Influence of spinal cord injury on core regions of motor function

Functional electrical stimulation is an effective way to rebuild hindlimb motor function after spinal cord injury.However,no site map exists to serve as a reference for implanting stimulator electrodes.In this study,rat models of thoracic spinal nerve 9 contusion were established by a heavy-impact method and rat models of T6/8/9 spinal cord injury were established by a transection method.Intraspinal microstimulation was performed to record motion types,site coordinates,and threshold currents induced by stimulation.After transection(complete injury),the core region of hip flexion migrated from the T13 to T12 vertebral segment,and the core region of hip extension migrated from the L1 to T13 vertebral segment.Migration was affected by post-transection time,but not transection segment.Moreover,the longer the post-transection time,the longer the distance of migration.This study provides a reference for spinal electrode implantation after spinal cord injury.This study was approved by the Institutional Animal Care and Use Committee of Nantong University,China(approval No.20190225-008)on February 26,2019.

Single-cell transcriptomic analysis identifies a highly replicating Cd168+ þskeletal stem/progenitor cell population in mouse long bones

Skeletal stem/progenitor cells(SSPCs)are tissue-specific stem/progenitor cells localized within skeletons and contribute to bone development,homeostasis,and regeneration.However,the heterogeneity of SSPC populations in mouse long bones and their respective regenerative capacity remain to be further clarified.In this study,we perform integrated analysis using single-cell RNA sequencing(scRNA-seq)datasets of mouse hindlimb buds,postnatal long bones,and fractured long bones.Our analyses reveal the heterogeneity of osteochondrogenic lineage cells and recapitulate the developmental trajectories during mouse long bone growth.In addition,we identify a novel Cd168þSSPC population with highly replicating capacity and osteochondrogenic potential in embryonic and postnatal long bones.Moreover,the Cd168þSSPCs can contribute to newly formed skeletal tissues during fracture healing.Furthermore,the results of multicolor immunofluorescence show that Cd168þSSPCs reside in the superficial zone of articular cartilage as well as in growth plates of postnatal mouse long bones.In summary,we identify a novel Cd168þSSPC population with regenerative potential in mouse long bones,which adds to the knowledge of the tissuespecific stem cells in skeletons.

Effective electrocatalytic hydrodechlorination of 2,4,6-trichlorophenol by a novel Pd/MnO_(2)/Ni foam cathode

Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO_(2) to realize optimal dechlorination efficiency at minimum cost.Here,a Pd/MnO_(2)/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58%in 180 min)was obtained when the concentration of PdCl_(2) precipitation was 1 mmol/L,the deposition time of MnO_(2) was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous factors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6%~47.6%)was observed in presence of 5 mmol/L of NO_(2)^(-),NO_(3)^(-),S^(2-)or SO_(3)^(2-).Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H^(*)_(ads)),absorbed atomic hydrogen(H^(*)_(abs)),and molecular hydrogen(H_(2)).And the introduction of MnO_(2)promoted the generation of atomic H^(*).Only adsorbed atomic hydrogen(H^(*)_(ads)) was confirmed that it truly facilitated the ECH process.Besides H^(*)_(ads) induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO_(2)/Ni foam cathode shows excellent dechlorination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.

Fisl phosphorylation by Met promotes mitochondrial fission and hepatocellular carcinoma metastasis

Met tyrosine kinase,a receptor for a hepatocyte growth factor(HGF),plays a critical role in tumor growth,metastasis,and drug resistance.Mitochondria are highly dynamic and undergo fission and fusion to maintain a functional mitochondrial network.Dysregulated mitochondrial dynamics are responsible for the progression and metastasis of many cancers.Here,using structured illumination microscopy(SIM)and high spatial and temporal resolution live cell imaging,we identified mitochondrial trafficking of receptor tyrosine kinase Met.The ton tacts betwee n activated Met kinase and mitochondria formed dramatically,and an intact HGF/Met axis was necessary for dysregulated mitochondrial fission and cancer cell movements.Mechanically,we found that Met directly phosphorylated outer mitochondrial membrane protein Fis1 at Tyr38(Fisl pY38).Fisl pY38 promoted mitochondrial fission by recruiting the mitochondrial fission GTPase dynamin-related protein・1(Drp1)to mitochondria.Fragmented mitochondria fueled actin filament remodeling and lamellipodia or invadopodia formation to facilitate cell metastasis in hepatocellular carcinoma(HCC)cells both in vitro and in vivo.These findings reveal a novel and noncanonical pathway of Met receptor tyrosine kinase in the regulation of mitochondrial activities,which may provide a therapeutic target for metastatic HCC.

Ordered mesoporous carbon as an efficient heterogeneous catalyst to activate peroxydisulfate for degradation of sulfadiazine

Catalytic potential of carbon nanomaterials in peroxydisulfate(PDS)advanced oxidation systems for degradation of antibiotics remains poorly understood.This study revealed ordered mesoporous carbon(type CMK)acted as a superior catalyst for heterogeneous degradation of sulfadiazine(SDZ)in PDS sys-tem,with a first-order reaction kinetic constant(k)and total organic carbon(TOC)mineralization efficiency of 0.06 min^(–1) and 59.67%±3.4%within 60min,respectively.CMK catalyzed PDS system exhibited high degradation efficiencies of five other sulfonamides and three other types of antibiotics,verifying the broad-degradation capacity of antibiotics.Under neutral pH conditions,the optimal catalytic parameters were an initial SDZ concentration of 44.0mg/L,CMK dosage of 0.07g/L,and PDS dosage of 5.44mmol/L,respectively.X-ray photoelectron spectroscopy and Raman spectrum analysis confirmed that the defect structure at edge of CMK and oxygen-containing functional groups on surface of CMK were major active sites,contributing to the high catalytic activity.Free radical quenching analysis revealed that both SO_(4)•−and•OH were generated and participated in catalytic reaction.In addition,direct electron transfer by CMK to activate PDS also occurred,further promoting catalytic performance.Configuration of SDZ molecule was optimized using density functional theory,and the possible reaction sites in SDZ molecule were calculated using Fukui function.Combining ultra-high-performance liquid chromatography(UPLC)–mass spectrometry(MS)/MS analysis,three potential degradation pathways were proposed,including the direct removal of SO_(2)molecules,the 14S-17N fracture,and the 19C-20N and 19C-27N cleavage of the SDZ molecule.The study demonstrated that ordered mesoporous carbon could work as a feasible catalytic material for PDS advanced oxidation during removal of antibiotics from wastewater.