In vitro evaluation of an air-abrasion cavity preparation system (KCP 2000) for bonded restorations

Thesis (M.Sc.D.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1995 (Pediatric Dentistry).Includes bibliographical references (leaves 97-101).This study tested a new air-abrasive system (KCP 2000, American Dental Technologies, Troy, MI) as a substitute for acid etching to condition enamel and dentin surfaces for sealants and bonded composite restorations. Thirty specimens were tested for shear bond strength of composite to enamel surface conditioned with: 1) 10% maleic acid, 15 sec. (control); 2) air-abrasion at 120 psi and 50 [mu]m particle size, 3 sec.; and 3) air-abrasion plus maleic acid. Thirty specimens were tested for composite shear bond strength to dentin conditioned with: 4) 10% maleic acid, 15 sec. (control); 5) air-abrasion at 120 psi and 50 [mu]m particle size, 3 sec.; and 6) air-abrasion plus maleic acid. Thirty specimens were tested for shear bond strength of sealant to enamel surface conditioned with: 7) 37% orthophosphoric acid, 60 sec. (control); 8) air-abrasion at 120 psi and 50[mu]m particle size, 3 sec.; and 9) air-abrasion plus orthophosphoric acid. Marginal microleakage of twelve molars with a class V composite restoration prepared with a 330 high speed bur and conditioned with 10% maleic acid was compared to eleven molars with a class V composite restoration prepared with air-brasion at 160 psi and 27 [mu]m particles size and conditioned at 120 psi and 50 [mu]m particle size. All the samples from microleakage and shear bond strength tests were thermocycled for 300 cycles between 5[degrees]C and 60[degrees]C[plus or minus]2[degrees] with a dwell time of 30 sec. and transfer time of 15 sec. The shear bond strength results were recorded in MPa and were as follows: Composite to enamel, group 1: 10.7[plus or minus]3.6, group 2: all specimens failed before the shear bond strength test, group 3: 14[plus or minus]1.9; Composite to dentin, group 4: 18.5[plus or minus]5.1, group 5: 3.1[plus or minus]2.0, group 6: 11.1[plus or minus]5.8; Sealant to enamel, group 7: 7.5[plus or minus]2.0, group 8: 0.3[plus or minus]0.1, group 9: 9.7[plus or minus]3. The ANOVA test and Scheffe Pairwise Comparisons tests for the composite to dentin group showed that the acid etching was significantly stronger than the air-abrasion treatment alone, but equivalent to the air-abrasi6n plus the acid etching (p[less than or equal to]0.01). The student t-test applied to the sealant to enamel group revealed that bond strength with acid etching was significantly higher than air-abrasion (p[less than]0.001). The mean marginal microleakage values (mm) were as follows: Air-abrasion group, occlusal site: 0.75[plus or minus]0.2, cervical site: 0.7[plus or minus]0.4; 330 bur group, occlusal site: 0.46[plus or minus]0.2, cervical site: 0.86[plus or minus]0.4. The ANOVA and Scheffe Pairwise Comparisons tests showed a significantly higher microleakage in the cervical site of the 330 bur group (p[less than or equal to]0.01). This study showed that the air-abrasive technique can be effective for bonding when used in conjunction with acid etching but it cannot be used as a sole conditioner prior to bonding composite or sealant to enamel or dentin

Area of intrinsic graphs in homogeneous groups

We establish an area formula for computing the spherical measure of an intrinsic graph of any codimension in an arbitrary homogeneous group. Our approach only assumes that the map generating the intrinsic graph is continuously intrinsically differentiable. The important novelty lies in the notion of Jacobian, which is built by the auxiliary Euclidean distance. The introduction of this Jacobian allows the spherical factor to appear in the area formula and enables explicit computations.Comment: 46 page

Ormoni, psiche e modulazione dell’umore: quando il ginecologo conta

Gli steroidi sessuali agiscono fisiologicamente in maniera estremamente potente sul sistema nervoso centrale e le fluttuazioni degli stessi contribuiscono alla fisiopatologia di tutta una serie di disturbi adattativi che trovano nel sesso femminile un bersaglio preferenziale. Nel sesso femminile gli estrogeni sono di primaria importanza non solo nel controllo nella funzione riproduttiva, ma svolgono tutta una serie di ulteriori complesse azioni biologiche. Infatti, tramite la regolazione del rilascio di neurotrasmettitori e neuropeptidi regolano, a livello ipotalamico, l’attività di centri deputati al controllo della riproduzione, della termoregolazione, della sazietà, della pressione arteriosa, ecc. e sono coinvolti, a livello del sistema limbico, nella regolazione del tono dell’umore, del comportamento e del benessere psicofisico. Durante il periodo climaterico la riduzione degli steroidi ovarici si associa con un’alterazione del turnover dei classici neurotrasmettitori e ad una ridotta attività dei neuropeptidi coinvolti nella modulazione funzionale del SNC. Di recente l’attenzione si è focalizzata anche sullo studio delle variazioni dei neurosteroidi in postmenopausa e sull’impatto che i vari tipi di terapia ormonale sostitutiva esercitano sul milieu neuroendocrino

Omics-based monitoring of microbial dynamics across the food chain for the improvement of food safety and quality

The diffusion of high-throughput sequencing has dramatically changed the study of food microbial ecology. Amplicon-based description of the microbial community may be routinary implemented in the food industry to understand how the processing parameters and the raw material quality may affect the microbial community of the final product, as well as how the community changes during the shelf-life. In addition, application of shotgun metagenomics may represent an invaluable resource to understand the functional potential of the microbial community, identifying the presence of spoilage-associated activities or genes related to pathogenesis. Finally, retrieving Metagenome-Assembled Genomes (MAGs) of relevant species may be useful for strain-tracking along the food chain and in case of food poisoning outbreaks. This review gives an overview of the possible applications of sequencing-based approaches in the study of food microbial ecology, highlighting limitations that still prevent the spreading of these techniques to the food industry

Specific Microbial Communities Are Selected in Minimally-Processed Fruit and Vegetables according to the Type of Product

Fruits and vegetables (F&V) products are recommended for the daily diet due to their low caloric content, high amount of vitamins, minerals and fiber. Furthermore, these foods are a source of various phytochemical compounds, such as polyphenols, flavonoids and sterols, exerting antioxidant activity. Despite the benefits derived from eating raw F&V, the quality and safety of these products may represent a source of concern, since they can be quickly spoiled and have a very short shelf-life. Moreover, they may be a vehicle of pathogenic microorganisms. This study aims to evaluate the bacterial and fungal populations in F&V products (i.e., iceberg lettuces, arugula, spinaches, fennels, tomatoes and pears) by using culture-dependent microbiological analysis and high-throughput sequencing (HTS), in order to decipher the microbial populations that characterize minimally-processed F&V. Our results show that F&V harbor diverse and product-specific bacterial and fungal communities, with vegetables leaf morphology and type of edible fraction of fruits exerting the highest influence. In addition, we observed that several alterative (e.g., Pseudomonas and Aspergillus) and potentially pathogenic taxa (such as Staphylococcus and Cladosporium) are present, thus emphasizing the need for novel product-specific strategies to control the microbial composition of F&V and extend their shelf-life

Safety and efficacy of tranexamic acid for prevention of obstetric haemorrhage. An updated systematic review and meta-analysis

Background. A number of clinical systematic review and meta-analysis have been published on the use of tranexamic in the obstetric setting. The aim of this meta-analysis was to evaluate the safety and effectiveness of tranexamic acid in reducing blood loss when given prior to caesarean delivery. Materials and methods. We searched the Cochrane Wounds Specialized Register, Cochrane Central, MEDLINE (through PUBMED), Embase, and SCOPUS electronic databases. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists to identify additional studies. We used no restrictions with respect to language and date of publication. Two review authors independently performed study selection, "Risk of bias" assessment, and data extraction. Initial disagreements were resolved by discussion, or by including a third review author when necessary. Results. We found 18 randomised controlled trials (RCTs) that met our inclusion criteria. Overall, 1,764 women receiving intravenous tranexamic acid for prevention of bleeding following caesarean sections and 1,793 controls receiving placebo were enrolled in the 18 RCTs evaluated. The use of tranexamic acid compared to controls (placebo or no intervention) reduces post-partum haemorrhage >400 mL (risk ratio [RR] 0.40, 95% confidence interval [CI] 0.24-0.65; 5 trials with a total of 786 participants), severe post-partum haemorrhage >1,000 mL (RR 0.32, 95% CI: 0.12-0.84; 5 trials with a total of 1,850 participants), and need for red blood cell transfusion (RR 0.30, 95% CI: 0.18-0.49; 10 trials with a total of 1,873 participants). No particular safety concerns on the use of this antifibrinolytic agent emerged from the analysis of the 18 RCTs included. Discussion. Overall, the results of this meta-analysis support the evidence of a beneficial effect of tranexamic acid in reducing blood loss and need for blood transfusion in pregnant women undergoing caesarean section

Area formula for regular submanifolds of low codimension in Heisenberg groups

We establish an area formula for the spherical measure of intrinsically regular submanifolds of low codimension in Heisenberg groups. The spherical measure is computed with respect to an arbitrary homogeneous distance. Among the arguments of the proof, we point out the differentiability properties of intrinsic graphs and a chain rule for intrinsic differentiable functions.Comment: 27 page

Natural fibers insulation panels: an adaptive production

The research team recently developed an innovative system with low environmental impact for the production of semi-rigid panels for thermal and acoustic insulation, obtained from recycled sheep's wool from Piemonte region. Starting from the previous work, a new semi-rigid panel has been produced, combining sheep wool with hemp technical fibers. Both sheep wool and hemp comes from agri-food systems and are considered as a wastes from existing production chains. Panels show low environmental impact and stiffness as main innovative features, if compared with other similar products on the market. A further experimentation phase allowed to improve the production process adaptability degree to the availability of natural by-products from local agri-food systems, with the aim to develop an “open recipe” able to answer to the building market different requests. The contribution presents the methodology adopted for the research in progress, the "open" technology assessment adopted for panels production and results of preliminary thermal tests