Magnetic Particles with Polymeric Shells Bearing Cholesterol Moieties Sensitize Breast Cancer Cells to Low Doses of Doxorubicin

One of the promising strategies for improvement of cancer treatment is application of a combination therapy. The aim of this study was to investigate the anticancer activity of nanoformulations containing doxorubicin and iron oxide particles covered with polymeric shells bearing cholesterol moieties. It was postulated that due to high affinity to cell membranes, particles comprising poly(cholesteryl acrylate) can sensitize cancer cells to doxorubicin chemotherapy. The performed analyses revealed that the developed systems are effective against the human breast cancer cell lines MCF-7 and MDA-MB-231 even at low doses of the active compound applied (0.5 µM). Additionally, high compatibility and lack of toxicity of the tested materials against human red blood cells, immune (monocytic THP-1) cells, and cardiomyocyte H9C2(2-1) cells was demonstrated. Synergistic effects observed upon administration of doxorubicin with polymer–iron oxide hybrids comprising poly(cholesteryl acrylate) may provide an opportunity to limit toxicity of the drug and to improve its therapeutic efficiency at the same time.     

Transient Capillary Channel Flow Stability

Capillary channel techniques with free liquid surfaces provide very reliable means for liquid management in space. However, capillary channel flow is subject to limitation due to liquid surface instabilities when a critical flow rate is reached. Steady flow rate limitation is a consequence of the choking effect and well understood. Critical steady flow rate computation with a one-dimensional model is related to a numerical singularity which occurs at critical flow. For transient flow the singularity does not occur. Therefore, a new transient stability model is defined. It is based on the steady model, a simplified transient momentum balance, the consideration of the capillary pressure of typical observed surface shapes, and on a simplified dynamic inside the channel. The balance and dynamic are defined by liquid and geometrical properties only and therefore significantly easier to compute than a transient differential equation system. In 2011, experiments were performed in cooperation with NASA on the International Space Station (ISS) to confirm the model for steady flow and validate the new transient model. A new phenomenon is discussed, the flexibility effect, which provides significant additional transient stability for channels of sufficient length. An undesired feedback effect, provoked by the reuse of the liquid in a circular loop of the experimental setup, and which influenced the measurements, is compensated by a semi-empirical model for a feedback ratio.     

Crystal structure of a high-pressure/high-temperature phase of alumina by in situ X-ray diffraction

Alumina (alpha-Al(2)O(3)) has been widely used as a pressure calibrant in static high-pressure experiments and as a window material in dynamic shock-wave experiments; it is also a model material in ceramic science. So understanding its high-pressure stability and physical properties is crucial for interpreting such experimental data, and for testing theoretical calculations. Here we report an in situ X-ray diffraction study of alumina (doped with Cr(3+)) up to 136 GPa and 2,350 K. We observe a phase transformation that occurs above 96 GPa and at high temperatures. Rietveld full-profile refinements show that the high-pressure phase has the Rh(2)O(3) (II) (Pbcn) structure, consistent with theoretical predictions. This phase is structurally related to corundum, but the AlO(6) polyhedra are highly distorted, with the interatomic bond lengths ranging from 1.690 to 1.847 A at 113 GPa. Ruby luminescence spectra from Cr(3+) impurities within the quenched samples under ambient conditions show significant red shifts and broadening, consistent with the different local environments of chromium atoms in the high-pressure structure inferred from diffraction. Our results suggest that the ruby pressure scale needs to be re-examined in the high-pressure phase, and that shock-wave experiments using sapphire windows need to be re-evaluated.     

A new architectural approach for optical burst switching networks based on a common control channel

The new architectural approach to Optical Burst Switching networks presented here features a common control channel and a node locally maintained network model. The Common Control Channel allows for a fast and efficient broadcast of the network Control Packets, which in turn are used by every node to update its Local Network Model. The Local Network Model allows efficient network resource planning as each node is aware of the reservation status intentions for the resources on each node. This paper describes the new C³-OBS architecture, evaluates its comparative performance to regular OBS, assesses the manageable bandwidth for a C³-OBS network and evaluates the common control channel manageable load. The concept of “Well-Informed Node” is defined as a metric of trustfulness on the information managed by the Local Network Model and the scope and application of C³-OBS networks are studied.     

Wetting of Cu Pads by Bi-2.6Ag-xCu Alloys and Phase Equilibria in the Ag-Bi-Cu System

The phase equilibrium in the Ag-Bi-Cu system was experimentally determined at 573 K, 773 K, and 973 K by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) on annealed alloys and liquid/solid couples. The experimental results indicate that the mutual solubility of the components is limited. Based on the present results and literature data, phase equilibria in the Ag-Bi-Cu system were thermodynamically assessed. Wetting of Bi-2.6Ag-xCu alloys on Cu substrates was studied with the sessile drop method in the presence of flux at 573 K and 623 K. It was found that the wetting to non-wetting transition corresponds to the solubility limit of Cu in liquid. Selected solidified solder–substrate couples were cross-sectioned and their interfacial microstructure examined with SEM–EDS. There are no reaction products at the interface, but the copper surface becomes rough because of dissolution by liquid solder.     

Determination of the Influence of c-BN+h-BN Coating Structure on Brittleness

COATINGS applied on cutting tools should becharacterized among other properties by high abrasivewear resistance2,3,5,11-16].Abrasive wearresistance increases with hardness increasing.Manyexperiments have shown linear dependence betweenhardness and abrasive wear for different materials[5,7,9,11,24].This relation however,according to[24]notalways is true.In this work is pointed out,that thisrelation is more complicated and another properties canbe more important then hardness.Linear relation…     

碳质铜页岩-石英混合物的聚(乙二醇)烷基醚浮选(英文)

研究不同聚(乙二醇)烷基醚(CnH2n+1O(C2H4O)m,CnEm))对碳质铜页岩-石英混合物浮选的影响。研究结果表明:所研究的聚(乙二醇)烷基醚(C4E1,C4E2,C4E3,C2E2,C6E2)都可以作为碳质铜页岩的浮选剂。C4E2和C2E2在碳质铜页岩和石英混合物的分离浮选过程中具有最佳的选出率。研究结果可为工业初选阶段分离碳质铜页岩中的有机碳提供参考。     

Fullerene C60 as an inhibitor of high temperature lipid oxidation

Non-isothermal oxidation of a model saturated lipid (stearic acid) in the bulk phase in the presence of fullerene C₆₀ at concentrations of 1–8 mM was monitored by differential scanning calorimetry in order to determine the kinetic parameters that describe the global first order oxidation process. The activation energies, pre-exponential factors, and rate constants calculated by the Ozawa–Flynn–Wall method for the first detectable exothermic effect of oxidation, indicate the antioxidant behavior of C₆₀ over a wide range of temperatures that makes it a non-corrosive agent effectively increasing the oxidative stability of lubricants and biolubricants.     

The lifetime prediction of a rotary screw compressor of a liquid cooler subjected to high pressure and high frequency loads

The estimation of the lifetime of high pressure and high frequency loaded components by testing is very costly and time-consuming. The simulation of fatigue life is an important design step in the fast moving and competitive automotive industry, where the steady rise of engineering components and the demand for lightweight construction concurred with enhanced reliability require an optimized dimensioning process. The paper presents the chosen problems of 3D numerical strength and fatigue simulation of a rotary screw compressor of a liquid cooler. The presented results of the FEM mechanical calculation based on a real components. The fatigue analysis were executed using the criterion of critical plane. Local multi-axial state of stresses and deformation has been calculated based on Hooke’s law with simultaneous consideration of kinematics hardening rule of material according to Jiang’s model.     

Steroid-Functionalized Imidazolium Salts with an Extended Spectrum of Antifungal and Antibacterial Activity

It is established that high rates of morbidity and mortality caused by fungal infections are related to the current limited number of antifungal drugs and the toxicity of these agents. Imidazolium salts as azole derivatives can be successfully used in the treatment of fungal infections in humans. Steroid-functionalized imidazolium salts were synthesized using a new, more efficient method. As a result, 20 salts were obtained with high yields, 12 of which were synthesized and characterized for the first time. They were derivatives of lithocholic acid and 3-oxo-23,24-dinorchol-4-ene-22-al and were fully characterized by ¹H and ¹³C nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and high resolution mass spectrometry (HRMS). Due to the excellent activity against bacteria and Candida albicans, new research was extended to include tests on five species of pathogenic fungi and molds: Aspergillus niger ATCC 16888, Aspergillus fumigatus ATCC 204305, Trichophyton mentagrophytes ATCC 9533, Cryptococcus neoformans ATCC 14116, and Microsporum canis ATCC 11621. The results showed that the new salts are almost universal antifungal agents and have a broad spectrum of activity against other human pathogens. To initially assess the safety of the synthesized salts, hemocompatibility with host cells and cytotoxicity were also examined. No toxicity was observed at the concentration at which the compounds were active against pathogens.