Carbon nanotubes/polydimethylsiloxanes systems for thermal management of miniaturized electronic components

The thermal performances of nanocomposite layers formed by Single-walled Carbon Nanotubes (SWCNT) dispersed in 2 different kind of polydimethyl-siloxane (PDMSO) matrices has been investigated by measuring the thermal resistance under conditions similar to the ones used for thermal management in microelectronics. A series of nanocomposite samples with thickness in the range 25 microm(-1) cm have been tested. The nanocomposites were prepared varying the amounts of nanotubes embedded in the matrix (from 0.1 to 5%w). In some cases also microsized graphites were mixed to the nanotube's fillers. For 25 micron thick layers, the thermal resistance of the neat silicone specimen can be reduced of 54% with the addition of 2%w carbon nanotubes. The variation of thermal conductivity as a function of the SWCNT's loading is reported and discussed. Furthermore the dispersion's effects of the nanotubes in the layers and the effects on the realization of a net-like system have been investigated.

Synthesis of a novel unsymmetrical Zn(II) phthalocyanine bearing a phenyl ethynyl moiety as sensitizer for dye-sensitized solar cells

A new unsymmetrical zinc phthalocyanine sensitizer has been synthesised. The anchoring of the molecule to nanocrystalline TiO(2) films is realised by a carboxylic group connected to a phenyl ethynyl moiety. Density Functional Theory (DFT) calculations show significant and positive effects of such a functionalization. Electron injection into the semiconductor and photocurrent generation in DSSC are also presented.

Validation of suitable internal control genes for expression studies in aging

Quantitative data from experiments of gene expression are often normalized through levels of housekeeping genes transcription by assuming that expression of these genes is highly uniform. This practice is being questioned as it becomes increasingly clear that the level of housekeeping genes expression may vary considerably in certain biological samples. To date, the validation of reference genes in aging has received little attention and suitable reference genes have not yet been defined. Our aim was to evaluate the expression stability of frequently used reference genes in human peripheral blood mononuclear cells with respect to aging. Using quantitative RT-PCR, we carried out an extensive evaluation of five housekeeping genes, i.e. 18s rRNA, ACTB, GAPDH, HPRT1 and GUSB, for stability of expression in samples from donors in the age range 35-74 years. The consistency in the expression stability was quantified on the basis of the coefficient of variation and two algorithms termed geNorm and NormFinder. Our results indicated GUSB be the most suitable transcript and 18s the least for accurate normalization in PBMCs. We also demonstrated that aging is a confounding factor with respect to stability of 18s, HPRT1 and ACTB expression, which were particularly prone to variability in aged donors.

Managing myelodysplastic symptoms in elderly patients

Most patients with myelodysplastic syndromes (MDS) are elderly (median age range 65 to 70 years); as a consequence, the incidence and prevalence of these diseases are rising as the population ages. Physicians are often uncertain about how to identify patients who may benefit from specific treatment strategies. The International Prognostic Scoring System is a widely used tool to assess the risk of transformation to leukemia and to guide treatment decisions, but it fails to take into account many aspects of treating elderly patients, including comorbid illnesses, secondary causes of MDS, prior therapy for MDS, and other age-related health, functional, cognitive, and social problems that affect the outcome and managing of myelodysplastic symptoms. Patients with low-risk disease traditionally have been given only best supportive care, but evidence is increasing that treatment with novel non-conventional drugs such as lenalidomide or methyltransferase inhibitors may influence the natural history of the disease and should be used in conjunction with supportive-care measures. Supportive care of these patients could also be improved in order to enhance their quality of life and functional performance. Elderly patients commonly have multiple medical problems and use medications to deal with these. In addition, they are more likely to have more than one health care provider. These factors all increase the risk of drug interactions and the consequent treatment of toxicities. Manifestations of common toxicities or illnesses may be more subtle in the elderly, owing to age-associated functional deficits in multiple organ systems. Particularly important to the elderly MDS patient is the age-related decline in normal bone marrow function, including the diminished capacity of response to stressors such as infection or myelosuppressive treatments. Through the integration of geriatric and oncological strategies, a personalized approach toward this unique population may be applied. As with many diseases in the elderly, reliance on family members or friends to maintain the prescribed treatments, including travel to and from appointments, may place additional stressors on the patient and his/her support network. Careful evaluation and knowledge of functional status, ability to tolerate treatments, effect of disease progression, and general overall health conditions can provide the best opportunity to support these patients. Immediate assessment of daily living activities may detect deficiencies or deficits that often require early interventions.

Elevated serum ALT in children presenting to the emergency unit: Relationship with NAFLD

BACKGROUND

Non-alcoholic fatty liver disease, ranging from hepatic steatosis to necro-inflammation with or without fibrosis (non-alcoholic steatohepatitis), is a growing clinical liver disorder in children.

AIM

The goals of this study were to characterize liver disorders associated with elevated aminotransferases and establish the non-alcoholic fatty liver disease/non-alcoholic steatohepatitis prevalence in hypertransaminasemic children admitted to the emergency room.

METHODS

The medical records of 3280 children (2-17 years of age) admitted to the emergency room of Bambino Gesù Children's Hospital of Rome, and presenting with hypertransaminasemia were analysed retrospectively.

RESULTS

Elevation of serum alanine aminotransferases was present in 897 patients. Of these, 520 (58%) spontaneously normalized alanine aminotransferases, and 179/897 (20%) maintained persistently elevated alanine aminotransferases levels. Twenty-one patients were excluded because of medication or alcohol use. In the remaining 157 patients with elevated alanine aminotransferases, obesity was found in 87 (55%), viral infections in 52 (33%) and genetic diseases in 14 (9%). Obesity-related alanine aminotransferases elevation was associated with a histological diagnosis of non-alcoholic fatty liver disease in 85% of patients. In particular, steatosis was histologically confirmed in 74 patients; 43/74 (58%) had steatohepatitis, and 12/74 (16%) had fibrosis.

CONCLUSIONS

Twenty percent of children with elevated aminotransferases on routine testing may hide non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. A careful diagnostic workup of persistent hypertransaminasemia in all obese subjects is warranted in the paediatric setting.

Plasmon polaritons in the near infrared on fluorine doped tin oxide films

Here we investigate plasmon polaritons in fluorine doped tin oxide (FTO) films. By fitting reflectance and transmittance measurements as a function of wavelength lambda epsilon [1.0microm, 2.5microm] we derive a Drude dispersion relation of the free electrons in the transparent conducting oxide films. Then we compute the dispersion curves for the bulk and surface modes together with a reflectance map over an extended wavelength region (lambda==>10microm). Although the surface polariton dispersion for a single FTO/air interface when neglecting damping should appear clearly in the plots in the considered region (since it is supposedly far and isolated from other resonances), a complex behaviour can arise. This is due to different characteristic parameters, such as the presence of a finite extinction coefficient, causing an enlargement and backbending of the feature, and the low film thickness, via coupling between the modes from both the glass/FTO and FTO/air interfaces. Taking into account these effects, computations reveal a general behaviour for thin and absorbing conducting films. They predict a thickness dependent transition region between the bulk polariton and the surface plasmon branches as previously reported for indium tin oxide. Finally, attenuated total reflection measurements vs the incidence angle are performed over single wavelengths lines R(theta) (lambda= 0.633,0.830,1.300,1.550microm) and over a two dimensional domain R(theta,lambda) in the near infrared region lambda epsilon [1.45microm, 1.59microm]. Both of these functions exhibit a feature which is attributed to a bulk polariton and not to a surface plasmon polariton on the basis of comparison with spectrophotometer measurements and modeling. The predicted range for the emergence of a surface plasmon polariton is found to be above lambda >or= 2.1microm, while the optimal film thickness for its observation is estimated to be around 200nm.

Large area interference lithography using a table-top extreme ultraviolet laser: a systematic study of the degree of mutual coherence

A prototype low cost table-top Ar capillary discharge laser source (1.5 ns pulse duration, lambda = 46.9 nm) was successfully used to produce, by means of interference lithography (with a simple Lloyd mirror setup), large area (0.1 mm(2)) regular patterns from 400 nm down to 22.5 nm (half-pitch) on PMMA/Si (PMMA: polymethylmethacrylate) substrates. The experiments allowed a systematical investigation of the degree of mutual coherence of the source, giving a clear indication that the interference lithography can be pushed down to the ultimate resolution limit of lambda/4.

Mapping the intake of different elements in vegetal tissues by dual-energy X-ray imaging at DaPhine synchrotron light source

This article reports on the first utilization of the soft X-ray beamline at the DaPhine synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual-energy X-ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory-controlled samples of vegetal species. The results obtained by the nondestructive X-ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X-ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis.

Interactions between strains of Staphylococcus xylosus and Kocuria varians isolated from fermented meats

AIMS

To evaluate the interactions of Staphylococcus xylosus on Kocuria varians strains isolated from fermented meat products.

METHODS AND RESULTS

Interactions were assessed in vitro by agar spot test, agar well diffusion assay and spectrophotometric assay. The growth of K. varians (five strains) alone was compared with that in the presence of growing cells of S. xylosus (50 strains) or in the presence of heat-treated or untreated supernatants of S. xylosus. Sixteen strains stimulated the growth of K. varians K4, while four strains inhibited the K4 strain. Heated cell-free supernatants of S. xylosus did not have any effect on K. varians. The proteolytic activity of single strains or their combinations was assessed in vitro and in vivo by sodiumdodecylsulfate-polyacrylamide gel electrophoresis of sarcoplasmic protein extracts. Combinations of stimulatory strains of S. xylosus and K. varians showed a higher proteolytic activity compared with that of S. xylosus or K. varians alone.

CONCLUSIONS

The interactions between strains may influence both the growth of the co-cultured strains and proteolysis, technologically relevant characteristics.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study of interactions between coagulase-negative cocci may guide the formulation of mixed strain starters for the production of fermented sausages.

Damage and ablation of large bandgap dielectrics induced by a 46.9 nm laser beam

We applied a 0.3 mJ, 1.7 ns, 46.9 nm soft-x-ray argon laser to ablate the surface of large bandgap dielectrics: CaF2 and LiF crystals. We studied the ablation versus the fluence of the soft-x-ray beam, varying the fluence in the range 0.05-3 J/cm2. Ablation thresholds of 0.06 and 0.1 J/cm2 and ablation depths of 14 and 20 nm were found for CaF2 and LiF, respectively. These results define new ablation conditions for these large bandgap dielectrics that can be of interest for the fine processing of these materials.

Shelf life of fresh sausages stored under modified atmospheres

The aim of this study was to investigate differences in modified atmosphere packaging (MAP) for the improvement of the shelf life of fresh meat products. Three different conditions for preserving fresh sausages were tested: MAP1 (20% CO2, 70% O2, and 10% N2), MAP2 (40% CO2 and 60% O2), and MAP3 (40% CO2, 30% O2, and 30% N2). Samples from the MAP2 group had fewer spoilage bacteria, stable red color (no change of a* value), and good physical attributes (high water-holding capacity, little loss from cooking, and low shear force needed for cutting) compared with samples from other treatment groups. Thus, high concentrations of CO2 (40%) and O2 (60%) resulted in a longer shelf life for fresh sausages.

Prenatal 2-Dimensional and 3-Dimensional Ultrasonography Diagnosis and Autoptic Findings of Isolated Ectopia Cordis

Ectopia cordis is a very rare congenital malformation, commonly associated with intracardiac anomalies. It is due to a defect in fusion of the anterior chest wall resulting in an extrathoracic location of the heart. We report prenatal 2-dimensional (2D) and 3D ultrasonography diagnosis and postnatal autoptic findings of an isolated ectopia cordis with tricuspid atresia. Ectopia cordis prenatal diagnosis is easily made with ultrasound by visualizing the heart outside the thoracic cavity. 3D ultrasonography may add more detailed visualization of the heart anomaly even if the 2D ultrasonography alone permits the prenatal diagnosis. Obstetrical management should include a careful search for associated anomalies, especially cardiac, and the assessment of fetal karyotype. As this is considered a sporadic anomaly, the recurrence risk is low and no genetic origin is known.

Bile salt and acid tolerance ofLactobacillus rhamnosusstrains isolated from Parmigiano Reggiano cheese

This study aimed to compare phenotypic and genetic characteristics of Lactobacillus rhamnosus strains isolated at the end of the ripening of Parmigiano Reggiano cheese and to investigate an important prerequisite of probiotic interest, such as the capability to survive at low pH and in presence of bile salts. The use of API 50 CH, RAPD-PCR analysis and species-specific PCR allowed to ascertain the identity of 63 L. rhamnosus strains. Three L. rhamnosus strains isolated from Parmigiano Reggiano cheese, L. rhamnosus ATCC 7469T and the commercial strain L. GG were assayed to estimate the resistance to various stress factors reproducing in vitro some conditions of the gastro-intestinal environment such as low pH and different amounts of bile salts and acids. The behaviour of almost all the tested strains isolated from Parmigiano Reggiano cheese resulted analogous to that showed by L. GG.

Prenatal and postnatal findings of acrania

INTRODUCTION

Acrania is a rare congenital anomaly in which the flat bones of the cranial vault are partial or complete absent with complete but abnormal development of the cerebral hemispheres.

CASE REPORT

We report two cases, diagnosed prenatally by ultrasound and followed by medical pregnancy termination, one with isolated acrania and one with associated cleft lip and palate and spina bifida.

DISCUSSION

The acrania pathogenesis is unknown and differential diagnosis should be made with other conditions like anencephaly and acalvaria. Genetic counselling is not easy because there is no evidence for a specific genetic origin, but the extreme rarity and sporadic nature suggests a low recurrence risk.