[HCV antigen detection method and clinical application].

Hepatitis C is distributed worldwide and possesses a hidden characteristic. The traditional methods of screening and diagnosis of hepatitis C infection commonly used in clinics are based on anti-HCV antibody and HCV RNA detection. Advances in HCV antigen detection technologies can apparently reduce the window period for anti-HCV antibodies, providing new clinical evidence for the early detection, diagnosis, and treatment of HCV infection. This article is a current review of HCV antigen detection methodologies, clinical applications, and detection strategies.

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering.

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8 (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

[Research on mental health status of medical staff during COVID-19 epidemic].

Objective: To explore the psychological status of medical staff during COVID-19 epidemic, so as to provide reference and scientific basis for carrying out further psychological intervention and ensuring the mental health of medical staff. Methods: By using convenient sampling method and the Stresss-Anxiety ubscale of Depression Anxiety Stress (DASS-21) , the mental health status of 615 medical staff was investigated by the way of questionnaire star from February 4 to 16, 2020. A total of 615 questionnaires were distributed and collected, and 615 were valid, with an effective recovery rate of 100%. Results: The detection rates of psychological stress and anxiety of medical staff were 13.82% (85/615) and 25.37% (156/615) , respectively. 31-40 years old and working in key departments were risk factors for psychological stress of medical staff (OR=1.779, 2.127) ; Women, frequently washing hands with soap/hand sanitizer/disinfectant were protective factors for psychological stress (OR=0.520, 0.528) . Medical staff working in designated hospitals and key departments were more likely to have anxiety (OR=2.042, 2.702) ; The high fit of the mask to the face and bridge of the nose was a protective factor for the psychological anxiety of medical staff (OR=0.500) . Conclusion: Medical staff show higher stress and anxiety during the epidemic of COVID-19. Psychological intervention should be carried out early, focusing on men, age 31 to 40, medical staff working in designated hospitals and key departments.

SAAMP 2.0: An algorithm to predict genotype-phenotype correlation of lysosomal storage diseases.

Lysosomal storage diseases (LSDs) are a group of genetic disorders, resulting from deficiencies of lysosomal enzyme. Genotype-phenotype correlation is essential for timely and proper treatment allocation. Recently, by integrating prediction outcomes of 7 bioinformatics tools, we developed a SAAMP algorithm to predict the impact of individual amino-acid substitution. To optimize this approach, we evaluated the performance of these bioinformatics tools in a broad array of genes. PolyPhen and PROVEAN had the best performances, while SNP&GOs, PANTHER and I-Mutant had the worst performances. Therefore, SAAMP 2.0 was developed by excluding 3 tools with worst performance, yielding a sensitivity of 94% and a specificity of 90%. To generalize the guideline to proteins without known structures, we built the three-dimensional model of iduronate-2-sulfatase by homology modeling. Further, we investigated the phenotype severity of known disease-causing mutations of the GLB1 gene, which lead to 2 LSDs (GM1 gangliosidosis and Morquio disease type B). Based on the previous literature and structural analysis, we associated these mutations with disease subtypes and proposed a theory to explain the complicated genotype-phenotype correlation. Collectively, an updated guideline for phenotype prediction with SAAMP 2.0 was proposed, which will provide essential information for early diagnosis and proper treatment allocation, and they may be generalized to many monogenic diseases.

Resilience and quality of life among Wenchuan earthquake survivors: the mediating role of social support.

OBJECTIVES: To examine the extent social support mediates resilience and quality of life in Wenchuan earthquake survivors. STUDY DESIGN: Originals. METHODS: Self-report psychological questionnaires, the standard Chinese 12-item Short Form (SF-12v2), the Resilience Scale for Adults (RSA), and the Social Support Rating Scale (SSRS) were used to interview a total of 2080 survivors from 19 counties in the 2008 Wenchuan Earthquake area. A regression analysis was conducted to evaluate the mediating effect of social support on quality of life. RESULTS: Males and individuals with a higher level of education were found to have a better quality of life. The association between resilience and quality of life improved after social support was included, suggesting that at least a part of this association was mediated by the level of social support provided. CONCLUSIONS: This analysis highlighted that the level of resilience and quality of life after an earthquake was associated with the level of social support. This result has clear policy implications, and indicates that more focus needs to be placed on policies that aim for the provision of early mental health intervention and social support to improve the quality of life of earthquake survivors.

[3-Methyladenine alleviates early renal injury in diabetic mice by inhibiting AKT signaling].

OBJECTIVE: To explore the mechanism of 3-methyladenine (3-MA) for alleviating early diabetic renal injury. METHODS: Mouse models of streptozotocin (STZ) -induced diabetes mellitus were randomized into model group and 3-MA treatment group for daily treatments with normal saline and 10 mg/kg 3-MA by gavage for 6 weeks, respectively. Body weight and fasting blood glucose of the mice were recorded every week. After the treatments, the kidneys of the mice were collected for measurement kidney/body weight ratio, examination of glomerular size with PAS staining, and detection of α-SMA and PCNA expressions using Western blotting and immunohistochemistry. SV40 MES 13 cells cultured in normal glucose (5.6 mmol/L) and high glucose (30 mmol/L) were treated with 24.4 mmol/L mannitol and 5 mmol/L 3-MA for 24 h, respectively, and the changes in cell viability and PCNA expression were examined using CCK8 assay and Western blotting. Bioinformatics analysis of the intersecting gene targets of diabetic kidney disease (DKD) and 3-MA was performed, and the results were verified by Western blotting both in vivo and in vitro. RESULTS: In the diabetic mice, treatment with 3-MA produced a short-term hypoglycemic effect, reduced the kidney/body weight ratio and glomerular hypertrophy, and decreased the expressions of α­SMA and PCNA in the renal cortex. In the in vitro study, 3-MA significantly lowered the viability and reduced PCNA expression in SV40 MES 13 cells exposed to high glucose. The results of bioinformatic analysis identified AKT1 as the key gene in the therapeutic mechanism of 3-MA for DKD. Western blotting confirmed that 3-MA inhibited the phosphorylation of AKT and S6 in both the renal cortex of diabetic mice and high glucose-treated SV40 MES 13 cells. CONCLUSION: 3-MA suppresses mesangial cell proliferation and alleviates early diabetic renal injury in mice possibly by inhibiting AKT signaling.

Transmission of megawatt relativistic electron beams through millimeter apertures.

High-power, relativistic electron beams from energy-recovering linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration for this new generation of experimental capabilities is the understanding of the halo associated with these bright, intense beams. In this Letter, we report on measurements performed using the 100 MeV, 430 kW cw electron beam from the energy-recovering linac at the Jefferson Laboratory's Free Electron Laser facility as it traversed a set of small apertures in a 127 mm long aluminum block. Thermal measurements of the block together with neutron measurements near the beam-target interaction point yielded a consistent understanding of the beam losses. These were determined to be 3 ppm through a 2 mm diameter aperture and were maintained during a 7 h continuous run.

Kinetic, isotherm and thermodynamic studies of the adsorption of crystal violet by activated carbon from peanut shells.

The adsorption of crystal violet dye from aqueous solutions onto an activated carbon prepared from peanut shells was analyzed in this study. The effects of particle size, initial concentration, time and temperature on crystal violet removal were studied in batch experiments. Experimental results showed that the adsorption equilibrium was achieved within 100 min for all studied concentrations. Analysis of adsorption results showed that the adsorption isotherms could be well fitted to the Langmuir model. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients for pseudo first-order and second-order kinetic models were calculated and discussed. The results revealed that the adsorption kinetics was in good agreement with the pseudo second-order equation. Thermodynamic parameters such as the change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) have also been determined and it has been found that the adsorption process should be spontaneous, endothermic and physisorption in nature.

Reference values of exhaled nitric oxide in healthy Asian children aged 5 to 18 years.

This study was undertaken to establish reference values of exhaled nitric oxide fraction (F(eNO)) and its determinants in healthy Asian children. 693 healthy Asian children aged 5-18 yrs were assessed using a single-breath online F(eNO) measurement (exhaled flow 50 mL·s(-1)), questionnaires, anthropometric measurements, spirometry and total and specific immunoglobulin (Ig) E. Geometric mean F(eNO) and the upper 95% CI were 13.7 ppb and 49.7 ppb, respectively, for healthy children, and 11.2 ppb and 30.2 ppb, respectively, for those without allergic sensitisation. F(eNO) was positively associated with age, allergic sensitisation, total IgE, ambient nitric oxide, measurement in the afternoon, and drinking water within 1 h before testing, and was negatively associated with weight. In healthy children without allergic sensitisation, age was the single best explanatory variable. The F(eNO) predicted values were 1-2 ppb higher in Asian than in Caucasian children in earlier studies, while the upper 95% CI were 9-10 ppb higher. In conclusion, the upper limits of normal F(eNO) in Asian children depend on age, from 21 ppb in young children to 39 ppb in adolescents. Ethnicity, age, allergic sensitisation, total IgE, ambient nitric oxide, time of testing, drinking water and weight are important determinants.

Exhaled nitric oxide discriminates children with and without allergic sensitization in a population-based study.

BACKGROUND: Fraction of exhaled nitric oxide (FeNO) as a biomarker of airway inflammation in children warrants better clarification. OBJECTIVE: To identify the determinants of FeNO in children and assess the validity of FeNO as a discriminative tool for asthma, rhinitis or allergic sensitization in a population setting. METHODS: Children aged 5-18 years (N=1717) were evaluated using online FeNO measurements, questionnaires, anthropometric measurements, pulmonary function tests and total and specific serum IgE. RESULTS: FeNO levels were age-dependent, with an average increase of 7.4% per year of age. It decreased with increasing body mass index (BMI), estimated at 1.5% decrease per kg/m(2) . Children with allergic sensitization had elevated FeNO independent of allergic symptoms. In the combined analyses of asthma, rhinitis and allergic sensitization, elevated FeNO levels were confined mainly to children having allergic sensitization. After adjusting for allergic sensitization, a significant association between rhinitis and FeNO remained, but no such association was seen with asthma. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of FeNO at the optimum cut-off of 28 p.p.b. for diagnosing asthma were 64.3%, 69.9%, 8.8%, and 97.7%, respectively (area under the ROC curve [AUC] 0.67), and were slightly better for diagnosing allergic asthma: 70.0%, 70.4%, 9.0%, 98.3%, respectively (AUC 0.71). FeNO had modest accuracy in discriminating rhinitis with an AUC value of 0.70, and performed better in discriminating allergic rhinitis (AUC 0.78). FeNO was a robust discriminator of allergic sensitization independent of symptoms at a cut-off of 15.4 p.p.b. (AUC 0.80; sensitivity 72.2%; specificity 71.2%; PPV 76.9%; NPV 65.8%). CONCLUSION AND CLINICAL RELEVANCE: FeNO measurement discriminates children with and without allergic sensitization independent of allergic symptoms. On the other hand, low FeNO levels in children may help exclude allergic asthma but high levels may be caused by allergic sensitization, older age, rhinitis, and lower BMI, in addition to asthma.

Acute pancreatitis in pediatric and adult-onset systemic lupus erythematosus: a comparison and review of the literature.

This study aimed to compare differences of acute pancreatitis between adult- and pediatric-onset systemic lupus erythematosus (SLE) patients and to clarify the risk factors for mortality. Medical records that carried the dual diagnosis of SLE and acute pancreatitis between 1991 and 2005 were reviewed. Forty-eight episodes of acute pancreatitis were identified in 13 pediatric-onset SLE (pSLE) and 27 adult-onset SLE (aSLE) patients. The prevalence was 1.34% overall, with higher prevalence in pSLE (5.22%) compared with aSLE (0.99%) (p < 0.001). The SLEDAI score on presentation of acute pancreatitis was higher in pSLE (mean ± SD: 21.77 ± 13.09) than in aSLE patients (13.37 ± 8.32) (p = 0.05). Eleven patients died during episodes of acute pancreatitis and mortality rate was significantly higher in pSLE than in the aSLE group (53.8% and 14.8%, respectively, p = 0.015). Mortality was associated with concurrent SLE symptoms (p = 0.049), higher SLEDAI score at presentation of acute pancreatitis (p = 0.011), severe acute pancreatitis (p < 0.001), and the presence of complications (p < 0.001). The multivariate logistic regression analysis showed that severity of acute pancreatitis was the most powerful risk factor for mortality in SLE patients with this disease. In summary, our results indicate that acute pancreatitis occurs more frequently, tends to be more severe, and is associated with higher mortality in pSLE patients when compared with aSLE patient.

Improved soil fumigation by Telone C35 using carbonation.

Soil fumigation to control pests and pathogens is an important part of current agricultural practice. A reduction in fumigant emissions is required to ensure worker safety and environment health. A field trial in Florida was conducted to investigate whether carbonating Telone C35™ ((Z)- and (E)-1,3-dichloropropene with 35 % chloropicrin) would improve the delivery of the fumigant to such an extent that the application rate could be decreased without sacrificing efficacy. All treatments were carried out in three replications in a complete block design. The use of carbon dioxide (CO(2)) to carbonate and pressurize Telone C35 provided quicker and deeper distribution initially compared to application by nitrogen gas (N(2)) pressurization. The deeper distribution of Telone C35 components found with CO(2) application may have lowered the initial concentration of Telone C35, but it did not appreciably alter the disappearance rate of the three chemicals, chloropicrin, (Z)- and (E)-1,3-dichloropropene. The faster vertical distribution within the bedded soil of the Telone C35 by CO(2) did enhance volatilization of the active ingredients into the atmosphere compared to volatilization of similar reduced rate applied by N(2) pressurization. However, the cumulative amount volatilized from the carbonated fumigant beds at 75 % application rate was lower than the cumulative amount emitted by full rate of Telone C35 using N(2). The efficacy of the carbonated Telone C35 at a lower application rate was statistically equivalent to that of non-carbonated fumigant using N(2) pressurized injection at a higher application rate, based on weed enumeration and the root-knot nematode galling index.

Clinical characteristics, treatment strategies and oncologic outcomes of primary retroperitoneal tumours: a retrospective analysis in the Chinese population.

INTRODUCTION: Primary retroperitoneal tumours (PRTs) are rare soft tissue tumours originating from the retroperitoneum. Although there has been considerable progress recently in diagnosis and treatment, the overall survival rate has not improved qualitatively. This study aimed to explore the clinical features, therapeutic strategies and prognosis of PRTs. METHODS: Retrospective analysis of clinical data for 121 PRT patients admitted to Peking University Shenzhen Hospital from April 2003 to February 2017. RESULTS: A total of 113 patients underwent surgery and 8 chose nonsurgical palliative treatment. There were 53 males and 68 females (ratio, 1:1.3; average age, 40.75 years), and the average tumour diameter was 9.69(2-40)cm. A total of 104 patients (92.04%) underwent complete resection, 5 (4.42%) underwent palliative resection and 21 (18.58%) underwent combined visceral resection. The pathological diagnosis was benign in 88 cases (72.73%) and malignant in 33 cases (27.27%). A total of 101 patients (83.47%) were followed for an average of 5.82 years. At the end of follow up, the recurrence and survival rates were 2.63% and 93.42% for benign tumours, respectively, and 24.00% and 60.00% for malignant tumours (p<0.01). CONCLUSIONS: Imaging plays important roles in localising and characterising tumours, guiding treatment strategies. Complete tumour resection is key to reducing postoperative recurrence and improving survival. According to the postsurgical pathological results, combinations including radiotherapy, chemotherapy or targeted therapy are beneficial for improving prognosis.

Pediatric lupus in Asia.

Of all patients with systemic lupus erythematosus (SLE), 15-20% are diagnosed during childhood, with disease onset prior to the age of 16 years. Because disease expression in SLE is influenced by environment factors and differs between racial and ethnic groups. The aims of this review were to describe prevalence, clinical manifestations, common infectious complications, and outcome of pediatric-onset SLE in Asia. The prevalence of pediatric-onset SLE was 6.3-19.3 per 100,000 in Asia. The ratio of female to male was 4.7-6.2. The mean age at diagnosis of pediatric-onset SLE was 8.6-13.5 years. The most common clinical features of pediatric-onset SLE in Asia were cutaneous rashes, arthritis, hematological involvement and nephritis. The occurrence of nephritis varies from 29% to 81%. The most common histopathology of lupus nephritis was diffuse proliferative glomerulonephritis (WHO Class-IV) which occurred in 39.4-54% of case of lupus nephritis. Pediatric-onset SLE patients with infections have poor outcomes than uninfected patients. Gram-negative bacilli are the most common microorganisms responsible for bacteremia in Asian patients with SLE. Recurrent major infections predict poorer disease outcome and associated organ damage in pediatric-onset SLE. Improving the survival of SLE patients was reported in Asia in recent decades. The survival was 92% at the age of 5 years, 86% at 10 years and 79% at 15 years in children with SLE in Taiwan in 2008.

Reduced long non-coding RNA PTENP1 contributed to proliferation and invasion via miR-19b/MTUS1 axis in patients with cervical cancer.

OBJECTIVE: Many studies showed that long non-coding RNAs (lncRNAs) may serve as prospective markers for patients with malignant cancers, including cervical cancer (CC). In this study, we mainly investigate the functions of lncRNA PTENP1 in the progression of human CC. MATERIALS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to detect expression levels of PTENP1, miR-19b and MTUS1 in CC tissues, the adjacent tissues and CC cell lines. The correlations between PTENP1 with miR-19b, miR-19b with MTUS1 and PTENP1 with MTUS1 were analyzed. Overall survival (OS) of patients was analyzed using Kaplan-Meier method. Proliferation capacity was measured by CCK-8 assay and the invasion ability in CC cell line was detected by transwell assay. Western blot (WB) assay was performed to measure protein levels of tissues and CC cell lines. Finally, Dual-Luciferase reporter assay was performed to prove the potential binding sites between PTENP1 and miR-19b, miR-19b and MTUS1. RESULTS: We found that PTENP1 was reduced in CC tissues and CC cell lines, which predicted the poor diagnosis of CC patients. MiR-19b was increased in CC tissues, which was negatively correlated with PTENP1 in CC tissues. MTUS1 was reduced in CC tissues, which was negatively correlated with miR-19b and positively correlated within PTENP1 CC tissues. Furthermore, PTENP1 overexpression inhibited cell proliferation ability and invasion capacity in HeLa cells, as well as repressed expressions of Cyclin D1, N-cadherin, and Vimentin. Moreover, Luciferase gene reporter assays verified that miR-19b was a direct target miRNA of PTENP1, and MTUS1 was identified as a direct target of miR-19b. In addition, the inhibited cell proliferation and invasion abilities in HeLa cells with p-PTENP1 were eliminated following with miR-19b mimic transfection. CONCLUSIONS: According to the results, this study showed that PTENP1 was reduced in CC patients and it was a prognostic factor for CC patients. Furthermore, we firstly uncovered that PTENP1 could inhibit cell proliferation and invasion via miR-19b/MTUS1 in CC patients, which uncovered the tumor-suppressive role of PTENP1 in CC and suggested that it might be a potential target for treating human CC.

[Effect of human stromal vascular fraction gel on the treatment of patients with skin depressed scar and its mechanism].

Objective: To observe content of cytokine in human stromal vascular fraction gel (SVF-GEL) and effect of SVF-GEL on biological behaviors of epidermal and dermal cells in vitro and clinical efficacy of SVF-GEL. Methods: (1) SVF-GEL was prepared using liposuction aspirates harvested from females who received abdomen liposuction in author's unit. SVF-GEL (1 mL) and high-glucose Dulbecco's modified eagle medium (DMEM, 1 mL) were respectively cultured for 24 h with high-glucose DMEM containing 10% fetal calf serum, 10 g/L penicillin, and 10 g/L streptomycin, denoted as SVF-GEL group and negative control group, with 6 samples in each group. Content of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) in the supernatant was determined by enzyme-linked immunosorbent assay. (2) A number of 5×10(5) human skin fibroblasts (HSF) and HaCaT cells in logarithmic phase were inoculated and cultured in Transwell chambers for 12 h. All Transwell chambers containing cells were divided into SVF-GEL group (0.5 mL SVF-GEL was added for co-culture) and control group (0.5 mL high-glucose DMEM was added for co-culture), with 9 samples in each group for HSF and HaCaT cells. Scratch assay was performed after culture for 24 h, and residual scratch width was observed at post scratch hour (PSH) 0 (immediately), 24, and 48. Cell migration distance was measured at PSH 24 and 48. After culture for 24, 48, and 72 h, the number of living cell was counted using cell counter. (3) From June 2018 to June 2019, SVF-GEL was applied clinically to treat 15 patients with depressed scars on face, including 2 males and 13 females, aged 19 to 42 years. Survival condition of SVF-GEL and whether complications or not were observed 6 months after surgery. Before surgery and 6 months after surgery, depressed degree, color, and pliability of scar were compared. Vancouver Scar Scale (VSS) was employed to access color, vascularity, and pliability before surgery and 6 months after surgery, and total score was calculated. The number of patients with complete satisfaction or satisfaction was counted six months after surgery. Data were processed with analysis of variance of factorial design, paired samples t test, and Wilcoxon rank sum test. Results: (1) The content of EGF in SVF-GEL group and negative control group was (316.6±12.8) and (3.4±0.6) pg/mL, and the content of VEGF in SVF-GEL group and negative control group was (568.67±12.19) and (4.93±0.16) pg/mL, with statistically significant differences between the two groups (t=48.777, 92.485, P<0.01). (2) Residual scratch widths of HSF and HaCaT in SVF-GEL group and control group were decreased gradually along with time elapse, in which those in SVF-GEL group at PSH 24 and 48 were less than those in control group. At PSH 24 and 48, cell migration distances of HSF and HaCaT in SVF-GEL group were more than those in control group (t(HSF)=-20.304, -43.516, t(HaCaT)=-15.060, -8.684, P<0.01). After culture for 24, 48, and 72 h, the number of living cell of HSF and HaCaT in SVF-GEL group was significantly more than that in control group (t(HSF)=-3.374, -6.809, -18.036, t(HaCaT)=-4.793, -6.028, -8.141, P<0.05 or P<0.01). (3) Six months after surgery, SVF-GEL grafted into patients survived well without complications, and depressed degree of scar ameliorated obviously with lightened pigmentation and softer texture as compared with before surgery. Compared with those before surgery, VSS scores of color, vascularity, and pliability, and total score of 15 patients with depressed scars on face were obviously decreased 6 months after surgery (Z=-2.06, -2.07, -2.07, t=-15.811, P<0.05 or P<0.01). One patient was satisfied with the clinical outcome, and the rest 14 patients were completely satisfied with the clinical outcomes. Conclusions: SVF-GEL contains cytokines EGF and VEGF, which can enhance cell migration ability and proliferation ability of HSF and HaCaT cells and have obvious effects on depressed scars for clinical application.

Temporal and spatial distributions of sediment total organic carbon in an estuary river.

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.

Characterization of the pesticide chlordane in estuarine river sediments.

Sediments are increasingly recognized as both carrier and potential source of contaminants in aquatic environments. This study investigated the characteristics and spatial distribution of total chlordane and its three most abundant compounds, including alpha-chlordane, gamma-chlordane, and trans-nonachlor, in sediments from the Cedar and Ortega rivers, Florida, USA, using geographic information system (GIS)-based kriging analyses and field measurements. Kriging analysis showed that two areas, one from the Cedar River area and the other from the northern end of the Ortega River area, were contaminated. The maximum concentrations of total chlordane, gamma-chlordane, alpha-chlordane, and trans-nonachlor in the sediments were, respectively, 101.8, 20.1, 26.3, and 19.2 microg/kg. A plot of total organic carbon (TOC)-normalized chlordane concentrations showed that effects of grain size on sediment chlordane contamination were negligible. A principal axis analysis further revealed that a linear correlation existed between alpha-chlordane and total chlordane as well as between gamma-chlordane and total chlordane, whereas no correlation existed between trans-nonachlor and total chlordane. Comparison of total chlordane concentration with Florida Sediment Assessment Guidelines showed that the Cedar River and the northern end of the Ortega River had total chlordane concentrations above the probable effect level (4.79 microg/kg), which could pose a potential risk to aquatic life.

Effects of application methods and plastic covers on distribution of cis- and trans-1,3-dichloropropene and chloropicrin in root zone.

This study examined the effects of three application methods (chisel injection, Avenger coulter injection, and drip irrigation) and two plastic films (polyethylene film [PE] and virtually impermeable film [VIF]) on distribution of cis- and trans- 1,3-dichloropropene (1,3-D) and chloropicrin (CP) in a Florida sandy soil after application of Telone C35 or Telone In-Line. Regardless of application method, VIF retained greater amounts of cis- and trans-1,3-D and CP in the root zone with longer residential time than PE. There was better retention of the three compounds in the root zone when applied with the Avenger coulter injection rig than chisel injection, especially in combination with VIF. Distribution of the three compounds in the root zone was less predictable when applied by drip irrigation. Following drip irrigation, more than 50% of the three compounds in the PE and VIF-covered beds was found near the end of the drip tapes in one experiment, whereas the distribution was much more uniform in the root zone in a second experiment. Among the three biologically active compounds, CP disappeared from the root zone more rapidly than cis- and trans-1,3-D, especially in the PE-covered beds.