Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the mac...Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the machine is often transient and time-varying,which makes the sample annotation increasingly expensive.Meanwhile,the number of samples collected from different health states is often unbalanced.To deal with the above challenges,a complementary-label(CL)adversarial domain adaptation fault diagnosis network(CLADAN)is proposed under time-varying rotational speed and weakly-supervised conditions.In the weakly supervised learning condition,machine prior information is used for sample annotation via cost-friendly complementary label learning.A diagnosticmodel learning strategywith discretized category probabilities is designed to avoidmulti-peak distribution of prediction results.In adversarial training process,we developed virtual adversarial regularization(VAR)strategy,which further enhances the robustness of the model by adding adversarial perturbations in the target domain.Comparative experiments on two case studies validated the superior performance of the proposed method.展开更多
Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein re...Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein response inβcells remains unclear.Methods:To investigate this,we induced early-onset T1D in non-obese diabetic mice using streptozotocin.Subsequently,T1D mice were randomly assigned to receive either MSCs or phosphate-buffered saline.We observed the in vivo homing of MSCs and assessed their effectiveness by analyzing blood glucose levels,body weight,histopathology,pancreatic protein expression,and serum levels of cytokines,proinsulin,and C-peptide.Results:Infused MSCs were found in the lungs,liver,spleen,and pancreas of T1D mice.They exhibited various effects,including reducing blood glucose levels,regulating immunity,inhibiting inflammation,increasingβ-cell areas,and reducing the expression of key proteins in the unfolded protein response pathway.Fasting serum proinsulin and C-peptide levels were significantly higher in the MSCs treatment group than in the T1D model group.However,there was no significant difference in the biomarker ofβ-cell endoplasmic reticulum stress,the ratio of fasting serum proinsulin to C-peptide,between the two groups.Conclusion:Ourfindings reveal that MSCs infusion does not alleviate endoplasmic reticulum stress inβcells directly but modulates the unfolded protein response pathway to preserveβ-cell mass and function in T1D mice.展开更多
Inflammatory bowel disease(IBD)refers to a pair of prevalent conditions(Crohn’s disease and ulcerative colitis)distinguished by persistent inflammation of the large intestine.Procyanidin C1(PCC1)is a natu-rally occur...Inflammatory bowel disease(IBD)refers to a pair of prevalent conditions(Crohn’s disease and ulcerative colitis)distinguished by persistent inflammation of the large intestine.Procyanidin C1(PCC1)is a natu-rally occurring substance derived from grape seeds that has demonstrated notable anti-inflammatory properties.This study examines the potential utility of PCC1 as a treatment for IBD and subsequently examines the host-cell-and microbiome-related mechanisms underlying the detected therapeutic bene-fits.Working with a classic dextran sodium sulfate(DSS)-induced mouse IBD model,we show that PCC1 protects the mucosal barrier and thereby confers strong protective effects against IBD.PCC1 pretreatment resulted in anti-inflammatory effects and protection against multiple pathological phenotypes in the IBD model mice,including reduced weight loss,lower disease activity index(DAI)totals,and enhanced colon size,as well as obviously beneficial effects on the mucosal barrier(e.g.,barrier thickness and activity of mucus-degrading enzymes).We also analyzed the autophagy marker microtubule-associated protein1 light chain 3(LC3)and found that the level of LC3 was significantly elevated in the intestinal epithelial cell samples of the PCC1-pretreatment group as compared with the non-model mice samples.PCC1 altered the fecal microbiome composition,which included elevating the abundance of Akkermansia muci-niphila and Christensenella minuta.Fecal microbiome transplant(FMT)experiments showed that deliver-ing a microbiome from PCC1-treated animals into PCC1-naïve animals conferred protection.Metabolic profiling revealed that both the PCC1-pretreatment and PCC1 FMT groups had elevated levels of the microbiota-derived metabolite valeric acid,and supplementation with this short-chain fatty acid(SCFA)also conferred strong protection against IBD.Finally,inhibitor experiments confirmed that the beneficial effects of valeric acid on the mucus layer are mediated by FOXO1 signaling in the goblet cells of the intestinal epithelium.Beyond showing that PCC1 confers anti-inflammatory effects and protection against IBD by altering the microbiome,our study demonstrates proof of principle for multiple straight-forward interventions(PCC1,FMT,and valeric acid supplementation)for ameliorating mucosal barrier damage to treat IBD.展开更多
Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based ...Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based on virtual reality and gesture interaction.Methods The parameters of the models were obtained through actual investigation,whereby Blender and 3DS MAX were used to model and import these parameters into a physics engine.By establishing an interface for the physics engine,gesture interaction hardware,and virtual reality(VR)helmet,a highly realistic chemical experiment environment was created.Using code script logic,particle systems,as well as other systems,chemical phenomena were simulated.Furthermore,we created an online teaching platform using streaming media and databases to address the problems of distance teaching.Results The proposed system was evaluated against two mainstream products in the market.In the experiments,the proposed system outperformed the other products in terms of fidelity and practicality.Conclusions The proposed system which offers realistic simulations and practicability,can help improve the high school chemistry experimental education.展开更多
Atomically dispersed catalysts are widely adopted in CO_(2)reduction reaction(CO_(2)RR)due to maximal atomic utilization and high catalytic activity.Dual-atom catalysts(DACs),with more dispersed active sites and disti...Atomically dispersed catalysts are widely adopted in CO_(2)reduction reaction(CO_(2)RR)due to maximal atomic utilization and high catalytic activity.Dual-atom catalysts(DACs),with more dispersed active sites and distinct electronic structures compared with single-atom catalysts(SACs),may exhibit diverse catalytic performance.Herein,the DAC FeCo-NC and SAC Fe-NC/Co-NC are employed as probes to explore DACs advantage in CO_(2)RR.Results show that the moderate interaction between the dual-atom center and N coordination balances structural stability and catalytic activity.CO is the only product on Fe-NC/Co-NC,and the high limiting potentials from−1.22 to−1.67 V inhibit further reduction.FeCo-NC assisted with CO intermediate exhibits low limiting potentials of−0.64 V for both CH_(3)OH and CH 4,comparable to those on Cu-based catalysts.Under circumstance of applied potentials,CO_(2)RR on FeCo-NC has greater advantages in yielding CH_(3)OH and CH 4 than that on Fe-NC/Co-NC,and hydrogen evolution reaction is severely inhibited.The intrinsic essence is that dual-atom center can provide large spin-polarization and multi-electron transfer capability,rendering CO intermediates as effective electronic and geometric modifiers in CO_(2)RR.This work highlights FeCo-NC as a high-performance CO_(2)RR catalyst toward deep-reduction C1 products and elucidates CO intermediate assisted promotion mechanism via a dual-atom synergistic effect.展开更多
Cellulose nanocrystals(CNCs)can self-assemble in suspension to form chiral cholesteric structure of liquid crystal with unique birefringence phenomena,and the structural parameters strongly depend upon the aspect rati...Cellulose nanocrystals(CNCs)can self-assemble in suspension to form chiral cholesteric structure of liquid crystal with unique birefringence phenomena,and the structural parameters strongly depend upon the aspect ratio,surface structure,and physicochemical properties of CNC,along with suspension media.Many attempts have been carried out to keep this cholesteric structure in solid state via removing solvent,such as slower solvent-evaporation,rapid vacuum-filtration,and spin-casting under centrifugal force.The solid-state iridescence of the cholesteric CNC arrays has been used as structural color,and showed a great potential for the coding and securing of optical information.Moreover,to promote practical applications of such structural iridescence,the cholesteric CNC arrays have been embedded into many kinds of substrates via in-situ reaction of monomers or physical blending with polymers.However,this kind of structural iridescences may lead to misreading information.The uniaxial-orientation assembly of CNC has thus been proposed via regulating external force fields of CNC self-assembly,and successfully achieved nanoparticle assembly-induced solid-state monochrome emission based on enhanced inelastic collision theory of CNC dipoles and photons.This method can eliminate the chiral arrangement of CNC and the corresponding iridescence,and the structural monochromaticity can contribute to enhancing the accuracy of optical information.Overall,the CNC can be controllably assembled as the ordered arrays in solid state and presented structural color,and support optical anti-counterfeiting strategies different from the fluorescent technologies.展开更多
With the efficient development of social economy,as well as the acceleration of the pace of life,the incidence of hemorrhoids remains high all year round,occupying a relatively high incidence of anorectal diseases.The...With the efficient development of social economy,as well as the acceleration of the pace of life,the incidence of hemorrhoids remains high all year round,occupying a relatively high incidence of anorectal diseases.The author will sort out the four most representative theories of pathogenesis,and summarize and analyze them.Understanding the pathogenesis of hemorrhoids can give a deeper understanding of the nature of the disease,and it will help improve the accuracy of clinical diagnosis and treatment,which in turn is beneficial to the improvement of the cure rate.展开更多
In variational methods,coupled parameter optimization(CPO) often needs a long minimization time window(MTW) to fully incorporate observational information,but the optimal MTW somehow depends on the model nonlinearity....In variational methods,coupled parameter optimization(CPO) often needs a long minimization time window(MTW) to fully incorporate observational information,but the optimal MTW somehow depends on the model nonlinearity.The analytical four-dimensional ensemble-variational(A-4DEnVar) considers model nonlinearity well and avoids adjoint model.It can theoretically be applied to CPO.To verify the feasibility and the ability of the A-4DEnVar in CPO,“twin” experiments based on A-4DEnVar CPO are conducted for the first time with the comparison of four-dimensional variational(4D-Var).Two algorithms use the same background error covariance matrix and optimization algorithm to control variates.The experiments are based on a simple coupled oceanatmosphere model,in which the atmospheric part is the highly nonlinear Lorenz-63 model,and the oceanic part is a slab ocean model.The results show that both A-4DEnVar and 4D-Var can effectively reduce the error of state variables through CPO.Besides,two methods produce almost the same results in most cases when the MTW is less than 560 time steps.The results are similar when the MTW is larger than 560 time steps and less than 880 time steps.The largest MTW of 4 D-Var and A-4DEnVar are 1 200 time steps.Moreover,A-4DEnVar is not sensitive to ensemble size when the MTW is less than 720 time steps.A-4DEnVar obtains satisfactory results in the case of highly nonlinear model and long MTW,suggesting that it has the potential to be widely applied to realistic CPO.展开更多
光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感...光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感基础上考虑垂直于电磁波传播方向的二维偏振矢量特性(强度+方向)就能深化为矢量遥感体系,从而有望精确刻画反射光中蕴含的多种信息,提升植被参数反演精度.刻画偏振反射空间分布的双向偏振分布函数BPDF目前存在精度低、泛化性差等问题,因此进一步探索矢量遥感基础理论,构建通用性强的植被矢量遥感基础模型具有迫切的现实需求.本文旨在利用光子与植被元素的相互作用构建通用性较强的植被BPDF物理模型.首先基于光子–植被元素相互作用的光谱不变原理,提出基于方向逃逸概率的植被BPDF物理模型基础形式,并基于植被单次反射的辐射传输理论推导模型解析表达;随后通过考虑叶片散射随干物质含量的变化,提出光谱不变原理优化表达并推导模型通用表达式;最后分别利用三维矢量辐射传输模型和多尺度实测数据实现模型的正演直接验证和间接验证.结果表明,本文构建的BPDF物理模型的解析表达和通用表达在不同植被场景下,对偏振反射率的正演均方根误差可达0.001以内,与矢量辐射传输模型正演结果在半球空间内具有很强一致性,在多尺度实测数据也简洁验证了模型关系的稳定性,模型R2普遍高于0.9.相比于现存植被偏振反射模型,本文构建的模型兼具物理机理、简洁形式、可接受的参数化方案、较高精度和较强泛化能力,对浓密植被具备通用性,为在BRDF一维标量遥感的基础上进一步考虑BPDF二维偏振特性从而形成矢量遥感体系这一转变过程提供了理论基础和探索性方案.展开更多
Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.B...Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.Bone morphogenetic protein 9(BMP9)can commit mesenchymal stem cells to osteogenic lineage,and a knowledge of the underlying mechanisms may help advance the field of bone tissue engineering.Leucine-rich repeats con-taining G protein-coupled receptor 4(LGR4),a member of G protein-coupled receptors,is essential for modulating bone development.This study is aimed at investigating the impact of LGR4 on BMP9-induced osteogenesis in mesenchymal stem cells as well as the underlying mechanisms.Bone marrow stromal cells from BMp9-knockout mice exhibited diminished LGR4 expression,and exogenous LGR4 clearly restored the impaired osteogenic potency of the bone marrow stromal cells.Furthermore,LGR4 expression was increased by BMP9 in C3H10T1/2 cells.LGR4 augmented the benefits of BMP9-induced osteogenic markers and bone formation,whereas LGR4 inhibition restricted these effects.Meanwhile,the BMP9-induced li-pogenic markers were increased by LGR4 inhibition.The protein levels of Raptor and p-Stat3 were elevated by BMP9.Raptor knockdown or p-Stat3 suppression attenuated the osteoblastic markers and LGR4 expression brought on by BMP9.LGR4 significantly reversed the blocking ef-fect of Raptor knockdown or p-Stat3 suppression on the BMP9-induced osteoblastic markers.Raptor interacts with p-Stat3,and p-Stat3 activates the LGR4 promoter activity.In conclusion,LGR4 boosts BMP9 osteoblastic potency in mesenchymal stem cells,and BMP9 may up-regulate LGR4 via the mTORC1/Stat3 signal activation.展开更多
Recent years have witnessed the transformative impact from the integration of artificial intelligence with organic and polymer synthesis. This synergy offers innovative and intelligent solutions to a range of classic ...Recent years have witnessed the transformative impact from the integration of artificial intelligence with organic and polymer synthesis. This synergy offers innovative and intelligent solutions to a range of classic problems in synthetic chemistry. These exciting advancements include the prediction of molecular property, multi-step retrosynthetic pathway planning, elucidation of the structure-performance relationship of single-step transformation, establishment of the quantitative linkage between polymer structures and their functions, design and optimization of polymerization process, prediction of the structure and sequence of biological macromolecules, as well as automated and intelligent synthesis platforms. Chemists can now explore synthetic chemistry with unprecedented precision and efficiency, creating novel reactions, catalysts, and polymer materials under the datadriven paradigm. Despite these thrilling developments, the field of artificial intelligence(AI) synthetic chemistry is still in its infancy, facing challenges and limitations in terms of data openness, model interpretability, as well as software and hardware support. This review aims to provide an overview of the current progress, key challenges, and future development suggestions in the interdisciplinary field between AI and synthetic chemistry. It is hoped that this overview will offer readers a comprehensive understanding of this emerging field, inspiring and promoting further scientific research and development.展开更多
Controlled and switchable adhesion is commonly observed in biological systems.In recent years,many scholars have focused on making switchable bio-inspired adhesives.However,making a bio-inspired adhesive with high adh...Controlled and switchable adhesion is commonly observed in biological systems.In recent years,many scholars have focused on making switchable bio-inspired adhesives.However,making a bio-inspired adhesive with high adhesion performance and excellent dynamic switching properties is still a challenge.A Shape Memory Polymer Bio-inspired Adhesive(SMPBA)was successfully developed,well realizing high adhesion(about 337 kPa),relatively low preload(about90 kPa),high adhesion-to-preload ratio(about 3.74),high switching ratio(about 6.74),and easy detachment,which are attributed to the controlled modulus and contact area by regulating temperature and the Shape Memory Effect(SME).Furthermore,SMPBA exhibits adhesion strength of80–337 kPa on various surfaces(silicon,iron,and aluminum)with different roughness(Ra=0.021–10.280)because of the conformal contact,reflecting outstanding surface adaptability.The finite element analysis verifies the bending ability under different temperatures,while the adhesion model analyzes the influence of preload on contact area and adhesion.Furthermore,an Unmanned Aerial Vehicle(UAV)landing device with SMPBA was designed and manufactured to achieve UAV landing on and detaching from various surfaces.This study provides a novel switchable bio-inspired adhesive and UAV landing method.展开更多
Dietary fat content can reduce the methane production of dairy cows;however,the relevance fatty acid(FA)composition has towards this inhibitory effect is debatable.Furthermore,in-depth studies elucidating the effects ...Dietary fat content can reduce the methane production of dairy cows;however,the relevance fatty acid(FA)composition has towards this inhibitory effect is debatable.Furthermore,in-depth studies elucidating the effects of unsaturated fatty acids(UFA)on rumen function and the mechanism of reducing methane(CH_(4))production are lacking.This study exposed 10 Holstein cows with the same parity,similar milk yield to two total mixed rations:low unsaturated FA(LUFA)and high unsaturated FA(HUFA)with similar fat content.The LUFA group mainly added fat powder(C16:0>90%),and the HUFA group mainly replaced fat powder with extruded flaxseed.The experiment lasted 26 d,the last 5 d of which,gas exchange in respiratory chambers was conducted to measure gas emissions.We found that an increase in the UFA in diet did not affect milk production(P>0.05)and could align the profile of milk FAs more closely with modern human nutritional requirements.Furthermore,we found that increasing the UFA content in the diet lead to a decrease in the abundance of Methanobrevibacter in the rumen(|linear discriminant analysis[LDA]score|>2 and P 2 and P<0.05),which ultimately decreased CH4 production(P<0.05).Our results illustrated the mechanism involving decreased CH4 production when fed a UFA diet in dairy cows.We believe that our study provides new evidence to explore CH4 emission reduction measures for dairy cows.展开更多
Independent light propagation through one or multiple modes is commonly considered as a basic demand for mode manipulation in few-mode fiber(FMF)-or multimode fiber(MMF)-based optical systems such as transmission link...Independent light propagation through one or multiple modes is commonly considered as a basic demand for mode manipulation in few-mode fiber(FMF)-or multimode fiber(MMF)-based optical systems such as transmission links,optical fiber lasers,or distributed optical fiber sensors.However,the insertion of doped-fiber amplifiers always kills the entire effort by inducing significant modal crosstalk.In this paper,we propose the design of doped-fiber amplifiers in FMF-based systems adopting identical multiple-ring-core(MRC)index profiles for both passive and doped fibers to achieve low modal crosstalk.We develop the direct-glass-transition(DGT)modified chemical vapor deposition(MCVD)processing for precise fabrication of few-mode erbium-doped fibers(FM-EDFs)with MRC profiles of both refractive index and erbium-ion doping distribution.Then,a few-mode erbium-doped-fiber amplifier(FM-EDFA)with a maximum gain of 26.08 dB and differential modal gain(DMG)of 2.3 dB is realized based on fabricated FM-EDF matched with a transmission FMF supporting four linearly polarized(LP)modes.With the insertion of the FM-EDFA,60+60 km simultaneous LP_(01)∕LP_(11)∕LP_(21)∕LP_(02)transmission without inter-modal multiple-input multiple-output digital signal processing(MIMO-DSP)is successfully demonstrated.The proposed design of low-modal-crosstalk doped-fiber amplifiers provides,to our knowledge,new insights into mode manipulation methods in various applications.展开更多
A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently.A low in put voltage is essential to en sure the heaters saf...A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently.A low in put voltage is essential to en sure the heaters safe applications.However,the low voltage gen erally leads to low saturated temperature and heati ng rate and hence a low thermal efficie ncy.How to reduce the in put voltage while maintai ning a high electro-thermal efficiency is still a challenge.Herein,a highly electrical and thermal conductive film was 8nstructed using a graphene-based composite which has an internal three-dimensional(3D)conductive network.In the 3D framework,cellulose nanocrystalline(CNC)phase with chiral liquid crystal manner presents in the form of alig ned helix betwee n the graphe ne oxide(GO)layers.Carbon nano dots(CDs)are assembled泊side the composite as con ductive nano fillers.Subseque nt an neali ng and compressi on results in the formati on of the assembled GO-CNC-CDs film.The carb on ized CNC nano rods(CNR)with the helical alignment act as irrplane and through-pla ne conn ecti ons of n eighbori ng reduced GO(rGO)nano sheets,forming a con ductive network in the composite film.The CDs with ultrafast electr ons tran sfer rates provide additi onal electro ns and phonons tran sport paths for the composite.As a result,the obtai ned graphe ne?based composite film(rGO-CNR-CDs)exhibited a high thermal conductivity of 1,978.6 W m^-1·K^-1 and electrical conductivity of 2,053.4 S·cm^-1,respectively.The composite film showed an outstanding electro-thermal heating efficiency with the saturated temperature of 315℃and maximum heating rate of 44.9℃·s^-1 at a very low in put voltage of 10 V.The freestandi ng graphe ne composite film with the delicate nano structure desig n has a great pote ntial to be integrated into electro-thermal devices.展开更多
Dear Editor,Most human genetic diseases arise from mutations such as insertion,deletion,or point mutations(Landrum et al.,2016).CRISPRCas system has been repurposed to correct pathogenic mutations in a variety of gene...Dear Editor,Most human genetic diseases arise from mutations such as insertion,deletion,or point mutations(Landrum et al.,2016).CRISPRCas system has been repurposed to correct pathogenic mutations in a variety of genetic diseases(Choi et al.,2022).There are many concerns about using CRISPR-mediated double-stranded DNA breaks(DSBs)for therapeutic purposes,primarily due to off-targeted mutations(Kosicki et al.,2018).Nevertheless,base editing cannot correct deletions,insertions,or some point mutations such as transversion mutations.Prime editing has its advantages of precisely correct point mutations,small insertions,or deletions in animal cells(Anzalone et al.,2019)and plants(Lin et al.,2020).However,prime editing efficiency varies among genomic sites or cell types(Chen et al.,2021;Nelson et al.,2022).展开更多
基金Shanxi Scholarship Council of China(2022-141)Fundamental Research Program of Shanxi Province(202203021211096).
文摘Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the machine is often transient and time-varying,which makes the sample annotation increasingly expensive.Meanwhile,the number of samples collected from different health states is often unbalanced.To deal with the above challenges,a complementary-label(CL)adversarial domain adaptation fault diagnosis network(CLADAN)is proposed under time-varying rotational speed and weakly-supervised conditions.In the weakly supervised learning condition,machine prior information is used for sample annotation via cost-friendly complementary label learning.A diagnosticmodel learning strategywith discretized category probabilities is designed to avoidmulti-peak distribution of prediction results.In adversarial training process,we developed virtual adversarial regularization(VAR)strategy,which further enhances the robustness of the model by adding adversarial perturbations in the target domain.Comparative experiments on two case studies validated the superior performance of the proposed method.
文摘Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein response inβcells remains unclear.Methods:To investigate this,we induced early-onset T1D in non-obese diabetic mice using streptozotocin.Subsequently,T1D mice were randomly assigned to receive either MSCs or phosphate-buffered saline.We observed the in vivo homing of MSCs and assessed their effectiveness by analyzing blood glucose levels,body weight,histopathology,pancreatic protein expression,and serum levels of cytokines,proinsulin,and C-peptide.Results:Infused MSCs were found in the lungs,liver,spleen,and pancreas of T1D mice.They exhibited various effects,including reducing blood glucose levels,regulating immunity,inhibiting inflammation,increasingβ-cell areas,and reducing the expression of key proteins in the unfolded protein response pathway.Fasting serum proinsulin and C-peptide levels were significantly higher in the MSCs treatment group than in the T1D model group.However,there was no significant difference in the biomarker ofβ-cell endoplasmic reticulum stress,the ratio of fasting serum proinsulin to C-peptide,between the two groups.Conclusion:Ourfindings reveal that MSCs infusion does not alleviate endoplasmic reticulum stress inβcells directly but modulates the unfolded protein response pathway to preserveβ-cell mass and function in T1D mice.
基金supported by the 111 projects of the Education Ministry of China(B18053)the National Natural Science Foundation(32130081)+1 种基金the National Key Research and Development Program of China(2022YFF0710402)the Pinduoduo-China Agricultural University Research Fund(PC2023B01014).
文摘Inflammatory bowel disease(IBD)refers to a pair of prevalent conditions(Crohn’s disease and ulcerative colitis)distinguished by persistent inflammation of the large intestine.Procyanidin C1(PCC1)is a natu-rally occurring substance derived from grape seeds that has demonstrated notable anti-inflammatory properties.This study examines the potential utility of PCC1 as a treatment for IBD and subsequently examines the host-cell-and microbiome-related mechanisms underlying the detected therapeutic bene-fits.Working with a classic dextran sodium sulfate(DSS)-induced mouse IBD model,we show that PCC1 protects the mucosal barrier and thereby confers strong protective effects against IBD.PCC1 pretreatment resulted in anti-inflammatory effects and protection against multiple pathological phenotypes in the IBD model mice,including reduced weight loss,lower disease activity index(DAI)totals,and enhanced colon size,as well as obviously beneficial effects on the mucosal barrier(e.g.,barrier thickness and activity of mucus-degrading enzymes).We also analyzed the autophagy marker microtubule-associated protein1 light chain 3(LC3)and found that the level of LC3 was significantly elevated in the intestinal epithelial cell samples of the PCC1-pretreatment group as compared with the non-model mice samples.PCC1 altered the fecal microbiome composition,which included elevating the abundance of Akkermansia muci-niphila and Christensenella minuta.Fecal microbiome transplant(FMT)experiments showed that deliver-ing a microbiome from PCC1-treated animals into PCC1-naïve animals conferred protection.Metabolic profiling revealed that both the PCC1-pretreatment and PCC1 FMT groups had elevated levels of the microbiota-derived metabolite valeric acid,and supplementation with this short-chain fatty acid(SCFA)also conferred strong protection against IBD.Finally,inhibitor experiments confirmed that the beneficial effects of valeric acid on the mucus layer are mediated by FOXO1 signaling in the goblet cells of the intestinal epithelium.Beyond showing that PCC1 confers anti-inflammatory effects and protection against IBD by altering the microbiome,our study demonstrates proof of principle for multiple straight-forward interventions(PCC1,FMT,and valeric acid supplementation)for ameliorating mucosal barrier damage to treat IBD.
基金National Innovation and Entrepreneurship Program for College Students(202218213001)Science and Technology Innovation Strategy of Guangdong Province(Science and Technology Innovation Cultivation of University Students 2020329182130C000002).
文摘Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based on virtual reality and gesture interaction.Methods The parameters of the models were obtained through actual investigation,whereby Blender and 3DS MAX were used to model and import these parameters into a physics engine.By establishing an interface for the physics engine,gesture interaction hardware,and virtual reality(VR)helmet,a highly realistic chemical experiment environment was created.Using code script logic,particle systems,as well as other systems,chemical phenomena were simulated.Furthermore,we created an online teaching platform using streaming media and databases to address the problems of distance teaching.Results The proposed system was evaluated against two mainstream products in the market.In the experiments,the proposed system outperformed the other products in terms of fidelity and practicality.Conclusions The proposed system which offers realistic simulations and practicability,can help improve the high school chemistry experimental education.
基金This work was supported by Shandong Natural Science Foundation,China(ZR2019MEM005,ZR2020ME053,and ZR2020QB027)the Major Scientific and Technological Projects of CNPC(ZD2019-184-001)+1 种基金the Fundamental Research Funds for the Central Universities(18CX02042A and 20CX05010A)the National Science Fund for Distinguished Young Scholars(22101300).
文摘Atomically dispersed catalysts are widely adopted in CO_(2)reduction reaction(CO_(2)RR)due to maximal atomic utilization and high catalytic activity.Dual-atom catalysts(DACs),with more dispersed active sites and distinct electronic structures compared with single-atom catalysts(SACs),may exhibit diverse catalytic performance.Herein,the DAC FeCo-NC and SAC Fe-NC/Co-NC are employed as probes to explore DACs advantage in CO_(2)RR.Results show that the moderate interaction between the dual-atom center and N coordination balances structural stability and catalytic activity.CO is the only product on Fe-NC/Co-NC,and the high limiting potentials from−1.22 to−1.67 V inhibit further reduction.FeCo-NC assisted with CO intermediate exhibits low limiting potentials of−0.64 V for both CH_(3)OH and CH 4,comparable to those on Cu-based catalysts.Under circumstance of applied potentials,CO_(2)RR on FeCo-NC has greater advantages in yielding CH_(3)OH and CH 4 than that on Fe-NC/Co-NC,and hydrogen evolution reaction is severely inhibited.The intrinsic essence is that dual-atom center can provide large spin-polarization and multi-electron transfer capability,rendering CO intermediates as effective electronic and geometric modifiers in CO_(2)RR.This work highlights FeCo-NC as a high-performance CO_(2)RR catalyst toward deep-reduction C1 products and elucidates CO intermediate assisted promotion mechanism via a dual-atom synergistic effect.
基金the National Natural Science Foundation of China(51603171)Fundamental Research Funds for the Central Universities(XDJK2016C032)the Talent Project of Southwest University(SWU115034)
文摘Cellulose nanocrystals(CNCs)can self-assemble in suspension to form chiral cholesteric structure of liquid crystal with unique birefringence phenomena,and the structural parameters strongly depend upon the aspect ratio,surface structure,and physicochemical properties of CNC,along with suspension media.Many attempts have been carried out to keep this cholesteric structure in solid state via removing solvent,such as slower solvent-evaporation,rapid vacuum-filtration,and spin-casting under centrifugal force.The solid-state iridescence of the cholesteric CNC arrays has been used as structural color,and showed a great potential for the coding and securing of optical information.Moreover,to promote practical applications of such structural iridescence,the cholesteric CNC arrays have been embedded into many kinds of substrates via in-situ reaction of monomers or physical blending with polymers.However,this kind of structural iridescences may lead to misreading information.The uniaxial-orientation assembly of CNC has thus been proposed via regulating external force fields of CNC self-assembly,and successfully achieved nanoparticle assembly-induced solid-state monochrome emission based on enhanced inelastic collision theory of CNC dipoles and photons.This method can eliminate the chiral arrangement of CNC and the corresponding iridescence,and the structural monochromaticity can contribute to enhancing the accuracy of optical information.Overall,the CNC can be controllably assembled as the ordered arrays in solid state and presented structural color,and support optical anti-counterfeiting strategies different from the fluorescent technologies.
文摘With the efficient development of social economy,as well as the acceleration of the pace of life,the incidence of hemorrhoids remains high all year round,occupying a relatively high incidence of anorectal diseases.The author will sort out the four most representative theories of pathogenesis,and summarize and analyze them.Understanding the pathogenesis of hemorrhoids can give a deeper understanding of the nature of the disease,and it will help improve the accuracy of clinical diagnosis and treatment,which in turn is beneficial to the improvement of the cure rate.
基金The National Key Research and Development Program under contract No.2021YFC3101501the National Natural Science Foundation of China under contract No.41876014。
文摘In variational methods,coupled parameter optimization(CPO) often needs a long minimization time window(MTW) to fully incorporate observational information,but the optimal MTW somehow depends on the model nonlinearity.The analytical four-dimensional ensemble-variational(A-4DEnVar) considers model nonlinearity well and avoids adjoint model.It can theoretically be applied to CPO.To verify the feasibility and the ability of the A-4DEnVar in CPO,“twin” experiments based on A-4DEnVar CPO are conducted for the first time with the comparison of four-dimensional variational(4D-Var).Two algorithms use the same background error covariance matrix and optimization algorithm to control variates.The experiments are based on a simple coupled oceanatmosphere model,in which the atmospheric part is the highly nonlinear Lorenz-63 model,and the oceanic part is a slab ocean model.The results show that both A-4DEnVar and 4D-Var can effectively reduce the error of state variables through CPO.Besides,two methods produce almost the same results in most cases when the MTW is less than 560 time steps.The results are similar when the MTW is larger than 560 time steps and less than 880 time steps.The largest MTW of 4 D-Var and A-4DEnVar are 1 200 time steps.Moreover,A-4DEnVar is not sensitive to ensemble size when the MTW is less than 720 time steps.A-4DEnVar obtains satisfactory results in the case of highly nonlinear model and long MTW,suggesting that it has the potential to be widely applied to realistic CPO.
文摘光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感基础上考虑垂直于电磁波传播方向的二维偏振矢量特性(强度+方向)就能深化为矢量遥感体系,从而有望精确刻画反射光中蕴含的多种信息,提升植被参数反演精度.刻画偏振反射空间分布的双向偏振分布函数BPDF目前存在精度低、泛化性差等问题,因此进一步探索矢量遥感基础理论,构建通用性强的植被矢量遥感基础模型具有迫切的现实需求.本文旨在利用光子与植被元素的相互作用构建通用性较强的植被BPDF物理模型.首先基于光子–植被元素相互作用的光谱不变原理,提出基于方向逃逸概率的植被BPDF物理模型基础形式,并基于植被单次反射的辐射传输理论推导模型解析表达;随后通过考虑叶片散射随干物质含量的变化,提出光谱不变原理优化表达并推导模型通用表达式;最后分别利用三维矢量辐射传输模型和多尺度实测数据实现模型的正演直接验证和间接验证.结果表明,本文构建的BPDF物理模型的解析表达和通用表达在不同植被场景下,对偏振反射率的正演均方根误差可达0.001以内,与矢量辐射传输模型正演结果在半球空间内具有很强一致性,在多尺度实测数据也简洁验证了模型关系的稳定性,模型R2普遍高于0.9.相比于现存植被偏振反射模型,本文构建的模型兼具物理机理、简洁形式、可接受的参数化方案、较高精度和较强泛化能力,对浓密植被具备通用性,为在BRDF一维标量遥感的基础上进一步考虑BPDF二维偏振特性从而形成矢量遥感体系这一转变过程提供了理论基础和探索性方案.
基金All animal experiments were approved by The Ethics Committee of Chongqing Medical University(No.2022030).
文摘Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.Bone morphogenetic protein 9(BMP9)can commit mesenchymal stem cells to osteogenic lineage,and a knowledge of the underlying mechanisms may help advance the field of bone tissue engineering.Leucine-rich repeats con-taining G protein-coupled receptor 4(LGR4),a member of G protein-coupled receptors,is essential for modulating bone development.This study is aimed at investigating the impact of LGR4 on BMP9-induced osteogenesis in mesenchymal stem cells as well as the underlying mechanisms.Bone marrow stromal cells from BMp9-knockout mice exhibited diminished LGR4 expression,and exogenous LGR4 clearly restored the impaired osteogenic potency of the bone marrow stromal cells.Furthermore,LGR4 expression was increased by BMP9 in C3H10T1/2 cells.LGR4 augmented the benefits of BMP9-induced osteogenic markers and bone formation,whereas LGR4 inhibition restricted these effects.Meanwhile,the BMP9-induced li-pogenic markers were increased by LGR4 inhibition.The protein levels of Raptor and p-Stat3 were elevated by BMP9.Raptor knockdown or p-Stat3 suppression attenuated the osteoblastic markers and LGR4 expression brought on by BMP9.LGR4 significantly reversed the blocking ef-fect of Raptor knockdown or p-Stat3 suppression on the BMP9-induced osteoblastic markers.Raptor interacts with p-Stat3,and p-Stat3 activates the LGR4 promoter activity.In conclusion,LGR4 boosts BMP9 osteoblastic potency in mesenchymal stem cells,and BMP9 may up-regulate LGR4 via the mTORC1/Stat3 signal activation.
基金supported by the National Natural Science Foundation of China (22393890, You SL22393891 and 22031006,Luo S+16 种基金2203300, Pei J22371052, Chen M21991132, 21925102,92056118, and 22331003, Zhang WB22331002 and 22125101, Lu H22071004, Mo F22393892 and 22071249, Liao K22122109 and22271253, Hong X)the National Key R&D Program of China(2023YFF1205103, Pei J2020YFA0908100 and 2023YFF1204401, Zhang WB2022YFA1504301, Hong X)Zhejiang Provincial Natural Science Foundation of China (LDQ23B020002, Hong X)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study (SNZJU-SIAS-006, Hong X)the CAS Youth Interdisciplinary Team (JCTD-2021-11, Hong X)Shenzhen Medical Research Fund (B2302037, Zhang WB)Beijing National Laboratory for Molecular Sciences (BNLMSCXXM-202006, Zhang WB)the State Key Laboratory of Molecular Engineering of Polymers (Chen M)Haihe Laboratory of Sustainable Chemical Transformations and National Science&Technology Fundamental Resource Investigation Program of China (2023YFA1500008, Luo S)。
文摘Recent years have witnessed the transformative impact from the integration of artificial intelligence with organic and polymer synthesis. This synergy offers innovative and intelligent solutions to a range of classic problems in synthetic chemistry. These exciting advancements include the prediction of molecular property, multi-step retrosynthetic pathway planning, elucidation of the structure-performance relationship of single-step transformation, establishment of the quantitative linkage between polymer structures and their functions, design and optimization of polymerization process, prediction of the structure and sequence of biological macromolecules, as well as automated and intelligent synthesis platforms. Chemists can now explore synthetic chemistry with unprecedented precision and efficiency, creating novel reactions, catalysts, and polymer materials under the datadriven paradigm. Despite these thrilling developments, the field of artificial intelligence(AI) synthetic chemistry is still in its infancy, facing challenges and limitations in terms of data openness, model interpretability, as well as software and hardware support. This review aims to provide an overview of the current progress, key challenges, and future development suggestions in the interdisciplinary field between AI and synthetic chemistry. It is hoped that this overview will offer readers a comprehensive understanding of this emerging field, inspiring and promoting further scientific research and development.
基金financial support from the National Natural Science Foundation of China(No.51605220)the Jiangsu Province Natural Science Foundation,China(No.BK20160793)+1 种基金the Postgraduate Research and Practice Innovation Program of Nanjing University of Aeronautics and Astronautics,China(No.xcxjh20210514)the Fundamental Research Funds for the Central Universities,China(No.XCA2205406)。
文摘Controlled and switchable adhesion is commonly observed in biological systems.In recent years,many scholars have focused on making switchable bio-inspired adhesives.However,making a bio-inspired adhesive with high adhesion performance and excellent dynamic switching properties is still a challenge.A Shape Memory Polymer Bio-inspired Adhesive(SMPBA)was successfully developed,well realizing high adhesion(about 337 kPa),relatively low preload(about90 kPa),high adhesion-to-preload ratio(about 3.74),high switching ratio(about 6.74),and easy detachment,which are attributed to the controlled modulus and contact area by regulating temperature and the Shape Memory Effect(SME).Furthermore,SMPBA exhibits adhesion strength of80–337 kPa on various surfaces(silicon,iron,and aluminum)with different roughness(Ra=0.021–10.280)because of the conformal contact,reflecting outstanding surface adaptability.The finite element analysis verifies the bending ability under different temperatures,while the adhesion model analyzes the influence of preload on contact area and adhesion.Furthermore,an Unmanned Aerial Vehicle(UAV)landing device with SMPBA was designed and manufactured to achieve UAV landing on and detaching from various surfaces.This study provides a novel switchable bio-inspired adhesive and UAV landing method.
基金supported by the National Key R&D Program of China (No.2022YFD1301001).
文摘Dietary fat content can reduce the methane production of dairy cows;however,the relevance fatty acid(FA)composition has towards this inhibitory effect is debatable.Furthermore,in-depth studies elucidating the effects of unsaturated fatty acids(UFA)on rumen function and the mechanism of reducing methane(CH_(4))production are lacking.This study exposed 10 Holstein cows with the same parity,similar milk yield to two total mixed rations:low unsaturated FA(LUFA)and high unsaturated FA(HUFA)with similar fat content.The LUFA group mainly added fat powder(C16:0>90%),and the HUFA group mainly replaced fat powder with extruded flaxseed.The experiment lasted 26 d,the last 5 d of which,gas exchange in respiratory chambers was conducted to measure gas emissions.We found that an increase in the UFA in diet did not affect milk production(P>0.05)and could align the profile of milk FAs more closely with modern human nutritional requirements.Furthermore,we found that increasing the UFA content in the diet lead to a decrease in the abundance of Methanobrevibacter in the rumen(|linear discriminant analysis[LDA]score|>2 and P 2 and P<0.05),which ultimately decreased CH4 production(P<0.05).Our results illustrated the mechanism involving decreased CH4 production when fed a UFA diet in dairy cows.We believe that our study provides new evidence to explore CH4 emission reduction measures for dairy cows.
基金Pengcheng Zili Project(PCL2023A04)National Natural Science Foundation of China(62101009,U20A20160)。
文摘Independent light propagation through one or multiple modes is commonly considered as a basic demand for mode manipulation in few-mode fiber(FMF)-or multimode fiber(MMF)-based optical systems such as transmission links,optical fiber lasers,or distributed optical fiber sensors.However,the insertion of doped-fiber amplifiers always kills the entire effort by inducing significant modal crosstalk.In this paper,we propose the design of doped-fiber amplifiers in FMF-based systems adopting identical multiple-ring-core(MRC)index profiles for both passive and doped fibers to achieve low modal crosstalk.We develop the direct-glass-transition(DGT)modified chemical vapor deposition(MCVD)processing for precise fabrication of few-mode erbium-doped fibers(FM-EDFs)with MRC profiles of both refractive index and erbium-ion doping distribution.Then,a few-mode erbium-doped-fiber amplifier(FM-EDFA)with a maximum gain of 26.08 dB and differential modal gain(DMG)of 2.3 dB is realized based on fabricated FM-EDF matched with a transmission FMF supporting four linearly polarized(LP)modes.With the insertion of the FM-EDFA,60+60 km simultaneous LP_(01)∕LP_(11)∕LP_(21)∕LP_(02)transmission without inter-modal multiple-input multiple-output digital signal processing(MIMO-DSP)is successfully demonstrated.The proposed design of low-modal-crosstalk doped-fiber amplifiers provides,to our knowledge,new insights into mode manipulation methods in various applications.
基金This work was supported by the National Key R&D Program of China(Nos.2016YFA0202900 and 2016YFC1402400)National Natural Science Foundation of China(No.51672173)+2 种基金Shanghai Science and Technology committee(No.17JC1400700 and 18520744700)Science and Technology Planning Project of Guangdong Province(No.2016A010103018)The authors gratefully acknowledge the Shanghai Synchrotron Radiation Facility(SSRF)and Shanghai LEVSON Group Co.,Ltd.for the measurements.
文摘A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently.A low in put voltage is essential to en sure the heaters safe applications.However,the low voltage gen erally leads to low saturated temperature and heati ng rate and hence a low thermal efficie ncy.How to reduce the in put voltage while maintai ning a high electro-thermal efficiency is still a challenge.Herein,a highly electrical and thermal conductive film was 8nstructed using a graphene-based composite which has an internal three-dimensional(3D)conductive network.In the 3D framework,cellulose nanocrystalline(CNC)phase with chiral liquid crystal manner presents in the form of alig ned helix betwee n the graphe ne oxide(GO)layers.Carbon nano dots(CDs)are assembled泊side the composite as con ductive nano fillers.Subseque nt an neali ng and compressi on results in the formati on of the assembled GO-CNC-CDs film.The carb on ized CNC nano rods(CNR)with the helical alignment act as irrplane and through-pla ne conn ecti ons of n eighbori ng reduced GO(rGO)nano sheets,forming a con ductive network in the composite film.The CDs with ultrafast electr ons tran sfer rates provide additi onal electro ns and phonons tran sport paths for the composite.As a result,the obtai ned graphe ne?based composite film(rGO-CNR-CDs)exhibited a high thermal conductivity of 1,978.6 W m^-1·K^-1 and electrical conductivity of 2,053.4 S·cm^-1,respectively.The composite film showed an outstanding electro-thermal heating efficiency with the saturated temperature of 315℃and maximum heating rate of 44.9℃·s^-1 at a very low in put voltage of 10 V.The freestandi ng graphe ne composite film with the delicate nano structure desig n has a great pote ntial to be integrated into electro-thermal devices.
基金funded by National Natural Science Foundation of China(No.31970591 to H.Ma)the Shanghai Pujiang program(19PJ1408000 to H.Ma)Shanghai Science and Technology Innovation Action Plan(21JC1404800 to H.Ma).
文摘Dear Editor,Most human genetic diseases arise from mutations such as insertion,deletion,or point mutations(Landrum et al.,2016).CRISPRCas system has been repurposed to correct pathogenic mutations in a variety of genetic diseases(Choi et al.,2022).There are many concerns about using CRISPR-mediated double-stranded DNA breaks(DSBs)for therapeutic purposes,primarily due to off-targeted mutations(Kosicki et al.,2018).Nevertheless,base editing cannot correct deletions,insertions,or some point mutations such as transversion mutations.Prime editing has its advantages of precisely correct point mutations,small insertions,or deletions in animal cells(Anzalone et al.,2019)and plants(Lin et al.,2020).However,prime editing efficiency varies among genomic sites or cell types(Chen et al.,2021;Nelson et al.,2022).