Amphiphilic AIE Fluorescent Probe: A Dual-Functionality Strategy for Efficient Antibacterial Therapy Fluorescence Bioimaging against Staphylococcus aureus.

Drug-resistant bacteria present a grave threat to human health. Fluorescence imaging-guided photodynamic antibacterial therapy holds enormous potential as an innovative treatment in antibacterial therapy. However, the development of a fluorescent material with good water solubility, large Stokes shift, bacterial identification, and high photodynamic antibacterial efficiency remains challenging. In this study, we successfully synthesized an amphiphilic aggregation-induced emission (AIE) fluorescent probe referred to as NPTPA-QM. This probe possesses the ability to perform live-bacteria fluorescence imaging while also exhibiting antibacterial activity, specifically against Staphylococcus aureus (S. aureus). We demonstrate that NPTPA-QM can eliminate S. aureus at a very low concentration (2 µmol L-1). Moreover, it can effectively promote skin wound healing. Meanwhile, this NPTPA-QM exhibits an excellent imaging ability by simple mixing with S. aureus. In summary, this research presents a straightforward and highly effective method for creating "amphiphilic" AIE fluorescent probes with antibacterial properties. Additionally, it offers a rapid approach for imaging bacteria utilizing red emission.

Anti-inflammatory properties and characterization of water extracts obtained from Callicarpa kwangtungensis Chun using in vitro and in vivo rat models.

Callicarpa kwangtungensis Chun (CK) is a common remedy exhibits anti-inflammatory properties and has been used in Chinese herbal formulations, such as KangGongYan tablets. It is the main component of KangGongYan tablets, which has been used to treat chronic cervicitis caused by damp heat, red and white bands, cervical erosion, and bleeding. However, the anti-inflammatory effects of CK water extract remains unknown. This study assessed the anti-inflammatory effects of CK in vivo and in vitro, characterized its main components in the serum of rats and verified the anti-inflammatory effects of serum containing CK. Nitric oxide (NO), tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) release by RAW264.7 cells was examined by ELISA and Griess reagents. Inflammation-related protein expression in LPS-stimulated RAW264.7 cells was measured by western blotting. Furthermore, rat model of foot swelling induced by λ-carrageenan and a collagen-induced arthritis (CIA) rat model were used to explore the anti-inflammatory effects of CK. The components of CK were characterized by LC-MS, and the effects of CK-containing serum on proinflammatory factors levels and the expression of inflammation-related proteins were examined by ELISA, Griess reagents and Western blotting. CK suppressed IL-6, TNF-α, and NO production, and iNOS protein expression in LPS-stimulated RAW264.7 cells. Mechanistic studies showed that CK inhibited the phosphorylation of ERK, P38 and JNK in the MAPK signaling pathway, promoted the expression of IκBα in the NF-κB signaling pathway, and subsequently inhibited the expression of iNOS, thereby exerting anti-inflammatory effects. Moreover, CK reduced the swelling rates with λ-carrageenan induced foot swelling, and reduced the arthritis score and incidence in the collagen-induced arthritis (CIA) rat model. A total of 68 compounds in CK water extract and 31 components in rat serum after intragastric administration of CK were characterized. Serum pharmacological analysis showed that CK-containing serum suppressed iNOS protein expression and NO, TNF-α, and IL-6 release. CK may be an anti-inflammatory agent with therapeutic potential for acute and chronic inflammatory diseases, especially inflammatory diseases associated with MAPK activation.

Porphyrin-based covalent organic frameworks from design, synthesis to biological applications.

Covalent organic frameworks (COFs) constitute a class of highly functional porous materials composed of lightweight elements interconnected by covalent bonds, characterized by structural order, high crystallinity, and large specific surface area. The integration of naturally occurring porphyrin molecules, renowned for their inherent rigidity and conjugate planarity, as building blocks in COFs has garnered significant attention. This strategic incorporation addresses the limitations associated with free-standing porphyrins, resulting in the creation of well-organized porous crystal structures with molecular-level directional arrangements. The unique optical, electrical, and biochemical properties inherent to porphyrin molecules endow these COFs with diversified applications, particularly in the realm of biology. This review comprehensively explores the synthesis and modulation strategies employed in the development of porphyrin-based COFs and delves into their multifaceted applications in biological contexts. A chronological depiction of the evolution from design to application is presented, accompanied by an analysis of the existing challenges. Furthermore, this review offers directional guidance for the structural design of porphyrin-based COFs and underscores their promising prospects in the field of biology.

Evaluating effects of tetrabromobisphenol A and microplastics on anaerobic granular sludge: Physicochemical properties, microbial metabolism, and underlying mechanisms.

Tetrabromobisphenol A (TBBPA) and microplastics are emerging contaminants of widespread concern. However, little is known about the effects of combined exposure to TBBPA and microplastics on the physicochemical properties and microbial metabolism of anaerobic granular sludge. This study investigated the effects of TBBPA, polystyrene microplastics (PS MP) and polybutylene succinate microplastics (PBS MP) on the physicochemical properties, microbial communities and microbial metabolic levels of anaerobic granular sludge. The results showed that chemical oxygen demand (COD) removal of sludge was lowest in the presence of TBBPA alone and PS MP alone with 33.21% and 30.06%, respectively. The microorganisms promoted the secretion of humic substances under the influence of TBBPA, PS MP and PBS MP. The lowest proportion of genes controlling glycolytic metabolism in sludge was 1.52% when both TBBPA and PS MP were added. Microbial reactive oxygen species were increased in anaerobic granular sludge exposed to MPS. In addition, TBBPA treatment decreased electron transfer of the anaerobic granular sludge and disrupted the pathway of anaerobic microorganisms in acquiring adenosine triphosphate, and MPs attenuated the negative effects of TBBPA on the acetate methanogenesis process of the anaerobic granular sludge. This study provides a reference for evaluating the impact of multiple pollutants on anaerobic granular sludge.

TSPAN8+ myofibroblastic cancer-associated fibroblasts promote chemoresistance in patients with breast cancer.

Cancer-associated fibroblasts (CAFs) are abundant stromal cells in the tumor microenvironment that promote cancer progression and relapse. However, the heterogeneity and regulatory roles of CAFs underlying chemoresistance remain largely unclear. Here, we performed a single-cell analysis using high-dimensional flow cytometry analysis and identified a distinct senescence-like tetraspanin-8 (TSPAN8)+ myofibroblastic CAF (myCAF) subset, which is correlated with therapeutic resistance and poor survival in multiple cohorts of patients with breast cancer (BC). TSPAN8+ myCAFs potentiate the stemness of the surrounding BC cells through secretion of senescence-associated secretory phenotype (SASP)-related factors IL-6 and IL-8 to counteract chemotherapy. NAD-dependent protein deacetylase sirtuin 6 (SIRT6) reduction was responsible for the senescence-like phenotype and tumor-promoting role of TSPAN8+ myCAFs. Mechanistically, TSPAN8 promoted the phosphorylation of ubiquitin E3 ligase retinoblastoma binding protein 6 (RBBP6) at Ser772 by recruiting MAPK11, thereby inducing SIRT6 protein destruction. In turn, SIRT6 down-regulation up-regulated GLS1 and PYCR1, which caused TSPAN8+ myCAFs to secrete aspartate and proline, and therefore proved a nutritional niche to support BC outgrowth. By demonstrating that TSPAN8+SIRT6low myCAFs were tightly associated with unfavorable disease outcomes, we proposed that the combined regimen of anti-TSPAN8 antibody and SIRT6 activator MDL-800 is a promising approach to overcome chemoresistance. These findings highlight that senescence contributes to CAF heterogeneity and chemoresistance and suggest that targeting TSPAN8+ myCAFs is a promising approach to circumvent chemoresistance.

Sinomenine Hydrochloride Protects IgA Nephropathy Through Regulating Cell Growth and Apoptosis of T and B Lymphocytes.

Purpose: Sinomenine hydrochloride (SH) is used to treat chronic inflammatory diseases such as rheumatoid arthritis and may also be efficacious against Immunoglobulin A nephropathy (IgAN). However, no trial has investigated the molecular mechanism of SH on IgAN. Therefore, this study aims to investigate the effect and mechanism of SH on IgAN. Methods: The pathological changes and IgA and C3 depositions in the kidney of an IgAN rat model were detected by periodic acid-Schiff (PAS) and direct immunofluorescence staining. After extracting T and B cells using immunomagnetic beads, we assessed their purity, cell cycle phase, and apoptosis stage through flow cytometry. Furthermore, we quantified cell cycle-related and apoptosis-associated proteins by Western blotting. Results: SH reduced IgA and C3 depositions in stage 4 IgAN, thereby decreasing inflammatory cellular infiltration and mesangial injury in an IgAN model induced using heteroproteins. Furthermore, SH arrested the cell cycle of lymphocytes T and B from the spleen of IgAN rats. Regarding the mechanism, our results demonstrated that SH regulated the Cyclin D1 and Cyclin E1 protein levels for arresting the cell cycle and it also regulated Bax and Bcl-2 protein levels, thus increasing Cleaved caspase-3 protein levels in Jurkat T and Ramos B cells. Conclusion: SH exerts a dual regulation on the cell cycle and apoptosis of T and B cells by controlling cell cycle-related and apoptosis-associated proteins; it also reduces inflammatory cellular infiltration and mesangial proliferation. These are the major mechanisms of SH in IgAN.

CRL4DCAF13 E3 ubiquitin ligase targets MeCP2 for degradation to prevent DNA hypermethylation and ensure normal transcription in growing oocytes.

The DNA methylation is gradually acquired during oogenesis, a process sustained by successful follicle development. However, the functional roles of methyl-CpG-binding protein 2 (MeCP2), an epigenetic regulator displaying specifical binding with methylated DNA, remains unknown in oogenesis. In this study, we found MeCP2 protein was highly expressed in primordial and primary follicle, but was almost undetectable in secondary follicles. However, in aged ovary, MeCP2 protein is significantly increased in both oocyte and granulosa cells. Overexpression of MeCP2 in growing oocyte caused transcription dysregulation, DNA hypermethylation, and genome instability, ultimately leading to follicle growth arrest and apoptosis. MeCP2 is targeted by DCAF13, a substrate recognition adaptor of the Cullin 4-RING (CRL4) E3 ligase, and polyubiquitinated for degradation in both cells and oocytes. Dcaf13-null oocyte exhibited an accumulation of MeCP2 protein, and the partial rescue of follicle growth arrest induced by Dcaf13 deletion was observed following MeCP2 knockdown. The RNA-seq results revealed that large amounts of genes were regulated by the DCAF13-MeCP2 axis in growing oocytes. Our study demonstrated that CRL4DCAF13 E3 ubiquitin ligase targets MeCP2 for degradation to ensure normal DNA methylome and transcription in growing oocytes. Moreover, in aged ovarian follicles, deceased DCAF13 and DDB1 protein were observed, indicating a potential novel mechanism that regulates ovary aging.

Water quality drives the reconfiguration of riverine planktonic microbial food webs.

The food web is a cycle of matter and energy within river ecosystems. River environmental changes resulting from human activities are increasingly threatening the composition and diversity of global aquatic organisms and the multi-trophic networks. How multiple environmental factors influence food web patterns among multi-trophic microbial communities in rivers remains largely unknown. Using water quality evaluation and meta-omics techniques, we investigated the composition, structure and interaction characteristics, and drivers of food webs of microorganisms (archaea, bacteria, fungi, protists, metazoa, viridiplantae and viruses) at multiple trophic levels in different water quality environments (Classes II, III, and IV). First, water quality deterioration led to significant changes in the composition of the microbial community at multiple trophic levels, which were represented by the enrichment of Euryarchaeota in the archaeal community, the increase of r-strategists in the bacterial community, and the increase of the proportion of predators in the protist community. Second, deteriorating water quality resulted in a significant reduction in the dissimilarity of community structure (homogenization of community structure in Class III and IV waters). Of the symbiotic, parasitic, and predatory networks, the community networks in Class II water all showed the most stable symbiotic, parasitic, and predatory correlations (higher levels of modularity in the networks). In Class III and IV waters, nutrient inputs have led to increased reciprocal symbiosis and decreased competition between communities, which may have the risk of a positive feedback loop driving a system collapse. Finally, inputs of phosphorus and organic matter could be the main drivers of changes in the planktonic microbial food web in the Fen River. Overall, the results indicated the potential ecological risks of exogenous nutrient inputs, which were important for aquatic ecosystem conservation.

Three new species and two newly recorded species of Tachininae from Tibet, China (Arthropoda, Insecta, Diptera, Tachinidae).

During our studying of the fauna of Tibet, China, many specimens of the subfamily Tachininae (Diptera, Tachinidae) were collected and examined. Three species are described here as new to science, Leskialatisurstylasp. nov., Trichoformosomyiacuonaensissp. nov., and Tachinajilongensissp. nov., and two species, Nemoraeajavana (Brauer & Bergenstamm, 1894) and N.echinata Mesnil, 1953, are newly recorded from Tibet. In addition to their descriptions, illustrations, and diagnoses, three identification keys are provided. The specimens in this study are kept in the Insect Collection of Shenyang Normal University, China (SYNU).

Research on the Influence of Heterogeneity and Viscosity on the Fluid Intrusion Mechanism of the Water Flooding Process Based on the Microscopic Visualization Experiment.

The flow law of immiscible fluids in porous media plays an important role in the development of oil and gas fields. In the process of water flooding reservoir development, when the water phase displaces the oil phase, a fluid with higher viscosity, as a fluid with lower viscosity, the oil-water interface will always be unstable, resulting in different fingering effects. After water flooding, the distribution law of oil and water in the reservoir is mainly affected by the fluid intrusion mechanism. Due to the difference of capillary force, viscous force, and other microscopic forces, the fluid intrusion mechanism is mainly divided into two types: viscous fingering and capillary fingering. At the same time, due to the influence of reservoir heterogeneity, the fingering effect in the process of water displacement in porous media will be influenced to a certain extent. Based on the two-dimensional microscopic visualization experiment, this paper extracted the variance of the static parameter G in the capillary number calculation method of the two-dimensional microscopic model to represent the heterogeneity and conducted displacement experiments with different viscosities and flow rates to study the influence of the flow rate, viscosity, and heterogeneity on the results of water flooding. The experiments found that as for the influence of flow velocity, with the increase of flow velocity, that is, with the increase of capillary number, the recovery degree decreases first and then increases. As for the influence of viscosity, from a numerical point of view, the displacement efficiency and conformance coefficient of the low-viscosity group are higher than those of the high-viscosity group. From the trend, with the increase of the capillary number, the displacement efficiency of both the low-viscosity and high-viscosity groups increases, while the conformance coefficient decreases first and then increases, indicating that capillary fingering and viscous fingering can occur in different viscosity reservoirs. As for the influence of heterogeneity, the conformance coefficient of the water flooding decreases with the increase of heterogeneity, and the viscous pointing trend caused by heterogeneity is stronger, resulting in an uneven water injection sweep and higher oil displacement efficiency within the swept area. It can be seen from the fluid intrusion mechanism diagram that with the increase of heterogeneity, the viscous fingering trend becomes more obvious; with the increase of viscosity, the fluid intrusion mechanism boundary moves down and the viscous fingering trend becomes more obvious.

Temperature and moisture sensitivities of soil respiration vary along elevation gradients: An analysis from long-term field observations.

Based on long-term field observation data over 11 years at 23 sites in two mountainous areas (TS1 and TS2) at elevations from 829 to 2700 m, where the dominant vegetation type of TS1 and TS2 was temperate mixed broadleaf-coniferous forest and cold temperate coniferous forest, respectively, we analyzed the correlations between soil respiration (Rs) and abiotic and biotic factors to explore the response patterns of Rs to environmental factors within and between the sites along the elevation gradient. We found that soil moisture (θ) and its combinations (Ts × Î¸ and θ/Ts) with soil temperature (Ts) increased significantly with increasing elevation, while Ts, soil bulk density (SBD), C/N ratio, and pH decreased significantly with increasing elevation. Within each site, both exponential- Ts (ET) and Gaussian-Ts (GT) models could be used for predicting the Rs seasonal variation, except for two sites in the area of TS1, where θ was a better predictor than Ts. The integrated ET-θ and GT-θ models could be applied to all sites except for 22S, and both were superior to the ET and GT models. The mean Rs of each site over the measurement period ranged from 3.07 to 6.94 µmol CO2 m-2 s-1 and showed a quadratic increase along the elevation gradient. Among the 23 sites, Q10 ranged from 1.15 to 3.79, and it increased with elevation, reaching a maximum at an elevation of 2366 m; the θ sensitivity parameter (d) decreased significantly with elevation and reached a minimum at an elevation of 1975 m. Both the d and Ts sensitivity parameter (b) of Rs were complementary to each other along the elevation gradient. Among the sites, Ts, θ, and combinations of the two were more important drivers for both Rs and Q10 variations than microbial and physicochemical indicators.

Toxicity factors to assess the ecological risk for soil microbial communities.

The toxicity factor (TF), a critical parameter within the potential ecological risk index (RI), is determined without accounting for microbial factors. It is considerable uncertainty exists concerning its validity for quantitatively assessing the influence of metal(loid)s on microorganisms. To evaluate the suitability of TF, we constructed microcosm experiments with varying RI levels (RI = 100, 200, 300, 500, and 700) by externally adding zinc (Zn), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd), and mercury (Hg) to uncontaminated soil (CK). Quantitative real-time PCR (qPCR) and high-throughput sequencing techniques were employed to measure the abundance and community of bacteria and fungi, and high-throughput qPCR was utilised to quantify functional genes associated with CNPS cycles. The results demonstrated that microbial diversity and function exhibited significant alterations (p < 0.05) in response to increasing RI levels, and the influences on microbial community structure, enzyme activity, and functional gene abundances were different due to the types of metal(loid)s treatments. At the same RI level, significant differences (p < 0.05) were discerned in microbial diversity and function across metal(loid) treatments, and these differences became more pronounced (p < 0.001) at higher levels. These findings suggest that TF may not be suitable for the quantitative assessment of microbial ecological risk. Therefore, we adjusted the TF by following three steps (1) determining the adjustment criteria, (2) deriving the initial TF, and (3) adjusting and optimizing the TF. Ultimately, the optimal adjusted TF was established as Zn = 1.5, Cr = 4.5, Cu = 6, Pb = 4.5, Ni = 5, Cd = 22, and Hg = 34. Our results provide a new reference for quantitatively assessing the ecological risks caused by metal(loid)s to microorganisms.

Synthesis of Azepino[4,5-b]indole via Ring Expansion of Tetrahydro-ß-carbolines Ammonium Ylide.

The formal cyclization strategy was generally used to construct azepino[4,5-b]indole. Herein, we reported a novel and expeditious protocol for the synthesis of quaternary carbon azepino[4,5-b]indole via ring expansion of ammonium ylide, which was formed by the reaction of tetrahydro-ß-carbolines with the diazo compound. The easily available substrates, mild reaction conditions, and broad functional tolerance rendered this method a practical strategy that may significantly afford an efficient method of scaffold hopping in drug discovery.

Genome-Wide Analysis of bHLH Family Genes and Identification of Members Associated with Cold/Drought-Induced Photoinhibition in Kandelia obovata.

Plant basic helix-loop-helix (bHLH) transcription factors play pivotal roles in responding to stress, including cold and drought. However, it remains unclear how bHLH family genes respond to these stresses in Kandelia obovata. In this study, we identified 75 bHLH members in K. obovata, classified into 11 subfamilies and unevenly distributed across its 18 chromosomes. Collineation analysis revealed that segmental duplication primarily drove the expansion of KobHLH genes. The KobHLH promoters were enriched with elements associated with light response. Through RNA-seq, we identified several cold/drought-associated KobHLH genes. This correlated with decreased net photosynthetic rates (Pn) in the leaves of cold/drought-treated plants. Weighted gene co-expression network analysis (WGCNA) confirmed that 11 KobHLH genes were closely linked to photoinhibition in photosystem II (PS II). Among them, four Phytochrome Interacting Factors (PIFs) involved in chlorophyll metabolism were significantly down-regulated. Subcellular localization showed that KobHLH52 and KobHLH30 were located in the nucleus. Overall, we have comprehensively analyzed the KobHLH family and identified several members associated with photoinhibition under cold or drought stress, which may be helpfulfor further cold/drought-tolerance enhancement and molecular breeding through genetic engineering in K. obovata.

Removal of the rate table: MEMS gyrocompass with virtual maytagging.

High-performance micro-electro-mechanical system (MEMS) gyrocompasses for north-finding systems have been very popular for decades. In this paper, a MEMS north-finding system (NFS) based on virtual maytagging (VM) is presented for the first time. In stark contrast to previous schemes of MEMS-based NFSs (e.g., carouseling, maytagging) and the abandoning rate table, we developed a honeycomb disk resonator gyroscope (HDRG) and two commercial accelerometers for azimuth detection. Instead of the physical rotation of the integrated turntable in traditional NFSs, the vibratory working modes of the HDRG are rotated periodically with electronic control to reduce the uncertainty in the azimuth. After systematically analyzing the principle of NFSs with VM, we designed tests to verify the practicability at the sensor level. A bias instability of 0.0078°/h can be obtained during one day with VM in an HDRG. We also implemented comparative north-finding experiments to further check our strategy at the system level. The accuracy in the azimuth can reach 0.204° for 5 min at 28.2° latitude with VM and 0.172° with maytagging. The results show that without any mechanical turning parts, VM technology makes it possible to develop high-precision handheld MEMS NFSs.

Anti-Herpes Simplex Virus Type 1 Activity Evaluation of Natural Derived Phloroglucinol Derivatives and Their Molecular Mechanisms Study.

HSV-1 is a common infection that can cause cold sores. In this study, the anti-HSV-1 virus activity of three series compounds A1-A9, B1-B12, C1-C22 was screened by MTT assay, qRT-PCR assay, Western blot assay and viruses' plaque assays. The results of MTT assay disclosed that phloroglucinol derivatives C2 and C3 effectively inhibited the death of HSV-1 infected vero cells with the CC50 values of C2 and C3 were 72.64 µmol/L and 32.62 µmol/L in HaCaT cells, 137.6 µmol/L and 48.55 µmol/L in Hela cells. The IC50 values of C3 in vero cells and Hela cells were 19.26 µmol/L and 22.98 µmol/L, respectively. In the qRT-PCR experiments, it showed that C2 and C3 effectively reduced the synthesis of HSV-1 early viral gene VP16 and late viral gene gD. The Western blot results showed that both C2 and C3 inhibited the expression of HSV-1 gD protein in a concentration-dependent manner. Lastly, viruses' plaque assay results showed that C2 and C3 inhibited the production of HSV-1 progeny virus in Hela cells and HaCaT cells in a concentration-dependent manner. Taken together, these results suggest that C2 and C3 are promising candidate that warrants further attention in the development of anti-HSV-1 drugs.

Taxonomic study of the genus Macquartia Robineau-Desvoidy (Diptera, Tachinidae) from China.

Background: The genus Macquartia Robineau-Desvoidy (Diptera, Tachinidae) with 29 known species is a large group of Macquartiini of Tachininae and widely distributed in the Old World and the Nearctic Region. New information: In this study, Chinese specimens of Macquartia were collected and examined, sixteen species are recognised: thirteen previously described, M.brunneisqua Zhang et Li, M.chinensis Zhang et Li, M.flavifemorata Zhang et Li, M.flavipedicel Zhang et Li, M.chalconota (Meigen), M.dispar (Fallén), M.grisea (Fallén), M.macularis Villeneuve, M.nudigena Mesnil, M.picta (Meigen), M.pubiceps (Zetterstedt), M.tenebricosa (Meigen) and M.viridana Robineau-Desvoidy and three species new to science, M.barkamensis sp. n. (Sichuan), M.setifacies sp. n. (Qinghai) and M.sichuanensis sp. n. (Sichuan). An identification key to the sixteen species of Macquartia known from China is included, along with 80 anatomical figures.

Drought-resistant trait of different crop genotypes determines assembly patterns of soil and phyllosphere microbial communities.

Crop microbiomes are widely recognized to play a role in crop stress resistance, but the ecological processes that shape crop microbiomes under water stress are unclear. Therefore, we investigated the bacterial communities of two oat (Avena sativa) and two wheat (Triticum aestivum) genotypes under different water stress conditions. Our results show that the microbial assemblage was determined by the crop compartment niche. Host selection pressure on the bacterial community increased progressively from soil to epiphyte to endophyte pathways, leading to a decrease in bacterial community diversity and network complexity. Source tracing shows that soil is the primary source of crop microbial communities and that bulk soil is the main potential source of crop microbiota. It filters gradually through the different compartment niches of the crop. We found that the phyla Actinobacteria, Proteobacteria, Gemmatimonadota, and Myxococcota were significantly enriched in bacterial communities associated with crop-resistance enzyme activity. Crop genotype influenced the composition of the rhizosphere soil microbial community, and the composition of the phylloplane microbial community was affected by water stress. IMPORTANCE In this paper, we investigated the assembly of the plant microbiome in response to water stress. We found that the determinant of microbiome assembly under water stress was the host type and that microbial communities were progressively filtered and enriched as they moved from soil to epiphyte to endophyte communities, with the main potential source being bulk soil. We also screened for bacterial communities that were significantly associated with crop enzyme activity. Our research provides insights into the manipulation of microbes in response to crop resistance to water stress.

Responses of soil bacterial community structure to different artificially restored forests in open-pit coal mine dumps on the loess plateau, China.

Artificial vegetation restoration is an effective method for improving soil quality. In areas experiencing coal mine subsidence, the microbial community is essential for reconstructing the ecological balance of the soil. Studies are needed to examine how soil microbial community structure respond to different artificial forest restoration types and ages, especially over long-term periods. Therefore, in this study, 10, 20, and 30-year trials were chosen with two restoration types: Pinus tabuliformis (PT) and Ulmus pumila (UP). The objective was to determine how various types and ages of forest restoration affect the structure of soil bacterial communities, as well as the soil environmental factors driving these changes. The results showed that artificial 30-year restoration for both PT and UP can improve soil physical and chemical properties more than restoration after 10 and 20 years. The soil bacterial community structure remarkably differed among the different forest types and restoration ages. The bacterial diversity was higher in UP than in PT; the alpha diversity at longer restoration years (30 and 20) was significantly higher than at 10 years for both PT and UP. Moreover, soil nutrients and pH were the primary soil environmental factors driving bacterial community structure in the PT and UP. Finally, the integrated fertility index (IFI) at 30 years of restoration was considerably higher for PT and UP, and thus, is more beneficial to the restoration of soil after coal mining. Our findings are useful for studying improvement in soil quality and the restoration of the ecological environment in mining areas.

Molecular Dynamics Simulations of the Thermal Decomposition of RDX/HTPB Explosives.

The addition of binders to energetic materials is known to complicate the thermal decomposition process of such materials. To assess this effect, the present work studied the thermal decomposition of cyclotrimethylene trinitramine (RDX)/hydroxy-terminated polybutadiene (HTPB) mixtures and of pure RDX over the temperature range of 2000-3500 K by combining the classical reaction and first-principles molecular dynamics methods. The incorporation of HTPB as a binder was found to significantly reduce the decomposition rate of RDX. At 3500 K, the decay rate constant of RDX in the RDX/HTPB system is 2.0141 × 1012 s-1, while it is 2.7723 × 1012 s-1 in the pure RDX system. However, the binder HTPB had little effect on the initial decomposition mechanism, which involved the rupture of N-NO2 bonds to produce NO2. The HTPB was predicted to undergo dehydrogenation and chain breaking. The free H resulting from these processes was predicted to react with low-molecular-weight intermediates generated by the RDX, resulting in greater equilibrium quantities of the final products H2O and H2 being obtained from the mixed system compared with pure RDX. HTPB-chain fragments were also found to combine with the primary RDX decomposition product NO2 to inhibit the formation of N2 and CO2.