XRCC1, but not APE1 and hOGG1 gene polymorphisms is a risk factor for pterygium.

PurposeEpidemiological evidence suggests that UV irradiation plays an important role in pterygium pathogenesis. UV irradiation can produce a wide range of DNA damage. The base excision repair (BER) pathway is considered the most important pathway involved in the repair of radiation-induced DNA damage. Based on previous studies, single-nucleotide polymorphisms (SNPs) in 8-oxoguanine glycosylase-1 (OGG1), X-ray repair cross-complementing-1 (XRCC1), and AP-endonuclease-1 (APE1) genes in the BER pathway have been found to affect the individual sensitivity to radiation exposure and induction of DNA damage. Therefore, we hypothesize that the genetic polymorphisms of these repair genes increase the risk of pterygium.MethodsXRCC1, APE1, and hOGG1 polymorphisms were studied using fluorescence-labeled Taq Man probes on 83 pterygial specimens and 206 normal controls.ResultsThere was a significant difference between the case and control groups in the XRCC1 genotype (p=0.038) but not in hOGG1 (p=0.383) and APE1 (p=0.898). The odds ratio of the XRCC1 A/G polymorphism was 2.592 (95% CI=1.225-5.484, p=0.013) and the G/G polymorphism was 1.212 (95% CI=0.914-1.607), compared to the A/A wild-type genotype. Moreover, individuals who carried at least one C-allele (A/G and G/G) had a 1.710 fold increased risk of developing pterygium compared to those who carried the A/A wild type genotype (OR=1.710; 95% CI: 1.015-2.882, p=0.044). The hOGG1 and APE1 polymorphisms did not have an increased odds ratio compared with the wild type.ConclusionsXRCC1 (Arg399 Glu) is correlated with pterygium and might become a potential marker for the prediction of pterygium susceptibility

Current Situation and Future Prospect of the Standard System of Convenience Food in China

China's convenience food industry is developing rapidly. In recent years, the development of new product standards for convenience food has been continuously strengthened. Besides the approved industry standards such as “convenience dishes”, there are a number of industry standards currently being approved for development plan, which will effectively guide and standardize the industry's high-quality and healthy development. But on the whole, the product standard in this field needs to be revised and the product standard system needs to be further improved. By analyzing and interpreting the current standards and the standard system and the main contents of the newly formulated standards, this paper sorts out the main problems in the formulation and implementation of the standards, and puts forward the direction and suggestions for the construction of the standard system and its future revision, to facilitate the food industry’s product research and development, production and supervision to provide a technical basis

Multi-axial creep-fatigue life prediction considering history-dependent damage evolution : a new numerical procedure and experimental validation

In this paper, a new numerical procedure based on a cycle-by-cycle analysis has been constructed for creep-fatigue behavior and life prediction of high-temperature structures under multi-axial stress states. Within this framework, a modified unified viscoplastic constitutive model with isotropic hardening and modified kinematic hardening rules is developed to simulate the cycle-by-cycle stress-strain responses.Moreover, the newly constructed creep-fatigue approach calculates fatigue and creep damage variables using the critical plane method (CPM) and the modified strain energy density exhaustion (SEDE) model, respectively. The multi-axial ductility factor and elastic follow-up factor are also introduced into the modified SEDE model to accommodate the special multi-axial and mixed controlled modes, which are widely existed in practical structures. In order to validate the feasibility of the proposed numerical procedure, a series of creep-fatigue tests of notched specimens made from nickel-based GH4169 superalloy were carried out at 650 °C. The predicted numbers of cycles to crack initiation agree well with the experimental data. Evidence of crack initiation under various loading conditions was observed via the electron backscatter diffraction (EBSD) technique, indicating location-dependent crack initiations depending on loading conditions. In detail, the crack initiation sites shifting from surface to subsurface with increasing hold times can be well simulated by the proposed numerical procedure due to a reasonable description of the creep- fatigue damage evolution

A data analysis method for isochronous mass spectrometry using two time-of-flight detectors at CSRe

The concept of isochronous mass spectrometry (IMS) applying two time-of-flight (TOF) detectors originated many years ago at GSI. However, the corresponding method for data analysis has never been discussed in detail. Recently, two TOF detectors have been installed at CSRe and the new working mode of the ring is under test. In this paper, a data analysis method for this mode is introduced and tested with a series of simulations. The results show that the new IMS method can significantly improve mass resolving power via the additional velocity information of stored ions. This improvement is especially important for nuclides with Lorentz factor $\gamma$-value far away from the transition point $\gamma _t$ of the storage ring CSRe.Comment: published in Chinese Physics C Vol. 39, No. 10 (2015) 10620