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The specific identification and elimination of cancer cells has been a great challenge in the past few decades. In this study, the circular dichroism (CD) of cells was measured by a self-designed special system through the folate-conjugated chiral nano-sensor. A novel method was established to recognize cancer cells from normal cells according to the chirality of cells based on their CD signals. After a period of interaction between the nano-sensor and cells, the sharp weakening of CD signals was induced in cancer cells but normal cells remained unchanged. The biocompatibility of the nano-sensor was evaluated and the result showed that it exhibited significant cytotoxic activity against cancer cells while no obvious damage on normal cells. Notably, the research indicated that the nano-sensor may selectively cause apoptosis in cancer cells, and thus, have the potential to act as an antitumor agent.
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Compostos de Cádmio , Neoplasias/terapia , Pontos Quânticos/química , Sulfetos , Telúrio , Apoptose , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Dicroísmo Circular , Feminino , Ácido Fólico , HumanosRESUMO
This paper evaluates the impacts of migration flows and transportation infrastructure on the spatial transmission of COVID-19 in China. Prefectures with larger bilateral migration flows and shorter travel distances with Hubei, the epicenter of the outbreak, experienced a wider spread of COVID-19. In addition, richer prefectures with higher incomes were better able to contain the virus at the early stages of community transmission. Using a spatial general equilibrium model, we show that around 28% of the infections outside Hubei province can be explained by the rapid development in transportation infrastructure and the liberalization of migration restrictions in the recent decade.
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Inducing apoptosis in cancer cells is considered a potential therapeutic mechanism underlying cancers. Here, chiral folic acid (FA) conjugated Cys-CdTe/CdS quantum dots (QDs) conjugated with a cancer-targeting ligand were fabricated to induce apoptosis in vivo. Ligand-induced chirality mechanism for FA-Cys-CdTe/CdS QDs was discussed, which is verified by density functional theory (DFT) simulation. Interestingly, we found that the circular dichroism (CD) signals of chiral QDs can effectively distinguish breast cancer cells from normal cells, where a sharp decrease in CD signal and absorption intensity can be seen. Notably, chiral FA-Cys-CdTe/CdS QDs showed significant apoptosis-inducing ability after the release of mitochondrial apoptotic factors. Furthermore, in vivo experiments showed that chiral FA-Cys-CdTe/CdS QDs provide an efficient cancer ablation through the apoptosis process with negligible toxicity, demonstrating their great potential utility in targeted anticancer agent for future clinic application.
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Compostos de Cádmio , Neoplasias , Pontos Quânticos , Telúrio , Ácido Fólico , LigantesRESUMO
The garnet Li7La3Zr2O12 (LLZO) has been widely investigated because of its high conductivity, wide electrochemical window, and chemical stability with regards to lithium metal. However, the usual preparation process of LLZO requires high-temperature sintering for a long time and a lot of mother powder to compensate for lithium evaporation. In this study submicron Li6.6La3Zr1.6Nb0.4O12 (LLZNO) powder-which has a stable cubic phase and high sintering activity-was prepared using the conventional solid-state reaction and the attrition milling process, and Li stoichiometric LLZNO ceramics were obtained by sintering this powder-which is difficult to control under high sintering temperatures and when sintered for a long time-at a relatively low temperature or for a short amount of time. The particle-size distribution, phase structure, microstructure, distribution of elements, total ionic conductivity, relative density, and activation energy of the submicron LLZNO powder and the LLZNO ceramics were tested and analyzed using laser diffraction particle-size analyzer (LD), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Electrochemical Impedance Spectroscopy (EIS), and the Archimedean method. The total ionic conductivity of samples sintered at 1200 °C for 30 min was 5.09 × 10-4 S·cm-1, the activation energy was 0.311 eV, and the relative density was 87.3%. When the samples were sintered at 1150 °C for 60 min the total ionic conductivity was 3.49 × 10-4 S·cm-1, the activation energy was 0.316 eV, and the relative density was 90.4%. At the same time, quasi-solid-state batteries were assembled with LiMn2O4 as the positive electrode and submicron LLZNO powder as the solid-state electrolyte. After 50 cycles, the discharge specific capacity was 105.5 mAh/g and the columbic efficiency was above 95%.
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Li-rich layered oxide cathode materials have become one of the most promising cathode materials for high specific energy lithium-ion batteries owning to its high theoretical specific capacity, low cost, high operating voltage and environmental friendliness. Yet they suffer from severe capacity and voltage attenuation during prolong cycling, which blocks their commercial application. To clarify these causes, we synthesize Li1.5Mn0.55Ni0.4Co0.05O2.5 (Li1.2Mn0.44Ni0.32Co0.04O2) with high-nickel-content cathode material by a solid-sate complexation method, and it manifests a lot slower capacity and voltage attenuation during prolong cycling compared to Li1.5Mn0.66Ni0.17Co0.17O2.5 (Li1.2Mn0.54Ni0.13Co0.13O2) and Li1.5Mn0.65Ni0.25Co0.1O2.5 (Li1.2Mn0.52Ni0.2Co0.08O2) cathode materials. The capacity retention at 1 C after 100 cycles reaches to 87.5% and the voltage attenuation after 100 cycles is only 0.460 V. Combining X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM), it indicates that increasing the nickel content not only stabilizes the structure but also alleviates the attenuation of capacity and voltage. Therefore, it provides a new idea for designing of Li-rich layered oxide cathode materials that suppress voltage and capacity attenuation.
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In this paper, the effects of the electrical proper- ties of CuO-doped (Na(0.5)K(0.5))NbO(3) (NKN) ceramics prepared separately using the B-site oxide precursor method (BO method) and conventional mixed-oxide method (MO method) on high-power piezoelectric transformers (PTs) were investigated. The performances of PTs made with these two substrates were compared. Experimental results showed that the output power and temperature stability of PTs could be enhanced because of the lower resonant impedance of the ceramics prepared using the BO method. In addition, the output power of PTs was more affected by the resonant impedance than by the mechanical quality factor (Q(m)) of the ceramics. The PTs fabricated with ceramics prepared using the BO method showed a high efficiency of more than 94% and a maximum output power of 8.98 W (power density: 18.3 W/cm(3)) with temperature increase of 3°C under the optimum load resistance (5 kΩ) and an input voltage of 150 V(pp). This output power of the lead-free disk-type PTs is the best reported so far.
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Cerâmica/química , Cobre/química , Sistemas Microeletromecânicos/instrumentação , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , ChumboRESUMO
Fenton oxidation and coagulation-flocculation-sedimentation (CFS) were both effective in removing many organic constituents of the biotreated coking plant effluent before the final treatment in an activated carbon adsorber. Fenton oxidation broke down most persistent organic pollutants and complex cyanides present in the feed stream and caused the eventual biodegradation of the organic residues in the adsorber. The results of Fenton oxidation followed by adsorption and biodegradation in two biological activated carbon (BAC) adsorbers show that the combined treatment consistently produced a high quality final effluent of <50mg/L in COD(Cr) and <0.5mg/L in total cyanide during the 70-d study without replacing any activated carbon. The BAC function of the adsorber substantially reduced the need for replacing activated carbon making the combined Fenton oxidation-BAC treatment process a cost effective treatment process to recycle the final effluent for many beneficial reuses while meeting the much more stringent discharge limits of the future.
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Biodegradação Ambiental , Carvão Vegetal/química , Coque , Peróxido de Hidrogênio/química , Resíduos Industriais/prevenção & controle , Ferro/química , Adsorção , Cianetos/química , Cianetos/metabolismo , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , ReciclagemRESUMO
Batch experiments were conducted to determine the effects of metal loading and fixing methods on the capacity of granular activated carbon (GAC) for removing cyanide from KCN (pH 11), K(3)Fe(CN)(6) solutions and several SCP effluent samples. KI fixed carbon (Cu/KI-GAC) was the most effective among the GAC samples tested. Adsorption was the primary mechanism of cyanide removal; catalytic oxidation of the adsorbed cyanide on carbon surface contributed a minor amount of the observed removal. Four small adsorbers containing the base GAC and 0-100% of Cu/KI-GAC were employed for treating a Fenton oxidized/precipitated SCP effluent sample. After the start-up period (<3-week) to establish the effective biological activated carbon (BAC) function in the adsorbers, the effluents became stable and met the discharge limits (COD(Cr)<50mg/L and TCN<0.5mg/L); with >30% Cu/KI-GAC in the adsorber, the effluent would meet the discharge limits during the start-up phase.
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Carbono/química , Coque , Cianetos/isolamento & purificação , Resíduos Industriais , AdsorçãoRESUMO
A textile-based ECG system for sleeper is presented. The electrode in the system is supported by a foam pad to ensure good contact as well as comfort to the wearer, and a flexible rubber to ensure that the electrode will electrically connect to the wearer only when pressed. Eight electrodes are multiplexed such that exactly two electrodes are pressed to connect the wearer no matter how the wearer lies. When the wearer lies in different positions, he/she will press different two electrodes, and then the morphology of the output ECG signal will be different accordingly. By this feature, the system can not only detect ECG but also determine the position of the sleeper.