Accurate estimations of leaf biomass are required to quantify the amount of material and energy exchanged between vegetation and the atmosphere, to enhance the primary productivity of forest stands, ...and to assess the contributions of vegetation towards the mitigation of global climate change. The leaf biomass of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz) changes dramatically during the year owing to changes in the leaves and the growth of new shoots. Furthermore, the relationship between the leaf biomass of Moso bamboo under cutting the top of the culm and the diameter at breast height (D) and culm height is decoupling, which increases the difficulty of estimating leaf biomass. Consequently, an effective method to accurately estimate the leaf biomass of Moso bamboo under cutting the top of the culm is required. In this study, leaf biomass and other factors (age, D, culm height, crown length, and crown width) were measured for 54 bamboo samples collected from December 2019 to December 2020. Models for predicting the leaf biomass of the Moso bamboo were established using multiple linear regression with two strategies, and their accuracies were evaluated using leave-one-out cross-validation. The results showed that crown length, crown width, and age were highly correlated with leaf biomass, and these were important factors when making estimations. Variation in monthly averaged leaf biomass is significant, with a decreasing trend from January to May and an increasing trend from June to December in off-years. The leaf biomass model that utilized data from the three leaf change periods had a better fit and accuracy, with R2 values of 0.583–0.848 and prediction errors between 8.59% and 24.19%. The model that utilized data for all months had a worse fit and accuracy, with an R2 value of 0.228 and prediction error of 46.79%. The results of this study provide reference data and technical support to help clarify the dynamic changes in Moso bamboo leaf biomass, and therefore, aid in the development of accurate simulations.
To understand the prevalence, genetic characteristics and drug resistance features of Salmonella Kentucky ST314 in Shenzhen.
Whole genome sequencing of 14 strains of Salmonella Kentucky ST314 ...collected from 2010-2021 by the Foodborne Disease Surveillance Network of Shenzhen Center for Disease Control and Prevention for phylogenetic evolutionary analysis, drug resistance gene and plasmid detection; drug susceptibility experiments were performed by micro-broth dilution method.
A total of 57 strains of Salmonella Kentucky were collected from the foodborne disease surveillance network, 14 of which were ST314. The Shenzhen isolates were clustered with isolates from Southeast Asian countries such as Vietnam and Thailand on clade 314.2, and the single nucleotide polymorphism distance between local strains in Shenzhen was large, indicating dissemination. In this study, a total of 17 drug resistance genes/mutations in 9 categories were detected in the genome of Salmonella Kentucky ST314, carrying 3 extended spectrum b
In this paper, an innovative method of adopting a piping insert with an abrupt contraction or expansion structure has been proposed to eliminate undesirable thermally driven gas oscillations in ...cryogenic systems. In addition, the influences of the piping inserts’ geometrical parameters and position on the performance of thermoacoustic oscillation in cryogenic systems have been investigated. A series of simulations has been conducted, and simulation bifurcation diagrams show that thermoacoustic oscillation can be completely stopped, which, in other words, is called the amplitude death (AD) phenomenon. When the pipeline inserts are equipped in the cold part, AD can be achieved regardless of the pipeline inserts’ radius. When the pipeline inserts are located in the warm part, AD can be realized by the pipe inserts with an abrupt contraction. The identification of nonlinear characteristics of different state transitions with different insert geometries is further conducted by unfolding these original time series in an embedding space. The nonlinear change process of thermoacoustic oscillation is demonstrated in the phase space diagrams. As the insert radius increases, the system transforms from a periodic state to a quasi-periodic state and then from a quasi-periodic state to an AD state. This work will have practical impacts on the design of oscillation-free piping systems.
In this work, the vanillin cross-linked chitosan microspheres were firstly prepared by emulsion chemical cross-linking method with vanillin as a cross-linker. Subsequently, with polyvinylpyrrolidone ...as a nanoparticle stabilizer and dispersant, silver nanoparticles were modified onto the surface of vanillin cross-linked chitosan microspheres by in situ reduction with ascorbic acid to obtain silver nanoparticles modified microspheres. The chitosan and two kinds of microspheres were characterized by SEM, FTIR and XRD. The SEM images showed that the two kinds of microspheres had clear and well-defined spherical shapes with an average particle size of 4.2 μm and the silver nanoparticles were then evenly dispersed on the surface. The FTIR spectra revealed that chitosan was successfully cross-linked by vanillin through Schiff base reaction and hydrogen bond interactions. The X-ray diffraction pattern of vanillin cross-linked chitosan microspheres modified with silver nanoparticles indicated that the silver nanoparticles had a face-centred cubic structure with an average particle size of 44.4 nm confirmed by SEM, which proved the successful synthesis of target composite microspheres.
Anaplastic thyroid cancer (ATC) is one of the most aggressive of all solid tumors for which no effective therapies are currently available. Oncolytic Newcastle disease virus (NDV) has shown the ...potential to induce oncolytic cell death in a variety of cancer cells of diverse origins. However, whether oncolytic NDV displays antitumor effects in ATC remains to be investigated. We have previously shown that the oncolytic NDV strain FMW (NDV/FMW) induces oncolytic cell death in several cancer types. In the present study, we investigated the oncolytic effects of NDV/FMW in ATC.
In this study, a recombinant NDV expressing green fluorescent protein (GFP) was generated using an NDV reverse genetics system. The resulting virus was named after rFMW/GFP and the GFP expression in infected cells was demonstrated by direct fluorescence and immunoblotting. Viral replication was evaluated by end-point dilution assay in DF-1 cell lines. Oncolytic effects were examined by biochemical and morphological experiments in cultural ATC cells and in mouse models.
rFMW/GFP replicated robustly in ATC cells as did its parent virus (NDV/FMW) while the expression of GFP protein was detected in lungs and spleen of mice intravenously injected with rFMW/GFP. We further showed that rFMW/GFP infection substantially increased early and late apoptosis in the ATC cell lines, THJ-16 T and THJ-29 T and increased caspase-3 processing and Poly (ADP-ribose) polymerase (PARP) cleavage in ATC cells as assessed by immunoblotting. In addition, rFMW/GFP induced lyses of spheroids derived from ATC cells in three-dimensional (3D) cultures. We further demonstrated that rFMW/GFP infection resulted in the activation of p38 MAPK signaling, but not Erk1/2 or JNK, in THJ-16 T and THJ-29 T cells. Notably, inhibition of p38 MAPK activity by SB203580 decreased rFMW/GFP-induced cleavage of caspase-3 and PARP in THJ-16 T and THJ-29 T cells. Finally, both rFMW/GFP and its parent virus inhibited tumor growth in mice bearing THJ-16 T derived tumors.
Taken together, these data indicate that both the recombinant reporter virus rFMW/GFP and its parent virus NDV/FMW, display oncolytic activities in ATC cells in vitro and in vivo and suggest that oncolytic NDV may have potential as a novel therapeutic strategy for ATC.
As the most abundant internal mRNA modification, N6-methyladenosine (m6A) was involved in almost all the aspects of RNA metabolism. Here, we introduce our protocol for m6A-SAC-seq, which enables the ...whole transcriptome-wide mapping of m6A RNA modification at single-nucleotide resolution with stoichiometry information. m6A-SAC-seq relies on selective allyl labeling of m6A by specific methyltransferase and chemical treatment that introduce mutation upon reverse transcription. The technique only requires ∼30 ng of input RNA.
For complete details on the use and execution of this protocol, please refer to Hu et al. (2022).
Display omitted
•A protocol to label RNA m6A with allyl group•Incorporate mismatch and detect m6A at single-nucleotide resolution•Provide stoichiometric information of individual m6A sites with spike-in calibration•An optimized assay to detect and quantitate RNA m6A with only ∼ 30 ng input RNA
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
As the most abundant internal mRNA modification, N6-methyladenosine (m6A) was involved in almost all the aspects of RNA metabolism. Here, we introduce our protocol for m6A-SAC-seq, which enables the whole transcriptome-wide mapping of m6A RNA modification at single-nucleotide resolution with stoichiometry information. m6A-SAC-seq relies on selective allyl labeling of m6A by specific methyltransferase and chemical treatment that introduce mutation upon reverse transcription. The technique only requires ∼30 ng of input RNA.
N7-methylguanosine (m7G) is a positively charged, essential modification at the 5′ cap of eukaryotic mRNA, regulating mRNA export, translation, and splicing. m7G also occurs internally within tRNA ...and rRNA, but its existence and distribution within eukaryotic mRNA remain to be investigated. Here, we show the presence of internal m7G sites within mammalian mRNA. We then performed transcriptome-wide profiling of internal m7G methylome using m7G-MeRIP sequencing (MeRIP-seq). To map this modification at base resolution, we developed a chemical-assisted sequencing approach that selectively converts internal m7G sites into abasic sites, inducing misincorporation at these sites during reverse transcription. This base-resolution m7G-seq enabled transcriptome-wide mapping of m7G in human tRNA and mRNA, revealing distribution features of the internal m7G methylome in human cells. We also identified METTL1 as a methyltransferase that installs a subset of m7G within mRNA and showed that internal m7G methylation could affect mRNA translation.
Display omitted
•Presence of internal m7G in mammalian mRNA•Chemical-assisted m7G-seq maps m7G methylome at single-base resolution•Highly modified internal m7G sites were identified in human mRNA•METTL1 acts as a methyltransferase for a subset of internal m7G sites in mRNA
Zhang et al. discovered the presence of internal N7-methylguanosine (m7G) within mammalian mRNA. Both antibody-based and chemical-assisted methods were developed for transcriptome-wide mapping of internal m7G, with the latter reaching single-base resolution. METTL1/WDR4 was identified as a writer complex that installs a subset of m7G on mRNA, which affects translation.
The efficacy of osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, has been evaluated in glioblastoma (GBM) through preclinical and clinical trials. However, ...the underlying mechanism of osimertinib-induced GBM cell death and the underlying resistance mechanism to osimertinib remains unclear. Here, we demonstrate that Osimertinib induces paraptosis in GBM cells, as evidenced by the formation of cytoplasmic vacuoles, accumulation of ubiquitinated proteins, and upregulation of endoplasmic reticulum (ER) stress markers like CHOP. Additionally, neither apoptosis nor autophagy was involved in the osimertinib-induced cell death. RNAseq analysis revealed ER stress was the most significantly downregulated pathway upon exposure to osimertinib. Consistently, pharmacologically targeting the PERK-eIF2α axis impaired osimertinib-induced paraptosis. Notably, we show that the expression of thyroid receptor-interacting protein 13 (TRIP13), an AAA+ATPase, alleviated osimertinib-triggered paraptosis, thus conferring resistance. Intriguingly, MK-2206, an AKT inhibitor, downregulated TRIP13 levels and synergized with Osimertinib to suppress TRIP13-induced high GBM cell growth in vitro and in vivo. Together, our findings reveal a novel mechanism of action associated with the anti-GBM effects of osimertinib involving ER stress-regulated paraptosis. Furthermore, we identify a TRIP13-driven resistance mechanism against Osimertinib in GBM and offer a combination strategy using MK-2206 to overcome such resistance.
PDF
