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ObjectiveTo tentatively understand the status of radioactive contamination in nuclear medicine personnel.MethodsA total of 34 radiation staff engaged in nuclear medicine diagnosis and treatment were selected from two hospitals in Shanghai as the survey subjects.Among the 34 medical staff， 8 were nuclear medicine doctors， 14 were nuclear medicine technicians and 12 were nuclear medicine nurses. After surface contamination monitoring was first carried out to confirm that they had no surface radioactivity contamination， whole body scanning was performed with a whole body counter to determine whether they were internally contaminated with artificial radionuclides.ResultsThe α surface contamination was not detected in the nuclear medical staff. The β surface contamination of the nuclear medicine doctors， technicians and nurses was （13.8±0.8）， （14.1±0.8） and （14.0±0.7） times per second， respectively. There were 2， 2， and 4 nuclear medicine doctors who were contaminated with 18F， 99mTc and 131I， 3， 5， and 2 nuclear medicine technicians who were contaminated with 18F， 99mTc and 131I， and 6， 8， and 5 nuclear medicine nurses who were contaminated with 18F， 99mTc and 131I， respectively. The 18F activity of nuclear medicine technicians was 1 997‒9 401 Bq， and the 99mTc activity of nuclear medicine technicians and nurses was 3 699‒18 692 and 652‒388 22 Bq， respectively. One nuclear medicine nurse had a 99mTc activity of 35 389 Bq. According to the preliminary estimation of 131I internal irradiation dose， the maximum committed effective dose of nuclear medicine doctors， technicians and nurses could reach 0.370， 0.018 and 0.584 mSv， respectively.ConclusionThe nuclear medicine staff are exposed to radioactive contamination， and it is important to monitor and evaluate their internal radiation doses.

The calculation of multiscale elastic parameters of cementitious materials based on micromechanical tests and the composite material theory is one of the key theoretical bases for precise design of cementitious materials performance. In this paper, grid nanoindentation tests of microscopic elastic modulus and the mercury intrusion test were conducted on hardened cement paste specimens at different water-cement ratios, to establish a multiscale homogenization calculation method for the elastic modulus of cement paste considering the influence of pores. Besides, the applicability of the dilute method, the self-consistent method, the Mori-Tanaka method, the interaction direct derivation (IDD) method, and the multilevel homogenization method was compared. The results show that the multi-phase and multi-scale calculations considering the effect of pores is in good agreement with experimental values. Except the multi-level homogenization method, the calculation results of several commonly used composite homogenization methods are similar.

Collision breast tumors, consisting of breast cancer (BC) and non-Hodgkin’s lymphoma (NHL), are extremely rare. Here we report the case of a 64-year-old woman with a collision tumor in her left breast mass that was composed of invasive ductal carcinoma and small lymphocytic lymphoma/chronic lymphocytic leukemia. In addition, we reviewed the published comparable English-language literature. Collision breast tumor composed of BC and NHL is extremely rare. For that reason, there is a lack of consensus about the underlying mechanism, and diagnosing it without delay remains a complex clinical challenge. We found that post-menopausal, age-related estrogen levels changes and Epstein-Barr virus infection are possible pathogenic factors. However, the symptoms are almost identical, and it is difficult to distinguish a simple breast tumor from a breast collision tumor. In this study, we reviewed the clinical features of all patients with BC and NHL colliding breast tumors; this information might enable early identification and prevention of misdiagnosis.

In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.

This study uses 7075 aluminum alloy as the base material and employs micro arc oxidation technology to prepare ceramic coatings with different concentrations of graphene particles on the surface of the 7075 aluminum alloy. The effects of graphene particle concentration on micro arc oxidation behavior and coating performance were investigated through X‐ray diffraction, scanning electron microscope, electrochemical testing, and other performance characterization methods. The research results show that the addition of graphene particles helps to promote the transformation of metastable γ‐Al2O3 to stable α‐Al2O3, thereby enhancing the corrosion properties of the coating. When the concentration of graphene particles is 3 g/L, the prepared micro arc oxidation coating has the maximum thickness and hardness, which are 17.13 µm and 886.76 HV0.3, respectively, while the porosity and roughness are the smallest, which are .39 µm and 4.79%, respectively. Electrochemical test results show that the self‐corrosion current density is the smallest at this concentration, which is 2.323 × 10−9A/cm2. Therefore, the addition of graphene particles can effectively improve the corrosion properties of 7075 aluminum alloy. [ABSTRACT FROM AUTHOR]

In order to enhance the corrosion and wear resistance of aluminum alloys in complex and variable environments, an Al2O3 ceramic film was prepared on the surface of 7A04 aluminum alloy in a silicate electrolyte system using a micro‐arc oxidation technique. Subsequently, antimony tin oxide (ATO) nanoparticles were used to dope the micro‐arc oxidation film to enhance the protective properties of the 7A04 aluminum alloy. The structural characteristics of the film were investigated by examining the surface and cross‐sectional morphology and the composition of the physical phases. The results show that ATO nanoparticles can promote the micro‐arc oxidation reaction, improve the surface morphology of the film layer, increase the thickness of the film layer and the denseness after sintering, and enter the film layer in the form of melt wrapping, which plays a role in refining the grain. In the study of the wear resistance and corrosion resistance of ATO‐doped ceramic film layers, it was found that the introduction of ATO nanoparticles did not significantly improve the wear resistance of the micro‐arc oxide ceramic film layers but significantly improved the corrosion resistance of the film layers. [ABSTRACT FROM AUTHOR]