Construction of V2O5@MXene Cathodes toward a High Specific Capacity Aqueous Aluminum-Ion Battery.

Aqueous aluminum-ion batteries (AAIBs) are considered a strong candidate for the new generation of energy storage devices. The lack of suitable cathode materials has been a bottleneck factor hindering the future development of AAIBs. In this work, we design and construct a highly effective cathode with dual morphologies. Two-dimensional (2D) layered MXene materials possessed good conductivity and hydrophilicity, which are used as the substrates to deposit rod-shaped vanadium oxides (V2O5) to form a three-dimensional (3D) cathode. The cathode design provides a strong boost for the rapid electrochemical activities of rod-shaped V2O5 by embedding/extracting both protons (H+) and aluminum-ion (Al3+). As a result, the V2O5@MXene cathode based AAIB delivers an ultrahigh initial specific capacity of 626 mAh/g at 0.1 A/g with a stable cycle performance up to 100 cycles. This work is a breakthrough for the development of cathode materials for AAIBs.

Programmed Remodeling of the Tumor Milieu to Enhance NK Cell Immunotherapy Combined with Chemotherapy for Pancreatic Cancer.

Natural killer (NK) cell-based adoptive immunotherapy has demonstrated encouraging therapeutic effects in clinical trials for hematological cancers. However, the effectiveness of treatment for solid tumors remains a challenge due to insufficient recruitment and infiltration of NK cells into tumor tissues. Herein, a programmed nanoremodeler (DAS@P/H/pp) is designed to remodel dense physical stromal barriers and for dysregulation of the chemokine of the tumor environment to enhance the recruitment and infiltration of NK cells in tumors. The DAS@P/H/pp is triggered by the acidic tumor environment, resulting in charge reversal and subsequent hyaluronidase (HAase) release. HAase effectively degrades the extracellular matrix, promoting the delivery of immunoregulatory molecules and chemotherapy drugs into deep tumor tissues. In mouse models of pancreatic cancer, this nanomediated strategy for the programmed remodeling of the tumor microenvironment significantly boosts the recruitment of NK92 cells and their tumor cell-killing capabilities under the supervision of multiplexed near-infrared-II fluorescence.

Designable Nanoadaptor for Enhanced Recognition of Natural Killer Cell to Tumor via Bio-orthogonal Click Reaction.

Highly efficient recognition of cancer cells by immune cells is important for successful therapeutic-cell-based cancer immunotherapy. Herein, we present a facile NIR-II nanoadaptor [hyaluronic acid (HA)/dibenzocyclooctyne (DBCO)-Au:Ag2Te quantum dots (QDs)] for enhancing the tumor recognition and binding ability of natural killer (NK) cells via a bio-orthogonal click reaction in vivo. The Nanoadaptor possesses superior tumor-targeting capacity, facilitating the accumulation of the chemical receptor DBCO at the tumor sites. Subsequently, the enrichment of DBCO on tumor cell surfaces provides multivalent recognition sites for capturing pretreated azide engineered NK92 cells (NK92-N3) through an efficient click reaction, thereby significantly enhancing the therapeutical efficiency. The dynamic process of nanoadaptor-mediated recognition of NK cells to tumor cells could be vividly observed using multiplexed NIR-II fluorescence imaging in a mouse model of lung cancer. Such a nanoadaptor strategy can be extended to other therapeutic cellular systems and holds promise for future clinical applications.

Functional analysis of a wheat class III peroxidase gene, TaPer12-3A, in seed dormancy and germination.

BACKGROUND: Class III peroxidases (PODs) perform crucial functions in various developmental processes and responses to biotic and abiotic stresses. However, their roles in wheat seed dormancy (SD) and germination remain elusive. RESULTS: Here, we identified a wheat class III POD gene, named TaPer12-3A, based on transcriptome data and expression analysis. TaPer12-3A showed decreasing and increasing expression trends with SD acquisition and release, respectively. It was highly expressed in wheat seeds and localized in the endoplasmic reticulum and cytoplasm. Germination tests were performed using the transgenic Arabidopsis and rice lines as well as wheat mutant mutagenized with ethyl methane sulfonate (EMS) in Jing 411 (J411) background. These results indicated that TaPer12-3A negatively regulated SD and positively mediated germination. Further studies showed that TaPer12-3A maintained H2O2 homeostasis by scavenging excess H2O2 and participated in the biosynthesis and catabolism pathways of gibberellic acid and abscisic acid to regulate SD and germination. CONCLUSION: These findings not only provide new insights for future functional analysis of TaPer12-3A in regulating wheat SD and germination but also provide a target gene for breeding wheat varieties with high pre-harvest sprouting resistance by gene editing technology.

α-MnO2 Cathode with Oxygen Vacancies Accelerated Affinity Electrolyte for Dual-Ion Co-Encapsulated Aqueous Aluminum Ion Batteries.

Aluminum batteries (ABs) are identified as one of the most promising candidates for the next generation of large-scale energy storage elements because of their efficient three-electron reaction. Compared to ionic electrolytes, aqueous aluminum-ion batteries (AAIBs) are considered safer, less costly, and more environmentally friendly. However, considerable cycling performance is a key issue limiting the development of AAIBs. Stable, efficient, and electrolyte-friendly cathodes are most desirable for AAIBs. Herein, a rod-shaped defect-rich α-MnO2 is designed as a cathode, which is capable to deliver high performance with stable cycling for 180 cycles at 500 mA g-1 and maintains a discharge specific capacity of ≈100 mAh g-1. In addition, the infiltrability simulation is effectively utilized to corroborate the rapid electrochemical reaction brought about by the defective mechanism. With the formation of oxygen vacancies, the dual embedding of protons and metal ions is activated. This work provides a brand-new design for the development and characterization of cathodes for AAIBs.

Analysis of the impact of temperature on the spectral shift in ultraviolet hyperspectral imaging spectrometers.

The imaging spectrometer's high performance in practical applications may be compromised by environmental factors, particularly temperature variations, posing a challenge to its stability. Temperature fluctuations can induce spectral shift, directly impacting the accuracy of spectral measurements, subsequently influencing the precision of radiometric measurements. To address this issue, this study investigates a dual-channel UV imaging spectrometer. This instrument boasts a wavelength calibration accuracy of 0.01 nm. This paper conducts an in-depth analysis of the various mechanisms through which temperature changes influence the spectral line offset in the imaging spectrometer, integrating actual orbital temperature data to discuss the instrument's temperature load settings. The impact of temperature on spectral shift is examined using finite element analysis and optical design software. Estimations of spectral shift were made based on temperature variations. Simulation results indicated that the maximum deviation of spectral shift is estimated at 0.018 nm under a temperature condition of 16 ± 1°C. Under a more controlled orbital temperature condition (16 ± 0.3°C), the maximum deviation of spectral shift decreased to 0.01 nm. Experimental data revealed that at 16 ± 1°C, the maximum deviation of spectral shift did not exceed 0.01 nm. This effectively corroborates our theoretical analysis. The relationship between temperature and spectral shift offers a crucial theoretical foundation for calibrating spectral measurements and managing the thermal conditions of the instrument.

METTL14/YTHDF1 axis-modified UCHL5 aggravates atherosclerosis by activating the NLRP3 inflammasome.

BACKGROUND: Vascular smooth muscle cell (VSMC) phenotypic switching contributes to VSMC proliferation and migration in atherosclerosis (AS). Nevertheless, the regulatory mechanism of VSMC phenotypic switching during AS progression is unclear. Here, the role and regulatory mechanism of UCHL5 in VSMC phenotypic switching during AS progression were investigated. METHODS: ApoE-/- mice were fed with high fat diet to establish AS model in vivo. VSMCs stimulated by ox-LDL were used as AS cellular model. VSMC proliferation and migration were examined by CCK8 assay and transwell assay, respectively. The levels of pro-inflammatory cytokines were assessed using ELISA. The interactions between METTL14/YTHDF1, UCHL5 and NLRP3 were analyzed using RIP and/or dual-luciferase reporter gene and/or Co-IP assays. NLRP3 ubiquitination was analyzed by ubiquitination analysis. RESULTS: UCHL5 was significantly upregulated in AS patients and ox-LDL-treated VSMCs. UCHL5 silencing ameliorated plaque formation and vascular remodeling in vivo and suppressed ox-LDL-induced VSMC proliferation, migration, inflammation and phenotypic switching in vitro. Moreover, METTL14 could increase UCHL5 mRNA m6A level and promoted UCHL5 expression by recruiting YTHDF1. Moreover, UCHL5 overexpression enhanced protein stability by deubiquitinating NLRP3. Rescue studies revealed that NLRP3 overexpression abrogated UCHL5 silencing-mediated biological effects in ox-LDL-treated VSMCs. CONCLUSION: UCHL5 modified by METTL14/YTHDF1 axis could facilitate the inflammation and vascular remodeling in atherosclerosis by activating the NLRP3 inflammasome.

Aging affects auditory contributions to focus perception in Jianghuai Mandarina).

Speakers can place their prosodic prominence on any locations within a sentence, generating focus prosody for listeners to perceive new information. This study aimed to investigate age-related changes in the bottom-up processing of focus perception in Jianghuai Mandarin by clarifying the perceptual cues and the auditory processing abilities involved in the identification of focus locations. Young, middle-aged, and older speakers of Jianghuai Mandarin completed a focus identification task and an auditory perception task. The results showed that increasing age led to a decrease in listeners' accuracy rate in identifying focus locations, with all participants performing the worst when dynamic pitch cues were inaccessible. Auditory processing abilities did not predict focus perception performance in young and middle-aged listeners but accounted significantly for the variance in older adults' performance. These findings suggest that age-related deteriorations in focus perception can be largely attributed to declined auditory processing of perceptual cues. Poor ability to extract frequency modulation cues may be the most important underlying psychoacoustic factor for older adults' difficulties in perceiving focus prosody in Jianghuai Mandarin. The results contribute to our understanding of the bottom-up mechanisms involved in linguistic prosody processing in aging adults, particularly in tonal languages.

Oxygen Vacancies Boosted Proton Intercalation Kinetics for Aqueous Aluminum-Manganese Batteries.

Aluminum-ion batteries have garnered an extensive amount of attention due to their superior electrochemical performance, low cost, and high safety. To address the limitation of battery performance, exploring new cathode materials and understanding the reaction mechanism for these batteries are of great significance. Among numerous candidates, multiple structures and valence states make manganese-based oxides the best choice for aqueous aluminum-ion batteries (AAIBs). In this work, a new cathode consists of γ-MnO2 with abundant oxygen vacancies. As a result, the electrode shows a high discharge capacity of 481.9 mAh g-1 at 0.2 A g-1 and a sustained reversible capacity of 128.6 mAh g-1 after 200 cycles at 0.4 A g-1. In particular, through density functional theory calculation and experimental comparison, the role of oxygen vacancies in accelerating the reaction kinetics of H+ has been verified. This study provides insights into the application of manganese dioxide materials in aqueous AAIBs.

Co-Administration of nalbuphine to improve morphine tolerance in mice with bone cancer pain.

BACKGROUND: Kappa-opioid receptor (KOR) agonists are known for having opposite and/or different effects compared with Mu-opioid receptor (MOR) agonists. This study is aimed at clarifying the analgesic effect and tolerance of nalbuphine combined with morphine, and quantifying the mRNA and protein expression of spinal MOR and KOR in a mouse bone cancer pain (BCP) model treated with nalbuphine and morphine. METHOD: BCP model was prepared in C3H/HeNCrlVr Mice by implanting the sarcoma cells into the intramedullary space of the femur. The paw withdrawal thermal latency (PWL) measured by thermal radiometer was used to assess thermal hyperalgesia. PWL testing was performed after implantation and drug administration according to the protocol. Hematoxylin-eosin staining in the spinal cord and x-ray in the femoral intramedullary canal was detected. Real-time PCR and western blot analysis played a role in detecting spinal MOR and KOR expression changes. RESULTS: In tumor-implanted mice, the spinal MOR and KOR protein and mRNA expression was down-regulated when compared to that in sham-implanted mice (p < 0.05). Morphine therapy can lead to a decrease in spinal µ receptor expression. Similarly, the nalbuphine therapy can lead to a decrease in the expression of κ receptor protein and mRNA at the spinal cord level (p < 0.05). Morphine, nalbuphine, or nalbuphine co-administration with morphine all can extend the paw withdrawal thermal latency (PWL) to radiant thermal stimulation in tumor-implanted mice (p < 0.05). Compared with the morphine treatment group, nalbuphine co-administration with morphine delayed the reduction of PWL value again (p < 0.05). DISCUSSION: BCP itself may induce down-regulation of the spinal MOR and KOR expression. A low dose of nalbuphine co-administration with morphine led to the delayed emergence of morphine tolerance. The part of the mechanism may be due to the regulation of spinal opioid receptors expression.

Optimal time point of response assessment for predicting survival is associated with tumor burden in hepatocellular carcinoma receiving repeated transarterial chemoembolization.

OBJECTIVES: Objective response rate (ORR) under mRECIST criteria after transarterial chemoembolization (TACE) is a well-perceived surrogate endpoint of overall survival (OS). However, its optimal time point remains controversial and may be influenced by tumor burden. We aim to investigate the surrogacy of initial/best ORR in relation to tumor burden. METHODS: A total of 1549 eligible treatment-naïve patients with unresectable hepatocellular carcinoma (HCC), Child-Pugh score ≤ 7, and performance status score ≤ 1 undergoing TACE between January 2010 and May 2016 from 17 academic hospitals were retrospectively analyzed. Based on "six-and-twelve" criteria, tumor burden was graded as low, intermediate, and high if the sum of the maximum tumor diameter and tumor number was ≤ 6, > 6 but ≤ 12, and > 12, respectively. RESULTS: Both initial and best ORRs interacted with tumor burden. Initial and best ORRs could equivalently predict and correlate with OS in low (adjusted HR, 2.55 and 2.95, respectively, both p < 0.001; R = 0.84, p = 0.035, and R = 0.97, p = 0.002, respectively) and intermediate strata (adjusted HR, 1.81 and 2.22, respectively, both p < 0.001; R = 0.74, p = 0.023, and R = 0.9, p = 0.002, respectively). For high strata, only best ORR exhibited qualified surrogacy (adjusted HR, 2.61, p < 0.001; R = 0.70, p = 0.035), whereas initial ORR was not significant (adjusted HR, 1.08, p = 0.357; R = 0.22, p = 0.54). CONCLUSIONS: ORR as surrogacy of OS is associated with tumor burden. For patients with low/intermediate tumor burden, initial ORR should be preferred in its early availability upon similar sensitivity, whereas for patients with high tumor burden, best ORR has optimal sensitivity. Timing of OR assessment should be tailored according to tumor burden. KEY POINTS: • This is the first study utilizing individual patient data to comprehensively analyze the surrogacy of ORR with a long follow-up period. • Optimal timing of ORR assessment for predicting survival should be tailored according to tumor burden. • For patients with low and intermediate tumor burden, initial ORR is optimal for its timeliness upon similar sensitivity with best ORR. For patients with high tumor burden, best ORR has optimal sensitivity.

Elevated serum homocysteine levels are associated with the development of chronic venous ulcers.

INTRODUCTION: Venous ulceration is a multifactorial disease, and whether hyperhomocysteinemia (HHcy) promotes deterioration from primary varicose veins to venous ulcers remains unproven. METHODS: This study retrospectively analyzed clinical data from 717 patients to investigate the potential correlation between HHcy and primary varicose veins ulcer formation, including 611 patients without ulcers (control group) and 106 with ulcers (case group). RESULTS: In this study, 46.2% (49/106) of patients in the case group and 17.5% (107/611, p < 0.001) in the control group suffered from HHcy. Multivariate logistic analysis revealed that HHcy was closely associated with the incidence of venous ulceration in patients with primary varicose veins (p < 0.001). Propensity score matching created 101 matched pairs of patients with and without ulcers, and the analysis pointed to a potential link between HHcy and ulcer formation in the context of primary varicose veins (p < 0.001). Additional experiments showed that HHcy could induce endothelial dysfunction and phenotypic switching of vascular smooth muscle cells. CONCLUSION: Both clinical and experimental findings implicated HHcy as a key factor in the development of venous ulceration. Further research is needed to appraise the effectiveness of HHcy-lowering therapy in the prevention of venous ulcers in patients with varicose veins.

Activatable Rare Earth Near-Infrared-II Fluorescence Ratiometric Nanoprobes.

Rational design of efficient lanthanide-doped down-shifting nanoparticles (DSNPs) has attracted tremendous attention. However, energy loss was inevitable in the multiple Ln3+ doping systems owing to complex energy migration processes. Here, an efficient NaErF4@NaYF4@NaYF4:10%Nd@NaYF4 DSNP was tactfully designed, in which a buffer layer of NaYF4 was modulated to restrict the interionic energy migration between Er3+ and Nd3+; meanwhile, the surface defects were passivated by an outermost layer of NaYF4. Therefore, the as-prepared DSNPs exhibited two intensive near-infrared-II fluorescence emissions of 1525 nm from Er3+ and 1060 nm from doped Nd3+ under 808 nm excitation. Further, a novel ratiometric nanoprobe NaErF4@NaYF4@NaYF4:10%Nd@NaYF4@A1094 was fabricated by coupling an organic dye of A1094 onto the DSNP surface to quench the 1060 nm emission by the efficient Förster resonance energy transfer, while emission at 1525 nm retained. Thereafter, these activatable ratiometric nanoprobes were used for rapid and sensitive detection of peroxynitrite (ONOO-) in vivo.

Pb-Doped Ag2 Se Quantum Dots with Enhanced Photoluminescence in the NIR-II Window.

Ag2 Se quantum dots (QDs) as an effective biological probe in the second near-infrared window (NIR-II, 1000-1700 nm) have been widely applied in bioimaging with high tissue penetration depth and high spatiotemporal resolution. However, the ions deficiency and crystal defects caused by the high Ag+ mobility in Ag2 Se crystals are mainly responsible for the inefficient photoluminescence (PL) of Ag2 Se QDs. Herein, a tailored route is reported to achieve controllable doping of Ag2 Se QDs in which Ag is exchanged by Pb via cation exchange (CE), which is unattainable by direct synthetic methods. The Pb-doped Ag2 Se QDs (denoted as Pb:Ag2 Se QDs) present fire-new optical features with significantly enhanced PL intensity of 4.2 folds. Photoelectron spectroscopy confirms that Pb acts as an n-type dopant for Ag2 Se QDs and therefore the electronic impurities provide additional carriers to fill the traps. Moreover, the general validity of this method is demonstrated to convert different sized Ag2 Se into Pb:Ag2 Se QDs, so that a wide range of NIR-II PL with high intensity is obtained. The bright NIR-II emission of Pb:Ag2 Se QDs is further successfully performed in lymphatic system mapping.

Ultrahigh-charge electron beams from laser-irradiated solid surface.

Compact acceleration of a tightly collimated relativistic electron beam with high charge from a laser-plasma interaction has many unique applications. However, currently the well-known schemes, including laser wakefield acceleration from gases and vacuum laser acceleration from solids, often produce electron beams either with low charge or with large divergence angles. In this work, we report the generation of highly collimated electron beams with a divergence angle of a few degrees, nonthermal spectra peaked at the megaelectronvolt level, and extremely high charge (∼100 nC) via a powerful subpicosecond laser pulse interacting with a solid target in grazing incidence. Particle-in-cell simulations illustrate a direct laser acceleration scenario, in which the self-filamentation is triggered in a large-scale near-critical-density plasma and electron bunches are accelerated periodically and collimated by the ultraintense electromagnetic field. The energy density of such electron beams in high-Z materials reaches to [Formula: see text], making it a promising tool to drive warm or even hot dense matter states.

Exosomes derived from mmu_circ_0000250-modified adipose-derived mesenchymal stem cells promote wound healing in diabetic mice by inducing miR-128-3p/SIRT1-mediated autophagy.

More and more evidence advises that circular RNAs (circRNAs) function critically in regulating different disease microenvironments. Our previous study found that autotransplantation of adipose-derived mesenchymal stem cells (ADSCs) promotes diabetes wound healing. Exosomes derived in ADSCs play an important regulatory role. This study aimed to characterize if mmu_circ_0000250 played a role in ADSC-exosome-mediated full-thickness skin wound repair in diabetic rats. Endothelial progenitor cells (EPCs) were selected to study the therapeutic mechanism of exosomes in high-glucose (HG)-induced cell damage and dysfunction. Analysis and luciferase reporter assay were utilized to explore the interaction among mmu_circ_0000250, miRNA (miR)-128-3p, and sirtuin (SIRT)1. The diabetic rats were used to confirm the therapeutic effect of mmu_circ_0000250 against exosome-mediated wound healing. Exosomes containing a high concentration of mmu_circ_0000250 had a greater therapeutic effect on restoration of the function of EPCs by promotion autophagy activation under HG conditions. Expression of mmu_circ_0000250 promoted SIRT1 expression by miR-128-3p adsorption, which was confirmed via luciferase reporter assay and bioinformatics analysis. In vivo, exosomes containing a high concentration of mmu_circ_0000250 had a more therapeutic effect on wound healing when compared with wild-type exosomes from ADSCs. Immunohistochemistry and immunofluorescence detection showed that mmu_circ_0000250 increased angiopoiesis with exosome treatment in wound skin and suppressed apoptosis by autophagy activation. In conclusion, we verified that mmu_circ_0000250 enhanced the therapeutic effect of ADSC-exosomes to promote wound healing in diabetes by absorption of miR-128-3p and upregulation of SIRT1. Therefore, these findings advocate targeting the mmu_circ_0000250/miR-128-3p/SIRT1 axis as a candidate therapeutic option for diabetic ulcers.

Controlled Synthesis of Ag2 Te@Ag2 S Core-Shell Quantum Dots with Enhanced and Tunable Fluorescence in the Second Near-Infrared Window.

Fluorescence in the second near-infrared window (NIR-II, 900-1700 nm) has drawn great interest for bioimaging, owing to its high tissue penetration depth and high spatiotemporal resolution. NIR-II fluorophores with high photoluminescence quantum yield (PLQY) and stability along with high biocompatibility are urgently pursued. In this work, a Ag-rich Ag2 Te quantum dots (QDs) surface with sulfur source is successfully engineered to prepare a larger bandgap of Ag2 S shell to passivate the Ag2 Te core via a facile colloidal route, which greatly enhances the PLQY of Ag2 Te QDs and significantly improves the stability of Ag2 Te QDs. This strategy works well with different sized core Ag2 Te QDs so that the NIR-II PL can be tuned in a wide range. In vivo imaging using the as-prepared Ag2 Te@Ag2 S QDs presents much higher spatial resolution images of organs and vascular structures as compared with the same dose of Ag2 Te nanoprobes administrated, suggesting the success of the core-shell synthetic strategy and the potential biomedical applications of core-shell NIR-II nanoprobes.

Betatron radiation polarization control by using an off-axis ionization injection in a laser wakefield acceleration.

Tunable X-ray sources from a laser-driven wakefield have wide applications. However, due to the difficulty of electron dynamics control, currently the tunability of laser wakefield-based X-ray sources is still difficult. By using three-dimensional particle-in-cell simulations, we propose a scheme to realize controllable electron dynamics and X-ray radiation. In the scheme, a long wavelength drive pulse excites a plasma wake and an off-axis laser pulse with a short wavelength co-propagates with the drive pulse and ionizes the K-shell electrons of the background high-Z gas. The electrons can be injected in the wakefield with controllable transverse positions and residual momenta. These injected electrons experience controllable oscillations in the wake, leading to tunable radiations both in intensity and polarization.

Probing Primordial Chirality with Galaxy Spins.

Chiral symmetry is maximally violated in weak interactions [1], and such microscopic asymmetries in the early Universe might leave observable imprints on astrophysical scales without violating the cosmological principle. In this Letter, we propose a helicity measurement to detect primordial chiral violation. We point out that observations of halo-galaxy angular momentum directions (spins), which are frozen in during the galaxy formation process, provide a fossil chiral observable. From the clustering mode of large scale structure of the Universe, we construct a spin mode in Lagrangian space and show in simulations that it is a good probe of halo-galaxy spins. In the standard model, a strong symmetric correlation between the left and right helical components of this spin mode and galaxy spins is expected. Measurements of these correlations will be sensitive to chiral breaking, providing a direct test of chiral symmetry breaking in the early Universe.

Role and effect of vein-transplanted human umbilical cord mesenchymal stem cells in the repair of diabetic foot ulcers in rats.

Diabetic foot ulcer (DFU) is one of diabetic complications, which is frequently present and tormented in diabetes mellitus. Most multipotent mesenchymal stromal cells (MSCs) are capable of immune evasion, providing an allogeneic, ready-to-use, cell product option for therapeutic applications. The beneficial effect of MSCs for the treatment of a variety of traumatic injuries, such as open wounds, has been extensively explored. In this study, a rat DFU model was used to simulate the pathophysiology of clinical patients and to investigate the localization of human umbilical cord mesenchymal stem cells (hUC-MSCs) after intravenous transplantation and its role in DFU healing, so as to evaluate the potential of hUC-MSCs in the treatment of DFU. The diabetic rat model was established by streptozotocin injection, which was used to create full-thickness foot dorsal skin wounds to mimic DFU by a 6-mm skin biopsy punch and a Westcott scissor. The hUC-MSCs were transplanted through femoral vein, and the ulcer cicatrization situation and the fate of hUC-MSCs were evaluated. Our data suggest that intravenously transplantated hUC-MSCs have the ability to migrate and locate to the wound tissue and are helpful to wound healing in DFU rats, partly by regulating inflammation, trans-differentiation and providing growth factors that promote angiogenesis, cell proliferation and collagen deposition. Herein, we demonstrate that hUC-MSC transplantation is able to accelerate DFU healing in rats and transplantation of exogenous stem cells may be a potential strategy for clinical application in DFUs.