Near to short wave infrared light generation through AlGaAs-on-insulator nanoantennas

AlGaAs-on-insulator (AlGaAs-OI) has recently emerged as a novel promising platform for nonlinear optics at the nanoscale. Among the most remarkable outcomes, second harmonic generation (SHG) in the visible/near infrared spectral region has been demonstrated in AlGaAs-OI nanoantennas (NA). In order to extend the nonlinear frequency generation towards the short wave infrared window, in this work we propose and demonstrate via numerical simulations difference frequency generation (DFG) in AlGaAs-OI NAs. The NA geometry is finely adjusted in order to obtain simultaneous optical resonances at the pump, signal and idler wavelengths, which results in an efficient DFG with conversion efficiencies up to 0.01%. Our investigation includes the study of the robustness against random variations of the NA geometry that may occur at fabrication stage. Overall, these outcomes identify a new potential and yet unexplored application of AlGaAs-OI NAs as compact devices for the generation and control of the radiation pattern in the near to short infrared spectral region

Whole-exome analysis in osteosarcoma to identify a personalized therapy

Osteosarcoma is the most common pediatric primary non-hematopoietic bone tumor. Survival of these young patients is related to the response to chemotherapy and development of metastases. Despite many advances in cancer research, chemotherapy regimens for osteosarcoma are still based on non-selective cytotoxic drugs. It is essential to investigate new specific molecular therapies for osteosarcoma to increase the survival rate of these patients. We performed exomic sequence analyses of 8 diagnostic biopsies of patients with conventional high grade osteosarcoma to advance our understanding of their genetic underpinnings and to correlate the genetic alteration with the clinical and pathological features of each patient to identify a personalized therapy. We identified 18,275 somatic variations in 8,247 genes and we found three mutated genes in 7/8 (87%) samples (KIF1B, NEB and KMT2C). KMT2C showed the highest number of variations; it is an important component of a histone H3 lysine 4 methyltransferase complex and it is one of the histone modifiers previously implicated in carcinogenesis, never studied in osteosarcoma. Moreover, we found a group of 15 genes that showed variations only in patients that did not respond to therapy and developed metastasis and some of these genes are involved in carcinogenesis and tumor progression in other tumors. These data could offer the opportunity to get a key molecular target to identify possible new strategies for early diagnosis and new therapeutic approaches for osteosarcoma and to provide a tailored treatment for each patient based on their genetic profile

Cardioprotective effects of sodium glucose cotransporter 2 inhibition in angiotensin II-dependent hypertension are mediated by the local reduction of sympathetic activity and inflammation

The cardioprotective effects of sodium glucose cotrasponter 2 (SGLT2) inhibitors seem to be independent from the effects on glycemic control, through little-known mechanisms. In this study, we investigate whether the cardioprotective effects of empagliflozin, a SGLT2 inhibitor, may be associated with myocardial sympathetic activity and inflammatory cell infiltration in an experimental model of angiotensin II-dependent hypertension. Angiotensin II (Ang II), Ang II plus Empagliflozin, physiological saline, or physiological saline plus empagliflozin were administered to Sprague Dawley rats for two weeks. Blood pressure was measured by plethysmographic method. Myocardial hypertrophy and fibrosis were analysed by histomorphometry, and inflammatory cell infiltration and tyrosine hydroxylase expression, implemented as a marker of sympathetic activity, were evaluated by immunohistochemistry. Ang II increased blood pressure, myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase expression, as compared to the control group. Empagliflozin administration prevented the development of myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase overexpression in Ang II-treated rats, without affecting blood glucose and the Ang II-dependent increase in blood pressure. These data demonstrate that the cardioprotective effects of SGLT2 inhibition in Ang II-dependent hypertension may result from the myocardial reduction of sympathetic activity and inflammation and are independent of the modulation of blood pressure and blood glucose levels

Locally advanced leiomyosarcoma of the spleen. A case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Leiomyosarcomas are rare tumours, predominantly localized in the stomach, small intestine and retroperitoneum. Only one case of primary leiomyosarcoma of the spleen is described in human beings in literature.</p> <p>Case presentation</p> <p>We report a case of locally advanced primary leiomyosarcoma of the spleen in a 54 year-old woman, diagnosed only after splenectomy, performed with the suspicion of splenic haematoma.</p> <p>Conclusion</p> <p>Due to the lack of cases, no specific chemotherapy regimen has been tested to provide a longer survival.</p

Variability in genes regulating vitamin D metabolism is associated with vitamin D levels in type 2 diabetes

Mortality rate is increased in type 2 diabetes (T2D). Low vitamin D levels are associated with increased mortality risk in T2D. In the general population, genetic variants affecting vitamin D metabolism (DHCR7 rs12785878, CYP2R1 rs10741657, GC rs4588) have been associated with serum vitamin D. We studied the association of these variants with serum vitamin D in 2163 patients with T2D from the "Sapienza University Mortality and Morbidity Event Rate (SUMMER) study in diabetes". Measurements of serum vitamin D were centralised. Genotypes were obtained by Eco™ Real-Time PCR. Data were adjusted for gender, age, BMI, HbA1c, T2D therapy and sampling season. DHCR7 rs12785878 (p = 1 x 10-4) and GC rs4588 (p = 1 x 10-6) but not CYP2R1 rs10741657 (p = 0.31) were significantly associated with vitamin D levels. One unit of a weighted genotype risk score (GRS) was strongly associated with vitamin D levels (p = 1.1 x 10-11) and insufficiency (&lt;30 ng/ml) (OR, 95%CI = 1.28, 1.16-1.41, p = 1.1 x 10-7). In conclusion, DHCR7 rs12785878 and GC rs4588, but not CYP2R1 rs10741657, are significantly associated with vitamin D levels. When the 3 variants were considered together as GRS, a strong association with vitamin D levels and vitamin D insufficiency was observed, thus providing robust evidence that genes involved in vitamin D metabolism modulate serum vitamin D in T2D

Video-assisted thoracoscopic surgery for postoperative hemothorax

The aim of this study was to evaluate the role of video-assisted thoracoscopic surgery (VATS) in the treatment of postoperative bleeding after thoracic surgery

Switching from magnetic to electric dipole in second harmonic generation from all-dielectric nanoantennas

We report a theoretical model for the study of second harmonic generation in cylindrical structures of finite height. By changing the structure of the pump beam we demonstrate switching from magnetic to electric dipole radiation in the generated second harmonic frequency

Theoretical Model for Pattern Engineering of Harmonic Generation in All-Dielectric Nanoantennas

We develop a novel theoretical model for the study of harmonic generation in cylindrical structures of finite height. Our technique is based on the decomposition of the electromagnetic field over the complete set of modes of the corresponding infinite cylinder. Differently from previous works, in our model no constraints are given neither on the cross section nor on the refractive index of the cylinder. We then apply our approach in the special case of frequency doubling in tall AlGaAs nanodisks, where radiative modes can be neglected. Our results open new perspectives for optimization and engineering of the radiation pattern in harmonic generation processes at the nanoscale

Design of all-dielectric photonic crystals for surface- enhanced Raman scattering

We present the design and optimization of all-dielectric photonic crystal devices for surface-enhanced Raman scattering based application