Detection and Quantification of Biological and Physiochemical Parameters in Porous Media

Three studies were conducted in this thesis, and all were related to measurement of biological and physiochemical parameters in porous media. The first study focused on the detection of biological parameter, and investigated the effects of cerium oxide nanoparticles on soil enzyme activity. Different concentrations of soil-NP mixture were applied, and exposure time length in addition to the harvest events were considered during the experiments. The second study focused on the quantification of physical parameter, and revealed water saturation percentage profiles during infiltration process along the preferential flow fingers. Two microbial exudates, catechol and riboflavin, with varying concentrations were applied to the flow experiments. Light transmission method was utilized to acquire information of light intensity, which was later converted to water saturation percentage. The third study focused on the measurement of physiochemical parameters, and evaluated the pH and dissolved oxygen concentration gradients in 2D tank sand system. Optical image technique was used to obtain data, and emitted fluorescence from the sensor foils were captured by the camera

Movement of Cryptosporidium parvum Oocysts through Soils without Preferential Pathways: Exploratory Test

Groundwater contamination by oocysts of the waterborne pathogen Cryptosporidium parvum is a significant cause of animal and human disease worldwide. Although research has been undertaken in the past to determine how specific physical and chemical properties of soils affect the risk of groundwater contamination by C. parvum, there is as yet no clear conclusion concerning the range of mobility of C. parvum that one should expect in field soils. In this context, the key objective of this research was to determine the magnitude of C. parvum transport in a number of soils, under conditions in which fast and preferential transport has been successfully prevented. C. parvum oocysts were applied at the surface of different soils and subjected to artificial rainfall. Apparently for the first time, quantitative PCR was used to detect and enumerate oocysts in the soil columns and in the leachates. The transport of oocysts by infiltrating water, and the considerable retention of oocysts in soil was demonstrated for all soils, although differences in the degree of transport were observed with soils of different types. More oocysts were found in leachates from sandy loam soils than in leachates from loamy sand soils and the retention of oocysts in different soils did not significantly differ. The interaction of various processes of the hydrologic system and biogeochemical mechanisms contributed to the transport of oocysts through the soil matrix. Results suggest that the interplay of clay, organic matter, and Ca2+ facilitates and mediates the transfer of organic matter from mineral surfaces to oocysts surface, resulting in the enhanced breakthrough of oocysts through matrices of sandy loam soils compared to those of loamy sand soils. Although the number of occysts that penetrate the soil matrix account for only a small percentage of initial inputs, they still pose a significant threat to human health, especially in groundwater systems with a water table not too distant from the soil surface. The results of the research demonstrate a critical need for the simultaneous study of the interaction of various processes affecting oocysts transport in the subsurface, and for its expansion into complex systems, in order to obtain a coherent picture of the behavior of C. parvum oocysts in soils

A Temperature Drift Compensation Method for Pulsed Eddy Current Technology

Pulsed eddy current (PEC) technology is another important non-contact nondestructive testing technology for defect detection. However, the temperature drift of the exciting coil has a considerable influence on the precision of PEC testing. The objective of this study is to investigate the temperature drift effect and reduce its impact. The temperature drift effect is analyzed theoretically and experimentally. The temperature drift effect on the peak-to-peak values of the output signal is investigated, and a temperature compensation method is proposed to reduce the effect of temperature variation. The results show that temperature drift has a negative impact on PEC testing and the temperature compensation method can effectively reduce the effect of temperature drift

Fate and transport of Cryptosporidium parvum oocysts in repacked soil columns: Influence of soil properties and surfactant

Abstract A series of laboratory experiments was performed to investigate the transport and retention of viable C. parvum oocysts in soil columns homogeneously packed with loamy sand soils (Lewiston and Greenson series) and sandy loam soils (Sparta and Gilford series), and under hydrologic conditions involving the presence of an anionic surfactant—Aerosol 22 in artificial rainfall. To characterize the effect of surfactant on the mobility of C. parvum oocysts in the soils used in this study, these results were compared with previous laboratory‐scale column experiments of a previous study using soils contaminated with oocysts, under conditions identical to those described here except for the absence of the surfactant in the percolating water. Quantitative polymerase chain reaction was used for the detection and quantification of C. parvum oocysts in soil leachates to assess their breakthrough and in soil matrices to characterize their spatial distribution. Alterations in the rate and extent of transport of C. parvum oocysts were discerned per the physicochemical parameters analyzed—soil types, soil chemistry, and surfactant—and resulted in either the enhancement or hinderance of C. parvum oocysts adsorption to surfaces, and their movement in soils. In the case of loamy sand soils, the transport of C. parvum oocysts through the soil matrices increased with the application of surfactant for Sparta series and remained at a similar level for Gilford series. Regarding sandy loam soils, the movement of C. parvum oocysts through the soil matrices increased for Greenson series and decreased for Lewiston series with the application of surfactant

New Naphthalene Derivatives from the Mangrove Endophytic Fungus <i>Daldinia eschscholzii</i> MCZ-18

Five new naphthalene derivatives dalesconosides A–D, F (1–4, 6), a known synthetic analogue named dalesconoside E (5), and eighteen known compounds (7–24) were isolated from Daldinia eschscholzii MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant Ceriops tagal. Differing from previously reported naphthalenes, compounds 1 and 2 were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds 1, 3, 13–17 and 19 showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (Enterococcus faecalis, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans); especially, 1, 16 and 17 were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure−activity relationships for the naphthalene derivatives

Sohlh1 and Lhx8 are prominent biomarkers to estimate the primordial follicle pool in mice

Abstract Efficient evaluation of the primordial follicle pool (PFP) of mammalian models is an essential subject in biomedical research relating to ovarian physiology and pathogenesis. Our recent study has identified a gene signature including Sohlh1, Nobox, Lhx8, Tbpl2, Stk31, Padi6, and Vrtn strongly correlated with ovarian reserve by using bioinformatics analysis. Aimed to investigate the validity of these candidate biomarkers for evaluating the PFP, we utilized an OR comparison model to decode the relationship between the numbers of PFP and candidate biomarkers in the present study. Our results suggest that these biomarkers Sohlh1, Nobox, Lhx8, Tbpl2, Stk31, Padi6, and Vrtn possess independent potential to evaluate the number of the PFP. And the combination of Sohlh1 and Lhx8 can be used as the optimal biomarkers for rapid assessment of the PFP in the murine ovary. Our findings provide a new perspective for evaluating the PFP of the ovary in animal studies and the clinic

Hydrogen gas promotes the adventitious rooting in cucumber under cadmium stress.

Hydrogen gas (H2) plays an important role in plant development and stress responses. Here, cucumber (Cucumis sativus L.) explants were used to investigate the roles of H2 in adventitious root development under cadmium (Cd) stress and its physiological mechanism. The results showed that hydrogen-rich water (HRW) promoted adventitious rooting under Cd stress and 50% HRW obtained the maximal biological response. Compared with Cd treatment, HRW + Cd treatment significantly reduced the content of malondialdehyde (MDA), hydrogen peroxide (H2O2), superoxide radical (O2-), thiobarbituric acid reactive substances (TBARS), ascorbic acid (AsA) and reduced glutathione (GSH), as well as relative electrical conductivity (REC), lipoxygenase (LOX) activity, AsA/docosahexaenoic acid (DHA) ratio, and GSH/oxidized glutathione (GSSG) ratio, while increasing DHA and GSSG content. HRW + Cd treatment also significantly increased in the activity and related gene expression of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR). Additionally, HRW + Cd treatment increased the contents of osmotic adjustment substances, as well as the activities of peroxidase (POD) and polyphenol oxidase (PPO), while significantly decreasing indoleacetic acid oxidase (IAAO) activity. In summary, H2 could induce adventitious rooting under Cd stress by decreasing the oxidative damage, increasing osmotic adjustment substance content and regulating rooting-related enzyme activity

miR398 Attenuates Heat-Induced Leaf Cell Death via Its Target CSD1 in Chinese Cabbage

Previous research has shown that miR398 contributed to plant thermotolerance by silencing its target gene COPPER/ZINC SUPEROXIDE DISMUTASE1 (CSD1) in Arabidopsis thaliana. However, the phylogenesis of miR398 and CSD1 in Brassica crop and their role in regulating leaf cell death under heat stress remains unexplored. Here, we characterized the homologous genes of miR398a and CSD1 in Brassica rapa ssp. pekinensis (Chinese cabbage) and found miR398a abundance was accumulated under heat stress (38 °C and 46 °C for 1 h) in Chinese cabbage, while the expression level of its targets BraCSD1-1 and BraCSD2-1 were downregulated. To further explore their role in heat response, we constructed the transgenic plants overexpressing artificial miR398a (aBra-miR398a), Bra-miR398a target mimic (Bra-MIM398a), and BraCSD1-1 in Chinese cabbage for genetic study. Under high temperatures, p35S::aBra-miR398a lines reduced the areas of leaf cell death and delayed the leaf cell death. By contrast, p35S::Bra-MIM398a and p35S::BraCSD1-1 plants enlarged the areas of leaf cell death and displayed the earliness of leaf cell death. Finally, we found that the expression level of stress-responsive genes BraLEA76, BraCaM1, BraPLC, BraDREB2A, and BraP5CS increased in transgenic plants overexpressing aBra-miR398a, which may contribute to their resistance to heat-induced leaf cell death. Taken together, these results revealed the function of Bra-miR398a in attenuating leaf cell death to ensure plant thermotolerance, indicating that the miR398-CSD1 module could be potential candidates for heat-resistant crop breeding

Identification of a high threshold value of serum ferritin in the diagnosis of hemophagocytic lymphohistiocytosis in hospitalized children in China

IDENTIFICATION OF A HIGH THRESHOLD VALUE OF SERUM FERRITIN IN THE DIAGNOSIS OF HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS IN HOSPITALIZED CHILDREN IN CHINA Journal of laboratory medicine (Rights reserved) (-) Identification of a high threshold value of serum ferritin in the diagnosis of hemophagocytic lymphohistiocytosis in hospitalized children in China / Huang, Yanlong (CC BY) (-