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Hydrofluorocarbon gas chemistries have long been favored for SiO2 etching. However, the fluorocarbon polymer generated during the process not only assists in obtaining a high selectivity, but also leads to chamber wall contamination. The adhesion efficiency of the polymer depends on the chamber wall temperature, which needs to be well-controlled to ensure controllable polymer deposition rate and etch characteristics. Similarly, the increasing gas temperature during the process is also expected to increase the production rate of polymer precursors. Hence, it is important to properly condition the chamber so that a sufficiently high and stable chamber temperature is reached before starting the actual process. This work utilizes an Inductively Coupled Plasma Reactive Ion Etcher to optimize a multi-cycle chamber conditioning process for two C4F8/H2-based chemistries. We use the integrated optical emission spectroscopy (OES) tool to show that the dependence of etch characteristics on conditioning time is much stronger for the highly polymerizing chemistry. For a low conditioning time (< 15 min), the instability of plasma species indicate that the chamber temperature has not yet plateaued, resulting in a ⁓60% decrease of recess in the underlying silicon layer during the lot processing time. By conducting systematic etch tests, we analyze the behavior of key OES peaks to identify the optimal conditioning time (≥ 30 min) for this recipe, which results in only a 13% decrease in silicon recess depth during the processing time. Subsequently, a method to assess the stability of plasma species during the conditioning process is devised, assisting in advance to identify the optimal moment to initiate the lot process. By comparing the experimental results of the two etch recipes, we also highlight the important correlation between conditioning time and polymerizing degree of the chemistry. [ABSTRACT FROM AUTHOR]

Nuclear fusion between protons and boron-11 nuclei has undergone a revival of interest thanks to the rapid progress in pulsed laser technology. Potential applications of such reaction range from controlled nuclear fusion to radiobiology and cancer therapy. A laser-driven fusion approach consists in the interaction of high-power, high-intensity pulses with H- and B-rich targets. We report on an experiment exploiting proton-boron fusion in CN-BN targets to obtain high-energy alpha particle beams (up to 5 MeV) using a very compact approach and a tabletop laser system with a peak power of ~10 GW, which can operate at high-repetition rate (up to 1 kHz). The secondary resonance in the cross section of proton-boron fusion (~150 keV in the center-of-mass frame) is exploited using a laser-based approach. The generated alpha particles are characterized in terms of energy, flux, and angular distribution using solid-state nuclear-track detectors, demonstrating a flux of ~105 particles per second at 10 Hz, and ~106 per second at 1 kHz. Hydrodynamic and particle-in-cell numerical simulations support our experimental findings. Potential impact of our approach on future spread of ultra-compact, multi-MeV alpha particle sources driven by moderate intensity (1016-1017 W/cm2) laser pulses is anticipated. Revived interest in proton-boron fusion has been fuelled by new laser matter interaction schemes with several possible applications. The authors report on a tabletop laser experiment that observes proton-boron fusion with an emphasis on the secondary cross-section peak around 150 keV. [ABSTRACT FROM AUTHOR]

The serum levels of soluble HLA class I antigens (sHLA-A, -B, -C and sHLA-G) were determined in 40 HCV genotype 1-infected patients before ( T ), after 3, 6, and 12 months ( T , T , and T ) of pegylated-IFN-α plus ribavirin therapy and 6 months ( T ) after the end of treatment. Twenty patients were sustained virological responders (SVR), and 20 were non-responders (NR). sHLA-A, -B, -C levels at T were significantly higher in both SVR (mean 10.48 μg/ml) and NR (mean 11.87 μg/ml) patients as compared to healthy controls (mean 0.34 μg/ml, p < 0.0001) and HIV-infected subjects (mean 1.22 μg/ml, p < 0.0001). sHLA-G levels at T were significantly higher in SVR (mean 24.78 ng/ml) and NR (mean 24.93 ng/ml) patients as compared to healthy controls (mean 10.34 ng/ml, p = 0.015 and p = 0.014, respectively) but were lower as compared to HIV-infected subjects (mean 48.00 ng/ml, p < 0.0001). The levels of sHLA-A, -B, -C and sHLA-G significantly decreased in SVR from T to T (mean 1.64 and 1.43 ng/ml, respectively, p < 0.0001) and correlated with HCV-RNA, AST, ALT, γGT, and ALP levels. The determination of soluble HLA class I levels could be proposed as a surrogate marker to discriminate SVR and NR HCV-infected patients during PEG-IFN-α plus ribavirin therapy. [ABSTRACT FROM AUTHOR]

Pharmacokinetics and dose-finding studies on sorafenib were conducted on heterogeneous groups of patients with solid tumors. Portal hypertension, gut motility impairment and altered bile enterohepatic circulation may explain different sorafenib toxicological profile in cirrhotic patients. This study evaluated sorafenib plasma concentration in a homogeneous group of cirrhotic patients with hepatocellular carcinoma (HCC). Sorafenib concentrations were determined by liquid chromatography in 12 consecutive patients. Data have been evaluated by the generalized estimating equations method ( p value statistical level was set at α = 0.05). (1) There were not significant differences between sorafenib concentrations in patients who tolerate the full dose versus patients with reduced dose due to toxicity; (2) the average sorafenib concentrations measured 3 h after the morning dosing were lower than those measured 12 h after the evening dosing ( p = 0.005); (3) sorafenib concentrations decrease overtime ( p < 10); (4) it has been found an association between the development of severe adverse reactions and sorafenib concentrations ( p < 10). The relationship between dose and concentration of sorafenib in HCC patients is poor and not clinically predictable, confirming the variability both in the maximum tolerated dose and in plasma concentrations. Several factors may influence the pharmacokinetics in patients with liver disease. This may explain the inter-patient variability of concentrations and the lack of differences in concentration at different dosages. It could be interesting to extend the series of HCC patients to enhance information on the kinetics of the drug; furthermore, to establish a threshold of plasma sorafenib concentrations to predict severe adverse reactions would be clinically useful. [ABSTRACT FROM AUTHOR]

Background: Elderly patients with chronic hepatitis C virus (HCV) infection represent an understudied population, and little is known regarding the predictive factors for sustained virological response (SVR) to antiviral therapy in these patients.Aims: To evaluate the efficacy of pegylated interferon (PEG-IFN) and ribavirin therapy in chronic HCV patients aged 65 years, and identify pre- and on-treatment predictors of SVR.Methods: We studied 57 patients aged ≥65 years who underwent PEG-IFN and ribavirin treatment, evaluating the SVR rate and its association with pre-treatment demographic, clinical, biochemical, and virological parameters. Furthermore, we assessed whether 12-week serum HCV-RNA assessment might predict SVR.Results: A SVR was obtained in 25 patients (45%). The only pre-treatment predictor of SVR was HCV genotype 2 and 3 (P = 0.02). A positive serum HCV-RNA or a decline in viral load ≤2log(10) at week 12 had 100% negative predictive value for SVR. No major liver-related events or deaths occurred during therapy. Treatment was discontinued due to side effects-mainly cardiovascular-in 10 patients (17%).Conclusion: Pre- and on-treatment virological parameters can be used to identify elderly patients who are more likely to obtain a SVR to standard-of-care antiviral therapy for chronic HCV infection. [ABSTRACT FROM AUTHOR]

The serum levels of soluble β2-μ-associated and β2-μ-free HLA class I heavy chains were determined in 28 interferon-α nonresponder chronic hepatitis C patients retreated with interferon-α plus ribavirin and in 70 healthy subjects. The baseline levels of β2-μ-associated and β2-μ-free HLA class I heavy chains were significantly higher in patients than in healthy controls (P = 0.001). The levels of β2-μ-associated HLA class I heavy chains significantly increased in responder patients with respect to nonresponders at the third month of treatment (P = 0.03). At the sixth month of treatment and after 6 months of follow up the levels of β2-μ-associated HLA class I heavy chains decreased in responder patients and increased in nonresponders. The levels of β2-μ-free HLA class I heavy chains showed only minor changes during and after treatment. We suggest that the determination of hepatitis C virus RNA levels combined with soluble β2-μ-associated HLA class I heavy chains, as a marker of immune activation, could identify interferon-α non responder chronic hepatitis C patients most likely to respond to a retreatment with interferon-α plus ribavirin. [ABSTRACT FROM AUTHOR]

We studied 2253 consecutive dyspeptic patients, without clinical evidence of organic disease, who were referred to our open access endoscopy service. The aim was to assess whether the various clinical patterns of dyspepsia can be considered a valid guidelines for the appropriate use of endoscopy. According to the symptomatological patterns, our patients were defined as sufferers from 1) ulcer-like (973 patients). 2) reflux-like (857), and 3) dysmotility-like dyspepsia (423). In our patient population, which reflects the general population of our city, the dysmotility-like type of dyspepsia was the least frequent (19%), whereas the ulcer-like (43%) and the reflux-like (38%) dyspepsia were almost equivalent. A negative endoscopy (35.7%) occurred significantly (p ≤ 5 x 10-4) more often in dysmotility-like than in ulcer-like (26.3%) and reflux-like dyspepsia (25.7%). Furthermore, in dysmotility-like dyspepsia, we observed no malignancies in patients less than 60 yr old. and no gastric ulcers in patients less than 50 yr old. In the latter subgroup of patients (under 50 yr), duo-denal ulcers and esophagitis were rare (occurring in only one and five, respectively, out of 145 patients). In ulcer-like and reflux-like dyspepsia, abnormal endoscopic findings occurred frequently (in 73.5%) and 74.1%, respectively), and no relationship with patients' age was observed. Our data indicate that patients under 50 yr old with dysmotility-like dyspepsia can be considered a kind of population for which endoscopy is inappropriate. However, because the prevalence of dysmotility-like dyspepsia was 19% (423/2253) in our patient sample, and only 7.15% of them were under 50 yr old (161/2253), we can obtain only a small percentage of reduction in endoscopic service load if the guideline of age ≤ 50 yr is adopted. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor on hepatitis G virus and hepatitis C virus related extrahepatic disease.

Liver biopsies were performed on 60 patients by means of percutaneous needle biopsy, and immediately after that procedure, during laparoscopy from the right and left liver lobes. The histological diagnoses obtained by examining the percutaneous biopsies were found to overlap with the final one that was based on an evaluation of all three liver biopsies. Moreover, highly significant correlation was found to exist between the scores of histological parameters of inflammation, fibrosis, necrosis, and steatosis. [ABSTRACT FROM AUTHOR]