127 research outputs found
Electrostatic complexation of polyelectrolyte and magnetic nanoparticles: from wild clustering to controllable magnetic wires
Emerging therapies for breast cancer
Abstract HER2 and CDK4/6 are undoubted two most important biological targets for breast cancer. Anti-HER2 treatments enhance objective response and progression-free survival/disease-free survival as well as overall survival. Three CDK4/6 inhibitors consistently improve objective response and progression-free survival; however, overall survival data are waited. Optimization of chemotherapy and endocrine strategies remains an unmet need. Check point inhibitor-based immunotherapy combined with chemotherapy is a promising field, especially for triple-negative breast cancer
Electrostatic complexation of polyelectrolyte and magnetic nanoparticles: from wild clustering to controllable magnetic wires
We present the electrostatic complexation between polyelectrolytes and charged nanoparticles. The nanoparticles in solution are γ-Fe(2)O(3) (maghemite) spheres with 8.3 nm diameter and anionic surface charges. The complexation was monitored using three different formulation pathways such as direct mixing, dilution, and dialysis. In the first process, the hybrids were obtained by mixing stock solutions of polymers and nanoparticles. A ‘destabilization state’ with sharp and intense maximum aggregation was found at charges stoichiometry (isoelectric point). While on the two sides of the isoelectric point, ‘long-lived stable clusters state’ (arrested states) were observed. Dilution and dialysis processes were based on controlled desalting kinetics according to methods developed in molecular biology. Under an external magnetic field (B = 0.3 T), from dialysis at isoelectric point and at arrested states, cationic polyelectrolytes can ‘paste’ these magnetic nanoparticles (NPs) together to yield irregular aggregates (size of 100 μm) and regular rod-like aggregates, respectively. These straight magnetic wires were fabricated with diameters around 200 nm and lengths comprised between 1 μm and 0.5 mm. The wires can have either positive or negative charges on their surface. After analyzing their orientational behavior under an external rotating field, we also showed that the wires made from different polyelectrolytes have the same magnetic property. The recipe used a wide range of polyelectrolytes thereby enhancing the versatility and applied potentialities of the method. This simple and general approach presents significant perspective for the fabrication of hybrid functional materials
Probing carbon-based composite coatings toward high vacuum lubrication application
For challenges in minimizing friction and wear of spatial mechanical systems, synergetic lubrication coatings were prepared by spinning liquid lubricants and hybrid greases on the diamond-like carbon (DLC) films, and were evaluated whether they could achieve a long-term safe and reliable operation under high vacuum. Under high vacuum conditions, liquid lubricants significantly reduce the friction and wear of DLC films. Hybrid greases not only show excellent lubrication performance, but also greatly enhance the tribological behavior of DLC films, especially the grease with optimal proportion. Such excellent tribological performance of DLC-based composite coatings at low applied loads depends on the synergy of DLC and fluid film, in reverse the tribo-chemical reaction film under harsh working conditions
Solvent-free carbon sphere nanofluids towards intelligent lubrication regulation
Abstract By simply switching the electrical circuit installed on steel/steel contact, the tribological behaviors of nanofluids (NFs) can be regulated in real time, thereby achieving the desired performance of friction reduction and wear resistance. Herein, solvent-free carbon spherical nanofluids (C-NFs) were successfully prepared for intelligent lubrication regulation. C-NFs with excellent lubrication performance can immediately reduce the coefficient of friction (COF) despite applying a weak electric potential (1.5 V). Moreover, polyethylene glycol 400 (PEG400) containing 5.0 wt% C-NFs remained responsive to electrical stimulation under the intermittent voltage application with an average coefficient of friction (ACOF) reduction of 20.8% over PEG400. Such intelligent lubrication regulation of C-NFs under an external electric field (EEF) mainly depends on the orderly arranged double-electric adsorption film of ion canopy-adsorbed carbon spheres (CSs). The intermittent electrical application can continuously reinforce the adsorption film and its durability for real-time controlling the sliding interfaces. Electrical-stimulation-responsive intelligent lubricants provide a new technical support for realizing intelligent stepless control of devices
Effect of Hindered Phenol Crystallization on Properties of Organic Hybrid Damping Materials
Organic hybrid damping materials have achieved sustainable development in recent years for superior damping properties due to the hydrogen bonding of hindered phenol. However, the aggregation and crystallization of hindered phenol in the matrix can lead to a sharp decline in material properties. Thus, a series of hindered phenol hybrid carboxylated nitrile rubber (XNBR) composites with different types and contents of hindered phenol were prepared by melt blending to study the effects of different hindered phenol on the properties of organic hybrid damping materials. A dynamic mechanical analyzer (DMA) and scanning electron microscope (SEM) were used to study the dynamic mechanical properties and cross-section morphology of composites. X-ray diffraction (XRD) was used to study the crystallization of hindered phenol. The results show that the properties of organic hybrid damping materials were affected by the structure of hindered phenol, and that hindered phenol molecules with a linear structure had better performances. The greater the number of hydrogen bonds between hindered phenol and the XNBR matrix, the more difficult it was for the hindered phenol to crystallize
Probing carbon-based composite coatings toward high vacuum lubrication application
Probing carbon-based composite coatings toward high vacuum lubrication applicatio
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