Effect of energy and protein level in complete feed used elephant grass (Pennisetum purpureum, Schum.) and maize stover (Zea mays. L) silage on nutrient content, total digestible nutrient, and in vitro degradation

The purpose of this research was to determine of ideal ration of energy and protein in complete feed used elephant grass and maize stover silage. The materials were use elephant grass, maize stover silage with 10% molasses and Lactobacillus plantarum 1x106 CFU/g and concentrates. The method used experimental laboratory, the data of nutrient and TDN content using descriptive analysis. In vitro degradation value was analysed by Analysis of Variance from a factorial randomized block design and followed by Duncan’s Multiple Range Test. The complete feed was use 12.5% elephant grass + 37.5% maize stover silage + 50% concentrates with consist of energy level (E1 =12.5, E2 =13.5, E3 =14.5 MJ/kg DM) and protein level (P1 =10.5, P2= 13.5, P3= 16.5%). The results showed that in vitro DM and OM degradation respectively energy or protein level showed has significantly (P<0.01), while the interaction did not significant (P>0.05). The best treatment is E3P3 with energy 14.5 MJ/kg and protein 16.5% on nutrient content DM 92,51%., OM 90,33%., CP 16.57%, CF 19.29%, EE 1.77%, NFE 53.70%, TDN content 67.14%, In vitro DM degradation 66.14 % and in vitro OM degradation 70.01%.

Biocompatibility and Degradation Behavior of Molybdenum in an In Vivo Rat Model

The biocompatibility and degradation behavior of pure molybdenum (Mo) as a bioresorbable metallic material (BMM) for implant applications were investigated. In vitro degradation of a commercially available Mo wire (ø250 µm) was examined after immersion in modified Kokubo’s SBF for 28 days at 37 °C and pH 7.4. For assessment of in vivo degradation, the Mo wire was implanted into the abdominal aorta of female Wistar rats for 3, 6 and 12 months. Microstructure and corrosion behavior were analyzed by means of SEM/EDX analysis. After explantation, Mo levels in serum, urine, aortic vessel wall and organs were investigated via ICP-OES analysis. Furthermore, histological analyses of the liver, kidneys, spleen, brain and lungs were performed, as well as blood count and differentiation by FACS analysis. Levels of the C-reactive protein were measured in blood plasma of all the animals. In vitro and in vivo degradation behavior was very similar, with formation of uniform, non-passivating and dissolving product layers without occurrence of a localized corrosion attack. The in vitro degradation rate was 101.6 µg/(cm2·d) which corresponds to 33.6 µm/y after 28 days. The in vivo degradation rates of 12, 33 and 36 µg/(cm2·d) were observed after 3, 6 and 12 months for the samples properly implanted in the aortic vessel wall. This corresponds with a degradation rate of 13.5 µm/y for the 12-month cohort. However, the magnitude of degradation strongly depended on the implant site, with the wires incorporated into the vessel wall showing the most severe degradation. Degradation of the implanted Mo wire neither induced an increase in serum or urine Mo levels nor were elevated Mo levels found in the liver and kidneys compared with the respective controls. Only in the direct vicinity of the implant in the aortic vessel wall, a significant amount of Mo was found, which, however, was far below the amounts to be expected from degrading wires. No abnormalities were detected for all timepoints in histological and blood analyses compared to the control group. The C-reactive protein levels were similar between all the groups, indicating no inflammation processes. These findings suggest that dissolved Mo from a degrading implant is physiologically transported and excreted. Furthermore, radiographic and µCT analyses revealed excellent radiopacity of Mo in tissues. These findings and the unique combination with its extraordinary mechanical properties make Mo an interesting alternative for established BMMs.

Development of an Autochthonous Microbial Consortium for Enhanced Bioremediation of PAH-Contaminated Soil

The main objectives of this study were to isolate bacteria from soil chronically contaminated with polycyclic aromatic hydrocarbons (PAHs), develop an autochthonous microbial consortium, and evaluate its ability to degrade PAHs in their native contaminated soil. Strains with the best bioremediation potential were selected during the multi-stage isolation process. Moreover, to choose bacteria with the highest bioremediation potential, the presence of PAH-degrading genes (pahE) was confirmed and the following tests were performed: tolerance to heavy metals, antagonistic behavior, phytotoxicity, and antimicrobial susceptibility. In vitro degradation of hydrocarbons led to the reduction of the total PAH content by 93.5% after the first day of incubation and by 99.22% after the eighth day. Bioremediation experiment conducted in situ in the contaminated area resulted in the average reduction of the total PAH concentration by 33.3% after 5 months and by over 72% after 13 months, compared to the concentration recorded before the intervention. Therefore, this study implicates that the development of an autochthonous microbial consortium isolated from long-term PAH-contaminated soil has the potential to enhance the bioremediation process.

Synthesis of Biobased and Hybrid Polyurethane Xerogels from Bacterial Polyester for Potential Biomedical Applications

Organic–inorganic xerogel networks were synthesized from bacterial poly (3-hydroxybutyrate) (PHB) for potential biomedical applications. Since silane-based networks usually demonstrate increased biocompatibility and mechanical properties, siloxane groups have been added onto polyurethane (PU) architectures. In this work, a diol oligomer (oligoPHB-diol) was first prepared from bacterial poly(3-hydroxybutyrate) (PHB) with an environmentally friendly method. Then, hexamethylene diisocyanate or biobased dimeryl diisocyanate was used as diisocyanate to react with the short oligoPHB-diol for the synthesis of different NCO-terminated PU systems in a bulk process and without catalyst. Various PU systems containing increasing NCO/OH molar ratios were prepared. Siloxane precursors were then obtained after reaction of the NCO-terminated PUs with (3-aminopropyl)triethoxysilane, resulting in silane-terminated polymers. These structures were confirmed by different analytical techniques. Finally, four series of xerogels were prepared via a sol–gel process from the siloxane precursors, and their properties were evaluated depending on varying parameters such as the inorganic network crosslinking density. The final xerogels exhibited adequate properties in connection with biomedical applications such as a high in vitro degradation up to 15 wt% after 12 weeks.

Developing Mg-Zn-Fish Bone Derived Hydroxyapatite Composites for Biomedical Applications: In vitro Degradation Studies

The study of magnesium (Mg) based biomaterials has emerged as a potential research area in recent times. Controlling the rapid corrosion and improving the implant-tissue interface kinetics for better tissue regeneration are the prime interests behind developing novel Mg-based composites. In the current work, the metal matrix composites of Mg-Zn, dispersed with nano-hydroxyapatite derived from fish bones (fHA), were produced by powder metallurgy route. The powders were mixed with the help of ball milling in the presence of ethanol and then sintered at 440 °C. From the microstructural studies, micro-lamellar morphology was noticed for the sintered compacts due to the flake-like morphology of the milled powders. The sintered compacts were then subjected to in vitro biodegradation studies in simulated conditions for one week. From the results, the presence of fHA was found to be highly influential in increasing the rate of mineral deposition on the surface of the composites. These higher mineral depositions protected the surface of the composites from further degradation. The results demonstrate that adding fHA to Mg accelerates biomineralization and controls degradation, leading to better implant-tissue interactions.