最新刊期
卷 64 ， 期 3 ， 2025
- 摘要：In this study，a total of 23 compounds were obtained from the ethyl acetate part of Triadica rotundifolia by various chromatographic methods such as silica gel，Sephadex LH20，and p-HPLC column chromatography. Their structures were identified by NMR spectroscopy combined with comparative analysis with literature data as known compounds： toddanone（1），toddalolactone（2），scopoletin（3），6，7-dimethoxycoumarin（4），6，7，8-trimethoxycoumarin（5），8-hydroxy-5，6，7-trimethoxycoumarin（6），5，6，7，8-tetramethoxycoumarin（7），lup-20（29）-ene-3α，23-diol（8），glochidone（9），3β-O-trans-caffeoylbetulinic acid（10），oleana-1，18-dien-3-one（11），morolic acid acetate（12），β-sitosterol（13），daucosterol（14），6-hydroxystigmast-4-en-3-one（15），oleodaphnone（16），5′-methoxynobiletin（17），trigonochinene E（18），ethyl gallate（19），daphnelantoxin B（20），（+）-3-hydroxy-1，5-diphenyl-l-pentanone（21），5-hydroxy-3，4-dimethyl-5-pentylfuran-2（5H）-one（22），and indole-3-carbaldehyde（23）. Compounds 1-23 were isolated from T. rotundifolia for the first time. In addition，activity screening revealed that compounds 8 and 18 showed moderate cytotoxicity to H1975 cells，with IC50 values of （13.97 ± 0.40） μmol/L and （26.61 ± 1.81） μmol/L，respectively.关键词：Triadica rotundifolia;chemical constituents;cytotoxicity178|112|0更新时间：2025-11-14
- 摘要：Nine known aromatic compounds （1-9） were isolated from the ethyl acetate extracts of the solid cultures of marie-derived fungus Penicillium rolfsii 8196#， isolated from sponge xestospongia sp.. Their structures were elucidated by spectroscopic analysis and comparative investigation with references. These compounds were evaluated for their cytotoxic， antibacterial and antioxidant activities. Among them， Compound 6 showed cytotoxicity against human bladder cancer T-24 cells with the IC50 values of 16.60 μmol/L， compounds 4 and 5 exhibited weak inhibitory effects against Salmonella with MIC values of 50 μmol/L， and compounds 8 and 9 showed the free radical scavenging rate 79.81% and 70.84% at the concentration of 10 μmol/L， respectively.关键词：marine-derived fungus;Penicillium sp.;secondary metabolites150|125|0更新时间：2025-11-14
- 摘要：The secondary metabolites of the rice fermentation of Aspergillus versicolor NJF3， a fungus derived from the surface seawater of the South China Sea， were investigated in this study. The rice solid fermentation product of this strain was extracted with 95% ethanol and subjected to ethyl acetate extraction， followed by repeated chromatographic separation and purification. As a result， a total of 15 compounds were obtained， and their structures were identified by spectral data analysis as meleagrin （1）， fumigaclavine C （2）， cyclo（L-Trp-L-Phe） （3）， phenazine-1-carboxylic acid （4）， phenazine-1-carboxamide （5），N-（2-hydroxypropanoyl）-2-aminobenzoic acid amide （6）， orlandin （7）， monomethylsulochrin （8）， sydowinin A （9）， diorcinol-3-O-α-D-ribofuranoside （10）， cordyol C-3-O-α-D-ribofuranoside （11）， 3，3'-dihydroxy-5，5'-dimethyldiphenyl ether （12）， 3，5-dihydroxytoluene （13）， 3，7-dihydroxy-1，9-dimethyldibenzofuran （14）， and p-hydroxyphenylacetic acid methyl ester （15）， respectively. All compounds were known structures， among them diphenyl ether glycosides 10 and 11 were isolated from secondary metabolites of A. variegatus for the first time. In addition， activity screening showed that compound 1 moderate cytotoxicity to NSCLC cells.关键词：marine fungi;secondary metabolites;Aspergillus;cytotoxicity207|137|0更新时间：2025-11-14
- 摘要：Based on α-mangostin as the lead compound， and using the primary methods including alkylation and hydrolysis reactions for modifying C-3 and C-6 positions， eighteen novel derivatives with different chain length of carboxylic acid ester， carboxylic acid， and amide substituents in the C-3， C-6 phenolic hydroxyl group of α-mangostin were designed and synthesized. The in vitro evaluation of these compounds' ability to inhibit PDE4 was conducted using the ［³H］ liquid scintillation counting technique. The experimental results showed that five compound （2a-6a） had the stronger inhibitory activity on PDE4 than α-mangostin. Among them， carboxylic acid derivative of seven carbon chain lengths 5a exhibited the best potential PDE4 inhibitory activity with the IC50 values of 319 nmol/L.关键词：α-mangostin;derivatives;phosphodiesterase 4（PDE4）101|46|0更新时间：2025-11-14
- 摘要：To study the chemical constituents of the Eucalyptus tereticornis and explore their potential biological activity， a total of 21 compounds were obtained from the petroleum ether and ethyl acetate part of the ethanol extract of Eucalyptus tereticornis by silica gel column chromatography， Sephadex LH-20 column chromatography， and semi-preparative high performance liquid chromatography （HPLC）. By the analysis of NMR，ESI-MS， and specific rotation values combined with comparative analysis with literature data， the structures of compounds were identified as ten lignans： Ehletianol C（1）， dihydrobuddlenol B（2）， dehydrodiconiferyl alcohol（3）， herpetin （4）， vitrifol A（5）， （-）-syringaresinol （6）， （-）-lyoniresinol （7）， （-）-isolariciresinol （8）， erythro-1-（3，4-dimethoxyphenyl）-2-O-（2-methoxy-4-omegahydroxypropylphenyl）propane-1，3-diol （9）， and threo-guaiacylglycerol-β-O-4′-dihydroconiferyl alcohol （10）； three phloroglucinols： multifidol glucoside （11）， lysidiside A （12）， and 2，4，6-trihydroxy-1-butyrophenone-2-O-β-D-glucopyranoside （13）； three flavones： （S）-naringenin 7-O-glycoside （14）， （-）-2，3-trans-dihydrokeampferol-3-O-α-L-rhamnoside（15）， and phloretin （16）； and five aryl C-glycosides： garcimangosone D（17）， deoxyrhaponticin （18）， glochierioside F（19）， citrusin C（20）， and benzyl β-D-glucopyranoside （21）. All the compounds were separated from Eucalyptus tereticornis for the first time， and compounds 1，2，4，5，19， and 20 were separated from the genus Eucalyptus for the first time. The in vitro antioxidant activity of compounds was evaluated by using DPPH method. The results indicated that compounds 1， 4，6，7，9，10，12，13，15， and 16 exhibited certain activity， with IC50 values ranging from 13.42-65.97 μg/mL， weaker than vitamin C. Among them， compounds 3，6， and 10 showed significant antioxidant activity， comparable to vitamin C.关键词：Eucalyptus tereticornis;phloroglucin;flavanonols;lignans;chemical constituents145|48|0更新时间：2025-11-14
Column of natural products chemistry
- 摘要：Thrombopoietin （TPO） regulates the development of megakaryocytes and the production of platelets through its receptor c-Mpl， and has a negative correlation with the prognosis and survival of various tumors， which is related to the internalization and degradation of circulating TPO and the endocytosis of the c-Mpl splice variant c-Mpl-D. This study constructed a UT-7/c-Mpl-D stable cell line using a reverse transcription expression system to study the function of c-Mpl-D in isolation. A Dami/c-Mpl-D stable cell line was also constructed by electroporation to investigate the regulatory effect of c-Mpl-D on c-Mpl-F function. Further， the interaction between c-Mpl-D and TPO was studied using crosslinking and immunoprecipitation. The results indicated that， when coexisting with c-Mpl-F， c-Mpl-D can promote Dami cell proliferation， inhibit Dami cell apoptosis， and prevent Dami cells from maturing towards megakaryocytes. Additionally， c-Mpl-D significantly reduced the receptor internalization effect after TPO stimulation. In summary， this study proposes a model related to the physiological significance of the increasing expression of c-Mpl-D with the differentiation and maturation of megakaryocytes， providing new insights into the relationship between c-Mpl-D and the proliferation and differentiation of megakaryocytes. It offers new experimental evidences for the analysis of the mechanisms of megakaryocyte proliferation and differentiation， and promotes the prevention， diagnosis， and treatment of c-Mpl-D-related diseases.关键词：c-Mpl-D;megakaryocytes;proliferation;differentiation;internalization122|97|0更新时间：2025-11-14
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A dual-emission carbon dots-based ratiometric sensor for detection and cellular imaging of Mn2+ ions
摘要：Manganese (Mn), an essential trace element in the human body, plays critical roles in many biological processes. Recent studies have discovered that Mn2+ may promote or directly activate the cGAS-STING pathway, thereby subsequently initiating the natural immune response and augmenting antitumor therapy. However, the current lack of accurate methods for Mn2+ determination in cells significantly limits their mechanism investigation; hence, it is urgent to establish novel tools to detect Mn2+ in cells. In this study, the dual-emission carbon dots were initially synthesized via the one-pot hydrothermal method employing L-aspartic acid and p-phenylenediamine as raw materials. In the presence of Mn2+, the emission peak centered at 350 nm exhibited significant enhancement, whereas another peak at 610 nm remained stable. Consequently, a ratiometric sensor for Mn2+ determination was established using the signal at 350 nm as the responsive signal and the signal at 610 nm as an internal reference. Under the optimal condition, a good linear relationship was achieved between the F350/F610 value and Mn2+ concentration ranging from 0.9 to 15 μmol/L, with a calculated LOD of 61 nmol/L. Benefiting from the special Mn2+-induced ratiometric approach, this method demonstrates outstanding sensitivity, selectivity, and stability, rendering it applicable for Mn2+ determination in complex biological samples, as well as Mn2+ imaging in MKN-45 and LO2 cells.关键词：Mn2+;carbon dots;ratiometric;cell imaging;fluorescence87|47|0更新时间：2025-11-14 - 摘要：The proliferation of water hyacinth poses serious threats to regional water security and ecological balance. Timely and accurate monitoring of the distribution of water hyacinth is fundamental to its management. To enhance the efficiency，accuracy，and applicability of remote sensing monitoring for water hyacinth，this study proposes a remote sensing monitoring method based on the spatiotemporal relationships of land cover. This method extracts the vegetation range and eliminates the influence of terrestrial vegetation by calculating and comparing the changes in the spectral index relationships of vegetation and water bodies in long-term optical remote sensing images，thereby enabling the rapid extraction of water hyacinth pixels. The effectiveness of this method is validated in the Jianjiang River Basin，and the distribution characteristics of water hyacinth in the basin for the year 2022 are analyzed. The results indicate that this method performs well in identifying water hyacinth，achieving an accuracy of 92.9% and a recall rate of 86.7%. From March to May in 2022，several high-density aggregation areas of water hyacinth were observed in the main rivers of the Jianjiang River Basin，with the overall area of water hyacinth showing a trend of initial increasing and then decreasing. This method provides valuble technical support for the accurate monitoring and precise control of large-scale water hyacinth.关键词：water hyacinth;remote sensing;spectral index;Sentinel112|82|0更新时间：2025-11-14
- 摘要：Green space is recognized as a crucial factor in promoting health and sustainable development， as it provides ecological， social， and economic benefits to a region. Various regional climates， social and economic conditions， and spatial aggregation types of green space exhibit distinct differences， leading to variations in the service levels of green areas. Focusing on climate and socio-economic factors， a bivariate spatial autocorrelation analysis was conducted to investigate the spatial aggregation characteristics and service level of green space at the district and county scale in Guangdong Province in 2020. The results indicate that green space and its associated indices display a continuous “high-low” aggregation pattern in certain districts and counties within the core of Pearl River Delta and East Guangdong. Conversely， the “low-high” banded clusters are primarily distributed in northern Guangdong. Among the four regions analyzed， northern Guangdong boasts a high level of green space service that adequately meets the climate and socio-economic needs. In contrast， the Pearl River Delta and eastern Guangdong region exhibit lower service levels of green space， highlighting prominent inequalities of climate， social， and economic factors. The results reflect the varying service levels and the supply-demand relationships of green space in each district of Guangdong Province and provide scientific guidance for further urban green space planning and development.关键词：green space;bivariate spatial autocorrelation;Moran index;service level122|88|0更新时间：2025-11-14
- 摘要：Understanding the mechanical properties of loess under extreme dry-wet alternating climatic conditions is essential for analyzing and evaluating the stability of geological bodies. Focusing on the Q3 loess of a cutting slope in the Yan'an new area， we conducted repeated dry-wet cycle tests and direct shear tests of undisturbed and remolded loess to investigate how factors， such as dry-wet cycles， cycling path， amplitude， and normal pressure， affect loess' shear strength and its associated properties. The results indicate that the relationship curve between shear stress and shear displacement for dry-wet cycle loess， under different normal pressures， exhibits a strain-softening behavior； Furthermore， the peak characteristics of the curve gradually diminish as the number of dry-wet cycles increases. The shear strength attenuation of undisturbed loess during dry-wet cycles is more pronounced than that of remolded loess， with shear strength decreasing by 77.82% after three dry-wet cycles. Significant differences exist in both shear strength and its parameters in dry-wet cycle loess across high- and low-pressure conditions， with the low-pressure condition requiring careful consideration in direct shear tests. The shear strength parameter of loess declines rapidly with the increasing number of dry-wet cycles initially， then decreases slowly before stabilizing. Notably， the impact of dry-wet cycles on cohesion is greater than that on internal friction angle. Additionally， the shear strength parameter of loess is negatively correlated with the amplitude of dry-wet cycles， cohesion in high-pressure conditions and internal friction angle in low-pressure conditions showed more significant deterioration at larger dry-wet cycle amplitudes. The evolution of the deterioration curve for the loess shear strength parameter can be divided into three stages： a rapid growth stage （1-3 times）， a slow growth stage （3-5 times）， and a gradual stability stage （5-7 times）， with over 78.77% occurring during the rapid growth stage. Based on the statistical analysis of the experimental data， we have established a predictive model for the absolute deterioration degree of cohesion and internal friction angle in dry-wet cycle loess.关键词：cutting slope;shallow loess;extreme dry-wet alternating;shear strength;deterioration model170|106|0更新时间：2025-11-14
- 摘要：Two-dimensional ferroelectric α-In2Se3 was fabricated using the mechanical exfoliation method， and the structural characteristics of the samples were analyzed by atomic force microscopy （AFM）. Ferroelectric channel transistors with α-In2Se3 as the channel were prepared by electron beam lithography. This work reveals that the out-of-plane polarization of α-In2Se3 can be effectively modulated by applying electrical pulses to the top-gate electrode， enabling the short-term plasticity （STP） through synaptic potentiation and depression. Significantly， cumulative gate voltage pulses amplify the ferroelectric polarization in the channel via domain alignment dynamics， resulting in a progressive enhancement of synaptic current， which facilitates transition from STP to long-term plasticity（LTP）. Furthermore， the tunable LTP characteristics modified by pulse amplitude engineering demonstrate the capability of α-In2Se3 device to emulate complex synaptic learning rules.关键词：mechanical exfoliation;two-dimensional ferroelectric α-In2Se3;out-of-plane ferroelectricity;ferroelectric channel transistors;synaptic transistors133|51|0更新时间：2025-11-14
- 摘要：In response to the potential failure of global positioning systems in disaster environments and the degradation of visible light images， as well as the low success rate of traditional computer vision-based relocalization algorithms due to insufficient image feature points， a semantic map-based drone relocalization method for unmanned aerial vehicle（UAV） is proposed. This method relies on RGB-D images to identify and construct landmark points in the disaster-affected environment. These landmark points are then matched with prior maps to optimize and estimate the relative pose of the drone. By reducing the suppression of the potential general object recognition capability within object recognition networks， high-level feature points in the image are obtained， effectively addressing the problem of difficult relocalization due to insufficient feature points. Building on the generalized object-based reconstruction of landmark points， an efficient method for retrieving and matching these points is proposed. Experimental results demonstrate that the approach can reconstruct a richer set of landmarks in unknown environments and effectively utilize them for localization， compared to other object recognition-based landmark point construction methods. In disaster scenarios with image degradation， this method exhibits higher recall rates and robustness than widely used image retrieval methods.关键词：urban fire;UAV;relocalization;semantic map;loop closure detection97|89|0更新时间：2025-11-14
- 摘要：A fog concentration evaluation algorithm based on logistic function fitting S-type scatter plot was proposed. Firstly， a scatter-plot prior of normalized gray difference-ratio（NGDR） from the standard LIVE image set was extracted，and Logistic functions was introduced to derive a regression analysis model based on the one-to-one correspondence between the scatter curve and the fog concentration. Secondly， the iterative search method was used to determine the optimal sample points of longitudinal Gaussian distribution to improve the detection accuracy. Finally， a lookup table for parameter estimation（
- 摘要：Highway transaction data were utilized to select 10 indicators representing user-specific characteristics and the spatiotemporal features of travel，forming the basis for constructing a user characteristic model. To classify highway user characteristics，the K-means，fuzzy C-means，and self-organizing map algorithms were applied to ETC data from a specific road segment. The results indicate that，compared to K-means and fuzzy C-means，the SOM model performs better in classifying user travel patterns and supports the reasonable classification of highway users into six categories. Based on these classification results，a personalized differential tolling strategy is proposed，and its feasibility is validated through numerical simulation.关键词：ETC data;clustering algorithm;travel mode analysis;differentiated charges116|83|0更新时间：2025-11-14
- 摘要：Based on a deep foundation pit project in Wuhan，we establishe a numerical model using the PLAXIS 2D， analyze the sensitivity of HSS model parameters for cohesive and sandy soils， evaluate the sensitivity of soft soil layers in the first terrace of the Yangtze River， and invert the significantly sensitive parameters. Firstly， the sensitivity analysis of certain parameters of the HSS model for cohesive and sandy soils is conducted， focusing on the parameters that most significantly affect the settlement of the tunnel crown. Then， the sensitivity analysis of the soft soil layers in the first terrace of the Yangtze River is carried out to determine the soil mechanical parameters to be inverted. Finally， combining the existing tunnel crown settlement monitoring data， the inversion of the soil mechanical parameters to be inverted is conducted using a deterministic forward-inverse method.The results show that for both cohesive and sandy soils， the parameter that most significantly affects the tunnel crown settlement is the small-strain reference initial shear modulus（G
- 摘要：The performance of the solar UAV propeller under the improved installed condition is studied. Firstly， wind tunnel test is carried out to verify the accuracy of the numerical simulation method choosed in this paper in the case of the installation of a separate propeller. Secondly， the effects of the propeller installation position， the individual propeller and the winged propeller on the performance of the propeller were calculated by using the constant and unsteady numerical simulation methods， and the influence of the improved propeller on the performance of the UAV was calculated. The results show that the winged propeller causes the propeller thrust and power to increase， and the propeller slipstream has little effect on the nacelle， mainly due to the acceleration of the slipstream leading to a slight increase in drag. Propeller slipstream results in lower UAV wing lift curve slope， higher drag and higher pitch stability. As the distance between the propeller and the leading edge of the wing increases， the performance of the winged propeller gradually approaches that of the propeller without the wing.关键词：solar UAV;aerodynamic performance;the individual propeller;the winged propeller;propeller slipstream;numerical simulation86|95|0更新时间：2025-11-14
- 摘要：In the absence of additional auxiliary tests and relying solely on histopathological images，small-volume biopsy samples of retroperitoneal soft tissue tumors often lead to interobserver variability，impacting the overall diagnostic accuracy of disease subtypes. To address this issue，157 whole-slide images（WSIs） were collected from multiple centers，encompassing five disease categories： dedifferentiated liposarcoma（DDLP），leiomyosarcoma（LMS），malignant peripheral nerve sheath tumor（MPNST），undifferentiated pleomorphic sarcoma（UPS），and well-differentiated liposarcoma（WDLP）. Based on these WSIs， two model ensemble methods were proposed： one based on single-scale images and the other on multi-scale images. Deep learning models，such as ResNet18，EfficientNet B7，and EfficientNet V2，were trained on the collected data. Results showed that both ensemble methods achieved high classification accuracy，with the best model achieving an overall accuracy of 82.27% in patch-level analysis and 80.95% in WSI-level analysis. Therefore，the proposed methods can effectively assist pathologists in the clinical diagnosis of retroperitoneal soft tissue tumors.关键词：retroperitoneal soft tissue sarcomas;deep learning;whole slide images;subtyping141|118|0更新时间：2025-11-14
- 摘要：We study the quantum integrable system of type
- 摘要：This paper explores the recovery of block sparse signals in frame-based settings using the
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