Structural characteristics of phenylboronic acid-modified astaxanthin ester and its effect on DSS-induced ulcerative colitis by blocking reactive oxygen species and maintaining intestinal homeostasis

A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical structure and physicochemical property were identified.AstaD-PBA could effectively improve the ROS quenching ability in the lipopolysaccharide(LPS)-induced RAW264.7 cell inflammation model.Then,the bioactivity of AstaD-PBA was studied by 4 zebrafish ROS-responsive infl ammatory models induced by LPS,copper(Cu^(2+)),high-fat diet,and dextran sodium sulfate(DSS).The results suggest that AstaD-PBA might have high biosafety and the best effect on ulcerative colitis(UC)induced by DSS.Furtherly,AstaDPBA significantly alleviated and treated weight loss and colonic shrinkage,inhibited infl ammatory cytokines,and maintained microbiota homeostasis to improve UC in C57BL/6J mice.Alistipes and Oscillibacter were expected to be considered UC marker fl ora according to the Metastats analysis and Pearson correlation Mantel test(P<0.01)of 16S rRNA gene sequencing data.In conclusion,AstaD-PBA has been promised to be a functional compound to improve UC and maintain intestinal microbiota homeostasis.

疏水二氧化硅粉体对高温硫化硅橡胶性能的影响

采用橡胶的混炼硫化工艺,将3种疏水性纳米粉体材料二氧化硅气凝胶、疏水气相白炭黑和疏水沉淀白炭黑加入到高温硫化硅橡胶(HTV)中,对比分析了3种纳米粉体对硅橡胶物理力学性能的影响。研究结果表明,二氧化硅气凝胶对硅橡胶的力学增强作用最为显著,气凝胶硅橡胶复合材料具有极大的拉伸强度(9.52 N/mm^2)、极大的断裂伸长率(750%)、较高的撕裂强度(33.98 kN/m)、高疏水接触角(124°)、极高的硬度(70 HA)、低磨损率(0.04 g/cm^2)和极低的导热系数(0.11 W/(m·K))。

Evaluation Procedure for Quality Consistency of Generic Nifedipine Extended-Release Tablets Based on the Impurity Profile

A procedure to evaluate the quality consistency of generic drugs based on the impurity profile and the similarity analysis methods was presented in this paper. Nifedipine extended-release tablets from six generic factories of China were used to evaluate the uniformity with the original drug in the study. The procedure includes: choice of chromatographic methods, data collection and conformity test, evaluation of intra-batch similarity of drugs, evaluation of generic drugs with the original drug and weighted similarity evaluation of generic drugs. The data were collected via high-performance liquid chromatography (HPLC), and then calculated by correlation coefficient, cosine, principal component analysis (PCA) and hierarchical clustering analysis (HCA). It is more suitable to use peak areas as the vector when calculating the similarity of impurity profile. After weighting the peak areas of the unspecified impurities in further evaluation of the generic quality, the generic level of different factories was differentiated and the best generic factory was picked out.

Fecal microbiota reveal adaptation of herbivores to the extreme environment of the Qinghai–Tibet Plateau

Background:Gut microbiota is pivotal in regulating hosts'biological processes and maintaining homeostasis,but knowledge about its role in wild herbivores in extreme environments remains limited.Methods:Gut bacteria and fungi were sequenced in ruminant(Chiru and Yak)and nonruminant(Kiang)herbivores on the Qinghai–Tibet Plateau,and their community structure,co-occurrence networks,functions,and assembly mechanisms were investigated using multivariate ecological and statistical methods.Results:Kiang had lower gut microbial diversity than Chiru and Yak.Bacterial host-specific exclusivity was greater than that of fungi.In addition to the evidence of glycan biosynthesis and carbohydrate metabolism,Chiru had a high Firmicutes/Bacteroidetes ratio and low animal pathogen abundance,suggesting better adaptation to the plateau's harsh environment.Additionally,members of gut microbiota tended to co-occur rather than co-exclude in all herbivores.Different network complexity and stability patterns were observed between bacterial and fungal communities.Furthermore,gut bacterial assembly was primarily controlled by stochastic dispersal limitation and drift,whereas fungal assembly was primarily controlled by deterministic homogeneous selection except in Chiru.Conclusions:On the Qinghai–Tibet Plateau,Chiru and Yak exhibit more diverse gut microbiota and more diverse metabolic functions than Kiang,and gut bacteria are more divergent than gut fungi in these herbivores.

Removing microplastics from aquatic environments:A critical review

As one of the typical emerging contaminants,microplastics exist widely in the environment because of their small size and recalcitrance,which has caused various ecological problems.This paper summarizes current adsorption and removal technologies of microplastics in typical aquatic environments,including natural freshwater,marine,drinking water treatment plants(DWTPs),and wastewater treatment plants(WWTPs),and includes abiotic and biotic degradation technologies as one of the removal technologies.Recently,numerous studies have shown that enrichment technologies have been widely used to remove microplastics in natural freshwater environments,DWTPs,and WWTPs.Efficient removal of microplastics via WWTPs is critical to reduce the release to the natural environment as a key connection point to prevent the transfer of microplastics from society to natural water systems.Photocatalytic technology has outstanding pre-degradation effects on microplastics,and the isolated microbial strains or enriched communities can degrade up to 50%or more of pre-processed microplastics.Thus,more research focusing on microplastic degradation could be carried out by combining physical and chemical pretreatment with subsequent microbial biodegradation.In addition,the current recovery technologies of microplastics are introduced in this review.This is incredibly challenging because of the small size and dispersibility of microplastics,and the related technologies still need further development.This paper will provide theoretical support and advice for preventing and controlling the ecological risks mediated by microplastics in the aquatic environment and share recommendations for future research on the removal and recovery of microplastics in various aquatic environments,including natural aquatic environments,DWTPs,and WWTPs.

Assessing mechanisms for microbial taxa and community dynamics using process models

Disentangling the assembly mechanisms controlling community composition,structure,distribution,functions,and dynamics is a central issue in ecology.Although various approaches have been proposed to examine community assembly mechanisms,quanti-tative characterization is challenging,particularly in microbial ecology.Here,we present a novel approach for quantitatively delineating community assembly mechanisms by combining the consumer–resource model with a neutral model in stochastic differential equations.Using time-series data from anaerobic bioreactors that target microbial 16S rRNA genes,we tested the applicability of three ecological models:the consumer–resource model,the neutral model,and the combined model.Our results revealed that model performances varied substantially as a function of population abundance and/or process conditions.The combined model performed best for abundant taxa in the treatment bioreactors where process conditions were manipulated.In contrast,the neutral model showed the best performance for rare taxa.Our analysis further indicated that immigration rates decreased with taxa abundance and com-petitions between taxa were strongly correlated with phylogeny,but within a certain phylogenetic distance only.The determinism underlying taxa and community dynamics were quantitatively assessed,showing greater determinism in the treatment bioreactors that aligned with the subsequent abnormal system functioning.Given its mechanistic basis,the framework developed here is expected to be potentially applicable beyond microbial ecology.

Spectral-furcated vector soliton in birefringence-managed fiber lasers

We demonstrate spectral-furcated vector solitons in normal-dispersion fiber lasers comprising a section of polarizationmaintaining fiber.The spectrum of each orthogonal-polarized component is confined by the birefringence-related phasematching principle,and the bicorn spectral structure corresponds to the zero-order sidebands of two vector modes.Due to the Hopf bifurcation effect,the vector soliton evolves into a breathing state at the higher pump level,accompanied by an extra set of sub-sidebands that continuously exchange energy with the zero-order sidebands.Simulation results fully reproduce experimental observations of the spectral furcation and soliton breathing,offering comprehensive insights into the pulse-shaping mechanism of the birefringence-managed soliton.

Comparative study of the pathogenicity of the mosquito origin strain and duck origin strain of Tembusu virus in ducklings and three-week-old mice

Dear Editor,Duck Tembusu virus(DTMUV)is the causative agent of a new,acute and severe infectious disease in ducks(Su et al.,2011).TMUV was first isolated from Culex tritaeniorhynchus in Malaysia in 1955(Platt et al.,1975),and this strain is regarded as a reference strain.In our previous study,an infectious clone for the mosquito-derived Tembusu virus prototypical strain MM_1775(GenBank:JX477685.2)was constructed,and the rMM_1775 virus was rescued successfully(Wang et al.,2021).And the TMUV strain rCQW1 was rescued by a reverse genetic system using the viral RNAs of CQW1(GenBank:KM233707.1)(Chen et al.,2018;Guo et al.,2020),which was isolated from ducks in 2013(Zhu et al.,2015).

Antibiotic resistome mostly relates to bacterial taxonomy along a suburban transmission chain

Antibiotic resistance genes comprising antibiotic resistome are of great concern due to their increase in the environment.Recent evidence of shared resistomes between soils and animal husbandry has imposed potential risks to human health.However,the correlation between a given community’s resistome and bacterial taxonomic composition is controversial.Here,a transmission chain of resistomes from swine manure to compost and compost-amended soil were analyzed in five suburban areas of Beijing,China,with unamended agricultural soils as control soils.Antibiotic resistomes and bacterial taxonomic compositions were distinct between(I)manure and compost;and(II)compost-amended and control soils.In manure,compost,and compost-amended soils,theβ-diversity of the resistome and bacterial taxonomic composition was significantly correlated,while no correlation was detected in control soils.Bacterial taxonomic composition explained 36.0%of total variations of the resistome composition,much higher than environmental factors.Together,those results demonstrated that antibiotic resistome was closely related to bacterial taxonomic composition along the suburban transmission chain.

Coherent dissipative soliton intermittency in ultrafast fiber lasers

As a universal phenomenon in nonlinear optical systems,intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber lasers.Based on real-time spectroscopy,we revealed the coherent dissipative soliton intermittency in normal-dispersion fiber lasers.By increasing the pump strength,the intermittency transforms from the transient pulsation to the bo-stable soliton.It is demonstrated that the slow-gain effect dominates such coherent intermittency.Our results provide novel insights into laser physics,offering a promising approach for studying the bi-stable dissipative soliton.

Birefringence-Managed Normal-Dispersion Fiber Laser Delivering Energy-Tunable Chirp-Free Solitons

Chirp-free solitons have been mainly achieved with anomalous-dispersion fiber lasers by the balance of dispersive and nonlinear effects,and the single-pulse energy is constrained within a relatively small range.Here,we report a class of chirp-free pulse in normal-dispersion erbium-doped fiber lasers,termed birefringence-managed soliton,in which the birefringence-related phasematching effect dominates the soliton evolution.Controllable harmonic mode locking from 5 order to 85 order is obtained at the same pump level of~10 mW with soliton energy fully tunable beyond ten times,which indicates a new birefringencerelated soliton energy law,which fundamentally differs from the conventional soliton energy theorem.The unique transformation behavior between birefringence-managed solitons and dissipative solitons is directly visualized via the singleshot spectroscopy.The results demonstrate a novel approach of engineering fiber birefringence to create energy-tunable chirpfree solitons in normal-dispersion regime and open new research directions in fields of optical solitons,ultrafast lasers,and theirapplications.

A novel reversible-deactivation radical polymerization strategy via near-infrared light-controlled photothermal conversion dividing wall-type heat exchanger

As an effective means of utilizing light energy,photothermal conversion has excellent application in the field of polymerization.Herein,a dividing wall-type heat exchanger with the aid of photothermal conversion was designed to conduct polymerization under irradiation with near-infrared(NIR)light by utilizing the ketocyanine-type dye solution as the highly efficient activator(>83.2%photothermal conversion efficiency).Various types of reversible-deactivation radical polymerization(RDRP)methods,including reversible addition-fragmentation chain transfer,atom transfer radical polymerization,and bromine-iodine transformation RDRP,are suitable for this strategy.Well-defined polymers with excellent control over molar mass and molar mass dispersity(D<1.28)were thus synthesized within a few hours under NIR(λ_(max)=810 nm,850 nm)irradiation at room temperature.Importantly,in addition to conventional heating methods(such as electrical heating jackets),the designed dividing wall-type heat exchanger via NIR light activation has another unique advantage:it can enhance the polymerization by the synergistic effect of both heating and NIR light irradiation due to the deeper penetration of NIR light.

Determination of cut-off time of accelerated aging test under temperature stress for LED lamps

To acquire a rational minimum cut-off time and the precision of lifetime prediction with respect to cut-off time for the accelerated aging test of LED lamps, fifth-order moving average error estimation is adopted in this paper. Eighteen LED lamps from the same batch are selected for two accelerated aging tests, with 10 samples at 80 ℃ and eight samples at 85 ℃. First, the accelerated lifetime of each lamp is acquired by exponential fitting of the lumen maintenances of the lamp for a certain cut-offtime With the acquired lifetimes of all lamps, the two-parameter Weibull distribution of the failure probability is obtained, and the medium lifetime is calculated. Then, the precision of the medium lifetime prediction for different cut-off times is obtained by moving average error estimation. It is shown that there exists a minimum cut-off time for the accelerated aging test, which can be determined by the variation of the moving average error versus the cut-offtime. When the cut-off time is less than this value, the lifetime estimation is irrational. For a given cut-off time, the precision of lifetime prediction can be computed by average error evaluation, and the error of lifetime estimation decreases gradually as the cut-off time- increases. The minimum cut-off time and medium lifetime of LED lamps are both sensitive to thermal stress. The minimum cut-off time is 1104 h with the lifetime esti- mation error of 1.15% for the test at 80 ~C, and 936 h with the lifetime estimation error of 1.24% for the test at 85 ℃. With the lifetime estimation error of about 0.46%, the median lifetimes are 7310 h and 4598 h for the tests at 80 ℃ and 85℃, respectively.