Evaporation ponds as a drainwater disposal management option

Constructed evaporation ponds are being utilized for disposalof saline subsurface drainage waters in San Joaquin Valley,California. These terminal evaporation ponds are located inhydrologically closed basins and/or regions with no surfacedrainage out of the valley. The saline drainwaters disposedinto the ponds are sodium-sulfate or sodium-sulfate-chloridetype waters and upon desiccation produces mirabilite andhalite. The drainwaters contain excessive levels of traceelements from geochemical origins. The trace element of mostconcern, is selenium because it bioaccumulates in the aquaticfood chain and causes death and deformity of waterbirdsattracted to the pond environment. At the present, the onlyeconomic drainwater disposal option in the southern. portionof the valley is evaporation ponds. The operation of theseponds is heavily regulated by waste discharge requirements toreduce and mitigate wildlife impacts. A case study onevaporation ponds and bird usage from a drainage districtillustrates the extensive monitoring and mitigation required.The prognosis is evaporation basins will be needed for theforeseeable future unless breakthroughs occur in economic andeffective drainwater treatment and drainwater reuseoptions.     

不同结构Gemini抗菌剂的抗菌活性

以十二烷基三甲基溴化铵(DTAB)为对照,用最低抑菌浓度法(NIC)评价了几种结构相似的Gemini抗菌剂(C1、C2、C3及C4)的抗菌活性.结果表明,4种Gemini抗菌剂与DTAB相比,均具有较好的抗菌活性,其中C2对金黄色葡萄球菌和大肠杆菌的MIC分别为1.5μg·L-1和3.91μg·L-1;C4对白假丝酵母的MIC为3.91μg·L-1.还发现结构相似的Gemini抗菌剂,其主链、总链及烷基的链长越长,抗菌活性越高;且烷基链为带氟碳链者抗菌活性较碳氢链高.     

Short Communication Actual cation exchange capacity in lignite containing pyritic mine soils

The actual cation exchange capacity (CEC_act) in sandy mine soils from Tertiary sediments increases with the lignite contents of the substrates. Therefore, lignite is important for nutrient storage and availability in these soils. Base saturation varies over a wide range of 4 — 100% according to soil pH. For the determination of CEC_act, the high contents of soluble salts typical for these substrates have to be considered for reliable results.     

高水基润滑添加剂Bi／Zn—DTP的研究

合成二烷基二硫代磷酸铋素Ｂｉ－ＤＴＰ及锌直Ｚｎ－ＤＴＰ，采用某种助溶剂将它们用于高水基体系，通过四球摩擦磨损试验及磨削应用试验，进行润滑性能评价。     

Liver function in cats with hyperthyroidism before and after 131I therapy

BACKGROUND: The clinical significance of high serum concentration or activity of markers of liver damage in cats with hyperthyroidism is unknown. OBJECTIVE: To evaluate serum markers of liver function and damage, and ultrasonographic changes in cats with hyperthyroidism and with high liver enzymes, and to determine if abnormalities resolve after treatment with 131I. ANIMALS: Nineteen cats with hyperthyroidism (15 with high serum activities of liver enzymes) and 4 age-matched healthy control cats. METHODS: Serum bile acids, albumin, ammonia, cholesterol, and blood urea nitrogen concentrations, and activities of liver-derived enzymes, and blood glucose concentrations were measured before and after 131I therapy. These values were compared with those of cats that were euthyroid. In addition, gross liver parenchymal changes detected by abdominal ultrasonographic examination, before and after 131I therapy were evaluated. RESULTS: High serum liver enzyme activities were not associated with abnormalities in hepatic parenchyma and liver functional variables, regardless of the degree of increase. Serum liver enzyme activities return to normal after control of hyperthyroidism with 131I therapy. Cats with hyperthyroidism have a significantly higher serum fasting ammonia concentration than cats who were euthyroid (P = .019). Cats with hyperthyroidism also have significantly lower serum cholesterol (P = .005) and glucose (P = .002) concentrations before compared with after 131I therapy. Nine of 19 cats with hyperthyroidism had trace ketonuria. CONCLUSIONS AND CLINICAL IMPORTANCE: These results demonstrate that extensive examination for hepatobiliary disease in most cats with hyperthyroidism is unnecessary.     

Effects of leptin on BSEP protein expression and signaling pathway in HepG2 cells

AIM: To investigate the effects of leptin on the expression of bile salt export pump (BSEP) and signaling pathway in human hepatocellular carcinoma cell line HepG2. METHODS: HepG2 cells were cultured in vitro. Leptin at concentrations of 10^-8, 10^-7 and 10^-6 mol/L was used as a stimulating factor. The protein levels of adenosine monophosphate-activated protein kinase alpha subunit (AMPKa), phosphorylated AMPKa (p-AMPKa) and BSEP in the HepG2 cells at 24 h, 48 h and 72 h were detected by Western blotting. The optimal culture time and leptin concentration were selected, and compound C at concentration of 10 μmol/L was added to this group. The protein expression of BSEP was detected by Western blotting. RESULTS: Intervention of HepG2 cells with leptin for 72 h increased the protein expression of AMPKa gradually in a concentration-dependent manner, and leptin at concentration of 10^-6 mol/L induced the strongest AMPKa expression (P<0.01). Intervention of HepG2 cells with leptin for 24 h increased the phosphorylation level of AMPKa gradually in a dose-dependent manner (P<0.01). The effect of leptin on the increase in the protein expression of p-AMPKa was also in a time-dependent manner (P<0.01). After intervention with different concentrations of leptin for 24 h, the protein expression of BSEP in the HepG2 cells was gradually increased by the stimulation of leptin in a concentration- and time-dependent manner (P<0.01). Compared with NC group, the protein expression of BSEP in 10^-6 mol/L leptin group and 10^-6 mol/L leptin+10 μmol/L compound C group was increased at 72 h (P<0.01), and that in 10^-6 mol/L leptin+10 μmol/L compound C group was lower than that in 10^-6 mol/L leptin group at 72 h (P<0.01). CONCLUSION: Leptin promotes the protein expression of BSEP in HepG2 cells by leptin-AMPK-BSEP signaling pathway. Leptin promotes the increases in AMPKa protein and the level of phosphorylation of AMPKa in HepG2 cells.     

水分调控对盐碱地土壤盐分与养分含量及分布的影响

为给新疆地区盐碱地开发利用提供合理的灌溉指导,该文研究了滴灌条件下内陆干旱区重度盐碱地水分调控对土壤盐分与养分的影响,2008-2010年连续3 a设置了滴头正下方20 cm处5个土壤基质势下限控制灌溉:-5 kPa(S1)、-10 kPa(S2)、-15 kPa(S3)、-20 kPa(S4)和-25 kPa(S5),每个处理重复3次,按随机区组布置,于2008年试验前和2008-2010年试验后采集土壤样品(0~5、5~10、10~20、20~30和30~40 cm),测定土壤盐分(电导率、钠吸附比)以及土壤养分(速效N、P、K,全N、全P,有机质)含量。结果表明:3 a试验结束后,各处理0~40 cm土层土壤电导率与钠吸附比均显著(p0.05)降低,其中-5 kPa(S1)处理土壤电导率降至5.3 dS/m,降低幅度最大,为89%;速效N、P、K,全N、全P以及有机质含量较试验前均有显著升高,升高幅度均在20%以上,且与土壤基质势下限成正比。各处理速效养分均在滴头周围形成累积区,且随与滴头距离的增加而减少,养分全量与有机质含量在土壤剖面垂直分布差异显著。各处理土壤C/N均较第1年播种前降低,且降低率(4.3%~13.5%)随土壤基质势下限的降低而升高。综合土壤盐分的淋洗效果以及土壤养分的改良程度,滴头正下方20 cm处土壤水基质势控制下限-5 kPa可以作为内陆干旱区前3 a盐碱地水分调控的指导灌溉制度。     

Foliar Iron Fertilization: A Critical Review

Application of foliar iron (Fe) sprays is a common means of correcting Fe deficiency of agricultural crops. However, variable plant responses to iron sprays, ranging from no effect to defoliation, have often been described in the Fe-fertilization literature. Knowledge is still limited concerning the mechanisms of penetration of a leaf-applied, Fe-containing solution and the role of Fe in the leaf. The complex and multi-disciplinary character of the factors determining the effects of Fe sprays hinder the development of suitable foliar fertilization strategies, applicable under variable local conditions and for different plant types. This review describes some key factors involved on the process of penetration of a leaf-applied, Fe-containing solution before briefly analyzing the available foliar Fe-fertilization literature. Iron chemistry, leaf penetration, and plant-nutrition principles will be merged with the aim of clarifying the constraints, opportunities, and future perspectives of foliar Fe sprays to cure plant Fe deficiency.