FM-3DFR: Facial Manipulation-Based 3-D Face Reconstruction.

3-D Morphable model (3DMM) has widely benefited 3-D face-involved challenges given its parametric facial geometry and appearance representation. However, previous 3-D face reconstruction methods suffer from limited power in facial expression representation due to the unbalanced training data distribution and insufficient ground-truth 3-D shapes. In this article, we propose a novel framework to learn personalized shapes so that the reconstructed model well fits the corresponding face images. Specifically, we augment the dataset following several principles to balance the facial shape and expression distribution. A mesh editing method is presented as the expression synthesizer to generate more face images with various expressions. Besides, we improve the pose estimation accuracy by transferring the projection parameter into the Euler angles. Finally, a weighted sampling method is proposed to improve the robustness of the training process, where we define the offset between the base face model and the ground-truth face model as the sampling probability of each vertex. The experiments on several challenging benchmarks have demonstrated that our method achieves state-of-the-art performance.

Interface engineering of Fe2P@CoMnP4 heterostructured nanoarrays for efficient and stable overall water splitting.

Electrocatalytic water splitting to generate high-quality hydrogen is an attractive renewable energy storage technology; however, it is still far from becoming a real-world application. In this study, we developed an effective and stable nickel foam-supported Fe2P@CoMnP4 heterostructure electrocatalyst for overall water splitting. As expected, the as-obtained Fe2P@CoMnP4/NF electrocatalyst exhibits superb bifunctional catalytic activity and only requires extremely low overpotentials of 53 and 249 mV to achieve a current density of 10 mA cm-2 for the hydrogen and oxygen evolution reactions, respectively. Moreover, a two-electrode electrolyzer assembled using Fe2P@CoMnP4/NF as electrodes operates at the low cell voltage of 1.54 V at 10 mA cm-2, showing excellent long-term stability for 140 h. Theoretical calculations indicate that the surface electronic structure is effectively adjusted by the generated heterointerfaces between the Fe2P and CoMnP4 in a two-phase matrix, resulting in a Gibbs free energy of hydrogen adsorption close to zero and high intrinsic activity. This innovative strategy is a valuable route for producing low-cost high-performance bifunctional electrocatalysts for water splitting.

Salt stress-induced changes in soil metabolites promote cadmium transport into wheat tissues.

Soil salinity is known to improve cadmium (Cd) mobility, especially in arid soils. However, the mechanisms involved in how salt stress-associated metabolic profiles participate in mediating Cd transport in the soil-plant system remain poorly understood. This study was designed to investigate the effects of salinity-induced changes in soil metabolites on Cd bioavailability. Sodium salts in different combinations according to molar ratio (NaCl:Na2SO4=1:1; NaCl:Na2SO4:NaHCO3=1:2:1; NaCl:Na2SO4:NaHCO3:Na2CO3=1:9:9:1; NaCl:Na2SO4:NaHCO3:Na2CO3=1:1:1:1) were applied to the Cd-contaminated soils, which increased soil Cd availability by 22.36% and the Cd content in wheat grains by 36.61%, compared to the control. Salt stress resulted in soil metabolic reprogramming, which might explain the decreased growth of wheat plants and increased Cd transport from the soil into wheat tissues. For example, down-regulation of starch and sucrose metabolism reduced the production of sugars, which adversely affected growth; up-regulation of fatty acid metabolism allowed wheat plants to maintain a normal intracellular environment under saline conditions; up-regulation of the tricarboxylic acid (TCA) cycle was triggered, causing an increase in organic acid synthesis and the accumulation of organic acids, which facilitated the migration of soil Cd into wheat tissues. In summary, salt stress can facilitate Cd transport into wheat tissues by the direct effect of salt-based ions and the combined effect of altered soil physicochemical properties and soil metabolic profiles in Cd-contaminated soils.

Cp*Ir(III) and Cp*Rh(III)-catalyzed annulation of salicylaldehydes with fluorinated vinyl tosylates.

A mild, selective and redox-neutral Cp*Ir(III)- and Cp*Rh(III)-catalyzed C-H activation/annulation of salicylaldehydes with fluorovinyl tosylates is reported. The use of monofluorovinyl tosylate favors the synthesis of C2- and C3-substitution-free chromones via C-H activation/ß-F elimination/annulation, whereas difluorovinyl tosylate leads to the construction of C2-fluoroalkoxy chromones. Mild reaction conditions and good functional-group tolerance were observed. Further functionalization of the resulting chromones via halogenation, alkynylation, alkylation and hydrocyanation was successfully realized.

A new insight into Cd reduction by flooding in paddy soil: The different dominant roles of Fe and S on Cd immobilization under fluctuant pe + pH conditions.

The unsteady comprehensive system of pe + pH strongly affects the fate of Cd in paddy soils. However, the specific pe + pH threshold determining Cd bioavailability is largely unknown especially considering the roles of Fe and S reduction. The experiment set different water managements to obtain paddy soil samples with unstable pe + pH, and chemical analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterization were applied to reveal the dynamic process and mechanism about how Fe and S controlled Cd mobilization. The results showed that low pe + pH was favorable to soil Cd immobilization. Compared with high and medium pe + pH, the exchangeable Cd content decreased by 67.57 % and 64.71 % at low pe + pH, respectively. The XPS results showed that the contents of Fe(II) and S(-II) increased to 65.1 % and 75.2 % at low pe + pH condition, which was higher than that in other treatments. In the process of flooding for reducing Cd mobility, first it was attributed to the formation of amorphous iron oxides that can provide amount of adsorption sites for Cd. After then, S2- began to play a dominant role to combine with Cd2+ to form CdS with continuous decreased pe + pH. Therefore, Fe and S played the different dominant roles on Cd immobilization in paddy soil, and soil pe + pH value could work as a threshold.

Aging factor and its prediction models of chromium ecotoxicity in soils with various properties.

Aging of pollutants determines bioavailability and toxicity thresholds of environmental pollutants in soil. However, the ecotoxicity of chromium (Cr) rarely considers the effect of aging as well as soil properties. In order to explore the aging characteristics and establish their quantitative relationship with different soil properties, this study selected 7 soils with different properties through exogenous addition of Cr and determined its toxicity on barley root elongation. From 14d to 540d, EC10 and EC50 of barley root elongation ranged from 21.40 to 312.52 (mg·kg-1) and 50.15 to 883.88 (mg·kg-1) respectively. The hormesis appeared in the dose-response curve of acid soil as relative barley root elongation reached >110 % compared with the control. Extended aging time of Cr from 14d to 540d was associated with the attenuation of the toxicity of Cr, as the aging factor increased from 1.26 to 6.09 for EC50, from 0.88 to 4.98 for EC10. The prediction model of AFEC50 and soil properties is lg (AF360d) = 0.306lg Clay+0.026lg CEC + 0.240 (R2 = 0.872, P < 0.01). The results demonstrated that with the extension of aging time, the toxicity of Cr decreased at 360d and reached a slow reaction stage, after that soil OC, Clay and CEC could well explain the aging procedure of Cr (VI). These results are beneficial for risk assessment of Cr contaminated soils and establishment of a soil environmental quality criteria for Cr.

Linking Bacterial Growth Responses to Soil Salinity with Cd Availability.

This study investigated the effects of different types of saline stress on the availability of cadmium (Cd) and bacterial growth. Changes in soil physicochemical properties and DTPA-Cd content as well as microbial responses after the addition of salts were measured. The addition of 18 g kg-1 of salts with NaCl and Na2SO4 increased the available Cd content by up to 17.80%-29.79%. Respiration rate, biomass, and relative bacterial growth decreased with increasing salt concentrations. Estimated salinity tolerance of bacterial communities based on pollution-induced community tolerance. The salinity tolerance index EC50 of the bacterial community was estimated by logistic equation and ranged from 4.32-12.63 g kg-1. Structural equation modeling showed that soil salinity stress significantly affected Cd availability and bacterial community, while bacterial growth characteristics also contributed to reducing available Cd. We conclude that saline stress can alter soil Cd availability in soils by affecting the growth characteristics of soil bacterial communities.

Ecological risk thresholds for Zn in Chinese soils.

The environmental risk threshold of a pollutant is a yardstick to measure soil environmental quality. The derivation of ecological risk thresholds of the heavy metal zinc (Zn) in soil environments based on up-to-date ecological risk assessments plays an important role in soil protection policy. According to regional soil classification, different representative soils with various degrees of acidity and alkalinity were selected, and a data set comprising ecotoxicities of Zn to 21 different test endpoints (plants, soil fauna, microorganisms, etc.) found in representative farmland soils of China was compiled based on new and published data to determine toxicological limits of Zn effects on endpoints. These limits were derived from fitted dose-response model parameters and indicated by EC10 values (the effective concentrations of Zn that inhibit 10% of endpoint bioactivity and also represents the toxicity threshold of Zn in this study) ranging from 36 mg·kg-1 to 682 mg·kg-1. The hormesis effect appeared in the dose-response curve of Zn, for example, the relative Chinese cabbage growth reached more than 120% at most. Zn concentrations added in toxicity tests were also corrected for aging and leaching effects in order to more accurately reflect field conditions. The hazardous concentrations for 5% of the species affected (HC5) were derived by the species sensitivity distribution (SSD) approach for four major types of Chinese soils: acidic (38 mg·kg-1), neutral (106 mg·kg-1), alkaline (217 mg·kg-1), and alkaline calcareous soils (155 mg·kg-1). Prediction models of ecological risk thresholds for Zn based on soil properties were generated, such as logHC5 = 0.564 + 0.218pH + 0.097OC (R2 = 0.790,p < 0.001). The predicted models based on lab test data were verified in the field, and the measured field data fell within two-fold of the prediction intervals. This work provides a scientific framework for developing soil-specific guidance on Zn toxicity thresholds.

Effect of soil leaching on the toxicity thresholds (ECx) of Zn in soils with different properties.

Currently, the scientific basis for establishing soil environmental criteria is lacking. In order to establish reasonable soil environmental criteria values suitable for soils with different properties, this study selected soils from 16 different sites to determine the toxicity threshold of Zn based on toxicity tests of barley root elongation. In addition, leaching treatments were set up in seven soils with different properties to eliminate the influence of the accompanying anions (Cl-) on the determination of the Zn toxicity threshold. The results indicated that the toxicity thresholds of different soils vary greatly. The EC10 and EC50 ranges of barley root elongation in 16 kinds of non-leached soils were 18.5 mgkg-1 to 1618.7 mgkg-1 and 277.9 mgkg-1 to 3179.8 mgkg-1, respectively. The hormesis effect appeared in the dose response of Zn, and relative barley root elongation reached more than 150%. Leaching significantly reduced the Zn toxicity in acidic soils. The variation ranges of the leaching factor (LF) in the seven soils were LF10 = 1.1-9.3, LF50 = 1.0-3.2. The LF prediction model indicated that pH explained 81.4% of the LF variation (p < 0.01). The soil pH, cation exchange capacity (CEC), and conductivity (EC) explained 97.8% of the EC50 variation in the leached soil (p < 0.01). The results provide reference values for Zn environmental criteria.

Manganese facilitates cadmium stabilization through physicochemical dynamics and amino acid accumulation in rice rhizosphere under flood-associated low pe+pH.

Periodic flooding in paddy soils impacts redox behavior and induces variations in pe+pH levels. Manganese (Mn) is capable of reducing cadmium (Cd) uptake by rice. However, the processes involved in how Mn alters Cd mobilization under different pe+pH environments remain poorly understood. To investigate the mechanisms of Mn-mediated soil Cd-stabilization and subsequent inhibition of Cd uptake from flooded soils, we examined Cd immobilization in soil pot incubations, transcriptional changes in Cd-transport genes, and metabolomic analyses of roots and rhizosphere soils with or without Mn application. We found a decrease in extractable Cd concentration largely depended on irrigation-associated low pe+pH, exogenous Mn enhancement of Fe-Mn (oxyhydro)oxide-mediated Cd transformation, and Cd deposition in rice Fe/Mn plaques. Mn application led to striking effects on the expression of Cd-related genes eg. IRT, HMA, and NRAMP in rice root tissue. Exposure to Mn under variable pe+pH levels resulted in metabolic reprogramming of soil and rice roots. Mn induced amino acid synthesis in rice roots, leading to rhizosphere accumulation of free L-lysine, glycine, and glutamine, which can reportedly bind metal ions, forming complexes with Cd. Thus, secreted amino acids, low pe+pH, and free Mn can together comprise a multi-faceted approach to managing Cd toxicity in rice.

Fe(III) reduction due to low pe+pH contributes to reducing Cd transfer within a soil-rice system.

Effect of Fe redox state caused by low soil pe+pH levels on Cd uptake by rice is unclear. Rice grown in pots of Cd-contaminated paddy soil were subjected to different irrigation regimes: flooding, intermittent flooding (Int-FL), and sustained soil moisture at 70% water holding capacity (WHC). Results showed low pe+pH (5.52 and 7.09) in flooding treatment significantly increased relative abundances of Fe-reducing bacteria (FeRB) (6.29% and 4.51%), especially members within the Clostridium, Geobacter and Desulfuromonadia genera. Stimulation of FeRB activity induced Fe(III) reduction and increased Fe2+ content in flooded soils, which promoted Cd sequestration in low-crystalline fraction of IP (IP-Feh-Cd) and Cd bonded to amorphous Fe-oxides (amFeox-Cd). The 24.9-62.4% higher amFeox-Cd content was the important factor for 20.4-44.2% lower CaCl2-extractable Cd content in flooding treatment than those in other treatments. Soil submergence reduced Cd uptake by rice at tillering and booting stages, the critical periods of Cd transport in the soil-rice system, which was attributed to the increases in dissolved Fe2+ and IP-Feh-Cd contents and decrease in CaCl2-Cd content. Therefore, maintaining flooding during the tillering and booting stages may be an effective strategy to reduce Cd uptake by rice cultivated in Cd-contaminated soil.

Algal Lysis by Sagittula stellata for the Production of Intracellular Valuables.

The purpose of this study was to examine the efficacy of the algicidal bacterium Sagittula stellata on the cell lysis of Nannochloropsis oceanica, a microalga found in the marine environment, in order to extract intracellular valuables. Algicidal bacteria are capable of lysing algal cell walls while keeping lipids and proteins intact yet separated. We obtained these microbes from locations with consistent algae blooms and found that the bacterium Sagittula stellata displayed significant algicidal properties toward Nannochloropsis oceanica, achieving an algicidal rate of 80.1%. We detected a decrease of 66.2% in in vivo fluorescence intensity in algae cultures, obtained a recoverable crude lipid content of 23.3% and a polyunsaturated fatty acid (PUFA) ratio of 29.0% of bacteria-treated algae, and observed the lysis of the cell membrane and the structure of the nucleus of algae. We also identified the inhibited transcription of the ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (rbcS) gene and proliferating cell nuclear antigen (PCNA)-related genes and the upregulated heat shock protein (hsp) gene in algal cells during bacterial exposure. Our results indicate that Sagittula stellata effectively lysed microalgae cells, allowing the recovery of intracellular valuables. The algicidal method of Sagittula stellata on Nannochloropsis oceanica cells was confirmed to be a direct attack (or predation), followed by an indirect attack through the secretion of extracellular algicidal compounds. This study provides an important framework for the broad application of algicidal microorganisms in algal cell disruption and the production of intracellular valuables.

Application study of three-dimensional printed navigation template between traditional and novel cortical bone trajectory on osteoporosis lumbar spine.

To investigate the safety, accuracy and indications of traditional and novel cortical bone screws placement for osteoporosis lumbar spine, 4 lumbar vertebra specimens (2 males and 2 females) were used for this study. After the computed tomography scanning data of the above anatomical specimens were three-dimensional (3D) reconstructed, one side of each anatomical specimen was randomly chosen to place traditional cortical bone screws, and the other side received novel technical placement. The safety screw trajectory was designed, and a 3D navigation template complementary to the surface anatomical structure of lumbar isthmus lateral margin-vertebral plate-spinous process part was established. The designed supporting navigation template was substantialized, and the navigation template replicated different cortical bone screw trajectory at different sides of the same one lumbar vertebra. Forty cortical bone screws were firstly placed in 3D printed vertebra and then 40 were placed in real anatomical specimens. In 3D printed specimens, the success rates of screw placement with navigation template using traditional and novel techniques were both 100%. While in anatomical specimens, the success rate of screw placement using traditional and novel navigation template was 97.5% (one out of 40 went wrong). Therefore, it is safe, accurate and reliable to place traditional and novel cortical bone screws on osteoporosis lumbar spine using 3D printed navigation template. Traditional and novel screw placement methods should be flexibly applied or combined according to specific sequence and form of vertebra.

Electrons-Donating Derived Dual-Resistant Crust of VO2 Nano-Particles via Ascorbic Acid Treatment for Highly Stable Smart Windows Applications.

Traditional vanadium dioxide (VO2) material faced severe challenges of low stability in acid, humid, and oxygenic environments, which hinder its real applications. Here, we report a facile improving process which can enhanced the stability of VO2 nanocrystals in the environments above. Ascorbic acid (AA), as an important antioxidant for organism in medicine and biology, was ingeniously used for enhancing the antioxidation abilities of inorganic material. At the same time, the AA could generate the hydrogen doping occurred on the surface of VO2 nanocrystals, which enhanced their Antiacid abilities simultaneously. The AA treated VO2 nanocrystals retain stable in H2SO4 and H2O2 solution and exhibit high durability in hyperthermal (60 °C) and humid (90%) environment. Characterizations and first-principles theoretical calculations confirmed that the coordination of ascorbic acid molecules on VO2 nanocrystals induced charge-carrier density reorganization and protons transferring electrostatically. Then the formed HxVO2 provides an enhancing formation energy for oxygen vacancy and protects the particles from corrosion. This work is beneficial to the VO2 nanoparticles coated and decorated processes and exhibit good potential for practical application of VO2-based smart windows.

Room-Temperature Synthesis of Inorganic-Organic Hybrid Coated VO2 Nanoparticles for Enhanced Durability and Flexible Temperature-Responsive Near-Infrared Modulator Application.

Vanadium dioxide is one kind of desirable infrared modulator for sensors because of its remarkable temperature-responsive infrared modulation ability via autogeneic metal-insulator transition. However, the detriments of poor chemical stability and narrow scope of extensive-researched application (e.g., smart windows) restrict its mass production. Here, we propose a VO2@MgF2@PDA inorganic-organic hybrid coated architecture for greatly enhancing the optical durability more than 13 times in contrast to pristine VO2 and the transmittance difference between room and high temperature changed within 20% (decreasing from 25 to 20.1%) at λ = 1200 nm after the ageing time of 1000 h at constant temperature (60 °C) and relative humidity (90%). Furthermore, based on the as-synthesized durability-enhanced nanoparticles, we fabricated a flexible sensor for temperature-field fluorescence imaging by integrating the VO2-based near-infrared modulator with the upconversion fluorescence material. Additionally, the formation mechanism of VO2@MgF2 core-shell nanoparticles was studied in detail. The inorganic-organic combination strategy paves a new way for improving the stability of nanoparticles, and the use of VO2-based flexible temperature-fluorescence sensors is a promising technique for remote and swift temperature-field distribution imaging on complicated and campulitropal surfaces.

Tuning the morphology, luminescence and magnetic properties of hexagonal-phase NaGdF4: Yb, Er nanocrystals via altering the addition sequence of the precursors.

Hexagonal-phase NaGdF4: Yb, Er upconversion nanocrystals (UCNCs) with tunable morphology and properties were successfully prepared via a thermal decomposition method. The influences of the adding sequence of the precursors on the morphology, chemical composition, luminescence and magnetic properties were investigated by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), upconversion (UC) spectroscopy, and a vibrating sample magnetometer (VSM). It was found that the resulting nanocrystals, with different sizes ranging from 24 to 224 nm, are in the shape of spheres,  hexagonal plates and flakes; moreover, the composition percentage of Yb3+-Er3+ and Gd3+ ions was found to vary in a regular pattern with the adding sequence. Furthermore, the intensity ratios of emission colors (f g/r, f g/p), and the magnetic mass susceptibility of hexagonal-phase NaGdF4: Yb, Er nanocrystals change along with the composition of the nanocrystals. A positive correlation between the susceptibility and f g/r of NaGdF4: Yb, Er was proposed. The decomposition processes of the precursors were investigated by a thermogravimetric (TG) analyzer. The result indicated that the decomposition of the resolved lanthanide trifluoroacetate is greatly different from lanthanide trifluoroacetate powder. It is of tremendous help to recognize the decomposition process of the precursors and to understand the related reaction mechanism.

[Modulatory effect of Rac1 protein on epidermal stem cells migration during wound healing].

OBJECTIVE: To investigate modulatory role of Rac1 protein in epidermal stem cell (ESC) migration during wound healing, in order to provide a reference for enriching basic theory of wound healing and guiding clinical application. METHODS: Constitutively active mutant of Rac1 protein (Rac1Q61L) or dominant negative isoform of Rac1 protein (Rac1T17N) was transfected into ESC using a retroviral vector FUGW, and retroviral vector FUGW transfected into ESC in singles was used as blank control. The cells were divided into 3 parts according to the random number table and treated as follows. First, equal numbers of cells were inoculated into 24-well plates coated with collagen I (20 µg/mL), collagen IV (20 µg/mL) or fibronectin (10 µg/mL). Cells adhered to above matrices were quantitated using CytoTox 96 colorimetric kit. Second, 1000 cells adhered to collagen IV, after being stained with tetramethyl rhodamine isothiocyanate-phalloidin, were collected for observation of cell morphology and comparison of spreading area under confocal laser scanning microscope. Third, ESC with density of 2 × 10(5) cells per well were placed in upper compartment of Transwell chamber, DK-SFM culture medium alone or that containing stromal cell derived factor 1 (SDF-1) was added into lower compartment of Transwell chamber. Migration of ESC was observed using inverted phase contrast microscope, and the result was denoted as migration rate. Lastly, ESC with density of 7.5 × 10(5) cells per well was inoculated into 6-well plates for 12 hours, and treated with 4 µg/mL mitomycin C for 2 hours. The remaining scratch width of monolayer was respectively measured 6 hours or 12 hours after scratching to calculate the percentage of remaining scratch width. Data were processed with t test. RESULTS: Compared with that of blank control, the number of Rac1Q61L-transfected cells adhered to collagen I was significantly increased (t = 5.302,P < 0.05), while the number of Rac1T17N-transfected cells adhered to collagen I, IV, and fibronectin were all obviously decreased (with t value respectively 13.741, 15.676, 8.256, P values all below 0.05). Confocal laser scanning microscope showed that spreading area of Rac1Q61L-transfected ESC (with laminate pseudopodia on edge) and Rac1T17N-transfected ESC was respectively larger and smaller as compared with that of blank control. With SDF-1 effect, the migration rate of Rac1T17N-transfected ESC was decreased by 78.0% and Rac1Q61L-transfected ESC was increased by 43.4% as compared with that of blank control. Without SDF-1 effect, the migration rate of Rac1T17N-transfected ESC was decreased by 55.2%, while the migration rate of Rac1Q61L-transfected ESC was close to that of blank control. Six or 12 hours after scratching, the percentage of remaining scratch width in Rac1Q61L-transfected ESC was lower as compared with that in blank control [(39 ± 9)% vs. (43 ± 5)%, (6 ± 5)% vs. (18 ± 7)%, with t value respectively 1.027, 4.389, with P value respectively above and below 0.05], while that in Rac1T17N-transfected ESC [(81 ± 9)%, (71 ± 11)%, respectively] was obviously higher as compared with that in blank control (with t value respectively 11.386, 11.726, P values all below 0.05). CONCLUSIONS: Rac1 protein may control the migration of ESC by regulating its adhesion, spreading, and chemotaxis, and it plays an active role in wound healing accelerated by ESC.

[Promotion effect of stromal cell-derived factor 1 on the migration of epidermal stem cells in the healing process of frostbite-wound model ex vivo].

OBJECTIVE: To study the promotion effect of stromal cell-derived factor 1 (SDF-1) on the migration of epidermal stem cells (ESC) in the healing process of frostbite-wound model ex vivo. METHODS: A three-dimensional model of full-thickness frostbite of skin was constructed (with slot-like wound) out of skin equivalent. The expression of SDF-1 in wound stroma was observed with immunohistochemistry staining on post injury days (PID) 3 and 7. The model frostbite wounds were divided into control group (treated with PBS 50 microL per wound), SDF-1 group (treated with 100 ng/mL SDF-1, 50 microL per wound), and AMD3100 group [treated with 100 ng/mL AMD3100 (50 microL per wound) for 30 minutes, and then SDF-1 50 microL was added per wound]. The redistribution of ESC around wound was observed. RESULTS: The expression of SDF-1 in wound stroma increased gradually on PID 3 and 7. Compared with those in control and AMD3100 groups, there were more ESC and epithelial cell layers, and more integrin beta(1)-positive cells appeared at the basal layer of wound in SDF-1 group, and some of the positive cells migrated upward to epidermis. CONCLUSIONS: SDF-1 contributes to wound repair through promoting ESC to migrate toward and gather around wound edge. This may be one of the mechanisms of ESC participating in wound repair.