The Importance of Nitrogen in the Heat Treating of Ferrous and Non-Ferrous Metals and Alloys

Nitrogen was first used as the base gas for treating and annealing semifinished products of steel. Since then the use of industrial gases has spread to cover the full range of heat treatment processes for ferrous and non-ferrous metals and alloys. This paper is focused on titanium and titanium alloys nitriding but also on the recommended nitrogen process atmosphere for ferrous and non-ferrous metals and alloys

Hematite. Processing and Applications

In the paper are shown the history, processing and applications of hematite. Hematite is an oxide of iron having the composition Fe2O3. Pure hematite, also called “red ore” contains 70% Fe. Manufacturing processes for steel are made in furnaces (open hearth, Bessemer processes, oxygen furnace, electric arc furnaces). Hematite is used both as an ore of iron and as an industrial mineral in order to produce intermediate products such as: - Sinter; - Pellets; - Pig iron; - Malleable cast iron; - High duty cast iron; - Wrought iron; - Directly reduced iron; - Iron carbide; - Steel

Adhesive-Ceramic Interface Behavior in Dental Restorations. FEM Study and SEM Investigation

The purpose of this study is to identify the stress levels that act in inlay and onlay restorations, according to the direction and value of the external force applied. The study was conducted using the Finite Element Method (FEM) of three types of ceramics: pressed lithium disilicate and monolith, zirconia, and three different adhesive systems: self-adhesive, universal, and dual-cure cements. In addition to FEM, the inlay/onlay-dental structure interface analysis was performed by means of Scanning Electron Microscopy (SEM). The geometric models were reconstructed based on computer tomography images of an undamaged molar followed by geometrical procedures of inducing the inlay and onlay reconstructions. The two functional models were then simulated for different orientations of external force and different material properties, according to the considered adhesives and ceramics. The Scanning Electron Microscopy (SEM) was conducted on 30 extracted teeth, divided into three groups according to the adhesive cement type. Both FEM simulation and SEM investigations reveal very good mechanical behavior of the adhesive-dental structure and adhesive-ceramic interfaces for inlay and onlay reconstructions. All results lead to the conclusion that a physiological mastication force applied, regardless of direction, cannot produce a mechanical failure of either inlay or onlay reconstructions. The adhesive bond between the restorations and the dental structure can stabilize the ceramic restorations, resulting in a higher strength to the action of external forces

Prognostic Potential of Tumor-Infiltrating Immune Cells in Resectable Oral Squamous Cell Carcinoma

(1) Background: The immune microenvironment plays an important role in carcinogenesis and has prognostic potential in many types of cancer. In this study we assess the prognostic character of tumor-infiltrating immune cells CD4+, CD8+ and CD56+ in resectable oral squamous cell carcinoma (OSCC); (2) Methods: We have evaluated the densities of CD4+, CD8+ and CD56+ in two distinct compartments, intratumor and invasion front, in 90 patients with OSCC; (3) Results: Significant differences were found between the tumor compartments for the CD4+ and CD8+ lymphocytes. An improved outcome (OS) was seen in patients with high densities of intratumor CD8+ lymphocytes (p = 0.0086), CD8+ lymphocytes at the front of invasion (p = 0.0011) and for intratumor CD56+ cells (p = 0.0016). Multivariate analysis confirmed the independent prognostic role of CD8+ at the front of invasion (OR = 3.75, CI95% 1.17–12.35, p = 0.026) and for intratumor CD56+ cells (OR = 3.669, CI95% 1.09–15.37, p = 0.035); (4) Conclusions: Tumor-infiltrating CD8+ lymphocytes at the front of invasion and CD56+ in the intratumor compartment display predictive traits in OSCC. A reach immune infiltration with these types of cells is associated with an improved patient outcome

Mechanical and Computational Fluid Dynamic Models for Magnesium-Based Implants

Today, mechanical properties and fluid flow dynamic analysis are considered to be two of the most important steps in implant design for bone tissue engineering. The mechanical behavior is characterized by Young’s modulus, which must have a value close to that of the human bone, while from the fluid dynamics point of view, the implant permeability and wall shear stress are two parameters directly linked to cell growth, adhesion, and proliferation. In this study, we proposed two simple geometries with a three-dimensional pore network dedicated to a manufacturing route based on a titanium wire waving procedure used as an intermediary step for Mg-based implant fabrication. Implant deformation under different static loads, von Mises stresses, and safety factors were investigated using finite element analysis. The implant permeability was computed based on Darcy’s law following computational fluid dynamic simulations and, based on the pressure drop, was numerically estimated. It was concluded that both models exhibited a permeability close to the human trabecular bone and reduced wall shear stresses within the biological range. As a general finding, the proposed geometries could be useful in orthopedics for bone defect treatment based on numerical analyses because they mimic the trabecular bone properties

BOTANICAL AND PHYTOCHEMICAL APPROACH ON PASSIFLORA SPP. – NEW NUTRACEUTICAL CROP IN ROMANIA

It has been performed a complex investigation – morpho-anatomical, physiological, taxonomical and phytochemical one – of Passiflora nutraceutical plants from Hofigal S.A., in the frame of project PN-II-PCCA-2013-4-0995, contract 160 (MAIA)/2014. Anatomic analysis of leaf lamina, petiole and stem, provided data with taxonomical importance, leading to the conclusion that plant material belongs to Passiflora caerulea L., in concordance with world monographers of Passiflora genus: VANDERPLANK (2000) and ULMAN & MacDOUGAL (2004). Physiological investigation referred to the following parameters: coefficient k, leaf area index (LAI), chlorophyll fluorescence, stomatal conductance and yield of green plant biomass. Phytochemical investigation consisted in analyzing active principles (polyphenols, flavonoids) content, in correlation with their antioxidant activity and determination of cytotoxicity of Passiflora extracts in NCTC cell line. At 10-150 µg/ml concentrations, it was recorded a normal cell morphology. At concentrations over 250 µg/ml, the plant extract become cytotoxic, altering the cell membrane structure, cells viability and proliferation