MSC-derived exosomes attenuate hepatic fibrosis in primary sclerosing cholangitis through inhibition of Th17 differentiation

Primary sclerosing cholangitis(PSC)is an autoimmune cholangiopathy characterized by chronic inflammation of the biliary epithelium and periductal fibrosis,with no curative treatment available,and liver transplantation is inevitable for end-stage patients.Human placentalmesenchymal stem cell(hpMSC)-derived exosomes have demonstrated the ability to prevent fibrosis,inhibit collagen production and possess immunomodulatory properties in autoimmune liver disease.Here,we prepared hpMSC-derived exosomes(Exo^(MSC))and further investigated the anti-fibrotic effects and detailed mechanism on PSC based on Mdr2^(−/−)mice and multicellular organoids established from PSC patients.The results showed that Exo^(MSC) ameliorated liver fibrosis in Mdr2^(−/−)mice with significant collagen reduction in the preductal area where Th17 differentiation was inhibited as demonstrated by RNAseq analysis,and the percentage of CD4+IL-17A+T cells was reduced both in Exo^(MSC)-treated Mdr2^(−/−)mice(Mdr2^(−/−)-Exo)in vivo and Exo^(MSC)-treated Th17 differentiation progressed in vitro.Furthermore,Exo^(MSC) improved the hypersecretory phenotype and intercellular interactions in the hepatic Th17 microenvironment by regulating PERK/CHOP signaling as supported by multicellular organoids.Thus,our data demonstrate the antifibrosis effect of Exo^(MSC) in PSC disease by inhibiting Th17 differentiation,and ameliorating the Th17-induced microenvironment,indicating the promising potential therapeutic role of Exo^(MSC) in liver fibrosis of PSC or Th17-related diseases.

Audio-Text Multimodal Speech Recognition via Dual-Tower Architecture for Mandarin Air Traffic Control Communications

In air traffic control communications (ATCC), misunderstandings between pilots and controllers could result in fatal aviation accidents. Fortunately, advanced automatic speech recognition technology has emerged as a promising means of preventing miscommunications and enhancing aviation safety. However, most existing speech recognition methods merely incorporate external language models on the decoder side, leading to insufficient semantic alignment between speech and text modalities during the encoding phase. Furthermore, it is challenging to model acoustic context dependencies over long distances due to the longer speech sequences than text, especially for the extended ATCC data. To address these issues, we propose a speech-text multimodal dual-tower architecture for speech recognition. It employs cross-modal interactions to achieve close semantic alignment during the encoding stage and strengthen its capabilities in modeling auditory long-distance context dependencies. In addition, a two-stage training strategy is elaborately devised to derive semantics-aware acoustic representations effectively. The first stage focuses on pre-training the speech-text multimodal encoding module to enhance inter-modal semantic alignment and aural long-distance context dependencies. The second stage fine-tunes the entire network to bridge the input modality variation gap between the training and inference phases and boost generalization performance. Extensive experiments demonstrate the effectiveness of the proposed speech-text multimodal speech recognition method on the ATCC and AISHELL-1 datasets. It reduces the character error rate to 6.54% and 8.73%, respectively, and exhibits substantial performance gains of 28.76% and 23.82% compared with the best baseline model. The case studies indicate that the obtained semantics-aware acoustic representations aid in accurately recognizing terms with similar pronunciations but distinctive semantics. The research provides a novel modeling paradigm for semantics-aware speech recognition in air traffic control communications, which could contribute to the advancement of intelligent and efficient aviation safety management.

“双一流”建设背景下科教融合实验教学探索--以TiO_(2)光催化降解染料废水实验为例

科教融合的办学理念已经成为“双一流”建设高校科教并重发展的必然选择。将瞬时纳米沉降技术制备多孔TiO_(2)纳米球及其光催化降解染料的研究引入本科教学中,例如大学生研究训练计划(SRP)项目。该综合实验设计内容符合科教融合的发展需求,通过该实验,有助于加深学生对知识点的综合理解,培养学生的创新能力和实践能力。

Mn-based MXene with high lithium-ion storage capacity

3d-transition metal(Fe,Co,Ni,and Mn)-based MXene materials have been predicted to demonstrate exceptional electrochemical performance because of their good electrical conductivity and the presence of metallic atoms with multiple charge states.However,until now,there have been no reports on MXenes based on Fe,Co,Ni,and Mn,due to the lack of 3d-metal-layered precursors.Herein,we successfully synthesized the first 3d-transition metal-based MXenes,Mn_(2)CT_(x) by exfoliating a layered precursor derived from the anti-perovskite bulk Mn3GaC.The as-prepared Mn_(2)CT_(x) MXene nanosheets were employed as anode materials in lithium-ion batteries,which exhibited stable storage capacity of 764.7 mAh·g^(-1) at 0.5 C,placing its storage capacities at an upper-middle level compared with other reported MXene materials as well as other Mn-based anode materials.Overall,this study opens a new avenue for MXene research by synthesizing 3d-transition metal-based MXenes for electrochemical applications.

Human Placental Mesenchymal Stem Cells Relieve Primary Sclerosing Cholangitis via Upregulation of TGR5 in Mdr2^(-/-)Mice and Human Intrahepatic Cholangiocyte Organoid Models

Primary sclerosing cholangitis(PSC)is a biliary disease accompanied by chronic inflammation of the liver and biliary stricture.Mesenchymal stem cells(MSCs)are used to treat liver diseases because of their immune regulation and regeneration-promoting functions.This study was performed to explore the therapeutic potential of human placental MSCs(hP-MSCs)in PSC through the Takeda G protein-coupled receptor 5(TGR5)receptor pathway.Liver tissues were collected from patients with PSC and healthy donors(n=4)for RNA sequencing and intrahepatic cholangiocyte organoid construction.hP-MSCs were injected via the tail vein into Mdr2^(-/-),bile duct ligation(BDL),and 3,5-diethoxycarbonyl-1,4-dihydrocollidine(DDC)mouse models or co-cultured with organoids to confirm their therapeutic effect on biliary cholangitis.Changes in bile acid metabolic profile were analyzed by liquid chromatography/tandem mass spectrometry(LC-MS/MS).Compared with healthy controls,liver tissues and intrahepatic cholangiocyte organoids from PSC patients were characterized by inflammation and cholestasis,and marked downregulation of bile acid receptor TGR5 expression.hP-MSC treatment apparently reduced the inflammation,cholestasis,and fibrosis in Mdr2^(-/-),BDL,and DDC model mice.By activating the phosphatidylinositol 3 kinase/extracellular signal-regulated protein kinase pathway,hP-MSC treatment promoted the proliferation of cholangiocytes,and affected the transcription of downstream nuclear factorκB through regulation of the binding of TGR5 and Pellino3,thereby affecting the cholangiocyte inflammatory phenotype.

Flame-retardant quasi-solid polymer electrolyte enabling sodium metal batteries with highly safe characteristic and superior cycling stability

Con ventio nal liquid electrolytes based sodium metal batteries suffer from severe safety hazards owing to electrolyte leakage,in flammability and dendritic sodium deposit!on.Herein,we report a flame-retardant quasi-solid polymer electrolyte with poly(methyl vinyl ether-alt-maleic an hydride)(P(MVE-alt-MA))as host,bacterial cellulose(BC)as reinforceme nt,and triethyl phosphate/vinyle ne carb on ate/sodium perchlorate(TEP/VC/NaClO4)as plasticizer for highly safe sodium metal batteries.The as-obtained quasi-solid polymer electrolyte exhibits superior flame retardancy(self-extinguish within 1 s),complete non-leakage property and wide electrochemical windows(4.4 V).More importantly,Na3V2(PO4)3/Na metal batteries using such polymer electrolyte delivers superior I on g-term cycli ng stability(84.4%capacity rete ntion after 1000 cycles)which is significantly better than that(only 2%after 240 cycles)of liquid electrolyte.In addition,this flame-retardant quasi-solid polymer electrolyte provides favorable cycle performance(80.2%capacity retention after 70 cycles at 50°C and 84.8%capacity retention after 50 cycles at-10°C)for Na3V2(PO4)3/Na metal batteries.And this battery also displayed a normal charge/discharge property even at-15°C.These fascinating cycle properties are mainly ascribed to the effective pro怕ctive layers formed on Na3V2(PC>4)3 cathode and sodium metal ano de.More thorough in vestigati on elucidates that such flame-retardant quasi-solid polymer electrolyte plays a multif unctional role in the adva need sodium metal batteries:(1)being in volved in the formatio n of a favorable cathode electrolyte in terface(CEI)to inhibit the dissolutio n of van adium and maintai n the structure integrity of the Na3V2(PO4)3;(2)participati ng in building a stable solid electrolyte in terface(SEI)to suppress the growth of Na dendrites;(3)integrating flame-retardanee into polymer sodium batteries to enhance flame-resistanee,eliminate electrolyte leakage,and thus improve safety of sodium batteries.Based on these results,we further assembled Na3V2(PO4)3/MoS2 pouch cell which can withsta nd harsh conditions(be nded or cut off a corn er),confirming the obtai ned polymer electrolyte with superior non-leakage property.In all,these outstanding characteristics would endow this flame-retardant quasi-solid polymer electrolyte a very promising can didate for highly-safe sodium metal batteries.

Intelligent checking model of Chinese radiotelephony read-backs in civil aviation air traffic control

Federal Aviation Administration(FAA) and NASA technical reports indicate that the misunderstanding in radiotelephony communications is a primary causal factor associated with operation errors, and a sizable proportion of operation errors lead to read-back errors. We introduce deep learning method to solve this problem and propose a new semantic checking model based on Long Short-Time Memory network(LSTM) for intelligent read-back error checking. A meanpooling layer is added to the traditional LSTM, so as to utilize the information obtained by all the hidden activation vectors, and also to improve the robustness of the semantic vector extracted by LSTM. A MultiLayer Perceptron(MLP) layer, which can maintain the information of different regions in the concatenated vectors obtained by the mean-pooling layer, is applied instead of traditional similarity function in the new model to express the semantic similarity of the read-back pairs quantitatively. The K-Nearest Neighbor(KNN) classifier is used to verify whether the read-back pairs are consistent in semantics according to the output of MLP layer. Extensive experiments are conducted and the results show that the proposed model is more effective and more robust than the traditional checking model to verify the semantic consistency of read-backs automatically.

Combined application of biochar with fertilizer promotes nitrogen uptake in maize by increasing nitrogen retention in soil

Combined application of biochar with fertilizers has been used to increase soil fertility and crop yield.However,the coupling mechanisms through which biochar improves crop yield at field scale and the time span over which biochar affects carbon and nitrogen transformation and crop yield are still little known.In this study,a long-term field trial(2013-2019)was performed in brown soil planting maize.Six treatments were designed:CK-control;NPK-application of chemical fertilizers;C1PK-low biochar without nitrogen fertilizer;C1NPK,C_(2)NPK and C_(3)NPK-biochar at 1.5,3 and 6 t ha^(−1),respectively,combined with chemical fertilizers.Results showed that theδ^(15)N value in the topsoil of 0-20 cm layer in the C_(3)NPK treat-ment reached a peak of 291‰at the third year(2018),and demonstrated a peak of 402‰in the NPK treatment in the initial isotope trial in 2016.Synchronously,SOC was not affected until the third to fourth year after biochar addition,and resulted in a significant increase in total N of 2.4 kg N ha^(−1) in 2019 in C_(3)NPK treatment.During the entire experiment,the ^(15)N recovery rates of 74-80%were observed highest in the C_(2)NPK and C_(3)NPK treatments,resulting in an annual increase in yields significantly.The lowest subsoilδ^(15)N values ranged from 66‰to 107‰,and the ^(15)N residual rate would take 70 years for a complete decay to 0.001%in the C_(3)NPK.Our findings suggest that biochar compound fertilizers can increase C stability and N retention in soil and improve N uptake by maize,while the loss of N was minimized.Biochars,therefore,may have an important potential for improving the agroecosystem and ecological balance.

Biochar-induced changes in the soil diazotroph community abundance and structure in a peanut field trial

Biological nitrogen fixation(BNF)can help replenish available nitrogen(N)in cropland and reduce the use of chemical N fertilizers,with diazotrophs playing an important role.However,the response of diazotroph community and BNF activity in biochar amendment soil,especially in the deep soil horizon,are poorly understood.In this study,soil samples were collected from topsoil(0-20 cm)and subsoil(20-40 cm)in the field experiment(established in 2013)comprising treatments with no chemical fertilizer(CK),chemical fertilizer(NPK),biochar(BC),and biochar plus chemical fertilizers(BNPK).Here,we investigated the diazotroph community using real-time PCR and high-throughput sequencing of the nifH gene,and assessed the soil N_(2)fixation rate(R_(Nfix))using acetylene reduction assay(ARA).Results showed that in the topsoil,the treatments with biochar significantly increased nifH gene copies and R_(Nfix),which was consistent with the increased soil organic matter(SOM),total carbon-to-nitrogen ratio(C/N),dissolved organic carbon(DOC)and pH.In the subsoil,applying chemical fertilizers(NPK)strongly decreased R_(Nfix),but had no effect on diazotroph abundance;in contrast,biochar application(BC)had no effect on R_(Nfix),but suppressed the growth of bacteria and diazotrophs while increasing the abundance of Rhizobiales order.Diazotroph and bacterial gene copies were significantly and positively correlated in both top-and sub-soil,and they were mainly influenced by SOM and total nitrogen(TN).In addition,soil nitrate nitrogen(NO_(3)^(−)-N)was the major factor in shaping the vertical stratification of diazotroph community structure.Although nifH gene abundance was significantly cor-related with R_(Nfix)in the topsoil,the structure equation modeling(SEM)showed the highest correlation between diazotroph community structure and R_(Nfix).Hence,we suggested that soil carbon and nitrogen sources were the key factors correlated with changes in the vertical pattern of diazotroph abundance.Biochar induced the dominant diazotroph community succes-sion and increased soil carbon content and pH,which contributed to the BNF activity.Changes in the BNF activity were driven by the variation in diazotroph community structure.

Reliable and broad-range layer identification of Au-assisted exfoliated large area MoS_(2)and WS_(2)using reflection spectroscopic fingerprints

The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional(2D)crystals.Fast,damage-free,and reliable determination of the layer number of such 2D films can greatly promote layer-dependent physical studies and device applications.Here,an optical method has been developed for simple,high throughput,and accurate determination of the layer number for Au-assisted exfoliated MoS_(2)and WS_(2)films in a broad thickness range.The method is based on quantitative analysis of layer-dependent white light reflection spectra(WLRS),revealing that the intensity of exciton-induced reflection peaks can be used as a clear indicator for identifying the layer number.The simple yet robust method will facilitate fundamental studies on layer-dependent optical,electrical,and thermal properties and device applications of 2D materials.The technique can also be readily combined with photoluminescence(PL)and Raman spectroscopies to study other layer-dependent physical properties of 2D materials.

A luminescence molecular switch via modulation of PET and ICT processes in DCM system

A novel versatile dicyanomethylene-4H-pyran （DCM） based derivative bearing ferrocenyl group （DCM-N-Fc） is designed as modulator to construct ＂off-on＂ logic operation. The optical properties of DCM-N-Fc are characterized by absorption and steady-state fluorescence technique, showing that the fluorescence from DCM ehromophore via intramolecular charge transfer （ICT） is strongly quenched by photoinduced electron transfer （PET） process from ferrocene moiety. In contrast with the references （DCM-N and DCM-Fc）, the fluorescence of DCM-N-Fc can be triggered by oxidizing ferrocenyl unit either chemically or electrochemically, exhibiting a characteristic emission modulation at around 610 nm with an electrofluorochromic behavior. Furthermore, the free energy and the fluorescence lifetime in the PET path verify the thermodynamic feasibility. Cyclic voltammetry, absorption spectroscopy, time-resolved fluorescence as well as DFT calculation have been used to elaborate the manipulation via both PET and ICT processes.