Fermentative hydrogen evolution by Enterobacter aerogenes strain E.82005

Fermentative hydrogen evolution by Enterobacter aerogenes strain E.82005 was studied with cultivations performed under both controlled and uncontrolled pH. Results show that the transient rate of hydrogen evolution on the glucose and peptone liquid culture exceeded 420 ml (g-dry cell h)⁻¹ under uncontrolled cultivation and that about 1 mole of glucose was required to generate 1 mole of hydrogen by the bacterial fermentation. In addition, the pH of the culture was found to have important influences on the hydrogen evolving activities of the st. E.82005. The activity reached a maximum (520 ml (1-culture-h)⁻¹) at pH 6.0 asnd 40.5°C. However, the most vigorous growth of cell was found to occur at pH 7.0.     

箭叶淫羊藿提取物活性成分、抗氧化及酶抑制活性分析

目的:研究评价箭叶淫羊藿提取物的活性成分、含量及体外生物活性。方法:通过分光光度法测定箭叶淫羊藿提取物总多酚、总黄酮、总多糖及原花青素含量;利用高效液相色谱（HPLC）法测定提取物5种黄酮类化合物含量;通过清除DPPH、OH、ABTS+自由基法评价了箭叶淫羊藿提取物的抗氧化活性,并测定了对胰脂肪酶、酪氨酸酶、乙酰胆碱酯酶和丁酰胆碱酯酶的抑制作用。结果:箭叶淫羊藿提取物中总多酚、总黄酮、总多糖及原花青素含量分别为105.60±0.92、70.09±0.75、18.45±1.27、8.79±0.13 mg/g;HPLC测定5种黄酮类成分中淫羊藿苷含量最高、朝藿定C次之,分别为266.16±4.22和43.35±0.67 mg/g,宝藿苷I含量最少,为2.54±0.07 mg/g;箭叶淫羊藿提取物对DPPH·、·OH、ABTS+·半数清除浓度（IC₅₀）分别为4.43±0.40、2.83±0.09、2.04±0.08 mg/mL,清除能力呈一定的浓度依赖性;同时,箭叶淫羊藿提取物对脂肪酶、酪氨酸酶、乙酰/丁酰胆碱酯酶的半数抑制浓度（IC₅₀）分别为5.97±0.04、2.27±0.23、9.27±0.07、7.41±0.26 mg/mL。结论:箭叶淫羊藿提取物活性物质丰富,对DPPH、OH、ABTS+自由基具有较好的清除作用,对胰脂肪酶、酪氨酸酶、乙酰胆碱酯酶和丁酰胆碱酯酶有一定的抑制作用。     

Estimation of non-uniquely identifiable parameters via exhaustive modeling and membership set theory

A new methodology for estimating parameters that are not structurally globally identifiable is presented. The set of all the models which have exactly the same input–output behavior is first generated. The influence of the measurement noise and structural error is then taken into account by assuming that upper and lower bounds of the acceptable output error are available. The set of all the models compatible with this hypothesis is characterized, and ranges for the possible values of the estimated parameters are provided. An example is treated involving two real–life model structures used to describe the behavior of an isotopic tracer in a reactor producing methane from carbon monoxide and hydrogen.     

Enterovirus removal from sewage: The effectiveness of four different treatment plants

Human enterovirus removal from effluents at four different sewage treatment plants was tested, an oxidation pond system, two utilising trickling filtration and the fourth incorporating sedimentation and chlorination. Virus numbers were not significantly reduced by any of the treatment plants.No correlation was found between virus numbers and faecal coliforms, suspended solids, pH or conductivity.Seasonal fluctuations in virus numbers indicated that more enteroviruses were present in the summer months than in the winter.     

Life on a seamount: Lake charr at Stannard Rock,Lake Superior, 2011–2015

Lake Superior has four extant lake charr ecotypes including the ubiquitous lean (shallow-water form), the deep-water siscowet, and the less common, mid-depth redfin and humper forms. Stannard Rock is a distant seamount in Michigan waters that is a coveted recreational lean lake charr fishing destination. Lake charr at Stannard Rock were surveyed during 2011–2015 using gill nets set in waters <80 and ≥80 m to assess population status. All four ecotypes were found at Stannard Rock with leans being most abundant at depths <80 m and humpers and siscowets most abundant in waters ≥80 m. Few redfins were found. Total annual mortality was estimated to be 24% for leans, 18% for humpers, and 15% for siscowets. Population age and size structure of lake charr were broad with many fish older than 20 years and >700 mm. Asymptotic length was 891 mm for leans, 459 mm for humpers, and 938 mm for siscowets. Female length at 50% maturity was 547 mm for leans, 382 mm for humpers, and 453 mm for siscowets. Recreational fishery total harvest of leans peaked at 5,000 fish per year during 2011–2015. Overall, lake charr populations at Stannard Rock were healthy. Caution must be exercised because harvest levels were modest at Stannard Rock, which has a small area relative to nearshore lake charr habitat. These findings support the concept put forth by progressive recreational fishers that have advocated assigning Stannard Rock as a heritage fishery area with restrictive regulations to maintain its sustainability.     

In situ construction of oxygen deficient MoO3-x nanosheets/porous graphitic carbon nitride for enhanced photothermal-photocatalytic hydrogen evolution

In this work, the photocatalysts containing oxygen-deficient molybdenum oxide and macroscopic three-dimensional porous graphitic carbon nitride phase composite (MoO_3-x/PCN) were prepared by in situ self-assembly method. The crystal phase and structure were characterized by XRD, XPS, FT-IR, SEM, and TEM measurements. Hydrogen production results showed that introducing of MoO_3-x resulted in a higher hydrogen production rate of MoO_3-x/PCN composite catalyst than that of PCN. Among them, the highest hydrogen production rate of 2336.15 μmol g⁻¹ h⁻¹ was achieved for MoO_3-x-10/PCN, which was 2.23 times higher than PCN (1048.00 μmol g⁻¹ h⁻¹). When the reaction system temperature was 100 °C, the photothermal hydrogen production rate of MoO_3-x-10/PCN was 8902.00 μmol g⁻¹ h⁻¹, which was 3.81 times higher than that at room temperature. PL spectra, UV–vis spectra and photoelectrochemical measurements showed that the localized surface plasmon resonance (LSPR) effect of MoO_3-x effectively enhanced the photo response range and increased the temperature of the reaction system. ESR measurements showed that he composites should follow the Z-scheme charge transfer mechanism, the electrons in the CB of MoO_3-x further migrate to the VB of PCN, which hinders the charge complexation in MoO_3-x and PCN, improving the hydrogen production activity. This study provides a new idea for constructing a plasma-based photothermal synergistic catalytic hydrogen production strategy.     

The effect of chemical composition and morphology on the drug delivery properties of hydroxyapatite-based biomaterials

In the case of orthopedic and dental interventions, local antibiotic therapy reduces significantly the risk associated with the intervention. The aim of this study was the preparation and characterization of pure hydroxyapatite (HA), Si- and Mg-doped HA, which ensures the sustained release of doxycycline, and the investigation of the parameters, which were crucial for the drug release. The carriers were synthesized using the precipitation method. In order to achieve different morphologies, traditional drying and spray drying methods were used: Si-doped HA was prepared using two different sources of Si, Na₂SiO₃ and Ludox AS-40, while (Mg(NO₃)₂)*6H₂O was used for substitution with Mg. The carriers were characterized by XRD, SEM, EDX and TG/DTA methods, and the ion incorporation was also confirmed by lattice parameters calculations. Doxy was bound on the carriers by physical adsorption, the adsorption capacity increased proportionally by increasing the concentration of the initial Doxy solutions (10, 15, 20, 25 g/L). The investigated systems showed different releases with the change of the dissolution medium (in the case of HA microspheres, the release in PBS was twice as high as in SBF), chemical composition and morphology of the carriers. The retard effect of the carriers was improved by the spherical morphology, and the reduced release by ion substitution in both SBF and PBS increased as follows: HA < HASi1<HAMg < HASi2. The release mechanism of Doxy was discussed through five different release kinetics models.