Studies on the antioxidant activity and phenolic compounds of enzyme-assisted water extracts from Du-zhong (Eucommia ulmoides Oliv.) leaves

Enzyme-assisted water extracts (EWEDL) and ethanol extracts of Du-zhong leaves (EEDL) were evaluated for their antioxidant activities using the DPPH radical-scavenging assay, Fe²⁺-chelating assay, and inhibition ability of the linoleic acid peroxidation assay. In general, the antioxidant activity of Du-zhong leaf extracts increased with increasing concentration. Based on the two extracting methods with different antioxidative reactions, it was shown that the enzyme-assisted water extracting method was more effective for antioxidant extraction from Du-zhong leaves. By HPLC-MS analysis, the main phenolic compounds (geniposidic acid, epicatechin, and chlorogenic acid) identified in EWEDL and EEDL were similar. EWEDL and EEDL had total phenolic contents of 13.84?±?0.11 and 14.72?±?0.14?mg chlorogenic acid equivalents (CAE) in each gram of extract, respectively. However, there was no positive correlation between total phenolic content and antioxidant activities of EWEDL and EEDL measured by the three different assays.     

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Archival formalin-fixed, paraffin-embedded (FFPE) tissue and their associated diagnostic records represent an invaluable source of retrospective proteomic information on diseases for which the clinical outcome and response to treatment are known. However, analysis of archival FFPE tissues by high-throughput proteomic methods has been hindered by the adverse effects of formaldehyde fixation and subsequent tissue histology. This review examines recent methodological advances for extracting proteins from FFPE tissue suitable for proteomic analysis. These methods, based largely upon heat-induced antigen retrieval techniques borrowed from immunohistochemistry, allow at least a qualitative analysis of the proteome of FFPE archival tissues. The authors also discuss recent advances in the proteomic analysis of FFPE tissue; including liquid-chromatography tandem mass spectrometry, reverse phase protein microarrays and imaging mass spectrometry.     

ARSENIC CHEMISTRY AND REMEDIATION IN HAWAIIAN SOILS

Past use of arsenical pesticides has resulted in elevated levels of arsenic (As) in some Hawaiian soils. Total As concentrations of 20–100 mg/kg are not uncommon, and can exceed 900 mg/kg in some lands formerly planted with sugarcane. With high contents of amorphous aluminosilicates and iron oxides in many Hawaii's volcanic ash-derived Andisols, a high proportion (25–30%) of soil As was associated with either these mineral phases or with organic matter. Less than 1% of the total As was water soluble or exchangeable. Furthermore, the soils can sorb As strongly: the addition of 1000 mg/kg as As (+5) resulted in only between 0.03 and 0.30 mg/L As in soil solution. In contrast, soils having more crystalline minerals (e.g., Oxisols) sorb less As and thus often contain less As. Phosphate fertilization increases As bioaccessibility, whereas the addition of Fe(OH)₃ decreases it. Brake fern (Pteris vittata L.) can be used to remove some soil As. Concentrations of As in fronds varied on average from 60 mg/kg when grown on a low-As Oxisol to 350 mg/kg when grown on a high-As Andisol. Ratios of leaf As to CaCl₂-extractable soil As were 12 and 222 for the Oxisol and Andisol, respectively.     

Continuous countercurrent salting-out extraction of 1,3-propanediol from fermentation broth in a packed column

The possibility of continuous extraction of 1,3-propanediol in a experimental packed column was investigated using a salting-out extraction system of dipotassium phosphate/ethanol. Mass transfer of 1,3-propanediol takes place from the dispersed phase (salt-rich solution) to the continuous phase (ethanol). The influences of flow rate of dispersed phase and size of packing material on partition coefficient and recovery of 1,3-propanediol were investigated and the results were compared with those obtained in spray column and test tube. Furthermore, the influences of various system compositions on hold up of dispersed phase, mass transfer coefficient, and system stability were also studied in the column packed by stainless steel Dixon 3 × 3 mm. It was found that the packed column showed a good extraction efficiency and stability. Besides, 1,3-propanediol recovery of 90.30% was obtained during a 11 h continuous operation when the real fermentation broth was used. At the same time, 94.4% of phosphate could be recovered when 0.2 volume of anhydrous ethanol was added into the raffinate phase at pH 4.0.     

Blood Perfusion in a Murine Fibrosarcoma Tumor Model After Direct Current Electrotherapy a Study with 86Rb Extraction Technique

Electrotherapy with low-level direct current (DC) can induce antitu-mor effects in various tumor models. Applied in combination with certain anticancer drugs, it can significantly increase their effectiveness. It has been suggested that the demonstrated effects of electrotherapy arise from its modification of tumor blood flow. The effect of such treatment on blood perfusion of solid subcutaneous Sa-1 fibrosarcoma tumors in A/J mice was investigated with a ⁸⁶rubidium extraction technique. Following electrotherapy, the relative tissue perfusion of tumors was decreased by more than 50%. Three days after treatment, partial reperfusion of tumors occurred. The dynamics of the perfusion changes induced by electrotherapy are in agreement with tumor growth dynamics following this procedure. The effect of electrotherapy on the blood supply of tumors may be the major mechanism of antitumor action in our model. Electrotherapy could be useful as an adjuvant local procedure to other treatment modalities that require a hypoxic environment for their effectiveness.     

High throughput preparation of fly genomic DNA in 96-well format using a paint-shaker

Sample homogenization is an essential step for genomic DNA extraction, with multiple downstream applications in Molecular Biology. Genotyping hundreds or thousands of samples requires an automation of this homogenization step, and high throughput homogenizer equipment currently costs 7000 euros or more. We present an apparatus for homogenization of individual Drosophila adult flies in 96-well micro-titer dishes, which was built from a small portable paint-shaker (F5 portable paint-shaker, Ushake). Single flies are disrupted in each well that contains extraction buffer and a 4-mm metal ball. Our apparatus can hold up to five 96-well micro-titer plates. Construction of the homogenizer apparatus takes about 3–4 days, and all equipment can be obtained from a home improvement store. The total material cost is approximately 700 euros including the paint-shaker. We tested the performance of our apparatus using the ZR-96 Quick-gDNA? kit (Zymo Research) homogenization buffer and achieved nearly complete tissue homogenization after 15 minutes of shaking. PCR tests did not detect any cross contamination between samples of neighboring wells. We obtained on average 138 ng of genomic DNA per fly, and DNA quality was adequate for standard PCR applications. In principle, our tissue homogenizer can be used for isolation of DNA suitable for library production and high throughput genotyping by Multiplexed Shotgun Genotyping (MSG), as well as RNA isolation from single flies. The sample adapter can also hold and shake other items, such as centrifuge tubes (15–50 mL) or small bottles.     

Identification and Quantitation of New Glutamic Acid Derivatives in Soy Sauce by UPLC/MS/MS

Glutamic acid is an abundant amino acid that lends a characteristic umami taste to foods. In fermented foods, glutamic acid can be found as a free amino acid formed by proteolysis or as a non‐proteolytic derivative formed by microorganisms. The aim of the present study was to identify different structures of glutamic acid derivatives in a typical fermented protein‐based food product, soy sauce. An acidic fraction was prepared with anion‐exchange solid‐phase extraction (SPE) and analyzed by UPLC/MS/MS and UPLC/TOF‐MS. α‐Glutamyl, γ‐glutamyl, and pyroglutamyl dipeptides, as well as lactoyl amino acids, were identified in the acidic fraction of soy sauce. They were chemically synthesized for confirmation of their occurrence and quantified in the selected reaction monitoring (SRM) mode. Pyroglutamyl dipeptides accounted for 770 mg/kg of soy sauce, followed by lactoyl amino acids (135 mg/kg) and γ‐glutamyl dipeptides (70 mg/kg). In addition, N‐succinoylglutamic acid was identified for the first time in food as a minor compound in soy sauce (5 mg/kg).     

牡丹种皮黄酮提取及对ABTS自由基清除作用

以丹凤牡丹（Paeonia ostii）种皮为原料,采用正交实验法对影响牡丹种皮总黄酮匀浆提取含量的主要因素进行研究分析,考察了乙醇浓度、料液比、匀浆时间、匀浆次数4个因素的影响,筛选出最佳工艺条件,乙醇浓度80%,液料比20∶1,匀浆时间4 min,匀浆次数2次。并在最佳工艺条件下进行验证实验,得牡丹种皮黄酮提取物含量为52.19 mg·g^-1。测定了牡丹种皮黄酮对2,2-联氨-双（3-乙基苯并噻唑啉-6-磺酸）二胺盐(ABTS)自由基的清除效果,结果表明牡丹种皮黄酮的抗氧化能力强于2,6-二叔丁基-4-甲基苯酚(BHT),为牡丹种皮变废为宝提供了科学依据。     

Sequential adaptive variables and subject selection for GEE methods

Modeling correlated or highly stratified multiple-response data is a common data analysis task in many applications, such as those in large epidemiological studies or multisite cohort studies. The generalized estimating equations method is a popular statistical method used to analyze these kinds of data, because it can manage many types of unmeasured dependence among outcomes. Collecting large amounts of highly stratified or correlated response data is time-consuming; thus, the use of a more aggressive sampling strategy that can accelerate this process—such as the active-learning methods found in the machine-learning literature—will always be beneficial. In this study, we integrate adaptive sampling and variable selection features into a sequential procedure for modeling correlated response data. Besides reporting the statistical properties of the proposed procedure, we also use both synthesized and real data sets to demonstrate the usefulness of our method.     

Human disturbance and the activity patterns and temporal overlap of tapirs and jaguars in reserves of NW Belize

Human disturbance from tourism and other non-consumptive activities in protected areas may be stressful to wildlife. Animals may move away in space or time to avoid human interaction. For species of particular conservation concern, such as Baird's tapirs (Tapirus bairdii) and jaguars (Panthera onca), a better understanding of how they respond to different levels and types of disturbance is needed in order to manage human visitation to parks in ways that minimize negative outcomes for wildlife. We describe the overlap in activity patterns of tapirs, jaguars, and humans at logged and unlogged sites and at places with low versus high human visitation using camera survey data from protected areas of NW Belize, 2013–2016. Tapirs were nocturnal in all study sites, with > 80% of all tapir detections occurring between 1900 hr and 0500 hr. Their activity patterns were not different in unlogged versus logged sites and did not change with increased human traffic. Jaguars were cathemeral across sites but had more nocturnal activity at the site with the most human impact. Activity pattern overlap between tapirs and jaguars did not differ significantly between logged and unlogged sites, nor between areas with low and high human activity. Human traffic increased from 2013 to 2016 at most of the study locations. In conclusion, this camera trap dataset suggests that non-consumptive human disturbance does not alter the activity patterns of tapirs and jaguars in protected areas lacking hunting pressure.