Transcriptome analysis of the bloom-forming dinoflagellate Prorocentrum donghaiense exposed to Ginkgo biloba leaf extract, with an emphasis on photosynthesis.

Ginkgo biloba leaf extract (GBE) can effectively treat bloom-forming freshwater algae. However, there is limited information about the underlying suppression mechanism of the marine bloom-forming Prorocentrum donghaiense-the most dominant algal bloom species in the East China Sea. We investigated the effect of GBE on P. donghaiense in terms of its response to photosynthesis at the molecular/omic level. In total, 93,743 unigenes were annotated using six functional databases. Furthermore, 67,203 differentially expressed genes (DEGs) were identified in algae treated with 1.8 g∙L-1 GBE. Among these DEGs, we identified the genes involved in photosynthesis. PsbA, PsbB and PsbD in photosystem II, PsaA in photosystem I, and PetB and PetD in the cytochrome b6/f complex were downregulated. Other related genes, such as PsaC, PsaE, and PsaF in photosystem I; PetA in the cytochrome b6/f complex; and atpA, atpD, atpH, atpG, and atpE in the F-type H+-ATPase were upregulated. These results suggest that the structure and activity of the complexes were destroyed by GBE, thereby inhibiting the electron flow between the primary and secondary quinone electron acceptors, primary quinone electron acceptor, and oxygen-evolving complex in the PSII complex, and interrupting the electron flow between PSII and PSI, ultimately leading to a decline in algal cell photosynthesis. These findings provide a basis for understanding the molecular mechanisms underlying P. donghaiense exposure to GBE and a theoretical basis for the prevention and control of harmful algal blooms.

An unprecedented pair of Z/E isomeric pyridinium compound from the aqueous extract of Aspongopus chinensis Dallas / 药学学报

A novel pair of Z/E isomeric compounds with unprecedented carbon skeleton were isolated from an aqueous extract of Aspongopus chinensis Dallas by macroporous resin, silica gel, and semi-preparative high performance liquid chromatography (HPLC). Their structures were identified by nuclear magnetic resonance (NMR), Infrared spectroscopy (IR), Mass spectroscopy (MS) and other spectroscopic methods as (Z)-3-(but-1″-en-1″-yl)-1-(2ʹ-hydroxyethyl)-4-propylpyridin-1-ium, namely aspongopyridine A, and (E)-3-(but-1″-en-1″-yl)-1-(2ʹ-hydroxyethyl)-4-propylpyridin-1-ium, namely aspongopyridine B, respectively. Besides, the anti-inflammatory, anti-tumor, acetylcholinesterase inhibition and butyrylcholinesterase inhibition activities of the compounds 1 and 2 were evaluated. The results showed that compounds 1 and 2 have no anti-inflammatory, anti-tumor, and butyrylcholinesterase inhibition activities instead of weak acetylcholinesterase inhibition activity.

Allelopathic Inhibition and Mechanism of Quercetin on Microcystis aeruginosa.

The utilization of allelochemicals to inhibit algal overgrowth is a promising approach for controlling harmful algal blooms (HABs). Quercetin has been found to have an allelopathic effect on algae. However, its responsive mechanism needs to be better understood. In the present study, the inhibitory effects of different quercetin concentrations on M. aeruginosa were evaluated, and the inhibition mechanisms were explored. The results demonstrated that quercetin significantly inhibited M. aeruginosa growth, and the inhibitory effect was concentration-dependent. The inhibition rate of 40 mg L-1 quercetin on algal density reached 90.79% after 96 h treatment. The concentration of chlorophyll-a (chl-a) in treatment groups with quercetin concentrations of 10, 20, and 40 mg L-1 decreased by 59.74%, 74.77%, and 80.66% at 96 h, respectively. Furthermore, quercetin affects photosynthesis and damages the cell membrane, respiratory system, and enzyme system. All photosynthetic fluorescence parameters, including the maximum photochemical quantum yield (Fv/Fm), the actual photochemical quantum yield (YII), the maximum relative electron transfer rate (rETRmax), and light use efficiency (α), exhibited a downtrend after exposure. After treatment with 20 mg L-1 quercetin, the nucleic acid and protein content in the algal solution increased, and the respiration rate of algae decreased significantly. Additionally, superoxide dismutase (SOD) activities significantly increased as a response to oxidative stress. In comparison, the activities of ribulose 1,5-biphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) decreased significantly. These results revealed that quercetin could inhibit M. aeruginosa by affecting its photosynthesis, respiration, cell membrane, and enzymic system. These results are promising for controlling M. aeruginosa effectively.

Nurses' Colleague Solidarity and Job Performance: Mediating Effect of Positive Emotion and Turnover Intention

Background@#Job performance is known as an essential reflection of nursing quality. Colleague solidarity, positive emotion, and turnover intention play effective roles in a clinical working environment, but their impacts on job performance are unclear. Investigating the association between nurses’ colleague solidarity and job performance may be valuable, both directly and through the mediating roles of positive emotion and turnover intention. @*Methods@#In this cross-sectional study, a total of 324 Chinese nurses were recruited by convenience sampling method from July 2016 to January 2017. Descriptive analysis, Spearman’s correlation analysis, and the structural equation model were applied for analysis by SPSS 26.0 and AMOS 24.0. @*Results@#A total of 49.69% of participants were under 30 years old, and 90.12% of participants were female. Colleague solidarity and positive emotion were positively connected with job performance. The results indicated the mediating effects of positive emotion and turnover intention in this relationship, respectively, as well as the chain mediating effect of positive emotion and turnover intention. @*Conclusions@#In conclusion, dynamic and multiple supportive strategies are needed for nurse managers to ameliorate nursing job performance by improving colleague solidarity and positive emotion and decreasing turnover intention based on the job demand-resource model.

UPLC-MS/MS Technology for the Quantitative Methodology and Pharmacokinetic Analysis of Voxtalisib in Rat Plasma.

Voxtalisib, is a specific, effective, and reversible dual inhibitor, which inhibits both pan-class I phosphoinositide 3-kinase (PI3K) and mechanistic target of rapamycin (mTOR). To date, voxtalisib has been studied in trials for melanoma, lymphoma, glioblastoma, breast cancer, and other cancers. In this study, a highly sensitive and rapid ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) technology was applied to the quantitative methodology and pharmacokinetic analysis of voxtalisib in rat plasma. After protein precipitation of the analyte by acetonitrile, the chromatographic separation was performed by gradient elution on an Acquity BEH C18 column (2.1 mm × 50 mm, 1.7 µm) with acetonitrile (solvent A) and 0.1% formic acid (solvent B) as the mobile phase. In the positive ion mode, the mass transfer detection of the analyte and IS was m/z 270.91 > 242.98 and m/z 572.30 > 246.10, respectively. In the concentration range of 1-2000 ng/ml, a good linear relationship of voxtalisib was successfully established by the UPLC-MS/MS technology, and the lower limit of quantification (LLOQ) of the analyte was identified as 1 ng/ml. Intra-day and inter-day precisions for voxtalisib were 7.5-18.7% and 13.0-16.6%, respectively, and the accuracies were in the ranges of -14.0-2.0% and -7.2-3.1%, respectively. The matrix effect, extraction recovery, carryover and stability of the analyte were all in compliance with the acceptance criteria of bioassays recommended by FDA. Finally, the pharmacokinetic profile of the analyte had been availably studied by the UPLC-MS/MS bio-analytical method after rats were treated by intragastric administration with voxtalisib (5 mg/kg). The results indicated that the UPLC-MS/MS technology can effectively and quickly quantify the analyte, and this method can also be used for the pharmacokinetic study of voxtalisib, which can provide reference for the optimization of clinical drug management in the later period.

Effects of Ginkgo biloba extract on growth, photosynthesis, and photosynthesis-related gene expression in Microcystis flos-aquae.

The inhibitory effect of plants on algae offers a new and promising alternative method for controlling harmful algal blooms. Previous studies showed that anti-algal effects might be obvious from extracts of fallen leaves from terrestrial plants, which had great potential for cyanobacterial control in field tests. To investigate the anti-algal activities and main algicidal mechanisms of Ginkgo biloba fallen leaves extracts (GBE) on Microcystis flos-aquae, the cell density, photosynthetic fluorescence, and gene expression under different concentrations of GBE treatments were tested. GBE (3.00 g L-1) showed a strong inhibitory effect against M. flos-aquae with an IC50 (96h) of 0.79 g L-1. All the inhibition rates of maximal quantum yield (Fv/Fm), effective quantum yield (Fq'/Fm'), and maximal relative electron transfer rate (rETRmax) were more than 70% at 96 h at 3.00 g L-1 and more than 90% at 6.00 g L-1. Further results of gene expression of the core proteins of PSII (psbD), limiting enzyme in carbon assimilation (rbcL), and phycobilisome degradation protein (nblA) were downregulated after exposure. These findings emphasized that photosynthetic damage is one of the main toxic mechanisms of GBE on M. flos-aquae. When exposed to 12.00 g L-1 GBE, no significant influence on the death rate of zebrafish or photosynthetic activity of the three submerged plants was found. Therefore, appropriate use of GBE could control the expansion of M. flos-aquae colonies without potential risks to the ecological safety of aquatic environments, which means that GBE could actually be used to regulate cyanobacterial blooms in natural waters.

Determination of the ED95 of intranasal sufentanil combined with intranasal dexmedetomidine for moderate sedation during endoscopic ultrasonography.

BACKGROUND: Sedation during endoscopic ultrasonography (EUS) poses many challenges and moderate-to-deep sedation are often required. The conventional method to preform moderate-to-deep sedation is generally intravenous benzodiazepine alone or in combination with opioids. However, this combination has some limitations. Intranasal medication delivery may be an alternative to this sedation regimen. AIM: To determine, by continual reassessment method (CRM), the minimal effective dose of intranasal sufentanil (SUF) when combined with intranasal dexmedetomidine (DEX) for moderate sedation of EUS in at least 95% of patients (ED95). METHODS: Thirty patients aged 18-65 and scheduled for EUS were recruited in this study. Subjects received intranasal DEX and SUF for sedation. The dose of DEX (1 µg/kg) was fixed, while the dose of SUF was assigned sequentially to the subjects using CRM to determine ED95. The sedation status was assessed by modified observer's assessment of alertness/sedation (MOAA/S) score. The adverse events and the satisfaction scores of patients and endoscopists were recorded. RESULTS: The ED95 was intranasal 0.3 µg/kg SUF when combined with intranasal 1 µg/kg DEX, with an estimated probability of successful moderate sedation for EUS of 94.9% (95% confidence interval: 88.1%-98.9%). When combined with intranasal 1 µg/kg DEX, probabilities of successful moderate sedation at each dose level of intranasal SUF were as follows: 0 µg/kg SUF, 52.8%; 0.1 µg/kg SUF, 75.4%; 0.2 µg/kg SUF, 89.9%; 0.3 µg/kg SUF, 94.9%; 0.4 µg/kg SUF, 98.0%; 0.5 µg/kg SUF, 99.0%. CONCLUSION: The ED95 needed for moderate sedation for EUS is intranasal 0.3 µg/kg SUF when combined with intranasal 1 µg/kg DEX, based on CRM.

Commentary on "Multi-Component Care Bundle in Geriatric Fracture Hip for Reducing Postoperative Delirium".

The letter to the editor suggested several questions regarding the methodology of the recent article by Lam et al who determined effect of multicomponent care bundle on the development of postoperative delirium. This article is published in Geriatric Orthopaedic Surgery & Rehabilitation .  2021; 12:21514593211004530. Our concerns included the incomplete preoperative assessment, possible influences of anaesthetic and intraoperative managements on the development of postoperative delirium, bias effect of postoperative analgesia on the primary and secondary findings, and real clinical value of multicomponent care bundle to decrease the risk of postoperative delirium. We believe that clarifying these issues would improve the transparency of this study and interpretation of findings.