Ozone in Lombardy: Years 1998-1999

Photochemical pollutants, especially ozone, have reached very high levels in Lombardy in recent years, with peaks of up to 150 ppb in late spring and summer. Lombardy, lying on the Po Plain, supports a large number of cities and industries and these, along with heavy traffic, produce copious amounts of primary pollutants such as nitrogen oxides and numerous volatile organic compounds. Furthermore, the peculiar orography of this region fosters the stagnation of air masses on a basin-scale and the presence of diurnal breezes towards northern areas, along with the evolution of the Mixing Layer, spread the polluted air masses over a large territory. Numerous stations in Lombardy give the concentrations of ozone and of nitrogen oxides. In this paper, ozone measurements carried out at the plain area around Milan and at pre-alpine sites in the spring and summer 1998 and 1999 will be shown and discussed, focusing on the months of May and July. The study of temporal and spatial behaviour of ozone goes hand in hand with the analysis of the Boundary Layer’s evolution. A number of radon stations were operating in Milan and in other sites in Lombardy. Measurements of atmospheric concentrations of radon yield an index of atmospheric stability, of the formation of thermal inversion, of convective turbulence, and of the movement of air masses, and hence they are very relevant to the understanding of the conditions of atmospheric pollutants

Control of targeting ligand display by pH-responsive polymers on gold nanoparticles mediates selective entry into cancer cells

Selective targeting of cells for intracellular delivery of therapeutics represents a major challenge for pharmaceutical intervention in disease. Here we show pH triggered receptor-mediated endocytosis of nanoparticles via surface ligand exposure. Gold nanoparticles were decorated with two polymers: a 2 kDa PEG with a terminal folate targeting ligand, and a di-block copolymer including a pH-responsive and a hydrophilic block. At the normal serum pH of 7.4, the pH-responsive block (apparent pKa of 7.1) displayed a hydrophilic extended conformation, shielding the PEG-folate ligands, which inhibited cellular uptake of the nanoparticles. Under pH conditions resembling those of the extracellular matrix around solid tumours (pH 6.5), protonation of the pH-responsive polymer triggered a coil-to-globule polymer chain contraction, exposing folate residues on the PEG chains. In line with this, endocytosis of folate-decorated polymer-coated gold nanoparticles in cancer cells overexpressing folate receptor was significantly increased at pH 6.5, compared with pH 7.4. Thus, the tumour acidic environment and high folate receptor expression was effectively exploited to activate cell binding and endocytosis of these nanoparticles. These data provide proof-of-concept for strategies enabling extracellular pH stimuli to selectively enhance cellular uptake of drug delivery vectors and their associated therapeutic cargo

Association between teeth agenesis and Angle’s classes in an Italian population

BACKGROUND: Teeth agenesis or hypodontia consists of the developmental absence of one or more teeth. Many studies confirm that this condition is almost frequent in general population; the prevalence reported is between 2.7% and 11.3%. This condition shows a multifactorial etiology: genetic factors, hereditary factors, environmental factors, local or general infective processes, radiations, drugs and traumas. The aim of this observational study was to evaluate the prevalence of tooth agenesis in a sample of orthodontic healthy patients considering each Angle malocclusion. METHODS: Nine hundred patients from a University clinic and three private practices were analyzed through intra and extra oral photographs, orthodontic study casts, panoramic radiographs and lateral cephalograms. The following inclusion criteria were applied: non-syndromic patients, without previous orthodontic, prosthetic treatment or extractions. Patients’ clinical data consisted in general and dental anamnesis, intra and extra oral photographs, orthodontic study casts, digital panoramic radiographs and lateral cephalograms. The whole sample was divided into four groups (A-B-C-D) in relation with Angle’s malocclusion and dental agenesis registered. RESULTS: The whole sample presented a mean prevalence of the condition of 8.80%. Class II/2 is the most affected malocclusion with 20.37% of the patients affected by the condition, followed by class III (11.19%), class II/2 (8.05%) and class I (6.62%). The χ2 test demonstrated a statistically significant different distribution of the condition between the four groups (P value =0.0059). The four groups presented also different patterns of missing teeth. CONCLUSIONS: We found a significantly different distribution of the condition in the different malocclusions with class II/2 presenting the higher prevalence of tooth agenesis (20.37%). The most frequent teeth affected by agenesis in the entire sample are respectively: mandibular second premolars (32.40%), followed by the maxillary lateral incisors (27.70%) and the maxillary second premolars (15.50%)

Development of non-destructive-testing based selection and grading strategies for plantation Eucalyptus nitens sawn boards

Stiffness is considered one of the most important structural properties for sawn timber used in buildings and laminated structures including mass timber elements. There is great potential to use plantation Eucalyptus timber for structural applications, and the successful development of a plantation timber supply chain for structural products will depend on the accurate selection and grading of the resource. In this study we aimed to investigate the suitability of non-destructive testing (NDT) to improve selection and grading of sawn boards sourced from a young E. nitens plantation. We studied 268 sawn boards traced from the tree through to final processing stages. We found high and positive correlations between stiffness (measured as dynamic modulus of elasticity) tested at each board processing stage through acoustic wave velocity (AWV) and the static board modulus of elasticity measured through mechanical testing on dressed boards. Position of the board in the stem and sawn board processing treatment significantly impacted board modulus of elasticity, indicating that early selection of logs would allow larger yield of stiffer boards. We investigated the grading of boards through the traditional Australian Standards using a visual-grading system and through AWV, finding a classification error of 82.5% and 45.2%, respectively. We developed a linear model which was used to re-classify the boards, obtaining a smaller classification error, including fewer boards being over-graded. Our results demonstrate that AWV can be used as an early selection method for structural boards and can also be employed to satisfactorily grade E. nitens plantation boards to be used in building structures and as elements of mass timber

Prevalence and patterns of tooth agenesis in Angle class II division 2 malocclusion in Italy: A case-control study

Objective: The aim of this case-control retrospective study was to assess the prevalence and pattern of tooth agenesis in a group of Italian Caucasian test subjects with Class II division 2 malocclusion. The findings were then compared with an Italian control group of orthodontic patients and with previous studies performed in other countries. Material and method: Six hundred patients (37 subjects with Angle Class II division 2 malocclusion and 563 orthodontic patients with other malocclusions), aged 7 or older, from the Orthodontic Department of University of Padua Dental Clinic were collected. For this investigation, two expert operators evaluated the Angle Class from dental casts, intraoral photographs and lateral cephalograms. Inclusion criteria for Class II division 2 were: U1-SN less than 90\ub0 and overbite > 3 mm. Tooth agenesis were assessed with digital panoramic radiographs. Third molars were excluded from the analysis. Descriptive analysis using absolute and relative frequencies were performed to check out the prevalence and pattern of tooth agenesis in the sample considered. The relative frequencies in each table were calculated as a percentage based from column total. Results: The prevalence of tooth agenesis in the Angle Class II division 2 group was 18.92%, while in the general population was 8.35%. This result was sufficient to demonstrate a significant difference between the two groups concerning the tooth agenesis prevalence (P-value < 0.05). Conclusion: Prevalence of permanent tooth agenesis was more than 2 times higher in the Class II division 2 group rather than in the control group. No agenesis of maxillary lateral incisors was found in Class II division 2 group

Vestibular and lingual orthodontics: Experimental study on plaque and blood indexes

BACKGROUND: In patients with fixed orthodontic treatment, good oral hygiene management is important to prevent complications such as caries, enamel demineralization, white spots, gingivitis, gingival hyperplasia and periodontitis. The aim of this experimental study is to compare the plaque and gingival indexes in patients with labial or lingual appliances. METHODS: Twenty patients with a mean age of 27\ub1-4.95 years were selected; ten patients (eight females and two males) between 17 and 39 years were fitted with a labial appliance while ten patients (nine females and one male) between 16 e 36 years were fitted with a lingual appliance. The dental hygienist made an evaluation using the plaque index and the gingival index, motivated and instructed the patients with labial and lingual devices to perform correct home oral hygiene. The timepoint were the following: T0 before the bonding, T1 one month after the bonding, T2 three months after the bonding, T3 six months after the bonding. RESULTS: In the vestibular appliance at T0, the plaque index is significantly lower than the lingual device, but the bleeding index is significantly higher. Moreover, in both treatments, an increase in the parameters from T0 to T1, T2 and T3 was confirmed, and in the latter a linear increase trend both in the plaque index and in the gingival index can be observed. CONCLUSIONS: The plaque and bleeding index increase gradually from T0 to T3, but there is no significant difference between the vestibular and lingual appliances

Screening of chemical linkers for development of pullulan bioconjugates for intravitreal ocular applications

The treatment of posterior segment disorders of the eye requires therapeutic strategies to achieve drug effects over prolonged times. Innovative colloidal delivery systems can be designed to deliver drugs to the retina and prolong their intravitreal permanence. In order to exploit pullulan (Pull) as polymeric drug carrier for intravitreal drug delivery, derivatives of hydrophobic model molecule rhodamine B (RhB) were conjugated to the pullulan backbone through linkers with different stability, namely ether (Et), hydrazone (Hy) or ester (Es) bond to obtain Pull-Et-RhB, Pull-Hy-RhB and Pull-Es-RhB, respectively. Dynamic light scattering and transmission electron microscopy analyses showed that the polymer conjugates self-assembled into 20-25 nm particles. Pull-Et-RhB was fairly stable at all tested pH values. At the vitreal pH of 7.4, 50% of RhB was released from Pull-Hy-RhB and Pull-Es-RhB in 11 and 6 days, respectively. At endosomal pH (5.5), 50% of RhB was released from Pull-Hy-RhB and Pull-Es-RhB in 4 and 1 days, respectively. Multiple particle tracking analyses in ex vivo porcine eye model showed that the diffusivity of the bioconjugates in the vitreous was about 103 times lower than in water. Flow cytometry and confocal microscopy analyses showed that bioconjugates are remarkably taken up by the retinal RPE cells. In vivo studies showed that after intravitreal injection to mice, the bioconjugates localize in the ganglion cell layer and in the inner and outer plexiform layers. Pull-Hy-RhB particles were detected also inside the retinal blood vessels. These results demonstrate that pullulan with tailored linkers for drug conjugation is a promising vehicle for long-acting intravitreal injectables that are capable to permeate to the retina