A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydrogen ions, produced by a van de Graaff accelerator, in an energy range of 2.0-3.0 MeV, into an area smaller than that of the nucleus of an individual living cell. The beam is collimated by a borosilicate glass capillary that forms the beam-line exit. An integrated computer program recognizes the cells and locates them one by one over the microbeam exit for irradiation. We present technical details of the CAS-LIBB microbeam facility, particularly on the collimator, hardware, control program, as well as cell irradiation protocols available. Various factors contributing to the targeting and positioning precision are discussed along with accuracy measurement results.

The incidence of colorectal cancer (CRC) ranks third among all cancers in China and improvements in screening for CRC have an important impact on prevention and control of the disease. Paraoxonase 1 (PON1) is a calcium ion-dependent hydrolase that is widely distributed in tissue. Its diagnostic value in colorectal cancer has been reported, but the diagnostic value of combining PON1 with carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 12-5 (CA12-5) in colorectal cancer has not been evaluated. Experiments were carried out in a total of 284 CRC patients and 90 healthy controls. The primary cohort was randomly divided into training and validation sets. The levels of PON1 in plasma of CRC patients were significantly lower than that in the healthy controls (P < 0.001). It showed excellent diagnostic value with the AUC reaching 0.750 for the training set and 0.742 for the validation set. Furthermore, combining PON1 with CEA, CA12-5, CA19-9 could better classify CRC patients (AUC rising from 0.821, 0.716, 0.712 to 0.875, 0.817 and 0.814, respectively, in the training set, from 0.818, 0.581, 0.593 to 0.854, 0.770, and 0.772 in the validation set). In conclusion, PON1 can serve as a diagnostic biomarker for CRC and raise the sensitivity and specificity when incorporated with traditional tumor biomarkers.

Graphite tailings were used as the raw materials for the preparation of foamed ceramics via a high-temperature self-foaming method. The residual carbon in the tailings acted as the foaming agent and no additional foaming agents were required. The residual carbon reacted with Fe2O3 and produced gas that was wrapped by the liquid phase to form a porous structure. The effects of sintering temperature, holding time, carbon content, flux on the bulk density, water absorption, and mean pore size of the foamed ceramics were investigated. The bulk density, compressive strength, thermal conductivity, and water absorption of the foamed ceramic prepared using the optimal sample D100 (100 wt% graphite tailings) and sintered at 1200 °C for 20 min were 1.36 g/cm3, 0.35%, 12.03 MPa, and 0.51 W/(m·K), respectively. The raw material contained CaO, Fe2O3, and SiO2, which formed augite with a low fusibility point. In contrast, the molten decomposition products of potassium feldspar and CaSiO3 ions formed anorthite, which has a high fusibility point. Therefore, potassium feldspar is not recommended for use as a flux in tailing systems with high calcium content. Foamed ceramics were prepared using up to 100 wt% graphite tailings. This is a new approach for the economical disposal of graphite tailings.