This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,an...This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,and aldehydes,alcohols,and esters were the main volatile compound categories.There were 11 key volatile compounds,including geraniol,benzeneacetaldehyde,methyl salicylate,linalool,etc.contributed to distinguishing the tea stems from the tea leaves.In the quantitative and liquid chromatography-mass spectrometry(LC-MS)-based metabolomics analysis,higher contents of amino acids,monosaccharides,and quinic acids were found in stems than those in leaves.Inversely,higher contents of tea pigments,flavan-3-ols,gallic acid,purine alkaloids,and flavonol glycosides were present in tea leaves than in stems.LC-MS-based metabolomics also revealed that organic acids were the most critical non-volatile compounds responsible for the differences between tea stems and leaves.Furthermore,tea stems had better inhibiting effects of pro-inflammatory cytokines(interleukin(IL)-1βand IL-6)in lipopolysaccharide-challenged RAW264.7 macrophages than tea leaves,while no significant differences exist between leaves and stems for inhibiting the secretion of tumor necrosis factorα(TNF-α)and NO.In conclusion,our results support using Keemun black tea stems as a novel source of anti-inflammatory compounds.展开更多
With the continuous advancement of artificial intelligence(AI)technology,personalized learning systems are increasingly applied in higher education.Particularly within STEM(Science,Technology,Engineering,and Mathemati...With the continuous advancement of artificial intelligence(AI)technology,personalized learning systems are increasingly applied in higher education.Particularly within STEM(Science,Technology,Engineering,and Mathematics)education,AI demonstrates significant advantages through adaptive learning pathways,instant feedback,and individualized resource allocation.However,current research predominantly focuses on the technical architecture and application effectiveness of such systems,with insufficient exploration of how AI-enabled personalized learning systems influence university students’learning motivation and academic achievement through educational psychological mechanisms.This paper adopts an educational psychology perspective to construct a causal mechanism model linking“learning motivation-learning behavior-academic achievement.”Findings indicate that AI-powered personalized learning systems enhance learning autonomy,boost self-efficacy,and optimize feedback mechanisms.These effects collectively stimulate university students’learning motivation in STEM disciplines,thereby promoting academic achievement.Building upon empirical research,this paper proposes implications for educational practice and policy formulation,emphasizing the necessity of advancing higher education reform through the dual influence of technology and psychological mechanisms.展开更多
Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-li...Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.展开更多
To investigate the differences in physical and chemical indicators of tobacco stems from different parts of the‘Honghuadajinyuan’variety in the Dali tobacco-growing area,a comparative analysis of these indicators wa...To investigate the differences in physical and chemical indicators of tobacco stems from different parts of the‘Honghuadajinyuan’variety in the Dali tobacco-growing area,a comparative analysis of these indicators was conducted.The results showed that in terms of physical indicators,the tobacco stem length and content in middle part were significantly higher than those in other parts;the filling value of cut stems in upper part was significantly better than that in the middle and lower parts.In terms of chemical compositions,the content of total sugar and reducing sugar in middle part were the highest;the content of nicotine,total chlorine,and chlorine in upper part were the highest;the difference between total sugar and reducing sugar,sugar-to-nicotine ratio,nitrogen-to-nicotine ratio,and potassium-to-chlorine ratio in middle part were the best;and the potassium content in lower part was significantly higher than that in other parts.Correlation analysis showed that equilibrium moisture content was significantly positively correlated with total nitrogen content.Among them,equilibrium moisture content in upper part was positively correlated with nicotine content,and equilibrium moisture content in middle part was positively correlated with potassium and chlorine content.In addition,the filling value of cut stems in lower part was positively correlated with reducing sugar and total nitrogen content,while the filling value of cut stems in all parts was negatively correlated with the difference between total sugar and reducing sugar,sugar-to-nicotine ratio,and nitrogen-to-nicotine ratio.展开更多
All plant organs are derived from stem cell-containing meristems.In maize,the shoot apical meristem(SAM)is responsible for generating all above-ground structures,including the male and female inflorescence meristems(I...All plant organs are derived from stem cell-containing meristems.In maize,the shoot apical meristem(SAM)is responsible for generating all above-ground structures,including the male and female inflorescence meristems(IMs),which give rise to tassel and ear,respectively.Forward and reverse genetic studies on maize meristem mutants have driven forward our fundamental understanding of meristem maintenance and differentiation mechanisms.However,the high genetic redundancy of the maize genome has impeded progress in functional genomics.This review comprehensively summarizes recent advancements in understanding maize meristem development,with a focus on the integration of single-cell and spatial technologies.We discuss the mechanisms governing stem cell maintenance and differentiation in SAM and IM,emphasizing the roles of gene regulatory networks,hormonal pathways,and cellular omics insights into stress responses and adaptation.Future directions include cross-species comparisons,multi-omics integration,and the application of these technologies to precision breeding and stress adaptation research,with the ultimate goal of translating our understanding of meristem into the development of higher yield varieties.展开更多
[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by...[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.展开更多
Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ<sub>1-42</sub>-induced oligodendrocytes (OL) damage. ...Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ<sub>1-42</sub>-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ<sub>1-42</sub>, an injury model was established by subjecting OLN-93 cells to Aβ<sub>1-42</sub> exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ<sub>1-42</sub>. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ<sub>1-42</sub>-induced damage of OL.展开更多
In this study, 8 kinds of desiccation models and 3 kinds of collection models were studied for banana stems. The results showed that the crushing-com- pression-air drying processing model showed the best desiccation e...In this study, 8 kinds of desiccation models and 3 kinds of collection models were studied for banana stems. The results showed that the crushing-com- pression-air drying processing model showed the best desiccation effect for banana stems. Under this desiccation model, the moisture content was reduced from 90.5% to 19.93% with weight reduced by 75.2%; after 3 to 6 months of storage, the mois- ture content was still remained within 17%-20%, and the volume was decreased to 30%-40% of the original volume of fresh banana stems. This desiccation model made banana stems basically meet the requirements by drying storage. The plant- cutting down-crushing-compression-transportation-desiccation-storage production model was initially developed for desiccation and collection of banana stems, which would lay a certain foundation for the utilization of banana stem resource by enterprises.展开更多
[Objective] This study aimed to study the pharmacognostical properties of medicinal parts of stems and leaves of Viburnum Sargenti Koehne to provide refer- ence for its identification and application. [Method] Methods...[Objective] This study aimed to study the pharmacognostical properties of medicinal parts of stems and leaves of Viburnum Sargenti Koehne to provide refer- ence for its identification and application. [Method] Methods of characters and micro- scopic identification were used. [Result] Characters, transaction and microscopic characteristics of stems and leaves of V. sargenti Koehne were analyzed systemati- cally. [Conclusion] The experimental results can provide reference for the pharma- cognostical identification, further exploitation and utilization of stems and leaves of V. Sargenti Koehne.展开更多
Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first mor- phological indication of trichome development is an increase in nuclear content resulting from an initial cycle of...Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first mor- phological indication of trichome development is an increase in nuclear content resulting from an initial cycle of endoreduplication. Our previous study has shown that the C2H2 zinc finger protein GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome initiation in the inflorescence organ and for trichome branching in response to gibberellic acid signaling, although GIS gene does not play a direct role in regulating trichome cell division. Here, we describe a novel role of GIS, controlling trichome cell division indirectly by interacting genetically with a key endoreduplication regulator SIAMESE (SIM). Our molecular and genetic studies have shown that GIS might indireclty control cell division and trichome branching by acting downstream of SIM. A loss of function mutation of SIM signficantly reduced the expression of GIS. Futhermore, the overexpression of GIS rescued the trichome cluster cell phenotypes of sim mutant. The gain or loss of function of GIS had no significant effect on the expression of SIM. These results suggest that GIS may play an indirect role in regulating trichome cell division by genetically interacting with SIM.展开更多
Cancer stem cells(CSCs)are tumor cells that share functional characteristics with normal and embryonic stem cells.CSCs have increased tumor-initiating capacity and metastatic potential and lower sensitivity to chemo-a...Cancer stem cells(CSCs)are tumor cells that share functional characteristics with normal and embryonic stem cells.CSCs have increased tumor-initiating capacity and metastatic potential and lower sensitivity to chemo-and radiotherapy,with important roles in tumor progression and the response to therapy.Thus,a current goal of cancer research is to eliminate CSCs,necessitating an adequate phenotypic and functional characterization of CSCs.Strategies have been developed to identify,enrich,and track CSCs,many of which distinguish CSCs by evaluating the expression of surface markers,the initiation of specific signaling pathways,and the activation of master transcription factors that control stemness in normal cells.We review and discuss the use of reporter gene systems for identifying CSCs.Reporters that are under the control of aldehyde dehydrogenase 1A1,CD133,Notch,Nanog homeobox,Sex-determining region Y-box 2,and POU class 5 homeobox can be used to identify CSCs in many tumor types,track cells in real time,and screen for drugs.Thus,reporter gene systems,in combination with in vitro and in vivo functional assays,can assess changes in the CSCs pool.We present relevant examples of these systems in the evaluation of experimental CSCs-targeting therapeutics,demonstrating their value in CSCs research.展开更多
The complication of diabetes,which is known as diabetic foot ulcer(DFU),is a significant concern due to its association with high rates of disability and mortality.It not only severely affects patients’quality of lif...The complication of diabetes,which is known as diabetic foot ulcer(DFU),is a significant concern due to its association with high rates of disability and mortality.It not only severely affects patients’quality of life,but also imposes a substantial burden on the healthcare system.In spite of efforts made in clinical practice,treating DFU remains a challenging task.While mesenchymal stem cell(MSC)therapy has been extensively studied in treating DFU,the current efficacy of DFU healing using this method is still inadequate.However,in recent years,several MSCs-based drug delivery systems have emerged,which have shown to increase the efficacy of MSC therapy,especially in treating DFU.This review summarized the application of diverse MSCs-based drug delivery systems in treating DFU and suggested potential prospects for the future research.展开更多
The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With ...The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With the extensive application of S.baicalensis Georgi roots,the resource of S.baicalensis Georgi has been increasingly short.The above-ground part of stems and leaves of S.baicalensis Georgi has also been gradually recognized and developed.Studies have found that the chemical constituents from stems and leaves of S.baicalensis Georgi are also a group of flavonoids with a lot of pharmacological activity and have a great application value.Based on this,the present review will be reported on the chemical constituents and application of the roots,stems and leaves of S.baicalensis Georgi.展开更多
Biomass activated carbon(BAC)was produced from ginger stems by carbonization and activation presented high specific surface areas and mesoporous structures.The carbonization temperature of the ginger stems were contro...Biomass activated carbon(BAC)was produced from ginger stems by carbonization and activation presented high specific surface areas and mesoporous structures.The carbonization temperature of the ginger stems were controlled within 500~900℃.The optimal carbonization condition is as follows:carbonization temperature of 700℃,carbonization time of 6 h.The determined optimum activation condition is:temperature of 800℃,activator of KOH and carbonized product/alkali ratio of 1:4(w/w).The carbonization yield,BAC yield and Brunauer-Emmett-Teller(BET)surface area were measured and the adsorption performance of BAC to nitrogen was investigated.The results showed that the nitrogen adsorption isotherm curve was as type I isotherm.It was finally determined that the BET surface area was 660 m2/g under the abovementioned optimal conditions of carbonization and activation.The FESEM analysis indicates that the obtained BAC is of micropore structure.展开更多
[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to prov...[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS＋NAA 0.02 mg/L＋6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS＋NAA 0.02 mg/L＋6-BA 0.60 mg/L＋AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS＋NAA 0.40 mg/L＋IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.展开更多
Objective:To establish the standardization parameters for complete pharmacoguoslic evaluation of stems of Tlespesia lampas(T.lampas)(Cav.) Dalz & Gibs(Malvaceae),an important planl in the Indian system of medicine...Objective:To establish the standardization parameters for complete pharmacoguoslic evaluation of stems of Tlespesia lampas(T.lampas)(Cav.) Dalz & Gibs(Malvaceae),an important planl in the Indian system of medicine.Methods:Morphological,microscopical,physico-chemical evaluations,florescence analysis of T.lampas stems were investigated and preliminary phytochemical analysis,GO-MS analysis and HPTLC fingerprinting were carried out for qualitative phytochemical evaluation of various extracts of stems of T.lampas.Results:Chemomieroscopy revealed the presence of lignin.starch grains and calcium oxalate crystals.Physicochemical evaluation used to detennine numerical slandards showed a result with total ash(9.03± 0.05)%w/w,acid insoluble ash(1.50±0.01)%w/w,water soluble ash(2.51±0.02)%w/w,sulphated ash(7.50+0.01)%w/w,ethanol soluble extractive(0.24±0.02)%w/w,water soluble extractive(0.08 ±0.01)<7,w/w,moisture content(6.03±0.05)%w/w and total crude fibre content of stem powder(47.36±0.32)%w/w.Behavior characteristics of the stem powder showed presence of steroids, starch,alkaloid,flavonoids and proteins.Preliminary phytochemical analysis revealed presence of glycosides,phenolic compounds,tannins,steroids,saponins,flavonoids,carbohydrates and proteins.GC-MS analysis showed the presence of fatty acids such as dodecanoic acid, lelraclecanoic acid,n-hexadecanoic acid,9-lelradecenal and HPTLC fingerprinting revealed the presence of β-sitosterol and quercetin in stems of T.lampas.Conclusions:The pharmacognostic standardization of T.lampas is useful towards establishing standards for quality, purity and sample identification.展开更多
Owing to the potential for intercell cochannel interference mitigation and significant spectral efficiency improvement, coordinating transmission techniques by multiple radio access points have recently attracted a lo...Owing to the potential for intercell cochannel interference mitigation and significant spectral efficiency improvement, coordinating transmission techniques by multiple radio access points have recently attracted a lot of attention. In this paper, the system structure and mathematical signal model based on clustered structure are presented for multipoint coordinating downlink transmission, the clustered supercell configurations with static/dynamic approaches are discussed, and then optimal precod- ing design is provided for an accepted level of scheduling complexity and reduced signaling over- head. Some simulation results are given to evaluate the performance of different cell-clustering approaches, and to show that a clustered supercell size of 7 is a reasonable choice for clustered coordination with the given transmit power and the reduced feedback.展开更多
a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside o...a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of spectral analysis and chemical evidence.展开更多
In order to extract solanesol from potato stems and leaves more effectively and improve the extraction rate of solanesol, the same batch of potato stems and leaves harvested from Guyuan, Ningxia was selected as a rese...In order to extract solanesol from potato stems and leaves more effectively and improve the extraction rate of solanesol, the same batch of potato stems and leaves harvested from Guyuan, Ningxia was selected as a research object, cell wall of potato stems and leaves was broken by enzymolysis with cellulase and high- speed shearing, and then reflux-extracted with 95% ethanol. Solanesol content was determined by HPLC, and extract yield was calculated. Extract yield and solanesol extraction rate was used as an index for comparison of difference between the 2 wall-breaking methods, so as to select the optimal wall-breaking method. The results showed that enzymolysis with cellulase exhibited extraction rate and extract yield of solanesol of 91.38% and 8.02%, respectively, which were better than those under high-speed shear emulsification technique. The enzymolysis wall-breaking method has the advantages of simple operation and strong feasibility.展开更多
Objective:The protective effect of Scutellaria baicalensis Stems and Polygonum Cuspidatum compatibility on lipopolysaccharide(LPS)-induced acute lung injury(ALI)in rats was studied by observing the expression of TRPV1...Objective:The protective effect of Scutellaria baicalensis Stems and Polygonum Cuspidatum compatibility on lipopolysaccharide(LPS)-induced acute lung injury(ALI)in rats was studied by observing the expression of TRPV1 and inflammatory cytokines.Methods:48 male SD rats were randomly divided into 6 groups:control group,model group,dexamethasone group(5mg/kg)and Scutellaria baicalensis Stems-Polygonum Cuspidatum(3.5,7 and 14g/kg).The administration group was gavaged for 7 days,and the control group and model group were given the same amount of 0.9%sodium chloride.On the 8th day,except the control group,rats in other groups were injected with 8mg/kg LPS through caudal vein to induce Ali model.Take the rat lung tissue 6 hours after modeling,and calculate the wet/dry weight ratio(W/D)of the rat lung tissue;HE staining to observe the pathological changes of lung tissue;Determine the content of tumor necrosis factor-α(TNF-α)and interleukin-1β(1L-1β)in alveolar lavage fluid(BALF)and the activity of superoxide dismutase(SOD)in serum;Detect the mRNA and protein expression levels of TRPV1 receptor in rat lung tissue.Results:Compared with the model group,Scutellaria baicalensis Stems-Polygonum Cuspidatum can significantly reduce the damage of lung tissue structure and bleeding state,W/D value and TNF-α、IL-1βThe content of TRPV1 decreased,the level of SOD increased,and the mRNA and protein expression of TRPV1 receptor decreased.Conclusion:The combination of Scutellaria baicalensis Stems-Polygonum has a protective effect on acute lung injury in rats,and its mechanism may be related to down-regulating the expression of TRPV1 and inhibiting the levels of TNF-αand IL-1βin inflammatory cells.展开更多
基金supported by the Natural Science Foundation of China(32122079,32072633)Earmarked Fund for China Agriculture Research System(CARS-19)+2 种基金Anhui Key Research and Development Plan(202104b11020001)Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)High-level Introduced Talent Sponsorship Program by Anhui Agricultural University(rc352203)。
文摘This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,and aldehydes,alcohols,and esters were the main volatile compound categories.There were 11 key volatile compounds,including geraniol,benzeneacetaldehyde,methyl salicylate,linalool,etc.contributed to distinguishing the tea stems from the tea leaves.In the quantitative and liquid chromatography-mass spectrometry(LC-MS)-based metabolomics analysis,higher contents of amino acids,monosaccharides,and quinic acids were found in stems than those in leaves.Inversely,higher contents of tea pigments,flavan-3-ols,gallic acid,purine alkaloids,and flavonol glycosides were present in tea leaves than in stems.LC-MS-based metabolomics also revealed that organic acids were the most critical non-volatile compounds responsible for the differences between tea stems and leaves.Furthermore,tea stems had better inhibiting effects of pro-inflammatory cytokines(interleukin(IL)-1βand IL-6)in lipopolysaccharide-challenged RAW264.7 macrophages than tea leaves,while no significant differences exist between leaves and stems for inhibiting the secretion of tumor necrosis factorα(TNF-α)and NO.In conclusion,our results support using Keemun black tea stems as a novel source of anti-inflammatory compounds.
文摘With the continuous advancement of artificial intelligence(AI)technology,personalized learning systems are increasingly applied in higher education.Particularly within STEM(Science,Technology,Engineering,and Mathematics)education,AI demonstrates significant advantages through adaptive learning pathways,instant feedback,and individualized resource allocation.However,current research predominantly focuses on the technical architecture and application effectiveness of such systems,with insufficient exploration of how AI-enabled personalized learning systems influence university students’learning motivation and academic achievement through educational psychological mechanisms.This paper adopts an educational psychology perspective to construct a causal mechanism model linking“learning motivation-learning behavior-academic achievement.”Findings indicate that AI-powered personalized learning systems enhance learning autonomy,boost self-efficacy,and optimize feedback mechanisms.These effects collectively stimulate university students’learning motivation in STEM disciplines,thereby promoting academic achievement.Building upon empirical research,this paper proposes implications for educational practice and policy formulation,emphasizing the necessity of advancing higher education reform through the dual influence of technology and psychological mechanisms.
基金supported by the National Key R&D Program of China,No.2019YFA0110300(to ZG)the National Natural Science Foundation of China,Nos.81773302(to YF),32070862(to ZG).
文摘Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.
文摘To investigate the differences in physical and chemical indicators of tobacco stems from different parts of the‘Honghuadajinyuan’variety in the Dali tobacco-growing area,a comparative analysis of these indicators was conducted.The results showed that in terms of physical indicators,the tobacco stem length and content in middle part were significantly higher than those in other parts;the filling value of cut stems in upper part was significantly better than that in the middle and lower parts.In terms of chemical compositions,the content of total sugar and reducing sugar in middle part were the highest;the content of nicotine,total chlorine,and chlorine in upper part were the highest;the difference between total sugar and reducing sugar,sugar-to-nicotine ratio,nitrogen-to-nicotine ratio,and potassium-to-chlorine ratio in middle part were the best;and the potassium content in lower part was significantly higher than that in other parts.Correlation analysis showed that equilibrium moisture content was significantly positively correlated with total nitrogen content.Among them,equilibrium moisture content in upper part was positively correlated with nicotine content,and equilibrium moisture content in middle part was positively correlated with potassium and chlorine content.In addition,the filling value of cut stems in lower part was positively correlated with reducing sugar and total nitrogen content,while the filling value of cut stems in all parts was negatively correlated with the difference between total sugar and reducing sugar,sugar-to-nicotine ratio,and nitrogen-to-nicotine ratio.
基金supported by Natural Science Foundation of Shandong Province(ZR2023JQ012)the National Natural Science Foundation of China(32101741)+1 种基金National Key Research and Development Program of China(2022YFD1201802)the Taishan Scholar Program of Shandong Provincial Government to F.X.,and National Natural Science Foundation of China(32201694 and U22A20460)to X.H.
文摘All plant organs are derived from stem cell-containing meristems.In maize,the shoot apical meristem(SAM)is responsible for generating all above-ground structures,including the male and female inflorescence meristems(IMs),which give rise to tassel and ear,respectively.Forward and reverse genetic studies on maize meristem mutants have driven forward our fundamental understanding of meristem maintenance and differentiation mechanisms.However,the high genetic redundancy of the maize genome has impeded progress in functional genomics.This review comprehensively summarizes recent advancements in understanding maize meristem development,with a focus on the integration of single-cell and spatial technologies.We discuss the mechanisms governing stem cell maintenance and differentiation in SAM and IM,emphasizing the roles of gene regulatory networks,hormonal pathways,and cellular omics insights into stress responses and adaptation.Future directions include cross-species comparisons,multi-omics integration,and the application of these technologies to precision breeding and stress adaptation research,with the ultimate goal of translating our understanding of meristem into the development of higher yield varieties.
基金Supported by the Special Fund of Hongyun Honghe Tobacco(Group)Co.,Ltd~~
文摘[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.
文摘Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ<sub>1-42</sub>-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ<sub>1-42</sub>, an injury model was established by subjecting OLN-93 cells to Aβ<sub>1-42</sub> exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ<sub>1-42</sub>. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ<sub>1-42</sub>-induced damage of OL.
基金Supported by Key Project of the National Twelfth-Five Year Research Program of China(2012BAC18B03)Natural Science Foundation of Hainan Province(414195,313106)~~
文摘In this study, 8 kinds of desiccation models and 3 kinds of collection models were studied for banana stems. The results showed that the crushing-com- pression-air drying processing model showed the best desiccation effect for banana stems. Under this desiccation model, the moisture content was reduced from 90.5% to 19.93% with weight reduced by 75.2%; after 3 to 6 months of storage, the mois- ture content was still remained within 17%-20%, and the volume was decreased to 30%-40% of the original volume of fresh banana stems. This desiccation model made banana stems basically meet the requirements by drying storage. The plant- cutting down-crushing-compression-transportation-desiccation-storage production model was initially developed for desiccation and collection of banana stems, which would lay a certain foundation for the utilization of banana stem resource by enterprises.
基金Supported by National Natural Science Foundation of China(31100401)~~
文摘[Objective] This study aimed to study the pharmacognostical properties of medicinal parts of stems and leaves of Viburnum Sargenti Koehne to provide refer- ence for its identification and application. [Method] Methods of characters and micro- scopic identification were used. [Result] Characters, transaction and microscopic characteristics of stems and leaves of V. sargenti Koehne were analyzed systemati- cally. [Conclusion] The experimental results can provide reference for the pharma- cognostical identification, further exploitation and utilization of stems and leaves of V. Sargenti Koehne.
基金supported by the National Natural Science Foundation of China (Nos. 30970167 and 31228002)the Zhejiang Qianjiang Talent Program (No. 2010R10084)+1 种基金the Zhejiang Provincial Natural Science Foundation of China (No. Z31100041)the Zhejiang Province Foundation for Returned Scholars (No. 20100129), China
文摘Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first mor- phological indication of trichome development is an increase in nuclear content resulting from an initial cycle of endoreduplication. Our previous study has shown that the C2H2 zinc finger protein GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome initiation in the inflorescence organ and for trichome branching in response to gibberellic acid signaling, although GIS gene does not play a direct role in regulating trichome cell division. Here, we describe a novel role of GIS, controlling trichome cell division indirectly by interacting genetically with a key endoreduplication regulator SIAMESE (SIM). Our molecular and genetic studies have shown that GIS might indireclty control cell division and trichome branching by acting downstream of SIM. A loss of function mutation of SIM signficantly reduced the expression of GIS. Futhermore, the overexpression of GIS rescued the trichome cluster cell phenotypes of sim mutant. The gain or loss of function of GIS had no significant effect on the expression of SIM. These results suggest that GIS may play an indirect role in regulating trichome cell division by genetically interacting with SIM.
基金Supported by UNAM-PAPIIT,No.IN219719 and No.IA205421CONACYT,No.A1-S-18285.
文摘Cancer stem cells(CSCs)are tumor cells that share functional characteristics with normal and embryonic stem cells.CSCs have increased tumor-initiating capacity and metastatic potential and lower sensitivity to chemo-and radiotherapy,with important roles in tumor progression and the response to therapy.Thus,a current goal of cancer research is to eliminate CSCs,necessitating an adequate phenotypic and functional characterization of CSCs.Strategies have been developed to identify,enrich,and track CSCs,many of which distinguish CSCs by evaluating the expression of surface markers,the initiation of specific signaling pathways,and the activation of master transcription factors that control stemness in normal cells.We review and discuss the use of reporter gene systems for identifying CSCs.Reporters that are under the control of aldehyde dehydrogenase 1A1,CD133,Notch,Nanog homeobox,Sex-determining region Y-box 2,and POU class 5 homeobox can be used to identify CSCs in many tumor types,track cells in real time,and screen for drugs.Thus,reporter gene systems,in combination with in vitro and in vivo functional assays,can assess changes in the CSCs pool.We present relevant examples of these systems in the evaluation of experimental CSCs-targeting therapeutics,demonstrating their value in CSCs research.
基金Supported by Science and Health Joint Medical Research Project of Chongqing,No.2022MSXM133Natural Science Foundation of Chongqing,No.CSTB2022NSCQ-MSX1522,No.CSTB2023NSCQ-MSX0246,No.CSTB2022NSCQ-MSX1271+1 种基金The First Batch of Key Disciplines on Public Health in Chongqing and ScienceHealth Joint Project of Dazu District Science and Technology Bureau,No.DZKJ,2022CCC1001.
文摘The complication of diabetes,which is known as diabetic foot ulcer(DFU),is a significant concern due to its association with high rates of disability and mortality.It not only severely affects patients’quality of life,but also imposes a substantial burden on the healthcare system.In spite of efforts made in clinical practice,treating DFU remains a challenging task.While mesenchymal stem cell(MSC)therapy has been extensively studied in treating DFU,the current efficacy of DFU healing using this method is still inadequate.However,in recent years,several MSCs-based drug delivery systems have emerged,which have shown to increase the efficacy of MSC therapy,especially in treating DFU.This review summarized the application of diverse MSCs-based drug delivery systems in treating DFU and suggested potential prospects for the future research.
基金Supported by Funding Project of Hebei Provincial Department of Education(ZD20131022,ZD2019057)First Batch Financial Support for Hebei Provincial Hundred Outstanding Innovative Talents in China.
文摘The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With the extensive application of S.baicalensis Georgi roots,the resource of S.baicalensis Georgi has been increasingly short.The above-ground part of stems and leaves of S.baicalensis Georgi has also been gradually recognized and developed.Studies have found that the chemical constituents from stems and leaves of S.baicalensis Georgi are also a group of flavonoids with a lot of pharmacological activity and have a great application value.Based on this,the present review will be reported on the chemical constituents and application of the roots,stems and leaves of S.baicalensis Georgi.
基金financially supported by the Natural Science Foundation of Shandong Province (ZR2017QB002)the key scientific research projects in Shandong Province (2018GGX104003)+2 种基金the Taishan Scholar Program of Shandong (ts201511033)the Foundation of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/ Shandong Province of China(No.KF201705)Shandong Province major innovation project (2018CXGC1001)
文摘Biomass activated carbon(BAC)was produced from ginger stems by carbonization and activation presented high specific surface areas and mesoporous structures.The carbonization temperature of the ginger stems were controlled within 500~900℃.The optimal carbonization condition is as follows:carbonization temperature of 700℃,carbonization time of 6 h.The determined optimum activation condition is:temperature of 800℃,activator of KOH and carbonized product/alkali ratio of 1:4(w/w).The carbonization yield,BAC yield and Brunauer-Emmett-Teller(BET)surface area were measured and the adsorption performance of BAC to nitrogen was investigated.The results showed that the nitrogen adsorption isotherm curve was as type I isotherm.It was finally determined that the BET surface area was 660 m2/g under the abovementioned optimal conditions of carbonization and activation.The FESEM analysis indicates that the obtained BAC is of micropore structure.
基金Supported by Key Technologies R &D Program of Guangdong Province (2009B0203030092006B20201007)~~
文摘[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS＋NAA 0.02 mg/L＋6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS＋NAA 0.02 mg/L＋6-BA 0.60 mg/L＋AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS＋NAA 0.40 mg/L＋IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.
基金Anchrom Laboratory,Mumbai,for providing the best available facility and kind support for this work
文摘Objective:To establish the standardization parameters for complete pharmacoguoslic evaluation of stems of Tlespesia lampas(T.lampas)(Cav.) Dalz & Gibs(Malvaceae),an important planl in the Indian system of medicine.Methods:Morphological,microscopical,physico-chemical evaluations,florescence analysis of T.lampas stems were investigated and preliminary phytochemical analysis,GO-MS analysis and HPTLC fingerprinting were carried out for qualitative phytochemical evaluation of various extracts of stems of T.lampas.Results:Chemomieroscopy revealed the presence of lignin.starch grains and calcium oxalate crystals.Physicochemical evaluation used to detennine numerical slandards showed a result with total ash(9.03± 0.05)%w/w,acid insoluble ash(1.50±0.01)%w/w,water soluble ash(2.51±0.02)%w/w,sulphated ash(7.50+0.01)%w/w,ethanol soluble extractive(0.24±0.02)%w/w,water soluble extractive(0.08 ±0.01)<7,w/w,moisture content(6.03±0.05)%w/w and total crude fibre content of stem powder(47.36±0.32)%w/w.Behavior characteristics of the stem powder showed presence of steroids, starch,alkaloid,flavonoids and proteins.Preliminary phytochemical analysis revealed presence of glycosides,phenolic compounds,tannins,steroids,saponins,flavonoids,carbohydrates and proteins.GC-MS analysis showed the presence of fatty acids such as dodecanoic acid, lelraclecanoic acid,n-hexadecanoic acid,9-lelradecenal and HPTLC fingerprinting revealed the presence of β-sitosterol and quercetin in stems of T.lampas.Conclusions:The pharmacognostic standardization of T.lampas is useful towards establishing standards for quality, purity and sample identification.
文摘Owing to the potential for intercell cochannel interference mitigation and significant spectral efficiency improvement, coordinating transmission techniques by multiple radio access points have recently attracted a lot of attention. In this paper, the system structure and mathematical signal model based on clustered structure are presented for multipoint coordinating downlink transmission, the clustered supercell configurations with static/dynamic approaches are discussed, and then optimal precod- ing design is provided for an accepted level of scheduling complexity and reduced signaling over- head. Some simulation results are given to evaluate the performance of different cell-clustering approaches, and to show that a clustered supercell size of 7 is a reasonable choice for clustered coordination with the given transmit power and the reduced feedback.
文摘a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of spectral analysis and chemical evidence.
基金Supported by Ningxia Agricultural Comprehensive Development Demonstration Project of Integration of Potato Green High-yielding and Mechanized Operation Techniques in 2015(NTKJ2016-09-03)
文摘In order to extract solanesol from potato stems and leaves more effectively and improve the extraction rate of solanesol, the same batch of potato stems and leaves harvested from Guyuan, Ningxia was selected as a research object, cell wall of potato stems and leaves was broken by enzymolysis with cellulase and high- speed shearing, and then reflux-extracted with 95% ethanol. Solanesol content was determined by HPLC, and extract yield was calculated. Extract yield and solanesol extraction rate was used as an index for comparison of difference between the 2 wall-breaking methods, so as to select the optimal wall-breaking method. The results showed that enzymolysis with cellulase exhibited extraction rate and extract yield of solanesol of 91.38% and 8.02%, respectively, which were better than those under high-speed shear emulsification technique. The enzymolysis wall-breaking method has the advantages of simple operation and strong feasibility.
基金Discipline Innovation Team of Shaanxi University of Traditional Chinese Medicine(No.2019-QN02)Project of Shaanxi Provincial Department of Education(Research and Development of Scutellaria Baicalensis Stem and Leaf and Honeysuckle Vine Anti Livestock and Poultry Infection Products)(No.20JC012)。
文摘Objective:The protective effect of Scutellaria baicalensis Stems and Polygonum Cuspidatum compatibility on lipopolysaccharide(LPS)-induced acute lung injury(ALI)in rats was studied by observing the expression of TRPV1 and inflammatory cytokines.Methods:48 male SD rats were randomly divided into 6 groups:control group,model group,dexamethasone group(5mg/kg)and Scutellaria baicalensis Stems-Polygonum Cuspidatum(3.5,7 and 14g/kg).The administration group was gavaged for 7 days,and the control group and model group were given the same amount of 0.9%sodium chloride.On the 8th day,except the control group,rats in other groups were injected with 8mg/kg LPS through caudal vein to induce Ali model.Take the rat lung tissue 6 hours after modeling,and calculate the wet/dry weight ratio(W/D)of the rat lung tissue;HE staining to observe the pathological changes of lung tissue;Determine the content of tumor necrosis factor-α(TNF-α)and interleukin-1β(1L-1β)in alveolar lavage fluid(BALF)and the activity of superoxide dismutase(SOD)in serum;Detect the mRNA and protein expression levels of TRPV1 receptor in rat lung tissue.Results:Compared with the model group,Scutellaria baicalensis Stems-Polygonum Cuspidatum can significantly reduce the damage of lung tissue structure and bleeding state,W/D value and TNF-α、IL-1βThe content of TRPV1 decreased,the level of SOD increased,and the mRNA and protein expression of TRPV1 receptor decreased.Conclusion:The combination of Scutellaria baicalensis Stems-Polygonum has a protective effect on acute lung injury in rats,and its mechanism may be related to down-regulating the expression of TRPV1 and inhibiting the levels of TNF-αand IL-1βin inflammatory cells.
