Exploring the multiparameter nature of EUV-visible wave mixing at the FERMI FEL.

The rapid development of extreme ultraviolet (EUV) and x-ray ultrafast coherent light sources such as free electron lasers (FELs) has triggered the extension of wave-mixing techniques to short wavelengths. This class of experiments, based on the interaction of matter with multiple light pulses through the Nth order susceptibility, holds the promise of combining intrinsic ultrafast time resolution and background-free signal detection with nanometer spatial resolution and chemical specificity. A successful approach in this direction has been the combination of the unique characteristics of the seeded FEL FERMI with dedicated four-wave-mixing (FWM) setups, which leads to the demonstration of EUV-based transient grating (TG) spectroscopy. In this perspective paper, we discuss how the TG approach can be extended toward more general FWM spectroscopies by exploring the intrinsic multiparameter nature of nonlinear processes, which derives from the ability of controlling the properties of each field independently.

Polarization-state-resolved high-harmonic spectroscopy of solids.

Attosecond metrology sensitive to sub-optical-cycle electronic and structural dynamics is opening up new avenues for ultrafast spectroscopy of condensed matter. Using intense lightwaves to precisely control the fast carrier dynamics in crystals holds great promise for next-generation petahertz electronics and devices. The carrier dynamics can produce high-order harmonics of the driving field extending up into the extreme-ultraviolet region. Here, we introduce polarization-state-resolved high-harmonic spectroscopy of solids, which provides deeper insights into both electronic and structural sub-cycle dynamics. Performing high-harmonic generation measurements from silicon and quartz, we demonstrate that the polarization states of the harmonics are not only determined by crystal symmetries, but can be dynamically controlled, as a consequence of the intertwined interband and intraband electronic dynamics. We exploit this symmetry-dynamics duality to efficiently generate coherent circularly polarized harmonics from elliptically polarized pulses. Our experimental results are supported by ab-initio simulations, providing evidence for the microscopic origin of the phenomenon.

Prognostic value of subclassification of T2 tumours in patients with gastric cancer.

BACKGROUND: This study was designed to evaluate the prognostic value of tumour stage T2 subcategorization (T2a and T2b) in patients with gastric carcinoma. METHODS: Clinicopathological details of a prospective series of patients who had radical resection of gastric adenocarcinoma in a single institution were analysed. Univariable and multivariable survival analyses were performed with the log rank test and Cox's model respectively. RESULTS: Of 373 evaluable patients, 49 (13.1 per cent) had a T2a and 143 (38.3 per cent) a T2b tumour. At a median follow-up of 35.5 months, the 5-year overall survival rate was 73 and 31.1 per cent for patients with T2a and T2b lesions respectively (P < 0.001). On multivariable analysis, T stage remained an independent prognostic factor. Compared with T1a, the mortality risk for patients with T1b (hazard ratio (HR) 1.00; P = 0.992) and T2a (HR 0.97; P = 0.916) tumours was similar; by contrast, the risk of death associated with T2b (HR 1.81; P = 0.031) and T3 (HR 1.89; P = 0.038) lesions was significantly greater than for T1a tumours. CONCLUSION: Subclassification of T2 tumours should be undertaken routinely in order to stratify patients with gastric cancer more accurately in terms of their mortality risk.

A case of breast angiosarcoma: diagnostic imaging and review of the literature.

Primary angiosarcoma of the breast is a rare tumor, with approximately 170 cases reported in the literature (1-3, 10, 11, 15). Reports on the imaging characteristics of these tumors have been occasional until a recent review by Liberman et al. (11). Diagnostic imaging of the masses include mammographic and ultrasound examinations (5): the imaging characteristics of the tumor can be nonspecific and sometimes heterogeneous (11). Only recently was one case evaluated with magnetic resonance imaging (11). We present the mammographic and sonographic features of a case of primary angiosarcoma of the breast with an inflammatory appearance.