[Effects of small irrigation facilities on hydrological connectivity of ditches in North Jiangsu Plain, China.] / è‹åŒ—å¹³åŽŸçŒåŒºå°æ°´åˆ©å·¥ç¨‹å¯¹æ²Ÿæ¸ æ°´æ–‡è¿žé€šç»“æž„çš„å½±å“.

Hydrological conditions in the plains irrigation area are complex, which are strongly affected by small irrigation facilities and human management. In this study, the connectivity index of ditch network and the influence index of rural small irrigation facilities were constructed to quantitatively analyze the hydrological connectivity of a typical plain irrigation area, Fudong irrigation area, in north Jiangsu Province. The self-organizing feature map (SOM) analysis method was used to identify the effects of small irrigation facilities on the spatial heterogeneity of ditch network structure connectivity. The results showed that the hydrological structure connectivity differed in different regions of Fudong. The connectivity in the north of the irrigation area was the best, but the worst in the central and southern part of the irrigation area. There were 876 pumps, 633 gates and 2420 culverts in the study area. Without the effects of small irrigation facilities, there were 13 villages with poor hydrological structure connectivity and 48 villages with good and best hydrological structure connectivity. Under the effects of small irrigation facilities, the number of villages with poor connectivity was reduced to 8, while the number of villages with good and best connectivity was increased to 53. Due to the influence of gates and culvert, the hydrological connectivity of 26 villages in Fudong became poor. The hydrological connectivity of 39 villages had been enhanced due to the existence of pump.

[Association between interleukin-8 rs4073 polymorphisms and susceptibility to neonatal sepsis].

OBJECTIVE: To study the association between interleukin-8 (IL-8) rs4073 polymorphisms and susceptibility to sepsis in full-term neonates through a prospective study. METHODS: A total of 50 neonates who were diagnosed with sepsis based on positive blood culture from January to December 2017 were enrolled as the sepsis group. Fifty neonates who had clinical symptoms and negative blood culture were enrolled as the clinical sepsis group. Fifty neonates without infection were enrolled as the control group. Sequencing was used to detect the polymorphisms of IL-8 rs4073. The three groups were compared in terms of the frequencies of genotypes and alleles. A multivariate logistic regression analysis was used to investigate the association of IL-8 rs4073 genotypes with sepsis in full-term neonates. RESULTS: There were significant differences in the frequencies of genotypes and alleles at IL-8 rs4073 among the three groups (P<0.05). The logistic regression analysis showed that a low gestational age and TT genotype at IL-8 rs4073 were risk factors for the pathogenesis of sepsis in neonates (P<0.05). CONCLUSIONS: The full-term neonates with TT genotype at IL-8 rs4073 may be susceptible to sepsis.

Determination of nucleic acids by near-infrared fluorescence quenching of hydrophobic thiacyanine dye in the presence of Triton X-100.

A near-infrared (near-IR) fluorescence quenching method was developed for the determination of nucleic acids in aqueous solution by using a cationic heptamethylene thiacyanine as a probe. The near-IR cationic cyanine showed maximum excitation and emission wavelengths at 800 and 825 nm, respectively, in the presence of Triton X-100; the fluorescence of the cyanine could be greatly quenched by DNA. The calibration graphs were linear over the range of 10-400 ng/mL for CT (calf thymus) DNA and over the range 5-400 ng/mL for FS (fish sperm) DNA under optimal conditions. The corresponding detection limits were 5.2 ng/mL for CT DNA and 2.5 ng/mL for FS DNA. The relative standard deviation (n = 8) was 3.1% for 75 ng/mL CT DNA and 2.2% for 75 ng/mL FS DNA, respectively. Preliminary research showed that the fluorescence quenching might be ascribed to the formation of dye aggregate facilitated by DNA.

Fluorescence enhancement method for measuring anionic surfactants with a hydrophobic cyanine dye.

A novel fluorimetric method based on use of a hydrophobic cationic cyanine dye has been developed for determination of the anionic surfactant sodium dodecylbenzenesulfonate (DBS). The method is based on the enhancement effect of DBS on the fluorescence of the hydrophobic cyanine dye 2-[-4'-chloro-7'-(1"-ethyl-3",3"-dimethylindolin-2"-ylidene)-3',5'-(propane-1"',3"'-diyl)-1',3',5'-heptatrien-1'-yl]-1-ethyl-3,3-dimethyl-3 H-indolium iodide. Under the optimum conditions the extent of fluorescence enhancement is proportional to the concentration of DBS in the range 0.05-5.0 mg L(-1); the detection limit is 0.014 mg L(-1). The relative standard deviation for 0.35 mg L(-1) DBS was 1.1% (n=10). The proposed method, which avoided use of toxic solvents and tedious solvent-extraction, and was applied to the determination of DBS in natural water with recoveries between 99.9 and 107%. Preliminary research shows that the fluorescence enhancement is due to the formation of a dye aggregate facilitated by DBS.

Near-infrared fluorimetric determination of nucleic acids by shifting the ion-association equilibrium between tetracarboxy aluminum phthalocyanine and tetra-N-hexadecylpyridiniumyl porphyrin.

A new method was developed for determination of micro amounts of nucleic acids based on near-infrared (near-IR) fluorescence recovery, employing a two-reagent system which is composed of an anionic tetracarboxy aluminum phthalocyanine (AlC(4)Pc) and a cationic tetra-N-hexadecylpyridiniumyl porphyrin (TC(16)PyP). The fluorescence of the AlC(4)Pc, with the maximum emission wavelength at 701nm, could be quenched by TC(16)PyP at its proper concentration, but recovered by adding nucleic acids. Under optimal conditions, the recovered fluorescence is proportional to the concentration of nucleic acids. The calibration graphs are linear over the range of 1-200ngmL(-1) for fish sperm DNA (FS DNA) and 2-400ngmL(-1) for calf thymus DNA (CT DNA). The corresponding detection limits are 0.59ngmL(-1) for FS DNA and 0.82ngmL(-1) for CT DNA, respectively. Four synthetic and three real nucleic acid samples were determined with satisfactory results.

Application of L-cysteine-capped nano-ZnS as a fluorescence probe for the determination of proteins.

Nanometer-sized L-cysteine-capped ZnS particles have been synthesized and used as a fluorescence probe to investigate the effect of proteins on fluorescent intensity. With Delta lambda=190 nm, maximum and constant synchronous fluorescence enhancement was produced at 267 nm and pH 5.12 in the presence of proteins. A highly sensitive synchronous fluorescence method for the rapid determination of proteins has been developed. Under optimum conditions, calibration graphs are linear over the range 0.03-8.0 microg mL(-1) for bovine serum albumin (BSA), 0.01-6.0 microg mL(-1) for human serum albumin (HSA), 0.05-8.0 microg mL(-1) for gamma-globulin (gamma-G), and 0.04-4.0 microg mL(-1) for ovalbumin, respectively. The relative standard deviations of seven replicate measurements were 1.75% for 1.0 microg mL(-1) BSA, 1.90% for 1.0 microg mL(-1) HSA, 1.65% for 1.0 microg mL(-1) gamma-G, and 2.32% for 1.0 microg mL(-1) ovalbumin.