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.

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.

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.

Diagnostic value of objective campimetry.

The results obtained in ten normal subjects with a new method of pupillocampimetry are described and compared with those obtained with routine campimetry. Once the relationship between the two methods was established, ten subjects suffering from pregeniculate or postgeniculate lesions of the optic pathways were examined by pupillocampimetry. This study shows the value of this new method, particularly for the differential diagnosis of pre- or postgeniculate lesions.

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.

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.

[The technique of pediatric examination of an adolescent with personality problems]. / La tecnica della visita pediatrica all'adolescente con problemi del carattere.

The authors suggest the behaviour which the pediatrician has to keep with the adolescent and his family. The authors believe that in the "puberal spurt" period the pediatrician must inform the parents about the mould change which the young will inevitably have.

[Host-microorganism interactions in urinary infections in children]. / Interazioni ospite-germe nelle infezioni urinarie del bambino.

The authors examine the factors which induce urinary tract infections (U.T.I.) in child, considering especially the mechanisms which operate in the microorganism-host relation. Besides, the last acquisitions about clinical pediatric urology are specified. The Author dwells upon the discovery and study of P-fimbriated Escherichia coli, which seems ascertained to be responsible of upper urinary tract infections and which can be identified in Laboratories thanks to the existence of kits prepared for this purpose. With reference to this subject, the Authors report a personal experience about 12 pediatric patients in whose urine P-fimbriated E.coli strains were identified; in these patients the correlation is studied between the presence of P-fimbriated E.coli and the severity of infection (pyelonephritis, recurrent U.T.I.).

[The pediatrician and the child with a psychosomatic disease: some reflections]. / Il pediatra ed il bambino con malattia psicosomatica: alcune riflessioni.

Not very carefully taking into account a possible psychosomatic pathology in children can, in many occasions, cause the pediatrician to make seriously wrong diagnostic, prognostic and therapeutic evaluations. As this is valid at any age, the authors affirm that particularly at the evolutive age, and since the first months of life, many circumstances occur in which the functional trouble can sometimes a serious organic pathology.

[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.

[The microbiological exam of the urine: what significance in urinary tract infections?]. / Esame microbiologico delle urine: quale significato nelle infezioni delle vie urinarie?

11,829 urine cultures, coming from the Pediatrics Department of Florence and other hospital divisions for adults in the period 1st of July-31st of December 1990, have been examined in the Bacteriology and Virology Laboratory of the University Hospital of Florence. Besides illustrating various methods of drawing, preservation and transport of the urinary specimen, the authors showed the incidence of bacterial species responsible of urinary tract infections (U.T.I.). E. coli was showed to be the most frequently isolated bacterial strain, followed by Streptococcus faecalis and Proteus indole negative. The incidence of fimbriated E. coli infections was studied in pediatric and adult patients with urinary tract infections; a higher isolation frequency of fimbriated E. coli was showed in pediatric patients and in these patients the correlation was studied between the presence of fimbriated E. coli and the severity of infection (pyelonephritis, recurrent U.T.I.). The percentages of resistance of the isolated strains against the most common chemotherapies was also showed, studying their variations, for some chemotherapies, during about twenty years.

[The new parents. The importance of the pediatrician-child-parent triad]. / I nuovi genitori. Importanza della triade pediatra-bambino-famiglia.

During these past years pediatricians have been more and more interested to the adolescent's matters. Undoubtedly adolescent's behavioural disturbances are to be bound to a childhood spent in a wrong way, and contemporarily managed by parents who, despite their maximum dedication, have not "trained" their children according to specific "fundamentals", probably because also they themselves, when children, have not been submitted to them.

[Recurrent cystitis in children: do predisposing factors exist for its onset?]. / Le cistiti recidivanti nel bambino: esistono cause che favoriscono la loro insorgenza?

It is known that a great number of subjects, mainly little girls, frequently go to pediatric's observation for recurrent episodes of pollakiuria, dysuria or burning miction. They often complain enuresis, sometimes tenesmus so intense that they arrive at the incontinence (urge incontinence). Many of these cases, quickly defined as cystitis, really revealed that they weren't. Repetitively negative bacteriologic examinations allow us to classify them as "sham syndromes", as Stephens called them. According to what we said above, we wondered whether any recurrent cystitis are not favoured by missed observation of definite rules.

[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.

[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!

[Leukorrhea in adolescents: an underestimated problem]. / Le leucorree nell'adolescente: un problema sottostimato.

It is by now clear that pediatrician's interest about adolescent's matters is very much increasing. The Authors take into consideration vulvovaginitis, a particular matter which is very frequent during this period of life and describe its most important clinical aspects.

[The emotional rapport between mother and child during the first months of life]. / Rapporto emozionale tra la madre e il bambino nei primi mesi di vita.

Feeding children involves a mutual interaction between their parents and them; interaction in which everyone is influenced by and, contemporarily, influences the others. In fact the act of administering food is considered to be fundamental inside the relationship between the mother and her child. Such a relationship can supply consequences that are important for the children's physical, emotional and cognitive growth, particularly in their first two years of life. Therefore, any time a child arrives at the pediatrician's attention showing a nourishment matter, and anamnesis and examination are indicative of a lack of evidence that may address to a physical disease, the next zone to be indagated must be the existing relationship between the child and his family.

[Urinary tract infections in childhood: importance of immediate urine culture. Personal experience with 4176 tests]. / Le infezioni delle vie urinarie in età pediatrica: importanza dell'immediato esame colturale delle urine. Esperienza personale su 4176 esami.

Since infections of the urinary tract in children often present diagnostic difficulties, it is essential to be able to identify these patients with simple, reliable methods. After a clinical-laboratory study on 4176 urine cultures, the Authors affirm that the reliability of this test is much greater when the parents have been instructed in the correct way of collection the urine specimen, and when in the laboratory the "slide" is carried out within three hours of taking the sample.

[Hematuria due to an unusual cause in an adolescent]. / Ematuria da causa insolita in un adolescente.

The authors describe a case of haematuria due to the von Willebrand disease. The purpose of this article is to stimulate the performing of coagulation tests in patients with a pre-renal haematuria.

[Middle lobe syndrome in children. Critical review]. / La sindrome del lobo medio nel bambino. Rivisitazione critica.

The clinical, radiological and anatomo-evolutive pictures of this syndrome are typical. It is suggested that cases are more frequent than is generally thought and that their recognition is delayed on account of the considerable time that often elapses before repeated infection of the respiratory system, particularly the middle lobe, results in the onset of the syndrome.