Broadband amplified spontaneous emission and random lasing from wurtzite CdSe/CdS 'giant-shell' nanocrystals

Colloidal nanocrystals (NCs) are attractive materials for light-emitting applications thanks to their flexible synthesis, size-dependent properties, and bright emission. Yet, colloidal NCs still present a narrow gain band (full-width half maximum around 10 nm), which limits their application to single-color lasers. Widening of the gain band by specifically engineered NCs can further improve the prospect of this class of materials toward the fabrication of solution-processed white-emitting or color-tunable lasers. Here, we report broadband amplified spontaneous emission (ASE) from wurtzite CdSe/CdS "giant-shell" nanocrystals (g-NCs) with an unprecedented large core up to 7.5 nm in diameter that were synthesized through a continuous injection route. The combination of large core and shell enables ASE from different CdSe optical transitions as well as from the CdS. Importantly, thin films of g-NCs with a large CdSe core (7.5 and 5.1 nm in diameter) show ASE at different colors with a similar threshold, indicating that light emission amplification can be achieved from different optical transitions simultaneously. Tuning of the core diameter allows obtaining ASE in a wide spectral range, and blending of g-NCs with different core sizes gives rise to a continuous amplified spontaneous emission band from green to red (510 to 650 nm). Drop-cast films of CdSe/CdS g-NCs demonstrate simultaneous dual-color random lasing under nanosecond-pulsed excitation

Near-infrared emitting colloidal PbS nanoplatelets : lateral size control and optical spectroscopy

Two dimensional (2D) colloidal PbS nano platelets (NPLs) with a thickness of 1.8-2.8 nm have been synthesized using a single-molecule precursor approach with lead octadecylxanthate. The lateral dimensions were tuned by varying the reaction temperature, growth time, and capping ligands. Transmission electron microscopy and X-ray diffraction reveal that the NPLs have an orthorhombic crystal structure rather than the rocksalt phase usually reported for bulk and nanostructured PbS. The 1.8 nm thickness, in combination with the tunable lateral dimensions, results in a blue-shifted absorption peak at 71S-730 nm and a 48-68 nm narrow emission spectrum with a surprisingly small, 18 nm Stokes shift at room temperature. The fluorescence lifetime of these PbS NPLs is 2 orders of magnitude shorter than the typical lifetime in OD colloidal PbS quantum dots, highlighting the advantageous properties of colloidal 2D nanostructures that combine strong transversal with weak lateral confinement

Protective Effect of Wheat Derived Non-specific lipid-transfer Protein 2 on Vascular Endothelium Inflammation

The important functions of the endothelium and the relationship between cardiovascular risk factors and endothelial dysfunction suggest the primary role of this tissue as a target for dietary strategies aimed at the prevention from related diseases. Cereals are key component of a healthy and balanced diet, and the presence of non-specific lipid-transfer protein 2 (nsLTP2) in wheat represents an added value to contribute to maintain the functionality of the vascular endothelium and consequently of the cardiovascular system. Indeed, nsLTP2 downregulates the expression of the main cell adhesion molecules induced by a pro-inflammatory cytokine and, meanwhile, upregulates heme oxigenase-1, exerting a cytoprotective/anti-inflammatory activity. Therefore, nsLTP2 might represent a food-derived tool to protect the vascular system against several pathological condition

Hepatitis E Virus in Pork Production Chain in Czech Republic, Italy, and Spain, 2010

open11siWe evaluated the prevalence of hepatitis E virus (HEV) in the pork production chain in Czech Republic, Italy, and Spain during 2010. A total of 337 fecal, liver, and meat samples from animals at slaughterhouses were tested for HEV by real-time quantitative PCR. Overall, HEV was higher in Italy (53%) and Spain (39%) than in Czech Republic (7.5%). HEV was detected most frequently in feces in Italy (41%) and Spain (39%) and in liver (5%) and meat (2.5%) in Czech Republic. Of 313 sausages sampled at processing and point of sale, HEV was detected only in Spain (6%). HEV sequencing confi rmed only g3 HEV strains. Indicator virus (porcine adenovirus) was ubiquitous in fecal samples and absent in liver samples and was detected in 1 slaughterhouse meat sample. At point of sale, we found porcine adenovirus in sausages (1%–2%). The possible dissemination of HEV and other fecal viruses through pork production demands containment measures.openI. Di Bartolo; M. Diez-Valcarce; P. Vasickova; P. Kralik; M. Hernandez; G. Angeloni; F. Ostanello; M. Bouwknegt; D. Rodríguez-Lázaro; I. Pavlik; F. M. RuggeriI. Di Bartolo; M. Diez-Valcarce; P. Vasickova; P. Kralik; M. Hernandez; G. Angeloni; F. Ostanello; M. Bouwknegt; D. Rodríguez-Lázaro; I. Pavlik; F. M. Rugger

Melatonin MT1 receptors as a target for the psychopharmacology of bipolar disorder: a translational study

The treatment of bipolar disorder (BD) still remains a challenge. Melatonin (MLT), acting through its two receptors MT1 and MT2, plays a key role in regulating circadian rhythms which are dysfunctional in BD. Using a translational approach, we examined the implication and potential of MT1 receptors in the pathophysiology and psychopharmacology of BD. We employed a murine model of the manic phase of BD (Clock mutant (ClockΔ19) mice) to study the activation of MT1 receptors by UCM871, a selective partial agonist, in behavioral pharmacology tests and in-vivo electrophysiology. We then performed a high-resolution Nuclear Magnetic Resonance study on isolated membranes to characterize the molecular mechanism of interaction of UCM871. Finally, in a cohort of BD patients, we investigated the link between clinical measures of BD and genetic variants located in the MT1 receptor and CLOCK genes. We demonstrated that: 1) UCM871 can revert behavioral and electrophysiological abnormalities of ClockΔ19 mice; 2) UCM871 promotes the activation state of MT1 receptors; 3) there is a significant association between the number of severe manic episodes and MLT levels, depending on the genetic configuration of the MT1 rs2165666 variant. Overall, this work lends support to the potentiality of MT1 receptors as target for the treatment of BD

Detection of Hepatitis E virus in swine liver sausage, in Italy

Hepatitis E is a viral disease usually self limiting with low mortality, but it can become chronic in transplanted patients and be highly lethal during pregnancy. Hepatitis E virus (HEV) is a small RNA virus, which infects humans and several animal species. Four mammalian HEV genotypes are known, among which g3 and g4 are considered zoonotic. In Italy, g3 strains have been detected in swine farms and slaughterhouses, and were associated to human cases. Recently, swine HEV was detected in the pork food chain in four European countries.We have investigated the presence of HEV in liver sausage, which is often consumed uncooked in Italy, France, and other countries. In 2012, four packs (300 gr) of pork liver sausage were bought at a butcher bench, at 2 different times. Forty five portions (200 mg) were contaminated artificially with murine norovirus (MNV). After RNA extraction, samples were analyzed for detection of HEV, MNV (process control), and porcine adenovirus (pAdV, index virus of fecal contamination). HEV was evaluated by RT PCR, targeting several genomic regions. Altogether, 2 samples (4.4%) resulted positive for HEV in at least one PCR. Sequence analysis confirmed swine g3 HEV in both samples. PAdV was detected only once, in a HEV positive sample. Attempts to infect A549 cells with a HEV positive liver extract were repeatedly unsuccessful. This study confirms that pig liver sausage may contain HEV, possibly resulting from fecal contamination during improper slaughtering. Further studies to investigate residual HEV infectivity in pork, and consumer\u2019s risks are needed

Complete genome sequencing of a genotype 3 hepatitis E virus strain identified in a swine farm in Italy

In this study, we investigated hepatitis E virus (HEV) infection in piglets sampled in two farms in southern Italy. The virus was detected in 11 out of 15 animals tested. Based on sequence analysis, the 6 Italian strains examined belonged to two clusters containing both swine and human strains of either genotype 3 subtype e or f from Europe and Japan. The two Italian strain clusters shared nucleotide identity of 81.8% and 87.5% in the ORF2 (capsid protein) and ORF1 (RdRp) diagnostic fragments, respectively, confirming the heterogeneity of genotype 3 viruses circulating in pigs in Italy. The complete genome of one genotype 3 subtype e strain and the full ORF2 and ORF3 coding regions of one of the genotype 3f strains, obtained in this study, were compared to other HEV sequences available on line (NCBI database). The results of analysis showed that porcine strains clustered together with human and swine strains detected in Europe. Most changes in the coding region corresponded to synonymous mutations, and only the ORF3 showed a positive selection. Further analyses are needed to understand the clinical significance of HEV genotypes and subtypes

Synthesis of anisotropic CdSe/CdS dot-in-giant-rod nanocrystals with persistent blue-shifted biexciton emission

Anisotropic single-phase wurtzite CdSe/CdS nanocrystals were synthesized by colloidal chemistry, introducing ZnCl2 to increase the shell growth in the radial direction. As a result, dot-in-giant-rod nanocrystals were obtained, with a core diameter that varied between 3.2 and 7.5 nm and an overall diameter between 15 and 22 nm, corresponding to a 14-26 ML CdS shell. In addition to an extended fluorescence lifetime, typical for CdSe/CdS heteronanocrystals, all samples also yielded a blue-shifted biexciton emission peak. This contrasts with existing data on CdSe/CdS dot-in-rod nanocrystals with a thin shell, which yield a type-I band offset and attractive biexciton interactions for CdSe/CdS with a core larger than about 2.8 nm. However, k.p calculations support the blue shift, with a significant electron delocalization into the CdS shell even for large core diameter. We assign this effect to the influence of strain at the CdSe/CdS interface and associated reduction of the conduction band offset, as well as the buildup of a piezoelectric field along the nanorod long axis. The strain-induced electron hole separation is particularly effective in large-core nanocrystals, providing a tool to engineer electron and hole wave functions that is complementary to quantum confinement

Peripheral Inflammatory Markers and Antioxidant Response during the Post-Acute and Chronic Phase after Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is a mechanical insult to the brain caused by external forces and associated with inflammation and oxidative stress. The patients may show different profiles of neurological recovery and a combination of oxidative damage and inflammatory processes can affect their courses. It is known that an overexpression of cytokines can be seen in peripheral blood in the early hours/days after the injury, but little is known about the weeks and months encompassing the post-acute and chronic phases. In addition, no information is available about the antioxidant responses mediated by the major enzymes that regulate reactive oxygen species levels: superoxide dismutase, catalase, peroxidases, and GSH-related enzymes. This study investigates the 6-month trends of inflammatory markers and antioxidant responses in 22 severe TBI patients with prolonged disorders of consciousness, consecutively recruited in a dedicated neurorehabilitation facility. Patients with a high degree of neurological impairment often show an uncertain outcome. In addition, the profiles of plasma activities were related to the neurological recovery after 12 months. Venous peripheral blood samples were taken blindly as soon as clinical signs and laboratory markers confirmed the absence of infections, 3 and 6 months later. The clinical and neuropsychological assessment continued up to 12 months. Nineteen patients completed the follow-up. In the chronic phase, persistent high plasma levels of cytokines can interfere with cognitive functioning and higher post-acute levels of cytokines [interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL1b, IL6] are associated with poorer cognitive recoveries 12 months later. Moreover, higher IFN-γ, higher TNF-α, and lower glutathione peroxidase activity are associated with greater disability. The results add evidence of persistent inflammatory response, provide information about long-term imbalance of antioxidant activity, and suggest that the over-production of cytokines and the alteration of the redox homeostasis in the post-acute phase might adversely affect the neurological and functional recovery. Inflammatory and antioxidant activity markers might offer a feasible way to highlight some of the processes opposing recovery after a severe TBI