The Composition and Diversity of the Rhizosphere Bacterial Community of Ammodendron bifolium Growing in the Takeermohuer Desert Are Different from Those in the Nonrhizosphere.

Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing (i.e., stabilizing sand dunes) and endangered plant in the Takeermohuer Desert, and the bacterial community associated with this plant rhizosphere is still unclear. In this study, we investigated the composition and diversity of the bacterial community from the A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using culture and high-throughput sequencing methods. We preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. The results showed that the high-salinity Takeermohuer Desert has an oligotrophic environment, while the A. bifolium rhizosphere exhibited a relatively nutrient-rich environment due to higher contents of soil organic matter (SOM) and soil alkaline nitrogen (SAN) than bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phylum level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in the rhizosphere, and those of Firmicutes (9.8%) and Chloroflexi (6.9%) were relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genera were Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD_whole_tree indices in the rhizosphere soil were significantly higher than those in the bulk soil at the same soil depth and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in the Takeermohuer Desert were the phyla Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi. Furthermore, the major edaphic factors affecting the rhizosphere bacterial community were electrical conductivity (EC), SOM, soil total nitrogen (STN), SAN, and soil available potassium (SAK), while the major edaphic factors affecting the bacterial community in bulk soil were distance and ratio of carbon to nitrogen (C/N). We concluded that the A. bifolium rhizosphere bacterial community is different from that of the nonrhizosphere in composition, structure, diversity, and driving factors, which may improve our understanding of the relationship between plant and bacterial communities and lay a theoretical foundation for A. bifolium species conservation in desert ecosystems.

Composition and Distribution Characteristics of Rhizosphere Bacterial Community of Ammodendron bifolium Growing in Takeermohuer Desert Are Different from Those in Non-rhizosphere.

Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing and endangered plant in Takeermohuer Desert, and bacterial community associated with this plant rhizosphere is still unclear. In this study, we studied the composition and diversity of bacterial community from A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using traditional bacterial isolation and high-throughput sequencing approaches, and preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. Results showed that Takeermohuer Desert with high salinity has been an oligotrophic environment, while the rhizosphere exhibited eutrophication resulting from high content SOM (soil organic matter) and SAN (soil alkaline nitrogen) compared with bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phyla level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in eutrophic rhizosphere, and Firmicutes (9.8%) and Chloroflexi (6.9%) relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genus was Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD indexes in rhizosphere were significantly higher than those in bulk soil at the same soil depth, and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in Takeermohuer Desert were Actinobacteria, Acidobacteria, Proteobacteria, and Chlorofexi. Furthermore, the major environmental factors affecting rhizosphere bacterial community were EC (electrical conductivity), SOM, STN (soil total nitrogen), SAN, and SAK (soil available potassium), while bulk soil were distance and C/N (STC/STN). We concluded that A. bifolium rhizosphere bacterial community is different from non-rhizosphere in composition, distribution, and environmental influencing factors, which will have important significances for understanding their ecological functions and maintaining biodiversity.

Providing targeted psychological support to frontline nurses involved in the management of COVID-19: An action research.

AIM: To develop and implement a targeted psychological support scheme for frontline nurses involved in the management of coronavirus disease 2019 (COVID-19). BACKGROUND: Nurses play a vital role in managing the ongoing COVID-19 pandemic, while confronting enormous challenges and psychological problems. METHODS: Action research design was adopted to develop and provide a targeted psychological support scheme to 1,496 frontline nurses. Data regarding nurses' feedback were collected from WeChat group chat, letters and comments on theme lectures. Subsequently, qualitative content analysis was conducted using MAXQDA. RESULTS: A targeted psychological support scheme was formed via three action cycles according to nurses' needs. Frontline nurses received psychological assistance from a research team, which offered (1) a sense of belonging, (2) a sense of professional value and pride, and (3) a sense of being protected and confident. CONCLUSION: The researchers successfully provided targeted psychological support to nurses, and nurses were motivated and became more confident when their needs were addressed. IMPLICATIONS FOR NURSING MANAGEMENT: Nurses have various types of psychological needs, which could be addressed by targeted support. It is suggested that nurse managers should identify nurses' needs in real time and provide appropriate support through multidisciplinary collaboration to improve their confidence and enhance their resilience.

WS0701: a novel sedative-hypnotic agent acting on the adenosine system.

To characterize the sedative and hypnotic profile of the novel adenosine derivative ((3S,4R,5R)-3,4-dihydroxy-5-(6-((4-hydroxy-3-methoxybenzyl)amino)-9H-purin-9-yl)tetrahydrofuran-2-yl) methyl diaconate (WS0701), we performed a variety of behavioural tests and investigated the influence of WS0701 on various sleep stages. In mice, WS0701 significantly increased the number of entries and time spent in open arms in the elevated plus maze test, indicating an anxiolytic effect. WS0701 decreased locomotor activity counts and head dips in the hole-board test and enhanced sodium pentobarbital-induced hypnosis. However, WS0701 did not induce the loss of the righting reflex or amnesic effects in behavioural models. In rats, WS0701 exerted a sedative effect and markedly prolonged the time spent in non-rapid-eye-movement sleep, especially slow-wave sleep, but reduced the time spent in rapid-eye-movement sleep (REMS). Pretreatment with the selective adenosine A2a receptor antagonist SCH58261 attenuated the sedative and hypnotic effects of WS0701. WS0701 did not protect mice against picrotoxin-induced seizures, but inhibited adenosine deaminase activity and increased adenosine levels in the frontal cortex and hypothalamus of mice. In conclusion, WS0701 shows anxiolytic, sedative as well as sleep stage alterative effects, which may be related to the adenosine system.

Protective effects of the novel adenosine derivative WS0701 in a mouse model of posttraumatic stress disorder.

AIM: To investigate the effects of the novel N6-substituted adenosine derivative {(2R,3S,4R,5R)-3,4-dihydroxy-5-[6-[(4-hydroxy-3-methoxybenzyl)amino]-9H-purin-9-yl]tetrahydrofuran-2-yl} methyl decanoate (WS0701) on stress-induced excessive fear, anxiety, and cognitive deficits in a mouse model of posttraumatic stress disorder (PTSD). METHODS: Male mice underwent a conditioned foot shock and single prolonged stress procedure to induce PTSD. Contextual/cued fear, elevated plus-maze, open field and novel object recognition tests were conduced to assess PTSD-like behaviors. From d 1, the mice were orally administered WS0701 (7.5, 15, or 30 mg·kg(-1)·d(-1)) or paroxetine (10 mg·kg(-1)·d(-1)) for two weeks. Apoptosis of hippocampal neurons was detected using flow cytometry and TUNEL staining, and expression of Bcl-2 and Bax in the hippocampus was measured with Western boltting and qPCR assays. RESULTS: WS0701 administration significantly alleviated fear, anxious behaviors and memory deficits in the mouse model of PTSD. Furthermore, WS0701 administration significantly reduced the stress-induced apoptosis of hippocampal neurons, and increased the Bcl-2/Bax ratio in the hippocampus. The positive control drug paroxetine exerted similar effects on PTSD-like behaviors and hippocampal neuron apoptosis in the mouse model of PTSD, which were comparable to those caused by the high dose of WS0701. CONCLUSION: WS0701 effectively mitigates stress-induced PTSD-like behaviors in mice, partly via inhibition of neuronal apoptosis in the hippocampus.

[Absorption dynamic characteristics of clopidogrel bisulfate polymorphs in rat].

Four crystalline forms of clopidogrel bisulfate were characterized by analytical techniques. Aiming to research the absorption characteristics of clopidogrel bisulfate polymorphs after taken orally by rat, and to estimate the influence of crystal form to pharmacodynamic action, four crystalline forms of clopidogrel bisulfate were administered intragastrically to rats, and high performance liquid chromatography (HPLC) was used to measure the contents of clopidogrel bisulfate and its metabolite in rat plasma. The metabolite of clopidogrel bisulfate was detected in rat plasma. There were significant deviations among four crystalline forms in the areas under curve of the metabolite of clopidogrel bisulfate. We concluded that the different crystal forms of clopidogrel bisulfate showed different pharmacokinetic characteristics, which might affect pharmacodynamic action.

The isolation of 1,2,3,4,6-penta-O-galloyl-beta-D-glucose from Acer truncatum Bunge by high-speed counter-current chromatography.

High-speed counter-current chromatography (HSCCC) was successfully used for the isolation and purification of 1,2,3,4,6-penta-O-galloyl-beta-D-glucose from the ethyl acetate extract of the leaves of Acer truncatum Bunge using a two-phase system composed of n-hexane-ethyl acetate-methanol-water at a volume ratio of (0.25:5:1:5, v/v/v/v) for the first time. Each injection of 80 mg crude extract yielded 7.25 mg of pure 1,2,3,4,6-penta-O-galloyl-beta-D-glucose. High-performance liquid chromatography (HPLC) analyses of the CCC fraction revealed that the purity of 1,2,3,4,6-penta-O-galloyl-beta-D- glucose was over 95%.

Pinocembrin improves cognition and protects the neurovascular unit in Alzheimer related deficits.

Amyloid-ß (Aß) peptides accumulate in the brain and initiate a cascade of pathologic events in Alzheimer's disease. The receptor for advanced glycation end products (RAGE) has been implicated to mediate Aß-induced perturbations in the neurovascular unit (NVU). We demonstrated that pinocembrin exhibits neuroprotection through inhibition of the Aß and/or RAGE pathway, but the therapeutic role and mechanism involved are not ascertained. Here, we report that a 3-month treatment with pinocembrin prevents the cognition decline in APP/PS1 transgenic mice without altering Aß burden and oxidative stress. Instead, pinocembrin is effective in conferring neurovascular protection through maintenance of neuropil ultrastructure, reduction of glial activation and levels of inflammatory mediators, preservation of microvascular function, improving the cholinergic system by conserving the ERK-CREB-BDNF pathway, and modulation of RAGE-mediated transduction. Furthermore, in an in vitro model, pinocembrin provides the NVU protection against fibrillar Aß1₋42, accompanied by regulation of neurovascular RAGE pathways. Our findings indicate that pinocembrin improves cognition, at least in part, attributable to the NVU protection, and highlights pinocembrin as a potential therapeutic strategy for the prevention and/or treatment of Alzheimer's disease.

In silico target fishing for the potential targets and molecular mechanisms of baicalein as an antiparkinsonian agent: discovery of the protective effects on NMDA receptor-mediated neurotoxicity.

The flavonoid baicalein has been proven effective in animal models of parkinson's disease; however, the potential biological targets and molecular mechanisms underlying the antiparkinsonian action of baicalein have not been fully clarified. In the present study, the potential targets of baicalein were predicted by in silico target fishing approaches including database mining, molecular docking, structure-based pharmacophore searching, and chemical similarity searching. A consensus scoring formula has been developed and validated to objectively rank the targets. The top two ranked targets catechol-O-methyltransferase (COMT) and monoamine oxidase B (MAO-B) have been proposed as targets of baicalein by literatures. The third-ranked one (N-methyl-d-aspartic acid receptor, NMDAR) with relatively low consensus score was further experimentally tested. Although our results suggested that baicalein significantly attenuated NMDA-induced neurotoxicity including cell death, intracellular nitric oxide (NO) and reactive oxygen species (ROS) generation, extracellular NO reduction in human SH-SY5Y neuroblastoma cells, baicalein exhibited no inhibitory effect on [(3) H]MK-801 binding study, indicating that NMDAR might not be the target of baicalein. In conclusion, the results indicate that in silico target fishing is an effective method for drug target discovery, and the protective role of baicalein against NMDA-induced neurotoxicity supports our previous research that baicalein possesses antiparkinsonian activity.

Quercetin protects against the Aß(25-35)-induced amnesic injury: involvement of inactivation of rage-mediated pathway and conservation of the NVU.

Quercetin has demonstrated protective effects against Aß-induced toxicity on both neurons and endothelial cells. However, whether or not quercetin has an effect on the neurovascular coupling is unclear. In the present study, we aim to investigate the anti-amnesic effects of quercetin and to explore the underlying mechanisms. Aß(25-35) (10 nmol) was administrated to mice i.c.v. Quercetin was administrated orally for 8 days after injection. Learning and memory behaviors were evaluated by measuring spontaneous alternation in Morris Water Maze test and the step-through positive avoidance test. The regional cerebral blood flow was monitored before the Aß(25-35) injection and on seven consecutive days after injection. Mice were sacrificed and cerebral cortices were isolated on the last day. The effects of quercetin on the neurovascular unit (NVU) integrity, microvascular function and cholinergic neuronal changes, and the modification of signaling pathways were tested. Our results demonstrate that quercetin treatment for Aß(25-35)-induced amnesic mice improved the learning and memory capabilities and conferred robust neurovascular coupling protection, involving maintenance of the NVU integrity, reduction of neurovascular oxidation, modulation of microvascular function, improvement of cholinergic system, and regulation of neurovascular RAGE signaling pathway and ERK/CREB/BDNF pathway. In conclusion, in Aß(25-35)-induced amnesic mice, optimal doses of quercetin administration were beneficial. Quercetin protected the NVU likely through reduction of oxidative damage, inactivation of RAGE-mediated pathway and preservation of cholinergic neurons, offering an alternative medication for Alzheimer's disease.