First report of the maize cyst nematode Heterodera zeae in Sichuan Province of Southwest China.

Maize is the largest crop planted in China. Nine species of cyst nematodes have been reported to affect maize production. Heterodera zeae, H. avenae and Punctodera chalcoensis can cause significant maize yield losses annually (Luc et al. 2005). In 1971, the maize cyst nematode H. zeae was first detected in Rajasthan, India (Koshy et al. 1971). Subsequently, it has been reported in many other countries such as the United States, Greece, Pakistan, and Egypt. In China, H. zeae was first identified in the maize fields of Laibin City, Guangxi Zhuang Autonomous Region (Wu et al., 2017). Cui et al. (2020) identified H. zeae in a maize field of Yuzhou City, Henan Province of Central China in 2018. From 2018 to 2022, a survey of cyst-forming nematodes was conducted in Southwest China. Fifteen soil samples of about 500 g each were collected from Luding County, Ganzi Prefecture of Sichuan Province. No major aboveground symptoms were shown on maize, but a few females were observed on the roots of maize in one field. The cysts and second-stage juveniles (J2s) were collected from each soil sample using Cobb's screening gravity method. A total of 8.50±2.0 cysts per 100 ml of soil on the average were observed in the field. A thin subcrystalline layer was discernible only in young cysts. Morphological and molecular studies of cysts and J2s indicated that the nematodes were identified to be H. zeae in a maize-field. Morphologically, the cysts were in a lemon shape, light brown or pearly white in color. The vulval cone was prominent. Fenestra ambifenestrate, and semifenestra were separated by a fairly wide vulval bridge, fenestral length and width were variable, and the cyst wall was shown in a zigzag pattern. The J2s' body was in a vermiform, tapering at both ends, with a hyaline tail. Stylet was strongly developed with round or slightly anteriorly directed knobs. Morphological measurements of the cysts (n = 9) determined that the mean body length was 417.2 µm (403.6 to 439.4 µm), body width was 429.7 µm (397.6 to 456.9µm); length-width ratio was 1.4 (0.75 to 3); fenestra length was 525.3 µm (498.5 to 570.7 µm); and the mean semifenestra width was 458.6 µm (403.6 to 546.3 µm). Morphometric measurements of second-stage juveniles (n = 20) showed a body length of 419.7µm (355.8 to 492.5 µm); a stylet length of 20.8 µm (19.51 to 23.3µm); a tail length of 41.5 µm (20 to 49.4 µm); and a hyaline tail length of 20.7 µm (16.6 to 24 µm). The main morphological characteristics and measured values were basically consistent with those described by Cui et al. (2022), and all of which were similar to those of H. zeae. Amplification of DNA from random single cysts (n = 5) was conducted using the protocol described by Cui et al. (2022). The rDNA-internal transcribed spacer (ITS) was amplified and sequenced using a pair of universal primers TW81 (5'-GTTTCCGTAGGTGAA CCTGC-3') and AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3'). The ITS sequences were deposited at GenBank with the accession number OR811029.1. Alignments of sequences showed an identity of 98% with H. zeae sequences from China (OP692769.2, MW785772.1) and the USA (GU145616.1), which were confirmed using a pair of species-specific primers HzF1 (5'-GGGGAGGTGAATGTGGG-3') and HzR1 (5'-CCTTTGGCAATCGGTGA-3') of H. zeae with a targeted PCR fragment of 393 bp (Cui et al. 2022). Pathogenicity was conducted and confirmed by infection and reproduction on maize. Seeds (cv. Zhengda 619) were sown in three pots that contained 150 ml of a sterile soil mixture (loamy soil: sand=1:1), and 5 cysts (103 eggs/cyst on the average) were inoculated in each pot at 25/30°C, under a 12-h dark/12-h light condition (Cui et al. 2023). Fifteen days after sowing, third- and fourth-stage juveniles were observed in the rootstained with acid fuchsin, and a total of 32 cysts per maize plant on the average were collected at 40 days after sowing. The new cysts' morphological and molecular characteristics were identical to the cysts from the original soil samples. To the best of our knowledge, this is the first report of H. zeae as a pathogen on maize in Sichuan Province, Southwest China. Our findings will be useful for management and further research of maize cyst nematodes.

Identification and Biological Characterization of a New Cyst Nematode, Heterodera glycines sbsp.n. tabacum, Parasitizing Tobacco in China.

In an investigation of diseases from plant-parasitizing nematodes in Henan Province, a cyst nematode was found on tobacco roots and in rhizosphere soil. We identified this strain as a new cyst nematode subspecies, Heterodera glycines sbsp.n. tabacum. The cysts and second-stage juveniles (J2s) parasitizing Henan tobacco were larger than those of H. glycines. A single 345-bp fragment was amplified from H. glycines sbsp.n. tabacum, whereas the 345- and 181-bp fragments were amplified from the soybean cyst nematode. Thus, H. glycines sbsp.n. tabacum was distinct from H. glycines. There were base transversions at 504 sites and base transitions at 560, 858, 920, and 921 sites in the rDNA-ITS sequences of H. glycines sbsp.n. tabacum compared with H. glycines, and there were base transitions at 41, 275, 278, and 380 sites in the mtDNA-COI sequences. In the phylogenetic tree based on the rDNA-ITS and mtDNA-COI regions, H. glycines sbsp.n. tabacum was clustered on a single branch. Based on the randomly amplified polymorphic DNA (RAPD) technique, sequence characterized amplified region (SCAR)-PCR primers were designed. A single 1,113-bp fragment was amplified by specific primers (HtF1/HtR1) from H. glycines sbsp.n. tabacum, while no fragments were obtained from H. glycines. The H. glycines sbsp.n. tabacum can infect soybean plants but cannot complete its life cycle on soybean. Eleven tested tobacco cultivars were infected, with an average reproduction factor (Rf) of 9.74 and a maximum of 64.2 in 'K326'. The cumulative egg hatching rate of H. glycines sbsp.n. tabacum in the presence of tobacco root exudates was 42.6% at 32 days posthatching, which was significantly greater than that in the presence of soybean root exudates (30.3%) or sterile water (33.1%). In summary, the cyst nematode population parasitizing Henan tobacco was identified as a new subspecies, H. glycines sbsp.n. tabacum.

Ecotoxicological risk of antibiotics and their mixtures to aquatic biota with the DGT technique in sediments.

Antibiotics are emerging contaminants and widely used in human healthcare, livestock, and aquaculture. The toxicity posed by antibiotics and their mixtures in sediments depends on their bioavailability. Now, the bioavailability of organic materials can be determined accurately by the diffusive gradients in thin films (DGT) technique. This technique was used for the first time ever in this study to evaluate in detail the integral toxicity of antibiotics in sediments to aquatic biota. Zhelin Bay was selected as a case study, because it is the largest mariculture area in eastern Guangdong, South China. Two antibiotics, chlortetracycline (CTC) (A) and sulfachlorpyridazine (SCP), were detected at average concentrations of 2.83 and 1.14 ng/ml, respectively. The other fifteen antibiotics were undetectable. The single risk assessment based on the risk quotient (RQ) of CTC and SCP shows that a relatively low risk has occurred. After this careful assessment of probabilistic ecotoxicological risks, the combined toxicity of antibiotic mixtures (CTC and SCP) clearly indicates that the toxicity probability of surface sediments to aquatic organisms was relatively low (0.23%).

First record of cyst nematode (Heterodera filipjevi) on winter wheat from Shanxi Province in North China.

Heterodera avenae, H. filipjevi, and H. laptipons are considered to be the major cyst nematode pathogens affecting most cereals and causing severe crop losses (Smiley and Yan 2015). In China, H. filipjevi was first recorded in Xuchang, Henan Province (Peng et al. 2010). Recently, H. filipjevi has been found in Anhui, Hebei, Shandong and Xinjiang provinces of China (Cui et al. 2021). To further understand the latest occurrence and distribution of H. filipjevi in China, a survey of cyst nematodes was conducted in the wheat planting area of Shanxi Province of North China from June 2018 to November 2020. White female cysts (5.8 ± 2.99 cysts per plant) were found on wheat roots in the sandy soil, and wheat was displaying symptoms of dwarfing, yellowing, and had few tillers in Licheng of Changzhi (N36°32´010´´, E113°27´039´´; N36°29´050´´, E113°23´023´´; N36°29´035´´, E113°22´020´´) and Zezhou of Jincheng (N35°33´057´´, E112°56´020´´) in Shanxi Province, and second-stage juveniles (J2s) were obtained from 13 soil samples using the sieving-decanting method. Four of the 13 samples were identified as H. filipjevi on the basis of morphological and molecular studies of female cysts and J2s. Morphologically, the cysts were lemon shaped and featured a pronounced vulval cone. The color ranged from light to dark brown. The white female shell was covered with a white crystalline layer. The vulval cone was bifenestrate with horseshoe-shaped bullae numerous and distinct, and a strongly developed underbridge. The main measurements (mean ± SD, range) of cysts (n = 13) were as follows: body length including neck 780.5 ± 53.9 µm (692 to 843 µm); body width 527.3 ± 55.5 µm (435 to 620 µm); length/width ratio 1.50 ± 0.21 (1.20 to 1.93); fenestra length 55.5 ± 4.1 µm (49 to 61 µm); fenestra width 24.8 ± 2.2 µm (21.1 to 28.8 µm); vulval slit length 9.0 ± 0.7 µm (7.8 to 9.6 µm); and underbridge length 66.8 ± 5.0 µm (61 to 77 µm). The measurements of J2s (n = 13) were as follows: body length 554.4 ± 23.4 µm (520to 587 µm); stylet length 22.7 ± 0.7 µm (21.5 to 23.8 µm); tail length 61.0 ± 5.5 µm (51.2 to 68.9 µm); and hyaline tail terminus length 37.3 ± 2.7 µm (33.4 to 42.3 µm). These morphological measurements are within the range characteristic of H. filipjevi (Peng et al. 2010). Genomic DNA was extracted from individual cyst (n = 6) and the rDNA internal transcribed spacer (ITS) sequence was amplified using the universal primers TW81 and AB28 (Joyce et al. 1994). The PCR test for each sample was repeated five times. The obtained ITS sequences (GenBank accession No. OQ421499 to OQ421502, 1054 bp) showed more than 99.5% similarity to those of H. filipjevi from the United States (GU079654 and KP878490), Turkey (KR704304 and KR704292), and China (MW789611, KY448473 and KT314234). The results were confirmed again by the species-specific primers HfF1 and HfR1of H. filipjevi and the target PCR fragments of 646 bp were obtained (Peng et al. 2013). The pathogenicity of H. filipjevi was verified by infesting winter wheat (Triticum aestivum 'Wenmai 19') and studying nematode developmentand reproduction with growth chamber (Cui et al. 2015). Eggs were hatched at 14-16°C, and freshly hatched J2s were used to inoculate wheat plants when the roots were approximately 1-centimeter long. Fifteen wheat plants were inoculated with 200 J2s, and three wheat plants without J2s were set as controls (Cui et al. 2021). Parasitic J2s and third- and fourth-stage juveniles were found in roots stained with acid fuchsin at 5, 15, and 25 days after inoculation (DAI), adult females were detected at 50 DAI, and a mean of 23.7 cysts per pot were extracted at 70 DAI (Cui et al. 2015). The morphological and molecular characteristics of the new cysts were identical to those of the H. filipjevi cysts from the original field samples, and no cysts formed in the control groups. Wheat is the main food and economic crop in Shanxi, and H. filipjevi, a potential threat to cereal crop production in Shanxi, should arouse sufficient attention. H. filipjevi is major cyst nematode pathogens of wheat and shows high prevalence in China. The loss of wheat production due to H. filipjevi is as high as 32.3% when the initial density ≥ 64 eggs/mL in soil (Li 2018). To the best of our knowledge, this is the first report of H. filipjevi in Shanxi Province of North China.

First record of Aphelenchoides besseyi on foxtail millet (Setaria italica) in Henan Province of China.

Aphelenchoides besseyi is one of the important plant-parasitic nematodes on rice, reducing approximate 10-20% of the rice yield annually (Jones et al. 2013). Foxtail millet (Setaria italica) has been a major cereal crop in Northern China, especially in the semi-arid areas of this region, for thousands of years. In August of 2019 and 2020, a survey of nematodes on autumn grain crops was performed each year. One foxtail millet field (N34° 58' 027″ and E113° 39' 059″) in Yuanyang County of Henan Province caught our attention. Some upper leaves showed chlorosis without or with necrotic tips, and flag leaves presented crinkling and distortion, stalks were colored, earheads were vertical, glumes were brown or light black and open, and grains became thin. A total of ten samples were collected, and the nematodes were isolated from the spike pieces by shallow plate method and counted under a stereomicroscope. The average number of nematodes per earhead of foxtail millet counted up to 1738.75 ± 107.72. Morphologically, females were slender with a short stylet, an oval metacorpus with a distinct valve, a labial region slightly wider than the first body annulus and a conoid tail with a terminus bearing a star-shaped mucro with four pointed processes. The females were characterized as follows (mean ± SD; n=20): body length (L) = 668.92 ± 12.73 µm (647.38 to 689.70 µm); maximum body width (W) = 14.35 ± 1.11 µm (12.12 to 16.88 µm); L/W = 46.83 ± 2.94 (40.44 to 50.03); tail length = 38.93 ± 3.48 µm (33.41 to 45.92 µm); L/tail length = 17.31 ± 1.44 (14.47 to 19.62); and stylet length (ST) = 11.57 ± 0.57 µm (10.77 to 12.34 µm). The males had three pairs of ventrosubmedian papillae with the first one adanal, spicula curved with a slight basal process, terminus bearing four mucrones arranged variably, and the whole worm was in 'J' shape. The males could be described as follows (mean ± SD, n = 20): L = 606.66 ± 10.70 µm (586.49 to 626.37 µm); W = 13.95 ± 0.60 µm (12.71 to 14.94 µm); L/W = 43.55 ± 1.69 (40.73 to 46.43); tail length = 35.54 ± 1.93 µm (31.41 to 38.18 µm); L/tail length = 17.07 ± 0.79 (16.05 to 18.67); ST = 11.53 ± 0.56 µm (1061 to 12.76 µm). All the key morphometrics were consistent with those of A. besseyi reported from Brazil (Favoreto et al. 2018) and China (Lin et al. 2004; Ou et al. 2014). The amplifications of rDNA internal transcribed spacer (ITS) fragments generated a PCR fragment of 830 bp from a single nematode, using the primers set TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3') (Joyce et al. 1994). Five independent PCR experiments were conducted, and all the PCR products were purified and sequenced. Nucleotide sequence of ITS-rDNA was deposited in GenBank with Accession Number OK090549.1. The obtained ITS region sequence was more than 99% identical to those of A. besseyi reported from China (MW216945.1) and India (JF826518.1, JF826519.1 and JF826517.1). These ITS sequence results further supported that the isolated nematodes were A. besseyi. Subsequently, the species-specific primers of A. besseyi (BSF, 5'-TCGATGAAGAACGCAGTGAATT-3' and BSR, 5'-AGATCAAAAGCCAATCGAATCAT-3') were used for confirmation by PCR (Cui et al. 2010). An expected PCR fragment of 312 bp was obtained, which was consistent with those of A. besseyi reported previously. The pathogenicity of identified A. besseyi was confirmed by infection of foxtail millet (Setaria italica cv. 'Yugu33'). Foxtail millet budding seeds were sown in the pots contained 150 mL of sterile soil mixture. In two weeks, 10 seedlings were inoculated with 100 A. besseyi each, and 4 plants were non-inoculated as the control. The foxtail millet seedlings were grown in a plant-growth chamber at 25/30°C under 12 h dark/12 h light. On the average, 73.3 and 138.2 of A. besseyi were isolated from each plant at 15 and 40 days post inoculation, respectively. Both the morphological and molecular characteristics were identical with those nematodes obtained from the original samples. All the upper leaves of the inoculated plants showed chlorosis and necrosis, symptoms that were similar to those observed in the field, and neither symptom developed on the non-inoculated control plants, nor were nematodes re-isolated from the control plants. To the best of our knowledge, this is the first record of A. besseyi on foxtail millet in Henan Province of North China. Henan is one of the most important grain-producing areas in China, and A. besseyi is an important domestic quarantine nematode, which may become a severe threat to cereal production in Henan Province. Our findings will be very beneficial for A. besseyi management and further research on foxtail millet in Henan Province of North China.

First report of Heterodera filipjevi on winter wheat from Hebei Province in North China.

Three of the cereal cyst nematodes, Heterodera avenae, H. filipjevi and H. latipons are considered to be the most economically important cyst nematodes that affect cultivated cereals around the world. H. filipjevi was first detected in China from Xuchang, Henan Province in 2010 (Peng et al. 2010) and now has been recorded in the Central China of Henan, Shandong and Anhui provinces and the Northwest China of Xinjiang Uygur Autonomous Region (Cui et al. 2020). In June 2019, 42 samples consisting of roots and soil were collected from winter wheat fields in Hebei Province of North China. Cysts were detected in 37 soil samples with a mean of 6.4 ± 1.67 cysts per 100 ml of soil. Cysts and second-stage juveniles (J2s) were extracted from root and soil following Cobb's sieving gravity method. Morphological and molecular studies of J2s and cysts confirmed its identity with H. filipjevi in 5 samples from Handan (N36°10'052" and E114°35'056"; N36°37'054" and E114°22'052"), Xingtai (N36°53'060" and E114°30'011") and Shijiazhuang (N 37°26'048" and E 116°05'039") in Hebei Province, China. Morphologically, the cysts are lemon-shaped, light or dark brown in color. The vulval cone is bifenestrate with horseshoe-shaped semifenestrae, strongly globular bullae, and well-developed underbridge. Measurements (mean +_ sd (range)) of cysts (n=10), body length not including neck is 743.0 ± 36.1 µm (665 - 780 µm), body width is 559.0 ± 50.0 µm (455 - 639 µm), length / width ratio is 1.33 ± 0.07 (1.20 - 1.46); neck length is 99.3 ± 8.8 µm (85 - 122 µm); fenestrae length is 56.8 ± 5.0 µm (49 - 65 µm) and width is 25.5 ± 1.8 µm (21.1 - 27.8 µm); underbridge length is 84.0 ± 8.1 µm (62 - 93 µm); and vulval slit length is 8.6 ± 0.5 µm (7.2 - 9.1 µm). Measurements of J2s (n = 12), body length is 541 ± 11.4 µm (490 - 578 µm); stylet length is 22.3 ± 0.5 µm (22.0 - 25.0 µm) with anchor-shaped basal knobs; tail length is 57.7 ± 3.7 µm (52.7 - 65.2 µm), and hyaline tail terminal length is 36.5 ± 2.8 µm (32 - 39.8 µm). The tail had a sharp terminus. Morphology of the cysts and J2s were consistent with the record of H. filipjevi (Peng et al. 2010; Subbotin et al. 2010). The amplifications of rDNA-internal transcribed spacer (ITS) fragments were generated with a PCR fragment of 1054 bp from single cysts of each population, using primers TW81 and AB28 (Joyce et al. 1994). The PCR tests for each sample were repeated five times. The PCR product was purified and sequenced. All nucleotide sequences of ITS-rDNA were submitted to GenBank under accession numbers MW282843-6. Sequences from the ITS region were more than 99.5% identical to those of H. filipjevi from Egypt (KF225725), Turkey (KR704308, KR704293 and MN848333) and China (KT314234, MT254744 and KY448473). These results from ITS supported its identity as H. filipjevi. The results were also confirmed by species specific sequence characterized amplified region primers of H. filipjevi (Peng et al. 2013). Pathogenicity of the H. filipjevi was confirmed by infection of winter wheat (Triticum aestivum L cv. 'Aikang58') and examination of the nematode development and reproduction. Wheat seeds were germinated in petri dishes and then transplanted into five polyvinyl chloride tubs (3 cm in diameter, 25 cm in length) that contained 150 cm3 of a sterile soil mixture (loamy soil: sand = 1:1), each with 5 cysts (mean of 252.0 eggs/cyst). Plants were grown in an artificial climate box for one week at 14/18°C, two weeks at 16/20°C, five weeks at 18/25°C and two weeks at 22/30°C, under 8 h of darkness/16 h light and normal culturing practices (Cui et al. 2015). The parasitic J2s, third and fourth-stage juveniles, and adult females were observed in roots stained with acid fuchsin at 10, 20, 30, and 50 days after inoculation (DAI), and an average of 32.0 cysts per tubes were extracted 70 DAI. The new cyst' morphological and molecular characteristics were identical to the H. filipjevi cysts from the original soil samples. Three other tubes without cysts were set as control and there were no newly formed cysts. Heterodera avenae and H. filipjevi had been detected in a total of 16 wheat-producing provinces in China, which resulted in losses of 1.9 billion CNY year-1 (Cui et al. 2015). To our knowledge, this is the first report of H. filipjevi in Hebei Province of North China. Cereal cyst nematodes are easily transferred to non-infested areas by many avenues, resulting in increased species and pathotype complexity (Cui et al. 2020). Once H. filipjevi continues to spread in main wheat producing area of China, it could become be a new threat to cereals production. It is time to take effective control methods to prevent H. filipjevi further dispersal, especially through the farming machinery transmission. Hebei Province is one of the most important major grain-producing areas, our findings will be very beneficial for H. filipjevi management and further research on winter wheat in Hebei Province, North China.

The Clinical Efficacy of N-Acetylcysteine in the Treatment of ST Segment Elevation Myocardial Infarction.

The aim of this study was to evaluate the clinical efficacy of N-acetylcysteine (NAC) in the treatment of ST segment elevation myocardial infarction (STEMI).PubMed, EMBASE, Cochrane Library, and Web of Science were searched systematically from the establishment of the database to June 2020. Two researchers independently completed literature screening and data extraction and conducted a meta-analysis.Nine articles including 1419 patients were enrolled. Meta-analysis showed that all-cause mortality [RR = 0.56, 95%CI (0.33, 0.93), P = 0.02], occurrence of major adverse cardiovascular events (MACE) [RR = 0.63, 95%CI (0.47, 0.85), P = 0.002], and myocardial enzyme hs-TnT level [SMD = -0.42, 95%CI (-0.71, -0.13), P = 0.005] were significantly lower in patients with STEMI treated with NAC than those in the control group. There was no significant difference between the NAC group and the control group in new congestive heart failure [RR = 0.94, 95%CI (0.48, 1.82), P = 0.84], ejection fraction [MD = 2.00, 95%CI (-0.59, 4.60), P = 0.13], and CK-MB [SMD = -0.18, 95%CI (-0.47, 0.11), P = 0.23]. There was no significant difference in the occurrence of adverse reactions between the NAC group and the control group [RR = 1.04, 95%CI (0.57-1.89), P = 0.90].NAC can reduce the all-cause mortality and MACE cases of STEMI.

First record of Heterodera elachista infecting rice in Henan Province of central China.

From June 2018 to November 2019, a survey for cyst-forming nematodes was conducted in rice fields in Henan Province of central China. Cysts were recovered from two rice fields (N32° 14' 048″8 and E115° 4' 008″) at Huangchuan County, leading to more intensive sampling. A further 25 soil samples were then collected with a valve bag from each of these two locations. Cysts and second-stage juveniles (J2) were recovered from roots and soil following Cobb's gravity sieving method. Live cysts were detected in all soil samples with a mean of 6.7±1.5 cysts per 100 ml of soil. Morphologically, the cysts were spherical to lemon-shaped, light to dark brown in color with subcrystalline layer. The vulval cone was well developed, cone terminus with a few large, peripheral, dark brown bullae lacking finger-like projections, and the ambifenestrae were almost rounded with two semifenestrae; width and length of the semifenestrae were similar. The vulval bridge was narrow, with a medium sized underbridge. Cyst measurements (n = 8) determined a mean body length of 431.1 ± 47.23 (351.0 - 516.0) µm, body width 304.3 ± 47.40 (240.0 - 381.0) µm; body length to width ratio 1.42 ± 0.10 (1.2 to 1.6); fenestrae length 39.4 ± 7.06 (26.0 - 47.0) µm; fenestrae width 36.5 ± 5.96 (25.0 - 43.0) µm; vulva slit length 37.1 ± 3.62 (30.0 - 42.0) µm; and the mean underbridge length 75.0 ± 3.39 (70.0 - 81.0) µm. Morphometric J2 measurements (n = 10) included a body length of 432.3 ± 53.26 (379.0 - 512.0) µm; stylet length 20.8 ± 1.87 (18.0 - 24) µm with rounded knobs; tail length 63.1 ± 7.92 (52.0 - 75.0) µm with a hyaline terminal tail length of 35.8 ± 6.14 (28.0 - 45.0) µm. The key morphometrics of this isolate were intermediate to those of the Japanese isolates (Nobbs et al. 1992.) and Chinese isolates (Ding et al. 2012), and other morphological character values were within the range of those reported for Heterodera elachista (Nobbs et al. 1992; Tanha Maafi et al. 2003). Amplification of DNA from single cysts (n = 7) was conducted using the protocol described by Ding et al. (2012). rDNA - ITS sequences were amplified with the universal primers TW81 and AB28 (Joyce et al. 1994). The PCR product was purified and sequenced. The ITS sequences were submitted to GenBank under accession numbers MT579616. Comparisons showed a sequence identity of more than 99.9% for H. elachista sequence MN720080 from Korea and 99.5% for H. elachista sequences JN864884 and JN202916 from China. Species identification was also confirmed using sequence characterized amplified region (SCAR) methods with H. elachista-specific primers He-F/He-R (Qi, 2012). An expected PCR fragment of approximately 434 bp was obtained, which was consistent with those previously reported for H. elachista. Pathogenicity was confirmed by infection and reproduction on rice (Oryza sativa cv. 'Nipponbare'). Seeds were sown into three tubes containing 150 ml of a sterile soil mixture (loamy soil: sand = 1:1), each with 5 cysts (mean of 185 eggs/cyst) and cultivated in an artificial climate box at 25/30°C, under a 12-h dark/12-h light cycle. Three other tubes without cysts were set as control. Two weeks after sowing, stunting and reduction of leaf length were observed and third- and fourth-stage juveniles were observed in roots stained with acid fuchsin. On average, 142 cysts per 150 ml soil were recovered at 5 weeks after sowing. The newly formed cysts corresponded morphologically and molecularly to the cysts from the original soil samples. The globally recognized and economically important rice-damaging cyst nematodes include H. oryzae, H. oryzicola, H. elachista, H. sacchari and H. graminophila (Zhuo et al. 2014). Ohshima (1974) first reported H. elachista, which was originally recorded as H. oryzae in Japan by Luc and Brizuela (1961). H. elachista was then detected from a rice field at Mazandaran Province in Iran (Tanha Maafi et al., 2003), and in upland rice fields in Hunan (Ding et al., 2012) and Guangxi, China (Zhuo et al. 2014). To the best of our knowledge, this is the first report of H. elachista as a pathogen on rice in Henan Province, in central China. According to our field observations, H. elachista was much more serious in direct-seeded rice field than in the transplanted rice fields. H. elachista was also reported attacking corn (Xiao et al., 2019). Henan is the most important corn-producing province in China, thus H. elachista is a potential threat to corn production in Henan. Our findings will be very beneficial for H. elachista management and further research on direct-seeded rice and corn in Henan Province, central China.

Pathotype, Resistance Classification, and Seed-Coating Control of Heterodera avenae and H. filipjevi in the North China Plain.

Heterodera avenae and H. filipjevi are cereal cyst nematodes (CCNs) that infect cereals in 16 provinces of China. CCN populations from Xuchang, Tangyin, Qihe, and Juye were tested using 23 barley, oat, and wheat entries of the International Test Assortment for Defining Cereal Cyst Nematode Pathotypes. H. avenae populations from Tangyin, Qihe, and Juye were classified as pathotype Ha91, and H. filipjevi from Xuchang was classified as a new pathotype similar to pathotype West. Among 42 other winter wheat cultivars, 29 and 30 were differentially susceptible, 13 and 12 were differentially resistant to H. avenae and H. filipjevi, respectively. Three entries were resistant to both species, and three other entries were resistant to H. avenae and moderately resistant to H. filipjevi. Coating wheat seed with abamectin + isopycnic imidacloprid or methylene (bis) thiocyanate + thiamethoxam reduced the number of H. avenae and H. filipjevi cysts by 46 to 56%, increased wheat yield by 9 to 27%, and improved net income by 660 to 2,640 Chinese Yuan ha-1, respectively. Resistant wheat cultivars are scarce in China, and seed coating is considered the most suitable method for controlling CCNs in the North China Plain, where crop rotation cannot be practiced.

Nanoassembly of probucol enables novel therapeutic efficacy in the suppression of lung metastasis of breast cancer.

Metastasis is one of the major obstacles hindering the success of cancer therapy. The directed nanoassembly of probucol results in the "DNP" system, which greatly improves the oral delivery of probucol and subsequently leads to a novel therapeutic efficacy of probucol in the suppression of lung metastasis of breast cancer. DNP is formed by employing the intermolecular hydrophobic interactions between probucol and polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether (also known as Triton X-100). After oral administration, the probucol concentration in the intestines is surprisingly about 200 times higher if it is applied as DNP rather than free probucol; it can be absorbed into intestinal enterocytes via clathrin-mediated endocytosis and transported into the systemic circulation through the lymphatic pathway. Moreover, the oral bioavailability of probucol is significantly higher-13.55 times higher-when applied as DNP in place of free probucol. The drug concentration in major organs is also significantly increased. The in vitro measurements show that the migration and invasion abilities of 4T1 cells are obviously inhibited by DNP. In particular, in an orthotopic metastatic breast cancer model, the notable suppression of lung metastasis from DNP is observed, but no effect is seen from the free-probucol suspension. As a result, the directed drug nanoassembly may open a new route for enhancing oral drug delivery and enable new therapeutic abilities for probucol against cancer metastasis.

Directed self-assembled nanoparticles of probucol improve oral delivery: fabrication, performance and correlation.

PURPOSE: We are reporting on the development of a unique drug delivery platform by directed self-assembly technique to improve the oral delivery of hydrophobic drugs. METHODS: Herein, a series of probucol directed self-assembled nanoparticles (PDN) were developed with two components of probucol and surfactant such as Tween 20, Tween 80, D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS) and HS-15, which was respectively named as T20-PDN, T80-PDN, TP-PDN and HS-PDN. The formation of various PDNs was determined by in vitro characterization and the physicochemical properties of these PDNs were determined. Moreover, the performance of PDN in enhancing the oral delivery and possible correlation between the in vitro properties and in vivo performances were investigated. RESULTS: PDN was homogenous nanometer-sized particles with negative surface charge. The cellular uptake of probucol in Caco-2 cell monolayer was respectively increased 1.15, 1.82, 1.59 and 5.31-fold by these PDN. In particular, the oral bioavailability of these PDN was significantly improved 3.0, 4.1, 5.4 and 10.4 folds compared with the free drug suspension. The enhanced cellular uptake and oral bioavailability were correlated with the characters of involved surfactants and the particle size of PDN. CONCLUSIONS: Thereby, the directed self-assembled nanoparticles could provide a new strategy for enhancing the oral delivery of hydrophobic drugs.

Probabilistic risk assessment of microplastics on aquatic biota in coastal sediments.

As an emerging form of pollution, microplastic contamination of the coastal ecosystems is one of the world's most pressing environmental concerns. Coastal sediments have been polluted to varying degrees by microplastics, and their ubiquitous presence in sediments poses a threat to marine organisms. However, there is currently no ecological risk assessment of microplastics on aquatic biota in sediments. This study, for the first time, established a new procedure to evaluate the toxicity of microplastics on aquatic biota in sediments, based on the probabilistic risk assessment (PRA) concept. The choice of Zhelin Bay as the case study site was based on its severe pollution status. The average content of microplastics in the sediments of Zhelin Bay was 2054.17 items kg-1 dry weight, and these microplastics consisted of 46 different species. Microplastics in sediments exist in five different forms, with the film form being the main composition, and the majority of microplastics have particle sizes ranging from 100 to 500 µm. Correlation analysis (CA) reveals significant negative correlations between microplastic abundance, and Al2O3 and SiO2. The toxicity of microplastics, based on the PRA concept, suggests that Zhelin Bay surface sediments had a low probability (3.43%) of toxic effects on aquatic biota.

Cu-II-directed self-assembly of fullerenols to ameliorate copper stress in maize seedlings.

Widespread use of copper-based agrochemical may cause copper excessive accumulation in agricultural soil to seriously threaten crop production. Recently, fullerenols are playing important roles in helping crops build resistance to abiotic stresses by giving ingenious and successful resolutions. However, there is a lack of knowledge on their beneficial effects in crops under stresses induced by heavy metals. Herein, the visual observation of Cu2+-mediated assembly of fullerenols via electrostatic and coordination actions was carried out in vitro, showing that water-soluble nanocomplexes and water-insoluble cross-linking nanohybrids were selectively fabricated by precisely adjusting feeding ratios of fullerenols and CuSO4. Furthermore, maize simultaneous exposure of fullerenols and CuSO4 solutions was tested to investigate the comparative effects of seed germination and seedling growth relative to exposure of CuSO4 alone. Under moderate Cu2+ stresses (40 and 80 µM), fullerenols significantly mitigated the detrimental effects of seedlings, including phenotype, root and shoot elongation, biomass accumulation, antioxidant capacity, and Cu2+ uptake and copper transporter-related gene expressions in roots. Under 160 µM of Cu2+ as a stressor, fullerenols also accelerated germination of Cu2+-stressed seeds eventually up to the level of the control. Summarily, fullerenols can enhance tolerance of Cu2+-stressed maize mainly due to direct detoxification through fullerenol-Cu2+ interactions restraining the Cu2+ intake into roots and reducing free Cu2+ content in vivo, as well as fullerenol-maize interactions to enhance resistance by maintaining balance of reactive oxygen species and optimizing the excretion and transport of Cu2+. This will unveil valuable insights into the beneficial roles of fullerenols and its mechanism mode in alleviating heavy metal stress on crop plants.

Environmental and dietary exposure to 24 polycyclic aromatic hydrocarbons in a typical Chinese coking plant.

Polycyclic aromatic hydrocarbons (PAHs), known for their health risks, are prevalent in the environment, with the coking industry being a major source of their emissions. To bridge the knowledge gap concerning the relationship between environmental and dietary PAH exposure, we explore this complex interplay by investigating the dietary exposure characteristics of 24 PAHs within a typical Chinese coking plant and their association with environmental pollution. Our research revealed Nap and Fle as primary dietary contaminants, emphasizing the significant influence of soil and atmospheric pollution on PAH exposure. We subjected our data to non-metric multidimensional scaling (NMDS), Spearman correlation analysis, Lasso regression, and Weighted Quantile Sum (WQS) regression to delve into this multifaceted phenomenon. NMDS reveals that dietary PAH exposure, especially within the high molecular weight (HMW) group, is common both within and around the coking plant. This suggests that meals prepared within the plant may be contaminated, posing health risks to coking plant workers. Furthermore, our assessment of dietary exposure risk highlights Nap and Fle as the primary dietary contaminants, with BaP and DahA raising concerns due to their higher carcinogenic potential. Our findings indicate that dietary exposure often exceeds acceptable limits, particularly for coking plant workers. Correlation analyses uncover the dominant roles of soil and atmospheric pollution in shaping dietary PAH exposure. Soil contamination significantly impacts specific PAHs, while atmospheric pollution contributes to others. Additionally, WQS regression emphasizes the substantial influence of soil and drinking water on dietary PAHs. In summary, our study sheds light on the dietary exposure characteristics of PAHs in a typical Chinese coking plant and their intricate interplay with environmental factors. These findings underscore the need for comprehensive strategies to mitigate PAH exposure so as to safeguard both human health and the environment in affected regions.

Reversal of multidrug resistance by mitochondrial targeted self-assembled nanocarrier based on stearylamine.

Multidrug resistance (MDR) remains one of the major challenges for successful chemotherapy. Herein, we tried to develope a mitochondria targeted teniposide loaded self-assembled nanocarrier based on stearylamine (SA-TSN) to reverse MDR of breast cancer. SA-TSN was nanometer-sized spherical particles (31.59 ± 3.43 nm) with a high encapsulation efficiency (99.25 ± 0.21%). The MDR in MCF-7/ADR cells was obviously reduced by SA-TSN, which mainly attributed to the markedly reduced expression of P-gp, increased percentages in G2 phase, selectively accumulation in mitochondria, decrease of mitochondrial membrane potential, and greatly improved apoptosis. The plasma concentration of teniposide was greatly improved by SA-TSN, and the intravenously administered SA-TSN could accumulate in the tumor site and penetrate into the inner site of tumor in MCF-7/ADR induced xenografts. In particular, the in vivo tumor inhibitory efficacy of SA-TSN in MCF-7/ADR induced models was more effective than that of teniposide loaded self-assembled nanocarrier without stearylamine (TSN) and teniposide solution (TS), which verified the effectiveness of SA-TSN in reversal of MDR. Thereby, SA-TSN has potential to circumvent the MDR for the chemotherapy of breast cancer.

The anthropogenic effects on organic matter in sediment core based on Bayesian mixing model: a case study of Daya Bay.

Sediment is an important carrier of evidence about environmental evolution which receives huge volumes of organic material originated from both anthropogenic and natural sources. In this study, based on sedimentary chronology, the vertical trends of particle size distribution, total organic carbon (TOC), total nitrogen (TN), and their stable isotopes (δ13C, δ15N) in the sediment core of the nuclear power sea in southwest Daya Bay were analyzed, and the distribution characteristics and contribution ratios of different sources of organic matter in the sedimentary environment over the past 70 years were resolved using a Bayesian mixing model (MixSIAR). TOC, TN, δ13C, and δ15N ranged from 0.89 to 1.56%, 0.09 to 0.2%, - 22.3 to - 20.6‰, and 4.38 to 6.51‰, respectively. The organic matter in the sediment is controlled by a mixture of terrestrial input and marine autochthonous, the proportion of organic matter from terrestrial sources increases, while that from marine sources decreases in the sediment core, which persists from 1960 to 2000, yet organic matter from marine sources still dominates. The first signs of increased primary productivity occurred in 1960, and it was primarily due to agricultural activity. After the 1980s, the rapid increase in population around Daya Bay, the construction of nuclear power plants, the rise of aquaculture, and the quick expansion of industrial bases were all major factors that changed the ecological environment of Daya Bay.

Nonmetric multidimensional scaling and probabilistic ecological risk assessment of trace metals in surface sediments of Daya Bay (China) using diffusive gradients in thin films.

This research is one main objective to assess combined toxicity of trace metal mixtures in aquatic biota in coastal sediments. Coastal sediments around the world are a major reservoir of trace metals from industrial wastewater discharge. Our case study site, Daya Bay in southern China, was selected because it has been under severe man-made impacts. Diffusive gradients in thin films (DGT) technique has proven to be a good method for measuring the bioavailability of trace metals. The bioavailability and distribution of trace metals in surface sediments were investigated along with their possible biological risks. The average bioavailable (DGT-labile) concentrations (µg/L) were 0.44 (V), 0.51 (Cr), 52.49 (Mn), 0.10 (Co), 1.36 (Ni), 0.74 (Cu), 14.53 (Zn), 0.97 (As), 0.14 (Se), 6.73 (Mo), 0.17 (Cd), 0.27 (Sb), 0.10 (W), and 1.32 (Pb). Nonmetric multidimensional scaling (NMS) is a robust multivariate ordination method that makes no assumptions about the distribution of the underlying data. NMS was used to explore that DGT-labile concentrations of trace metals were influenced by sediment properties. NMS results indicated that most DGT- labile trace metals influenced by sediment properties. Risk assessment of single trace metal toxicity revealed that risk quotient (RQ) values for Mn, Cu, Zn and Pb significantly exceeded 1, demonstrating that the toxic effects of these trace metals should be not ignored. The probabilistic ecological risk assessment for integral toxicity of one mixture of 14 trace metals revealed that Daya Bay surface sediments had a low probability (9.04 %) of adverse effects on aquatic biota.

Bioavailability and health risk assessment of Zn and Cd in edible tissues of two typical shellfish species using in vitro gastrointestinal digestion.

Dynamic extraction of edible tissues of Jinjiang oyster (Crassostrea rivularis) and Flower clam (Paphia undulata) was conducted using a fully biomimetic digestion (in vitro) method. The impact of different cooking methods on the bioavailability of Zn and Cd in the edible shellfish tissues was analyzed, and the human health risk of Zn and Cd was evaluated. The results show that the gastric biomimetic extractions of Zn and Cd in unheated samples of C. rivularis and P. undulata were higher than those in the intestinal biomimetic extraction. The extraction patterns of cooked samples were consistent with those of raw samples. The bioavailability of Zn and Cd in cooked samples of C. rivularis was 94.9% and 82.5%, respectively, indicating increased Zn bioavailability but decreased Cd bioavailability compared to the raw samples. The bioavailability of Zn and Cd in cooked samples of P. undulata was 85.1% and 83.0%, respectively, both of which decreased compared to the raw samples. Consumption of C. rivularis can provide 21.0% to 34.2% of the daily required Zn intake, while consumption of P. undulata can provide 3.8% to 6.4%. The intake of Cd from both shellfish species is below the monthly tolerable intake recommended by FAO/WHO. Consuming cooked C. rivularis can increase the intake of Zn and decrease the intake of Cd.

Bioenrichment preference and human risk assessment of arsenic and metals in wild marine organisms from Dapeng (Mirs) Bay, South China Sea.

Bioenrichment preference of arsenic and metals in wild marine organisms has been scarcely considered. Twenty species including fishes, cephalopods, crustaceans, and bivalve mollusks were collected from Dapeng (Mis) Bay and analyzed for arsenic and metals. Through this study, we had obtained the following four main conclusions: (1) average concentrations of arsenic and metals (µg/kg, wet weight) in the aquatic organism samples were 48.7 for Cr, 1762.0 for Mn, 20,632.8 for Fe, 33.0 for Co, 119.5 for Ni, 3184.7 for Cu, 12,040.5 for Zn, 389.0 for As, 189.1 for Se, 144.4 for Cd, 15.0 for Hg, and 55.3 for Pb; (2) factor analysis (FA) revealed that the studied twenty species exhibited three types of arsenic and metal bioenrichment preference;(3) non-carcinogenic health risk assessment indicated insignificant health effects from marine organism consumption; (4) carcinogenic health risk assessment revealed an unacceptable risk from consumption of nine species, seven of which were crustaceans.

Rare earth elements in sediments from a representative Chinese mariculture bay: Characterization, DGT-based bioaccessibility, and probabilistic ecological risk.

Rare earth elements (REEs) are emerging contaminants due to their worldwide exploitation in the high-technology sector. Aquaculture systems, particularly those located within coastal areas, are fragile ecosystems due to anthropogenic impacts regarding urban and aquaculture activities. However, to date, there are no reports on the combined toxicity of rare earth element (REE) mixtures on aquatic biota in sediments from coastal aquaculture systems. In this study, the combined toxicity of REE mixtures based on probabilistic risk assessment indicated that the surface sediments of Zhelin Bay had a 1.86% probability of toxic effects on aquatic biota. The average value of total REEs (TREEs) was 297.37 µg/g, with light REEs representing the major part. A factor analysis (FA)-geographic information system (GIS)-based approach coupled with correlation analysis (CA) revealed that the REEs are derived from anthropogenic sources through fluvial processes.