Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinf...Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinforcement is not fully understood.In this study,the influence of soil moisture on root pullout properties was studied by experiments.Vertical in-situ pullout tests under four different levels of soil matric suction(12 kPa,18 kPa,24 kPa,30 kPa)were carried out on roots of sea buckthorn plants(Hippophae rhamnoides Linn.)which were artificially cultivated for 7 months.Diameter and length of the root system of sea buckthorn were investigated.The results showed that a very significant correlation was observed between root diameter(D)and root length(L)(P<0.01),and root diameter decreased with soil depth.When soil bulk density was constant,peak pullout force(F)and friction coefficient of root-soil interface(μ)decreased with increasing gravimetric soil moisture content in power functions.Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil.Root diameter at breakage point(Db)and length of root segment left in soil(Lb)were increased with soil moisture content.In addition,peak pullout force of the roots increased in a power function with root diameter at the soil surface(D0)and in a linear function with total root length(L).The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.展开更多
A Hippophae rhamnoides Linn oil nanoemulsion was developed, and its physicochemical properties and in vitro transdermal characteristics were investigated. Then its skin irritation was investigated. The optimum Hippoph...A Hippophae rhamnoides Linn oil nanoemulsion was developed, and its physicochemical properties and in vitro transdermal characteristics were investigated. Then its skin irritation was investigated. The optimum Hippophae rhamnoides Linn oil nanoemulsion prescription was determined using Cremophor EL as an emulsifier, Transcutol P as a co-emulsifier, and isopropyl myristate(IPM) as the oil phase(IPM%: Cremophor EL%: Hippophae rhamnoides Linn oil%= 5:16:20, Km = 4:1). The prepared Hippophae rhamnoides Linn oil nanoemulsion was pale yellow and transparent. Globular droplets were observed under a transmission electron microscope(TEM). The average particle size was 52.2±4.8 nm. The loading capacity was 10.68%, and the oil-in-water(O/W) type nanoemulsion was stable after centrifugation. The CLSM results showed that the fluorescence intensity of the OB Hippophae rhamnoides Linn oil nanoemulsion group was stronger than that of the Hippophae rhamnoides Linn oil cream and Hippophae rhamnoides Linn oil groups in each layer of skin. The study also showed that skin surface treated with the Hippophae rhamnoides Linn oil nanoemulsion had strong fluorescence. The skin depth had weak fluorescence, while the areas near the hair follicle and its appendages had the strongest fluorescence. The skin irritation test showed that the prepared Hippophae rhamnoides Linn oil nanoemulsion was applied to the normal and damaged skin of the rabbit, and there was no apparent redness and swelling. These results suggested that the nanoemulsion coated with Hippophae rhamnoides Linn oil was a potential delivery system for skin disorders.展开更多
The genus Hippophae includes deciduous shrubs or small trees,which provide many ecological,economic,and social benefi ts.We assembled and annotated the chloroplast genomes of sympatric Hippophae gyantsensis(Rousi)Lian...The genus Hippophae includes deciduous shrubs or small trees,which provide many ecological,economic,and social benefi ts.We assembled and annotated the chloroplast genomes of sympatric Hippophae gyantsensis(Rousi)Lian and Hippophae rhamnoides Linn subsp.yunnanensis Rousi and comparatively analyzed their sequences.The fulllength chloroplast genomes of H.gyantsensis and H.rhamnoides subsp.yunnanensis were 155,260 and 156,415 bp,respectively;both featured a quadripartite structure with two copies of a large inverted repeat(IR)separated by small(SSC)and large(LSC)single-copy regions.Each Hippophae chloroplast genome contained 131 genes,comprising 85 protein-coding,8 ribosomal RNA,and 38 transfer RNA genes.Of 1302 nucleotide substitutions found between these twogenomes,824(63.29%)occurred in the intergenic region or intron sequences,and 478(36.71%)were located in the coding sequences.The SSC region had the highest mutation rate,followed by the LSC region and IR regions.Among the protein-coding genes,three had a ratio of nonsynonymous to synonymous substitutions(Ka/Ks)>1 yet none were signifi-cant,and 66 had Ka/Ks<1,of which 46 were signifi cant.We found 20 and 16 optimal codons,most of which ended with A or U,for chloroplast protein-coding genes of H.gyantsensis and H.rhamnoides subsp.yunnanensis,respectively.Phylogenetic analysis of fi ve available whole chloroplast genome sequences in the family Elaeagnaceae—using one Ziziphus jujube sequence as the outgroup—revealed that all fi ve plant species formed a monophyletic clade with two subclades:one subclade consisted of three Hippophae species,while the other was formed by two Elaeagnus species,supported by 100%bootstrap values.Together,these results suggest the chloroplast genomes among Hippophae species are conserved,both in structure and gene composition,due to general purifying selection;like many other plants,a signifi cant AT preference was discerned for most proteincoding genes in the Hippophae chloroplast genome.This study provides a valuable reference tool for future research on the general characteristics and evolution of chloroplast genomes in the genus Hippophae.展开更多
基金supported by the National Natural Science Foundation of China project(No.31600582)Research Project Supported by Shanxi Scholarship Council of China(2020-054)+1 种基金Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province of China(2017)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2019L0175)。
文摘Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinforcement is not fully understood.In this study,the influence of soil moisture on root pullout properties was studied by experiments.Vertical in-situ pullout tests under four different levels of soil matric suction(12 kPa,18 kPa,24 kPa,30 kPa)were carried out on roots of sea buckthorn plants(Hippophae rhamnoides Linn.)which were artificially cultivated for 7 months.Diameter and length of the root system of sea buckthorn were investigated.The results showed that a very significant correlation was observed between root diameter(D)and root length(L)(P<0.01),and root diameter decreased with soil depth.When soil bulk density was constant,peak pullout force(F)and friction coefficient of root-soil interface(μ)decreased with increasing gravimetric soil moisture content in power functions.Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil.Root diameter at breakage point(Db)and length of root segment left in soil(Lb)were increased with soil moisture content.In addition,peak pullout force of the roots increased in a power function with root diameter at the soil surface(D0)and in a linear function with total root length(L).The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.
基金National Natural Science Foundation of China(Grant No.81460539)the excellent postgraduate project in Xinjiang Medical University(Grant No.CXCY096)
文摘A Hippophae rhamnoides Linn oil nanoemulsion was developed, and its physicochemical properties and in vitro transdermal characteristics were investigated. Then its skin irritation was investigated. The optimum Hippophae rhamnoides Linn oil nanoemulsion prescription was determined using Cremophor EL as an emulsifier, Transcutol P as a co-emulsifier, and isopropyl myristate(IPM) as the oil phase(IPM%: Cremophor EL%: Hippophae rhamnoides Linn oil%= 5:16:20, Km = 4:1). The prepared Hippophae rhamnoides Linn oil nanoemulsion was pale yellow and transparent. Globular droplets were observed under a transmission electron microscope(TEM). The average particle size was 52.2±4.8 nm. The loading capacity was 10.68%, and the oil-in-water(O/W) type nanoemulsion was stable after centrifugation. The CLSM results showed that the fluorescence intensity of the OB Hippophae rhamnoides Linn oil nanoemulsion group was stronger than that of the Hippophae rhamnoides Linn oil cream and Hippophae rhamnoides Linn oil groups in each layer of skin. The study also showed that skin surface treated with the Hippophae rhamnoides Linn oil nanoemulsion had strong fluorescence. The skin depth had weak fluorescence, while the areas near the hair follicle and its appendages had the strongest fluorescence. The skin irritation test showed that the prepared Hippophae rhamnoides Linn oil nanoemulsion was applied to the normal and damaged skin of the rabbit, and there was no apparent redness and swelling. These results suggested that the nanoemulsion coated with Hippophae rhamnoides Linn oil was a potential delivery system for skin disorders.
基金the National Natural Science Foundation of China(31670666)the Fundamental Research Funds for the Central Non-profit Research Institution of Chinese Academy of Forestry(ZDRIF201706).
文摘The genus Hippophae includes deciduous shrubs or small trees,which provide many ecological,economic,and social benefi ts.We assembled and annotated the chloroplast genomes of sympatric Hippophae gyantsensis(Rousi)Lian and Hippophae rhamnoides Linn subsp.yunnanensis Rousi and comparatively analyzed their sequences.The fulllength chloroplast genomes of H.gyantsensis and H.rhamnoides subsp.yunnanensis were 155,260 and 156,415 bp,respectively;both featured a quadripartite structure with two copies of a large inverted repeat(IR)separated by small(SSC)and large(LSC)single-copy regions.Each Hippophae chloroplast genome contained 131 genes,comprising 85 protein-coding,8 ribosomal RNA,and 38 transfer RNA genes.Of 1302 nucleotide substitutions found between these twogenomes,824(63.29%)occurred in the intergenic region or intron sequences,and 478(36.71%)were located in the coding sequences.The SSC region had the highest mutation rate,followed by the LSC region and IR regions.Among the protein-coding genes,three had a ratio of nonsynonymous to synonymous substitutions(Ka/Ks)>1 yet none were signifi-cant,and 66 had Ka/Ks<1,of which 46 were signifi cant.We found 20 and 16 optimal codons,most of which ended with A or U,for chloroplast protein-coding genes of H.gyantsensis and H.rhamnoides subsp.yunnanensis,respectively.Phylogenetic analysis of fi ve available whole chloroplast genome sequences in the family Elaeagnaceae—using one Ziziphus jujube sequence as the outgroup—revealed that all fi ve plant species formed a monophyletic clade with two subclades:one subclade consisted of three Hippophae species,while the other was formed by two Elaeagnus species,supported by 100%bootstrap values.Together,these results suggest the chloroplast genomes among Hippophae species are conserved,both in structure and gene composition,due to general purifying selection;like many other plants,a signifi cant AT preference was discerned for most proteincoding genes in the Hippophae chloroplast genome.This study provides a valuable reference tool for future research on the general characteristics and evolution of chloroplast genomes in the genus Hippophae.
