Phase-Insensitive Scattering of Terahertz Radiation

The nonlinear interaction between Near-Infrared (NIR) and Terahertz pulses is principally investigated as a means for the detection of radiation in the hardly accessible THz spectral region. Most studies have targeted second-order nonlinear processes, given their higher efficiencies, and only a limited number have addressed third-order nonlinear interactions, mainly investigating four-wave mixing in air for broadband THz detection. We have studied the nonlinear interaction between THz and NIR pulses in solid-state media (specifically diamond), and we show how the former can be frequency-shifted up to UV frequencies by the scattering from the nonlinear polarisation induced by the latter. Such UV emission differs from the well-known electric-field-induced second harmonic (EFISH) one, as it is generated via a phase-insensitive scattering, rather than a sum- or difference-frequency four-wave-mixing process

Synthesis, Conformation and Antiproliferative Activity of Isothiazoloisoxazole 1,1-dioxides

Sixteen new isothiazoloisoxazole 1,1-dioxides, one new isothiazolotriazole and one new isothiazolopyrazole have been synthesised by using 1,3-dipolar cycloadditions to isothiazole 1,1-dioxides. One sub-set of these isothiazoloisoxazoles showed low μM activity against a human breast carcinoma cell line, whilst a second sub-set plus the isothiazolotriazole demonstrated an interesting restricted rotation of sterically hindered bridgehead substituents. A thiazete 1,1-dioxide produced from one of the isothiazole 1,1-dioxides underwent conversion into an unknown 1,2,3-oxathiazolin-2-oxide upon treatment with Lewis acids, but was inert towards 1,3-dipoles and cyclopropenones. Six supporting crystal structures are included

Circulatory miR-223-3p Discriminates Between Parkinson’s and Alzheimer’s Patients

MiR-223-3p is involved in the regulation of a broad range of cellular processes and in many types of pathological processes as cancer, autoimmune and inflammatory diseases. MiR-223-3p has been indicated as negative regulator of NLRP3 protein, a key protein of inflammasome. The chronic inflammasome activation, an underlying feature of neurodegenerative disorders, is induced by misfolded protein aggregates, including amyloid-beta and alpha-synuclein, resulting in pro-inflammatory cytokines secretion and propagating of neuroinflammation. The aim of the study was to analyze whether circulatory miR-223-3p could be used as biomarker in neurodegeneration and to clarify its possible relationship with inflammasome activation. miR-223-3p concentration was evaluated in serum of Alzheimer\u2019s (AD) and Parkinson\u2019s disease (PD) or mild cognitive impairment (MCI) patients and healthy controls (HC). Compared to HC, miR-223-3p serum concentration was reduced in MCI and AD, but up-regulated in PD (p < 0.0001), and it decreased progressively from MCI to moderate (p < 0.0001) to severe AD (p = 0.0016). Receiver operating characteristic analysis showed that miR-223-3p concentration discriminates between AD, PD and MCI vs. HC, as well as between AD and PD. miR-223-3p serum concentration discriminates between AD/MCI and PD, suggesting that this molecule could be a potential non-invasive biomarker for differential diagnosis and prognosis of these neurodegenerative conditions

Predictive Values of Transcutaneous Oxygen Tension for Above-the-ankle Amputation in Diabetic Patients with Critical Limb Ischemia

ObjectiveTo assess the values of transcutaneous oxygen tension (TcPO2) capable of predicting above-the-ankle amputation in diabetic patients diagnosed for critical limb ischemia (CLI) according to the criteria of the TransAtlantic Inter-Society Consensus.DesignRetrospective study.MethodsFrom January 1999 to December 2003, 564 diabetic patients were consecutively hospitalized for CLI in one limb. Revascularization with angioplasty or bypass graft was performed when possible and, if not possible, prostanoid therapy was used. In patients in whom therapies did not relieve the rest pain or the gangrene was extended above the Chopart joint, an above-the-ankle-amputation was performed. After treatment TcPO2 values were evaluated in all patients at the dorsum of the foot.ResultsFifty-five (9.8%) patients underwent an above-the-ankle amputation: 22 of 420 patients who underwent angioplasty, 17 of 117 patients who underwent bypass (14.5%) and 16 of 27 patients in whom revascularization was not possible. Post-treatment TcPO2, measured by a receiver operating characteristic (ROC) curve, showed a value 34mmHg as the best threshold for determining the need for revascularization, with an area under the curve of 0.89 (95%CI 0.85–0.94).Using logistic regression analysis the probability of above-the-ankle amputation for this threshold is 9.7% and reduces to 3% for TcPO2>40mmHg.ConclusionTcPO2 levels<34mmHg indicate the need for revascularization, while for values ≥ 34<40mmHg this need appears less pressing, although there remains a considerable probability of amputation. TcPO2 levels greater than 40mmHg suggest that revascularization is dependent on the severity of tissue loss and possible morbidity caused by the procedure

Emergence of X-shaped spatiotemporal coherence in optical waves

Considering the problem of parametric nonlinear interaction, we report the experimental observation of electromagnetic waves characterized by an X-shaped spatiotemporal coherence; i.e., coherence is neither spatial nor temporal, but skewed along specific spatiotemporal trajectories. The application of the usual, purely spatial or temporal, measures of coherence would erroneously lead to the conclusion that the field is fully incoherent. Such hidden coherence has been identified owing to an innovative diagnostic technique based on simultaneous analysis of both the spatial and temporal spectra

X-shaped space-time coherence in optical parametric generation

We study the spatiotemporal coherence properties of superfluorescence radiation generated in optical parametric amplification of quantum noise. We show that the angular dispersion properties of the spatiotemporal spectra, measured in different phase-matching conditions, lead to a clear X-shaped structure of the mutual correlation function of the radiation. Within a statistical picture, we interpret the generated superfluorescence as a stochastic \u201cgas\u201d of quasistationary modes characterized by a skewed correlation in the spatiotemporal domain, with characteristics similar to linear and nonlinear X waves not describable within a separable approach in space and time

Laser-assisted guiding of electric discharges around objects

Electric breakdown in air occurs for electric fields exceeding 34 kV/cm and results in a large current surge that propagates along unpredictable trajectories. Guiding such currents across specific paths in a controllable manner could allow protection against lightning strikes and high-voltage capacitor discharges. Such capabilities can be used for delivering charge to specific targets, for electronic jamming, or for applications associated with electric welding and machining. We show that judiciously shaped laser radiation can be effectively used to manipulate the discharge along a complex path and to produce electric discharges that unfold along a predefined trajectory. Remarkably, such laser-induced arcing can even circumvent an object that completely occludes the line of sight