辽宁省三级保护植物木根黄芩考证及其与京黄芩比较形态学研究

木根黄芩(Scutellaria planipes Nakai et Kitag.)是唇形科黄芩属(Scutellaria L.)多年生草本,目前仅发现在辽宁省凌源市境内有零星分布,被辽宁省列为三级保护植物。该种发表于1934年,但《中国植物志》、Flora of China、《中国生物物种名录》均将其定为京黄芩(Scutellaria pekinensis Maxim.)的异名。为了阐明二者的差异性,本文首先对木根黄芩的原始文献、模式标本、模式产地、历史分布区及现今发现地进行考证,其次对二者进行差异比较研究,认为木根黄芩与京黄芩无论在分布范围和生境上,还是在宏观外部形态和微观花粉粒形态上均存在明显差异,确定木根黄芩为独立种,同时还对木根黄芩的果实进行形态补充描述。本文确定木根黄芩独立种的地位,对保护野生木根黄芩具有重要意义,同时对其药用价值的进一步研究提供了更为清晰的样本。     

An analytical study of the factors that influence COVID-19 spread

The outbreak of the coronavirus disease 2019 (COVID-19) continues to constitute an international public health emergency. Seasonality is a long-recognized attribute of many viral infections of humans. Nevertheless, the relationship between environmental factors and the spread of infection, particularly for person-to-person communicable diseases, remains poorly understood. This study explores the relationship between environmental factors and the incidence of COVID-19 in 188 countries with reported COVID-19 cases as of April 13, 2020. Here we show that COVID-19 growth rates peaked in temperate zones in the Northern Hemisphere during the outbreak period, while they were lower in tropical zones. The relationships between COVID-19 and environmental factors were resistant to the potentially confounding effects of air pollution, sea level, and population. To prove the effect of those factors, study, and analysis of the prevalence of COVID-19 in Italy, Spain, and China was undertaken. A fuzzy logic system was designed to predict the effects of that variables on the rate of viral spread of COVID-19.     

Next Generation Semiconductor Based-Sequencing of a Nutrigenetics Target Gene (GPR120) and Association with Growth Rate in Italian Large White Pigs

The GPR120 gene (also known as FFAR4 or O3FAR1) encodes for a functional omega-3 fatty acid receptor/sensor that mediates potent insulin sensitizing effects by repressing macrophage-induced tissue inflammation. For its functional role, GPR120 could be considered a potential target gene in animal nutrigenetics. In this work we resequenced the porcine GPR120 gene by high throughput Ion Torrent semiconductor sequencing of amplified fragments obtained from 8 DNA pools derived, on the whole, from 153 pigs of different breeds/populations (two Italian Large White pools, Italian Duroc, Italian Landrace, Casertana, Pietrain, Meishan, and wild boars). Three single nucleotide polymorphisms (SNPs), two synonymous substitutions and one in the putative 3′-untranslated region (g.114765469C > T), were identified and their allele frequencies were estimated by sequencing reads count. The g.114765469C > T SNP was also genotyped by PCR-RFLP confirming estimated frequency in Italian Large White pools. Then, this SNP was analyzed in two Italian Large White cohorts using a selective genotyping approach based on extreme and divergent pigs for back fat thickness (BFT) estimated breeding value (EBV) and average daily gain (ADG) EBV. Significant differences of allele and genotype frequencies distribution was observed between the extreme ADG-EBV groups (P < 0.001) whereas this marker was not associated with BFT-EBV.     

No association between sperm competition and sperm length variation across dung flies (Scathophagidae)

Sperm length is extremely variable across species, but a general explanation for this variation is lacking. However, when the risk of sperm competition is high, sperm length is predicted to be less variable within species, and there is some evidence for this in birds and social insects. Here, we examined intraspecific variation in sperm length, both within and between males, and its potential associations with sperm competition risk and variation in female reproductive tract morphology across dung flies. We used two measures of variation in sperm size, and testis size was employed as our index of sperm competition risk. We found no evidence of associations between sperm length variation and sperm competition or female reproductive tract variation. These results suggest that variation in sperm competition risk may not always be associated with variation in sperm morphology, and the cause(s) of sperm length variation in dung flies remains unclear.     

Species Differences in Angiotensin II Generation and Degradation by Mast Cell Chymases

Abstract

Although chymases are known to exhibit species differences in regard to angiotensin (Ang) II generation and degradation, their properties have never been compared under the same experimental conditions. We analyzed the processing of Ang I by chymases of a variety of species (human chymase, dog chymase, hamster chymase-1, rat mast cell protease-1 [rMCP-1], mouse mast cell protease-4 [mMCP-4]) at physiological ionic strength and under neutral pH conditions. Human chymase generated Ang II from Ang I without further degradation, whereas the chymases of other species generated Ang II, followed by degradation at the Tyr⁴-Ile⁵ site in a time-dependent manner. Kinetic analysis showed that in terms of Ang II generating activity (analyzed by cleavage of the Phe⁸-His⁹ bond using the model peptide Ang, Ile⁵-His⁶-Pro⁷-Phe⁸-His⁹-Leu¹⁰), the chymases ranked as follows:dog > human > hamster > mouse > rat (k_cat/K_m: 18, 11, 0.69, 0.059, 0.030 μ M^{? 1}min^{? 1}), and that in terms of Ang II degrading activity (i.e., cleavage of the Tyr⁴-Ile⁵ bond of Ang II), the order was hamster > rat > mouse > dog (k_cat/K_m: 5.4, 4.8, 0.39, 0.29 μ M^?1min^?1). These results suggest species differences in the contribution of chymases to local Ang II generation and degradation.     

Hidden areas of endemism: Small units in the South-eastern Neotropics

This study aimed to establish if the Lower Río de la Plata Basin (LRPB) wetlands can be considered a biogeographic unit. The species of this area were compiled and segregated according to the habitat, selecting only 87 endemic taxa restricted to the LRPB and linked to wetlands. Distributional data of species obtained from the literature, web databases, biological collections, and field trips were georeferenced. The areas of endemism were established as those areas where the distribution of two or more taxa overlaps in groups of rivers’ sections with geographic continuity and were tested with a cluster analysis. This congruence is due to ecological, geomorphological, and historical factors. Four areas of endemism were found: a broad area that comprises the whole study area (Riverine district), which is divided into three nested smaller areas (Paraguay–Paraná Flooding Valleys, Uruguay Basin, and Paraná Delta subdistricts). Then, we analysed 170 taxa distributions to evaluate the relationship between the study area and the neighbouring biogeographic units. According to the results, the study area belongs to the Paraná biogeographic province. Some areas of endemism are hidden inside broader areas and are hardly detected with the currently used biogeographic grid-methods. We propose to combine the information about ecological requirements of each taxon with its georeferenced records to estimate their areas of distribution as a primary step for searching areas of endemism in intracontinental studies.     

Structure-activity study of phosphoramido acid esters as acetylcholinesterasf inhibitors

Phosphoramido acid esters (CH₃)₂NP(O)X(p-OC₆H₄-CH₃) (containing P-Cl (1), P-O (2), P-F (3), P-CN (5), and P-N (4,6) bonds, X for 2, 4 and 6 is OCH₃, (C₂H₅)₂N and morpholin) have been synthesized to investigate the structure-activity study of AChE enzyme inhibition, through the parameters logP, δ³¹P and IC₅₀. After their characterization by ³¹P, ³¹P{¹H}, ¹³C, ¹H NMR, IR and mass spectroscopy, the parameters logP and δ³¹P (³¹P chemical shift in NMR) were used to evaluated the lipophilicity and electronical properties. The ability of compounds to inhibit human AChE was predicted by PASS software (version 1.193), and experimentally evaluated by a modified Ellman's assay.     

Treatment planning and dosimetric comparison study on two different volumetric modulated arc therapy delivery techniques

Aim

To compare and evaluate the performance of two different volumetric modulated arc therapy delivery techniques.

Background

Volumetric modulated arc therapy is a novel technique that has recently been made available for clinical use. Planning and dosimetric comparison study was done for Elekta VMAT and Varian RapidArc for different treatment sites.

Materials and methods

Ten patients were selected for the planning comparison study. This includes 2 head and neck, 2 oesophagus, 1 bladder, 3 cervix and 2 rectum cases. Total dose of 50 Gy was given for all the plans. All plans were done for RapidArc using Eclipse and for Elekta VMAT with Monaco treatment planning system. All plans were generated with 6 MV X-rays for both RapidArc and Elekta VMAT. Plans were evaluated based on the ability to meet the dose volume histogram, dose homogeneity index, radiation conformity index, estimated radiation delivery time, integral dose and monitor units needed to deliver the prescribed dose.

Results

RapidArc plans achieved the best conformity (CI_95% = 1.08 ± 0.07) while Elekta VMAT plans were slightly inferior (CI_95% = 1.10 ± 0.05). The in-homogeneity in the PTV was highest with Elekta VMAT with HI equal to 0.12 ± 0.02 Gy when compared to RapidArc with 0.08 ± 0.03. Significant changes were observed between the RapidArc and Elekta VMAT plans in terms of the healthy tissue mean dose and integral dose. Elekta VMAT plans show a reduction in the healthy tissue mean dose (6.92 ± 2.90) Gy when compared to RapidArc (7.83 ± 3.31) Gy. The integral dose is found to be inferior with Elekta VMAT (11.50 ± 6.49) × 10⁴ Gy cm³ when compared to RapidArc (13.11 ± 7.52) × 10⁴ Gy cm³. Both Varian RapidArc and Elekta VMAT respected the planning objective for all organs at risk. Gamma analysis result for the pre-treatment quality assurance shows good agreement between the planned and delivered fluence for 3 mm DTA, 3% DD for all the evaluated points inside the PTV, for both VMAT and RapidArc techniques.

Conclusion

The study concludes that a variable gantry speed with variable dose rate is important for efficient arc therapy delivery. RapidArc presents a slight improvement in the OAR sparing with better target coverage when compared to Elekta VMAT. Trivial differences were noted in all the plans for organ at risk but the two techniques provided satisfactory conformal avoidance and conformation.     

Phytoremediation of 1,4-Dioxane-Containing Recovered Groundwater

The results of a pilot-scale phytoremediation study are reported in this paper. Small plots of trees established on a closed municipal waste landfill site were irrigated with recovered groundwater containing 1,4-dioxane (dioxane) and other volatile organic compounds (VOCs). The plots were managed to minimize the leaching of irrigation water, and leaching was quantified by the use of bromide tracer. Results indicated that the dioxane (2.5 μg/L) was effectively removed, probably via phytovolatilization, and that a full-scale phytoremediation system could be used. A system is now in place at the site in which the recovered groundwater can be treated using two different approaches. A physical treatment system (PTS) will be used during the winter months, and a 12 ha phytoremediation system (stands of coniferous trees) will be used during the growing season. The PTS removes VOCs using an air-stripper, and destroys dioxane using a photo-catalytic oxidation process. Treated water will be routed to the local sewer system. The phytoremediation system, located on the landfill, will be irrigated with effluent from the PTS air-stripper containing dioxane. Seasonal use of the phytoremediation system will reduce reliance on the photo-catalytic oxidation process that is extremely energy consumptive and expensive to operate.