17 research outputs found
The selection of a surfactant for freshwater microalgae harvesting and separation by the foam separation method
Abstract(#br)Collecting microalgae from water with less energy and cost is significant to gain economic profit from microalgae harvesting and processing. Foam separation has certain advantages including low energy consumption, simple operation and easy maintenance of the equipment. Natural surfactants, compared to traditional surfactants, were used to harvest and separate the freshwater microalgae Desmodesmus brasiliensis by foam separation. Results showed a recovery percentage of 93.6% and an enrichment ratio of 23.1 with the natural surfactant cocamidopropyl betaine (CAPB), suggesting that this low-cost surfactant can be applied to microalgae biomass recovery on a commercial scale using foam separation with no negative effect on the content of microalgae chlorophyll, carotenoid or..
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STING activation disrupts tumor vasculature to overcome the EPR limitation and increase drug deposition
The low success rate of cancer nanomedicines has raised debate on the role of the enhanced permeability and retention (EPR) effect on tumor deposition of nanotherapeutics. Here, we report a bifunctional nanoscale coordination polymer (NCP), oxaliplatin (OX)/2′,3′-cyclic guanosine monophosphate–adenosine monophosphate (GA), to overcome the EPR limitation through stimulator of interferon genes (STING) activation and enhance chemotherapeutic and STING agonist delivery for tumor eradication. OX/GA encapsulates GA and OX in the NCP to protect GA from enzymatic degradation and improve GA and OX pharmacokinetics. STING activation by OX/GA disrupts tumor vasculatures and increases intratumoral deposition of OX by 4.9-fold over monotherapy OX-NCP. OX/GA demonstrates exceptional antitumor effects with >95% tumor growth inhibition and high cure rates in subcutaneous, orthotopic, spontaneous, and metastatic tumor models. OX/GA induces immunogenic cell death of tumor cells and STING activation of innate immune cells to enhance antigen presentation. NCPs provide an excellent nanoplatform to overcome the EPR limitation for effective cancer therapy
Urokinase in the treatment of tuberculous pleurisy: a systematic review and meta-analysis
Abstract Objective To evaluate the efficacy of urokinase (UK) treatment for tuberculous pleural effusion (TPE). Methods We searched Chinese biomedical literature database, WanFang data, CNKI, PubMed, EMbase, Web of Science and The Cochrane Library for the randomized controlled trials (RCTs) of urokinase treatment for tuberculous pleurisy from January 2000 to February 2023. Pleural tuberculosis, urokinase and randomized controlled trial were used as keywords. The eligible studies were meta-analyzed by using Revman 5.4.1: risk of bias was assessed, mean difference (MD) and 95% CI were used for continuous variables, pooled studies were conducted using random-effects or fixed-effects models, forest plots were drawn to analyze efficacy, and funnel plots were drawn to discuss publication bias. Results Twenty-nine RCTs were included. The meta-analyzed results showed that, on the basis of routine anti-tuberculosis, comparison between the treatment group treated with urokinase and the control group treated with antituberculosis alone, the time of pleural effusion absorption [MD-5.82, 95%CI (− 7.77, − 3.87); P<0.00001] and the residual pleural thickness [MD-1.31, 95%CI (− 1.70, − 0.91); P<0.00001], pleural effusion drainage volume [MD 822.81, 95%CI (666.46,977.96); P<0.00001], FVC%pred [MD 7.95, 95%CI (4.51,11.40); P<0.00001], FEV1%pred [MD 12.67, 95%CI (10.09,15.24); P<0.00001] were significantly different. Conclusion The clinical effect of urokinase is better than that of antituberculous therapy alone: it can increase total pleural effusion, decrease residual pleural thickness, improve the pulmonary function, and shorten the time of pleural effusion absorption
Design of the Threshold-Controllable Memristor Emulator Based on NDR Characteristics
Due to the high manufacturing cost of memristors, an equivalent emulator has been employed as one of the mainstream approaches of memristor research. A threshold-type memristor emulator based on negative differential resistance (NDR) characteristics is proposed, with the core part being the R-HBT network composed of transistors. The advantage of the NDR-based memristor emulator is the controllable threshold, where the state of the memristor can be changed by setting the control voltage, which makes the memristor circuit design more flexible. The operation frequency of the memristor emulator is about 250 kHz. The experimental results prove the feasibility and correctness of the threshold-controllable memristor emulator circuit
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Mechanoregulatory Cholesterol Oxidase-Functionalized Nanoscale Metal–Organic Framework Stimulates Pyroptosis and Reinvigorates T Cells
Cancer cells alter mechanical tension in their cell membranes. New interventions to regulate cell membrane tension present a potential strategy for cancer therapy. Herein, the increase of cell membrane tension by cholesterol oxidase (COD) via cholesterol depletion in vitro and the design of a COD-functionalized nanoscale metal–organic framework, Hf-TBP/COD, for cholesterol depletion and mechanoregulation of tumors in vivo, are reported. COD is found to deplete cholesterol and disrupt the mechanical properties of lipid bilayers, leading to decreased cell proliferation, migration, and tolerance to oxidative stress. Hf-TBP/COD increases mechanical tension of plasma membranes and osmotic fragility of cancer cells, which induces influx of calcium ions, inhibits cell migration, increases rupturing propensity for effective caspase-1 mediated pyroptosis, and decreases tolerance to oxidative stress. In the tumor microenvironment, Hf-TBP/COD downregulates multiple immunosuppressive checkpoints to reinvigorate T cells and enhance T cell infiltration. Compared to Hf-TBP, Hf-TBP/COD improves anti-tumor immune response and tumor growth inhibition from 54.3% and 79.8% to 91.7% and 95% in a subcutaneous triple-negative breast cancer model and a colon cancer model, respectively
A Multi-Level DDoS Mitigation Framework for the Industrial Internet of Things
The Industrial Internet of Things is growing fast. But the rapid growth of IIoT devices raises a number of security concerns, because the IIoT device is weak in defending against malware, and the method of managing a large number of IIoT devices is awkward and inconvenient. This article proposes a multi-level DDoS mitigation framework (MLDMF) to defend against DDoS attacks for IIoT, which includes the edge computing level, fog computing level, and cloud computing level. Software defined networking is used to manage a large number of IIoT devices and to mitigate DDoS attacks in IIoT. Experimental results show the effectiveness of the proposed framework
Effect of CaO/Na2SiO3 ratio on mechanical properties, microstructures and environmental leaching characteristics of neutralization slag based geopolymers
Neutralization slag (NS) of copper smelting is a waste residue mainly composed of calcium sulfate, which is produced during the process of metal smelting. The large accumulation and storage of NS poses a significant threat to the environment. Therefore, it is imperative to explore a new economically and environmentally friendly approach for recycling NS. This study proposes a method for preparing a new eco-friendly geopolymer material by utilizing NS. A geopolymer with satisfactory mechanical properties was created by employing a hybrid solid activator consisting of CaO-Na2SiO3. The effects of hybrid solid alkali activators calcium oxide (CaO)/sodium silicate (Na2SiO3) ratio on the hydration properties of the NS-based geopolymer were studied, and its curing mechanism was discussed. The results show that, when the hybrid solid activator CaO/Na2SiO3 ratio was 3:1, the maximum 28 d compressive strength of the geopolymer reached 27.8 MPa. The solid activator at a suitable ratio can accelerate the hydration reaction, form higher amounts of C-A-S-H gel and ettringite, reduce the proportion of harmful macropores in the geopolymer, and improve the microstructure of the geopolymer. Toxicity characteristic leaching procedure (TCLP) test confirmed that the NS-based geopolymer had a solidification effect on heavy metals. The leaching concentration of elemental Pb from the neutralised slag feedstock was 7.241 mg/L, while the lowest concentration was 0.286 mg/L in the NS based geopolymer. As a green cementitious material, the NS-based geopolymer is expected to be applied in engineering practice
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Nanoscale Metal–Organic Framework with an X-ray Triggerable Prodrug for Synergistic Radiotherapy and Chemotherapy
As heavy-metal-based nanoscale metal–organic frameworks (nMOFs) are excellent radiosensitizers for radiotherapy via enhanced energy deposition and reactive oxygen species (ROS) generation, we hypothesize that nMOFs with covalently conjugated and X-ray triggerable prodrugs can harness the ROS for on-demand release of chemotherapeutics for chemoradiotherapy. Herein, we report the design of a novel nMOF, Hf-TP-SN, with an X-ray-triggerable 7-ethyl-10-hydroxycamptothecin (SN38) prodrug for synergistic radiotherapy and chemotherapy. Upon X-ray irradiation, electron-dense Hf12 secondary building units serve as radiosensitizers to enhance hydroxyl radical generation for the triggered release of SN38 via hydroxylation of the 3,5-dimethoxylbenzyl carbonate followed by 1,4-elimination, leading to 5-fold higher release of SN38 from Hf-TP-SN than its molecular counterpart. As a result, Hf-TP-SN plus radiation induces significant cytotoxicity to cancer cells and efficiently inhibits tumor growth in colon and breast cancer mouse models
Mechanistic Understanding of Size-Dependent Oxygen Reduction Activity and Selectivity over Pt/CNT Nanocatalysts
Identifying the underlying nature of the structure sensitivity of oxygen reduction reaction (ORR) over carbon supported Pt catalysts is an important but challenging issue in electrochemical system. In this work, we combine experiments, density functional theory calculations with model calculations to clarify the size-dependent ORR activity and selectivity over differently sized Pt/CNT catalysts. HAADF-STEM, HRTEM and XPS measurements show that the Pt nanoparticles supported on CNT possess a well-defined truncated octahedron shape in most cases and similar electronic properties. The observed size-insensitive TOFactive site based on the number of Pt(111) atoms suggests the Pt(111) surface as the dominant active site. Moreover, the Pt(111) surface is also suggested as the dominant active sites for the formation of H2O2, and the catalyst with the higher Pt binding energy facilitates the oxygen reduction to H2O. The insights revealed here could shed new light on the design and optimization of Pt-based ORR catalysts