Inflammation in embryology: A review of neuroinflammation in spina bifida

The occurrence of neuroinflammation after the failure of neural tube closure, resulting in spina bifida aperta, is well established but whether or not neuroinflammation contributes to damage to the neuroepithelium prior to and during closure is not known. Neuroinflammation may occur at different time periods after perturbation to the developing spinal cord. Evidence suggests that early neuroinflammation is detrimental, whereas the later chronic phase of neuroinflammation may have useful roles. The role of neuroinflammation in neural tube defects is complex. It is important to make the distinction of whether neuroinflammation is important for neuroprotection or detrimental to the neural tissue. This may directly be influenced by the location, magnitude and duration of the insult, as well as the expression of neurotrophic or neurotoxic molecules. The current understanding remains that the chronic damage to the developing spinal cord is likely due to the chemical and mechanical damage of the exposed neural tissue owing to the aggressive intrauterine environment, described as the “two-hit mechanism”. Astrogliosis in the exposed spinal cord has been described in animal models of spina bifida after the failure of closure during embryonic life. Still, its association with neuroinflammatory processes is poorly understood. In this review, we will discuss the current understanding of neuroinflammation in neural tube defects, specifically spina bifida, and highlight inflammation-targeted strategies that may potentially be used to treat this pathophysiological condition

Properties of calcium carbonate/mica and calcium carbonate/talc filled polypropylene composites

Mineral fillers namely talc, calcium carbonate, mica, glass and carbon fibers are the common fillers used in plastic industry that can alter thermoplastic properties. With the incorporation of fillers, significant outcome can be observed especially in the mechanical properties of polymer composites produced apart from its rigidity and resistance to temperature. Properties of single and hybrid fillers filled polypropylene (PP) composites were studied in this research work. Mineral fillers such as talc, mica and calcium carbonate (CaCO) were incorporated into PP composites. Realizing the advantage of each mineral filler, the effect of hybrid fillers; CaCO/Talc (CC/T) and CaCO/Mica (CC/M) at 40 wt% were investigated. Generally, the results demonstrated that CC/M has higher tensile modulus than CC/T and both hybrids composites did not give significant effect on the tensile strength. Thermogravimetric analysis (TGA) results revealed that CC/M increased thermal stability of PP composites when compared to CC/T. Flammability testing on PP hybrid composites was carried out where lower burning rate indicates better flammability. From the results, it shows that CC/M system have better flammability compared to CC/T system

Study of the effect of different shapes of ultrafine silica as filler in natural rubber compounds

The effects of different particle shapes of ultrafine silica used as a filler on the properties of natural rubber compounds were investigated. Three shapes of filler (cubical, elongated and irregular) were produced using the Hosokawa Alpine classifier mode with a 50 ATP-forced vortex classifier. Each filler was loaded into SMR-L natural rubber at four different loadings, 10 to 40 parts per hundred rubber (phr). The curing characteristics, tensile properties and morphology were studied to measure the performance of the filler. Variations of the particle shape of ultrafine silica did not affect the scorch time and cure time of natural rubber compounds. However, at higher loading, elongated-shaped filler showed a higher maximum torque compared with cubical or irregular shaped fillers. Because of better filler-rubber interaction, irregular shaped fillers showed the highest tensile strength, elongation at break and hardness compared with the cubical and elongated shapes

VertiMill® - development of circuit survey and performance evaluation protocols

Approximately 420 VertiMills® (VTM) have been installed in mineral processing plants throughout the world, mainly in tertiary and regrind applications plus several in secondary grinding duties. Metso Minerals (Metso) and the Julius Kruttschnitt Mineral Research Centre (JKMRC) have commenced a collaborative research program in stirred milling technology focusing on mill performance evaluation, model development and scale-up methodology. Industrial VTMs are being assessed using a consistent circuit survey protocol to evaluate the performance of VTMs in comminution circuits. The survey protocol includes identification and modification of sampling points, appropriate sampling techniques, controlled circuit stability, and best sample analysis practice. To initiate this study four surveys were conducted in the tertiary grind circuit in the Ridgeway Concentrator at Cadia Valley Operations (CVO) that treats the full circuit throughput of over 800 tph. To deal with the high feed rate the site opted to lead the world in the application of stirred mills by installing the largest VTM, at 3000 hp (2240kW) in closed circuit with a hydrocyclone bank. On average the operating work index was 13.1 kWh/t, reducing the secondary grind product by 40 - 50 µm to the required 80 to 100 µm range. The applied specific energy is relatively low in these low-intensity stirred media mills at 2.7 kWh/t. The size specific energy was 24.2 kWh/t-75µm. Based on the survey and operating data the VTM circuit is performing well in this high-throughput tertiary grinding application, producing a sub-100µm product

New Insights into Segmental Packing, Chain Dynamics and Thermomechanical Performance of Aliphatic Polyurea Composites: Comparison between Silica Oxides and Titanium (III) Oxides

Polyurea (PU) is intrinsically reinforced by its microphase-separated morphology, giving its excellent mechanical properties. In this study, it is shown how a high-index PU formulation applies easy diffusion of hard segments into the soft phase of the PU matrix and tune its chain mobility. Moreover, the interaction of micro (>100 nm), nano (<100 nm) fillers with the microdomains and their thermomechanical properties are unraveled. Herein, nanosilica oxide (NS) and micro titanium (III) oxide (Ti2O3) are incorporated at low loadings into a solvent-free two-component aliphatic PU via insitu polymerization. While NS achieves an interfacial interaction with urea groups and forms a tight hard segmental packing, the large-sized Ti2O3 assembles the interconnected PU chain network, improving its crystallinity. Strong reinforcement by NS is noticed when tensile strength increased from 26 to 31 MPa and on the maximum thermal degradation temperature by 21 °C increment from the neat PU. In contrast, the soft segmental dynamics are triggered with the presence of Ti2O3 as indicated in the reduction in glass transition temperature and the 288% improvement in the storage modulus. This study provides an insightful perspective in designing robust PU composites, effective for myriad applications including strong and flexible films in circuit boards and photovoltaic (PV) cells