The geometrical nature of optical resonances : from a sphere to fused dimer nanoparticles

We study the electromagnetic response of smooth gold nanoparticles with shapes varying from a single sphere to two ellipsoids joined smoothly at their vertices. We show that the plasmonic resonance visible in the extinction and absorption cross sections shifts to longer wavelengths and eventually disappears as the mid-plane waist of the composite particle becomes narrower. This process corresponds to an increase of the numbers of internal and scattering modes that are mainly confined to the surface and coupled to the incident field. These modes strongly affect the near field, and therefore are of great importance in surface spectroscopy, but are almost undetectable in the far field

Behavioral and psychological effects of coronavirus disease-19 quarantine in patients with dementia

Background: In March 2020, the World Health Organization declared a global pandemic due to the novel coronavirus SARS-CoV-2 and several governments planned a national quarantine in order to control the virus spread. Acute psychological effects of quarantine in frail elderly subjects with special needs, such as patients with dementia, have been poorly investigated. The aim of this study was to assess modifications of neuropsychiatric symptoms during quarantine in patients with dementia and their caregivers. Methods: This is a sub-study of a multicenter nation-wide survey. A structured telephone interview was delivered to family caregivers of patients with diagnosis of Alzheimer disease (AD), dementia with Lewy bodies (DLB), frontotemporal dementia (FTD), and vascular dementia (VD), followed regularly at 87 Italian memory clinics. Variations in behavioral and psychological symptoms (BPSD) were collected after 1 month since quarantine declaration and associations with disease type, severity, gender, and caregiver\u2019s stress burden were analyzed. Results: A total of 4,913 caregivers participated in the survey. Increased BPSD was reported in 59.6% of patients as worsening of preexisting symptoms (51.9%) or as new onset (26%), and requested drug modifications in 27.6% of these cases. Irritability, apathy, agitation, and anxiety were the most frequently reported worsening symptoms and sleep disorder and irritability the most frequent new symptoms. Profile of BPSD varied according to dementia type, disease severity, and patients\u2019 gender. Anxiety and depression were associated with a diagnosis of AD (OR 1.35, CI: 1.12\u20131.62), mild to moderate disease severity and female gender. DLB was significantly associated with a higher risk of worsening hallucinations (OR 5.29, CI 3.66\u20137.64) and sleep disorder (OR 1.69, CI 1.25\u20132.29), FTD with wandering (OR 1.62, CI 1.12\u20132.35), and change of appetite (OR 1.52, CI 1.03\u20132.25). Stress-related symptoms were experienced by two-thirds of caregivers and were associated with increased patients\u2019 neuropsychiatric burden (p<0.0001). Conclusion: Quarantine induces a rapid increase of BPSD in approximately 60% of patients and stress-related symptoms in two-thirds of caregivers. Health services need to plan a post-pandemic strategy in order to address these emerging needs

"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Development of a methodology for evaluating investments in infrastructure for the sustainable exploitation of shale energy in Argentina

Thesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.Cataloged from PDF version of thesis.Includes bibliographical references (pages 153-157).In 2011, a new word entered into the popular vocabulary of Argentina: Vaca Muerta (VM, literally: Dead Cow); almost like a discovery, it was announced that Argentina had large hydrocarbon resources that were trapped in underground shale and tight rocks. In reality, these resources were known by geologists from the beginning of the oil industry, but only became economically extractable in the 2000s, with the use of two old technologies developed in the US and already used on conventional fields: hydraulic fracturing and horizontal drilling. With this "discovery," the Argentine energy perspective changed radically: a sector that was declining became dynamic again and became a target for investment for a project that for many Argentines was still just a name. By 2014, around three billion dollars has been invested in VM almost exclusively by the oil & gas sector, led by the national oil company (YPF), but there were very few analyses on how VM would affect other sectors, like the logistics and transportation system. By the intrinsic technical characteristics of these two essential technologies, the amount of inputs required in the wellheads is extremely high (especially in comparison with conventional exploitations), producing a strong demand for transportation and logistics services. This high volume of transportation services requires infrastructure capacity, meaning large long-term investments. Following this, a key question arises: who should pay for new capacity of public infrastructure that will be used by a few actors in a private business (oil and gas) that is profitable? Should it be the public sector through the use of tax-revenues or should it be the private sector that must pay with its own savings generated by using more efficient transport modes? Seeking to answer these questions, this thesis developed and implemented a Simultaneous Economic-Financial Analysis Model (SEFAM) to evaluate the private and public incentives that will finally determine investment alternatives to achieve socially optimal solutions. The CLIOS Process, for studying complex sociotechnical systems, is used to study the relationships between the shale oil production system and the logistic and transportation system, with the institutional actors that govern them. The East-West VM supply corridor was selected as the research case of this thesis, in order to implement SEFAM and draw some general conclusions. This research describes this interaction between shale energy production and its logistic and transportation requirements, along with the proposition of certain questions that advance a better understanding of the problem. SEFAM is then seen as an integrative tool that allows the decision-maker to have useful and relevant information for a prospective negotiation process between the public and private sectors, looking to ensure the implementation of the socially optimal alternative.by Bruno R. Agosta.S.M

TERATOMI SACRO-COCCIGEI: Osservazioni su 25 casi

Gli Autori presentano i dati relativi ad uno studio retrospettivo su 25 casi di Teratoma sacrococcigeo, osservati tra il 1980 ed il 1988

UNA RARA INDICAZIONE ALLA LOBECTOMIA DEL NEONATO: L'Emangioendotelioma complicato

L'Emangioendotelioma epatico (EEE) è un raro tumore benigno vascolare dell'età pediatrica di maggiore riscontro nella prima infanzia, periodo durante il quale può essere causa di notevoile morbilità e mortalità per le temibili complicanze possibili. Gli Autori presentano un caso di EEE nel neonato, occorso alla loro osservazione e discutono le problematiche relative alla diagnosi ed al trattament

LA SINDROME DI PRUNE-BELLY: Considerazioni cliniche e terapeutiche

La Sindrome di Prune-Belly si può manifestare con una ampia varietà di quadri clinici,a prognosi variabile anche in rapporto al grado di compromissione renale. Gli Autori presentano uno studio retrospettivo su 6 casi osservati dal 1980 al 1991 e discutono l'importanza di un corretto inquadramento diagnostico e terapeutic