不同播种期阳春砂种子的发芽实验研究

[目的] 探索阳春砂种子发芽的动态变化规律,明确砂仁种子的适宜播种期及储存期.[方法] 采用室外盆播方式,以5 d为1个间隔进行16期播种,观察出苗状况,记录实验数据并计算发芽率及发芽势.[结果] 湿沙储藏的春砂仁种子从8月26日至10月20日经分期播种,其发芽率及发芽势从低至高呈曲线上升趋势,9月前播种者发芽势不明显,10月25日播种则发芽率明显下降,且发芽势不明显;经湿沙储藏的春砂仁种子适用期或储存期为2个月;种子越成熟发芽力越高.[结论] 湿沙储藏可延长砂仁种子的适用期限;8月下旬至10月中下旬之间砂仁适期迟播比早播的发芽率及发芽势高,但结合生产实践考虑,9月20目前是湿沙藏砂仁种子的适宜播种期.     

Repurposing fallen leaves to bio-based reaction medium for hydration,hydroxylation, carbon-carbon and carbon-nitrogen bond formation reactions

A green reaction medium has been developed from the Water Extract of Teak leaf (Tectona grandis) ash (WET). The alkaline nature of the WET was successfully applied towards hydration of nitriles, conversion of arylboronic acids to phenols with 30% aqueous H₂O₂, Knoevenagel condensation for benzylidenemalononitrile derivatives formation and Chan-Lam reaction of arylboronic acids with imidazole derivatives. In current protocols dual role of WET as reaction medium as well as base has been explored. A wide range of substrates with varying electronic natures is compatible under these WET mediated reaction conditions with excellent yields.     

Determination of acute and early life stage toxicity of fat-plant effluent using zebrafish (Danio rerio)

The present study examines the effects of an effluent from a fat plant (FP) on zebrafish (Danio rerio) embryos and larvae using the whole effluent toxicity testing methods (WET). The method is based on acute toxicity using 96-h larval mortality and chronic toxicity using endpoints such as the time to hatch, hatching success, deformity, growth rate, swim-up failure, accumulative mortality, and sex ratio. On the basis of larval mortality the 96-h LC(50) (the concentration was lethal to 50% of newly hatching zebrafish larvae) was 68.9%. In chronic toxicity test, newly fertilized embryos (<5-h old) were exposed to 1, 6, 12, 25, 50% effluent concentrations in a 24-h static renewal system at (27 +/- 0.5) degrees C until 15-day posthatch. The results showed that all chronic endpoints were significantly different from the control at 50% dilution. Embryos began to show lesions on third day at higher concentrations (12, 25, 50% FP effluent concentrations). Treatment group of 25% dilution showed delayed time to hatch. Morphological abnormalities were observed in newly hatched larvae at 25 and 50% FP effluent concentrations. At 25% dilution, sex ratio of larvae was alternated and there was feminization phenomenon. On the basis of the study, the FP effluent tested here may cause increasing embryotoxicity in the zebrafish embryos. We conclude that the test using zebrafish is feasible to evaluate both acute and chronic toxicities of industrial effluents.     

Comparison of DRY and WET vaginal swabs with cervical specimens in Roche Cobas 4800 HPV and Abbott RealTime High Risk HPV tests

BackgroundSelf-collected vaginal swab samples have been proposed as an alternative specimen collection method for human papillomavirus (HPV) DNA detection.ObjectivesTwo vaginal swabs (a cone-shaped flocked swab (DRY) and a L-shape FLOQSwab with 2 mL eNAT transport medium (WET)) were compared to standard cervical samples for HPV DNA testing. Additionally, they were also compared by using Roche Cobas 4800 HPV (Roche_HPV) and Abbott Real-time High Risk HPV (Abbott_HPV) tests.Study designNinety-six women were prospectively enrolled from the National Cancer Center in Korea between June and August 2015. WET and DRY vaginal swabs and cervical specimens were collected. Roche_HPV and Abbott_HPV tests were performed. The Roche_HPV test on cervical specimens was used as reference.ResultsThe observed agreements (kappa) of Roche_HPV and Abbott_HPV between WET and DRY swabs were 89.6% (0.790, 95% confidence interval (95% CI): 0.667–0.913) and 91.7% (0.833, 95%CI: 0.723–0.943), respectively. No statistical difference was observed between WET and DRY swabs (p > 0.05 for all comparisons). For HPV16/18, the sensitivity/specificity of Roche_HPV on the DRY and WET samples presented 93.8%/96.3% and 87.5%/97.5%, respectively. For other High Risk HPV (hrHPV), the sensitivity/specificity of Roche_HPV on the DRY and WET swabs presented 91.9%/91.5% and 97.3%/98.3, respectively. The sensitivity/specificity of the Abbott_HPV on the DRY and WET swabs were 93.8%/98.8%, 87.5%/98.8% for HPV16/18, and 91.9%/93.2%, 100.0%/93.2% for other hrHPV, respectively.ConclusionsHPV tests performed similarly when using vaginal DRY and WET swab samples. Using DRY and WET swabs to collect vaginal specimens could be an alternative to collecting cervical samples for HPV DNA testing.     

Imaging and Characterization of Engineered Nanoparticles in Sunscreens by Electron Microscopy,Under Wet and Dry Conditions

Abstract

There is increasing concern over the risks of nanoparticles to humans and the environment, but little is known about the properties of the nanoparticulate mineral filters, such as titanium dioxide and zinc oxide, in sunscreens. There is an urgent need to develop methods for characterizing nanoparticles in (NPs) such products to provide data for human and environmental risk assessments. This study explored three methods (transmission electron microscopy [TEM], conventional scanning electron microscopy [SEM], and wet-scanning electron microscopy [WetSEM]) for characterizing NPs in sunscreens. Our results showed that these products contained titanium dioxide and zinc oxide particles in the nanometer range; thus, it is likely that consumers and the environment are exposed to engineered NPs through the use of these products. Further, we found that the combination of all three microscopy methods provided the most comprehensive information on size-related properties, which are crucial parameters for risk assessment of NPs in wet matrices.     

International Trends in Bioassay Use for Effluent Management

The use of effluent bioassays in various international jurisdictions is reviewed, resulting in an analysis of themes and trends in: regulatory use, different uses of bioassays in meeting protection goals, different types of bioassays, bioassay test variability, statistical design, use of effluent bioassays to predict receiving environment effects, and uptake of effluent bioassay testing by developing countries. Current effluent bioassay use by jurisdictions in North America, the European Union, and Asia/Pacific is described. The historical trend for many jurisdictions has been to start with chemical hazard-based systems, then add effluent bioassays (first lethal, then sublethal measures) and then use receiving environment evaluations to predict or measure impacts. For jurisdictions adopting effluent bioassays over the past decade, policies about the use of in vivo vertebrate tests appear to be influencing the types of bioassays that are used and there is also a trend towards micro-scale tests. In countries where regulations relating to effluent management do not require effluent bioassays, uptake of bioassays is relatively slow. Good practice for effluent bioassay applications can only be defined with regard to the regulatory regime, as differences between jurisdictions (e.g., hazard-based versus risk-based regimes, policies on in vivo vertebrate testing) will result in different choices.     

Properties of Antibacterial Polypropylene/Nanometal Composite Fibers

Melt spinning of polypropylene fibers containing silver and zinc nanoparticles was investigated. The nanometals were generally uniformly dispersed in polypropylene, but aggregation of these materials was observed on fiber surface and in fiber cross-sections. The mechanical properties of the resulted composite fibers with low concentration of nanometal were comparable to those for the control PP yarns. Extruded composite fibers that contained 0.72% silver and 0.60% zinc nanoparticles had outstanding antibacterial efficacy as documented by the percentage count reduction growth of Escherichia coli and Staphylococcus aureus. Fibers containing silver particles had improved antistatic properties.     

Preparation and Characterization of TAM-Loaded HPMC/PAN Composite Fibers for Improving Drug-Release Profiles

The present paper reports the preparation and characterization of composite hydroxypropyl methylcellulose/polyacrylonitrile (HPMC/PAN)-medicated fibers via a wet spinning technique. Tamoxifen (TAM) was selected as a model drug. Numerous analyses were conducted to characterize the mechanical, structure and morphology properties of the composite fibers. The drug content and in vitro dissolution behavior were also investigated. SEM images showed that the TAM-loaded HPMC/PAN composite fibers had a finger-like outer skin and a porous structure. FT-IR spectra demonstrated that there was a good compatibility between polymer and drug. Results from X-ray diffraction and DSC suggested that most of the incorporated TAM was evenly distributed in the fiber matrix in an amorphous state, except for a minority that aggregated on the surface of fibers. The drug content in the fibers was lower than that in the spinning solution and about 10% of TAM was lost during spinning process. In vitro dissolution results indicated that, compared to TAM–PAN fibers, HPMC/PAN composite systems had weaker initial burst release effects and more drug-loading. The combination of hydrophilic polymer HPMC with PAN could improve the performance of polymer matrix composite fibers in regulating the drug-release profiles.     

Assessing the Relationship Between Laboratory Whole Effluent Toxicity Test Data and In-Stream Biological Communities

The ability of whole effluent toxicity (WET) tests to predict in-stream effects to periphyton, benthic macroinvertebrates, and fish in a habitat-impaired stream was assessed. Habitat assessment data were useful in interpreting in-stream conditions for periphyton and benthic macroinvertebrates. Various periphyton and macroinvertebrate metrics identified siltation effects as opposed to water quality effects in-stream. Pathogen effects noted in fathead minnow WET tests were not reflected in the fish community. Overall, in-stream biological conditions confirmed the absence of water quality-related effects as predicted by WET tests.     

Comparative Whole Effluent Toxicity Assessment of Wastewater Treatment Plant Effluents using Daphnia magna

An approach to compare the toxicities employing the whole effluent toxicity (WET) test, using Daphnia magna and chemical analysis with GC/MS and ICP/MS, was conducted to the nine South Korean wastewater treatment plants (WWTPs). From the chemical analysis and bioassay experiments, heavy metals (i.e., Cu and Zn) were found to be the major compounds causing toxic effects toward D. magna. In the whole effluent toxicity (WET) tests using D. magna, toxicities were observed in 34% of the effluent samples. However, the biological toxic unit (TU) value showed a non-toxic response (i.e., 0 TU) in many samples despite the response indicated by the chemical TU values. This may be due to the species sensitivity, environmental parameters, mixture effects, and limitation of the chemical analyses.