11 research outputs found
Folate Production by Probiotic Bacteria
Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA) and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia
A contribute to the comprehension of complexing agents and salt solutions reaction mechanism on chemical attack of type I molded glass containers
The commonly named ″glass delamination″ that is flakes or particles' appearance in injectables, is an important issue sometime at the origin of recalls from the market and of possible health issues to patients. In a previous work (1) the enhancement of glass surface chemical attack was shown in type I tubing and molded borosilicate glass containers, due to the presence of complexing agents in the aqueous solution in synergy with basic pH. In any case neither flakes development nor cloudy solutions were found also in the present work, to emphasize that flakes development (delamination) is not easily correlated even with a strong glass surface chemical attack. To understand the correlation between complexing agent chemical structure and the rate of glass chemical attack, a few homologue series of carboxylic and dicarboxylic acids were investigated. We considered the presence of functional groups (NH2, COOH, OH), alkyl chain length (3 to 6 carbon atoms) and the presence of double C=C bonds. Testing conditions were performed at 0.024M constant concentration, in the 5.8 - 10 pH range, in small-volume 23 mL type I molded glass containers, by autoclaving for 1 h at 121 °C according to the European Pharmacopoeia or United States Pharmacopoeia. The extracted silicon was analyzed by inductively coupled plasma atomic emission spectrometry. The collected data confirm that both dissociation constant pKa and molecular structure of the complexing agent are determinant enhancing factors of glass surface chemical attack. The second part of the work concerns with the glass surface chemical attack in the 5.8 - 9 pH range by alkali chloride solutions (NaCl and KCl 0.9% w/v and 0.0154M) widely used in parenteral therapies. For reason of completeness, this last research was extended also to LiCl and CsCl even if not used in injectables, to evaluate a possible influence of the molecular weight on the glass chemical attack. A correlation between alkali chlorides molecular weight and glass chemical attack as a function of pH was found. Therefore, in a preliminary way also acetic acid and EDTA (ethylenediaminetetraacetic acid) complexing power were examined in presence of Na or Li ions, showing some different chelating propensity as a function of the alkali ion. The present research can give precious information to the chemist involved in new pharmaceutical formulation or new molecules development, to prevent or consider some possible compatibility limitation with the packaging in type I borosilicate glass containers
Orthodontic miniscrews: An experimental campaign on primary stability and bone properties
Objective: To evaluate the primary stability of different shaped miniscrews through the acquisition
of data regarding maximum insertion torque, pullout force, and a radiodiagnosic evaluation of
bone characteristics.
Materials and methods: Sixty fresh porcine bone samples were scanned by computed tomography
(CT) and cone-beam computed tomography (CBCT). By means of a dedicated software, CT and
CBCT images were analysed to measure the insertion-site cortical thickness, cortical density, and
marrow bone density. Sixty miniscrews of 12 different types were implanted with no predrilling pilot
hole in the bone samples. Every device was tightened by means of a digital torque screwdriver and
torque data were collected. Subsequently, pullout tests were performed. Spearman and Pearson
correlations were employed to compare any relationship between continuous variables.
Results: Different types of miniscrews did not show statistically significant differences in their
torque value (P = 0.595), instead a significant difference was revealed by considering their load
measures (P = 0.039). Cortical bone thickness resulted strongly correlated both with value of load
(P < 0.001), and modestly with torque measures (P = 0.004). A strong positive correlation was found
between CT and CBCT both for cortical density (P < 0.001) and marrow bone density (P < 0.001).
Conclusion: Bone characteristics play the major role in miniscrews primary stability
On the stability efficiency of anchorage self-tapping screws: Ex vivo experiments on miniscrew implants used in orthodontics
Background: The clinical success of orthodontic miniscrews is strictly related to primary stability, which depends on bone viscoelastic properties too. In this study, we evaluated the short time mechanical response of native bone to miniscrews, by a laboratory test based on dynamic loading. Methods: Thirty-six segments of porcine ribs were first scanned by cone-beam computerized tomography to obtain insertion-site cortical thickness, cortical and marrow bone density. Twelve different types of miniscrews were implanted in the bone samples to evaluate the elastic compliance of the implants in response to a point force applied at the screw head normally to the screw axis. The compliance was measured dynamically in a Dynamic Mechanical Analysis apparatus as the Fourier Response Function between the signals of displacement and force. The measurements were repeated in five days successive to the insertion of the miniscrew. Findings: The elastic compliance was positively related to observation timepoints, but it was not related neither to the screw type nor to the value of the insertion torque. Interpretation: Stability behavior is significantly related to the short time response of native bone rather than to the screw design or the insertion torque values
Immobilization of iron rich steel industry waste and products characterization
The steel industry produces large amount of wastes, some of which are today used in other industrial
sectors; iron oxide rich wastes are difficult to recycle and vitrification is one of the most efficient
techniques to stabilize them and produce materials suitable for new applications. The waste considered
in this study comes from the purification of fumes captured by hoods during agglomeration process in the
sinter plant. These dusts have been vitrified on a laboratory scale by the addition of glass cullet coming
from diversified harvest of municipal waste, varying the glass/dust ratio from 80:20 to 50:50. The as
produced materials have been characterized by means of XRD analysis and SEM images, and leaching
tests have been carried out to evaluate their chemical stability. The electrical and magnetic properties of
these iron rich materials have been evaluated too. The resistivity of the samples produced with 45% and
50% of waste are 20 and 1.5
103V m respectively, considerably lower than the common soda-lime glass
resistivity value (1012V m). Moreover the materials show a ferromagnetic behaviour; the Curie
Temperature of the materials lies in the range from T = 395 C to T = 533 C, confirming the presence of
magnetite/maghemite phases
Dental arch response to Haas-type rapid maxillary expansion anchored to deciduous vs permanent molars: A multicentric randomized controlled trial
Objective: To assess maxilla and mandibular arch widths' response to Haas-type rapid maxillary expansion (RME) anchored to deciduous vs permanent molars on children with unilateral posterior crossbite. Materials and Methods: Seventy patients with unilateral posterior crossbite recruited at the Universities of Genova, Siena, and Insubria (Varese) were randomly located into GrE (RME on second deciduous molars) or Gr6 (RME on first permanent molars) and compared. Results: Upper intermolar distance and permanent molar angulation increased significantly in Gr6 vs GrE at T1. Upper intercanine distance increased significantly in GrE vs Gr6 at T1 and T2. GrE showed significant increases for upper intermolar and upper intercanine widths. Gr6 showed statistically significant increases for upper intermolar widths, for upper and lower intercanine widths, and for increases of angulation of upper and lower permanent molars. Conclusions: GrE showed reduced molar angulation increases at T1 and reduced molar angulation decreases at T2 when compared with Gr6. At T2, the net increase of the upper intercanine distance in GrE was still significant compared with Gr6, indicating a more stable expansion in the anterior area
Progetto per il concorso internazionale per il waterfront di La Spezia.
Progetto per il concorso internazionale per il waterfront di La Spezia.
Progetto:
Jose Maria Tomas Llavador, Studio Schiattarella, Aldo Mazzanobile
Consulenti:
Mario Manfroni (progetto urbano)
Christian Rocchi (progetto urbano)
Valeria Caramagno (verde)
Maria Emanuela Lo Monaco (pr.financing)
Exa Engineering (strutture e op.marittime)
Patrizia Burlando (paesaggio)
Collaboratori:
Pilar Martì Rodrigo, Paola Schiattarella, Fabrizio Battistelli, Daniela Biavati, Gianluca Bilotta, Gabriele Cossetto, Emidio Di Nicola, Alberto Greti, Ernesto Iacangelo, Sabrina Leone, Carla Maresca, Angela Pizzuti, Alessandra Rapaccini, Alberto Riccioni, Giacomo Sanna, Giorgia Semprini, Vicenç Ferrer