[en] Objective: To investigate and analyze the current situation of clinical nuclear medicine in Shijiazhuang, and provide feasible suggestions. Methods: Questionnaire and field surveys were carried out to investigate the status of medical institutions with clinical nuclear medicine departments. The questionnaire included basic information of medical institutions, basic information of the departments, the staff and radiation protection managements; the field investigation included the process layout and the radiation protection facilities. Results: There were 6 medical institutions in Shijiazhuang and 12 nuclear medical imaging devices. There were 92 nuclear medicine staff, but they were no nuclear physicists, radiochemists or engineers. The building area of 7 nuclear medicine workplace was small, and 4 of them had some problems in the layout process. The radiation protection management for the medical staff in nuclear medicine department was fairly good. Conclusion: To improve the quality and professional knowledge of nuclear medicine practitioners and to optimize the layout process of nuclear medicine clinics are of great significance for promoting the development of nuclear medicine. To strengthen the radiation protection management in the nuclear medicine discipline can make up for the defects of the layout process to a certain extent. (authors)

[en] Objective: Through analysis of external individual doses to radiation workers in medical system in Shijiazhuang in 2016, to find the problems in individual monitoring so as to provide related proposals to further standardize the wearing of personal dosimeters for radiation workers. Methods: According to the requirements of the Specification for Individual Monitoring of Occupational External Radiation (GBZ 128-2016), the Li F (Mg, Cu, P) thermoluminescence dosimeter was used to monitor the external individual dose of radiation workers by Shijiazhuang Occupational Disease Prevention and Treatment Hospital, and relevant data in 2016 were collected and statistically analyzed. Results: A total of 3749 radiation workers were monitored, and the effective monitoring rate was 63%. The per capita annual dose equivalent of 2362 radiation workers was 1.55 mSv/a, and the highest value of 1.82 mSv/a was found in nuclear medicine workers. There was overlap in the 95% confidence interval of the effective dose for different types of radiation workers, the relative expanded uncertainty were all around 14%, and the difference of individual dose was statistically significant among different working types (P < 0.01). Conclusion: The level of individual dose for radiation workers in medical system in Shijiazhuang City in 2016 basically met the requirements of national standard. However, the individual monitoring should be further strengthened for the nuclear medicine and interventional radiology staff. (authors)

[en] One-step printing of electrically conductive inks on textiles is one of the simplest and most prospective methods to manufacture functional wearable electronics. However, the high surface roughness and porous structure as well as poor temperature endurance of most textiles have become the major challenges for the realization of printed electronic textiles (E-textiles). To solve these issues, the UV curable conductive ink with fast curing and low temperature characteristics was formulated to fabricate the flexible fabric-based conductive patterns using screen printing method. The specific focus was spent on investigating the effect of ink composition on curing speed, film forming ability, morphological characteristics and electrical properties of conductive patterns directly printed on fabric substrates. Firstly, we determined the necessity of defoamer for the formation of uniform and continuous printed textile-based patterns, and optimized the film forming ability of UV-curing ink by exploring the defoamer performance. Then, the ink curing speed was found heavily depending on the different types and contents of photoinitiators. Finally, the nano-silver loading showed critical influence to the screen-printability and the electrical properties of printed patterns. An ink formulation with 60 wt% nano-silver, 4 wt% photoinitiator (1173), and 0.2 wt% defoamer (BYK-555) showed satisfactory screen printability, and the conductive patterns with 1.0 mm width exhibited a remarkably low resistivity of 4.04 × 10⁻⁵ Ω cm. Moreover, the high performance of the conductive pattern screen-printed on four different fabrics by the formulated UV curable conductive ink further demonstrated its application potential. The results showed that uniformity and electrical properties of printed patterns were directly related to the weaving method, texture characteristic, and roughness of the textiles. We believe these results will provide basic guidance for the formulation design of conductive ink and facilitate the utility of textiles-based wearable electronics. (paper)

[en] Bermuda grass (Cynodon dactylon) can endure long-term and deep submergence stress and cadmium toxicity, respectively. But we do not know whether they can endure cadmium plus waterlogging and what are the differences of ecophysiological responses and metal bio-accumulation of Bermuda grass subjected to normal condition, waterlogging, cadmium or cadmium-and-waterlogging treatments, respectively. Here, the four treatments on Bermuda grass are performed with four replications. Our objective is to determine the ecophysiological responses and endurance abilities, cadmium and zinc bio-concentration and translocation, and the metal uptake mechanisms of Bermuda grass subjected to the four treatments. Our results demonstrated different treatments showed different ecophysiological responses in Bermuda grass. The shoot weights of cadmium treatment were significantly lower than those of the other treatments when the values determined after treated 25 d. Cadmium had a certain promotion effect on the root growth at the early growth stage. SPAD values indicate the relative amounts of chlorophyll present in plant leaves. SPAD value of 35 d was higher than 25 d of cadmium treatment, indicating cadmium had negative effects on chlorophyll contents in the early stage, but the negative effects might be ameliorated as plants adapted to cadmium stress. Waterlogging induced the biomass decrease and accelerated cadmium translocation. The plant leaves had the highest cadmium contents exposed to cadmium-and-waterlogging treatment, while the root showed the highest cadmium contents suffered only cadmium stress. The bio-concentration factor of cadmium-and-waterlogging treatment was less than that of cadmium treatment, but the translocation factor of cadmium-and-waterlogging treatment was much greater than that of cadmium treatment, which indicated phytostabilization was the main phytoremediation process subjected to only cadmium stress, while phytoextraction was the main process when exposed to cadmium-and-waterlogging treatment. Bermuda grass was a cadmium hyperaccumulator and had strong adaptability to waterlogging, cadmium toxicity or both.

[en] objective: To master the present situation of radiation protection in some nuclear medicine workplaces and radiation workers in Hebei Province and to provide data support for strengthening radiological health supervision and developing standards related to nuclear medicine. Methods: Ambient dose equivalent rates were measured by X and gamma radiation dosimeters for 16 nuclear medicine workplaces in Hebei Province, and beta surface contamination of workplaces and staff were measured by alpha and beta surface contaminators; The deep individual dose equivalent H_p (10) of 77 nuclear medical staff was monitored by thermoluminescence dose method, and occupational health test reports of the 77 nuclear medical staff were reviewed in the recent two years. Results: There was statistical difference in the radiation level between all detection points in the SPECT (/CT) workplace (F = 32.02, P < 0.05), in which the ambient dose equivalent rates of the administration window (nurse operating position) was the highest. which was 11.92 to 37.77 μSv/h, with an average of (19.19 ± 8.78) μSv/h; There was a statistical difference in radiation levels between detection points in the PET/CT workplace (F = 56.72, P < 0.05), in which the ambient dose equivalent rates of the administration window (nurse operating position) was 14.28 to 21.55 μSv/h, with an average of (16.55 ± 3.87) μSv/h; In 16 nuclear medical workplaces, the average surface contamination level met the standard requirements. Two (12.50%) of the staff's work clothes and eight (50.00%) of their hands surface contamination level exceeded the standard in terms of surface contamination. The external exposure individual dose level of 77 nuclear medical staff was (1.11 ± 0.65) mSv. None of the 77 radiation workers were found apparent skin abnormalities, but 12 (15.58%) had some abnormalities in tissues and organs that were more sensitive to ionizing radiation. There were no significant differences found in the ocular lens abnormalities and chromosome abnormalities of the persons with exposure time of more than 20 years compared with other age groups. Conclusion: Radiation protection in the nuclear medicine workplace under investigation was in good condition, but the staff's own protection needs to be strengthened; Further attention should be paid to the occupational health management of nuclear medical personnel. (authors)

[en] Objective: To investigate and analyze the occupational external exposure personal dose in shijiazhuang nuclear medical personnel, to master the actuality of external exposure in nuclear medicine personnel and provide the basis on strengthening the radiological protection of nuclear medical personnel. Methods: Personal dose equivalent H_p(10) was monitored in nuclear medical personnel through the thermoluminescence dose measurement the relevant data was analyzed. Results: There was statistical difference in external exposure dose between the groups that had put thermoluminescence dosimeter outside and inside of the lead clothes (t = 2.36, P < 0.05), external exposure dose had been reduced 18% for those using lead clothes. There were statistical differences in external exposure dose levels on different posts of nuclear medicine personnel (F = 4.01, P < 0.05). The dose per person in the cwi group was the lowest (1.66 ± 0.34), and the dose per person in the nurse group was the highest (2.71 ± 2.30); when using lead clothing, there was no difference between the cwi group and the nurse group (F = 1.07, P > 1.07). Conclusion: lead rubber can play a part in protecting nuclear medicine personnel; The radiological protection of nuclear medicine nurses and technicians should be taken seriously. (authors)

[en] Highlights: • A set of CeO_x@C-TiO₂ visible light responsive novel photocatalysts were synthesized. • 10% CeO_x@C-TiO₂ exhibited high photocatalytic efficiency for TC mineralization. • The hydroxyl and superoxide anion radicals played superior role in TC mineralization. • The feasible photocatalytic mechanism of 10% CeO_x@C-TiO₂ sample was investigated. • The photocatalyst is stable for continuous run for low TC concentration. The overuse of antibiotics triggered a serious environmental crisis, stimulating the development of feasible technologies for removing antibiotics from wastewater. Herein, a set of CeO_x@C-TiO₂ composites with varying amounts of CeO_x from 1% to 15% were synthesized and applied for the photodegradation of tetracycline (TC) for the first time. It was found that the composites exhibited excellent performance for TC removal by degradation and mineralization under visible-light irradiation. The uniform distribution of CeO_x nanoparticles in C-TiO₂ permitted the surface contact of particles, enhancing their visible light absorption with a reduced band gap of 2.39 eV and electron-transfer efficiency through the formation of heterojunctions. The amount of CeO_x played a predominant role in the photocatalytic properties. The 10% composite exhibited high removal rates of 99.1%, 98.2%, and 83.5% for 10, 20, and 40 mg/L TC, respectively. Characterization experiments proved that Ce mainly existed in its +3 and +4 valence states in the composites. The interchange of these two valence states accelerated the transfer of electrons and promoted the production of superoxide anion radicals and hydroxyl radicals responsible for TC degradation. These findings provide valuable guidelines for exploiting high-performance MOF-derived photocatalysts for the abatement of contaminants.

[en] Highlights: • The mechanism of dynamic precipitation within the shear band is firstly analyzed. • The mechanism of grain refinement within the shear band is discussed. • Findings provide new dates about dynamic transformation for aging alloy. -- Abstract: The phase transformation during high strain rate deformation was generally considered to be martensite transformation and diffusion transformation could not happen due to the limited time for diffusion. The motivation of this paper is to study the mechanism of dynamic precipitation of second phases and the grain refinement in the adiabatic shear band (ASB) of solid-solution treated ZK60 magnesium alloy. The specimens of the solid-solution treated ZK60 magnesium alloy were loaded by means of radial collapse of thick-walled cylinders (TWC). The microstructural characteristics within ASB of sample were studied by optical metallography (OM) and transmission electron microscopy (TEM). OM observations showed that ASB with a width of ~3 μm was formed after dynamic loading. It was found for the first time that fine second phase particles were precipitated in the central region of ASB. The second phases were instantaneously precipitated under the combined effect of a large number of crystal defects and adiabatic temperature rise during the adiabatic shearing process. TEM observation revealed that elongated grains appeared at the inner edge of ASB, while fine equiaxed grains were formed in the central region of ASB. The fine equiaxed grains were the result of rotational dynamic recrystallization of subgrains induced by a combined effect of shear stress and the adiabatic temperature rise. The findings provided new data about dynamic transformation for aging alloy.

[en] A series of novel single-component color tunable phosphors KAlGeO₄:Bi³⁺,Eu³⁺ were synthesized by high-temperature solid state reaction. The crystal structure and electronic structure were analyzed by Rietveld refinement method and density functional theory (DFT) calculations, from which the lattice parameters and bandgap energy were determined. Photoluminescence properties, fluorescence decay and the energy transfer process have been investigated systematically. Under 320 nm excitation, KAlGeO₄:Bi³⁺,Eu³⁺ shows both blue emission of Bi³⁺ and red emission of Eu³⁺, originating from the allowed ³P₁–¹S₀ transition of Bi³⁺ and the ⁵D₀–⁷F_J transitions of Eu³⁺, respectively. By adjusting the mole ratio of Bi³⁺ to Eu³⁺, the color of KAGO:Bi³⁺,Eu³⁺ can be tuned from blue to orange-red. The energy transfer mechanism was determined, and the energy transfer efficiency from Bi³⁺ to Eu³⁺ increased linearly with the increasing of Eu³⁺ concentration. Moreover, KAGO:Bi³⁺,Eu³⁺ has good thermal quenching properties.

[en] Microstructure evolution in adiabatic shear band (ASB) in the peak aged ZK60 magnesium alloy cylindrical tube specimen after explosive radial compression was systematically investigated. High strain rate compression tests were performed by means of the radial collapse of thick-walled cylinder technique to achieve nominal strain rates of about 10⁴ s⁻¹. The TEM results indicate that the elongated grains and deformed twins are the major characteristics in the boundary of the shear band. The central region in ASB was found to consists of ultrafine and equiaxed grains with a typical size of 100 nm. And it was found that precipitates within ASB were significantly reduced, namely the precipitates instantaneous dissolution during adiabatic shearing. It is proposed that fine equiaxed grains within ASB are the result of rotational dynamic recrystallization during localization. The free energy difference between the precipitates and matrix provided a thermodynamic condition for the dissolution of precipitates. Diffusion rate increased due to high strain rate, high shear stress (large strain) and adiabatic temperature rise, which caused instantaneous dissolution of precipitates.