114 research outputs found

    On Generalization and Computation of Tukey's Depth: Part I

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    Tukey's depth offers a powerful tool for nonparametric inference and estimation, but also encounters serious computational and methodological difficulties in modern statistical data analysis. This paper studies how to generalize and compute Tukey-type depths in multi-dimensions. A general framework of influence-driven polished subspace depth, which emphasizes the importance of the underlying influence space and discrepancy measure, is introduced. The new matrix formulation enables us to utilize state-of-the-art optimization techniques to develop scalable algorithms with implementation ease and guaranteed fast convergence. In particular, half-space depth as well as regression depth can now be computed much faster than previously possible, with the support from extensive experiments. A companion paper is also offered to the reader in the same issue of this journal

    A review of argasid ticks and associated pathogens of China

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    It has been recorded 221 species of soft ticks in the world. However, the classification system of Argasidae is still unclear with nearly two-third controversial species in genus level. Therefore, comprehensive research is still necessary. In 2016, Wen and Chen overviewed the valid species of soft ticks in China for the first time. Up to now, the soft tick fauna of China remains poorly known. Although several studies have been undertaken, the information regarding soft ticks and associated diseases are fragmentary. To facilitate the future study of this group, the scattered information on soft ticks of China is herein synthesized. Toward the end of 2021, 15 valid species of argasid ticks have been reported, of these, 9 species (60%) including Argas beijingensis, A. japonicus, A. persicus, A. sinensis, A. vespertilionis, A. vulgaris, Ornithodoros lahorensis, O. tartakovskyi, and O. papillipes have been recorded biting humans. Argas persicus is the most common species, and its borne pathogens are widely investigated, while most other argasid ticks are not sufficiently studied in China. Here, we summarize detailed information regarding hosts, geographical distribution, molecular data, and vector roles of argasid ticks in China

    Influence of Croton tiglium seeds on the pharmacokinetics of anthraquinones in Radix et Rhizoma Rhei

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    In this study, the influence of Croton tiglium seeds on the pharmacokinetic of rhein in Radix et Rhizoma Rhei was performed to elucidate the compatibility relationship of these two herbs. The pharmacokinetics of rhein was studied following oral administration of pure rhein, Radix et Rhizoma Rhei methanol extract (RE) and Radix et Rhizoma Rhei and seeds of Croton tiglium mathanol extract (RCE), with approximately the same dose of 10mg/kg. It was found that comparing with that in monomer, both AUC and Cmax of rhein in RE and different proportion of RCE were significantly different. The results indicated that comparing with the monomer, the concentration of rhein in the plasma was increased in the group of RE whereas the tendency of AUC and Cmax of rhein in RCE presented quite discrepancy depending on the different proportion of RCE.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Biotransformation of rhizoma Paridis saponins by rat intestinal microflora

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    Rhizoma Paridis saponins (RPS) were considered to be the principal bioactive components of Paris polyphylla Smith var. yunnanensis. Intestinal microflora-mediated metabolism may affect their pharmacological activities in vivo. In this study, the biotransformation of RPS by rat intestinal microflora in vitro was investigated. A high-performance liquid chromatography with electrospray ionization combined with mass spectrometry (HPLC-ESI-MS) method was developed to identify RPS and their metabolites. The metabolism of RPS by rat intestinal microflora was mainly based on cleavage of the oligosaccharide chains which is connected to the C-3 or C-22 position. However, the elimination of the glucose molecule at C-26 and F-ring closure occurred firstly in prototype saponins. In addition, the biotransformation routes of RPS in the presence of rat intestinal microflora were elaborated, from which RPS were presumed primarily responsible for the metabolism via α-rhamnosidase and β-glycosidase activities. These results would contribute to understanding of the mechanisms in bioavailability of herbal drugs and their metabolites.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Influence of Croton tiglium seeds on the pharmacokinetics of anthraquinones in Radix et Rhizoma Rhei

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    In this study, the influence of Croton tiglium seeds on the pharmacokinetic of rhein in Radix et Rhizoma Rhei was performed to elucidate the compatibility relationship of these two herbs. The pharmacokinetics of rhein was studied following oral administration of pure rhein, Radix et Rhizoma Rhei methanol extract (RE) and Radix et Rhizoma Rhei and seeds of Croton tiglium mathanol extract (RCE), with approximately the same dose of 10mg/kg. It was found that comparing with that in monomer, both AUC and Cmax of rhein in RE and different proportion of RCE were significantly different. The results indicated that comparing with the monomer, the concentration of rhein in the plasma was increased in the group of RE whereas the tendency of AUC and Cmax of rhein in RCE presented quite discrepancy depending on the different proportion of RCE.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Species delimitation of the Dermacentor ticks based on phylogenetic clustering and niche modeling

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    Three species belonging to the genus Dermacentor (Acari: Ixodidae), D. marginatus, D. nuttalli and D. silvarum are well known as vectors for a great variety of infection pathogens. All three of them are host ticks, which are very similar in morphology characteristics, life cycle, seasonal variation and ecological conditions, making it difficult to distinguish the three species. In the present study, these three species were delimitated based on molecular data and ecological niche. The molecular analysis showed that the three species can be distinguished by COI and ITS2 sequences. We created future potential distribution maps for the three species under climate changes with MaxEnt, which highlighted the different levels of the suitable habitats for each tick species. In addition, niche comparisons among the three species in Dermacentor were conducted, and the analysis suggested that niche overlap was relatively high with D. nuttalli and D. silvarum compared to the other species pairs, which was consistent with the molecular data. Niche equivalency and similarity test confirmed that these Dermacentor species were closely related but distinct species. In conclusion, delimitation of these three species within Dermacentor was supported by molecular phylogeny and quantitative ecological space. This study will provide deep insights into the biology, ecology, and diversification processes within Dermacentor species, and for the development of effective control for ticks

    Glycyrrhizic acid-phospholipid complex: preparation process optimization and therapeutic and pharmacokinetic evaluation in rats

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    The purpose of the present study was to prepare glycyrrhizic acid-phospholipid complex (GL-PLC) as to improve the oral bioavailability of glycyrrhizic acid (GL), enhance the drug efficacy and reduce the side effects. The uniform experimental design approach was utilized for the process optimization in order to obtain the satisfactory complex. The results of comparison between GL-PLC and free GL indicated that the anti-inflammatory activity of the phospholipid complex was significantly higher than that of free GL at the same dose. The results of pharmacokinetic study displayed that the plasma concentration of glycyrrhetic acid, the metabolite of GL in vivo, increased after oral administration of GL-PLC. The Cmax of GL-PLC was 2.14 times higher than that of free glycyrrhizic acid, while the AUC of GL-PLC was 1.74 times higher than that of free GL. The results proved that GL-PLC improved the lipophilic property of GL, increased the bioavailability and anti-inflammatory activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Comprehensive Analysis of the Global Protein Changes That Occur During Salivary Gland Degeneration in Female Ixodid Ticks Haemaphysalis longicornis

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    Ticks are notorious blood-sucking arthropods that can spread a variety of pathogens and cause great harm to the health of humans, wildlife and domestic animals. The salivary glands of female ticks degenerate rapidly when the ticks reach critical weight or become engorged, which can be caused by hormones and by the synergistic effects of multiple proteins. To explore the complex molecular mechanisms of salivary gland degeneration in ticks, this study applies iTRAQ quantitative proteomic technology for the first time to study changes in protein expression in the salivary glands of female Haemaphysalis longicornis during the process of degeneration and to search for proteins that play an important role in salivary gland degeneration. It was found that the expression of some proteins associated with energy production was continuously down-regulated during salivary gland degeneration, while some proteins associated with DNA or protein degradation were consistently up-regulated. Furthermore, the expression of some proteins related to cell apoptosis or autophagy was also changed. These proteins were knocked down by RNAi to observe the phenotypic and physiological changes in female ticks. The results showed that the time required for engorgement and the mortality rates of the female ticks increased after RNAi of F0F1-type ATP synthase, NADH-ubiquinone oxidoreductase, cytochrome C, or apoptosis-inducing factor (AIF). The corresponding engorged weights, oviposition amounts, and egg hatching rates of the female ticks decreased after RNAi. Interference of the expression of AIF in engorged ticks by RNAi showed that the degeneration of salivary glands of female ticks was slowed down

    Molecular Characterization of Haemaphysalis Species and a Molecular Genetic Key for the Identification of Haemaphysalis of North America

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    Haemaphysalis longicornis (Acari: Ixodidae), the Asian longhorned tick, is native to East Asia, but has become established in Australia and New Zealand, and more recently in the United States. In North America, there are other native Haemaphysalis species that share similar morphological characteristics and can be difficult to identify if the specimen is damaged. The goal of this study was to develop a cost-effective and rapid molecular diagnostic assay to differentiate between exotic and native Haemaphysalis species to aid in ongoing surveillance of H. longicornis within the United States and help prevent misidentification. We demonstrated that restriction fragment length polymorphisms (RFLPs) targeting the 16S ribosomal RNA and the cytochrome c oxidase subunit I (COI) can be used to differentiate H. longicornis from the other Haemaphysalis species found in North America. Furthermore, we show that this RFLP assay can be applied to Haemaphysalis species endemic to other regions of the world for the rapid identification of damaged specimens. The work presented in this study can serve as the foundation for region specific PCR-RFLP keys for Haemaphysalis and other tick species and can be further applied to other morphometrically challenging taxa
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