Hyperspectral microscopy of two-dimensional semiconductors

Here we present an interferometric wide field hyperspectral microscope based on a common-path birefringent interferometer with translating wedges, to measure photoluminescence emission from two-dimensional semiconductors. We show diffraction-limited hyperspectral photoluminescence microscopy from two-dimensional materials across millimeter areas, proving that our hyperspectral microscope is a compact, stable and fast tool to characterize the optical properties and the morphology of 2D materials across ultralarge areas

NT pro BNP plasma level and atrial volume are linked to the severity of liver cirrhosis.

BACKGROUND AND AIMS: Plasma levels of NT-pro-BNP, a natriuretic peptide precursor, are raised in the presence of fluid retention of cardiac origin and can be used as markers of cardiac dysfunction. Recent studies showed high levels of NT pro BNP in patients with cirrhosis. We assessed NT pro-BNP and other parameters of cardiac dysfunction in patients with cirrhosis, with or without ascites, in order to determine whether the behaviour of NT pro BNP is linked to the stage of liver disease or to secondary cardiac dysfunction. METHODS: Fifty eight consecutive hospitalized patients mostly with viral or NAFLD-related cirrhosis were studied. All underwent abdominal ultrasound and upper GI endoscopy. Cardiac morpho-functional changes were evaluated by echocardiography and NT-pro-BNP plasma levels determined upon admission. Twenty-eight hypertensive patients, without evidence of liver disease served as controls. RESULTS: Fifty eight cirrhotic patients (72% men) with a median age of 62 years (11% with mild arterial hypertension and 31% with type 2 diabetes) had a normal renal function (mean creatinine 0.9 mg/dl, range 0.7-1.06). As compared to controls, cirrhotic patients had higher NT pro-BNP plasma levels (365.2±365.2 vs 70.8±70.6 pg/ml; p<0.001). Left atrial volume (LAV) (61.8±26.3 vs 43.5±14.1 ml; p = 0.001), and left ventricular ejection fraction (62.7±6.9 vs. 65.5±4%,; p = 0.05) were also altered in cirrhotic patients that in controls. Patients with F2-F3 oesophageal varices as compared to F0/F1, showed higher e' velocity (0.91±0.23 vs 0.66±0.19 m/s, p<0.001), and accordingly a higher E/A ratio (1.21±0.46 vs 0.89±0.33 m/s., p = 0.006). CONCLUSION: NT-pro-BNP plasma levels are increased proportionally to the stage of chronic liver disease. Advanced cirrhosis and high NT-pro-BNP levels are significantly associated to increased LAV and to signs of cardiac diastolic dysfunction. NT pro-BNP levels could hence be an useful prognostic indicators of early decompensation of cirrhosis

Strong Coupling of Coherent Phonons to Excitons in Semiconducting Monolayer MoTe2_2

The coupling of the electron system to lattice vibrations and their time-dependent control and detection provides unique insight into the non-equilibrium physics of semiconductors. Here, we investigate the ultrafast transient response of semiconducting monolayer 2$H$-MoTe$_2$ encapsulated with $h$BN using broadband optical pump-probe microscopy. The sub-40-fs pump pulse triggers extremely intense and long-lived coherent oscillations in the spectral region of the A' and B' exciton resonances, up to $\sim$20% of the maximum transient signal, due to the displacive excitation of the out-of-plane $A_{1g}$ phonon. Ab-initio calculations reveal a dramatic rearrangement of the optical absorption of monolayer MoTe$_2$ induced by an out-of-plane stretching and compression of the crystal lattice, consistent with an $A_{1g}$-type oscillation. Our results highlight the extreme sensitivity of the optical properties of monolayer TMDs to small structural modifications and their manipulation with light.Comment: 27 pages, 4 figures, supporting informatio

Nonlinear interactions of dipolar excitons and polaritons in MoS2 bilayers

Nonlinear interactions between excitons strongly coupled to light are key for accessing quantum many-body phenomena in polariton systems. Atomically-thin two-dimensional semiconductors provide an attractive platform for strong light-matter coupling owing to many controllable excitonic degrees of freedom. Among these, the recently emerged exciton hybridization opens access to unexplored excitonic species, with a promise of enhanced interactions. Here, we employ hybridized interlayer excitons (hIX) in bilayer MoS2 to achieve highly nonlinear excitonic and polaritonic effects. Such interlayer excitons possess an out-of-plane electric dipole as well as an unusually large oscillator strength allowing observation of dipolar polaritons(dipolaritons) in bilayers in optical microcavities. Compared to excitons and polaritons in MoS2 monolayers, both hIX and dipolaritons exhibit about 8 times higher nonlinearity, which is further strongly enhanced when hIX and intralayer excitons, sharing the same valence band, are excited simultaneously. This gives rise to a highly nonlinear regime which we describe theoretically by introducing a concept of hole crowding. The presented insight into many-body interactions provides new tools for accessing few-polariton quantum correlations

Extrahepatic spread of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major health problem. The treatment of HCC depends on the tumour stage and on the severity of underlying cirrhosis, however, a majority of HCC patients have advanced disease at presentation. In recent years extra-hepatic spread (ES) of HCC seems to have been observed more frequently than in the past even if few data exist in literature on prevalence, clinical presentation and prognosis of patients with HCC ES. Aim of this brief review is underline the main concerns, pitfalls and warnings in practicing with these patients. ES of HCC are not rare, and the probability of finding ES is higher in patients with advanced intra-hepatic HCC. The more frequent ES sites are lung lymph nodes and bones, but also the head and neck district can be affected. The prognosis of HCC patients with ES is poor and sorafenib seems to be the only therapeutic option

Causes of and prevention strategies for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a challenging malignancy of global importance. It is associated with a high rate of mortality and its prevalence in the United States and in Western Europe is increasing. Cirrhosis is the strongest and the most common known risk factor for HCC, usually due to hepatitis C virus (HCV) and hepatitis B virus (HBV) infections. However, different lines of evidence identify in non-alcoholic fatty liver disease (NAFLD) a possible relevant risk factor for occurrence of HCC. Given the continuing increase in the prevalence of obesity and diabetes, the incidence of non-alcoholic steatohepatitis-related HCC may also be expected to increase, and a potential role of behavior treatment and/or insulin-sensitizing drugs can be envisaged. Vaccination against HBV is the most efficient primary prevention measure currently available to reduce the HCC incidence and mortality in high-incidence areas, while data on the role of interferon (IFN) and nucleos(t)ide analogues (NUC) are still controversial. The pooling of data from the literature suggests a slight preventive effect of antiviral therapy on HCC development in patients with HCV-related cirrhosis, but the preventive effect is limited to sustained virological responders

Raw dataset for: High-throughput multimodal wide-field Fourier-transform Raman microscope

This is the Raw spectral dataset of the data published in 10.1364/OPTICA.488860 Data are arranged as follows: wavenumber [Nx1] Hyperspectrum_cube [Nx2, A, B]: hyperspectral datacube, where: Hyperspectrum_cube (1:N, :, :) is the real part; Hyperspectrum_cube (N+1:2N, :, :) is the imaginary part maximum [1x1] minimum [1x1]. N: number of spectral bands A and B: size of the spatial coordinates Spectral amplitudes are obtained by: Hyperspectrum_cube=double(Hyperspectrum_cube)./(2.^16-1).*maximum+minimu

Natural history of untreatable hepatocellular carcinoma: A retrospective cohort study

Abstract AIM: To investigate the clinical course of untreatable hepatocellular carcinoma (HCC) identified at any stage and to identify factors associated with mortality. METHODS: From January 1999 to December 2010, 320 out of 825 consecutive patients with a diagnosis of HCC and not appropriate for curative or palliative treatments were followed and managed with supportive therapy. Cirrhosis was diagnosed by histological or clinical features and liver function was evaluated according to Child-Pugh score. The diagnosis of HCC was performed by Ultra-Sound guided biopsy or by multiphasic contrast-enhanced computed tomography or gadolinium-enhanced magnetic resonance imaging. Data were collected for each patient including all clinical, laboratory and imaging variables necessary for the outcome prediction staging systems considered. HCC staging was performed according Barcelona Clinic Liver Cancer (BCLC) and Cancer of the Liver Italian Program scores. Follow-up time was defined as the number of months from the diagnosis of HCC to death. Prognostic baseline variables were analyzed by multivariate Cox analysis to identify the independent predictors of survival. RESULTS: Seventy-five per cent of patients had hepatitis C. Ascites was present in 169 patients (53%), while hepatic encephalopathy was present in 49 patients (15%). The Child-Pugh score was class A in 105 patients (33%), class B in 142 patients (44%), and class C in 73 patients (23%). One hundred patients (31%) had macroscopic vascular invasion and/or extrahepatic spread of the tumor. A single lesion > 10 cm was observed in 34 patients (11%), while multinodular HCC was present in 189 patients (59%). Thirty nine patients (12%) were BCLC early (A) stage, 55 (17%) were BCLC intermediate (B) stage, 124 (39%) were BCLC advanced (C) stage, and 102 (32%) were endstage BCLC (D). At the time of this analysis (July 2011), 28 (9%) patients were still alive. Six (2%) patients who were lost during follow-up were censored at the last visit. The overall median survival was 6.8 mo, and the 1-year survival was 32%. The 1-year survival according to BCLC classes was 100%, 79%, 12% and 0%, for BCLC A, B, C and D, respectively. There was a significant difference in survival between each BCLC class. The median survival of patients of BCLC stages A, B, C and D was 33, 17.4, 6.9, and 1.8 mo, respectively (P < 0.05 for comparison between stages). The median survival of Child-Pugh A, B and C classes were 9.8 mo (range 6.4-13), 6.1 (range 4.9-7.3), and 3.7 (range 1.5-6), respectively (P < 0.05 for comparison between stages). By univariate analysis, the variables significantly associated to an increased liklihood of mortality were Eastern Cooperative Oncology Group performance status (PS), presence of ascites, low level of albumin, elevated level of bilirubin, international normalized ratio (INR) and Log-[(α fetoprotein (AFP)]. At multivariate analysis, mortality was independently predicted by bad PS (P < 0.0001), high INR values (P = 0.0001) and elevated Log-(AFP) levels (P = 0.009). CONCLUSION: This study confirms the heterogeneous behavior of untreated HCC. BCLC staging remains an important prognostic guide and may be important in decision-making for palliative treatment