Thuja Research Articles

Simultaneous preconcentration and determination of trace flavonoids in complex matrix by phosphatidylcholine supramolecular solvent-based dispersive liquid-phase microextraction

A new phosphatidylcholine supramolecular solvent dispersive liquid-phase microextraction (PCSS-DLPME) combined with high-performance liquid chromatography was first developed and introduced for simultaneous preconcentration and determination of the trace flavonoids (myricetin, quercetin, isorhamnetin, baicalein, wogonin, kaempferide) in Ginkgobiloba, Platycladus orientalis and Scutellaria. In this study, a supramolecular solvent formed by self- assembly of an amphoteric biosurfactant phosphatidylcholine and chloroform was used as the extraction phase in DLPME, and the six flavonoids were extracted from herbal aqueous samples into the supramolecular solvent. The crucial parameters affecting the enrichment factors of target analytes, such as type of organic solvent in PCSS, phosphatidylcholine content in PCSS, type of dispersant, pH of sample phase, concentration of salt, volume of PCSS, shaking time, centrifugation rate and time were investigated and optimized. Under the optimum conditions, the analytes’ EFs were between 107.6 and 205.3, better linearities (r ≥ 0.9927) were obtained, the limits of detection were 0.15–0.5 ng/mL, satisfactory precisions (relative standard deviation were 1.7–11.2%) and average recoveries (87.6%–104.4%) were achieved. This method has the advantages of simple and convenient preparation of supramolecular solvent, high enrichment, good sensitivity and selectivity for flavonoids, which was suitable for the analysis of trace substances in complex matrix.

Deep soil moisture limits the sustainable vegetation restoration in arid and semi-arid Loess Plateau

Deep soil moisture (DSM) (>100 cm) in water-limited regions usually functions as a soil reservoir and plays a vital role in plant productivity and ecosystem sustainability. However, the regional impacts of revegetation on the dynamics of DSM and the sustainability of restoration remain essentially unknown. This paper synthesized 94 peer-reviewed publications containing 5668 observations from 55 sites that focused on cropland, natural grassland, planted shrubs and planted forests on the Chinese Loess Plateau to identify the regional impacts of revegetation on the DSM under different restoration periods and precipitation gradients. The results showed the following: (1) Planted forests and shrubs exerted a strong negative impact on DSM within the 1000-cm depth in which the average soil moisture in 100–500 cm was lower than the average permanent wilting point (8.6%), the choice of tree species greatly influenced the DSM depletion extent, and Platycladus orientalis and Hippophae rhamnoides were recommended to maintain a better DSM condition. (2) The temporal pattern of DSM dynamics within the 1000-cm depth under planted forests and shrubs exhibited a significant and continuous decrease in first 20 years and remained relatively stable after 20 years, in which the soil moisture was lower than the average permanent wilting point, and grassland showed no obvious trends among different restoration periods (0–30 yr). (3) The limiting effects of precipitation changed greatly along the soil profile under planted forests and shrubs, and the restrictions may begin to appear when the mean annual precipitation is less than 480 mm when considering the deep soil layer (200–1000 cm). (4) The change rate of DSM within 1000 cm in planted forests (−0.08 to −0.11 g 100 g−1 yr−1) and planted shrubs (−0.05 to −0.20 g 100 g−1 yr−1) was much higher than that in natural grassland (−0.02 to −0.07 g 100 g−1 yr−1). Our results demonstrate that in arid and semiarid regions, the DSM in planted forests and shrubs was lower than or approached the average permanent wilting point and might limit the sustainability of vegetation restoration. When considering the joint effects between precipitation and vegetation type in deep soil layers, planted forests and shrubs are acceptable only when precipitation is greater than 480 mm, while grassland may be the best restoration type if precipitation is less than 480 mm.

Effect of Phytoremediation on Geotechnical Characteristics of Oil Contaminated Sands

ABSTRACT The environmental contaminations occurred by exploration, drilling, extraction, transportation and storage of different substances for using in industries have serious effects on soils and their properties. This research examined the effects of phytoremediation on the removal of total petroleum hydrocarbons (TPHs) and geotechnical properties of a silty clayey sand contaminated by 3%, 5%, and 7% crude oil. Ophiopogon japonicus and Platycladus orientalis were two types of plants used to determine the phytoremediation effects within 30 and 60 days of operation. The scanning electron microscopy (SEM) images indicated that with increase in crude oil content at 0, 30, and 60 days of investigations, the soil particles become more flocculated. Comparison of the soil samples that experienced phytoremediation and without phytoremediation showed that flocculation of the soil particles became less during phytoremediation process. Use of Platycladus orientalis reduced soil flocculation more compared to Ophiopogon japonicus. The test results also showed that the TPHs removal rate using Platycladus orientalis was more than Ophiopogon japonicus. The addition of more crude oil contents caused enhancement of permeability while liquid limit, plastic limit, maximum dry density, optimum moisture content and CBR decreased. Investigation of the geotechnical properties of soil at different crude oil contents in 30 and 60 days of phytoremediation revealed that soil samples that experienced phytoremediation had more CBR and lower permeability compared to other ones without phytoremediation. It was also observed that upon more days of phytoremediation the liquid limit, plastic limit, optimum moisture content and permeability increased while the maximum dry density decreased. Using Platycladus orientalis compared to Ophiopogon japonicus yielded higher liquid limit, plastic limit, maximum dry density, and CBR along with lower optimum moisture content and permeability.

Hair Growth Promoting Activity of Cedrol Nanoemulsion in C57BL/6 Mice and Its Bioavailability.

As the main component of Platycladus orientalis, cedrol has known germinal activity. A range of cedrol formulations have been developed to prevent hair-loss, but compliance remains key issues. In this study, we prepared cedrol nanoemulsion (CE-NE) and determined the particle size and PDI (polydispersion coefficient), investigated the hair growth activity and studied the bioavailability in vitro and in vivo. Results showed that the average particle size of CE-NE is 14.26 ± 0.16 nm, and the PDI value is 0.086 ± 0.019. In vitro drug release investigation and drug release kinetics analysis showed release profile of CE from nanoparticles demonstrates the preferred partition of CE in buffer pH 4.0, the release profile of CE-NE showed a first-order kinetics reaching around 36.7% after 6 h at 37 °C. We artificially depilated the back hair of C57BL/6 mice and compared the efficacy of a designed cedrol nanoemulsion to an existing ointment group. The hair follicles were imaged and quantified using a digital photomicrograph. The results showed that compared with the ointment, CE-NE had positive effects on hair growth, improved drug solubility. Compared with the ointment and 2% minoxidil groups, 50 mg/mL CE-NE led to more robust hair growth. Pharmacokinetics analysis showed that the AUC0–t of CE-NE was 4-fold higher than that of the ointment group, confirming that the bioavailability of the nanoemulsion was greater than that of the ointment. CE-NE also significantly reduced the hair growth time of model mice and significantly increased the growth rate of hair follicles. In conclusion, these data suggest that the nanoemulsion significantly improved the pharmacokinetic properties and hair growth effects cedrol, enhancing its efficacy in vitro and in vivo.

Fruit extracts from Phyllanthus emblica accentuate cadmium tolerance and accumulation in Platycladus orientalis: A new natural chelate for phytoextraction.

A key challenge for phytoextraction is the identification of high efficiency, growth-supporting, and low cost chelating agents. To date, no substance has satisfied all above criteria. This study investigated nine traditional Chinese herbs and found that Phyllanthus emblica fruit (FPE) extract could be utilised as an optimal chelate for the phytoextraction of cadmium (Cd)-contaminated soils. FPE application into soil at a ratio of 0.1% (w/w) significantly increased extractable Cd (by 43%) compared to the control. The success of FPE as a chelating agent was attributed to high quantities of polyphenol compounds (0.76%) and organic acids (9.6%), in particular, gallic acid (7.6%). Furthermore, antioxidative properties (1.4%) and free amino acids in FPE alleviated Cd-induced oxidant toxicity and enhanced plant biomass. FPE promoted 78% higher phytoextraction efficiency in Platycladus orientalis compared to traditional chelating agents (EDTA). Furthermore, 76% of FPE was degraded 90 days after the initial application, and there was no difference in extractable Cd between the treatment and control. FPE has been commercially produced at a lower market price than other biodegradable chelates. As a commercially available and cost-effective chelator, FPE could be utilised to treat Cd-contaminated soils without adverse environmental impacts.

A hypomyelinating leukodystrophy in German Shepherd dogs

BackgroundShaking puppy syndrome is commonly attributed to abnormal myelination of the central nervous system.Hypothesis/ObjectivesTo report the long‐term clinical course and the imaging characteristics of hypomyelinating leukodystrophy in German Shepherd dogs.Animals and MethodsThree related litters with 11 affected dogs.ResultsThe 11 affected dogs experienced coarse, side‐to‐side tremors of the head and trunk, which interfered with normal goal‐oriented movements and disappeared at rest. Signs were noticed shortly after birth. Nine dogs were euthanized, 3 dogs underwent pathological examination, and 2 littermates were raised by their breeder. Tremors improved gradually until 6 to 7 months of age. Adult dogs walked with severe residual pelvic limb ataxia. One dog developed epilepsy with tonic‐clonic seizures at 15 months of age. Conventional magnetic resonance imaging (MRI) disclosed homogenous hyperintense signal of the entire subcortical white matter in 3 affected 7‐week‐old dogs and a hypointense signal in a presumably unaffected littermate. Subcortical white matter appeared isointense to gray matter at 15 and 27 weeks of age on repeated MRI. Abnormal white matter signal with failure to display normal gray‐white matter contrast persisted into adulthood. Cerebellar arbor vitae was not visible at any time point. Clinical signs, MRI findings, and pathological examinations were indicative of a hypomyelinating leukodystrophy. All parents of the affected litters shared a common ancestor and relatedness of the puppies suggested an autosomal recessive mode of inheritance.ConclusionWe describe a novel hypomyelinating leukodystrophy in German Shepherd dogs with a suspected inherited origin.

Brachytydeus armindae (Momen & Lundqvist, 2005); a new tydeid record (Acari : Prostigmata), with a revised key to Brachtydeus Thor species of Turkey

Tydeoidea species (Acari: Prostigmata) are little and soft-bodied creatures and globally distributed. In the world, Tydeidae comprises 328 species in 30 genera, and Brachytydeus has the most number of species with 200. Tydeoidea presented by 23 species while Brachytydeus comprises eight species, gathered in orchards and shrub trees in Turkey. Brachytydeus armindae (Momen & Lundqvist 2005) (Acari: Tydeidae), found in association with Thuja orientalis L. (Cupressaceae) trees and stored wheat, is reported as a new species of tydeid fauna of Turkey. Distribution and host details of B. armindae are provided along with descriptive photos and illustrations. An updated key to Brachytydeus Thor species is given.

Foliar endophytes in trees varying greatly in age

Temple trees, including the gymnosperm Platycladus orientalis and the angiosperm Styphnolobium japonicum, have been planted in China for thousands of years. Tree age thus varies widely from young to ancient trees. Foliar endophytes of P. orientalis and S. japonicum were surveyed in this exploratory study that was based on isolation into culture and sequencing of fungi from trees varying in age from 10 to 5000 years (P. orientalis) and from 10 to 1700 years (S. japonicum). Sequenced endophytes of P. orientalis and S. japonicum belonged to 24 and 16 fungal genera, respectively. Principal components analysis showed that 14 components were necessary to explain 90% of the variance in endophyte community structure in P. orientalis. In S. japonicum eight components were needed for 90%. It is against that backdrop of complex etiology in community structuring, that the relative frequencies (abundances) of 17 of the 24 endophytes from P. orientalis and 9 of the 16 from S. japonicum were significantly correlated with tree age. There were two major trends. Abundant fungal genera [Fusarium + Alternaria = 74.57% (P. orientalis) and 81.24% (S. japonicum)] tended to decline linearly with tree age. Most of the rare fungal genera, in contrast, increased in relative abundance linearly with tree age. Diversity (H′) and richness (Margalef) of endophyte communities in foliage thus increased as the trees aged. Relative abundances of pathogenic endophytes, or latent pathogens, (Pestalotiopsis funerea and Amyloporia subxantha in P. orientalis; Collectotrichum gloeosporioides and Botryosphaeria dothidea in S. japonicum) also increased linearly as the trees aged.Since leaf age does not vary with tree age in the deciduous S. japonicum, nor in the evergreen P. orientalis, ‘tree age’ currently lacks a mechanistic explanation for its apparent importance among common foliar endophytes.

Effect of phytoremediation on the shear strength characteristics of silty clayey sand

Pollution of the environment by crude oil is a global problem that changes the geotechnical properties of soil, including its shear strength. In this study, the effects of phytoremediation of soil contaminated with crude oil have been investigated using Ophiopogon japonicus and Platycladus orientalis. The results of phytoremediation were tested at 30 and 60 days of treatment. The results were compared with samples that had not undergone phytoremediation. The soil shear strength parameters were determined using unconsolidated undrained triaxial compression tests at confining pressures of 50, 100, and 150 kPa. The results showed that an increase in the crude oil content led to a decrease in deviatoric stress at failure associated to an axial strain level of 20%. The deviatoric stress in the treated samples was about 15% higher than the samples without phytoremediation. The internal friction angle and cohesion decreased as the crude oil content increased. This decrease was less in the remediated samples, especially those exposed to P. orientalis. The results of the triaxial compression tests revealed the positive effect of phytoremediation in reducing the negative effects of crude oil on the soil shear strength characteristics. SEM images of the contaminated soil samples showed that soil flocculation initially increased with an increase in the crude oil content and time and then decreased subsequent to the application of phytoremediation.

Network pharmacology study on the mechanism of the herb pair of prepared Rehmannia root-Chinese arborvitae kernel for anxiety disorders.

Although anxiety disorders are one of the most common mental illness in population, antianxiety drugs often only have single action targets, require long-term use, and are associated with many adverse reactions and dependencies. Professor Yan Zhaojun from Shandong Provincial Hospital of Traditional Chinese Medicine (TCM) has applied the modified Renshu Powder, a TCM formula, to treat anxiety disorders, with satisfactory outcomes. Here, we investigated the mechanism of action of two core herbs (prepared Rehmannia root and Chinese arborvitae kernel) in the Renshu Powder in the treatment of anxiety disorders by using network pharmacology approaches. Candidate compounds of the herb pair of prepared Rehmannia root-Chinese arborvitae kernel were extracted via the Traditional Chinese Medicine Systems Pharmacology (TCMSP) platform. The targets of action of the main compounds were collected using the SwissTargetPrediction database. Targets associated with anxiety disorders were retrieved from DisGeNET, Online Mendelian Inheritance in Man (OMIM), DrugBank, GeneCards, and Comparative Toxicogenomics Database (CTD) databases. The compound-target interaction network was constructed by Cytoscape 3.7.2 software, and the protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) platform. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses the data by using Metascape. The main active compounds of the herb pair included arachidonic acid, stigmasterol, and beta-sitosterol. The key targets included Nitric Oxide Synthase 3 (NOS3), Epidermal growth factor (EGF), Prostaglandin-Endoperoxide Synthase 2 (PTGS2), Caspase 3 (CASP3), Mitogen-Activated Protein Kinase 1 (MAPK1), Peroxisome proliferator-activated receptor gamma (PPARG), RELA Proto-Oncogene, NF-KB Subunit (RELA), Estrogen Receptor 1 (ESR1), Solute Carrier Family 6 Member 4 (SLC6A4), and Phosphatase and Tensin homolog deleted on chromosome 10 (PTEN). Anxiety disorder-related GO analysis mainly involved synaptic signaling, neurotransmitter receptor activity, and G protein-coupled neurotransmitter receptor activity. The KEGG pathways involved neuroactive ligand-receptor interaction, serotonergic synapse, PI3K/AKT/mTOR signaling pathway, and MAPK signaling pathway. The mechanism of action of the prepared Rehmannia root-Chinese arborvitae kernel in treating anxiety disorders involves multiple ingredients, multiple targets, and pathways.

Changes in runoff in a typical temperate continental-monsoon transitional zone in the last four centuries

Temperate continental-monsoon transitional zones are sensitive to variations in the global hydrological climate, and the long-term patterns of hydrological variability in this zone should be explored urgently. In this study, based on the tree-ring width of Platycladus orientalis, we reconstructed the annual runoff sequence during 1666–2016 (351 years) on Wula Mountain, which lies within the low-latitude temperate continental-monsoon transitional zone. Our reconstruction model is stable and reliable because our reconstruction results overlap well with the arid and flood years and periods found in local historical records. Our analysis results show that over the last four centuries, the annual runoff in the low-latitude transitional zone is characterized by an overall decrease, with heightened fluctuations. Specifically, in the 18th century, wet and extremely wet years appeared frequently, while continuous wet periods grew progressively shorter. Later, this area experienced a mean-flow period of approximately 100 years ending in the 1930 s, when progressively longer dry periods began to occur. In the last 30 years, this area has suffered from its longest dry period in 351 years. Regarding runoff variability, over two centuries in the temperate continental-monsoon transitional zone, high-latitude areas had more wet periods with significant variation in large-scale periodicities; the majority of the zone had simultaneous variation in wetting and drying and a significant drying trend in the first half of the 20th century. High- and low-latitude areas had long and slowly changing arid periods, while mid-latitude areas had short and quickly changing arid periods. This study enriches the understanding of the dendrohydrology of the low and middle latitudes of the temperate continental-monsoon transition zone, analyzes the runoff variations throughout the transition zone area, and helps reconstruct the long-term historical runoff sequence over four centuries in the transitional zone.

Assessment of Cytospora Isolates From Conifer Cankers in China, With the Descriptions of Four New Cytospora Species.

Cytospora species are widely distributed and often occur as endophytes, saprobes or phytopathogens. They primarily cause canker and dieback diseases of woody host plants, leading to the growth weakness or death of host plants, thereby causing significant economic and ecological losses. In order to reveal the diversity of Cytospora species associated with canker and dieback diseases of coniferous trees in China, we assessed 11 Cytospora spp. represented by 28 fungal strains from symptomatic branches or twigs of coniferous trees, i.e., Juniperus procumbens, J. przewalskii, Picea crassifolia, Pinus armandii, P. bungeana, Platycladus orientalis in China. Through morphological observations and multilocus phylogeny of ITS, LSU, act, rpb2, tef1-α, and tub2 gene sequences, we focused on four novel Cytospora species (C. albodisca, C. discostoma, C. donglingensis, and C. verrucosa) associated with Platycladus orientalis. This study represented the first attempt to clarify the taxonomy of Cytospora species associated with canker and dieback symptoms of coniferous trees in China.

Influences of different afforestation systems on the soil properties of limestone mountains in the mid-eastern region of China

Limestone mountain ecosystem degradation has resulted in decreased soil fertility, low water holding capacity, and low biomass productivity. Afforestation has been proposed as an effective method to improve soil properties, however, scant information is available. In this study, the influence of Platycladus orientalis (PO), Broussonetia papyrifera (BP), a mixed shrub dominated by Ziziphus jujuba, Viter negundo (ZV) and a mixed shrub-grass dominated by V. negundo cannabifolia and Arthraxon hispidus (VA) on soil properties at two depth levels (0–10 cm; 10–20 cm) was assessed. This study demonstrates that compared with VA and ZV, PO and BP had higher soil bulk density and subsoil and lower soil water content. A similar trend was observed in the soil content of organic carbon, total nitrogen and total phosphorus with the overall highest and lowest values found in ZV and BP, respectively. These soil nutrients also differed between the two soil layers; however, total soil phosphorus, soil organic carbon and total nitrogen content in PO were markedly higher in topsoil than in subsoil. The available soil nitrogen of ZV was the highest, followed by VA, PO and BP, and significant differences were also detected among them. The available soil phosphorus content did not differ by vegetation type, whereas its content in topsoil was notably higher than in subsoil at all sites. However, the marked difference between topsoil and subsoil was observed only for available potassium but not total potassium. Our study reveals the differential impacts of vegetation type on soil properties in a degraded limestone mountain ecosystem. The use of native shrubs and grasses can increase soil fertility and could be an alternative to the afforestation plan to rehabilitate a degraded limestone mountain area in the mid-eastern region of China.

Аутфітосозологічне оцінювання дендроекзотів відділу Pinophyta ботанічного саду Чернівецького національного університету імені Юрія Федьковича

Здійснено інтегральне аутфітосозологічне оцінювання 41 виду деревних інтродуцентів відділу Pinophyta, які ростуть у ботанічному саду Чернівецького національного університету ім. Юрія Федьковича в умовах відкритого ґрунту. Відповідно до значень вирахуваного для кожного виду аутфітосозологічного індексу досліджувані дендроекзоти віднесено до чотирьох аутфітосозологічних класів (II-V); найбільше видів (27) увійшли до ІІІ класу. Для рослин кожного із аутфітосозологічних класів охарактеризовано ознаки, які найістотніше впливають на фітосозологічну цінність видів: категорія раритетності у Червоному списку МСОП, фітогеографічне та історичне значення, регіональна репрезентативність та кількість штучних природоохоронних об'єктів у межах Чернівецької області, де росте той чи інший вид. Зокрема, найчастіше у дендропарках, парках-пам'ятках садово-паркового мистецтва та у складі пам'яток природи Чернівецької області трапляються Thuja occidentalis L. (30 місцезростань), Pinus strobus L. (22), Platycladus orientalis (L.) Franco (19 місцезростань), і в межах 12-14 природоохоронних об'єктів – Pinus nigra J. F. Arnold, Ginkgo biloba L., Chamaecyparis pisifera (Siebold & Zucc.) Endl. Відзначено, що 51,2 % із досліджуваних видів трапляються, окрім ботанічного саду Чернівецького національного університету, також у дендропарках, парках-пам'ятках садово-паркового мистецтва та пам'ятках природи місцевого значення Чернівецької області. Раритетні види деревних інтродуцентів відділу Pinophyta цінні як резерв генетичного матеріалу. Тому особливої охорони потребують ті з них, які перебувають під загрозою зникнення (категорія раритетності у Червоному списку МСОП – CR, EN та VU), а також ті, що увійшли до ІІ аутфітосозологічного класу (Taxodium distichum (L.) Rich., Sequoiadendron giganteum (Lindl.) J. Buchholz, Metasequoia glyptostroboides Hu & W. C. Cheng, Picea koyamae Shiras.), та частина видів, віднесених до ІІІ класу (зокрема, ті з них, які представлені 1-2 особинами лише у ботанічному саду Чернівецького національного університету, і не здатні розмножуватися насіннєвим шляхом). Під час розроблення рекомендацій з ефективної охорони досліджуваних деревних інтродуцентів варто звертати увагу на екологічні вимоги видів, оскільки від цього значною мірою залежить успішність росту і розвитку інтродуцентів.

Volatile Oil of Platycladus Orientalis (L.) Franco Leaves Exerts Strong Anti-inflammatory Effects via Inhibiting the IκB/NF-κB Pathway

This study was designed to investigate the anti-inflammatory effects of volatile oil of Platycladus orientalis (L.) Franco leaves (VOPF) and the underlying molecular mechanisms by using the non-infectious inflammation rat models and infectious inflammation mouse models. Ear swelling and intraperitoneal capillary permeability in mice, and carrageenan-induced toe swelling and cotton ball-induced granuloma in rats were used to reveal anti-inflammatory effects of VOPF. Moreover, the lipopolysaccharide (LPS)-induced mouse model of acute lung injury was used to explore the anti-inflammatory mechanism of VOPF. The results showed that VOPF could significantly inhibit auricular swelling, intraperitoneal capillary permeability in mice, and reduce granuloma swelling and paw swelling in rats. Furthermore, it significantly alleviated the pathological damage of the lung tissue. In addition, VOPF could reduce the contents of IL-1β and TNF-α and increase the content of IL-10 in the serum. It had little effect on the expression of p65 but reduced the phosphorylation level of p65 and IκB in NF-κB pathway. In conclusion, VOPF has anti-inflammatory effects and the mechanisms involve the down-regulation of the phosphorylation levels of p65 and IκB and blockage of the NF-κB signaling pathway.

Synthesis of Colloidal CuNPs Using the Extract of Thuja Orientalis

Green synthesis as an alternative technique for bioproduction of metallic nanomaterials has presented a great interest due to the composition of reducing agents in plants, bacteria, and fungi that favor the production of nanostructured materials. In this investigation, the extract of Thuja Orientalis was used to evaluate the synthesis of copper nanoparticles. The species presents biomolecules which make it a candidate for the reduction of metal ions. The FTIR analysis showed the presence of functional groups OH, CH, C=O, COOH, -OCH3, C-O-C proper to polyphenols, terpenes, and ligands. The kinetics of CuNPs synthesis was analyzed by UV-vis in which a narrow absorbance band was shown at 400 nm after 20 minutes of reaction using a concentration of precursor agent of 50 mM, giving us indications of a homogeneous system of nanoparticles, which was corroborated by SEM obtaining a particle size between 5-60 nm with a spherical morphology. By cyclic voltammetry, the reducing power of the extract against the ions of Cu+2 to Cu0 was demonstrated, as well as its tendency to oxidation, which can have great advantages in different applications.

Quantitative Comparison of Methods to Assess the Airborne Particulate Matter Retention Capacity of Leaves

The objective of this study was to explore the differences of five methods for evaluating the PM retention capacity of leaves based on the same experimental materials and leaf area measurement method and to summarize the advantages and disadvantages of each method. In this study, four tree species (Pinus tabuliformis, Platycladus orientalis, Ginkgo biloba, and Platanus occidentalis), which are common in Beijing and have greatly different leaf characteristics, were selected as the research objects. The mass subtraction method (MS), the membrane filter method (MF), the aerosol regenerator method(AR), the scanning electron method (SEM), and the elution weighing method coupled with a particle size analysis based on ultrasonic cleaning (ultrasonic-EWPA) were used to evaluate the PM retention capabilities and characteristics of the leaves of the four tree species. The total time needed and the total cost were measured simultaneously during the evaluation process. The results showed that although the values of PM retention efficiency obtained by different methods were quite different, the ranks of the efficiency of four tree species obtained by different methods were the same or partially the same. Additionally, the results obtained by the methods with the same or similar principles were more overlapped (AR and SEM had the most overlapped results). In addition, 89% of the species ranks of the same index obtained by each method were P. orientalis > P. tabuliformis > P. occidentalis > G. biloba, and the remaining 11% were P. occidentalis > G. biloba > P. orientalis > P. tabuliformis. Among the five methods, ultrasonic-EWPA was the one with the largest number of indexes and the highest cost, and MS was the one with the least number of indexes and the lowest cost. The one that needed most time was MF, while the one that needed the least time was AR. ultrasonic-EWPA and SEM are high input and high output methods. That is to say, although they needed more time and cost, they can prove more information; however, MS was opposite, which resulted in less information but lower time and cost needed. So, it is suitable for roughly evaluating the total PM retention capacities of trees; MF had a medium amount of information, low cost, but required too much time, which needs to be weighed and balanced before selecting this method. The AR method had strict requirements for equipment and parameters and should be used with caution. The results of this study can provide a comprehensive and detailed scientific basis for researchers to choose specific methods in the future.

兰州市南山和北山3种乔木叶片生态化学计量特征的对比研究

叶片生态化学计量是了解生物地球化学循环的窗口，也是认识植物的生长状况及生态适应性的关键，研究人工林叶片生态化学计量特征对进一步优化生态工程建设具有重要意义。为揭示兰州市南北两山主要绿化树种侧柏、圆柏和云杉环境适应性的异同，对其叶片生态化学计量特征进行了对比研究。结果显示：云杉、圆柏叶片C含量（496.02、497.64 g/kg）显著高于侧柏叶片（484.12 g/kg），侧柏叶片N、P含量（17.70、1.66 g/kg）均显著高于圆柏（14.04、1.42 g/kg）和云杉（15.62、1.40 g/kg）。C、N、P的变异系数均为圆柏 < 侧柏 < 云杉；云杉、圆柏叶片C ∶ N （33.32、35.42）、C ∶ P （389.57、360.52）显著高于侧柏叶片（28.17、306.07），云杉叶片N ∶ P （11.88）显著高于圆柏叶片（10.20）和侧柏叶片（10.98）。C ∶ N、C ∶ P、N ∶ P的变异系数均为圆柏 < 侧柏 < 云杉；侧柏和云杉叶片N含量与P含量正相关、与C ∶ N、C ∶ P负相关，而3种乔木叶片P含量与C ∶ P、N ∶ P负相关（且C ∶ P与N ∶ P正相关）。圆柏叶片C含量与N含量正相关，侧柏叶片C含量与N含量负相关但与叶片C ∶ N、C ∶ P正相关，侧柏和云杉叶片C ∶ N与C ∶ P正相关。冗余分析表明，SOC ∶ STN是影响3种乔木叶片化学计量的主导因子，圆柏叶片C、侧柏叶片P与SOC正相关，3种乔木叶片N都与SOC、SOC ∶ STN和SOC ∶ STP正相关；云杉叶片N，侧柏、云杉叶片P和STP负相关，而STP与侧柏叶片C ∶ P、N ∶ P及云杉叶片C ∶ N正相关；3种乔木叶片C ∶ N与SOC ∶ STN、SOC ∶ STP负相关。研究结果表明：面对养分贫瘠的土壤环境，3种乔木叶片生态化学计量的适应策略有所不同，其中云杉和圆柏采取防御策略，而侧柏采取竞争倾向策略。虽然云杉是兰州市较适宜的造林树种，但其生长与其他两种乔木一样，都受N元素的限制。;Foliar stoichiometry is a window to understand the biogeochemical cycle, as well as understand plant growth and ecological adaptability. Studying the foliar stoichiometry of artificial forests is of great significance for further optimizing ecological projects. In order to reveal the similarities and differences of the main greening species (Sabina chinensis, platycladus orientalis, Picea asperata) to environmental adaptability in the north and south mountains of Lanzhou City, the foliar stoichiometry traits of three trees were compared. The results showed that the foliar C contents of Picea asperata and Sabina chinensis (497.64 g/kg, and 496.02 g/kg, respectively) was significantly higher than that of platycladus orientalis (484.12 g/kg). The foliar N content of platycladus orientalis (17.70 g/kg) was significantly higher than that of Sabina chinensis and Picea asperata (14.04 g/kg,15.62 g/kg, respectively), and this trend was also found for foliar P content, with the former being 1.66 g/kg, and the latter two being 1.42 g/kg and 1.40 g/kg, respectively. The order of variation coefficients of C, N, and P were Sabina chinensis < platycladus orientalis < Picea asperata. The foliar C ∶ N and C ∶ P of Sabina chinensis (35.42 and 360.52, respectively) and Picea asperata (33.32 and 389.57, respectively) were both significantly higher than the C ∶ N (28.17) and C ∶ P (306.07) of platycladus orientalis. The foliar N ∶ P (11.88) of Picea asperata was significantly higher than that of Sabina chinensis (10.20) and platycladus orientalis (10.98). The order of variation coefficients of C ∶ N, C ∶ P, and N ∶ P were Sabina chinensis < platycladus orientalis < Picea asperata. The foliar N contents of platycladus orientalis and Picea asperata were positively related to the foliar P content, but were negatively related to the foliar C ∶ N and C ∶ P. The foliar P contents of the three trees were negatively related to the foliar C ∶ P and N ∶ P, with being positive correlation with each other. The foliar C content of Sabina chinensis was positively related to the foliar N content, yet for platycladus orientalis it was negatively related to the foliar N content, but positively related to the foliar C ∶ N and C ∶ P. The redundant analysis showed that foliar stoichiometry traits were mainly influenced by soil organic carbon (SOC): soil total nitrogen (STN), with the foliar C content of Sabina chinensis being positively correlated with SOC, SOC ∶ STN, and soil pH; the foliar N content of the three trees were all positively correlated with SOC, SOC ∶ STN, and SOC ∶ STP. The foliar N content of Picea asperata, and the foliar P content of platycladus orientalis and Picea asperata were negatively correlated with soil total phosphorus (STP), while the STP was positively correlated with the foliar C ∶ P and N ∶ P of platycladus orientalis and foliar C ∶ N of Picea asperata, respectively. The foliar C ∶ N values of the three trees were negatively correlated with SOC ∶ STN and SOC ∶ STP. The results suggest that three major trees have different adaptation strategies under poor nutrient habitat, with a defensive strategy for Sabina chinensis and Picea asperata, and a competitive strategy for platycladus orientalis. Though Picea asperata may be the most suitable species that were planted in north and south mountains of Lanzhou City, the growth of the three trees were all limited by STN.

Regeneration Characteristics and Spatial Pattern of &amp;lt;i&amp;gt;Platycladus orientalis&amp;lt;/i&amp;gt; in Mount Tai, China

Platycladus orientalis is one of the main tree species in Mount Tai, and its sustainable development is of great significance to the protection and development of the forest ecological environment of Mount Tai. In this study, a representative sample plot of Platycladus orientalis with a size of 30 m * 20 m was selected on Mount Tai. The growth and distribution of the parent trees and seedlings of Platycladus orientalis were investigated in the sample plots. The results showed that both the mother cypress trees and seedlings inside the plot present an aggregated distribution pattern within a certain scale, which conforms to the distribution of most natural communities; and the mother cypress can promote seedlings within a certain scale. Although Platycladus orientalis has good natural regeneration ability, it is difficult to succeed in understory regeneration solely relying on natural fertility, and it is not conducive to the long-term stable development of forest stands. Therefore, the thinning of Platycladus orientalis and the adjustment of the forest stand structure and artificial promotion of natural regeneration can not only reduce operating costs, but also conform to the idea of forest near-natural management and maintain sustainable forest development.

Preparation and Characterization of Solid Lipid Nanoparticles Containing Total Extract and Fractions Of&nbsp; Platycladus Orientalis L

Preparation and Characterization of Solid Lipid Nanoparticles Containing Total Extract and Fractions Of&nbsp; <i>Platycladus Orientalis L</i>