Therapeutic Effects of hiPSC-Derived Glial and Neuronal Progenitor Cells-Conditioned Medium in Experimental Ischemic Stroke in Rats

Transplantation of various types of stem cells as a possible therapy for stroke has been tested for years, and the results are promising. Recent investigations have shown that the administration of the conditioned media obtained after stem cell cultivation can also be effective in the therapy of the central nervous system pathology (hypothesis of their paracrine action). The aim of this study was to evaluate the therapeutic effects of the conditioned medium of hiPSC-derived glial and neuronal progenitor cells in the rat middle cerebral artery occlusion model of the ischemic stroke. Secretory activity of the cultured neuronal and glial progenitor cells was evaluated by proteomic and immunosorbent-based approaches. Therapeutic effects were assessed by overall survival, neurologic deficit and infarct volume dynamics, as well as by the end-point values of the apoptosis- and inflammation-related gene expression levels, the extent of microglia/macrophage infiltration and the numbers of formed blood vessels in the affected area of the brain. As a result, 31% of the protein species discovered in glial progenitor cells-conditioned medium and 45% in neuronal progenitor cells-conditioned medium were cell type specific. The glial progenitor cell-conditioned media showed a higher content of neurotrophins (BDNF, GDNF, CNTF and NGF). We showed that intra-arterial administration of glial progenitor cells-conditioned medium promoted a faster decrease in neurological deficit compared to the control group, reduced microglia/macrophage infiltration, reduced expression of pro-apoptotic gene Bax and pro-inflammatory cytokine gene Tnf, increased expression of anti-inflammatory cytokine genes (Il4, Il10, Il13) and promoted the formation of blood vessels within the damaged area. None of these effects were exerted by the neuronal progenitor cell-conditioned media. The results indicate pronounced cytoprotective, anti-inflammatory and angiogenic properties of soluble factors secreted by glial progenitor cells.     

The Formation of Calcified Nanospherites during Micropetrosis Represents a Unique Mineralization Mechanism in Aged Human Bone

Osteocytes—the central regulators of bone remodeling—are enclosed in a network of microcavities (lacunae) and nanocanals (canaliculi) pervading the mineralized bone. In a hitherto obscure process related to aging and disease, local plugs in the lacuno‐canalicular network disrupt cellular communication and impede bone homeostasis. By utilizing a suite of high‐resolution imaging and physics‐based techniques, it is shown here that the local plugs develop by accumulation and fusion of calcified nanospherites in lacunae and canaliculi (micropetrosis). Two distinctive nanospherites phenotypes are found to originate from different osteocytic elements. A substantial deviation in the spherites' composition in comparison to mineralized bone further suggests a mineralization process unlike regular bone mineralization. Clearly, mineralization of osteocyte lacunae qualifies as a strong marker for degrading bone material quality in skeletal aging. The understanding of micropetrosis may guide future therapeutics toward preserving osteocyte viability to maintain mechanical competence and fracture resistance of bone in elderly individuals.     

Deposition welding of hot forging dies using nanoparticle reinforced weld metal

In the application field of forging, the form-giving tool components are subject to process-related severe environmental conditions, such as high mechanical loads acting simultaneously with high tribological and thermal charges. Due to high machine hour rates as well as increasing environmental requirements in terms of energy consumption, wear protection methods and suitable repair measures for forging tools become more and more important. Laser deposition welding represents an established process for the repair of complex shaped surfaces. A new approach is the addition of nano-sized ceramic particles to improve the mechanical properties. The main idea is to reduce the grain size of the cladded layers by adding nano-sized nuclei. A fine grained microstructure will improve strength as well as ductility and fatigue resistance. Furthermore small hard particles can improve the wear resistance without affecting the friction of the surface. After the cladding process the surface has to be finished usually by turning, milling and grinding operations. Within the presented paper the potential of nanoparticle-reinforced deposition welding with regard to increasing the wear resistance of forging dies will be examined. First, the process of nanoparticle-reinforced deposition welding will be presented. Afterwards it will be shown that yttrium oxide, titanium carbide and tungsten carbide nanoparticles in an AISI H10 matrix material will influence the friction coefficient between forging tool and material as well as the wear properties.     

Transferrin-Decorated Niosomes with Integrated InP/ZnS Quantum Dots and Magnetic Iron Oxide Nanoparticles: Dual Targeting and Imaging of Glioma

The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting. Transmission electron microscopy confirmed the complete co-encapsulation of MIONs and QDs in the niosomes. Flow cytometry analysis demonstrated enhanced cellular uptake of the niosomal formulation by glioma cells. In vitro imaging studies showed that PEGNIO/QDs/MIONs/Tf produces an obvious negative-contrast enhancement effect on glioma cells by magnetic resonance imaging (MRI) and also improved fluorescence intensity under fluorescence microscopy. This novel platform represents the first niosome-based system which combines magnetic nanoparticles and QDs, and has application potential in dual-targeted imaging of glioma.     

Schwarz lemma for driving point impedance functions and its circuit applications

In this paper, a boundary version of the Schwarz lemma is investigated for driving point impedance functions and its circuit applications. It is known that driving point impedance function, Z(s) = 1 + c_p(s − 1)^p + c_{p + 1}(s − 1)^{p + 1} + ..., p > 1, is an analytic function defined on the right half of the s-plane. Two theorems are presented using the modulus of the derivative of driving point impedance function, |Z′(0)|, by assuming the Z(s) function is also analytic at the boundary point s = 0 on the imaginary axis with . In the obtained inequalities, the value of the function at s = 1 and the derivatives with different orders have been used. Finally, the sharpness of the inequalities obtained in the presented theorems is proved. Simple LC circuits are obtained using the obtained driving point impedance functions.     

Ru incorporated Ni-MCM-41 mesoporous catalysts for dry reforming of methane: Effects of Mg addition, feed composition and temperature

Nickel incorporated MCM-41-like mesoporous materials, which were synthesized following a one-pot hydrothermal route, were promoted by Ru and Mg in order to improve their catalytic performances for dry reforming of methane. In this study, Ni-MCM-41 based catalysts (with a Ni/Si molar ratio of 0.2), containing different amounts of Ru (0.5-3.0 wt%) and Mg (1 and 5 wt%) were prepared by using sequential impregnation of Ru and Mg into Ni-MCM-41. Dry reforming of methane was studied in a tubular flow reactor in the temperature range of 500-600 °C with different CH₄/CO₂ ratios in the feed stream. Quite high hydrogen yield values and improved stability of these catalysts indicated the promoting effects of Ru for the Ni-MCM-41 type catalysts. Ru incorporation (1.0% Ru) was shown to improve H₂ yields. Mg impregnation into 1.0Ru@Ni-MCM-41 improved catalytic performance by increasing CH₄ conversion and decreasing the contribution of reverse water gas shift reaction, especially at initial times (first 60 min). Coke formation by decomposition of CH₄ contributed to the hydrogen selectivity, but did not cause significant change in catalytic performance, especially at longer reaction times.     

The effect of recycling number on the mechanical,chemical, thermal,and rheological properties of PBT/PC/ABS ternary blends: With and without glass‐fiber

The recycling possibilities of poly(butylene terephthalate)/polycarbonate/acrylonitrile–butadiene–styrene (PBT/PC/ABS) ternary blend with and without glass‐fiber content were investigated using repeated injection molding process. In this study, PBT/PC/ABS ternary blends were reprocessed at five times and the results were presented after each recycling process. The recycling possibility of PBT/PC/ABS ternary blend was evaluated by measuring the mechanical, chemical, thermal, and rheological properties. Mechanical properties were determined by the tensile strength, yield strength, strain at break, elastic modulus, impact strength, flexural strength, and flexural modulus. Chemical and thermal properties were evaluated by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and scanning electron microscopy. Rheological properties of the ternary blends were studied by melt flow index measurement. From the results, it was found that mechanical properties of recycled composites were better than virgin PBT/PC/ABS ternary blends. POLYM. COMPOS., 35:2074–2084, 2014. © 2014 Society of Plastics Engineers     

Hydrogen diffusivity enhancement in alumina pellets due to impregnated palladium

Single-pellet moment technique was used for the evaluation of effective diffusivities and adsorption equilibrium constants of hydrogen, carbon dioxide, and helium in pure alumina and palladium-impregnated alumina pellets. It was found that hydrogen was strongly adsorbed on palladium of Pd-alumina pellets, and significant enhancement of hydrogen diffusivity was observed due to impregnated palladium at 40°C. On the other hand, for carbon dioxide and helium, effective diffusivities obtained in Pd-alumina pellets were smaller than the corresponding values in pure alumina due to higher tortuosity factor values of Pd-alumina pellets.     

Petrochemicals from ethanol over a W-Si-based nanocomposite bidisperse solid acid catalyst

Very high ethylene selectivity values approaching 100% and very high ethanol conversion values approaching 85% were obtained in dehydration of ethanol over a new W-silicate-based nanocomposite catalyst having both meso and macropores and containing a W/Si atomic ratio of 0.85. Silicotungsticacid was successfully incorporated into the catalyst structure following a one-pot hydrothermal synthesis procedure. This catalyst is highly stable and does not loose activity in polar solvents and it has a sufficiently high surface area for catalytic applications. Calcination temperature of the catalyst was found to have a very significant effect on the catalyst structure and also on its catalytic performance in ethanol dehydration. Maximum selectivity of the second major reaction product diethylether was obtained as 0.7 at 200 °C, with the catalyst which was calcined at 400 °C. Very high ethylene and diethylether yield values obtained in this study at different reaction conditions are highly promising for the production of petrochemicals from ethanol.