The regulation effect of preventing soil nitrogen loss using microbial quorum sensing inhibitors.

Preventing soil nitrogen (N) losses driven by microbial nitrification and denitrification contributes to improving global environmental concerns caused by NO3--N leaching and N2O emission. Quorum sensing (QS) signals regulate nitrification and denitrification of N-cycling bacteria in pure culture and water treatment systems, and mediate the composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in activated sludge. However, whether disrupting QS could prevent soil N losses remains unclear. This study explored the feasibility of applying quorum sensing inhibitors (QSIs) as an innovative strategy to reduce N losses from agricultural soils. The two QSIs, penicillic acid and 4-iodo-N-[(3S)-tetrahydro-2-oxo-3-furanyl]-benzeneacetamide (4-iodo PHL), were more effective in reducing N losses than traditional inhibitors, including N-(n-butyl) thiophosphoric triamide and 3,4-dimethylpyrazole phosphate. After 36 days of aerobic incubation, penicillic acid and 4-iodo PHL inhibited nitrification by 39% and 68%, respectively. The inhibitory effects are attributed to the fact that 4-iodo PHL decreased the abundance of archaeal and bacterial amoA genes, as well as the relative abundance of Candidatus Nitrocosmicus (AOA), Candidatus Nitrososphaera (AOA), and Nitrospira (nitrite-oxidizing bacteria/comammox), while penicillic acid reduced archaeal amoA abundance and the relative abundance of Nitrosospira (AOB) and the microbes listed above. Penicillic acid also strongly inhibited denitrification (33%) and N2O emissions (61%) at the peak of N2O production (day 4 of anaerobic incubation) via decreasing nitrate reductase gene (narG) abundance and increasing N2O reductase gene (nosZ) abundance, respectively. Furthermore, the environmental risks of QSIs to microbial community structure and network stability, CO2 emissions, and soil animals were acceptable. Overall, QSIs have application potential in agriculture to reduce soil N losses and the associated effect on climate change. This study established a new method to mitigate N losses from the perspective of QS, and can serve as important basis of decreasing the environmental risks of agricultural non-point source pollution.

Characteristics and pregnancy outcomes of subtypes of gestational diabetes mellitus based on HOMA-IR and BMI.

AIM: To identify the characteristics and pregnancy outcomes across different subgroups of gestational diabetes mellitus (GDM) categorized by insulin resistance index and body mass index (BMI) in early pregnancy. METHODS: This retrospective study included 1804 women who underwent a 75 g-OGTT during 22-28 weeks of gestation, categorized into normal glucose tolerance (NGT) (1487) and GDM (317 [17.57%] of the total cohort). Metabolic parameters were assessed, and equation of homeostatic model assessment (HOMA) were utilized to compute indices of insulin resistance (HOMA-IR), ß-cell secretory (HOMA-B), and insulin sensitivity (HOMA-%S) in early and mid-pregnancy. The cut-off value of HOMA-IR (1.61) in early pregnancy was determined via ROC curve analysis. This value, combined with pre-pregnancy BMI, further categorized NGT and GDM into six subgroups respectively, based on HOMA-IR levels (≥ 1.61 or < 1.61) and BMI categories (< 18.5 kg/m2, 18.5-25 kg/m2, or ≥ 25 kg/m2). RESULTS: In comparison to women with NGT, those with GDM were notably older, had higher pre-BMI, fasting plasma glucose (FPG), insulin, and lipid levels in early pregnancy. They also exhibited more pronounced insulin resistance in both early and mid-pregnancy, leading to poorer outcomes. Following an oral glucose load, the peaks of glucose and insulin were out of sync in GDM and its subgroups, accompanied by further increases in HOMA-IR, HOMA-B, and a decrease in HOMA-%S, except for the GDM subgroup with HOMA-IR < 1.61/BMI < 18.5 kg/m2. Conversely, glucose and insulin secretion in NGT and its subgroups peaked synchronously at 60 min. GDM women with HOMA-IR ≥ 1.61/18.5 kg/m2 ≤ BMI < 25 kg/m2 had higher rates of neonatal jaundice (34.5% vs 13.9%, p < 0.0001), LGA (28.9% vs 13.2%, p = 0.001), macrosomia (9.8% vs 3.7%, p = 0.025) compared to peers, while in GDM women with HOMA-IR ≥ 1.61/BMI ≥ 25 kg/m2, the rates of LGA and macrosomia were 26.6% and 8.4%, respectively. The GDM subgroup with HOMA-IR < 1.61/BMI < 18.5 kg/m2 exhibited the highest rates of premature rupture of membrane (46.7%) and postpartum hemorrhage (20%), predominantly with vaginal delivery and a 1 min Apgar score of 4.5% in GDM women with HOMA-IR < 1.61/18.5 kg/m2 ≤ BMI < 25 kg/m2. CONCLUSION: GDM and its subgroups displayed severe insulin resistance and poorer insulin sensitivity, leading to an increased risk of adverse pregnancy outcomes. GDM women with higher IR and normal or over weight were more likely to experience LGA and macrosomia, while those with lower IR and underweight were prone to premature rupture of membrane and postpartum hemorrhage during vaginal delivery.

Temperature-Dependent Bioaccumulation, Metabolism, and Hepatotoxicity of Flufiprole in Lizards (Eremias argus).

As a phenylpyrazole insecticide, flufiprole is an important substitute for fipronil in the agricultural field of China. However, its bioaccumulation and metabolism in terrestrial organisms especially in the lizards living in the agricultural area have rarely been investigated. As an ectothermic animal, lizards are also sensitive to temperature changes. Considering global warming, this study measured bioaccumulation, metabolism, and hepatotoxicity of flufiprole in the Chinese native lizard (Eremias argus) under different temperature stresses. Lizards exposed to flufiprole-contaminated soil adsorbed flufiprole through the skin and flufiprole was preferred to accumulate in lizard liver and brain. The oxidation product fipronil sulfone was the main metabolite of flufiprole in both lizard liver and human liver microsomes, which were mainly metabolized by lizard CYP3A19 or human CYP3A4. The fipronil sulfone concentration increased with increased temperature in lizard tissues. In addition, more serious oxidative damage was shown under higher temperature as the glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in lizards increased with increased temperature after flufiprole exposure. Flufiprole exposure also induced lizard liver lesions, and these lesions became more serious in the higher-temperature groups. This study provided new insights into the risk assessment of flufiprole in lizards under global warming.

MicroRNA-184 Modulates Human Central Nervous System Lymphoma Cells Growth and Invasion by Targeting iASPP.

Central nervous system lymphoma (CNSL) remains a diagnostical and therapeutical challenge. MiRNAs post-transcriptionally regulate expression of targeted mRNAs through binding to their 3' UTR to inhibit their translation or promote their degradation. Oncoprotein inhibitory member of the ASPP family (iASPP), a key inhibitor of tumor suppressor p53, has been reported to play oncogenic role in cancers. Our present study was aimed to determine whether the miR-184/iASPP axis is involved in the proliferation and invasion of CNSL. A reduced level of miR-184 was observed in CNSL tissues. Exogenous miR-184 inhibited cell survival and invasion, as well as the tumor volumes, while miR-184 inhibition could reverse this process. The RNA and protein levels of iASPP were significantly inhibited by miR-184, and the 3' UTR of iASPP was shown to be a target of miR-184. The expression of iASPP was up-regulated in CNSL tissues, compared to that of the normal brain tissues. The inhibition of iASPP by shRNA iASPP significantly repressed CNSL cells' proliferation and invasion, and reduced the volume of the tumor. Besides, iASPP overexpression could partly restore the suppressive effect of miR-184 on CNSL cell proliferation and invasive capability. We also revealed that miR-184/iASPP axis regulated the proliferation and invasion via PI3K/Akt signaling pathway, which presents a novel potential therapy for intervention of CNSL. Taken together, our findings revealed the detailed role of the miR-184/iASPP axis in CNSL and this axis might modulate the proliferation and invasion of CNSL via regulating the PI3K/Akt signaling pathway. J. Cell. Biochem. 118: 2645-2653, 2017. © 2017 Wiley Periodicals, Inc.

Absorption, distribution, metabolism, and elimination of epoxiconazole enantiomers in lizards (Eremias argus).

Epoxiconazole (EPX) is a world widely used chiral triazole fungicide in the agriculture field. The excessive application of this triazole may cause damage to lizards. However, limited information is known about the toxicokinetics of EPX on lizards. Our study aimed to investigate the enantioselective absorption, distribution, metabolism, and elimination (ADME) of EPX in lizards following low and high dose exposure (10 and 100 mg kg-1 bodyweitht (bw)). The results demonstrated that (+)-EPX was easier absorbed than (-)-EPX in lizard plasma. Both (+)-EPX and (-)-EPX were detected in the liver, gonad, kidney, skin, brain, and intestine, with (+)-EPX preferentially distributed in these tissues. The elimination of (-)-EPX was faster than that of (+)-EPX in lizard liver and kidney in the high dose groups. Chiral conversion was found between EPX enantiomers in lizard skin. Simultaneously, five metabolites including M2, M4, M10, M18 and M19 were detected in lizard liver and kidney after EPX enantiomers exposure. The relative concentrations of M2, M4, and M10 were higher in the liver and kidney of (-)-EPX groups than those produced from (+)-EPX groups. The metabolic enzymes CYP3A4 and SULT1A1 primarily mediated enantioselective metabolism of EPX. The conclusions drawn from this study significantly enhance our understanding of the enantioselective behaviors of chiral triazole fungicides in reptiles, offering essential guidance for assessing the risks associated with different enantiomers of triazole fungicides.

Postoperative delirium prediction after cardiac surgery using machine learning models.

OBJECTIVE: Postoperative delirium (POD) is a common postoperative complication in elderly patients, especially those undergoing cardiac surgery, which seriously affects the short- and long-term prognosis of patients. Early identification of risk factors for the development of POD can help improve the perioperative management of surgical patients. In the present study, five machine learning models were developed to predict patients at high risk of delirium after cardiac surgery and their performance was compared. METHODS: A total of 367 patients who underwent cardiac surgery were retrospectively included in this study. Using single-factor analysis, 21 risk factors for POD were selected for inclusion in machine learning. The dataset was divided using 10-fold cross-validation for model training and testing. Five machine learning models (random forest (RF), support vector machine (SVM), radial based kernel neural network (RBFNN), K-nearest neighbour (KNN), and Kernel ridge regression (KRR)) were compared using area under the receiver operating characteristic curve (AUC-ROC), accuracy (ACC), sensitivity (SN), specificity (SPE), and Matthews coefficient (MCC). RESULTS: Among 367 patients, 105 patients developed POD, the incidence of delirium was 28.6 %. Among the five ML models, RF had the best performance in ACC (87.99 %), SN (69.27 %), SPE (95.38 %), MCC (70.00 %) and AUC (0.9202), which was far superior to the other four models. CONCLUSION: Delirium is common in patients after cardiac surgery. This analysis confirms the importance of the computational ML models in predicting the occurrence of delirium after cardiac surgery, especially the outstanding performance of the RF model, which has practical clinical applications for early identification of patients at risk of developing POD.

Exploration of the anti-hyperuricemia effect of TongFengTangSan (TFTS) by UPLC-Q-TOF/MS-based non-targeted metabonomics.

BACKGROUND: TongFengTangSan (TFTS) is a commonly used Tibetan prescription for gout treatment. Previously, TFTS (CF) was confirmed to have a significant uric acid-lowering effect. However, the anti-hyperuricemia mechanisms and the main active fractions remain unclear. The current study aimed to investigate the anti-hyperuricemia mechanism using metabolomics and confirm the active CF fraction. METHODS: The hyperuricemia model was established through intraperitoneal injection containing 100 mg/kg potassium oxonate and 150 mg/kg hypoxanthine by gavage. We used serum uric acid (sUA), creatinine (CRE), blood urea nitrogen (BUN), xanthine oxidase (XOD) activity, interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) as indicators to evaluate the efficacy of CF and the four fractions (SX, CF30, CF60, and CF90). The anti-hyperuricemia mechanism of CF was considered through non-targeted metabolomics depending on the UPLC-Q-TOF-MS technology. Principle component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) helped explore the potential biomarkers in hyperuricemia. Moreover, the differential metabolites and metabolic pathways regulated by CF and four fractions were also assessed. RESULTS: CF revealed a significant anti-hyperuricemia effect by down-regulating the level of sUA, sCRE, sIL-1ß, and XOD. SX, CF30, CF60, and CF90 differed in the anti-hyperuricemia effect. Only CF60 significantly lowered the sUA level among the four fractions, and it could be the main efficacy fraction of TFTS. Forty-three differential metabolites were identified in hyperuricemia rats from plasma and kidney. Pathway analysis demonstrated that seven pathways were disrupted among hyperuricemia rats. CF reversed 19 metabolites in hyperuricemia rats and exerted an anti-hyperuricemia effect by regulating purine metabolism. CF60 was the main active fraction of TFTS and exerted a similar effect of CF by regulating purine metabolism. CONCLUSIONS: CF and CF60 could exert an anti-hyperuricemia effect by regulating the abnormal purine metabolism because of hyperuricemia while improving intestinal and renal function. CF60 could be the main active fraction of TFTS.

[Analgesic effect and mechanism of electroacupuncture on SNI rats based on microglia-BDNF-neuron signal].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the activation of glial cells, the expression of brain-derived neurotrophic factor (BDNF), excitability and the number of dendritic spines of neurons in the spinal dorsal horn in rats with spared nerve injury (SNI) of sciatic nerve, and to explore the analgesic mechanism of EA on SNI. METHODS: PartⅠ: Sixty SD rats were randomly divided into a sham operation group, a model group, an EA group and a sham EA group, 15 rats in each group. Except the sham operation group, the SNI rat model was established in the remaining groups. The rats in the sham operation group were only treated with incision without damaging the nerve. The rats in the EA group were treated with EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side, continuous wave, frequency of 2 Hz, current intensity of 1 mA, 30 minutes each time, once a day, for 14 days. The rats in the sham EA group were treated with EA at points 0.5 cm next to "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side; the manipulation, EA parameters and treatment course were the same as the EA group. The latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex were detected 1 day before modeling and 3, 7 and 14 days after modeling. Fourteen days after modeling, Western blot was used to detect the protein expressions of ionized binding adapter junction protein 1 (Iba-1), glial fibrillary acidic protein (GFAP), BDNF and c-Fos in the spinal dorsal horn; the expressions of Iba-1 and c-Fos proteins in the spinal dorsal horn were detected by immunofluorescence staining; immunohistochemical method was used to detect the expression of GFAP protein in the spinal dorsal horn; Golgi staining was used to detect the number of dendritic spines in spinal dorsal horn neurons. PartⅡ: Thirty SD rats were randomly divided into a control group, a BDNF group and a BDNF+anti-TrkB group, 10 rats in each group. The control group was treated with intrathecal injection of 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and dimethyl sulfoxide (DMSO); the BDNF group was treated with intrathecal injection of 10 µg rat recombinant BDNF dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO; the BDNF+anti-TrkB group was treated with intrathecal injection of 10 µg rat recombinant BDNF and 30 µg tyrosine kinase receptor B (TrkB) antibody dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO. The threshold of mechanical foot retraction reflex was detected 1 day before intrathecal injection and 1, 3 and 7 days after injection. Seven days after injection, the expression of c-Fos protein in the spinal dorsal horn was detected by Western blot and immunofluorescence staining. RESULTS: PartⅠ: Compared with the sham operation group, 3, 7 and 14 days after modeling, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the model group were decreased (P<0.05); 7 and 14 days after modeling, compared with the model group, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the EA group were increased (P<0.05). The expressions of Iba-1, GFAP, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the spinal dorsal horn in the model group were higher than those in the sham operation group (P<0.05); the expressions of Iba-1, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the EA group were lower than those in the model group (P<0.05). PartⅡ: 3 and 7 days after intrathecal injection, the threshold of mechanical foot retraction reflex in the BDNF group was lower than that in the control group (P<0.05); the threshold of mechanical foot retraction reflex in the BDNF+anti-TrkB group was higher than that in the BDNF group (P<0.05). The expression of c-Fos protein in spinal dorsal horn in the BDNF group was higher than that in the control group (P<0.05); the expression of c-Fos protein in spinal dorsal horn in the BDNF+anti-TrkB group was lower than that in the BDNF group (P<0.05). CONCLUSION: The analgesic effect of EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on SNI rats may be related to inhibiting the activation of microglia in the dorsal horn of the spinal cord, thereby blocking the signal of microglia-BDNF-neuron, and finally reducing the excitability of neurons.

Effects of General Anesthesia Combined with Epidural Anesthesia on Cognitive Dysfunction and Inflammatory Markers of Patients after Surgery for Esophageal Cancer: A Randomised Controlled Trial.

OBJECTIVE: To evaluate the impact of general anesthesia (GA) combined with epidural anesthesia (GAEA) on postoperative cognitive dysfunction (POCD) and inflammatory markers in patients with esophageal cancer (EC).   Study Design: A randomised controlled trial. PLACE AND DURATION OF STUDY: Department of Anesthesiology, Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, Sichuan Province, China, from August 2019 to April 2020. METHODOLOGY: SPSS was used to randomly divide 142 cases into two groups, namely: the GA (n=71) and GAEA (n=71) categories. 128 candidates were used in this study. Cognitive function and the levels of interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis markers α (TNF-α) in serum were evaluated at baseline, 1, 3 and 7 days after operation by Montreal Cognitive Assessment (MoCA) and enzyme-linked immunosorbent assay (ELISA), respectively. Pearson correlation analysis was used to assess the interrelationships between MoCA score and inflammatory markers levels. RESULTS: Compared to the GA group (n=64), the GAEA category (n=64) showed significantly higher MoCA score on 1 day and 3 days postoperatively (all p <0.05). IL-6, IL-8 and TNF-α in the GA group were significantly increased on 1, 3 and 7 days after surgery (all p <0.05). Pearson correlation analysis indicated that the three inflammatory markers were inversely correlated with cognitive function score (all p <0.05). The postoperative adverse events between the two groups were comparable (all p >0.05). CONCLUSION: Combining general and epidural anesthesia may reduce the incidence of POCD in patients undergoing esophagectomy by suppressing inflammatory response. Key Words: General anesthesia, Epidural anesthesia, Esophageal cancer, Postoperative cognitive dysfunction, Inflammatory markers.

[Agro-household livelihood vulnerability and influence factors of ethnic villages under different geomorphology backgrounds.] / ä¸åŒåœ°è²ŒèƒŒæ™¯ä¸‹æ°‘æ—æ‘å†œæˆ·ç”Ÿè®¡è„†å¼±æ€§åŠå ¶å½±å“å› å­.

The vulnerability and influence factors of agro-household livelihood in Haiyuan County, Ningxia were empirically analyzed utilizing set pair analysis and obstacle degree model, based on field survey data of impoverished agro-households in 2014. Results showed that vulnerability of agro-household livelihood in Haiyuan County was high in general while it exhibited geomorphological and ethnical differences. Vulnerability of agro-households livelihood in plain areas, valleys and intermountain depression areas were lower than that in earth-rock areas, loess ridge areas and moderately high mountain landform areas. Moreover, vulnerability of agro-household livelihood was higher in mixed Hui and Han ethnic villages than in mono Hui or Han ethnic villages. The villagers' lacking of necessities and the stress of sensitive external geographical environment were considered to be the fundamental reasons of vulnerability of agro-household livelihood. The unreasonable livelihood structure and the unvariant livelihood strategy caused the long-term accumulation of livelihood vulnerabi-lity. The nature of the local environment, which was not easy to change, decreased the accessibility of poverty alleviation resources. Building a clear village water rights allocation system, the implementation of counterpart-assistance to educate impoverished families, increasing investment in improving the diversities of means of living, developing the chains of comprehensive commodity market among villages, were necessary to improve the response capability of agro-household livelihood. The management of vulnerability of agro-household livelihood should put the 'Extending Roads to Every Village Project' on a more prominent position in the 'Extending Radio and TV Broadcasting Coverage to Every Village Project'. Furthermore, the combination of meteorological disaster prevention and insurance enterprise disaster reduction should be sought, and the agricultural production insurance system should be developed.

[Comparative study on pesticide and heavy metal residuals of four cultivars of Chrysanthemum morifolium].

OBJECTIVE: To study organochlorine pesticide and heavy metal residuals of Chrysanthemum morifolium. METHOD: The contents of organochlorine pesticide residuals was determined by chromatography, Cu, Pb, Cd was determined by AAS, and As, Hg was determined by AFS. RESULT AND CONCLUSION: The contents of organochlorine pesticide and heavy metals residuals are up to "Green Trade Standards of Importing & Exporting Medicinal plants & Preprations" (MOFTEC, 2001), but the contents are different among four cultivars clearly.

RP-HPLC method using one marker for quantification of four podophyllum lignans in medicinal plants.

A high-performance liquid chromatographic method using a single standard has been established for the quantitative analysis of four podophyllum lignans in Dysosma versipellis (Hance) M. Cheng and Podophyllum emodi Wall. Var. chinesis Sprague. The method involved the quantitative analysis of multiple components by a single marker. The chromatographic method was validated for linearity and range, limit of detection and qualification, precision, stability, reproducibility and robustness. Relative correcting factors were calculated and examined by five concentrations of four podophyllum lignans, two high-performance liquid chromatographic systems and three chromatographic columns. The method was applied to analyze 10 batches of samples. The quantitative results were compared with the results by an external standard method through intra-class coefficient, which indicated that the established method was reliable for the determination of the four podophyllum lignans in the two medicinal plants.

Contamination and congener profiles of polychlorinated biphenyls from different agricultural top soils in a county of the Tailake Region, China.

Hundred topsoil (0-20 cm) samples under different land use types were collected from a county in the Tailake Region, China and analyzed for 18 polychlorinated biphenyls (PCBs) including five dioxin-like PCBs. The mean concentration of total PCBs (SigmaPCBs) for all sites was 1.071 microg kg(-1) dry weight (dw) with a range of 0.016 microg kg(-1) to 4.050 microg kg(-1), and the concentration of total Dioxin-like PCBs (SigmaDioxin-like PCBs) was 0.352 microg kg(-1) about 33% of SigmaPCBs. The concentration of SigmaPCBs in paddy field (PF) soils with a mean of 1.63 microg kg(-1) was higher than that in vegetable soil with a mean of 0.882 microg kg(-1), but the concentration of Dioxin-like PCBs in PF soil was lower than that in commercial vegetable production soil. The concentration of heavier weighted molecular PCB congeners (> or = penta-PCBs) in vegetable soil accounted for 98% of SigmaPCBs, while that in Paddy field soil for 65% of SigmaPCBs.

[Adsorption of cyromazine on five typical soils in China].

Batch equilibrium experiments were used to reveal cyromazine adsorption on five kinds of soils, namely Ali-Perudic Ferrosols collected from Yingtan of Jiangxi, Udic Argosols collected from Nanjing and Gleyic-Stagnic Anthrosols collected from Changshu of Jiangsu, Ustic Cambosols collected from Fengqiu of Henan, and Udic Isohumosols collected from Hailun of Heilongjiang. Results show that the experimental data are best described by the Freundlich and Langmuir model, while fitted successfully by the linear model. Different adsorption behaviors of Cyromazine are observed in the five tested soils, with the lgK(f) values varying from 1.6505 (cambosols), 1.6715 (argosols) and 1.7153 (ferrosols) to 2.4579 (anthrosols) and 2.6557 (isohumosols). Moreover, the Kf values are in a positive correlation to the OM of the soil (r = 0.989) but significantly negative correlated to soil pH (r = -0.938). The free energy of sorption ranged from -20.8 to -23.0 kJ/mol, indicated that the adsorption could be largely attributed to the physical adsorption.

[Risk of soil salinisation by application of concentrated animal manures].

The salt content in 180 samples of concentrated animal manures collected in Jiangsu Province was analyzed and the risk of soil salinisation by the application of manures was evaluated by the methods of spatial analysis on GIS and simulating prediction on the accumulation model of salt in soil. The salt content in animal manures was high, with the highest value of 24.2 g x kg(-1) (dry weight). The risk of potential soil salinisation might exist in the coastal region such as Nantong, Yancheng, Lianyungang and the Xuhuai region such as Xuzhou, Suqian, Huaian with the application of animal manures. There was nearly no risk of salinisation by the application of animal manures on the open-field soil, but was obvious influence on the greenhouse soil, the salt content in the greenhouse soil increased by 1.0-2.5 g x kg(-1) after 65-100 t x (hm2 x a)(-1) dry animal manure with the salt content of 24.2 g x kg(-1) was applied for 2-8 a, which might cause mild, moderate or strong soil salinisation.

[Dynamics of DDMS and DDMU in soils under rice and ryegrass planting].

Dynamics of DDMS and DDMU in soils with DDT application under rice and ryegrass planting by pot experiment in greenhouse was conducted. Results show that DDE/DDD is slightly increased, and only about 20 ng x g(-1) DDMU or DDMS could be found in ryegrass soil at the end of the experiment. However, the DDD, DDMS and DDMU are formed very rapidly in rice soil. By the 84th day of the experiment of rice planting, DDT residue is 70-80 ng x g(-1), about 2% of the concentration added at the first of the experiment, meanwhile, concentrations of DDD, DDMS and DDMU are increased to the highest level. Concentration of DDMS and DDMU is detected at 28 and 115 ng x g(-1) respectively. On the other hand, above phenomena are not observed in the aged DDT of soils, which implies that submerging could increase degradation of DDT added newly to DDD and DDMS/DDMU, but not for the aged DDT of soils.

[Residues and distribution character of organochlorine pesticides in stream sediments in southwestern suburb of Nanjing].

Sediments and water samples were collected from different cross sections of 4 tributaries of Yangtze River in southwestern suburb of Nanjing city in spring 2004, and agricultural soil sample were collected also in those valleys. The residues and distribution of organochlorine pesticides in sediments from different streams were determined and the influence of soil character on organochlorine pesticides residues in sediments were studied. Result showed that accumulation of HCHs and DDTs occured significantly in the sediments and related to soil erosion. Residues of organochlorine pesticides in sediments may be influenced obviously by pH of agricultural soil in the valleys. In the alkaline soil, organic matters could be leached easily and entered the stream water and accumulated into sediments, resulting in accumulation of organochlorine pesticides adsorbed on soil organic matters in sediments. In the transfer process of materials from soil to water and sediment, constitutes of organochlorine pesticides in multiphase environmental medium were changed; usually those components easily leached from soils had higher residue levels in sediments. Meanwhile, sedimentation of soil in streams could reduce OCPs input to the Yangtze River.

[Distribution characteristics and sources identification of PAHs in ancient paddy soil].

Soil samples of current paddy soils, ancient paddy soil/ancient dry land soil, and bottom soils were collected from two sites in Chuodunshan Site of Majiabang Culture (about 6,000a). 15 polycyclic aromatic hydrocarbons (PAHs) were analyzed with HPLC, and their possible sources were identified. The sum of 15 PAHs was 202.9microg x kg(-1) and 207.7microg x kg(-1) in the surface soils from Site A and Site B respectively, which were mainly deposited from atmosphere. In ancient paddy soil from Site A, the total PAHs concentration sharply decreased to 56.0microg x kg(-1), but was still higher than those in ancient dry land soil and bottom soils with the sum of 32.0 approximately 36.9microg x kg(-1). In ancient paddy soil, the concentrations of 2-ring and 3-ring PAHs took a larger portion of 63 percents to the total PAHs, and naphthalene and phenanthrene were the most abundant compounds, while PAHs of more than 4 rings took a small part. The ratios of phenanthrene anthracene and benzo(a) anthracene chrysene and 13C-NMR spectrum of soil organic matter showed that PAHs in ancient paddy soil mainly originated from rice straw burning, biogenesis under reducing conditions may be another source.

[Bioindication of organochlorine pesticides by night heron in Taihu wetland ecosystem].

Based on field ecological investigation on the colony of herons in Yuantouzhu of Taihu in 1999, the regurgitated foods by chicks of night heron were collected for prey type identification and chemical analysis. Besides, eggs of night heron, and sediments and waters in foraging habitats were sampled for chemical analysis as well. alpha-HCH, beta-HCH, gamma-HCH, Aldrin, Dieldrin, Endrin, Heptachlor, Heptachlor epoxide, p,p'-DDE, p,p'-DDD, o,p'-DDT and p,p'-DDT were determined in laboratory by gas chromatography. The results indicated that HCH isomers, DDT and its metabolites could be detected in various environments and preys of night heron, although the organochlorined chemicals were banned for almost 20 years. Moreover, The results showed that eggs of night heron could accumulate organochlorine pesticides by as much as a factor of 10(3)-10(4), which can make chemical analysis much easier. So they are good bio-indicators for organochlorine contamination level in wetland environments.

[Residue and distribution of heavy metals in tissues of night heron chick bred in Yuantouzhu, Wuxi].

This study analyzed Cd, Pb, Cr, Hg and Se in organs and tissues of night heron chick bred in Yuantouzhu, Taihu lake. Cr and Se have higher residue level in all the samples, compared to the residue of Cd, Pb and Cd mainly concentrated in feathers, on the other hand, Se, Hg and Cr were accumulated in livers. The results proofed that feather and liver were the object organs for accumulation of heavy metals. The data showed that Hg and Cd have some relationship with Se in birds. Compared with other studies, residue levels of heavy metals in night heron in Wuxi were not harmful.