Key message
Hydrogen sulfide closed
Arabidopsis thaliana
stomata by increasing the transcription of melatonin-producing enzymes and the post-translational modification levels to combat osmotic stress
....
Hydrogen sulfide (H
2
S) and melatonin (MEL) reportedly have similar functions in many aspects of plant growth, development and stress response. They regulate stomatal movement and enhance drought resistance. However, their physiological relationship is not well understood. Here, their crosstalk involved in osmotic stress resistance in
Arabidopsis thaliana
was studied. Exogenous H
2
S and MEL closed stomata under normal or osmotic stress conditions and increased the relative water contents of plants under osmotic stress conditions. At the same time, exogenous H
2
S and MEL responded to osmotic stress by increasing the content of proline and soluble sugar, and reducing malondialdehyde (MDA) content and relative conductivity. Using mutants in the MEL-associated production of serotonin
N
-acetyltransferase (
snat
), caffeic acid
O
-methyltransferase (
comt1
) and
N
-acetylserotonin methyltransferase (
asmt
), we determined that H
2
S was partially dependent on MEL to close stomata. Additionally, the overexpression of
ASMT
promoted stomatal closure. Exogenous H
2
S increased the transcription levels of SNAT, ASMT and COMT1. Furthermore, exogenous H
2
S treatments increased the endogenous MEL content significantly. At the post-translational level, H
2
S sulfhydrated the SNAT and ASMT, but not COMT1, enzymes associated with MEL production. Thus, H
2
S appeared to promote stomatal closure in response to osmotic stress by increasing the transcription levels of MEL synthesis-related genes and the sulfhydryl modification of the encoded enzymes. These results increased our understanding of H
2
S and MEL functions and interactions under osmotic stress conditions.
This paper presents U-Pb zircon geochronology, petrology, and major and trace element, Sr-Nd and zircon Hf isotopic geochemistry of Cretaceous granites and intermediate dykes in the Quanzhou and ...Xiamen regions of southeastern China. These data are used to investigate igneous petrogenesis and Cretaceous tectonic evolution, and interpret the geodynamics of Palaeo-Pacific slab subduction. Granites in Quanzhou and Xiamen range in age from 133Ma to 87Ma, have high SiO2 and K2O contents, low abundances in P2O5, and an A/CNK index that ranges from 0.97 to 1.09, indicating that they are high-K calc-alkaline metaluminous I-type rocks. Slightly negative ɛ Nd (t) values (−1.2 to −4.4), young Nd model ages (0.87Ga to 1.20Ga) and positive ɛ Hf (t) values (−0.5 to +9.9) of zircon grains indicate that the granites were derived from magmas that melted amphibolite in the middle-lower crust, and which may have assimilated country rocks during emplacement in shallow chambers. The intermediate dykes have no genetic link to the granites and magma mixing was negligible. Eight dyke samples have low SiO2 and high MgO, Ni and Cr contents. Negative ε Nd (t) values (−1.5 to −2.7) and positive ε Hf (t) values (2.7 to 7.6) suggest that the dykes were derived from residual basic lower crust after mafic-crystal accumulation. Two samples of adakite-like dykes are characterised by high Sr/Y ratios (89 to 100) and high SiO2, low K2O, Ni, Cr contents. In combination with slightly negative ε Nd (t) values (−1.7 to −1.8) and positive ε Hf (t) values (2.9 to 4.3), the adakite-like dykes were derived from cumulate basic lower crust which had a mixed source between depleted mantle- and crust-derived melts. Based on our data, combined with previously published work, we suggest that extension-induced middle-lower crustal melting and underplating of mantle-derived basaltic melts were the principal driving mechanisms for Cretaceous granitic magmatism in coastal Fujian Province. Extension was related to subduction retreat whereas steep slab subduction caused underplating of mantle-derived basaltic melts. These processes were coupled and mainly responsible for the tectonic transition during the Cretaceous from compression to extension in the coastal belt of the Cathaysia Plate.
•Twelve new zircon U-Pb ages of 133–84Ma become younger from inland to coast.•The granites crystallised as I type and derived from middle-lower crust.•Eight intermediate dykes derived from residual basic lower crust after accumulation.•Two adakite-like dykes derived from a mixed lower crust source.•Subduction retreat was principal style of Cretaceous Palaeo-Pacific slab subduction.
assembly plays a pivotal role in metagenomic analysis, and the incorporation of third-generation sequencing technology can significantly improve the integrity and accuracy of assembly results. ...Recently, with advancements in sequencing technology (Hi-Fi, ultra-long), several long-read-based bioinformatic tools have been developed. However, the validation of the performance and reliability of these tools is a crucial concern. To address this gap, we present MCSS (microbial community simulator based on structure), which has the capability to generate simulated microbial community and sequencing datasets based on the structure attributes of real microbiome communities. The evaluation results indicate that it can generate simulated communities that exhibit both diversity and similarity to actual community structures. Additionally, MCSS generates synthetic PacBio Hi-Fi and Oxford Nanopore Technologies (ONT) long reads for the species within the simulated community. This innovative tool provides a valuable resource for benchmarking and refining metagenomic analysis methods.
https://github.com/panlab-bio/mcss.
Colorectal cancer (CRC) is a common malignant tumor, and its incidence ranks third and mortality rate ranks second in the world. Cisplatin cannot target CRC cells and has notable toxicity, which ...significantly limits its clinical application. The emerging PEGylated nanodrug delivery system can improve circulation time and enhance tumor targeting. In this study, the HA-mPEG-Cis NPs were synthesized by self-assembly, which can target CD44-positive CRC cells and dissolve the PEG hydration layer responsive to the weakly acidic tumor environment. The average hydrodynamic diameter of HA-mPEG-Cis NPs was 48 nm with the polydispersity index of 0.13. The in vitro cisplatin release was in a pH-responsive manner. The HA-mPEG-Cis NPs group showed the highest apoptosis rate (25.1%). The HA-mPEG-Cis NPs exhibited antitumor efficacy via the PI3K/AKT/mTOR signaling pathway. The HA-mPEG-Cis NPs showed the lowest tumor volume and weight among all the groups in CT26 cell-bearing mouse model. The HA-mPEG-Cis nanodrug delivery system not only increases the stability and circulation time but also reduces the side effects of loaded cisplatin. Overall, the in vitro and in vivo experiments confirmed the satisfied antitumor efficacy of HA-mPEG-Cis NPs. Therefore, this study provides a rational design for application of pH-responsive HA-mPEG-Cis nanodrug delivery system in the future.
Background
Lymph node metastasis (LNM) often occurs in papillary thyroid carcinoma (PTC); the efficacy of ultrasound for predicting high-volume lymph node metastases (LNMs) in patients with PTC ...remains unexplored.
Methods
The medical records of 2073 consecutive PTC patients were reviewed. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to evaluate the efficacy of ultrasound. Risk factors for LNM/high-volume LNMs and lymph node involvement on ultrasound (usLNM) were identified by univariate and multivariate analyses.
Results
Of all the patients, 936 (45.2%) patients had LNMs, and 254 (12.3%) patients had high-volume LNMs. The sensitivity of ultrasound for detecting LNM/high-volume LNMs was 27.9% and 63.8%, respectively; the specificity was 93.1% and 90.3%, respectively. The NPV for ultrasound in detecting high-volume LNMs was 94.7%. In multivariate analysis, male sex (OR = 2.108,
p
< 0.001), tumor diameter > 1.0 cm (OR = 2.304,
p
< 0.001) and usLNM (+) (OR = 12.553,
p
< 0.001) were independent clinical risk factors for high-volume LNMs. Tumor diameter > 1 cm (OR = 3.036,
p
< 0.001) and male sex (OR = 1.642,
p
< 0.001) were independent clinical risk factors for usLNM; a skilled sonographer (OR = 1.121,
p
= 0.358) was not significantly associated with usLNM.
Conclusions
Lymph node involvement found by ultrasound has great predictive value for high-volume LNMs; the NPV is very high for patients without lymph node involvement on ultrasound. The ultrasound results do not appear to be influenced by the experience of the sonographer.
ORS571 is a motile soil bacterium that interacts symbiotically with legume host
, forming nitrogen-fixing root and stem nodules. Bacterial chemotaxis plays an important role in establishing this ...symbiotic relationship. To determine the contribution of chemotaxis to symbiosis in
ORS571-
, we characterized the function of TlpA1 (transducer-like protein in
), a chemoreceptor predicted by SMART (Simple Modular Architecture Research Tool), containing two N-terminal transmembrane regions. The
gene is located immediately upstream of the unique
gene cluster and is transcriptionally co-oriented. We found that a Δ
mutant is severely impaired for chemotaxis to various organic acids, glycerol and proline. Furthermore, biofilm forming ability of the strain carrying the mutation is reduced under certain growth conditions. Interestingly, competitive colonization ability on
root surfaces is impaired in the Δ
mutant, suggesting that chemotaxis of the
ORS571 contributes to root colonization. We also found that TlpA1 promotes competitive nodulation not only on roots but also on stems of
. Taken together, our data strongly suggest that TlpA1 is a transmembrane chemoreceptor involved in
-
symbiosis.
Diabetic cardiomyopathy (DCM) is a primary cause of death in diabetic patients; however, its molecular mechanism is not yet clear, and there is no uniform standard for diagnosis. The aim of this ...study is to discover the pathogenesis and potential therapeutic targets of DCM through screening and analysis of differentially expressed genes (DEGs) in heart ventricles of DCM, and to testify the role of key hub genes in DCM-induced myocardial dysfunction. Datasets GSE4745 and GSE6880 were downloaded from the GEO database. The difference analysis, visual analysis, cluster analysis and enrichment analysis were performed by using R language, python scripts and bioinformatics software followed by the construction of protein-protein interaction (PPI) network to obtain hub genes. The DCM models were established by streptozocin (STZ) injection to the male mice. The cardiac function and the expressions of hub genes were examined by using echocardiography and real-time quantitative poly-merase chain reaction (RT-qPCR), followed by multiple statistical analyses. Bioinformatic results indicate that mitochondrial dysfunction, disturbed lipid metabolism and decreased collagen synthesis are the main causes of the DCM development. In particular, the hub gene
that encodes Cytochrome P450 1A1 (CYP4501A1) enzyme has the highest connectivity in the interaction network, and is associated with mitochondrial homeostasis and energy metabolism. It plays a critical role in the oxidation of endogenous or exogenous substrates. Our RT-qPCR results confirmed that ventricular
mRNA level was nearly 12-fold upregulated in DCM model compared to normal control, which was correlated with abnormal cardiac function in diabetic individuals. CYP4501A1 protein expression in mitochondria was also increased in diabetic hearts. However, we found no significant changes in collagen expressions in cardiac ventricles of mice with DCM. This study provided compact data support for understanding the pathogenesis of DCM. CYP4501A1 might be considered as a potential candidate targeting for DCM therapy. Follow-up animal and clinical verifications need to be further explored.
Lymph node metastasis (LNM) often occurs in clinical lymph node negative (cN0) papillary thyroid microcarcinoma (PTMC). The risk factors for LNM, especially for high-volume LNM, were investigated in ...this study.
The medical records of 1,974 consecutive PTMC patients admitted to the Peking Union Medical College Hospital (PUMCH) from 2013 to 2015 were reviewed. Their clinicopathological features were collected. Univariate and multivariate analyses were performed to identify the risk factors for LNM/high-volume LNM.
Of all the patients, cervical lymph node metastases were detected in 690 patients (34.95%), and high-volume LNM was detected in 75 patients (3.80%). The results of univariate analysis revealed that sex, age, chronic thyroiditis, multifocality, and tumor diameter were significantly correlated with LNM (P<0.05) and that sex, age, multifocality, and tumor diameter were significantly correlated with high-volume LNM (P<0.05). Multivariate logistic regression analysis demonstrated that male sex odds ratio (OR) =1.657, P<0.001, multifocality (OR =1.601, P<0.001), and tumor diameter >0.5 cm (OR =1.770, P<0.001) were independent risk factors for LNM; age of 40-59 years old (OR =0.427, P<0.001), age ≥60 years old (OR =0.291, P<0.001), and chronic thyroiditis (OR =0.562, P<0.001) were independent protective factors for LNM. For high-volume LNM, male sex (OR =2.250, P=0.002), tumor diameter >0.5 cm (OR =3.664, P=0.013) and multifocality (OR =2.034, P=0.004) were independent risk factors, whereas age ≥40 years old (OR =0.240, P<0.001) was an independent protective factor.
Lymph node metastases are common in cN0 PTMC, whereas high-volume LNM is rare. Active surveillance may be reasonable for patients with tumor diameter ≤0.5 cm, age ≥40 years old, female sex and isolated lesions.
► Exergy balance test was systematically carried out on a GKC plant in China. ► It is the first time that exergy analyses have been conducted to investigate the GKC. ► A model named IOPEM is ...presented according to oxidation kinetic characteristics. ► The maximum difference (−6.8%) of pellet exergy by IOPEM and IMEM arises in the kiln. ► Exergy efficiency (10.7%) indicates a great potential for energy-saving improvements.
Many models of iron ore pellet induration have been developed on the basis of the first law of thermodynamics. However, the exergy analysis, well grounded on the first and second law, of the process is rare. Therefore, exergy balance test was systematically carried out on a grate–kiln, and energy and exergy analyses have been conducted to investigate irreversibility of the process. A model of iron oxide pellet exergy (IOPEM) is presented according to oxidation kinetic characteristics. It is found that the maximum effect (−6.8%) of the characteristics on the pellet exergy appears in the raised end of the kiln. The exergy efficiency of the system is determined to be 10.7% whereas its energy efficiency 59.9%, indicating a great potential for energy-saving improvements. The exergy analysis reveals exergy destruction ratio of kiln and cooler is 14.1%, and 7.7% respectively, and the largest exergy destruction (74.2%) results from the grate. No violent effect of reference environment temperature on exergy efficiency of major components is observed, indicating the grate is the major source of irreversibility. In a word, this study provides a better understanding of the energy and exergy flows of iron ore pellet induration in the grate–kiln and helps to economize energy.
The coupling between hydraulic and mechanical behavior of the fractured rock mass is of great significance for various civil and environmental engineering projects. In order to study the ...hydro-mechanical behavior of single fracture, seepage tests under different confining pressures and fracture water pressures were conducted on single shear fractures produced by triaxial loading of diabase rock samples from Danjiangkou Water Reservoir, China. Test results show that fluid pressure acting on fracture surfaces has strong influences on the hydraulic behavior of the fracture. Based on the classic Biot poroelasticity theory and by taking the fracture as assembling of a set of voids in rock mass, a generalized Biot coefficient is introduced to describe the interaction effect between pore fluid pressure and fracture deformation. Then, a nonlinear constitutive equation for single fracture under both normal stress and fluid pressure is developed. Later, the mechanical deformation of the fracture is related to the fracture hydraulic conductivity through “cubic law”, so that a coupled mechanical-hydraulic model is proposed. All the four parameters involved in this model have their physical significances and can be determined through mechanical compression tests and seepage tests. A first validity of the model is made by predicting the variation of fracture flowrates versus normal stress under different fluid pressures.
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