Anomalous Diffusion in the Long-Range Haken-Strobl-Reineker Model.

We analyze the propagation of excitons in a d-dimensional lattice with power-law hopping ∝1/r^{α} in the presence of dephasing, described by a generalized Haken-Strobl-Reineker model. We show that in the strong dephasing (quantum Zeno) regime the dynamics is described by a classical master equation for an exclusion process with long jumps. In this limit, we analytically compute the spatial distribution, whose shape changes at a critical value of the decay exponent α_{cr}=(d+2)/2. The exciton always diffuses anomalously: a superdiffusive motion is associated to a Lévy stable distribution with long-range algebraic tails for α≤α_{cr}, while for α>α_{cr} the distribution corresponds to a surprising mixed Gaussian profile with long-range algebraic tails, leading to the coexistence of short-range diffusion and long-range Lévy flights. In the many-exciton case, we demonstrate that, starting from a domain-wall exciton profile, algebraic tails appear in the distributions for any α, which affects thermalization: the longer the hopping range, the faster equilibrium is reached. Our results are directly relevant to experiments with cold trapped ions, Rydberg atoms, and supramolecular dye aggregates. They provide a way to realize an exclusion process with long jumps experimentally.

Impact of COVID-19 on cancer service delivery: a follow-up international survey of oncology clinicians.

BACKGROUND: The COVID-19 pandemic has had a vast impact on cancer service delivery around the world. Previously reported results from our international survey of oncology clinicians, conducted through March-April 2020, found that clinicians reported altering management in both the curative and palliative settings and not in proportion to the COVID-19 case burden in their region of practice. This follow-up survey, conducted from 27th September to 7th November 2020, aimed to explore how attitudes and practices evolved over the 2020 pandemic period. PARTICIPANTS AND METHODS: Participants were medical, radiation and surgical oncologist and trainees. Surveys were distributed electronically via ESMO and other collaborating professional societies. Participants were asked to compare their practice prior to the pandemic to both the period of March-April 2020, referred to as the 'early' period, and the current survey period, referred to as the 'later' period. RESULTS: One hundred and seventy-two oncology clinicians completed the survey. The majority of respondents were medical oncologists (n = 136, 79%) and many were from Europe (n = 82, 48%). In the 'early' period, 88% (n = 133) of clinicians reported altering their practice compared to 63% (n = 96) in the 'later' period. Compared to prior to the pandemic, clinicians reported fewer new patient presentations in the 'early' period and a trend towards more patients presenting with advanced disease in the 'later' period. CONCLUSIONS: Results indicate a swing back towards pre-COVID-19 practices despite an increase in the rate of cumulative COVID-19 cases across 2020. The impact of these changes on cancer associated morbidity and mortality remains to be measured over the months and years to come.

Time- and temperature-dependent migration studies of Irganox 1076 from plastics into foods and food simulants.

The study provides an exhaustive set of migration data for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) from low-density polyethylene (LDPE) in several food matrices. Irganox 1076 was used as a model migrant because it represents one of the typical substances used as an antioxidant in food packaging polymers. Kinetic (time-dependent) migration studies of Irganox 1076 were performed for selected foodstuffs chosen with different physical-chemical properties and in relation to the actual European food consumption market. The effect of fat content and of the temperature of storage on the migration from plastic packaging was evaluated. The results show that migration increased with fat content and storage temperature. All data obtained from real foods were also compared with data obtained from simulants tested in the same conditions. In all studied cases, the kinetics in simulants were higher than those in foodstuffs. The work provides data valuable for the extension of the validation of migration model developed on simulants to foodstuffs themselves.

Cyclotron production of radioactive CeO(2) nanoparticles and their application for in vitro uptake studies.

Nowadays, a wide variety of nanoparticles (NPs) are applied in different fields such as medical science and industry. Due to their large commercial volume, the OECD Working Party on Manufactured Nanomaterials (NMs) has proposed to study a set of 14 nanomaterials, one of which being cerium oxide (CeO(2)). In particular, CeO(2) based NPs are widely used in automotive industry, healthcare, and cosmetics. In this paper, we propose a method for the production of radioactive CeO(2) NPs.We demonstrate that they maintain the same physicochemical characteristics as the "cold" ones in terms of size distribution and Zeta potential; we develop a new protocol to assess their cellular interaction in immortalized mouse fibroblast cell line Balb/3T3, a model for the study of basal cytotoxicity and carcinogenic potential induced by chemicals and in the present case by NPs. Experimental result of this work, which shows a quasi-linear concentration-uptake response of cells, can be useful as a reference dose-uptake curve for explaining effects following biological uptake after exposure to CeO(2) NPs.

Radiolabelling of engineered nanoparticles for in vitro and in vivo tracing applications using cyclotron accelerators.

We present in this article an outline of some cyclotron-based irradiation techniques that can be used to directly radiolabel industrially manufactured nanoparticles, as well as two techniques for synthesis of labelled nanoparticles using cyclotron-generated radioactive precursor materials. These radiolabelled nanoparticles are suitable for a range of different in vitro and in vivo tracing studies of relevance to the field of nanotoxicology. A basic overview is given of the relevant physics of nuclear reactions regarding both ion-beam and neutron production of radioisotopes. The various issues that determine the practicality and usefulness of the different methods are discussed, including radioisotope yield, nuclear reaction kinetics, radiation and thermal damage, and radiolabel stability. Experimental details are presented regarding several techniques applied in our laboratories, including direct light-ion activation of dry nanoparticle samples, neutron activation of nanoparticles and suspensions using an ion-beam driven activator, spark-ignition generation of nanoparticle aerosols using activated electrode materials, and radiochemical synthesis of nanoparticles using cyclotron-produced isotopes. The application of these techniques is illustrated through short descriptions of some selected results thus far achieved. It is shown that these cyclotron-based methods offer a very useful range of options for nanoparticle radiolabelling despite some experimental difficulties associated with their application. For direct nanoparticle radiolabelling, if care is taken in choosing the experimental conditions applied, useful activity levels can be achieved in a wide range of nanoparticle types, without causing substantial thermal or radiation damage to the nanoparticle structure. Nanoparticle synthesis using radioactive precursors presents a different set of issues and offers a complementary and equally valid approach when laboratory generation of the nanoparticles is acceptable for the proposed studies, and where an appropriate radiolabel can be incorporated into the nanoparticles during synthesis.

[The passage from infancy to adolescence and modern family. The role of pediatricians and psychologists]. / Il passaggio dall'infanzia all'adolescenza e la famiglia moderna. Il ruolo del pediatra e dello psicologo.

Currently, the debate on family difficulties during the passage of their children to adolescence gives the responsibility of a positive result in this evolutive process to both children and parents, because their interaction is a common construction, in which they have a role in selecting tools and goals. The pediatrician and the psychologist may give help the family in this critical period for their children.

[School performance: a question that divides. Analysis of learning difficulty]. / Il rendimento scolastico: una questione che divide. Analisi delle difficoltà di apprendimento.

The difficulty of learning is getting always more important, also in relation of a better knowledge of these problems. One factor which has to be taken in consideration as the behaviour of the school.

[They way adolescents live at home]. / Come l'adolescente vive la casa.

The kids, observing the relationship of their parents, are learning from them. Today the home is less home for everyone. At home you are eating, you are learning, especially you are watching a lot of TV. Often there is non a lot of trust between each other. Because of this the conversation is necessary and not the control of the adolescent secretly.

[Adolescence and family life cycle. Role of the pediatrician]. / L'adolescenza e il ciclo di vita della famiglia. Il ruolo del pediatra.

Adolescence observed as one of the step of the life cycle from the point of view of changes in the family. The role of paediatricians in the conversation with the adolescent and his parents is to pay attention to the influence that the whole family system could have on producing symptoms.

[Eating disorders in adolescence: anorexia in children]. / I disturbi alimentari in adolescenza: l'anoressia nel bambino.

When doctor visits adolescents have to pay attention to the massage of body like a mirror of difficulty about growth. Adolescents change their eating habits because they need to distinguish to the family. The doctor have to see first signals of more serious behaviour join to eating: anorexia nervosa.

[Advanced adolescence]. / L'adolescenza avanzata.

The advanced adolescence is the one after the eighteenth birthday. The adolescent tries to accomplish 3 engagements: 1. social and economic stability, 2. the research of a system of values, 3. record of concepts.

[Adolescence and alcohol abuse. Relevance of information given by the pediatrician]. / Gli adolescenti e l'abuso di alcol. L'importanza dell'informazione per il pediatra.

Often we don't see alcohol abuse among adolescents, but this kind of drug, easy to find, could be used to trying their limits. Contemporary group has an important role in the habit of drinking. Often family don't think that it's real problem and it's important that paediatrician grasp this dangerous signals.

[Children are born twice: at birth and in adolescence. The adolescent, his/her parents, and the pediatrician]. / Il bambino nasce due volte: quando viene alla luce e all'adolescenza. L'adolescente, i suoi genitori ed il pediatra.

We know the young's problem often depended to family and to society. In these years we have seen important changes of the family, that is no more a "patriarchal family" but is a "nuclear family". In general we can say that there is a change of the social levels of the family; in particular the Mass-media (especially television-set) are the most important factors responsible of these changes in fact they block the dialogue between family's members. In Italy we can found about 4.500.000 of adolescents (with age between 14 and 20 years). If we observe recent epidemiological data, we can suppose that: about 500.000 of young men have or will have problems that block them to live serenely their adolescence about 70.000 of young men have had a so important problem than they have a psychiatric personality in the future about 4.000 of young men will die for suicide, drugs or for road's incidences. For adolescents is necessary a doctor with multiple competence. We think that this doctor can be pediatrician because he is the doctor that visit children from neonatal age and, for this reason, ha can identify the "family with problems". In conclusion we can say that the pediatrician could say to adolescent's patents that "it is born a new child" with personal idea and with different attitudes, for these reason they must change the rules that they used before puberty because now the same rules are no more valid!

Enhancing implant surgery planning via computerized image processing.

Computerized tomography (CT) and magnetic resolution imaging (MRI) are the medical imaging modalities to deliver cross-sectional images of the human body. In the last decade, CT has become the most frequently used imaging modality for the evaluation of the jaw for dental implants. Furthermore, image reformatting software has been developed in order to obtain a correct preoperative diagnosis and treatment planning regarding osseointegrated implants. Previous work has shown that CT images are affected by a distortion ration from 0% to 6%. This might be due to the alignment of the patient during scanning, to his/her movements, or possibly to the saturation of pixels composing the image. In order to solve the former problem, intraoral stents can be used to center the patient's head perpendicular to the axis of the implant to be inserted. However, if more than one implant must be placed - possibly with very different axes - it would be necessary to acquire the corresponding number of tomograms, each perpendicular to the axis of one planned tooth. Obviously, it would be better not to expose the patient to multiple CT scanning. In this work, we present a software approach for enhancing implants surgery planning in order to obtain exact morphological measurements of the bone and planned teeth with a single CT acquisition. This is achieved by applying image-processing techniques to the original CT images, in order to produce new Ct images lying on different planes, and possibly perpendicular to a different tooth. The resulting software system (Dental/Vox) has been implemented in C+ + and runs on Intel-based personal computers under the Windows operating systems. DentalVox ensures better mechanical results in the design and planning of a dental implant compared to other, similar software tools; it can reconstruct axial (and panorex and cross-sectional) images once any direction is chosen. This makes it possible to implant a mechanically and esthetically superior prothesis in the underlying gnathic morphology.

[Are urinary tract infections preventable in children? Importance of favorable factors]. / Si possono prevenire le infezioni delle vie urinarie nel bambino? Importanza dei fattori favorenti.

The Authors asked themselves why in the last years they had observed a high increment of urinary tractinfections and so they evidenced some favouring factors.

Is the 13C-acetate breath test a valid procedure to analyse gastric emptying in children?

BACKGROUND/PURPOSE: Scintigraphy is regarded as the "gold standard" procedure in measuring gastric emptying (GE) rates. 13C-acetate breath test (ABT), which already has been validated in adults, is a noninvasive and nonradioactive alternative method. The aim of the current study was to validate ABT against technetium Tc 99m scintigraphy in children affected by delayed GE. METHODS: Sixty children were recruited and divided into 2 groups: group A, 30 healthy controls; group B, 30 patients with gastroesophageal reflux, and scintigraphy-documented DGE (15 neurologically impaired). After an overnight fast, all of them underwent ABT using 25 to 150 mg 13C-acetate. Breath samples were obtained at baseline and then every 10 minutes for 2 hours. The 13CO2 to 12CO2 ratio in breath samples was analysed by isotope ratio mass spectrometry. Data are expressed as follows: time of peak 13C exhalation (tP13CO2b) and half emptying time in ABT (t(1/2b)), and scintigraphy half emptying time (t(1/2s)). RESULTS: In controls tP13CO2b was 37 +/- 13 minutes and t(1/2b) 74 +/- 12 minutes. In patients tP13CO2b and t(1/2b) were, respectively, 65 +/- 26 minutes and 104 +/- 18 minutes t(1/2s) was 91 +/- 21 minutes. In group B tP13CO2b and t(1/2b) were delayed significantly compared with controls, respectively, P < .03 and P < .01. In group B significant correlation between t(1/2s) and t(1/2b) was noted (r1 = 0.97). A close correlation was also observed between t(1/2s) and tP13CO2b (r2 = 0.95). CONCLUSION: The 13C ABT is an easy, reliable, and less expensive procedure for measuring GE, and its results closely correlate with those of scintigraphy in a paediatric population.

[Adolescents and suicide. Some comments on the role of the pediatrician in researching the motivations for suicidal behaviors]. / Adolescenti e suicidio. Alcune considerazioni sul ruolo del pediatra nella ricerca delle motivazioni delle condotte suicidarie.

The modern pediatric is interested also in the adolescent. Sometimes disorders of the behaviour lived of a teenager in a family on risk can lead to attempts of suicide. The authors will analyze at the basis of their experience like pediatrics this problematic.

[The abuse of anabolic substances by an adolescent going in for sports]. / L'abuso di sostanze anabolizzanti nell'adolescente che fa sport.

The authors describe the case of an elder adolescent who showed an imposing symptomatology due to the abuse of anabolic drugs. They urge the pediatricians to warn their patients about the use of such drugs.