Long-term stable platinum diselenide for nanosecond pulse generation in a 3-µm mid-infrared fiber laser.

In this paper, we fabricate the bulk-like multilayer platinum diselenide (PtSe2) and employ it as saturable absorber (SA) for a passively Q-switched fiber laser operating at 2865 nm for the first time, to the best of our knowledge. The nonlinear optical measurements of the bulk-like multilayer PtSe2 reveal efficient saturable absorption property at around 3 µm showing a modulation depth of 8.54% and a saturation intensity of 0.074 GW/cm2. By introducing the bulk-like PtSe2-SA into the Ho3+/Pr3+ co-doped ZBLAN fiber laser, stable Q-switched pulses with a duration as short as 620 ns are achieved at the pulse repetition rate of 238.1 kHz. The maximum average power is 93 mW, corresponding to a peak power of 0.63 W. The excellent long-term stability of the PtSe2-SA was also verified utilizing the same experimental setup after 40 days of ambient storage of the PtSe2 sample. The results not only validate the excellent nonlinear optical performance of PtSe2, but also indicate that the bulk-like PtSe2 is a promising long-term stable SA material under ambient conditions for nanosecond pulse generation in the 3-µm mid-infrared spectral region.

Linear Fuzzy Information-Granule-Based Fuzzy C-Means Algorithm for Clustering Time Series.

This article aims to design a trend-oriented-granulation-based fuzzy C -means (FCM) algorithm that can cluster a group of time series at an abstract (granular) level. To achieve a better trend-oriented granulation of a time series, l1 trend filtering is firstly carried out to result in segments which are then optimized by the proposed segment merging algorithm. By constructing a linear fuzzy information granule (LFIG) on each segment, a granular time series which well reflects the linear trend characteristic of the original time series is produced. With the novel designed distance that can well measure the trend similarity of two LFIGs, the distance between two granular time series is calculated by the modified dynamic time warping (DTW) algorithm. Based on this distance, the LFIG-based FCM algorithm is developed for clustering time series. In this algorithm, cluster prototypes are iteratively updated by the specifically designed granule splitting and merging algorithm, which allows the lengths of prototypes to change in the process of iteration. This overcomes the serious drawback of the existing approaches, where the lengths of prototypes cannot be changed. Experimental studies demonstrate the superior performance of the proposed algorithm in clustering time series with different shapes or trends.

Association of inflammatory and anti-inflammatory cytokines with insulin resistance in chronic hepatitis C.

BACKGROUND: The pathogenetic basis for the association between hepatitis C virus (HCV) infection and type-2 diabetes remains uncertain. It has been reported that insulin resistance (IR) plays an essential role. We investigated the association of inflammatory [tumour necrosis factor (TNF)-alpha, interleukin (IL)-6] and anti-inflammatory cytokines (adiponectin and IL-10) with IR in chronic HCV infection. METHODS: Eighty-one consecutive non-diabetic chronic hepatitis C patients (37 men and 44 women, mean age of 51.9+/-12.2 years) and 40 age, sex and body mass index (BMI)-matched healthy individuals were collected. IR was evaluated by the homoeostasis model assessment (HOMA). Serum levels of cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: Patients with chronic hepatitis C have a higher HOMA-IR, TNF-alpha, IL-6, adiponectin and IL-10, as compared with controls. By multiple linear regression analysis, moderate/severe steatosis grade, total cholesterol level and adiponectin was significantly associated with HOMA-IR, whereas, TNF-alpha, IL-6 and IL-10 was not. Male gender, BMI and HOMA-IR was inversely correlated with the serum adiponectin level. Serum adiponectin was positively correlated with TNF-alpha level, which was significantly associated with higher degree of hepatic necroinflammation. CONCLUSION: Our data suggest that chronic HCV infection is associated with increased IR, which is correlated inversely with the serum adiponectin level. The complex role of adiponectin in the pathogenesis of IR and hepatic necroinflammation in chronic HCV infection merit further investigation.

Steatosis correlates with hepatic expression of death receptors and activation of nuclear factor-kappaB in chronic hepatitis C.

BACKGROUND: Steatosis is recognized as a predictor of the severity as well as the progression of fibrosis in chronic hepatitis C. The mechanisms that cause increased hepatocellular injury associated with steatosis remain largely unknown. METHODS: We studied the correlation of hepatic expression of death receptors: Fas and tumour necrosis factor-alpha receptor 1 (TNF-R1), and downstream caspase (caspase-3) with hepatic steatosis by immunohistochemical study in chronic hepatitis C and determined the role of nuclear factor-kappaB (NF-kappaB). RESULTS: Ninety patients (49 males and 41 females, mean age of 50.5 +/- 10.4 years, genotype 1 or 2) with chronic hepatitis C virus infection were recruited. The factors associated with steatosis grade were body mass index (P=0.004) and fibrosis stage (P=0.034). Moderate/severe steatosis was an independent variable associated with advanced fibrosis stage by stepwise logistic regression analysis. The expression of immunoreactivity for Fas, TNF-R1 and active caspases-3 in liver tissues was significantly correlated with the steatosis grade (P<0.001, P<0.001 and P<0.001 respectively). The extent of active caspases-3 correlated significantly with the expression of Fas (r=0.659, P<0.001) and TNF-R1 (r=0.617, P<0.001). NF-kappaB p65 expression correlated significantly with the extent of Fas (r=0.405, P<0.001), TNF-R1 (r=0.448, P=0.002) and active caspase-3 (r=0.313, P=0.003), and correlated with steatosis grade (P<0.001) but not with inflammatory and fibrosis scores. CONCLUSION: Our observations suggest a mechanism whereby steatosis contributes to the progression of liver injury in chronic hepatitis C through upregulation of death receptors and activation of NF-kappaB.

Gender differences measured by the MATRICS consensus cognitive battery in chronic schizophrenia patients.

Using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), previous study showed significant gender differences for cognitive deficits in immediate and delayed memory in schizophrenia patients. However, RBANS does not include reasoning and problem solving, and social cognition. These cognitive functions can significantly affect the outcomes and daily life in patients. This study examined the gender differences of cognition using the measurement and treatment research to improve cognition in schizophrenia (MATRICS) consensus cognitive battery (MCCB), especially focusing on reasoning and problem solving, and social cognition in schizophrenia patients. The results showed that healthy controls exemplified better cognition than patients in both genders in all examined MCCB scores. Male healthy controls had better reasoning and problem solving and working memory than females, but these gender differences were not presented in schizophrenia patients. Also, male schizophrenia patients showed worse cognition than females on social cognition, processing speed, verbal learning and visual learning. Our results support that male schizophrenia patients had more cognitive impairment than females on reasoning and problem solving, social cognition, processing speed, working memory, verbal learning and visual learning.