, using the device, we have attempted
to produce membrane perforations in a large number of cells. Zinc oxide nanorods were synthesized on the basis of the vapor–liquid–solid
mechanism and α-terthienyl (photosensitizer) was adsorbed onto gold at the top of the rods to add a membrane perforation function.
We studied the effect of the oxidation catalytic ability of the rods on rat PC12 cells after pressing and making the rods’
growth side come into contact with the base plate pressed onto the cells in a culture plate followed by photoexcitation of
the photosensitizer for a certain period of time. It was revealed that water-soluble fluorescent marker molecules added extracellularly
were taken up by the cells when the rods were applied at a pressure of 70 g/cm2, with a light intensity of 0.82 W/cm2, and with light irradiation for 30 s, as found in the case of the conventional photochemical cell membrane perforation method
targeted at a single cell. These results suggest that cell membrane perforation can be successfully achieved in a large number
of cells at a time.
Figure Large-scale cell membrane perforation process using self-organized nanorods 相似文献
995.
The good,the bad,and the tiny: a review of microflow cytometry 总被引:2,自引:1,他引:1
Ateya DA Erickson JS Howell PB Hilliard LR Golden JP Ligler FS 《Analytical and bioanalytical chemistry》2008,391(5):1485-1498
Recent developments in microflow cytometry have concentrated on advancing technology in four main areas: (1) focusing the particles to be analyzed in the microfluidic channel, (2) miniaturization of the fluid-handling components, (3) miniaturization of the optics, and (4) integration and applications development. Strategies for focusing particles in a narrow path as they pass through the detection region include the use of focusing fluids, nozzles, and dielectrophoresis. Strategies for optics range from the use of microscope objectives to polymer waveguides or optical fibers embedded on-chip. While most investigators use off-chip fluidic control, there are a few examples of integrated valves and pumps. To date, demonstrations of applications are primarily used to establish that the microflow systems provide data of the same quality as laboratory systems, but new capabilities-such as automated sample staining-are beginning to emerge. Each of these four areas is discussed in detail in terms of the progress of development, the continuing limitations, and potential future directions for microflow cytometers. 相似文献
996.
Sharma N Sharma UK Malik S Bhushan S Kumar V Verma SC Sharma N Sharma M Sinha AK 《Journal of separation science》2008,31(4):629-635
Shikonin and its derivatives are important red colored naphthoquinone pigments found in a large number of Arnebia species, including A. euchroma, that are responsible for the various pharmacological activities exhibited by the plant. The precise separation of each naphthoquinone is essential for total quality evaluation and bioactivity analysis of herbal formulations of A. euchroma. Furthermore, the overexploitation of this useful plant has resulted in species becoming endangered. With this in mind, a simple and rapid preparative scale HPLC method with single compound recovery for the isolation and purification of two shikonin derivatives (i. e. acetylshikonin, beta-acetoxyisovalerylshikonin) from cell suspension cultures of A. euchroma is presented. The compounds were separated on a C(18) column within 10 min using acetonitrile/methanol (95:5) as mobile phase in isocratic mode. The isolated compounds were found to be more than 98% pure. The LOD for acetylshikonin and beta-acetoxyisovalerylshikonin was estimated at 0.063 and 0.146 mug/mL, respectively, while the LOQ was found to be 0.209 and 0.487 mug/mL, respectively. The recoveries accomplished for both the shikonin derivatives were in the range of 94.7-96.8%. The repeatability, expressed as %RSD, of acetylshikonin and beta-acetoxyisovalerylshikonin was found to be 1.74 and 1.27, respectively. 相似文献
997.
Boettcher M Jaeger M Kirschbaum M Mueller T Schnelle T Duschl C 《Analytical and bioanalytical chemistry》2008,390(3):857-863
We present a simple lab-on-chip device for handling small samples of delicate cells, e.g. stem cells. It uses a combination
of sedimentation and dielectrophoresis. The transport of cells is driven by gravitation. Dielectrophoresis uses radio-frequency
electric fields for generating particle-selective forces dependent on size and polarisability. Electrodes along the channels
hold particles and/or cells in a defined position and deflect them towards different outlets. The absence of external pumping
and the integration of injection and sampling ports allow the processing of tiny sample volumes. Various functions are demonstrated,
such as contact-free cell trapping and cell/particle sorting. Pairs of human cells and antibody-coated beads, as they are
formed for T cell activation, are separated from unbound beads. The cells experience only low stress levels compared with
the stress levels in dielectrophoresis systems, where transport depends on external pumping. Our device is a versatile yet
simple tool that finds applications in cellular biotechnology, in particular when an economic solution is required.
Figure A simple gravitation-driven lab-on-chip device for the separation of mixed populations of microparticles or cells by negative
dielectrophoresis. 相似文献
998.
Michaela Tesařová Tereza Boušková Pavel Cejnar Jiří Šantrůček Lenka Peterková Zdeněk Fík Petra Sázelová Václav Kašička Radovan Hynek 《Journal of separation science》2023,46(22):2300543
Vestibular schwannoma is the most common benign neoplasm of the cerebellopontine angle. Its first symptoms include hearing loss, tinnitus, and vestibular symptoms, followed by cerebellar and brainstem symptoms, along with palsy of the adjacent cranial nerves. However, the clinical picture has unpredictable dynamics and currently, there are no reliable predictors of tumor behavior. Hence, it is desirable to have a fast routine method for analysis of vestibular schwannoma tissues at the molecular level. The major objective of this study was to verify whether a technique using in-sample specific protein digestion with trypsin would have the potential to provide a proteomic characterization of these pathological tissues. The achieved results showed that the use of this approach with subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of released peptides allowed a fast identification of a considerable number of proteins in two differential parts of vestibular schwannoma tissue as well as in tissues of control healthy samples. Furthermore, mathematical analysis of MS data was able to discriminate between pathological vestibular schwannoma tissues and healthy tissues. Thus, in-sample protein digestion combined with LC-MS/MS separation and identification of released specific peptides followed by mathematical analysis appears to have the potential for routine characterization of vestibular schwannomas at the molecular level. Data are available via ProteomeXchange with identifier PXD045261. 相似文献
999.
为精准防控大气降尘污染,提供其重金属检测方法。重点考察了样品前处理中混合酸体系选择和最佳酸用量比对实验。在最优条件下建立了混合酸(硝酸、氢氟酸、盐酸和高氯酸)湿法消解大气降尘样品和电感耦合等离子体质谱仪进行7种重金属(铊、铅、镉、铬、铜、锌和镍)含量测试的实验方法。实验结果显示7种重金属在一定的浓度范围内线性关系好,线性系数均大于0.999,7种重金属方法检出限为0.02 mg/kg~2.0 mg/kg,实际样品6次测定相对标准偏差为1.1 %~5.7 %,加标回收回收率为87.7 %~108.9 %。该方法经济环保、准确快捷,可作为大气沉降重金属检测参考方法。 相似文献
1000.
《Arabian Journal of Chemistry》2023,16(1):104416
Carica papaya leaf has a potentially well-known therapeutic effect in accelerating human blood platelet counts against dengue fever and dengue haemorrhagic fever. However, consuming the extract was considered troublesome due to its bitter taste. The fresh papaya leaves were extracted into two types of preparation: a) Fresh Papaya Leaves Extract (FPL) and b) Papaya Leaves with Saponin Reduction Extract (PLSR). This was followed by the determination of the best edible O/W emulsion formulation of both different extracts with virgin coconut oil (VCO) and whey protein (WP) as surfactant. Through Ternary Phase Diagram (TPD), the optimum ratio (w/w) of FPL/PLSR: VCO: WP were 63: 16: 21 and 65: 16: 19 respectively. Both formulas were examined for their physicochemical properties including pH, creaming index (CI), contact angle and droplet size measurement. The human bronchial epithelium cell (BEAS-2B) was treated using both emulsions for 72 hrs of cell growth response (EC50). The result shows that both FPL and PLSR formulations were slightly acidic and exhibited stable emulsion with no creaming formation (CI) up to 24 hrs of storage (25 ℃). Next, FPL emulsion shows 3 times higher wettability and 4 times bigger nanoparticle size than PLSR. These properties can affect the emulsion absorptivity in the targeted cell microenvironment. Remarkably, the BEAS-2B cell viability (%) for each emulsion was relatively elevated within 24 hrs and increased to more than 100 % at 48 and 72 hrs of exposure. This might hugely represent its potential in repairing damaged blood vessels due to dengue haemorrhagic fever. Besides, the EC50 value also indicated low levels of concentration needed to exponentially increase cell growth and safe for dengue fever treatment. For that reason, the recommended effective dosage by the Ministry of Health (Malaysia) (MOH) for both FPL and PLSR emulsions is two tablespoons twice a day for three consecutive days of treatment (equally to the effective dosage of 102 g extract). 相似文献