Advances in Research on Synthetic Microbial Communities

The synthetic microbial community is a synthetic microbial system co-cultured with multiple species, which has the characteristics of clear composition and strong controllability. Compared with a single colony, it can achieve more complex functions and adapt to the changing environment more easily, so as to meet a wide range of needs. In this paper, the contents and concepts of microbial community and synthetic microbial community are briefly introduced, the principles that should be followed in the construction of microbial community are expounded, the methods and mathematical models used in the construction of synthetic microbial community are introduced, and the applications of synthetic microbial community in various fields are summarized. Finally, the challenges in the research of synthetic microbial communities are briefly described.

The Preliminary Study on Screening and Application of Phthalic Acid-Degrading Bacteria

Phthalic acid is a main pollutant, which is also an important reason for the continuous cropping effect of tobacco. In order to degrade the phthalic acid accumulated in the environment and relieve the obstacle effect of tobacco continuous cropping caused by the accumulation of phthalic acid in the soil. In this study, phthalate degrading bacteria B3 is screened from continuous cropping tobacco soil. The results of biochemical identification and 16sDNA comparison show that the homology between degrading bacterium B3 and Enterobacter sp. is 99%. At the same time, the growth of Enterobacter hormaechei subsp. B3 and the degradation of phthalic acid under different environmental conditions are studied. The results show that the environment with a temperature of 30˚C, PH of 7, and inoculation amount of not less than 1.2%, which is the optimal growth conditions for Enterobacter sp. B3. In an environment with a concentration of phthalic acid not exceeding 500 mg/L, Enterobacter sp. B3 has a better effect on phthalic acid degradation, and the degradation rate can reach 77% in 7 d. The results of indoor potting experiments on tobacco show that the degradation rate of phthalic acid by Enterobacter B3 in the soil is about 45%, which can reduce the inhibitory effect of phthalic acid on the growth of tobacco seedlings. This study enriches the microbial resources for degrading phthalic acid and provides a theoretical basis for alleviating tobacco continuous cropping obstacles.

Limonene’s Bacteriostatic Activity against Ralstonia solanacearum by Compromised Membrane Integrity: A Transcriptomic and Metabolomic Analysis

Ralstonia solanacearum, the causative agent of bacterial wilt, is a soil-borne pathogen that poses a widespread threat to plants in the Solanaceae family. To elucidate the mechanism by which limonene exerts its effects on R. solanacearum, we first assessed the impact of limonene on the physiological indicators of the pathogen and subsequently analyzed its transcriptome and metabolome. Our findings indicate that limonene has a potent inhibitory effect on R. solanacearum, and it also suppresses the formation of the bacterial community biofilm. Limonene primarily regulates the terpene biosynthesis pathway in R. solanacearum, thereby potentially affecting signal transduction in the pathogen and disrupting its normal growth and development. These results significantly enhance our understanding of limonene’s response to the induction of bacterial wilt and provide a reference for further prevention and control of R. solanacearum.

Geometric Accuracy and Energy Absorption Characteristics of 3D Printed Continuous Ramie Fiber Reinforced Thin-Walled Composite Structures

The application of continuous natural fibers as reinforcement in composite thin-walled structures offers a feasible approach to achieve light weight and high strength while remaining environmentally friendly.In addition,additive manufacturing technology provides a favorable process foundation for its realization.In this study,the printability and energy absorption properties of 3D printed continuous fiber reinforced thin-walled structures with different configurations were investigated.The results suggested that a low printing speed and a proper layer thickness would mitigate the printing defects within the structures.The printing geometry accuracy of the structures could be further improved by rounding the sharp corners with appropriate radii.This study successfully fabricated structures with vari-ous configurations characterized by high geometric accuracy through printing parameters optimization and path smoothing.Moreover,the compressive property and energy absorption characteristics of the structures under quasi-static axial compression were evaluated and compared.It was found that all studied thin-walled structures exhibited progressive folding deformation patterns during compression.In particular,energy absorption process was achieved through the combined damage modes of plastic deformation,fiber pullout and delamination.Furthermore,the com-parison results showed that the hexagonal structure exhibited the best energy absorption performance.The study revealed the structure-mechanical property relationship of 3D printed continuous fiber reinforced composite thin-walled structures through the analysis of multiscale failure characteristics and load response,which is valuable for broadening their applications.

Haemorrhage risk of brain arteriovenous malformation during pregnancy and puerperium

Background This study aimed to assess whether pregnancy and puerperium were associated with the risk of brain arteriovenous malformation(bAVM)haemorrhage.Methods A retrospective review was conducted in Xiangya Hospital,Central South University from January 2012 to December 2021.A case-crossover design was adopted to calculate the incidence density of bAVM-related haemorrhage among female patients in risk(pregnancy and puerperium)and control(non-pregnancy and non-puerperium)periods,according to four scenarios observed in different populations scenario I:patients with haemorrhagic bAVM of all ages;scenario II:patients with haemorrhagic bAVM of all ages,with at least one previous pregnancy;scenario III:patients with haemorrhagic bAVM who are of reproductive age(15-45 years);scenario IV:patients with haemorrhagic bAVM of reproductive age(15-45 years),with at least one previous pregnancy.Next,a comprehensive literature aggregation(up to April 2022)was performed for evidence synthesis.Results Among the 311 female patients with haemorrhagic bAVM,a significant haemorrhage risk during pregnancy and puerperium was found in Scenarios I(relative risk[RR],2.08;95%CI,1.28 to 3.39),II(RR,3.21;95%CI,1.95 to 5.31)and IV(RR,2.92;95%CI,1.73 to 4.93);however,a suggestive risk was found in scenario III(RR,1.62;95%CI,0.99 to 2.67).Evidence synthesis revealed a consistent haemorrhage risk among patients of all ages(RR,3.15;95%CI,1.93 to 5.15)and those of reproductive age(RR,1.29;95%CI,0.89 to 1.86).Conclusion Compared with most previous studies,a higher but relatively moderate risk for bAVM-related haemorrhage was identified during pregnancy and puerperium.Individualised prevention and treatment strategies should be preferred when neurosurgeons make clinical decisions.

JUNO sensitivity on proton decay p→νK^(+)searches

The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.

Feasibility and physics potential of detecting ^(8)B solar neutrinos at JUNO

The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.

Enhanced performance triboelectric nanogenerator based on porous structure C/MnO_(2)nanocomposite for energy harvesting

Triboelectric nanogenerator(TENG)can realize a variety of mechanical energy collections in the environment,which has great potential in the field of wearable energy.However,many TENGs could rarely be satisfactory to wearable electronics promotion because of their expensive raw materials and complex manufacturing processes.In this study,a type of porous structure carbon powder/manganese dioxide(C/MnO_(2))nanocomposite is introduced.The material adopts low-cost,high-yield carbon powder,can be prepared in one step through a simple,economical,and environmentally friendly hydrothermal preparation process,and has high economic practicality.Superior power generation performance was obtained by modulating the charge trapping ability and storage capacity of polydimethylsiloxane@C/MnO_(2)(PDMS@C/MnO_(2))film based on variations in the weight-loading of C/MnO_(2).The maximum output voltage of carbon powder/manganese dioxide TENG(CM-TENG)is 63 V,which is 2.1 times that of PDMS-TENG and 1.86 times that of carbon powder TENG(C-TENG)and can easily light up 53 LEDs.Furthermore,CM-TENG can convert biological motion energy into electrical signals to detect human hand movements.The CM-TENG self-powered system can successfully drive various microelectronic devices,such as electronic watches,liquid crystal displays(LCDs),and calculators.This study provides a reliable,low-cost,high-performance,and widely applicable electronic system that shows great potential in future fields such as wearable devices and micro-sensing systems.

Sub-percent precision measurement of neutrino oscillation parameters with JUNO

JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)θ_(13) oscillation parameters using reactor antineutrinos,which is one of the primary physics goals of the experiment.The sensitivities are obtained using the best knowledge available to date on the location and overburden of the experimental site,the nuclear reactors in the surrounding area and beyond,the detector response uncertainties,and the reactor antineutrino spectral shape constraints expected from the TAO satellite detector.It is found that the △m_(21)^(2) and sin^(2)θ_(12) oscillation parameters will be determined to 0.5%precision or better in six years of data collection.In the same period,the △m_(31)^(2) parameter will be determined to about 0.2%precision for each mass ordering hypothesis.The new precision represents approximately an order of magnitude improvement over existing constraints for these three parameters.