nfs-utility-suite
NFS Utility Suite is a collection of code libraries that provide convenience features for working with network filesystems.
Bertschinger, Thomas↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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1D hierarchical CdS NPs/NiO NFs heterostructures with enhanced photocatalytic activity under visible light irradiation
Not Available
Deng, Chonghai (ORCID:0000000343567755)↗
Crystallization kinetics and nanoparticle ordering in semicrystalline polymer nanocomposites
There has been considerable interest in the nucleation and crystallization of polymers in the presence of nanoparticles (NPs, or nanofillers in general, NFs). Most of the extensive work in this area has focused on anisotropic, non-Brownian NFs (e.g., clay sheets, carbon nanotubes) whose spatial dispersion state in these nanocomposites is controlled by the process by which they are formed. Hence, NF spatial dispersion is generally limited and often remains poorly characterized. Thermodynamic handles that can be used to control NF dispersion state in the polymer melt include (a) favorable interactions between the polymer chains and the bare NP surfaces, or (b) the density and length of the chains, with the same chemistry as the matrix, grafted to the NP surface. These relatively large NFs merely act as stationary objects that affect the kinetics of nucleation by providing heterogeneous sites, and the crystallization rate by confining the polymer in the melt state. The dispersion state of the NFs can dramatically affect the nucleation and crystallization of the matrix, but in most cases reported, the NFs increase nucleation efficiency relative to the neat polymer. At higher NF loadings, the effect of polymer confinement by the NFs dominates, leading to a decrease in crystal growth rates. This review describes the most important lessons learned from these commonly studied systems and then extends to polymer composite systems containing small, mobile spherical NPs (typically smaller than 100 nm in size). The role of NP mobility, which provides for dynamic confinement of the polymer melt, on the kinetics of polymer crystallization (nucleation, growth, and overall crystallization) and how this behavior is mostly consistent with the case of immobile NF is a second important focus of this review. In addition to the role of NFs on crystallization kinetics, recently reported nanoparticle ordering phenomena such as the effect of matrix crystallization on the organization of small spherical NPs within the amorphous regions of the semicrystalline morphology are discussed. In conclusion, such phenomena are clearly not observed for large NFs and hence provide a point of departure from past works in this area.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Influence of amplitude-related perfusion parameters in the parotid glands by non-fat-saturated dynamic contrast-enhanced magnetic resonance imaging
Purpose: To verify whether quantification of parotid perfusion is affected by fat signals on non-fat-saturated (NFS) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and whether the influence of fat is reduced with fat saturation (FS). Methods: This study consisted of three parts. First, a retrospective study analyzed DCE-MRI data previously acquired on different patients using NFS (n = 18) or FS (n = 18) scans. Second, a phantom study simulated the signal enhancements in the presence of gadolinium contrast agent at six concentrations and three fat contents. Finally, a prospective study recruited nine healthy volunteers to investigate the influence of fat suppression on perfusion quantification on the same subjects. Parotid perfusion parameters were derived from NFS and FS DCE-MRI data using both pharmacokinetic model analysis and semiquantitative parametric analysis. T tests and linear regression analysis were used for statistical analysis with correction for multiple comparisons. Results: NFS scans showed lower amplitude-related parameters, including parameter A, peak enhancement (PE), and slope than FS scans in the patients (all with P < 0.0167). The relative signal enhancement in the phantoms was proportional to the dose of contrast agent and was lower in NFS scans than in FS scans. The volunteer study showed lower parameter A (6.75 ± 2.38 a.u.), PE (42.12% ± 14.87%), and slope (1.43% ± 0.54% s{sup −1}) in NFS scans as compared to 17.63 ± 8.56 a.u., 104.22% ± 25.15%, and 9.68% ± 1.67% s{sup −1}, respectively, in FS scans (all with P < 0.005). These amplitude-related parameters were negatively associated with the fat content in NFS scans only (all with P < 0.05). Conclusions: On NFS DCE-MRI, quantification of parotid perfusion is adversely affected by the presence of fat signals for all amplitude-related parameters. The influence could be reduced on FS scans.
60 APPLIED LIFE SCIENCES↗
Comparison of Results for Quarter 1 Surface Water Split Samples Collected at the Nuclear Fuel Services Site, Erwin, Tennessee
Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on August 22, 2012. Representatives from the U.S. Nuclear Regulatory Commission and Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses. The comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER ≤ 3 indicates that, at a 99% confidence interval, split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty. The NFS split sample report does not specify the confidence level of reported uncertainties. Therefore, standard two sigma reporting is assumed and uncertainty values were divided by 1.96. A comparison of split sample results, using the DER equation, indicates one set with a DER greater than 3. A DER of 3.1 is calculated for gross alpha results from ORAU sample 5198W0003 and NFS sample MCU-310212003. The ORAU result is 0.98 ± 0.30 pCi/L (value ± 2 sigma) compared to the NFS result of -0.08 ± 0.60 pCi/L. Relatively high DER values are not unexpected for low (e.g., background) analyte concentrations analyzed by separate laboratories, as is the case here. It is noted, however, NFS uncertainties are at least twice the ORAU uncertainties, which contributes to the elevated DER value. Differences in ORAU and NFS minimum detectable activities are even more pronounced. comparison of ORAU and NFS split samples produces reasonably consistent results for low (e.g., background) concentrations.
54 ENVIRONMENTAL SCIENCES↗
Characterization of human lung cancer-associated fibroblasts in three-dimensional in vitro co-culture model
Highlights: Black-Right-Pointing-Pointer We established three patient-paired sets of CAFs and NFs. Black-Right-Pointing-Pointer CAFs and NFs were analyzed using three-dimensional co-culture experiments. Black-Right-Pointing-Pointer CAFs clearly enhanced collagen gel contraction. Black-Right-Pointing-Pointer CAFs showed higher {alpha}-SMA expression than NFs. Black-Right-Pointing-Pointer CAFs were implicated in invasion and differentiation of lung cancer cells. -- Abstract: Lung cancer is the most common cause of cancer-related death worldwide. Stromal cancer-associated fibroblasts (CAFs) play crucial roles in carcinogenesis, proliferation, invasion, and metastasis of non-small cell lung carcinoma, and targeting of CAFs could be a novel strategy for cancer treatment. However, the characteristics of human CAFs still remain to be better defined. In this study, we established patient-matched CAFs and normal fibroblasts (NFs), from tumoral and non-tumoral portions of resected lung tissue from lung cancer patients. CAFs showed higher {alpha}-smooth muscle actin ({alpha}-SMA) expression than NFs, and CAFs clearly enhanced collagen gel contraction. Furthermore, we employed three-dimensional co-culture assay with A549 lung cancer cells, where CAFs were more potent in inducing collagen gel contraction. Hematoxylin and eosin staining of co-cultured collagen gel revealed that CAFs had the potential to increase invasion of A549 cells compared to NFs. These observations provide evidence that lung CAFs have the tumor-promoting capacity distinct from NFs.
60 APPLIED LIFE SCIENCES↗
Structural effects of field emission from GaN nanofilms on SiC substrates
GaN nanofilms (NFs) with different structures are grown on SiC substrates by pulsed laser deposition under different conditions. The synthesized GaN NFs are studied by X-ray diffraction, field-emission (FE) scanning electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. The GaN NFs are composed of diversified GaN nanoparticles with a diameter of 9–38 nm, thickness of 10–50 nm, and roughness of 0.22–13.03 nm. FE from the GaN NFs is structure dependent, which is explained by stress changing the band gap of the NFs. By structure modulation, the turn-on field of GaN NFs can be as low as 0.66 V/μm at a current density of 1 μA/cm{sup 2}, with a current density of up to 1.1 mA/cm{sup 2} at a field of 4.18 V/μm. Fowler-Nordheim curves of some samples contain multiple straight lines, which originate from the structural change and diversification of GaN nanoparticles under an applied field. Overall, our results suggest that GaN NFs with excellent FE properties can be prepared on SiC substrates, which provides a new route to fabricate high-efficiency FE nanodevices.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Electrochemical and Magnetic Properties of Electrospun SrTi{sub 1−x}Fe{sub x}O{sub 3} (x = 0, 0.05 and 0.10) Nanofibers for Anodes of Li-Ion Batteries
SrTi{sub 1−x}Fe{sub x}O{sub 3} (x = 0, 0.05 and 0.1) nanofibers (NFs) were fabricated by electrospinning technique. As prepared products were calcined at 800 {sup ∘} C in argon atmosphere for 3 h to obtain a perovskite phase. The crystal structure and morphology of samples were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Electrochemical and magnetic properties of calcined NFs were studied using a potentiostat/galvanostat electrochemical cell system and vibrating sample magnetometer (VSM), respectively. XRD results showed the cubic perovskite structure of calcined samples with the diameter estimated by TEM in the range of 137.4–141.3 nm SEM micrographs revealed the linkage of crystalline grains in NFs of porous and rough surfaces. Electrochemical properties performed on coin-cell-type Li-ion batteries (LIBs) with calcined SrTi{sub 1−x}Fe{sub x}O{sub 3} (x = 0.05 and 0.10) NF-based anodes showed a significant increase of the specific capacity from 305 to 431 mAh/g for the first cycle with the reversible values of 100 and 130 mAh/g, respectively. VSM measurements at room temperature (RT) indicated that calcined SrTiO{sub 3} NFs exhibited paramagnetic (PM) behavior, while calcined SrTi{sub 1−x}Fe{sub x}O{sub 3} NFs displayed ferromagnetic (FM) behavior at RT with the increase of unsaturated magnetization at 10 kOe from 0.46 to 0.82 emu/g for samples with x = 0.05 and 0.10, respectively. The observed FM behavior in calcined SrTi{sub 1−x}Fe{sub x}O{sub 3} (x = 0.05 and 0.1) NFs was suggested to originate from the face center exchange (FCE) mechanism owing to Fe{sup 3+} –Vo–Fe{sup 3+} couplings.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Dual-Readout Immunochromatographic Assay by Utilizing MnO 2 Nanoflowers as the Unique Colorimetric/Chemiluminescent Probe
Manganese dioxide nanoflowers (MnO2 NFs) were synthesized and utilized as a dual readout probe to develop a novel immunochromatographic test strip (ITS) for detecting pesticide residues using chlorpyrifos as the model analyte. MnO2 NFs-labeled antibody for chlorpyrifos was employed as the signal tracer for conducting the ITS. After 10-min competitive immunoreaction, the tracer antibody was captured by the immobilized immunogen on test line in the test strip, resulting in the accumulation of MnO2 NFs. The accumulation of MnO2 NFs led to the appearance of brown color on the test line, which could be easily observed by the naked eye as a qualitative readout. Moreover, MnO2 NFs showed a remarkably enhancing effect on the luminol-H2O2 chemiluminescent (CL) system. Unlike peroxidase-like nanomaterials, the enhancing mechanism of MnO2 NFs was based on its oxidant activity to decompose H2O2 for forming reactive oxygen species. After initiating the CL system in the test zone, strong CL signal was collected as a quantitative readout to sensitively detect chlorpyrifos. Under optimal conditions, the linear range of chlorpyrifos was 0.1–50 ng/mL with a low detection limit of 0.033 ng/mL (S/N = 3). The reliability of the dual-readout ITS was successfully demonstrated by the application on traditional Chinese medicine and environmental water samples. Due to the simultaneous rapid-qualitative and sensitive-quantitative detection, the dual-readout protocol provides a promising strategy for rapid screening and field assay on various areas such as environmental monitoring, food safety and point-of-care testing.
Ouyang, Hui↗
Controlled growth of vertically aligned MoO{sub 3} nanoflakes by plasma assisted paste sublimation process
In this work, we have successfully developed plasma assisted paste sublimation route to deposit vertically aligned MoO{sub 3} nanoflakes (NFs) on nickel coated glass substrate in oxygen plasma ambience with the assistant of Ni thin layer as a catalyst. In our case, sublimation source (Mo strip surface) is resistively heated by flowing current across it. The structural, morphological, and optical properties of NFs have been investigated systematically using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), High resolution transmission electron microscopy (HRTEM), micro-Raman spectroscopy, and Photoluminescence (PL) spectroscopy. Studies reveal that the presence of oxygen plasma and the nickel thin layer are very essential for the growth of vertically aligned NFs. The observed results divulge that α-MoO{sub 3} NFs are deposited uniformly on large scale with very high aspect (height/thickness) ratio more than 30 and well aligned along [0 k 0] crystallographic direction where k is even (2, 4, 6). Raman spectrum shows a significant size effect on the vibrational property of MoO{sub 3} nanoflakes. The PL spectrum of MoO{sub 3} NFs was recorded at room temperature and four prominent peaks at 365 nm, 395 nm, 452 nm, and 465 nm corresponding to UV-visible region were observed. In this paper, a three step growth strategy for the formation of MoO{sub 3} NFs has been proposed in detail.
77 NANOSCIENCE AND NANOTECHNOLOGY↗
Space charge inhibition effect of nano-Fe{sub 3}O{sub 4} on improvement of impulse breakdown voltage of transformer oil based on improved Kerr optic measurements
Transformer oil-based nanofluids (NFs) with 0.03 g/L Fe{sub 3}O{sub 4} nanoparticle content exhibit 11.2% higher positive impulse breakdown voltage levels than pure transformer oils. To study the effects of the Fe{sub 3}O{sub 4} nanoparticles on the space charge in transformer oil and to explain why the nano-modified transformer oil exhibits improved impulse breakdown voltage characteristics, the traditional Kerr electro-optic field mapping technique is improved by increasing the length of the parallel-plate electrodes and by using a photodetector array as a high light sensitivity device. The space charge distributions of pure transformer oil and of NFs containing Fe{sub 3}O{sub 4} nanoparticles can be measured using the improved Kerr electro-optic field mapping technique. Test results indicate a significant reduction in space charge density in the transformer oil-based NFs with the Fe{sub 3}O{sub 4} nanoparticles. The fast electrons are captured by the nanoparticles and are converted into slow-charged particles in the NFs, which then reduce the space charge density and result in a more uniform electric field distribution. Streamer propagation in the NFs is also obstructed, and the breakdown strengths of the NFs under impulse voltage conditions are also improved.
36 MATERIALS SCIENCE↗
The iron oxidation state of Ryugu samples
The Hayabusa2 mission sampled Ryugu, an asteroid that did not suffer extensive thermal metamorphism, and returned rocks to the Earth with no significant air exposure. It therefore offers a unique opportunity to study the redox state of carbonaceous Cb-type asteroids and evaluate the overall redox state of the most primitive rocks of the solar system. An analytical framework was developed to investigate the iron mineralogy and valence state in extraterrestrial material at the micron scale by combining x-ray diffraction, conventional Mössbauer (MS), and nuclear forward scattering (NFS) spectroscopies. An array of standard minerals was analyzed and cross-calibrated between MS and NFS. Then, MS and NFS spectra on three Ryugu grains were collected at the bulk and the micron scales. In Ryugu samples, iron is essentially accommodated in magnetite, clay minerals (serpentine–smectite), and sulfides. Only a single set of Mössbauer parameters was necessary to account for the entire variability observed in MS and NFS spectra, at all spatial scales investigated. These parameters therefore make up a fully consistent iron mineralogical model for the Ryugu samples. As far as MS and NFS spectroscopies are concerned, Ryugu grains are overall similar to each other and share most of their mineralogical features with CI-type chondrites. In detail however, no ferrihydrite is found in Ryugu particles even at the very sensitive scale of Mössbauer spectroscopy. The typical Fe 3+ /Fe tot of clay minerals is much lower than typical redox ratios measured in CI chondrites (Fe 3+ /Fe tot = 85%–90%). Furthermore, magnetite from Ryugu is stoichiometric with no significant maghemite component, whereas up to 12% of maghemite was previously identified in the Orgueil's so-called magnetite. These differences suggest that most CI meteorites suffered terrestrial alteration and that the preterrestrial composition of these carbon-rich samples was less oxidized than previously measured. However, it is not clear yet whether or not the parent bodies of CI chondrites were as reduced as Ryugu. Finally, the high spatial resolution of NFS allows to disentangle the redox state and the crystal chemistry of iron accommodated in serpentine and smectite. The most likely polytype of serpentine is lizardite, containing <35% of Fe 3+ , a fraction of which being tetrahedrally coordinated. Smectite is more oxidized (Fe 3+ /Fe tot > 65%) and mainly contains octahedral ferric iron. In conclusion, this finding implies that these clays formed from highly alkaline fluids and the spatial variability highlighted here may suggest a temporal evolution or a spatial variability of the nature of this fluid.
58 GEOSCIENCES↗
COMPARISON OF RESULTS FOR QUARTER 4 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUELS SERVICES SITE, ERWIN, TN
Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on June 12, 2013. Representatives from the U.S. Nuclear Regulatory Commission (NRC) and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and Table 1 presents the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER ≤ 3 indicates at a 99% confidence interval that split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty (ANSI N42.22). The NFS split sample report specifies 95% confidence level of reported uncertainties (NFS 2013). Therefore, standard two sigma reporting values were divided by 1.96. In conclusion, most DER values were less than 3 and results are consistent with low (e.g., background) concentrations. The gross beta result for sample 5198W0014 was the exception. The ORAU gross beta result of 6.30 ± 0.65 pCi/L from location NRD is well above NFS's non-detected result of 1.56 ± 0.59 pCi/L. NFS's data package includes no detected result for any radionuclide at location NRD. At NRC's request, ORAU performed gamma spectroscopic analysis of sample 5198W0014 to identify analytes contributing to the relatively elevated gross beta results. This analysis identified detected amounts of naturally-occurring constituents, most notably Ac-228 from the thorium decay series, and does not suggest the presence of site-related contamination.
54 ENVIRONMENTAL SCIENCES↗
COMPARISON OF RESULTS FOR QUARTER 3 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUEL SERVICES SITE, ERWIN, TENNESSEE
Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on March 20, 2013. Representatives from the U.S. Nuclear Regulatory Commission and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and Table 1 presents the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER {<=} 3 indicates that at a 99% confidence interval, split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty (ANSI N42.22). The NFS split sample report does not specify the confidence level of reported uncertainties (NFS 2013). Therefore, standard two sigma reporting is assumed and uncertainty values were divided by 1.96. In conclusion, most DER values were less than 3 and results are consistent with low (e.g., background) concentrations. The gross beta result for sample 5198W0012 was the exception. The ORAU result of 9.23 ± 0.73 pCi/L from location MCD is well above NFS's result of -0.567 ± 0.63 pCi/L (non-detected). NFS's data package included a detected result for U-233/234, but no other uranium or plutonium detection, and nothing that would suggest the presence of beta-emitting radionuclides. The ORAU laboratory reanalyzed sample 5198W0012 using the remaining portion of the sample volume and a result of 11.3 ± 1.1 pCi/L was determined. As directed, the laboratory also counted the filtrate using gamma spectrometry analysis and identified only naturally occurring or ubiquitous man-made constituents, including beta emitters that are presumably responsible for the elevated gross beta values.
54 ENVIRONMENTAL SCIENCES↗
The Neutrons for Science Facility at SPIRAL-2
The ''Neutrons for Science''(NFS) facility will be a component of SPIRAL-2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for cross-section measurements and material studies. Continuous and quasi-monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the {sup 7}Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Sensitive and Selective NH3 Monitoring at Room Temperature Using ZnO Ceramic Nanofibers Decorated with Poly(styrene sulfonate)
Ammonia (NH3) gas is a prominent air pollutant that is frequently found in industrial and livestock production environments. Due to the importance in controlling pollution and protecting public health, the development of new platforms for sensing NH3 at room temperature has attracted great attention. In this study, a sensitive NH3 gas device with enhanced selectivity is developed based on zinc oxide nanofibers (ZnO NFs) decorated with poly(styrene sulfonate) (PSS) and operated at room temperature. ZnO NFs were prepared by electrospinning followed by calcination at 500 °C for 3 h. The electrospun ZnO NFs are characterized to evaluate the properties of the as-prepared sensing materials. The loading of PSS to prepare ZnO NFs/PSS composite is also optimized based on the best sensing performance. Under the optimal composition, ZnO NFs/PSS displays rapid, reversible, and sensitive response upon NH3 exposure at room temperature. The device shows a dynamic linear range up to 100 ppm and a limit of detection of 3.22 ppm and enhanced selectivity toward NH3 in synthetic air, against NO2 and CO, compared to pure ZnO NFs. Additionally, a sensing mechanism is proposed to illustrate the sensing performance using ZnO NFs/PSS composite. Therefore, this study provides a simple methodology to design a sensitive platform for NH3 monitoring at room temperature.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Expansion of CD26 positive fibroblast population promotes keloid progression
Background: Keloid is a skin fibrosis disease that characterised by invasive growth of fibroblasts and aberrant deposition of extracellular matrix. Studies indicated that keloid fibroblasts (KFs) is a class of ‘activated’ fibroblasts, which show accelerated proliferation and excessive extracellular matrix formation as compared with normal fibroblasts (NFs). However, the mechanism underlying keloid fibroblasts dysfunction is still unknown. Objective: To verify CD26 expression difference between KFs and NFs, and investigate the function of CD26 positive fibroblasts in keloid progression. Methods: KFs and NFs were isolated from Keloid tissues and normal skin tissues respectively. Flow cytometry was performed to isolate CD26+/CD26- fibroblasts from KFs and NFs. Proliferation of different fibroblasts were analyzed by CCK8 assay and Ki 67 straining. Profibrotic phenotype difference was detected by qRT-PCR, western blot, ELISA and immunofluorescence. Scratching experiment and transwell assay were used to assess invasion ability of CD26+/CD26- fibroblasts. Diprotin A was used as a CD26 inhibitor to further investigated the function of CD26 fibroblasts in keloid disease. Result: CD26 expression was increased in KFs, and the proportion of CD26+ fibroblasts was significantly increased in KFs. Cell viability analysis showed that CD26+ fibroblasts was more active in proliferation. Furthermore, the expression of profibrotic genes were increased in CD26+ fibroblasts, including TGF-β1, IGF-1, IL6, collagen 1, collagen 3 and fibronectin. And meanwhile, CD26+ fibroblasts showed stronger invasion ability as compared to CD26- fibroblasts. Moreover, Diprotin A significantly suppressed proliferation and extracellular matrix secretion of CD26+ fibroblasts isolated from keloid tissues. Conclusion: Our findings suggest that CD26+ fibroblasts possess proliferation advantage in compare to CD26- fibroblasts, and the advantage caused expansion of CD26 positive fibroblast population promotes keloid progression.
60 APPLIED LIFE SCIENCES↗