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Background: Breath analysis became promising for noninvasive diagnoses of cancer with sophisticated spectrometry technology introduced. This study aimed to screen volatile markers for hepatocellular carcinoma (HCC).Methods: Breath samples were collected from 30 HCC patients who were comorbid with type B hepatitis and cirrhosis and from 27 hepatocirrhosis patients and 36 healthy persons, both taken as controls. The volatile organic compounds in the samples were analyzed with gas chromatography/mass spectrometry and the markers were selected by comparing their levels between groups. Each of the markers was evaluated by receiver operating characteristic (ROC) curves and a discriminant function using the markers was established. The relationships of α-fetoprotein (AFP) levels and clinical stages with the concentrations of the markers were also investigated.Results: 3-Hydroxy-2-butanone, styrene, and decane were screened as potential markers, among which 3-hydroxy-2-butanone was found to have the best diagnostic value. The diagnostic function using these markers had a sensitivity of 86.7% and a specificity of 91.7% between HCC patients and normal controls and a sensitivity of 83.3% and a specificity of 91.7% by cross-validation. No statistically significance (P > 0.05) was found for the concentration differences of these markers between HCC patients with AFP >400 or <400 μg/L or between stage I-II and stage III-IV patients.Conclusion: These volatile organic compounds could be useful as breath markers of HCC patients, independent of AFP levels or clinical stages.Impact: Breath analysis could be useful for early diagnosis of HCC, especially for AFP-negative HCC.

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We have deposited hydrogen-free diamond-like amorphous carbon films by ArF (193 nm) pulsed laser ablation of graphite. The deposition process is performed with a laser power density of only 5 × 108 W/cm2 at room temperature without any auxiliary energy source incorporation. The resulting films possess remarkable physical, optical, and mechanical properties that are close to those of diamond and distinct from the graphite target used. The films have a mechanical hardness up to 38 GPa, an optical energy band gap of 2.6 eV, and excellent thermal stability. Analysis of electron energy loss spectroscopy reveals the domination of diamond-type tetrahedral bonding structure in the films with the sp3 bond fraction over 95%. Compared with other reported results of pulsed-laser-deposited diamond-like carbon films, our experimental results confirm that the laser wavelength or photon energy plays a crucial role in controlling the properties of the pulsed-laser-deposited diamond-like carbon films.

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Space-filling and projective properties are desired features in the design of computer experiments to create global metamodels to replace expensive computer simulations in engineering design. The goal in this article is to develop an efficient and effective sequential Quasi-LHD (Latin Hypercube design) sampling method to maintain and balance the two aforementioned properties. The sequential sampling is formulated as an optimization problem, with the objective being the Maximin Distance, a space-filling criterion, and the constraints based on a set of pre-specified minimum one-dimensional distances to achieve the approximate one-dimensional projective property. Through comparative studies on sampling property and metamodel accuracy, the new approach is shown to outperform other sequential sampling methods for global metamodelling and is comparable to the one-stage sampling method while providing more flexibility in a sequential metamodelling procedure.