Bioavailability of PCDDs and PCDFs on fly ash after semi-chronic oral ingestion by guinea pig and syrian golden hamster

Groups of guinea pigs and syrian golden hamster (n = 5) were fed 2.5% HCL pre-treated fly ash from the electrostatic precipitator of a municipal incinerator during one, two and three months, respectively, in the diet. The livers were analyzed for tetra-, penta- and hexa-chlorinated dibenzo(p)dioxins (PCDDs) and dibenzofurans (PCDFs).In the livers of the hamsters 2,3,7,8-substituted PCDDs and PCDFs were the major isomers retained. In the livers of the guinea pigs 2,3,7,8 substituted PCDDs and PCDF congeners were retained, but also a number of otherwise substituted PCDFs. These other PCDF congeners included some having a 2,3,6,7 or alternate chlorine substitution pattern. Those congeners retained in the livers were generally below 5% of the group dose. The PCDF congener which had the highest retention in the livers of guinea pig was 1,2,3,7,8-PnCDF, 11.3% after 95 days. In the livers of the hamsters highest retention was found for 2,3,4,7,8-PnCDF, 8.4% after 95 days. For most 2,3,7,8-substituted PCDDs and PCDFs the retention in the livers of the guinea pigs and hamsters was not significantly different during the whole period, which could indicate a bioconcentration approaching a linear relationship to the administered dose. Constant relative concentrations in the livers were found for the 2,3,7,8- substituted penta- and hexa-chlorinated PCDDs and PCDFs in both species during the three time periods.     

Nutritional assessment of transgenic sweetpotato on body weight, lipid, and protein status in hamsters

The objectives of the present study were to evaluate the nutritional quality of genetically modified sweetpotato (genotype PI318846-3) on growth, lipid metabolism, and protein metabolism of hamsters. Three different diets made with transgenic and nontransgenic sweetpotato protein flour including a control diet with casein were fed to male Golden Syrian hamsters for 28 days. The protein efficiency ratio (1.35 +/- 0.01) of the transgenic sweetpotato protein diet was significantly higher (p<0.05) than the nontransgenic sweetpotato and control diets. Plasma albumin and plasma total protein concentrations of hamsters fed the sweetpotato diets were significantly lower (p<0.05) than that of the control. The casein diet (control) produced hypercholesterolemia in hamsters, whereas sweetpotato diets maintained lower plasma and liver total and LDL-cholesterol concentrations in hamsters. Sweetpotatoes contain less amount of protein to maintain the normal animal growth; however, transgenic sweetpotato has good quality protein that supported the growth of hamsters better than nontransgenic sweetpotato.     

NUTRITIONAL ASSESSMENT OF TRANSGENIC SWEETPOTATO ON BODY WEIGHT,LIPID, AND PROTEIN STATUS IN HAMSTERS

The objectives of the present study were to evaluate the nutritional quality of genetically modified sweetpotato (genotype PI318846-3) on growth, lipid metabolism, and protein metabolism of hamsters. Three different diets made with transgenic and nontransgenic sweetpotato protein flour including a control diet with casein were fed to male Golden Syrian hamsters for 28 days. The protein efficiency ratio (1.35±0.01) of the transgenic sweetpotato protein diet was significantly higher (p<0.05) than the nontransgenic sweetpotato and control diets. Plasma albumin and plasma total protein concentrations of hamsters fed the sweetpotato diets were significantly lower (p<0.05) than that of the control. The casein diet (control) produced hypercholesterolemia in hamsters, whereas sweetpotato diets maintained lower plasma and liver total and LDL-cholesterol concentrations in hamsters. Sweetpotatoes contain less amount of protein to maintain the normal animal growth; however, transgenic sweetpotato has good quality protein that supported the growth of hamsters better than nontransgenic sweetpotato.     

BIOAVAILABILITY OF CALCIUM FROM SWEETPOTATO AND SOY FLOUR SUPPLEMENTED DIETS IN HAMSTERS

The bioavailability of calcium from two varieties of sweetpotatoes and supplementation of sweetpotatoes with soy flour was investigated in hamsters using plasma calcium concentration and femur calcium content as indicators. Five different diets were fed to five groups of animals for 28 days. There was no significant difference in plasma calcium concentrations of hamsters in all the diet groups. However, the femur calcium content of hamsters with transgenic sweetpotato flour (TSPF) and parent nontransgenic (from which transgenic was produced) sweetpotato flour (NTSPF) diets was significantly higher than that of the transgenic sweetotato flour supplemented with soy flour (TSPF+SF) and parent nontransgenic sweetpotato flour supplemented with soy flour (NTSPF+SF) diets. The relative bioavailability of calcium from the control (100%), TSPF+SF (30%), NTSPF+SF (23%), TSPF (57%) and NTSPF (46%) indicated that sweetpotatoes could be the better source of calcium, however, supplementation with soy flour might reduce the bioavailability of calcium.     

Bioavailability of calcium from sweetpotato and soy flour supplemented diets in hamsters

The bioavailability of calcium from two varieties of sweetpotatoes and supplementation of sweetpotatoes with soy flour was investigated in hamsters using plasma calcium concentration and femur calcium content as indicators. Five different diets were fed to five groups of animals for 28 days. There was no significant difference in plasma calcium concentrations of hamsters in all the diet groups. However, the femur calcium content of hamsters with transgenic sweetpotato flour (TSPF) and parent nontransgenic (from which transgenic was produced) sweetpotato flour (NTSPF) diets was significantly higher than that of the transgenic sweetotato flour supplemented with soy flour (TSPF + SF) and parent nontransgenic sweetpotato flour supplemented with soy flour (NTSPF + SF) diets. The relative bioavailability of calcium from the control (100%), TSPF+SF (30%), NTSPF+SF (23%), TSPF (57%) and NTSPF (46%) indicated that sweetpotatoes could be the better source of calcium, however, supplementation with soy flour might reduce the bioavailability of calcium.     

Experimental Studies of the Conditions of Exposure to Carcinogens for Lung Cancer Induction

A method is described for the experimental induction of lung cancer. Syrian golden hamsters, receiving repeated intratracheal administrations of benzo[a]pyrene in particulate form carried by an inert dust, develop a high incidence of bronchogenic carcinoma. The conditions of exposure to the carcinogen, involving penetration and retention of carcinogen particles in lung tissues with the dust, are of prime imvortance in the determination of the results. Instillations of the same carcinogen in other media did not induce lung tumors. The relative importance of the identification of carcinogenic materials in air pollution and of the conditions of exposure in the origin of lung cancer is discussed.     

Biochemical,hematological, and pathological related healing effects of Elaeagnus angustifolia hydroalcoholic extract in 5-fluorouracil-induced oral mucositis in male golden hamster

Oral mucositis (OM) is one of the cancer chemotherapy-related side effects which can affect the quality of life of affected patients. This study was designed to investigate the healing effect of Elaeagnus angustifolia in 5-flurouracil (5-FU)-induced OM in golden hamster. Fifty-six adult male golden hamsters received three intraperitoneal injections of 5-FU at a dose of 60 mg/kg on days 0, 5, and 10. The cheek pouch mucosa was scratched superficially under local anesthesia. Then, two horizontal scratches were made across the everted cheek pouch on days 3 and 4. All treatments were started on day 12 for equal number of animals in control group with no treatments, gel base group that was treated with carboxy methyl cellulose as gel base which used in preparation of the topical gel, topical gel group that used gel containing 10% hydroalcoholic extract of E. angustifolia (HEEA) topically, and dietary group which was treated with 300 mg/kg HEEA. At 2 and 5 days after treatment, blood and pouch tissue sampling were done and analyzed for blood composition, tissue malondialdehyde (MDA) level, and myeloperoxidase (MPO) and superoxide dismutase (SOD) activities plus histopathological evaluations. Both topically and orally HEEA-treated groups showed a significant relief in OM compared to the control and base gel groups. However, the systemic form had higher efficiency in some parts especially decreasing the MPO (0.27 ± 0.17 vs. 0.56 ± 0.17 IU/L) and increasing SOD (6.46 ± 0.15 vs. 5.36 ± 0.18 IU/L) activities in pouch tissue in comparison to topical form mostly at 5 days after treatment. It seems that hydroalcoholic extract of E. angustifolia can be used as an appropriate drug choice for the treatment of oral mucositis based on its healing stimulatory and anti-inflammatory properties.

     

Plant uptake and in-soil degradation of PCB-5 under varying cropping conditions

A 60-d greenhouse experiment was conducted to investigate the uptake and in-soil degradation of PCB-5 under single cropping and intercropping conditions involving three crop plant species: pumpkin, soybean and corn. Volatilization of PCB-5 from the soil surface was also tested. The results show that while uptake of PCB-5 by the test plant species is possible and the root concentration of PCB-5 had a control on the upward transport of PCB-5 to the above-ground portion of the plants, the PCB-5 extracted by the plants mainly accumulated in the root materials. Phytoextraction contributed insignificantly toward the loss of the soil-borne PCB-5. Volatilization of PCB-5 from the soil was recorded but it appeared that this did not result in a marked loss of PCB-5 in the bulk soil though it might cause remarkable removal of PCB-5 in a thin layer of the topsoil (1 mm). It is likely that the in-soil biodegradation contributed markedly to the observed reduction in soil-borne PCB-5. The in-soil biodegradation of PCB-5 was significantly enhanced under intercropping conditions, which appeared to be related to increased microbial activities, particularly bacterial activities. The soil residual PCB-5 was correlated with the activity of the following enzymes: catalase (CAT), polyphenol oxidase (PPO) and peroxidase (POD).     

沼泽红假单胞菌W12对活性黑5的厌氧脱色和降解作用

从处理印染废水的厌氧移动床生物膜反应器（moving bed biofilm reactor, MBBR）中分离到一株具有高效脱色活性的沼泽红假单胞菌W12。经实验确定W12对活性黑5（reactive black 5,RB5）脱色的适宜条件为：pH＜10;有光照;谷氨酸盐或乳酸盐作为碳源,当乳酸钠为碳源时浓度应＞500 mg/L;盐度不超过5％;RB5浓度不大于700 mg/L。紫外可见光谱扫描结果表明,RB5的脱色和降解过程生成芳香胺类化合物,这些中间产物可进一步降解。此外发现,RB5诱导生成的胞外代谢物能提高W12的脱色活性。     

Fathead minnow (Pimephales promelas) embryo to adult exposure to decamethylcyclopentasiloxane (D5)

The cyclic siloxane decamethylcyclopentasiloxane (D5) is a high production volume chemical which has recently been assessed under the Canadian Chemicals Management Plan (CMP). Cyclic volatile methyl siloxanes (cVMS) are one of the challenge substances in the CMP batches. To provide toxicity and growth information on a species of relevance to the Canadian environment, we assessed D5 in a fathead minnow (Pimephales promelas) embryo to young adult assay. The test was 65 d in length, and exposed fathead minnow eggs to juveniles until near maturity (60 d post-hatch). The D5 concentrations in flow-through fish exposure aquaria were about one-third of nominal D5 concentrations. Fathead minnows were exposed to 0.25, 0.82, 1.7, 3.6, and 8.7 μg L⁻¹ D5. During the exposure of fathead minnows to D5 there were few effects seen. Egg hatching and larval fish survival and growth were normal. Juvenile fish survival and growth were good in all environmentally-relevant concentrations of D5, and were similar to control fish. The two highest D5 concentrations (8.7 μg L⁻¹ and 3.6 μg L⁻¹, mean measured D5) increased the condition factors of fathead minnows compared to water control and DMSO control fish. Although there were few effects of D5 in our fathead minnow study, the compound was taken up and stored in fish bodies over the 65-d exposure. The bioconcentration factor for D5 in fathead minnows was 4450, for the lowest environmentally-relevant D5 exposure water concentrations, and 4920 for all D5 exposure concentrations tested.     

Bioaccumulation and elimination of tetrachlorobenzyltoluene (TCBT) by the rat and by fish

A comparative study has been made of the bioaccumulation and elimination by fish and the rat of (i) tetrachlorobenzyltoluene (TCBT), a substance recently proposed as a substitute for polychlorobiphenyl (PCB), and (ii) DP5, a pentachlorobiphenyl mixture (PCB-5 C1).

The study relating to fish (Brachydanio Rerio) comprised a 30-day accumulation period followed by a 30-day elimination period. Nominal concentrations of TCBT and PCB-5 C1, respectively, in the water, were 1mg/litre in both cases.

The study relating to the rat comprised a 90-day treatment period followed by a 30-day elimination period. The animals were exposed by oral (gavage) to doses of 0, 5, 30, and 200 mg/kg/day in the case of TCBT and to the single dose of 5 mg/kg/day in the case of PCB-5 Cl.

Concentrations of TCBT and PCB-5 Cl in rat liver and fats, in whole body tissues of fish and in water were measured by gas chromatography, using an electron capture detector.

Results showed a clear difference between TCBT and PCB-5 Cl: in fish, bioaccumulation of TCBT was relatively slight and the 50% depuration time was approximately 26 days; in rat liver and fats, TCBT was also only weakly accumulated and rapidly eliminated. This contrasted sharply with the findings for PCB-5 Cl, viz: high accumulation potential and slow elimination.

Observed rates of bioaccumulation and elimination of TCBT and PCB-5 Cl by the rat were in good agreement with the toxicological findings for the same species.     

Bioaccumulation of decamethylcyclopentasiloxane in perch in Swedish lakes

Decamethylcyclopentasiloxane (D5), a high production volume chemical used in personal care products, enters the environment both via air and sewage treatment plant (STP) recipients. It has been found in fish, and there is concern that it may be a bioaccumulative substance. In this work D5 was analyzed in perch from six Swedish lakes that did not receive STP effluent, and in perch and sediment from six lakes that received STP effluent. In the lakes receiving the STP effluent, the D5 concentrations in sediment varied over three orders of magnitude and were correlated with the number of persons connected to the STP normalized to the surface area of the receiving body. In the lakes not receiving effluent, the D5 levels in perch were all below the LOQ, while D5 was above the LOQ in almost all perch from lakes that received effluent. The D5 concentrations in perch and sediment from the lakes receiving STP effluent were correlated. This shows that STP effluent is a much more important source of D5 to aquatic ecosystems than atmospheric deposition, and that the risk of adverse effects of D5 on aquatic life will be greatest in small recipients receiving large amounts of STP effluent. The bioaccumulation of D5 was compared to that of PCB 180 on the basis of multimedia bioaccumulation factors (mmBAFs), which describe the fraction of the contaminant present in the whole aquatic environment (i.e. water and surface sediment) that is transferred to the fish. In four of the six lakes the mmBAF of D5 was >0.3 of the mmBAF of PCB 180. Given that PCB 180 is a known highly bioaccumulative chemical, this indicates that the bioaccumulation of D5 in perch is considerable.     

Environmental factors and spatiotemporal distribution characteristics of the global outbreaks of the highly pathogenic avian influenza H5N1

The spread of highly pathogenic avian influenza H5N1 has posed a major threat to global public health. Understanding the spatiotemporal outbreak characteristics and environmental factors of H5N1 outbreaks is of great significance for the establishment of effective prevention and control systems. The time and location of H5N1 outbreaks in poultry and wild birds officially confirmed by the World Organization for Animal Health from 2005 to 2019 were collected. Spatial autocorrelation analysis and multidistance spatial agglomeration analysis methods were used to analyze the global outbreak sites of H5N1. Combined with remote sensing data, the correlation between H5N1 outbreaks and environmental factors was analyzed using binary logistic regression methods. We analyzed the correlation between the H5N1 outbreak and environmental factors and finally made a risk prediction for the global H5N1 outbreaks. The results show that the peak of the H5N1 outbreaks occurs in winter and spring. H5N1 outbreaks exhibit aggregation, and a weak aggregation phenomenon is noted on the scale close to 5000 km. Water distance, road distance, railway distance, wind speed, leaf area index (LAI), and specific humidity were protective factors for the outbreak of H5N1, and the odds ratio (OR) were 0.985, 0.989, 0.995, 0.717, 0.832, and 0.935, respectively. Temperature was a risk factor with an OR of 1.073. The significance of these ORs was greater than 95%. The global risk prediction map was obtained. Given that the novel coronavirus (COVID-19) is spreading globally, the methods and results of this study can provide a reference for studying the spread of COVID-19.

     

Simulated use and wash-off release of decamethylcyclopentasiloxane used in anti-perspirants

The cyclic volatile methylsiloxane, decamethylcyclopentasiloxane (D₅) is used in a large variety of personal care products. Based on the physical–chemical properties of D₅, it is likely that losses due to volatilisation may strongly influence the levels entering the aquatic environment. The aim of this study was to quantify the amount of D₅ in waste wash water, after typical application and use in a range of deodorant and anti-perspirant (AP) products. Results implied significant losses after a 24 h period (>99.9%), and suggest that the use of D₅ in leave-on products, such as deodorants/AP is not likely to contribute a significant down-the-drain emission source. An illustrative example is presented, based on data reporting the use of D₅ in a range of personal care products (both wash-off and leave-on), which suggests that the contribution of D₅ used in wash-off products to the aquatic environment may be considerably more significant. Limitations associated with our understanding of the actual D₅ inclusion levels in the products, the market share of the products containing D₅, and the variability of consumer habits, are identified as data gaps that need to be addressed in order to better refine down-the-drain emission estimates.     

Synthesis and application of Cu-BTC@ZSM-5 composites as effective adsorbents for removal of toluene gas under moist ambience: kinetics,thermodynamics, and mechanism studies

Metal organic frameworks (MOFs) are excellent adsorbents that provide abundant specific surface area, adjustable pore structure, and rich active sites. The purpose of this study was to prepare composites with hydrophobic and high microporous specific surface area and to adsorb toluene gas in moist ambience. An ethanol activation-assisted hydrothermal method was proposed to synthesize copper-benzene-1,3,5-tricarboxylic acid (Cu-BTC) metal-organic framework, Cu-BTC, and ZSM-5 molecular sieve composites (Cu-BTC@ZSM-5). The dynamic adsorption process of toluene on different adsorbents was investigated, and the results showed that the toluene adsorption capacity of Cu-BTC@ZSM-5 (158.6 mg/g) was 2.53 times higher than Cu-BTC (62.7 mg/g), when the ZSM-5 content is 5% and the humidity is 30%RH. Compared with other factors, the humidity inhibited the adsorption of toluene on Cu-BTC@ZSM-5. Langmuir model and the pseudo-second kinetics model can better describe the adsorption behavior of Cu-BTC@ZSM-5. The thermodynamic results showed the adsorption process was a spontaneous exothermic process at low temperature and mainly physical adsorption. The relative regenerability can still up to 80.4% after six cycles. The adsorption mechanisms of Cu-BTC@ZSM-5 were pore-filling adsorption, π-π interaction, cation-π bonding, and hydrophobic interactions. This study will help to design a systematic route to evaluate the adsorption performance of Cu-BTC@ZSM-5 for toluene.

     

International cross-validation of a BOD5 surrogate

BOD5 dates back to 1912 when the Royal Commission decided to use the mean residence time of water in the rivers of England, 5 days, as a standard to measure the biochemical oxygen demand. Initially designed to protect the quality of river waters from extensive sewage discharge, the use of BOD5 has been quickly extended to waste water treatment plants (WWTPs) to monitor their efficiency on a daily basis. The measurement has been automatized but remains a tedious, time- and resource-consuming analysis. We have cross-validated a surrogate BOD5 method on two sites in France and in the USA with a total of 109 samples. This method uses a fluorescent redox indicator on a 96-well microplate to measure microbial catabolic activity for a large number of samples simultaneously. Three statistical tests were used to compare surrogate and reference methods and showed robust equivalence.     

Effects of copper on spore germination, growth and ultrastructure of Polypodium cambricum L. gametophytes

The effects of different concentrations (10(-5), 5x10(-5) and 10(-4)M) of copper bromide on spore germination, growth and ultrastructure were investigated in Polypodium cambricum L. gametophytes. The inhibitory effect of Cu was observed in spores cultured on medium supplemented with 10(-4)M CuBr(2): germination occurred about 40 days after sowing and was only 25%. Concentrations of 5x10(-5) and 10(-4)M CuBr(2) induced changes in gametophyte development, possibly by re-orientation of growth. Gametophytes treated with 10(-5) and 5x10(-5)M CuBr(2) took up and accumulated a large amount of copper and ultrastructural observations showed that cytoplasmic damage was limited to twisted swollen thylakoids. The ultrastructure of gametophytes treated with 10(-4)M CuBr(2) showed absence of a vacuolar compartment. The present observations suggest that P. cambricum gametophytes could be a suitable material for studying physiological and molecular alterations induced by excess copper.     

Ca5（AsO4）3OH的溶解度与稳定性研究

通过在不同pH值,温度等条件下Ca5（AsO4）3OH的溶解,确定其稳定存在的pH值范围,得出它的溶度积和生成的自由能（ΔG0f）。结果表明,Ca5（AsO4）3OH在水中的溶解度和稳定范围与pH和温度有关,在酸性条件下（初始pH=2）它的溶解度较大,而且在水中的溶解度随着温度的升高而降低。利用PHREEQC程序计算确定Ca5（AsO4）3OH的溶度积为10-40.86,生成自由能ΔG0f为-5 063.53 kJ/mol。利用JADE5软件计算得到其晶格参数a=b=9.696,c=6.967和晶胞体积为567.304 3。     

Applying Hexagonal Nanostructured Zeolite Particles for Acetone Removal

Abstract

This study examines the performance of a new adsorbent, hexagonal nanostructured zeolite particles (HNZP) for acetone adsorption and compares the results with that of commercial mobil synthetic zeolite-5 (ZSM-5) type zeolite. The HNZP is a pure siliceous adsorbent with different values of pore diameter and surface area being adjustable by the manufacturing condition. The results indicate that a slight increase in the average pore diameter (d) of HNZP from 2 to 2.5 nm leads to an increase in the acetone adsorption capacity, although its surface area is decreased, in which case (d = 2.5 nm) the adsorption capacity of fresh HNZP is better than that of ZSM-5 zeolite. Even for the fresh HNZP (d = 2 nm) of which the adsorption capacity is less than that of the ZSM-5 zeolite at relative humidity (RH) of 0%, its adsorption capacity is not deteriorated after repeated regeneration, but the adsorption capacity of regenerated ZSM-5 zeolite decays markedly. Thus, after only one regeneration, the adsorption capacity of HNZP (d = 2 nm) becomes better than that of the ZSM-5 zeolite. The decrease in the adsorption capacity of regenerated ZSM-5 zeolite might be because of its aluminum content that catalyzes the acetone into coke and, thus, blocks the adsorption sites. Furthermore, result on the moisture effect shows that because the pure siliceous HNZP was more hydrophobic than the ZSM-5 zeolite, the acetone adsorption efficiency of fresh HNZP (d = 2 nm) is better than that of ZSM-5 zeolite at RH = 50%.     

Applying hexagonal nanostructured zeolite particles for acetone removal

This study examines the performance of a new adsorbent, hexagonal nanostructured zeolite particles (HNZP) for acetone adsorption and compares the results with that of commercial mobil synthetic zeolite-5 (ZSM-5) type zeolite. The HNZP is a pure siliceous adsorbent with different values of pore diameter and surface area being adjustable by the manufacturing condition. The results indicate that a slight increase in the average pore diameter (d) of HNZP from 2 to 2.5 nm leads to an increase in the acetone adsorption capacity, although its surface area is decreased, in which case (d = 2.5 nm) the adsorption capacity of fresh HNZP is better than that of ZSM-5 zeolite. Even for the fresh HNZP (d = 2 nm) of which the adsorption capacity is less than that of the ZSM-5 zeolite at relative humidity (RH) of 0%, its adsorption capacity is not deteriorated after repeated regeneration, but the adsorption capacity of regenerated ZSM-5 zeolite decays markedly. Thus, after only one regeneration, the adsorption capacity of HNZP (d = 2 nm) becomes better than that of the ZSM-5 zeolite. The decrease in the adsorption capacity of regenerated ZSM-5 zeolite might be because of its aluminum content that catalyzes the acetone into coke and, thus, blocks the adsorption sites. Furthermore, result on the moisture effect shows that because the pure siliceous HNZP was more hydrophobic than the ZSM-5 zeolite, the acetone adsorption efficiency of fresh HNZP (d = 2 nm) is better than that of ZSM-5 zeolite at RH = 50%.