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ObjectiveTo analyze the pollution status and exposure risks of heavy metals by three edible traditional Chinese herbal medicine， such as ganoderma lucidum， dendrobium officinale， and American ginseng in Guangdong Province.MethodsFresh and dried raw materials of Ganoderma lucidum， Dendrobium officinale， and Panax quinquefolium， as well as food products， were collected from 10 cities in Guangdong Province. Among them， 33 samples were collected in Guangzhou， and 30 samples were collected in each of the other 9 cities. The concentrations of lead， cadmium， total mercury， and total arsenic in the three substances were determined and analyzed using inductively coupled plasma method. Based on the point assessment model， we calculated the average concentrations of heavy metals in fresh （converted at a dry rate） and dried raw materials， and evaluated the health risks according to the medicinal and dietary consumption patterns.ResultsAs the dietary consumption pattern， the exposure levels were higher than the medical consumption pattern， and the cadmium exposure levels of Ganoderma lucidum， Dendrobium officinale and American ginseng accounted for 8.51%， 8.72% and 8.56% of PTMI. The exposure levels of total mercury accounted for 3.51%， 0.91%， and 1.08% of PTWI. The MOE values of lead exposure were 11.56， 7.14， and 20.94， respectively， while the MOE values of total arsenic exposure were 68.34， 102.39， and 152.28， respectively. After considering the dietary exposure pathway， the risks of heavy metal caused by the three edible traditional Chinese herbal medicine were still within an acceptable range.ConclusionResidents in Guangdong Province had a lower risks of exposure to lead， cadmium， total mercury， and total arsenic through the dietary exposure pattern of ganoderma lucidum， dendrobium officinale， and panax quinquefolium.

Portulaca oleracea is widely distributed around the world and has a long history of dual use in the fields of medicine and food. Its chemical constituents include flavonoids, polyphenols, terpenoids, sterols, coumarins, alkaloids, polysaccharides and organic acids, which make it have excellent antibacterial and antioxidant effects. More and more research has reported the antibacterial activity of Portulaca oleracea, which is significantly different on different bacteria, but a systematic review is lacking. In this paper, we summarize recent progress in research on the chemical composition, antimicrobial effect and mechanism of Portulaca oleracea in order to provide as a reference for the bioefficacy research, clinical application and product development of Portulaca oleracea.

ObjectiveTo reveal the effects of specific factors on aflatoxin B1 （AFB1） contamination in peanut oil and the status of AFB1 contamination in peanut oil in Guangdong Province from 2017 to 2018 was taken as an example.MethodsA total of 637 peanut oil samples were collected from 21 cities in Guangdong Province from 2017 to 2018， and their labels were recorded. The content of AFB1 in peanut oil was detected according to “GB 5009.22—2016 Determination of aflatoxin group B and group G in foods”. The temperature data of manufacturing place was obtained from ECMWF Reanalysis v5 database （ERA5） and the average temperature of the month before production was calculated， and the correlation between temperature and AFB1 content was then analyzed.ResultsThe total detection rate of AFB1 in peanut oil samples was 65.3% with 24.6% over-standard rate. There was no over-standard sample in the standardized packages， while the bulk samples had a higher over-standard level rate and the median content of AFB1 was significantly higher than that in the standardized package samples. Among several meteorological factors， average temperature of the month before peanut oil production had a strong relevance to the over-standard rate and content of AFB1 in the samples. The median content of AFB1 in bulk peanut oil samples with average temperature of pre-production above 25 ℃ was about 3.5 times that of the samples with average temperature below 22 ℃. However， other meteorological factors showed no correlation with AFB1 content in peanut oil.ConclusionAFB1 in bulk peanut oil samples in Guangdong Province from 2017 to 2018 has a high over-standard rate， and the average temperature of pre-production is a key factor affecting the content of AFB1. Therefore， the government should raise the awareness of the production environment and production process to ensure the quality of bulk peanut oil and reduce the risk of AFB1 exposure and other risks.

We propose a model for computed tomography (CT) image reconstruction and segmentation simultaneously, which can be applied to single-energy spectral (traditional) CT (SECT) and dual-energy spectral CT (DECT) image reconstruction. It is difficult to solve the model due to the large scale of imaging system and the nonlinear forward projection of DECT. In order to deal with the model, a superiorized iteration algorithm is presented, which handles image segmentation and image reconstruction alternately. The two steps are combined by a superiorized perturbation step. The convergence of the iteration procedure is proved for SECT image reconstruction theoretically, and the convergence for DECT image reconstruction is investigated numerically. Experiments on various data are conducted. Comparisons with existing methods show that the proposed method is better quantitatively and visually. [ABSTRACT FROM AUTHOR]