Two-dimensional overdamped fluctuations of the soft perovskite lattice in CsPbBr3

Lead halide perovskites exhibit structural instabilities and large atomic fluctuations thought to impact their optical and thermal properties, yet detailed structural and temporal correlations of their atomic motions remain poorly understood. Here, these correlations are resolved in CsPbBr₃ crystals using momentum-resolved neutron and X-ray scattering measurements as a function of temperature, complemented with first-principles simulations. We uncover a striking network of diffuse scattering rods, arising from the liquid-like damping of low-energy Br-dominated phonons, reproduced in our simulations of the anharmonic phonon self-energy. These overdamped modes cover a continuum of wave vectors along the edges of the cubic Brillouin zone, corresponding to two-dimensional sheets of correlated rotations in real space, and could represent precursors to proposed two-dimensional polarons. Further, these motions directly impact the electronic gap edge states, linking soft anharmonic lattice dynamics and optoelectronic properties. These results provide insights into the highly unusual atomic dynamics of halide perovskites, relevant to further optimization of their optical and thermal properties.

POS0136 ROLES OF AUTOPHAGY IN THE PATHOGENESIS OF PRIMARY GOUTY ARTHRITIS

Background:

Gout is a chronic autoinflammatory disease caused by monosodium urate (MSU) crystal deposition [1].Acute gout is characterized by an acute inflammatory reaction that resolves spontaneously within a few days[2], which is one of the distinguishing features of gout compared to other arthropathies or self-inflammatory diseases. Autophagy is a lysosomal degradation pathway that is essential for cellular growth, survival, differentiation, development and homeostasis [3]. Studies have demonstrated that autophagy might play a key role in the pathogenesis of primary gouty arthritis (GA) [4-7]. However, the roles of autophagy in the development of gout have not yet been elucidated.

Objectives:

The aim of our study was to investigate the changes in autophagy-related gene (ATG) mRNA and protein in patients and the clinical importance of these genes in primary gouty arthritis (GA) and to explore the roles of autophagy in the pathogenesis of GA.

Methods:

The mRNA and protein expression levels of ATGs (ATG3, ATG7, ATG10, ATG5, ATG12, ATG16L1, ATG4B and LC3-2) were measured in peripheral blood mononuclear cells (PBMCs) from 196 subjects, including 57 acute gout patients (AG group), 57 intercritical gout patients (IG group) and 82 healthy control subjects (HC group). The relationship between ATG expression levels and laboratory features was analyzed in GA patients.

Results:

The expression levels of ATG4B, ATG5, ATG12, ATG16L1, ATG10 and LC3-2 mRNA were much lower in the AG group than in the IG and HC groups (p<0.05), while the ATG7 mRNA level was much higher in the AG group than in the IG and HC groups (p<0.05). The protein expression levels of LC3-2, ATG3, ATG7 and ATG10 were much higher in the AG group than in the other groups, while those of ATG5, ATG12, ATG16L1 and ATG4B were far lower in the AG group than in the other groups (p<0.05). In GA patients, the levels of ATG mRNA and protein correlated with laboratory inflammatory and metabolic indexes.

Conclusion:

Altered ATG expression suggests that autophagy is involved in the pathogenesis of GA and participates in regulating inflammation and metabolism.

References:

[1]Dalbeth N, Choi HK, Joosten LAB, Khanna PP, Matsuo H, Perez-Ruiz F, et al. Gout. Nat Rev Dis Primers. 2019;5: 69.doi:10.1038/s41572-019-0115-y.

[2]Schauer C, Janko C, Munoz LE, Zhao Y, Kienhöfer D, Frey B, et al. Aggregated neutrophil extracellular traps limit inflammation by degrading cytokines and chemokines. Nat Med. 2014;20: 511-517.doi:10.1038/nm.3547.

[3]Han Y, Zhang L, Xing Y, Zhang L, Chen X, Tang P, et al. Autophagy relieves the function inhibition and apoptosis-promoting effects on osteoblast induced by glucocorticoid. Int J Mol Med. 2018;41: 800-808. doi:10.3892/ijmm.2017.3270.

[4]Yang QB, He YL, Zhong XW, Xie WG, Zhou JG. Resveratrol ameliorates gouty inflammation via upregulation of sirtuin 1 to promote autophagy in gout patients. Inflammopharmacology. 2019;27: 47-56.doi:10.1007/s10787-018-00555-4.

[5]Mitroulis I, Kambas K, Chrysanthopoulou A, Skendros P, Apostolidou E, Kourtzelis I, et al. Neutrophil extracellular trap formation is associated with IL-1β and autophagy-related signaling in gout. PLoS One. 2011;6: e29318.doi: 10.1371/journal.pone.0029318.

[6]Crişan TO, Cleophas MCP, Novakovic B, Erler K, van de Veerdonk FL, Stunnenberg HG, et al. Uric acid priming in human monocytes is driven by the AKT-PRAS40 autophagy pathway. Proc Natl Acad Sci U S A. 2017;114: 5485-5490.doi:10.1073/pnas.1620910114.

[7]Lee SS, Lee SW, Oh DH, Kim HS, Chae SC, Kim SK. Genetic analysis for rs2241880(T > C) in ATG16L1 polymorphism for the susceptibility of Gout. J Clin Rheumatol. 2019;25: e113-e115.doi:10.1097/rhu.0000000000000685.

Disclosure of Interests:

Yu-Qin Huang: None declared, Quan-Bo Zhang Grant/research support from: National Natural Science Foundation of China(General Program) (no.81974250) and Science and Technology Plan Project of Sichuan Province (no.2018JY0257), Jian-Xiong Zheng: None declared, gui-lin jian: None declared, tao-hong liu: None declared, Xin He: None declared, fan-ni xiao: None declared, qin xiong: None declared, Yu-Feng Qing Grant/research support from: Science and Technology Project of Nanchong City (no.18SXHZ0522)

Responses of growth, photosynthesis and related physiological characteristics in leaves of Acer ginnala Maxim. to increasing air temperature and/or elevated O3

Regional warming and atmospheric ozone (O₃ ) pollution are two of the most important environmental issues, and commonly coexist in many areas. Both factors have an intense impact on plants. However, little information is available on the combined and interactive effects of air warming and elevated O₃ concentrations on physiological characteristics of plants. To explore this issue, we studied variations in growth, photosynthesis and physiological characteristics of leaves of Acer ginnala seedlings exposed to control (ambient temperature and O₃ ), increasing air temperature (ambient temperature + 2 °C), elevated O₃ (ambient O₃ concentration + 40 ppb) and a combination of the two abiotic factors at different phenological stages by using open-top chambers. The results showed that increasing air temperature had no significant effect on growth, but increased photosynthesis and antioxidant enzyme activity at the leaf unfolding and defoliation stages. In contrast, elevated O₃ decreased growth and photosynthesis and caused oxidative stress injury in A. ginnala leaves at each phenological stage. The combination of increasing air temperature and elevated O3 improved growth and net photosynthetic rates of tested plants and alleviated the oxidative stress compared to O₃ alone. Our findings demonstrated that moderate warming was beneficial to A. ginnala at leaf unfolding and defoliation stages, and alleviated the adverse effects of O₃ stress on growth, photosynthesis and the antioxidant system. These results will provide a theoretical reference and scientific basis for the adaptation and response of A. ginnala under regional air warming and atmospheric O₃ pollution.

[Sleep-disordered breathing in patients with chronic heart failure before and after heart transplantation]

Objective: To explore the characteristics of sleep-disordered breathing (SDB) in chronic heart failure patients waiting for heart transplantation and the changes of SDB after transplantation. Methods: From September 2018 to December 2019, 34 patients with chronic heart failure were prospectively enrolled into this study, who were hospitalized for waiting for heart transplantation in the departments of cardiovascular medicine and cardiovascular surgery, Renmin Hospital of Wuhan University. All of them received portable sleep physiological monitoring. The characteristics of their SDB were analyzed before and after heart transplantation. Results: Of the 34 patients waiting for heart transplantation, 22 had central sleep apnea, 4 had obstructive sleep apnea and 8 had no SDB. The cycle length of Cheyne-Stokes respiration was negatively correlated with left ventricular ejection fraction. After heart transplantation, 15 patients received repeat sleep physiological monitoring and their results showed that the SDB was significantly improved, with the elimination of Cheyne-Stokes respiration. Conclusions: Patients waiting for heart transplantation had a high prevalence of SDB, with Cheyne-Stokes respiration with central sleep apnea as the main type. However, heart transplantation may eliminate the Cheyne-Stokes respiration in patients with chronic heart failure.

Medical ozone induces proliferation and migration inhibition through ROS accumulation and PI3K/AKT/NF-κB suppression in human liver cancer cells in vitro

BACKGROUND

Hepatocellular carcinoma is one of the most common malignancies and leading cancer-associated deaths worldwide. Ozone has been proposed as a promising therapeutic agent in the treatment of various disorders.

PURPOSE

The purpose of this paper is to assess the potential anticancer effects of the ozone on liver cancer cells.

METHOD

The liver cancer cell line of bel7402 and SMMC7721 was used in this study. Proliferation was evaluated using the CCK-8 and the colony formation assay. Wond healing assay and transwell assay without Matrigel were used to evaluate their migration ability. Flow cytometry was used for cell cycle analysis and reactive oxygen species (ROS) determination. Glutathione detection kit was used for measurement of glutathione level. Protein expression was estimated by western blot analysis.

RESULTS

Ozone treatment inhibited liver cancer cell proliferation, colony formation. Ozone induced G2/M phase cell cycle arrest, which could be elucidated by the change of protein levels of p53, p21, Cyclin D1, cyclin B1, cdc2, and CDK4. We also found that ozone treatment inhibited migration ability by inhibiting EMT-relating protein. Ozone also induced ROS accumulation and decreased glutathione level decreased, which contributed to the inactivation of the PI3K/AKT/NF-κB pathway. Finally, we found that pre-treatment of liver cancer cells with N-acetylcysteine resisted ozone-induced effects.

CONCLUSIONS

Ozone restrains the proliferation and migration potential and EMT process of liver cancer cells via ROS accumulation and PI3K/AKT/NF-κB suppression.

[The roles of two HIV self-testing models in promoting HIV-testing among men who have sex with men]

Objective: To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM). Methods: This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale. Results: The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant (χ² test, all P<0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing (P<0.05). Conclusions: Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

The gene NtMYC2a acts as a 'master switch' in the regulation of JA-induced nicotine accumulation in tobacco

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.

Isolation, identification and characterization of phenolic acid-degrading bacteria from soil

AIMS

To isolate, identify and characterize phenolic acid-degrading bacteria and reduce plant growth inhibition caused by phenolic acids.

METHODS AND RESULTS

A total of 11 bacterial isolates with high phthalic acid (PA)-degrading ability were obtained using mineral salt medium (MSM) medium containing PA as sole carbon source. These isolates were identified as Arthrobacter globiformis, Pseudomonas putida and Pseudomonas hunanensis by sequence analyses of the 16S rRNA gene. Among them, five Pseudomonas strains could also effectively degrade ferulic acid (FA), p-hydroxybenzoic acid (PHBA) and syringic acid (SA) in MSM solution. P. putida strain 7 and P. hunanensis strain 10 showed highly efficient degradation of PA, SA, FA and PHBA, and could reduce their inhibition of lily, watermelon, poplar and strawberry seedling growth in soils respectively. These two strains could promote plant growth in soil with phenolic acids.

CONCLUSIONS

In this study, bacterial strains with highly efficient phenolic acid-degrading abilities could not only effectively reduce the autotoxicity of phenolic acids on plants but also were able to promote plant growth in soil with phenolic acids.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, Pseudomonas can promote plant growth while degrading phenolic acids. Our results provide new choices for the biological removal of autotoxins.

Yeast cell wall product enhanced intestinal IgA response and changed cecum microflora species after oral vaccination in chickens

The study was designed to explore the effect of a commercial yeast cell wall product (YP) on chicken intestinal IgA response and cecum microbiome after oral vaccination. Chickens were fed with YP during the experiments and orally immunized with live Newcastle disease virus (NDV) vaccine at 2 wk of age. Then, the animals were sacrificed, and samples were collected to measure the indicators of hemagglutination inhibition (HI), IgA response, IgA + cells, and cecum microbiome populations. The results showed that supplement of YP significantly enhanced serum NDV HI titer, intestinal NDV-specific secretory IgA, and intestinal IgA + cells. The sequencing results revealed that obviously increased relative abundance of Ruminococcaceae and decreased population of Bacteroidaceae in cecum were found in YP group. In summary, YP supplementation in diet enhanced intestinal IgA response to NDV vaccination by oral route and modulated the cecum microbiota to the advantage of the host in chickens.

Molecular-Weight Growth in Ozone-Initiated Low-Temperature Oxidation of Methyl Crotonate

We report experiments of ozone-initiated low-temperature oxidation of methyl crotonate (MC, CH₃-CH═CH-C(O)OCH₃) from 420 to 660 K in a near-atmospheric-pressure jet-stirred reactor using photoionization molecular-beam mass spectrometry as a sampling technique. In this temperature regime, no typical low-temperature combustion (LTC) reactions have been observed for MC when oxygen (O₂) is used as the oxidizer. Upon ozone addition, significant oxidation of methyl crotonate is found. On the basis of experimentally observed energy-dependent mass peaks in combination with temperature-dependent mole fraction profiles and photoionization efficiency curves, we provide new insights into the methyl crotonate ozonolysis reaction network. The observed MC + O₃ products, C₅H₈O₅, are found to be related to the keto-hydroperoxides resulting from the isomerization of the primary ozonide. Evidence is also provided that molecular growth mainly results from cycloaddition reactions of the Criegee intermediate into aldehydes and alkenes as well as addition reactions of the Criegee intermediates to the double bond of methyl crotonate and sequential decomposition into ketones. Furthermore, species that contribute in large amounts to the low-temperature oxidation of methyl crotonate, like H₂O₂, CH₃OOH, CH₃OH, and HC(O)OH, are identified, and their mole fractions are reported. Additionally, preliminary modeling is performed which qualitatively captures the observed NTC behavior and reveals future research opportunities.

Identification of a novel immune prognostic model in gastric cancer

PURPOSE

The tumor immune microenvironment (TIME) is now considered as an important factor during gastric cancer (GC) development. This study identified a novel immune-related risk model for predicting prognosis and assessing the immune status of GC patients.

METHODS

Transcriptomic data were obtained from the TCGA database. The differential expressed immune-related genes (IRGs) were identified through the ImmPort portal. Enrichment analysis was performed to explore the potential molecular mechanism of these IRGs. By the Cox regression analysis, we constructed the immune prognostic model. Then, the association between the model and the immune microenvironment was estimated. The model was validated in the GSE84433 dataset.

RESULTS

Totally, we identified 222 differentially expressed IRGs. These IRGs were closely correlated with immune response and immune signaling pathways. Through the Cox regression analysis, we developed the immune prognostic model based on the expression of seven IRGs (CXCL3, NOX4, PROC, FAM19A4, RNASE2, IGHD2-15, CGB5). Patients were stratified into two groups according to immune-related risk scores. Survival analysis indicated that the prognosis of high-risk patients was poorer than low-risk patients. Moreover, the immune-related risk score was an independent prognostic biomarker. More importantly, we found that the infiltration level of immunosuppressive cells and the expression of inhibitory immune checkpoints were higher in high-risk patients. The immune microenvironment tended to be a suppressive status in patients with high-risk scores.

CONCLUSION

This study demonstrated that our model had predictive value for prognosis and the TIME in GC. It might be a robust tool to improve personalized patient management.

Long non-coding RNA FOXP4-AS1 acts as an adverse prognostic factor and regulates proliferation and apoptosis in nasopharyngeal carcinoma

OBJECTIVE

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies worldwide. In The Cancer Genome Atlas (TCGA) database, the expression level of lncRNA forkhead box P4 antisense RNA 1 (FOXP4-AS1) is higher in NPC samples than in normal samples.

PATIENTS AND METHODS

Quantitative Real-time PCR and Western blotting were performed to detect the expression level of RNA and protein. Luciferase reporter assay ran to test the interactions between FOXP4-AS1 and miR-423-5p and STMN1. Subcellular fractionation assay was used to determine the subcellular localization of FOXP4-AS1. The tumor-promotion functions of FOXP4-AS1 were determined by both in vitro and in vivo assays.

RESULTS

The expression of FOXP4-AS1 was up-regulated in 80 cases with NPC, and these patients with a poor prognosis. Functionally, high expression of FOXP4-AS1 in NPC was connected with promoted cell proliferation and inhibited apoptosis. Moreover, FOXP4-AS1 is located in the cytoplasm of CNE1 (NPC cell lines). Mechanistically, FOXP4-AS1 up-regulated STMN1 on post-transcriptional regulation by means of miR-423-5p.

CONCLUSIONS

Our present study demonstrated that high expression of FOXP4-AS1 in NPC portended poor outcomes. FOXP4-AS1upregulated STMN1 by interacting with miR-423-5p as a competing endogenous RNA (ceRNA) to promote NPC progression.