Magnetically-coated silica nanospheres for dual-mode imaging at low ultrasound frequency

AIM: To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents(NPCAs) for echographic medical imaging at low ultrasound(US) frequency. METHODS: We synthesized three different nanosized structures:(1) Pure silica nanospheres(SiNSs);(2) FePt-iron oxide(FePt-IO)-coated SiNSs; and(3) IOcoated SiNSs, employing three different diameter of SiNS-core(160, 330 and 660 nm). Tissue mimicking phantoms made of agarose gel solution containing 5 mg of different NPCAs in 2 mL-Eppendorf tubes, were insonified by a commercial echographic system at three different low US pulse values(2.5, 3.5 and 4.5 MHz). The raw radiofrequency signal, backscattered from each considered NPCA containing sample, has been processed in order to calculate the US average backscatter intensity and compare the acoustic behavior of the different NPCA types. RESULTS: The highest US contrast was exhibited by pure SiNSs; FePt-IO-coated SiNSs acoustical behavior followed a similar trend of pure SiNSs with a slight difference in terms of brightness values. The acoustic response of the examined NPCAs resulted function of both SiNS diameter and US frequency. Specifically, higher US frequencies determined higher value of the backscatter for a given SiNS diameter. Frequencydependent enhancement was marked for pure SiNSs and became less remarkable for FePt-IO-coated SiNSs, whereas IO-coated SiNSs resulted almost unaffected by such frequency variations. Pure and FePt-IO-coated SiNSs evidenced an image backscatter increasing with the diameter up to 330 nm. Conversely, among the types of NPCA tested, IO-coated SiNSs showed the lowest acoustical response for each synthesized diameter and employed US frequency, although a diameter-dependent raising trend was evidenced. CONCLUSION: The US characterization of magnetically covered SiNS shows that FePt-IO, rather than IO, was the best magnetic coating for realizing NPCAs suitable for dual mode imaging of deep organs, combining US and magnetic resonance imaging.

Biocompatible Blends Based on Poly(Vinyl Alcohol)and Solid Organic Waste

This work is aimed at the development of new green composite materials through the incorporation of the solid organic waste(SOW)in a thermoplastic matrix.After being ground,the organic waste was exposed to a sterilization process,though an autoclave cycle,in order to obtain a complete removal of the bacterial activity.The SOW was found to have a high amount of water,about 65-70%,which made uneconomical its further treatment to reduce the water amount.Therefore,a water soluble polymer,poly(vinyl alcohol)(PVA)was chosen in order to produce SOW based blends.However,in order to reduce the viscosity of the PVA/SOW slurry,further amount of water was added.The very low viscosity attained by the water suspension allowed to process the PVA/SOW blends by a pressure-free process,for the production of samples,which were afterwards subjected to physical and mechanical characterization.Flexural tests showed the promising properties of the developed blends.In particular,the relevance of porosity was assessed.Increasing the water amount involved a signification increase of porosity,due to a faster water evaporation during processing.On the other hand,compared to neat PVA,addition of SOW allowed to significantly decrease the porosity of the produced samples.Despite this,the mechanical properties of the PVA/SOW blends were shown to be lower than those of neat PVA processed analogously.

Hydroxytryptamine transporter gene-linked polymorphic region(5HTTLPR)is associated with delusions in Alzheimer’s disease

Background:Serotoninergic pathways underlying delusion symptoms in Alzheimer’s disease(AD)have not been fully clarified.5-Hydroxytryptamine transporter gene-linked polymorphic region(5-HTTLPR)is a variable number tandem repeats in the promoter region of serotonin transporter encoding-gene affecting transcription.Methods:We investigated the association of 5-HTTLPR with delusions in a total of 257 consecutive patients clinically diagnosed as AD according to the National Institute on Aging-Alzheimer’s Association criteria.All participants underwent a comprehensive evaluation with a standardized comprehensive geriatric assessment and Neuropsychiatric Inventory.Results:Delusion symptoms were observed in 171 patients(66.54%).In respect to AD patients without delusions,AD patients with delusions showed a low prevalence of S-plus carriers(5-HTTLPR-L/S+5-HTTLPR-S/S genotypes)[p<0.001;odds ratio(OR)=0.240,95% confidence interval(CI)=0.121–0.471].Logistic regression analysis adjusted for the apolipoprotein E polymorphism showed that in AD patients with delusions the presence of an 5-HTTLPR-S allele may reduce disease duration(p=0.005;OR=0.680,95% CI=0.522–0.886)and increase aberrant motor activity(p=0.013;OR=2.257,95% CI=1.195–4.260).The present findings suggested that 5-HTTLPR might be associated with delusions in AD.S-plus carriers might be associated with protective effect against delusions in AD.Conclusions:More studies on wider samples of high selected demented patients are needed to confirm our results.However,the present findings suggested that a genetic factor related to serotonin metabolism might exert a protective role on the clinical expression of neuropsychiatric clusters in AD with important implications regarding mechanisms underlying delusions and their possible treatment across the AD and dementia spectrum.