The plant ESCRT component FREE1 regulates peroxisome-mediated turnover of lipid droplets in germinating Arabidopsis seedlings.

Lipid droplets (LDs) stored during seed development are mobilized and provide essential energy and lipids to support seedling growth upon germination. Triacylglycerols (TAGs) are the main neutral lipids stored in LDs. The lipase SUGAR DEPENDENT 1 (SDP1), which hydrolyzes TAGs in Arabidopsis thaliana, is localized on peroxisomes and traffics to the LD surface through peroxisomal extension, but the underlying mechanism remains elusive. Here, we report a previously unknown function of a plant-unique endosomal sorting complex required for transport (ESCRT) component FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1) in regulating peroxisome/SDP1-mediated LD turnover in Arabidopsis. We showed that LD degradation was impaired in germinating free1 mutant; moreover, the tubulation of SDP1- or PEROXIN 11e (PEX11e)-marked peroxisomes and the migration of SDP1-positive peroxisomes to the LD surface were altered in the free1 mutant. Electron tomography analysis showed that peroxisomes failed to form tubules to engulf LDs in free1, unlike in the wild-type. FREE1 interacted directly with both PEX11e and SDP1, suggesting that these interactions may regulate peroxisomal extension and trafficking of the lipase SDP1 to LDs. Taken together, our results demonstrate a pivotal role for FREE1 in LD degradation in germinating seedlings via regulating peroxisomal tubulation and SDP1 targeting.

Phosphatidic acid modulates MPK3- and MPK6-mediated hypoxia signaling in Arabidopsis.

Phosphatidic acid (PA) is an important lipid essential for several aspects of plant development and biotic and abiotic stress responses. We previously suggested that submergence induces PA accumulation in Arabidopsis thaliana; however, the molecular mechanism underlying PA-mediated regulation of submergence-induced hypoxia signaling remains unknown. Here, we showed that in Arabidopsis, loss of the phospholipase D (PLD) proteins PLDα1 and PLDδ leads to hypersensitivity to hypoxia, but increased tolerance to submergence. This enhanced tolerance is likely due to improvement of PA-mediated membrane integrity. PA bound to the mitogen-activated protein kinase 3 (MPK3) and MPK6 in vitro and contributed to hypoxia-induced phosphorylation of MPK3 and MPK6 in vivo. Moreover, mpk3 and mpk6 mutants were more sensitive to hypoxia and submergence stress compared with wild type, and fully suppressed the submergence-tolerant phenotypes of pldα1 and pldδ mutants. MPK3 and MPK6 interacted with and phosphorylated RELATED TO AP2.12, a master transcription factor in the hypoxia signaling pathway, and modulated its activity. In addition, MPK3 and MPK6 formed a regulatory feedback loop with PLDα1 and/or PLDδ to regulate PLD stability and submergence-induced PA production. Thus, our findings demonstrate that PA modulates plant tolerance to submergence via both membrane integrity and MPK3/6-mediated hypoxia signaling in Arabidopsis.

Integrated analysis of transcriptome and small RNAome reveals regulatory network of rapid and long-term response to heat stress in Rhododendron moulmainense.

MAIN CONCLUSION: The post-transcriptional gene regulatory pathway and small RNA pathway play important roles in regulating the rapid and long-term response of Rhododendron moulmainense to high-temperature stress. The Rhododendron plays an important role in maintaining ecological balance. However, it is difficult to domesticate for use in urban ecosystems due to their strict optimum growth temperature condition, and its evolution and adaptation are little known. Here, we combined transcriptome and small RNAome to reveal the rapid response and long-term adaptability regulation strategies in Rhododendron moulmainense under high-temperature stress. The post-transcriptional gene regulatory pathway plays important roles in stress response, in which the protein folding pathway is rapidly induced at 4 h after heat stress, and alternative splicing plays an important role in regulating gene expression at 7 days after heat stress. The chloroplasts oxidative damage is the main factor inhibiting photosynthesis efficiency. Through WGCNA analysis, we identified gene association patterns and potential key regulatory genes responsible for maintaining the ROS steady-state under heat stress. Finally, we found that the sRNA synthesis pathway is induced under heat stress. Combined with small RNAome, we found that more miRNAs are significantly changed under long-term heat stress. Furthermore, MYBs might play a central role in target gene interaction network of differentially expressed miRNAs in R. moulmainense under heat stress. MYBs are closely related to ABA, consistently, ABA synthesis and signaling pathways are significantly inhibited, and the change in stomatal aperture is not obvious under heat stress. Taken together, we gained valuable insights into the transplantation and long-term conservation domestication of Rhododendron, and provide genetic resources for genetic modification and molecular breeding to improve heat resistance in Rhododendron.

Using a new human milk fortifier to optimize human milk feeding among very preterm and/or very low birth weight infants: a multicenter study in China.

BACKGROUND: Human milk fortifier (HMF) composition has been optimized recently. But clinical evidence of its safety and efficacy is limited in Chinese population. The aim of this study was to evaluate effects of a new HMF in growth, nutritional status, feeding intolerance, and major morbidities among very preterm (VPT) or very low birth weight (VLBW) infants in China. METHODS: VPT/VLBW infants admitted from March 2020 to April 2021 were prospectively included in the experimental (new HMF, nHMF) group, who received a new powdered HMF as a breast milk feeding supplement during hospitalization. Infants in the control group (cHMF) admitted from January 2018 to December 2019, were retrospective included, and matched with nHMF group infants for gestational age and birth weight. They received other kinds of commercially available HMFs. Weight gain velocity, concentrations of nutritional biomarkers, incidence of major morbidities, and measures of feeding intolerance were compared between the two groups. RESULTS: Demographic and clinical characteristics of infants in nHMF and cHMF groups were comparable. Weight gain velocity had no significant difference between the nHMF (14.0 ± 3.5 g/kg/d) and the cHMF group (14.2 ± 3.8 g/kg/d; P = 0.46). Incidence of morbidities, including necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity, culture-confirmed sepsis, and feeding intolerance during hospitalization between nHMF and cHMF, were similar (all P-values > 0.05). The time to achieve full enteral feeding [13.5 (10, 21) days] in the nHMF group was significantly shorter than that in the cHMF group [17 (12, 23) days, HR = 0.67, 95%CI: 0.49, 0.92; P = 0.01]. Compared with cHMF group, the decrease of blood urea nitrogen level over time in nHMF group was smaller (ß = 0.6, 95%CI:0.1, 1.0; P = 0.01). CONCLUSIONS: The new HMF can promote growth of preterm infants effectively without increasing the incidence of major morbidity and feeding intolerance. It can be used feasible in Chinese VPT/VLBW infants. TRIAL REGISTRATION: This study was registered on ClinicalTrials.gov (NCT04283799).

MYB30 integrates light signals with antioxidant biosynthesis to regulate plant responses during postsubmergence recovery.

Submergence is an abiotic stress that limits agricultural production world-wide. Plants sense oxygen levels during submergence and postsubmergence reoxygenation and modulate their responses. Increasing evidence suggests that completely submerged plants are often exposed to low-light stress, owing to the depth and turbidity of the surrounding water; however, how light availability affects submergence tolerance remains largely unknown. Here, we showed that Arabidopsis thaliana MYB DOMAIN PROTEIN30 (MYB30) is an important transcription factor that integrates light signaling and postsubmergence stress responses. MYB DOMAIN PROTEIN30 protein abundance decreased upon submergence and accumulated during reoxygenation. Under submergence conditions, CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1), a central regulator of light signaling, caused the ubiquitination and degradation of MYB30. In response to desubmergence, however, light-induced MYB30 interacted with MYC2, a master transcription factor involved in jasmonate signaling, and activated the expression of the VITAMIN C DEFECTIVE1 (VTC1) and GLUTATHIONE SYNTHETASE1 (GSH1) gene families to enhance antioxidant biosynthesis. Consistent with this, the myb30 knockout mutant showed increased sensitivity to submergence, which was partially rescued by overexpression of VTC1 or GSH1. Thus, our findings uncover the mechanism by which the COP1-MYB30 module integrates light signals with cellular oxidative homeostasis to coordinate plant responses to postsubmergence stress.

Arabidopsis SINAT Proteins Control Autophagy by Mediating Ubiquitylation and Degradation of ATG13.

In eukaryotes, autophagy maintains cellular homeostasis by recycling cytoplasmic components. The autophagy-related proteins (ATGs) ATG1 and ATG13 form a protein kinase complex that regulates autophagosome formation; however, mechanisms regulating ATG1 and ATG13 remain poorly understood. Here, we show that, under different nutrient conditions, the RING-type E3 ligases SEVEN IN ABSENTIA OF ARABIDOPSIS THALIANA1 (SINAT1), SINAT2, and SINAT6 control ATG1 and ATG13 stability and autophagy dynamics by modulating ATG13 ubiquitylation in Arabidopsis (Arabidopsis thaliana). During prolonged starvation and recovery, ATG1 and ATG13 were degraded through the 26S proteasome pathway. TUMOR NECROSIS FACTOR RECEPTOR ASSOCIATED FACTOR1a (TRAF1a) and TRAF1b interacted in planta with ATG13a and ATG13b and required SINAT1 and SINAT2 to ubiquitylate and degrade ATG13s in vivo. Moreover, lysines K607 and K609 of ATG13a protein contributed to K48-linked ubiquitylation and destabilization, and suppression of autophagy. Under starvation conditions, SINAT6 competitively interacted with ATG13 and induced autophagosome biogenesis. Furthermore, under starvation conditions, ATG1 promoted TRAF1a protein stability in vivo, suggesting feedback regulation of autophagy. Consistent with ATGs functioning in autophagy, the atg1a atg1b atg1c triple knockout mutants exhibited premature leaf senescence, hypersensitivity to nutrient starvation, and reduction in TRAF1a stability. Therefore, these findings demonstrate that SINAT family proteins facilitate ATG13 ubiquitylation and stability and thus regulate autophagy.

SINAT E3 Ubiquitin Ligases Mediate FREE1 and VPS23A Degradation to Modulate Abscisic Acid Signaling.

In plants, the ubiquitin-proteasome system, endosomal sorting, and autophagy are essential for protein degradation; however, their interplay remains poorly understood. Here, we show that four Arabidopsis (Arabidopsis thaliana) E3 ubiquitin ligases, SEVEN IN ABSENTIA OF ARABIDOPSIS THALIANA1 (SINAT1), SINAT2, SINAT3, and SINAT4, regulate the stabilities of FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING1 (FREE1) and VACUOLAR PROTEIN SORTING23A (VPS23A), key components of the endosomal sorting complex required for transport-I, to modulate abscisic acid (ABA) signaling. GFP-SINAT1, GFP-SINAT2, and GFP-SINAT4 primarily localized to the endosomal and autophagic vesicles. SINATs controlled FREE1 and VPS23A ubiquitination and proteasomal degradation. SINAT overexpressors showed increased ABA sensitivity, ABA-responsive gene expression, and PYRABACTIN RESISTANCE1-LIKE4 protein levels. Furthermore, the SINAT-FREE1/VPS23A proteins were codegraded by the vacuolar pathway. In particular, during recovery post-ABA exposure, SINATs formed homo- and hetero-oligomers in vivo, which were disrupted by the autophagy machinery. Taken together, our findings reveal a novel mechanism by which the proteasomal and vacuolar turnover systems regulate ABA signaling in plants.

Study on endocrine disruption effect of paclobutrazol and uniconazole on the thyroid of male and female rats based on lipidomics.

The present study investigated the effects of paclobutrazol and uniconazole on thyroid endocrine system in rats. Lipidomic analysis was performed to obtain the biomarkers of thyroid endocrine disruption induced by paclobutrazol and uniconazole. Network pharmacology was further used to discover potential targets of biomarkers related to drugs and diseases. After paclobutrazol and uniconazole administration, seven and four common biomarkers related to thyroid endocrine disruption for female and male rats were obtained, respectively. Paclobutrazol and uniconazole significantly increased the biomarker levels of PG (12:0/15:0), PS (14:0/16:0), PA (20:1/15:0) and PG (13:0/17:0) in both sexes of rats. Exposure to paclobutrazol additionally caused a significant decrease of PG (22:6/20:2), PE (24:1/18:1) and PE (24:0/18:0) in female rats, while an increase in male rats. Changes of the common biomarkers for paclobutrazol and uniconazole revealed similar endocrine disruption effect, which was higher in the females. Network pharmacology and KEGG pathway analysis indicated that the thyroid endocrine disrupting effects of paclobutrazol and uniconazole may be related to V-akt murine thymoma viral oncogene homolog (Akts), mitogen-activated protein kinase (MAPKs), epidermal growth factor receptor (EGFR), Insulin-like growth factor (IGF-1), IGF-IR and V-Raf murine sarcoma viral oncogene homolog B1 (BRAF). The results demonstrated that paclobutrazol and uniconazole could cause thyroid endocrine disorders in male and female rats, which were sex-specific, thus highlighting the importance of safe and effective application of these plant growth regulators.

Epidemiological Investigation on the Current Practice of Umbilical Cord Clamping in China.

OBJECTIVE: Despite known benefits, the timing of and method used for umbilical cord clamping (UCC) in neonates remain controversial in China, as well as internationally. The objective of this study was to assess knowledge, attitudes, and practice of UCC amongst health care providers in China, as recommended by medical professional organizations. STUDY DESIGN: A web-based questionnaire on cord clamping practices was administered to midwives, obstetricians, and neonatologists in 126 hospitals from 16 provinces. The provinces were selected from seven different regions of China. RESULTS: A total of 5,005 (60.5% of eligible respondents) health care providers returned completed questionnaires. The awareness rates for immediate cord clamping (ICC) and delayed cord clamping (DCC) were over 85%, but the implementation rate for DCC was relatively low (ICC 58.3% vs. DCC 41.6%). Most neonates were placed below the introitus (92.8%) during cord clamping and this correlated with the route of delivery. The choice of UCC was impelled by different factors. Benefits for neonates influenced the choice of ICC (50%) and promoting a larger blood volume to stabilize systemic circulation influenced the choice of DCC (92.3%). Majority (91.5%) of respondents acquiesced that it was necessary to develop national clinical guidelines for UCC. CONCLUSION: The majority of obstetricians, neonatologists, and midwives who participated in this study had a positive perception of DCC. However, this did not translate to daily practice. The practice of UCC is variable and there are no standard guidelines. KEY POINTS: · The first large-scale epidemiological investigation of umbilical cord ligation is in China.. · The survey included three commonly used umbilical cord clamping methods.. · The respondents included neonatologists..

Effects of Umbilical Cord Milking on Anemia in Preterm Infants: A Multicenter Randomized Controlled Trial.

OBJECTIVE: This study aimed to investigate whether umbilical cord milking (UCM) prevents and controls anemia in preterm infants, as compared with immediate cord clamping (ICC). STUDY DESIGN: Pregnant women delivering at <34 weeks' gestation in four hospitals were randomly assigned to undergo UCM or ICC from July 2017 to June 2019. Hematological parameters and iron status were collected and analyzed as primary outcomes at 24 hours, 1 week, 2 weeks, and 6 months after delivery. RESULTS: Neonates receiving UCM had significant higher levels of hemoglobin (Hb), hematocrit, and serum iron (p < 0.05). Lower prevalence of anemia and lower need for transfusions were noted in UCM group. Although UCM was associated with prolonged duration of phototherapy, the maximum levels of bilirubin were similar between two groups (p > 0.05). CONCLUSION: UCM is an effective intervention to help preterm infants experience less anemia with the potential to increase blood volume, as seen by higher Hb levels and more enhanced iron stores.

Enhanced biogas biological upgrading from kitchen wastewater by in-situ hydrogen supply through nano zero-valent iron corrosion.

The in-situ hydrogen supply by nano zero-valent iron (nZVI, nFe0) corrosion provided a feasible way to improve the efficiency of biogas biological upgrading. This work studied the effects of nZVI at different dosages (0, 2, 4, 6, 8 and 10 g/L) on anaerobic digestion of kitchen wastewater by two buffer systems 2-[4-(2-hydroxyethyl) piperazin-1-yl] ethanesulfonic acid (HEPES) and sodium hydrogen carbonate (NaHCO3). The addition of nZVI improved the content of methane (CH4) and stability of anaerobic digestion process. In HEPES buffer system, the CH4 was all increased and the maximum reached 90.51% with 10 g/L nZVI, higher than 32.25% compared to the control. The maximum hydrogen enrichment (HE) was 113 ppb after nZVI addition, indicating the mass transfer efficiency of hydrogen (H2) was improved. Microbial community analysis showed that the total relative abundance of Methanobacterium and Methanolinea at 10 g/L nZVI was 53.72%, which was 1.62 times of the control group. However, in the NaHCO3 buffer system with 10 g/L nZVI addition, the content of CH4 and the loosely bound extracellular polymeric substances (LB-EPS) was lower than the control. The results indicated that the addition of nZVI was feasible for biogas upgrading, and the bidirectional effect of nZVI on the promotion or inhibition of bio-methanation might be related to the buffer system of the anaerobic process.

Trust and the stock market reaction to lockdown and reopening announcements: A cross-country evidence.

We conduct a country-level analysis with a sample of 44 countries to examine whether generalised social trust has an impact on the stock market reaction to government announcements of lockdown and reopening during the COVID-19 pandemic. We first conduct an event study to measure the global stock markets' reaction to government announcements of lockdown and reopening, which is measured by each stock market's cumulative abnormal return. We then employ regression analysis to investigate the relationship between generalised social trust and the stock markets' reaction to government announcements of lockdown and reopening. The results show that government announcement of lockdown had a significant negative influence on most of the stock markets, whereas the magnitude of the stock markets' reaction to government announcement of reopening is relatively marginal, indicating a possible negative bias. Moreover, we find that generalised social trust is positively related to the stock markets' reaction to government announcement of lockdown and negatively related to the stock markets' reaction to government announcement of reopening.

Brassinosteroids Antagonize Jasmonate-Activated Plant Defense Responses through BRI1-EMS-SUPPRESSOR1 (BES1).

Brassinosteroids (BRs) and jasmonates (JAs) regulate plant growth, development, and defense responses, but how these phytohormones mediate the growth-defense tradeoff is unclear. Here, we identified the Arabidopsis (Arabidopsis thaliana) dwarf at early stages1 (dwe1) mutant, which exhibits enhanced expression of defensin genes PLANT DEFENSIN1.2a (PDF1.2a) and PDF1.2b The dwe1 mutant showed increased resistance to herbivory by beet armyworms (Spodoptera exigua) and infection by botrytis (Botrytis cinerea). DWE1 encodes ROTUNDIFOLIA3, a cytochrome P450 protein essential for BR biosynthesis. The JA-inducible transcription of PDF1.2a and PDF1.2b was significantly reduced in the BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1 (BES1) gain-of-function mutant bes1- D, which was highly susceptible to S. exigua and B. cinerea BES1 directly targeted the terminator regions of PDF1.2a/PDF1.2b and suppressed their expression. PDF1.2a overexpression diminished the enhanced susceptibility of bes1- D to B. cinerea but did not improve resistance of bes1- D to S. exigua In response to S. exigua herbivory, BES1 inhibited biosynthesis of the JA-induced insect defense-related metabolite indolic glucosinolate by interacting with transcription factors MYB DOMAIN PROTEIN34 (MYB34), MYB51, and MYB122 and suppressing expression of genes encoding CYTOCHROME P450 FAMILY79 SUBFAMILY B POLYPEPTIDE3 (CYP79B3) and UDP-GLUCOSYL TRANSFERASE 74B1 (UGT74B1). Thus, BR contributes to the growth-defense tradeoff by suppressing expression of defensin and glucosinolate biosynthesis genes.

The role of an enzymatically inactive CPAF mutant vaccination in Chlamydia muridarum genital tract infection.

Chlamydia trachomatis urogenital tract infection causes pelvic inflammatory disease and infertility, increases the risk of co-infection with HPV and HIV. Chlamydial vaccination is considered the most promising approach to prevent and control its infection. Among various chlamydial vaccine candidates, chlamydial protease-like activity factor (CPAF) have been reported to provide robust protective immunity against genital chlamydial infection in mice with reduced vaginal shedding and oviduct pathology. However, CPAF is a serine protease which has enzymatical activity to degrade a large number of substrates. In order to increase the safety of CPAF vaccine, in this study, we used a mutant CPAF that is deficient in enzymatical activity to determine whether proteolytic activity of CPAF affect its vaccine efficacy. The wild type or mutant CPAF immunization causes a significant lower chlamydial shedding from the vaginal and resolve the infection as early as day 20, compared to day 28 in adjuvant control mice. More important, reduced upper reproductive tract pathology were also observed in these two groups. The mutant or wild type CPAF immunization induced not only robust splenic IFN-γ and serum IgG2a but also sIgA secretion in the vaginal fluids. Furthermore, neutralization of chlamydia with immune sera did not provide protection against oviduct pathology. However, adoptive transfer of CD4+ splenocytes isolated from the mutant or wild type CPAF immunized mice resulted in a significant and comparable reduced oviduct pathology. Our results indicate mutant CPAF vaccination is as same efficacy as wild type, and the protection relies on CD4+ T cells, which will further promote the development of CPAF as clinical chlamydial vaccine.

Dynamic Change of Sedimental Microbial Community During Black Bloom-an In Situ Enclosure Simulation Study.

Black bloom is a worldwide environmental problem. Sediment microbes play important roles in the process of black bloom. The dynamic change of sedimental microbial community and their potential link between taste and odor compounds during black bloom was investigated in an in situ black bloom enclosure simulation experiment. Through high-throughput sequencing and analysis, pronounced shifts of sedimental microbial community were observed on the 3rd and 7th day in the black bloom group. Microbes in Cyanobacteria, Verrucomicrobia, Planctomycetes, and Actinobacteria were obviously increased, while microbes from the phyla OP8, Chloroflexi, and Acidobacteria were decreased significantly. RDA analysis revealed that the concentrations of chlorophyll a (Chla), total phosphorus (TP), and turbidity (NTU) in the water and the TP, TN concentrations in the sediment were the main environmental factors that affect the microbial community in the sediment. Correlation analysis revealed that microbes Dechloromonas sp. (OTU003567 and OTU000093), Desulfococcus sp. (OTU000911), Chromatiaceae (OTU001222), and Methanosaeta sp. (OTU004809) were positively correlated with the taste and odor substances in the sediment, such as dimethyl sulfide (DMS), ß-ionone, ß-cyclocitral and geosmin. The sedimental microbial community gradually recovered in the late phase of black bloom, indicating the stability and self-recovery ability of the sedimental microbial community during black bloom. Noteworthily, we observed many possible pathogens increased significantly during the black bloom, which alerts us to keep away from contaminated sediment when black bloom occurred.

miR-381-3p suppresses breast cancer progression by inhibition of epithelial-mesenchymal transition.

BACKGROUND: Accumulating evidence indicates that miRNAs are involved in multiple cellular functions and participate in various cancer development and progression, including breast cancer. METHODS: We aimed to investigate the role of miR-381-3p in breast cancer. The expression level of miR-381-3p and EMT transcription factors was examined by quantitative real-time PCR (qRT-PCR). The effects of miR-381-3p on breast cancer proliferation and invasion were determined by Cell Counting Kit-8 (CCK-8), colony formation, and transwell assays. The regulation of miR-381-3p on its targets was determined by dual-luciferase analysis, qRT-PCR, and western blot. RESULTS: We found that the expression of miR-381-3p was significantly decreased in breast cancer tissues and cell lines. Overexpression of miR-381-3p inhibited breast cancer proliferation and invasion, whereas knockdown of miR-381-3p promoted cell proliferation and invasion in MDA-MB-231 and SKBR3 cells. Mechanistically, overexpression of miR-381-3p inhibited breast cancer epithelial-mesenchymal transition (EMT). Both Sox4 and Twist1 were confirmed as targets of miR-381-3p. Moreover, transforming growth factor-ß (TGF-ß) could reverse the effects of miR-381-3p on breast cancer progression. CONCLUSIONS: Our observation suggests that miR-381-3p inhibits breast cancer progression and EMT by regulating the TGF-ß signaling via targeting Sox4 and Twist1.

Rapid classification and identification of chemical constituents in Epimedium koreanum Nakai by UPLC-Q-TOF-MS combined with data post-processing techniques.

INTRODUCTION: Epimedium koreanum Nakai (EKN), is a well-known Chinese herbal medicine for the treatment of osteoporosis, immunosuppression, tumours and cardiovascular diseases. Comprehensive component identification is essential for elucidation of its pharmacological mechanism and quality control. However, its complex chemical composition has caused certain difficulties in the analysis of this traditional Chinese medicine (TCM). Therefore, there is an urgent need to establish a method for rapid classification and identification of EKN chemical components. OBJECTIVE: To establish a method for rapid classification and identification of the main components of flavonoids, organic acids and alkaloids in EKN. METHODS: The samples were analysed by ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and data post-processing techniques. The UPLC system used a BEH C18 column to separate the total extract of EKN. The mobile phase consisted of 0.1% formic acid in water and acetonitrile, and the EKN extract was analysed by gradient elution at a flow rate of 0.4 mL/min. In both the positive and negative ion modes, the fragment information was obtained and compared with those of the characteristic fragmentations and neutral losses described in the literature to quickly identify the target compounds. RESULTS: Finally, we successfully screened out 51 chemical components, including 40 flavonoids, nine organic acids, and two alkaloids. CONCLUSION: The established method not only comprehensively analysed the chemical compositions of EKN, solved the difficult problems of analysis and identification of the complex chemical compositions of the TCM, but also further promoted the development of the application of chemical compositions of TCM.

Techniques and Strategies for Potential Protein Target Discovery and Active Pharmaceutical Molecule Screening in a Pandemic.

Viruses remain a major challenge in the fierce fight against diseases. There have been many pandemics caused by various viruses throughout the world over the years. Recently, the global outbreak of COVID-19 has had a catastrophic impact on human health and the world economy. Antiviral drug treatment has become another essential means to overcome pandemics in addition to vaccine development. How to quickly find effective drugs that can control the development of a pandemic is a hot issue that still needs to be resolved in medical research today. To accelerate the development of drugs, it is necessary to target the key target proteins in the development of the pandemic, screen active molecules, and develop reliable methods for the identification and characterization of target proteins based on the active ingredients of drugs. This article discusses key target proteins and their biological mechanisms in the progression of COVID-19 and other major epidemics. We propose a model based on these foundations, which includes identifying potential core targets, screening potential active molecules of core targets, and verifying active molecules. This article summarizes the related innovative technologies and methods. We hope to provide a reference for the screening of drugs related to pandemics and the development of new drugs.

PacBio single-molecule long-read sequencing shed new light on the transcripts and splice isoforms of the perennial ryegrass.

Perennial ryegrass (Lolium perenne), one of the most widely used forage and cool-season turfgrass worldwide, has a breeding history of more than 100 years. However, the current draft genome annotation and transcriptome characterization are incomplete mainly because of the enormous difficulty in obtaining full-length transcripts. To explore the complete structure of the mRNA and improve the current draft genome, we performed PacBio single-molecule long-read sequencing for full-length transcriptome sequencing in perennial ryegrass. We generated 29,175 high-confidence non-redundant transcripts from 15,893 genetic loci, among which more than 66.88% of transcripts and 24.99% of genetic loci were not previously annotated in the current reference genome. The re-annotated 18,327 transcripts enriched the reference transcriptome. Particularly, 6709 alternative splicing events and 23,789 alternative polyadenylation sites were detected, providing a comprehensive landscape of the post-transcriptional regulation network. Furthermore, we identified 218 long non-coding RNAs and 478 fusion genes. Finally, the transcriptional regulation mechanism of perennial ryegrass in response to drought stress based on the newly updated reference transcriptome sequences was explored, providing new information on the underlying transcriptional regulation network. Taken together, we analyzed the full-length transcriptome of perennial ryegrass by PacBio single-molecule long-read sequencing. These results improve our understanding of the perennial ryegrass transcriptomes and refined the annotation of the reference genome.

Rapid analysis of a doxycycline hydrochloride solution by metallic mesh device-based reflection terahertz spectroscopy.

Terahertz (THz) spectroscopy has the advantages of non-ionization and spectroscopic fingerprint, which can be used for biological and chemical compound analysis. However, because of the strong absorption of water in the THz region, it is still a challenge for THz waves to realize aqueous solution detection. In this study, taking a doxycycline hydrochloride (DCH) aqueous solution as the target, we proposed a THz metallic mesh device (MMD) based reflection platform for the first time for sensing. The angle characteristics of the THz MMD was investigated through numerical simulations and experimental measurements to get an optimized configuration for the platform. When the projection of THz electric field polarization onto the MMD plane gets parallel to latitudinal direction of the MMD apertures, a strong resonant surface mode can be achieved, and our proposed platform can be successfully used to detect the DCH solution with a concentration as low as 1 mg L-1. The sensing mechanism of our platform was also explored by analyzing the influences of the immersion depth into the MMD holes and the extinction coefficient of droplets on the reflection spectra. Our work presents a rapid, low-cost, and practical platform for antibiotic solution sensing using THz radiation, which opens new avenues for the microanalysis of chemicals or biomolecules in strongly absorptive solutions in the THz region.