177 research outputs found
Local and global avalanches in a 2D sheared granular medium
We present the experimental and numerical studies of a 2D sheared amorphous
material constituted of bidisperse photo-elastic disks. We analyze the
statistics of avalanches during shear including the local and global
fluctuations in energy and changes in particle positions and orientations. We
find scale free distributions for these global and local avalanches denoted by
power-laws whose cut-offs vary with inter-particle friction and packing
fraction. Different exponents are found for these power-laws depending on the
quantity from which variations are extracted. An asymmetry in time of the
avalanche shapes is evidenced along with the fact that avalanches are mainly
triggered from the shear bands. A simple relation independent from the
intensity, is found between the number of local avalanches and the global
avalanches they form. We also compare these experimental and numerical results
for both local and global fluctuations to predictions from meanfield and
depinning theories
tissue of rat adjuvant-induced arthritis
Triptolide has been clinically used to treat patients with rheumatoid arthritis, in which chemokine receptors play an important role in immune and inflammatory responses. To investigate the effect of triptolide on CCR5, we used complete Freund’s adjuvant to produce adjuvant-induced arthritis (AIA) in rats. Our data show that both CCR5 mRNA and protein levels in synovial tissue of rats with AIA are significantly higher than those in normal rats. Triptolide can significantly inhibit rat AIA-induced overexpression of CCR5 at both mRNA and protein levels. These results may contribute to better understanding of the therapeutic effects of triptolide in rheumatoid arthritis. Key words: triptolide, CCR5, adjuvant induced arthritis, rheumatoid arthriti
Determination of sunset yellow and tartrazine using silver and poly (L-cysteine) composite film modified glassy carbon electrode
Silver and poly(L-cysteine) composite film modified glassy carbon electrode (PLC/Ag/GCE) has been fabricated via cyclic voltammetry and used for investigation of the electrochemical behavior of sunset yellow (SY) and tartrazine (TT). A pair of anodic peak at 0.760 V (vs. Ag/AgCl) and cathodic peak at 0.701 V (vs. Ag/AgCl) for SY and an anodic peak at 1.013 V (vs. Ag/AgCl) of TT are observed in pH 4.5 phosphate buffer solution. Based on the two well-resolved anodic peaks of SY and TT, a novel electrochemical method has been successfully developed for simultaneous determination of SY and TT using differential pulse voltammetry. Under the optimized experimental conditions, the linear range for the determination of SY and TT are 5.00×10-7 –3.00×10-4 mol L-1 and 7.50×10-7–7.50×10-4 mol L-1, respectively with detection limits of 7.50×10-8 mol L-1 and 2.50×10-7 mol L-1, respectively. The proposed method has been applied for simultaneous determination SY and TT in beverage with satisfactory results
Performance of several simple, noninvasive models for assessing significant liver fibrosis in patients with chronic hepatitis B
Aim To compare the performance of several simple, noninvasive
models comprising various serum markers in diagnosing
significant liver fibrosis in the same sample of
patients with chronic hepatitis B (CHB) with the same judgment
standard.
Methods A total of 308 patients with CHB who had undergone
liver biopsy, laboratory tests, and liver stiffness
measurement (LSM) at the Southwest Hospital, Chongqing,
China between March 2010 and April 2014 were retrospectively
studied. Receiver operating characteristic (ROC)
curves and area under ROC curves (AUROCs) were used to
analyze the results of the models, which incorporated ageplatelet
(PLT) index (API model), aspartate transaminase
(AST) to alanine aminotransferase (ALT) ratio (AAR model),
AST to PLT ratio index (APRI model), γ-glutamyl transpeptidase
(GGT) to PLT ratio index (GPRI model), GGT-PLT-albumin
index (S index model), age-AST-PLT-ALT index (FIB-4
model), and age-AST-PLT-ALT-international normalized ratio
index (Fibro-Q model).
Results The AUROCs of the S index, GPRI, FIB-4, APRI, API,
Fibro-Q, AAR, and LSM for predicting significant liver fibrosis
were 0.726 (P < 0.001), 0.726 (P < 0.001), 0.621 (P = 0.001),
0.619 (P = 0.001), 0.580 (P = 0.033), 0.569 (P = 0.066), 0.495
(P = 0.886), and 0.757 (P < 0.001), respectively. The S index
and GPRI had the highest correlation with histopathological
scores (r = 0.373, P < 0.001; r = 0.372, P < 0.001, respectively)
and LSM values (r = 0.516, P < 0.001; r = 0.513,
P < 0.001, respectively). When LSM was combined with S
index and GPRI, the AUROCs were 0.753 (P < 0.001) and
0.746 (P < 0.001), respectively.
Conclusion S index and GPRI had the best diagnostic performance
for significant liver fibrosis and were robust predictors
of significant liver fibrosis in patients with CHB for
whom transient elastography was unavailable
Prognostic value of the distance between the primary tumor and brainstem in the patients with locally advanced nasopharyngeal carcinoma
BACKGROUND: Brainstem dose limitations influence radiation dose reaching to tumor in the patients with locally-advanced nasopharyngeal cancer (NPC). METHODS: A retrospective analysis of the prognostic value of the distance between the primary tumor and brainstem (Dbs) in 358 patients with locally-advanced NPC after intensity-modulated radiation therapy (IMRT). Receiver operating characteristic (ROC) curves were used to identify the cut-off value to analyze the impact of Dbs on tumor dose coverage and prognosis. RESULTS: The three-year overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) were 88.8 vs. 78.4 % (P = 0.007), 96.5 vs. 91.1 % (P = 0.018), 87.8 vs. 79.3 % (P = 0.067), and 84.1 vs. 69.6 % (P = 0.002) for the patients with the Dbs > 4.7 vs. ≤ 4.7 mm, respectively. ROC curves revealed Dbs (4.7 mm) combined with American Joint Committee on Cancer (AJCC) T classification had a significantly better prognostic value for OS (P < 0.05). CONCLUSIONS: Dbs (≤4.7 mm) is an independent negative prognostic factor for OS/LRFS/DFS and enhances the prognostic value of T classification in the patients with locally-advanced NPC
Expression Pattern of Serum Cytokines in Hepatitis B Virus Infected Patients with Persistently Normal Alanine Aminotransferase Levels
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