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Cardiovascular disease has become one of the leading causes of death in China, accounting for 45.5% of all deaths in rural areas and 43.16% in urban areas. Hence, its early diagnosis is important. With the development of intravascular imaging technology, the intravascular ultrasound (IVUS) is widely used. The available commercial mechanical rotary side-looking IVUS (SL-IVUS) transducers are driven by external motors that use long flexible shafts to transmit the rotation. However, when the transducer passes through a long-curved blood vessel, it easily causes the nonuniform rotation distortion (NURD) of the image. A catheter which contains a distal motor and sodium chloride (NaCl) solution is presented in this study as an attempt to solve such issues. The NaCl solution is used to connect the transducer and micromotor so that the motor can directly drive the transducer to rotate and acquire the information of the blood vessel. The results showed that the center frequency and −6-dB fraction bandwidth of the single element were 47 MHz and 98%, respectively. The SL-IVUS catheter consists of a distal motor, with speed stability and high resolution, and has the potential to diagnose cardiovascular disease. This novel structure can decrease the dimension at the top of the catheter and reduce the risks of clinical diagnosis. [ABSTRACT FROM AUTHOR]

The article discusses the use of coupled model to investigate surface water and groundwater management that could improve environment-related problems at Shiyang River basin in China. The model assesses the quality of water quality and enhances affected water resources due to water-related human activities. The coupled model includes integrated rule-based lumped surface water model and distributed three-dimensional groundwater flow model.

This article discusses the interactions between groundwater, springs, and the Heihe River in China. The authors developed a simulation model of the regional water flow in the multilayered aquifer system. The model shows that the hydraulic connection between the aquifers and the river changes from coupling to decoupling at some reaches. The authors suggest that there is a need to reduce groundwater withdrawal and to rationalize the use of both surface water and groundwater in order to maintain sustainable development.

The duration of geological events has distinct implications for geological processes. Secondary ion mass spectrometry (SIMS) U–Pb dating of inherited zircon cores and metamorphic rims is the most common method used to determine the age of a protolith, and the timing and duration of metamorphism. This study investigates the age deviation induced by overlapping pre-sputtered areas during SIMS zircon core–rim U–Pb dating, using eclogite and country-rock granitic gneiss samples from the Shuanghe area in the Dabie Orogen, China. First, we analyzed only the zircon core or rim on each grain. Concordant ages of igneous zircon cores in two orthogneisses are 744 ± 10 and 768 ± 7 Ma, demonstrating that their protoliths were Neoproterozoic igneous rocks. The metamorphic zircon rims in the two granitic gneisses yielded a consistent weighted-mean 206Pb/238U age of 216 ± 2 Ma (2 SE; n = 12 and 17). Zircon grains in the studied eclogite are all metamorphic and yielded a weighted-mean 206Pb/238U age of 224 ± 2 Ma (2 SE; n = 21). The different metamorphic ages of the eclogite and orthogneisses suggest that they might be juxtaposed by later tectonic events. After being repolished, zircon grains with apparent core–rim structures from the two granitic gneisses were re-analyzed in the cores and rims of each grain. Due to the small size of the zircon grains, the pre-sputtered areas of the two spots in each zircon overlapped. Compared with the analyses in the first session, the overlapping pre-sputtered areas affacted apparent dates for zircon rims by −8.2% to +13.2%. The age deviations of the second analyses correlate with the relative position of the overlaps. The apparent 206Pb/238U dates are younger when delta X < 0 (i.e., the X coordinate of the second analysis is smaller than the first analysis), while the apparent 206Pb/238U dates are older when delta X > 0. This study proves that erroneous SIMS U–Pb dates can be produced when dating metamorphic zircon rims after analyses of the cores with overlapping pre-sputtered areas. It will lead to an apparently longer and incorrect duration of a metamorphic event. • Overlapping pre-sputtered areas of adjacent spots significantly affect SIMS U-Pb age. • The apparent 206Pb/238U dates deviate by −8.2% to +13.2% while pre-sputtered domains overlap in lateral direction. • The value of DTCA-X has potential to correct the deviated 206Pb/238U age. • The age of metamorphism of the eclogite lens is different from the country-rock orthogneiss. [ABSTRACT FROM AUTHOR]

Background: Little is known about the knowledge and attitudes towards human papillomavirus (HPV) and its vaccines among adolescents in mainland China. Also, limited information has been available on how to improve their knowledge and willingness towards HPV and its vaccines to ensure a successful vaccination program in the future., Methods: This was a school-based interventional follow-up study. One urban and one rural junior middle school in Chengdu were selected by convenience sampling. At baseline, half of the grade one students were randomly selected as controls and the rest were interventions. A set of self-administered questionnaires on HPV and its vaccines were completed by both groups at baseline. After that, only the intervention group received a PowerPoint-oriented health education and finished the post-education questionnaires. One year later, both groups completed the same questionnaires as the follow-up survey., Results: In total, 1675 students finished the pre-intervention questionnaires; 751 were from the control group and 924 were from the intervention group. Among them, only 34.3% had heard of cervical cancer/genital warts, while only 15.1% of them had ever heard of HPV. However, 55.2% of students showed their willingness to be vaccinated even before any intervention. Seven variables were found to be associated with the willingness to be vaccinated at baseline. Immediately after the intervention, 88.4% of students were willing to vaccinate themselves. After 1 year, the effectiveness of intervention remained but decreased. Compared with the control group, the intervention group was more aware about cervical cancer, HPV and its vaccines with statistical significance. However, the level of HPV knowledge and willingness to be vaccinated among the intervention group had significantly decreased compared with that immediately after the intervention (P < 0.001)., Conclusions: The baseline level of knowledge on HPV, its vaccines, and cervical cancer was very low among junior middle school students in Chengdu, China. However, the willingness to be vaccinated seemed positive. School-based health education is effective and appropriate in increasing the awareness of HPV and willingness towards its vaccines. Regular health education on HPV and cervical cancer prevention at a shorter interval should be guaranteed to ensure continuous effectiveness.