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Background: Little is known about the global distribution and environmental drivers of key microbial functional traits such as antibiotic resistance genes (ARGs). Soils are one of Earth's largest reservoirs of ARGs, which are integral for soil microbial competition, and have potential implications for plant and human health. Yet, their diversity and global patterns remain poorly described. Here, we analyzed 285 ARGs in soils from 1012 sites across all continents and created the first global atlas with the distributions of topsoil ARGs., Results: We show that ARGs peaked in high latitude cold and boreal forests. Climatic seasonality and mobile genetic elements, associated with the transmission of antibiotic resistance, were also key drivers of their global distribution. Dominant ARGs were mainly related to multidrug resistance genes and efflux pump machineries. We further pinpointed the global hotspots of the diversity and proportions of soil ARGs., Conclusions: Together, our work provides the foundation for a better understanding of the ecology and global distribution of the environmental soil antibiotic resistome. Video Abstract., (© 2022. The Author(s).)

Soils are the foundation of all terrestrial ecosystems 1 . However, unlike for plants and animals, a global assessment of hotspots for soil nature conservation is still lacking 2 . This hampers our ability to establish nature conservation priorities for the multiple dimensions that support the soil system: from soil biodiversity to ecosystem services. Here, to identify global hotspots for soil nature conservation, we performed a global field survey that includes observations of biodiversity (archaea, bacteria, fungi, protists and invertebrates) and functions (critical for six ecosystem services) in 615 composite samples of topsoil from a standardized survey in all continents. We found that each of the different ecological dimensions of soils-that is, species richness (alpha diversity, measured as amplicon sequence variants), community dissimilarity and ecosystem services-peaked in contrasting regions of the planet, and were associated with different environmental factors. Temperate ecosystems showed the highest species richness, whereas community dissimilarity peaked in the tropics, and colder high-latitudinal ecosystems were identified as hotspots of ecosystem services. These findings highlight the complexities that are involved in simultaneously protecting multiple ecological dimensions of soil. We further show that most of these hotspots are not adequately covered by protected areas (more than 70%), and are vulnerable in the context of several scenarios of global change. Our global estimation of priorities for soil nature conservation highlights the importance of accounting for the multidimensionality of soil biodiversity and ecosystem services to conserve soils for future generations., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Soil pollution is an important stressor affecting biodiversity and ecosystem functioning. However, we lack a holistic understanding of how soil microbial communities respond to heavy metal pollution in agricultural ecosystems. Here, we explored the distribution patterns and inter-kingdom interactions of entire soil microbiome (including bacteria, fungi, and protists) in 47 paired paddy and upland fields along a gradient of legacy mercury (Hg) pollution. We found that the richness and composition of protistan community had stronger responses to Hg pollution than those of bacterial and fungal communities in both paddy and upland soils. Mercury polluted soils harbored less protistan phototrophs but more protistan consumers. We further revealed that long-term Hg pollution greatly increased network complexity of protistan community than that of bacterial and fungal communities, as well as intensified the interactions between protists and the other microorganisms. Moreover, our results consistently indicated that protistan communities had stronger responses to long-term Hg pollution than bacterial and fungal communities in agricultural soils based on structural equation models and random forest analyses. Our study highlights that soil protists can be used as bioindicators of Hg pollution, with important implications for the assessment of contaminated farmlands and the sustainable management of agricultural ecosystems., (© 2022. The Author(s).)

The Yangtze River Economic Belt is one of the areas with rapid economic development in China, although the intensive industrial activities have aggravated the emissions of soil pollutants in this area. Industrial activities are important sources of soil heavy metal contamination; however, the spatial distribution and main emission sources of soil heavy metal contamination in industrial regions of the economic belt remain unclear. Here, we collected data on the concentrations of eight heavy metals (Cd, Cr, Cu, Pb, Ni, Hg, As, and Zn) in the surface soils of 193 industrial regions covering 11 provinces and cities of the Yangtze River Economic Belt from China National Knowledge Infrastructure (CNKI), Web of Science, and other public databases. On this basis, we analyzed the spatial distribution characteristics of heavy metals and the contamination characteristics of typical industries. The results showed that the heavy metal contamination in agricultural land was more serious than that in industrial land. A total of 58.49%, 39.53%, and 22.64% of the agricultural land, respectively, contained levels of Cd, Zn, and Pb that exceeded the screening values of the Soil Environmental Quality Control Standard for Soil Pollution Risk of Agricultural Land (GB 15618-2018). The results of geo-accumulation index analysis showed that the contamination degree of the eight heavy metals was in the order of Cd (2.52)>Hg (1.17)>Pb (1.00)>Zn (0.90)>Cu (0.72)>As (0.02)>Cr (-0.40)>Ni(-0.48). As for the spatial distribution, Hg, Cd, As, Cu, Pb, and Zn were the main pollutants in the upstream and middle reaches of the industrial regions, whereas As, Cd, and Hg were the main pollutants in the downstream industrial regions. Different types of industry caused different types of contamination. Mining industries caused the most serious soil contamination, the main pollutants of which were Hg and Cd, followed by Cu, Pb, and Zn. Furthermore, metal processing industries mainly caused Cd and Pb contamination. The surrounding soils of chemical industries were contamination-free or only slightly polluted by the eight heavy metals, whereas petroleum processing industries mainly caused Cd contamination. Our study provides important theoretical basis for the future prevention and control of soil heavy metal contamination in industrial regions of the Yangtze River Economic Belt.

Trait-based approaches provide a candidate framework for linking soil microbial community to ecosystem processes, yet how the trade-offs in different microbial traits regulate the community-level metabolic efficiency remains unknown. Herein we assessed the roles of the microbial taxa with particular trait strategies in mediating soil microbial metabolic efficiency along an altitude gradient on the Tibetan Plateau. Results showed that soil microbial metabolic efficiency declined with increasing altitude, as indicated by the increasing metabolic quotient (microbial respiration per unit biomass, qCO 2 ) and decreasing carbon use efficiency (CUE). Both qCO 2 and CUE were predominantly predicted by microbial physiological and taxonomic attributes after considering key environmental factors including soil pH, substrate quantity and quality. Specifically, the reduced metabolic efficiency was associated with higher investment into nutrient (particularly for phosphorus) acquisitions via enzymes. Furthermore, we identified key microbial assemblies selected by harsh environments (low substrate quality and temperature) as important predictors of metabolic efficiency. These results suggest that particular microbial assemblies adapted to nutrient limited and cold habitats, but at the expense of lower metabolic efficient at higher altitude. Our findings provide a candidate mechanism underlying community-level metabolic efficiency, which has important implications for microbial-mediated processes such as carbon dynamics under global climate changes., (© 2021. The Author(s).)

Objective To explore the effect of air pollution on the number of emergency room visits for respiratory diseases in residents at different ages and its seasonal changes in Lanzhou,so as to provide a scientific basis for the early prevention of respiratory diseases in Lanzhou. Methods The daily number of emergency room visits for respiratory diseases in three class A hospitals in Lanzhou from January 1,2013 to December 31,2017,as well as the air pollutants and meteorological data of Lanzhou in the same period,was collected.After controlling the confounding factors including long-term trend of time,meteorological factors and day-of-week effect using a generalized additive model,we analyzed the relationships between air pollutants and the daily number of emergency room visits for respiratory diseases,and explored whether there was a lag effect of air pollutants.Results From 2013 to 2017,the emergency room visits for respiratory diseases in Lanzhou had a total number of 124 871,with an average of 69(1-367)visits per day.The single pollutant model showed that among the six conventional air pollutants monitored in Lanzhou,PM 2.5 ,PM 10 ,NO 2 ,SO 2 and O 3 8h had a lag effect on the number of emergency room visits for respiratory diseases.For every 10 μg/m 3 increase in the concentration of PM 2.5 (lag02: t =4.792, P =0.001), PM 10 (lag2: t =3.421, P <0.001), NO 2 (lag6: t =3.654, P =0.003), SO 2 (lag06: t =4.712, P <0.001)and O 3 8h (lag07: t =3.021, P =0.012), the number of emergency room visits for respiratory diseases increased by 0.900%(95% CI :0.573%-1.249%), 0.083%(95% CI :0.012%-0.153%), 1.293%(95% CI :0.867%-1.720%), 3.851%(95% CI :2.675%-5.041%)and 0.737%(95% CI :0.129%-1.348%), respectively.For every 1 mg/m 3 increase in the concentration of CO(lag0: t =3.564, P <0.001),the number of emergency room visits for respiratory diseases increased by 2.556% (95% CI : 1.493%-3.629%). In gender stratification, PM 2.5 (male: t =3.124, P =0.019;female: t =3.418, P =0.007), PM 10 (male: t =2.980, P =0.160;female: t =2.997, P =0.013)and CO(male: t =4.117, P =0.001;female: t =4.629, P <0.001)in winter had stronger effects on the emergency room visits for respiratory diseases in females than that in males, while the effects of NO 2 (male: t =3.020, P =0.107;female: t =3.006, P =0.128), SO 2 (male: t =4.101, P <0.001;female: t =3.820, P <0.001)and O 3 8h(male: t =3.660, P =0.022;female: t =3.517, P =0.018)in winter showed an opposite trend.In age stratification, the increase in the daily average concentration of PM 2.5 (0-14 years old: t =3.520, P =0.008), PM 10 (0-14 years old: t =3.840, P <0.001), SO 2 (0-14 years old: t =4.570, P <0.001), CO(0-14 years old: t =4.102, P =0.002)in winter would increase the emergency visits for respiratory diseases in the 0-14-year-old population.The daily average concentration of O 3 8h(0-14 years old: t =4.210, P <0.001;15-64 years old: t =3.807, P =0.001)in summer only affected the visits of the 0-14-year-old and the 15-64-year-old populations, and the air pollutants had no significant effect on the visits of those≥65 years old.The double pollutant model analysis revealed that after introducing 5 other pollutants respectively, PM 2.5 , PM 10 , NO 2 , SO 2 and O 3 8h significantly increased the emergency room visits for respiratory diseases, and CO had a more obvious effect than that predicted with the single pollutant model. Conclusion The rises in the concentrations of six air pollutants in Lanzhou will increase the emergency room visits for respiratory diseases, and the patterns vary with different genders, ages and seasons.

Heavy metal(loid)s exert selective pressure on microbial communities and evolution of metal resistance determinants. Despite increasing knowledge concerning the impact of metal pollution on microbial community and ecological function, it is still a challenge to identify a consistent pattern of microbial community composition along gradients of elevated metal(loid)s in natural environments. Further, our current knowledge of the microbial metal resistome at the community level has been lagging behind compared to the state-of-the-art genetic profiling of bacterial metal resistance mechanisms in a pure culture system. This review provides an overview of the core metal resistant microbiome, development of metal resistance strategies, and potential factors driving the diversity and distribution of metal resistance determinants in natural environments. The impacts of biotic factors regulating the bacterial metal resistome are highlighted. We finally discuss the advances in multiple technologies, research challenges, and future directions to better understand the interface of the environmental microbiome with the metal resistome. This review aims to highlight the diversity and wide distribution of heavy metal(loid)s and their corresponding resistance determinants, helping to better understand the resistance strategy at the community level., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 The Author(s).)

As pollution in farmland has a toxic effect on the growth of crops, which reduces their yield and quality. The effects of exogenous spermidine (Spd) on rice seed germination and seedling growth under As 5+ stress were studied. The results showed that exogenous Spd could promote the germination of rice seeds under As 5+ stress, improve the germination potential and germination rate of seeds, and promote the growth of seedling roots. The addition of Spd could increase the activity of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) of rice seedlings and roots under As 5+ stress, and reduce the content of malondialdehyde (MDA) in rice buds and roots. When As 5+ concentration was 25 μmol·L -1 , adding 500 μmol·L -1 and 1000 μmol·L -1 Spd, MDA content in rice roots was decreased by 12.3% and 31.3% and CAT activity of rice shoots was increased by 105.1% and 101.4%, and CAT activity of rice roots was increased by 29.9% and 57.1%, respectively. The addition of Spd also affected the uptake and accumulation of As in rice. When the concentration of As 5+ was 25 μmol·L -1 , adding 500 μmol·L -1 and 1000 μmol·L -1 Spd, the concentration of As in rice shoots decreased by 69.4% and 75.1%, and As concentration in rice roots decreased by 7.6% and 24.4%, respectively. Spd could therefore effectively alleviate the toxic effect of As 5+ on rice.

Despite distinct roles of soil microbes in regulating carbon (C) respiration in diverse environments, it remains unclear whether microbial taxonomic and functional attributes can consistently predict soil C emissions across contrasting ecosystems. Here, we conducted a large-scale sampling event across two contrasting croplands (rice and wheat-corn crop rotation) to identify specific soil microbial phylotypes and functional genes associated with soil respiration rates. The results of structural equation modeling indicated that bacterial community composition had a strong link with C respiration rates in the two contrasting cropland types; however, this link was weaker for fungal communities. More importantly, we found that the relative abundances of bacterial Solirubrobacterales&#95;480-2, Myxococcales&#95;mle1-27 and fungal Westerdykella had consistently negative correlation with respiration rates across paddy and upland soils. We also identified taxa that are significantly correlated to C respiration in the paddy (e.g. Methylocaldum) and upland soils (e.g. Kribbella), respectively. Further, we found multiple associations between functional genes involved in microbial C metabolism and soil respiration rates. Our findings provide novel insights into understanding microbial predictors of soil CO 2 emissions in diverse croplands, which have important implications for improving C emission predictions in terrestrial ecosystems., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Intestinal neuronal dysplasia (IND) is a common malformation of the enteric nervous system. Diagnosis requires a full-thickness colonic specimen and an experienced pathologist, emphasizing the need for noninvasive analytical methods. Recently, the methylation level of the Sox10 promoter has been found to be critical for enteric nervous system development. However, whether it can be used for diagnostic purposes in IND is unclear., Methods: Blood and colon specimens were collected from 32 patients with IND, 60 patients with Hirschsprung disease (HD), and 60 controls. Sox10 promoter methylation in the blood and the Sox10 expression level in the colon were determined, and their correlation was analyzed. The diagnostic efficacy of blood Sox10 promoter methylation was analyzed by receiver operating characteristic curve., Results: The blood level of Sox10 promoter methylation at the 32nd locus was 100% (90%-100%; 95% confidence interval [CI], 92.29%-96.37%) in control, 90% (80%-90%; 95% CI, 82.84%-87.83%) in HD, and 60% (50%-80%; 95% CI, 57.12%-69.76%) in IND specimens. Sox10 promoter methylation in the peripheral blood was negatively correlated with Sox10 expression in the colon, which was low in control, moderate in HD, and high in IND specimens (r = -0.89). The area under the curve of Sox10 promoter methylation in the diagnosis of IND was 0.94 (95% CI, 0.874-1.000, P = 0.000), with a cutoff value of 85% (sensitivity, 90.6%; specificity, 95.0%). By applying a cutoff value of 65%, promoter methylation was more indicative of IND than HD., Discussion: The analysis of Sox10 promoter methylation in the peripheral blood can be used as a noninvasive method for IND diagnosis.

Bioremediation programs of cadmium (Cd) by microorganisms have being proposed, but the underlying mechanism of the remediation ion remains unexplored. Here, the sorption efficiency and subcellular fraction distribution of Cd in three selected microbial species were investigated. Our results showed that both species of the microorganisms and initial Cd concentrations strongly affected the Cd sorption capacity. In the three microbial species, the Cd removal efficiency increased with decreased Cd concentrations. Specifically, Hansenula anomala removed the highest Cd ions in low concentration of 0.05 mg L -1 ; while in medium concentration of 0.5 mg L -1 and high concentration of 5 mg L -1 , Bacillus subtilis removed the highest Cd ions. The subcellular fractionation allocation showed that Cd was mainly allocated on cell wall (mantle and inner wall) in Pseudomonas stutzeri and B. subtilis, while cell cytomembrane accumulated similar amount of Cd compared to the cell wall of H. anomala at concentration of 0.5 mg L -1 . Meanwhile, the Cd distributions on cell subcellular fractionation of the three species changed along the contact times, suggesting varied migration models during the biosorption process. Moreover, the functional groups involved in biosorption differed among the species based on Fourier Transform Infrared (FTIR) analysis. Our results have important implications for developing and improving Cd remediation by microorganisms, which is a low-cost and environmentally friendly bioremediation strategy of Cd pollution in environments., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Methylmercury (MeHg) is the most toxic organic matter of all mercury (Hg) compounds. Its toxicity is far higher than that of inorganic Hg. Methylmercury can enter the human body through food, threatening human health. Based on the Nanweng River National Nature Reserve in the Greater Xing'an Mountains, the differences in the distribution of MeHg in soil samples collected from four types of wetlands, including medium swamp, low swamp, island forest, and forest soil, and the effect of the soil properties on the MeHg content were investigated in this study. The results show that:① the trends of the total Hg and MeHg levels are inconsistent. The order of the mean total Hg content is island forest (138.76 mg·kg -1 ±101.97 mg·kg -1 ) > forest soil (117.57 mg·kg -1 ±32.44 mg·kg -1 ) > low swamp (71.8 mg·kg -1 ±1.42 mg·kg -1 ) > median swamp (65.11 mg·kg -1 ±26.69 mg·kg -1 ), while the mean MeHg content is in the order of island forest (1.14 μg·kg -1 ±1.15 μg·kg -1 ) > medium swamp (0.87 μg·kg -1 ±1.06 μg·kg -1 ) > low swamp (0.28 μg·kg -1 ±0.06 μg·kg -1 ) > forest soil (0.1 μg·kg -1 ±0.05 μg·kg -1 ); ② the contents of MeHg in the island forest and medium swamp were relatively high and fluctuated dramatically, whereas the contents of MeHg in the low swamp and forest soil were lower and showed little change between each sampling point; ③ the longer the marsh wetland formation was, the higher was the MeHg content, that is, median swamp (0.87 μg·kg -1 ±1.06 μg·kg -1 ) > low swamp (0.28 μg·kg -1 ±0.06 μg·kg -1 ); the soil pH was positively correlated with MeHg ( P <0.05); in the medium swamp area, the content of MeHg was positively related to the water content (WC), organic matter (OM%), carbon (C%), and total mercury (THg; P <0.05); in the island forest areas, the MeHg content showed a linear relationship with the soil pH and NH 4 + -N ( P <0.05). This study reveals the distribution characteristics of MeHg and its influencing factors for different wetland ecosystems, providing data supporting the comprehensive evaluation of MeHg accumulation in wetland ecosystems.

The legacy impacts of past climates on the current distribution of soil microbial communities are largely unknown. Here, we use data from more than 1,000 sites from five separate global and regional datasets to identify the importance of palaeoclimatic conditions (Last Glacial Maximum and mid-Holocene) in shaping the current structure of soil bacterial communities in natural and agricultural soils. We show that palaeoclimate explains more of the variation in the richness and composition of bacterial communities than current climate. Moreover, palaeoclimate accounts for a unique fraction of this variation that cannot be predicted from geographical location, current climate, soil properties or plant diversity. Climatic legacies (temperature and precipitation anomalies from the present to ~20 kyr ago) probably shape soil bacterial communities both directly and indirectly through shifts in soil properties and plant communities. The ability to predict the distribution of soil bacteria from either palaeoclimate or current climate declines greatly in agricultural soils, highlighting the fact that anthropogenic activities have a strong influence on soil bacterial diversity. We illustrate how climatic legacies can help to explain the current distribution of soil bacteria in natural ecosystems and advocate that climatic legacies should be considered when predicting microbial responses to climate change.

We tested the activity of ETX0914 against 187 Neisseria gonorrhoeae isolates from men with urethritis in Nanjing, China, in 2013. The MIC50, MIC90, and MIC range for ETX0914 were 0.03 μg/ml, 0.06 μg/ml, and ≤0.002 to 0.125 μg/ml, respectively. All isolates were resistant to ciprofloxacin, and 36.9% (69/187) were resistant to azithromycin. Of the isolates, 46.5% were penicillinase-producing N. gonorrhoeae (PPNG), 36% were tetracycline-resistant N. gonorrhoeae (TRNG), and 13% (24 isolates) had an MIC of 0.125 μg/ml for ceftriaxone. ETX0914 may be an effective treatment option for gonorrhea., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Super absorbent polymers (SAPs) are compounds that can absorb a lot of water which can be several folds of their original size and weight. They can increase soil water content and aggregates, promote fertilizer utilization efficiency, and stimulate crop growth. Therefore, SAPs have been widely regarded as a potential agent for water-saving agriculture. In this paper, we reviewed the advances of SAPs in materials, properties and applications in agriculture and pointed out that the absence of influences of SAPs on soil microbial ecology was the main issue in current studies. In regard to the adverse effects on soil environment caused by misuse of SAPs, we should address the systematic safety assessment of SAPs application in the soil, especially the effects on the soil microorganisms, which should be an important part of chemicals risk assessment in the soil application.

Background: Cancer chemoprevention is a proven effective strategy for oral squamous cell carcinoma (OSCC). The present study was designed to investigate the effects of crocin, a potential chemopreventive agent, on growth and DNA and RNA content in a human tongue squamous cell carcinoma cell line, Tca8113., Methods: Tca8113 cells were treated with crocin for 24, 48, 72, and 96 h at concentrations of 0.1, 0.2, 0.4, and 0.8 mM. Tumor cell viability was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. In addition, Tca8113 cells were treated with 0.4 mM crocin and cytotoxic effects as an inducer of apoptosis were analyzed using flow cytometry. Furthermore, acridine orange (AO) staining and observation using laser scanning confocal microscopy (LSCM) were used to determine the effects of the drug on nucleic acid synthesis., Results: Crocin decreased Tca8113 cell viability and growth remarkably at 24, 48, 72, and 96 h, in a concentration-dependent manner (P<0.05). In addition, 0.4 mM crocin significantly induced both early and late apoptosis of Tca8113 cells. Moreover, the cellular DNA and RNA content was significantly downregulated by 0.4 mM crocin compared with the negative control (P<0.01)., Conclusions: Our observations support the feasibility of applying crocin as a chemoprophylactic agent and treatment for OSCCs.

Objective: Carboplatin (CBP)-resistant cell line (Tca8113/CBP) and pingyangmycin (PYM)-resistant cell line (Tca8113/PYM) were established in vitro. Ginkgolic acids' influence over multidrug resistance (MDR) of drug-resistant cells was discussed by ginkgolic acids coupled with chemotherapy drugs., Methods: The expression of P-glycoprotein (P-gp) was detected by immunohistochemistry. MTT assay was applied to ascertain the resistance index of drug-resistant cells. The effect of different concentrations of ginkgolic acids on the proliferation of drug-resistant cells and parental cell was measured by MTT assay. Making sure the non-toxic concentration of ginkgolic acids and observing the reversal effect of ginkgolic acids on drug-resistant cells. Resistance index was redetermined by MTT assay after ginkgolic acids coupled with chemotherapy drugs induced the cell lines for some time., Results: Immunohistochemistry showed that P-gp positive expression rate of drug-resistant cells was significantly higher than parental cells. The non-toxic concentration of ginkgolic acids which was determined by MTT assay was 10 microg x mL(-1). The reversal folds of Tca8113/CBP cell line to CBP and Tca8113/PYM cell line to PYM were 2.94 and 2.43 respectively. Before coupled with ginkgolic acids, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 3.24 and 11.9 respectively. When ginkgolic acids was added with chemotherapy drugs for some time, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 2.18 and 4.43 respectively., Conclusion: This experiment successfully induced the drug-resistant cell lines of Tca8113/CBP and Tca8113/PYM. The method of chemotherapy drugs coupled with ginkgolic acids further confirmed the effect on proliferation of Tca8113/CBP and Tca8113/PYM cell lines was reducing. Non-toxic concentration of ginkgolic acids can partially reverse the drug resistance of Tca8113/ CBP and Tca8113/PYM cell lines. Furthermore, MDR level of drug-resistant cells decreased somewhat when they were induced by ginkgolic acids coupled with chemotherapy drugs for some time.

Based on the Cambisols of Beijing (used as agricultural soils), toxicity tests were conducted to investigate the effects of mercury (Hg) on reproduction and avoidance of Folsomia candida (Hexapoda: Collembola), as well as the transcriptional responses of the hsp70 gene, under different Hg concentrations and at different exposure times. Results showed that the hsp70 gene of the springtail was the most sensitive parameter to soil Hg stress, with a half-maximal effective concentration (EC50) of 0.42 mg/kg. The EC50 values based on reproduction and avoidance tests were 9.29 and 3.88 mg/kg, respectively. The expression level of the hsp70 gene was significantly up-regulated when soil Hg concentration was over 0.25 mg/kg (lowest-observed-effect concentration [LOEC]). In addition, responses of this gene expression were strongly induced after 48 h exposure under 1 mg/kg soil Hg, which probably was due to the fast and sensitive response of the gene transcription to Hg stress. Thus, the results suggested that the responses of the hsp70 gene and individual-level effects (reproduction and avoidance) could be integrated to provide helpful information for environmental monitoring and assessment of contaminated soils.

Objective: To study the anti-tumor effects and its mechanism of hTR-siRNA adenovirus on human cervical cancer in vivo., Methods: The in vivo model of human cervical cancer was established by the subcutaneous inoculation of HeLa cells at the right armpit of BALB/c nu/nu mice. After successful implantation, the mice were randomized into four groups, in which the mice were intratumorally injected with 0.1 mL of Ad-hTR-siRNA (10(13) pfu/L), or Ad-NT-siRNA (10(13) pfu/L), or Cisplatin (1.20 g/L), or serum-free DMEM alone respectively. These treatments were given once every 3 days for 6 times. After the last injection, the mice were observed for 7 days continuously and sacrificed at the end. The tumors were harvasted, weighed, and sectioned. The TUNEL assay was used to assess the apoptosis of these tumor cells., Results: Tumors-implanted were established successfully by 100% with HeLa cells. As compared with Ad-NT-siRNA, Ad-hTR-siRNA could slow down tumor growth, decrease tumor volume (45.48%) and tumor weight (34.68%), as well as promote the apoptosis and necrosis of tumor cells. The TUNEL positive cells were about 11.8%. But the anti-tumor activity of Ad-hTR-siRNA didn't catch on Cisplatin's., Conclusion: This study indicated that the hTR-siRNA adenovirus could suppress cervical cancer-xenografted growth in vivo and induce tumor cell apoptosis or necrosis.

To provide information on the screen of newly and efficient algaecides in controlling harmful algal blooms (HABs), the effects of wood meals from Eucalyptus torelliana, Eucalyptus urophylla, Eucalyptus exserta on the growth of Alexandrium tamarense were observed and the chemical basis of the antialgal effect was discussed. The results show that the inhibitory activities of the three wood meals are different, and E. torelliana wood meals have the highest inhibitory activity. There are little differences in antialgal action between asepsis and rude wood meals, suggesting that some antialgal compounds from wood meals may be responsible for the inhibition and that microorganisms from wood meals have little effect on the inhibition. The acetone-water extract from E. torelliana wood meals is shown to have stronger inhibition on A. tamarense than that from ethyl acetate, water and methanol extracts. The acetone-water extract from E. torelliana wood meals was further divided into extract A, B, C and D and the inhibitory activities were compared. The extract D is shown to have highest inhibitory activity. 3 mg/L of the extract appears 81% inhibition rate to A. tamarense in the 3rd day. GC-MS show that extract D contains mostly ketones such as 4-hydroxy-3,5,6-trimethyl-4-(3-oxo-1-butenyl)-2-cyclohexen-1-one and 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-2(4H)-benzofuranone. These results suggest that wood meals from E. torelliana had certain inhibitory effect on A. tamarense, and that ketones may be responsible for the inhibition.