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ABSTRACT: In this study, the effect of calcitonin on lumbar spinal fusion was studied in a New Zealand rabbit model.
To investigate whether calcitonin can enhance lumbar spinal fusion in a New Zealand rabbit model and whether calcitonin can enhance expression genes involved in osteogenesis and angiogenesis.
Calcitonin is used to treat osteoporosis and diseases involving accelerated bone turnover. Studies have shown that calcitonin might also promote bone cell proliferation and bone formation, suggesting its possible role in promoting spinal fusion, but few data are available.
The effect of calcitonin on lumbar spinal fusion was analyzed in 32 New Zealand rabbits. Each rabbit received 2 autologous iliac bone grafts (one between L4-L5 without fixation, one between L6-L7 with fixation). Sixteen rabbits received calcitonin (calcitonin group, 1 U/kg daily from day 1 to the day of sacrifice), whereas the other 16 did not (control). At weeks 1, 2, 4, and 8, after examination for spinal fusion with radiography, 4 rabbits from each group were sacrificed. Each graft was histologically scored under light microscopy. In addition, we analyzed the messenger RNA (mRNA) levels of collagen I (Col I), bone morphometric protein 2 (BMP-2), insulinlike growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), genes known to be involved in osteogenesis and angiogenesis, in each graft.
With both fixation and without fixation, the bone grafts in rabbits receiving calcitonin showed a higher spinal fusion rate and higher histologic scores from week 2 to week 8, and had higher mRNA levels of Col I, BMP-2, IGF-1, and VEGF at all time points except BMP-2 and IGF-1 at week 1, than grafts in rabbits without receiving calcitonin.
Calcitonin can enhance lumbar spinal fusion. One mechanism might be through upregulating genes involved in osteogenesis and angiogenesis.
Spine 07/2011; 37(3):E139-46. · 2.08 Impact Factor
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ABSTRACT: Degenerative scoliosis (DS) is an important degenerative lumbar disease causing spinal dysfunction and affecting the quality of life of the elderly, and is associated not only with severe back or leg pain but also with complicated surgical outcomes. The pathogenesis of DS is still unknown. Therefore, it is very important to ascertain the etiology of degenerative scoliosis and establish related molecular markers predicting and controlling the scoliosis. For the first time, we used two-dimensional fluorescence DIGE to compare the serum proteome profiles of 12 DS patients and controls. Proteins found to be differentially expressed were identified by MALDI-TOF mass spectrometric analysis, coupled with database interrogation. Eleven spots that were differentially expressed in the sera of DS patients were found, and eight gene products were identified among these spots. Clusterin, CLU cDNA FLJ57622, ALB cDNA FLJ50830, Hypothetical short protein, HLA-A MHC class 1 antigen. (Fragment), ALB 23 kDa protein, Isoform 1 of G protein-regulated inducer of neurite outgrowth 1 (GPRIN I)and Ficolin-3 were down-regulated in the sera of DS patients. The decreased levels of Clusterin and Ficolin-3 were confirmed by Western blot. The information obtained with this proteomic analysis will be very useful in understanding the pathophysiology of DS as well as in finding candidates as drug targets of DS. These results may provide a novel approach for the pathogenesis study of DS.
Journal of Orthopaedic Research 06/2011; 29(12):1896-903. · 2.81 Impact Factor
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ABSTRACT: Th17 play a central role in autoimmune inflammatory responses. Th1 are also necessary for autoimmune disease development. The interplay of Th1 signals and how they coordinate with Th17 during inflammatory disease pathogenesis are incompletely understood. In this study, by adding Stat4 deficiency to Stat6/T-bet double knockout, we further dissected the role of Stat4 in Th1 development and colitis induction. We showed that in the absence of the strong Th2 mediator Stat6, neither Stat4 nor T-bet is required for IFN-γ production and Th1 development. However, addition of Stat4 deficiency abolished colitis induced by Stat6/T-bet double-knockout cells, despite Th1 and Th17 responses. The failure of colitis induction by Stat4/Stat6/T-bet triple-knockout cells is largely due to elevated Foxp3(+) regulatory T cell (Treg) development. These results highlight the critical role of Stat4 Th1 signals in autoimmune responses in suppressing Foxp3(+) Treg responses and altering the balance between Th17 and Tregs to favor autoimmune disease.
The Journal of Immunology 06/2011; 186(11):6597-606. · 5.79 Impact Factor
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ABSTRACT: To investigate apoptosis of osteoarthritic (OA) chondrocytes stimulated with different inhibitors targeting tumor necrosis factor-alpha (TNFα) pathway, we isolated first passage chondrocytes from OA patients and then treated them with the inhibitors in combination with TNFα, and then collected the stimulated chondrocytes for Western blotting. Chondrocytes from OA patients expressed cleaved caspase-3 and PARP, suggesting apoptotic background. We here, validated that 10 ng/ml of TNFα couldn't induce more chondrocytes apoptosis. PI3K inhibitor LY294002 or NF-κB inhibitor CAPE, but not mTOR inhibitor rapamycin and MEK1/2 inhibitor U0126 in combination with TNFα could facilitate apoptosis. CAPE-induced more apoptosis could be explained by c-FLIP downregulation more than cIAP1 upregulation. And, we showed the first time that PI3K-NF-κB pathway, but not mTOR pathway could prevent chondrocytes apoptosis induced by a pro-apoptotic factor TNFα and call for attention while trying to inhibit NF-κB as a therapeutic target.
Rheumatology International 04/2011; 32(7):2017-22. · 1.88 Impact Factor
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ABSTRACT: BMI-1 is a member of the polycomb group of genes (PcGs), and it has been implicated in the development and progression of several malignancies, but its role in osteosarcoma remains to be elucidated.
In the present study, we found that BMI-1 was overexpressed in different types of osteosarcomas. Downregulation of BMI-1 by lentivirus mediated RNA interference (RNAi) significantly impaired cell viability and colony formation in vitro and tumorigenesis in vivo of osteosarcoma cells. BMI-1 knockdown sensitized cells to cisplatin-induced apoptosis through inhibition of PI3K/AKT pathway. Moreover, BMI-1-depletion-induced phenotype could be rescued by forced expression of BMI-1 wobble mutant which is resistant to inhibition by the small interfering RNA (siRNA).
These findings suggest a crucial role for BMI-1 in osteosarcoma pathogenesis.
PLoS ONE 01/2011; 6(2):e14648. · 4.09 Impact Factor
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ABSTRACT: Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine. The cause and pathogenesis of scoliosis and the accompanying generalized osteopenia remain unclear despite decades of extensive research. In this study, we utilized two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry (MS) to analyze the differential proteome of bone marrow mesenchymal stem cells (BM-MSCs) from AIS patients. In total, 41 significantly altered protein spots were detected, of which 34 spots were identified by MALDI-TOF/TOF analysis and found to represent 25 distinct gene products. Among these proteins, five related to bone growth and development, including pyruvate kinase M2, annexin A2, heat shock 27 kDa protein, γ-actin, and β-actin, were found to be dysregulated and therefore selected for further validation by Western blot analysis. At the protein level, our results supported the previous hypothesis that decreased osteogenic differentiation ability of MSCs is one of the mechanisms leading to osteopenia in AIS. In summary, we analyzed the differential BM-MSCs proteome of AIS patients for the first time, which may help to elucidate the underlying molecular mechanisms of bone loss in AIS and also increase understanding of the etiology and pathogenesis of AIS.
PLoS ONE 01/2011; 6(4):e18834. · 4.09 Impact Factor
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ABSTRACT: The aim of this study is to investigate visfatin levels in both synovial fluid (SF) and plasma of patients with primary knee osteoarthritis (OA) and its relationship with biomarkers of cartilage degradation in SF. Thirty OA patients, 12 SF control, and 12 plasma control subjects were enrolled in this study. Visfatin levels in both SF and plasma were measured using enzyme-linked immunosorbent assay (ELISA). Degradation biomarkers of collagen II and aggrecan in SF were also measured. The radiographic grading of OA in the knee was performed by the Kellgren-Lawrence (KL) criteria. Compared to controls, OA patients had higher SF visfatin concentration (8.95 ± 2.5 vs. 4.48 ± 2.49 ng/ml, P < 0.001). SF visfatin levels in KL grade 4 were significantly elevated compared with those of KL grade 3 (10.57 ± 2.49 vs. 7.54 ± 1.5 ng/ml, P = 0.001). SF visfatin positively correlated with degradation biomarker of collagen II, CTX-II (r = 0.497, P = 0.005), and degradation biomarker of aggrecan, AGG1 (r = 0.451, P = 0.012) and AGG2 (r = 0.434, P = 0.017). These findings suggest that SF visfatin might involved in cartilage matrix degradation.
Rheumatology International 01/2011; 32(4):985-90. · 1.88 Impact Factor
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ABSTRACT: Alternations in cartilage chondrocyte phenotype characteristic by the decreased type II collagen and aggrecan together with increased type X collagen synthesis serve as a beacon for osteoarthritis progression. However, little is known about the underlying molecular mechanisms. The current study seeks to discover molecules that involved in osteoarthritic chondrocytes phenotype regulation. Differential proteomics was generated with two-dimensional gel electrophoresis between normal articular cartilage (NAC) and advanced osteoarthritic cartilage (AOC). Those differentially expressed proteins were identified by mass spectrometry. The down-regulation of a neuronal silencer, the REST corepressor (CoREST) in AOC, was verified by Western blot. CoREST silencing was performed in primarily cultured NAC chondrocytes with specific siRNA to reveal the possible involvement of CoREST repression in chondrocyte phenotypic genes modulation. Ninteen differentially expressed proteins were screened and identified. Among these proteins, CoREST, HHL, and zinc finger protein 155 were estimated to be possible gene modulators. CoREST protein level was verified to be down-regulated by 69.5% (p < 0.001) in AOC. In response to CoREST knock-down by 64.8% (p < 0.001) in NAC chondrocytes, the gene expression level of the chondrocyte terminal differentiation marker gene, collagen X was found to be up-regulated by 40.0% (p = 0.017), whereas the chondrocyte differentiation phenotypic genes, collagen II and aggrecan were down-regulated by 71.4% (p < 0.001) and 57.6% (p < 0.001), respectively. The results indicate that the silencing of CoREST by siRNA transfection in NAC may reflect CoREST repression in AOC, which results in phenotypic genes modulation and suggests a homeostatic role of this transcription factor in articular chondrocyte.
Journal of Orthopaedic Research 12/2010; 28(12):1569-75. · 2.81 Impact Factor
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ABSTRACT: Leptin affects a number of cell signaling pathways, at present, the mechanism(s) by which leptin affects the cartilage cells in OA patient is not well understood. The current study seeks to elucidate whether leptin induces cytoskeletal remodeling in chondrocytes and the possible involvement of the RhoA/ROCK pathway and its downstream mediators in this process. Fluorescent resonance energy transfer (FRET) and western analysis were used to determine the activations of the key proteins in the RhoA/LIMK1/Cofilin pathway. Accompanying cytoskeletal remodeling was elucidated. Upon leptin stimulation, a substantial increase of RhoA activity localized at one end of the cell was observed from 2 to 30 min post-stimulation. The results of Western blot showed leptin significantly increased LIMK1 and cofilin-2 phosphorylation in a time-dependent manner with maximal stimulation attained 60 min and 24 h post-stimulation, respectively. Chondrocytes stimulated with leptin exhibited an epithelioid morphology with increased cellular spreading. F-actin in leptin-stimulated chondrocytes also showed more intense cytoplasmic staining with occasional localization along filamentous structures. The results indicate that leptin activates the RhoA/ROCK/LIMK/cofilin pathway, which results in cytoskeletal reorganization in chondrocytes. These findings provide novel evidence supporting the possible involvement of leptin and the RhoA pathway in the pathogenesis of OA.
Journal of Orthopaedic Research 09/2010; 29(3):369-74. · 2.81 Impact Factor
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ABSTRACT: The objective of this study was to investigate adiponectin levels in both plasma and synovial fluid of female patients with knee osteoarthritis (OA) and to analyze the correlation between adiponectin and degradation markers of cartilage matrix in synovial fluid. Thirty female patients with knee OA were enrolled in this study. Levels of adiponectin and degradation markers of cartilage matrix were measured using enzyme-linked immunosorbent assay. Adiponectin level in synovial fluid was significantly lower with respect to paired plasma level (0.93 ± 0.64 vs. 7.50 ± 3.29 μg/ml, P < 0.001). Correlation analysis showed that synovial fluid adiponectin significantly correlated with degradation markers of aggrecan, AGG1 (r = 0.441, P = 0.015) and AGG2 (r = 0.445, P = 0.014), but not significantly correlated with degradation marker of collagen II, CTX-II. These findings suggest that adiponectin might involve in the regulation of the degradation of cartilage matrix in OA.
Rheumatology International 05/2010; 31(11):1433-7. · 1.88 Impact Factor
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ABSTRACT: A case-control association study was conducted to investigate the genetic etiology for congenital scoliosis (CS) in a Chinese Han population.
To identify whether TBX6 polymorphisms are associated with susceptibility to CS in a Chinese Han population.
CS is a 3-dimensional deformity of the spine, resulting from defection of normal vertebral development. Although there are many types of defects observed in CS, all result from abnormal formation and segmentation of the vertebral precursors, called somites. Developmental studies in animal models have identified many genes regulating somite formation and segmentation. T-box factor, TBX6, is a prerequisite for somite segmentation in vertebrates. In mouse TBX6 knockouts, the phenotypes are similar with that of some human birth defects, such as CS, raises the possibility that TBX6 gene may be a potential susceptibility gene for CS, so we investigated the relations between TBX6 polymorphisms and CS.
Two known single-nucleotide polymorphisms (SNPs) of TBX6 gene were genotyped among 254 Chinese Han subjects (127 CS patients and 127 controls with matched sex and age) by GenomeLab SNPstream genotyping system. The 2 markers (the only tagging SNP and a functional SNP) with minor allele frequency above 5% were analyzed by the allelic and genotypic association analysis, the genotype-phenotype (CS patients were divided into type I 31 cases [failure of formation], type II 46 cases [a failure of segmentation], and type III 50 cases [mixed defects]) association analysis, and the haplotype analysis.
The single SNP analysis showed allele frequency of rs2289292 (exon 8, the only tagging SNP) and rs3809624 (5' untranslated region) demonstrated significant difference between CS cases and controls (P = 0.017 and P = 0.033). No SNP was found to be correlated with clinical phenotype. Moreover, the 2 makers (rs2289292 and rs3809624) in TBX6 gene were found to be in strong linkage disequilibrium (D' = 1.0; gamma = 0.984; 95% confidence interval, 0.96-1.0; LOD = 57.48) in the controls. Both global haplotype analysis and individual haplotype analysis showed that the haplotype of SNP1/SNP2 showed significant association with the disease (P = 0.017), G-A haplotype was more frequently observed in controls than in cases (odds ratio, 0.71; 95% confidence interval, 0.51-0.99).
This is the first report on SNPs of TBX6 gene in CS that suggests genetic variants of TBX6 gene is associated with CS and may play an important role in mediating susceptibility to developing CS in the Chinese Han population.
Spine 03/2010; 35(9):983-8. · 2.08 Impact Factor
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ABSTRACT: Matrix metalloproteinase (MMP)-13 has pivotal roles in the pathogenesis of Osteoarthritis (OA) and it is necessary to understand the regulatory mechanisms of MMP-13 expression. MMP-13 gene expression is regulated primarily at the transcriptional level. In this study, we investigated the role of c-maf in regulating MMP-13 transcription. Using transient transfection system with an c-maf construct, and MMP-13 promoter-luciferase constructs with specific mutations in transcription factor binding sites, we found that c-maf can significantly enhance MMP-13 promoter activity via the AP-1 site, By gene suppression with RNAi technology, we could show that c-maf downregulation leads to a reduced expression of MMP13. Chromatin immunoprecipitation assays reveal that c-maf binds to the MMP-13 gene promoter to a region of the MMP-13 promoter containing the AP-1 site. Taken together, these studies demonstrate a new level of transcriptional regulation of MMP-13 expression by the c-maf.
Connective tissue research 01/2010; 51(1):48-54. · 1.55 Impact Factor
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ABSTRACT: The etiology of adolescent idiopathic scoliosis is undetermined despite years of research. A number of hypotheses have been postulated to explain its development, including growth abnormalities. The irregular expression of growth hormone and insulin-like growth factor-1 (IGF-1) may disturb hormone metabolism, result in a gross asymmetry, and promote the progress of adolescent idiopathic scoliosis. Initial association studies in complex diseases have demonstrated the power of candidate gene association. Prior to our study, 1 study in this field had a negative result. A replicable study is vital for reliability. To determine the relationship of growth hormone receptor and IGF-1 genes with adolescent idiopathic scoliosis, a population-based association study was performed. Single nucleotide polymorphisms with potential function were selected from candidate genes and a distribution analysis was performed. A conclusion was made confirming the insufficiency of an association between adolescent idiopathic scoliosis and the single-nucleotide polymorphism of the growth hormone receptor and IGF-1 genes in Han Chinese.
Orthopedics 07/2009; 32(6):411. · 2.66 Impact Factor
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ABSTRACT: IL-10 production by Th17 cells is critical for limiting autoimmunity and inflammatory responses. Gene array analysis on Stat6 and T-bet double-deficient Th17 cells identified the Th2 transcription factor c-Maf to be synergistically up-regulated by IL-6 plus TGFbeta and associated with Th17 IL-10 production. Both c-Maf and IL-10 induction during Th17 polarization depended on Stat3, but not Stat6 or Stat1, and mechanistically differed from IL-10 regulation by Th2 or IL-27 signals. TGFbeta was also synergistic with IL-27 to induce c-Maf, and it induced Stat1-independent IL-10 expression in contrast to IL-27 alone. Retroviral transduction of c-Maf was able to induce IL-10 expression in Stat6-deficient CD4 and CD8 T cells, and c-Maf directly transactivated IL-10 gene expression through binding to a MARE (Maf recognition element) motif in the IL-10 promoter. Taken together, these data reveal a novel role for c-Maf in regulating T effector development, and they suggest that TGFbeta may antagonize Th17 immunity by IL-10 production through c-Maf induction.
The Journal of Immunology 06/2009; 182(10):6226-36. · 5.79 Impact Factor
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ABSTRACT: A genetic association study of tryptophan hydroxylase 1 gene (TPH1) and arylalkylamine N-acetyltransferase gene(AANAT) with adolescent idiopathic scoliosis (AIS) in Han Chinese.
To access whether TPH1 and AANAT polymorphisms are associated with the predisposition, gender, and/or severity of AIS.
Studies have shown that AIS is a multifactorial inheritance disease, but the etiology is still unknown. In addition, several lines of evidence show that melatonin deficiency is closely associated with AIS, although there are still doubts and debates. Some polymorphisms in TPH1 and AANAT, the genes of 2 critical enzymes involved in melatonin biosynthesis, may contribute to variability of melatonin production in pineal glands.
We genotyped 16 reported single nuclear polymorphisms (SNPs) present in TPH1 and AANAT in 103 AIS patients and 108 controls with matched sex and age. The data of 6 SNPs with minor allele frequence (MAF) above 5% were analyzed by the allelic and genotypic association analysis, the genotype-phenotype (gender and Cobb angle) association analysis, and the haplotype analysis.
The single SNP analysis showed that rs10488682, located in the promoter region of TPH1, was related with the occurrence of AIS (P < 0.05). No SNP was found to be correlated with gender or Cobb angle. Two makers (rs8176799 and rs2108977) in TPH1 were found to be in strong LD [ D' = 1.0 (95% CI, 0.9-1.0), gamma = 0.501, LOD = 18.93] in the controls. Both global haplotype analysis and individual haplotype analysis showed that there was no haplotype significantly associated with AIS in this LD block.
TPH1 polymorphisms were associated with AIS but not with gender and Cobb angle in AIS patients. AANAT polymorphisms were not associated with AIS. These results suggested that TPH1 was an AIS predisposition gene, and there was a close relationship between the dyssynthesis of melatonin and AIS.
Spine 10/2008; 33(20):2199-203. · 2.08 Impact Factor
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ABSTRACT: To compare the expression of cytokines and core protein of proteoglycan in the scoliotic concave and convex cartilaginous endplate using immunohistochemical staining.
To define the possible role of transforming growth factor beta 1 (TGFbeta1), basic fibroblast growth factor (bFGF), and core protein of proteoglycan in the development of adolescent idiopathic scoliosis.
Changes in the endplate composition have been implicated as possible etiologic factors in the pathogenesis of adolescent idiopathic scoliosis. Cytokines have exclusive effects on cartilage. Thus comparing the expression of the cytokines and matrix on the convex and concave sides of scoliotic endplate tissues may help to understand the role of endplate tissues in the induction and/or progression of idiopathic scoliosis.
The convex and concave half of cartilage endplate was collected at the apex and end vertebrae from 12 patients. The expression of TGFbeta1, bFGF, and core protein on both sides was examined with the immunohistochemistry method, and results were analyzed with the image analysis system.
TGFbeta1, bFGF, and core protein of proteoglycan were all expressed in the cytoplasm of chondrocytes in the cartilaginous endplate. The area density and quantity density of TGFbeta1 and bFGF on the concave side are expressed in an even significantly higher level than that on the convex side (P > or = 0.05). The expression of the core protein of proteoglycan on the convex side is higher than that on the concave side, the difference is not significant (P > 0.05).
There was a significantly higher expression of TGFbeta1 and bFGF, although a lower expression of the core protein on the concave side, which suggests a possible etiological factor or a secondary change in the development of adolescent idiopathic scoliosis.
Spine 10/2005; 30(17):1973-8. · 2.08 Impact Factor
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ABSTRACT: Epoxide functions were successfully bonded onto the surfaces of nitric acid-oxidized PAN-based high-strength carbon fibers by reacting surface acidic functions with epichlorohydrin. A two-stage process that included ring opening and ring closure under anhydrous conditions was employed to avoid polymer formation on the surface. Typically, more than 30 μeq of epoxy groups were bound to one gram of fibers (7-micron diameters), which initially had 60 μeq of acidic groups. The first reliable method was also developed to quantitatively analyze epoxy groups on fiber surfaces using HBr and a bromide-selective electrode. The measured epoxide concentrations on fiber surfaces ranged from a few μeq/g to 40 μeq/g.
Carbon. 33(5):607-616.
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ABSTRACT: Nitric acid oxidation effectively created acidic functional groups on PAN-based high-strength carbon fibers. The acidic capacities of carbon fibers increased with oxidation time. Typically, 60 minutes of oxidation created 60 μeq acidic functional groups on each gram of carbon fibers. Nitric acid oxidation also caused tensile strength decreases and fiber weight losses. By treating fibers in refluxing aqueous NaOH after nitric acid oxidation, a weakly bound layer of partially oxidized graphitic fragments was removed and this caused higher weight losses. This treatment also removed a source of interference in later analyses. The effects of aqueous NaOH treatment after oxidation on the mechanical properties (tensile strength, Izod IS, IFSS, and ILSS) of fibers and their composites were also investigated.
Carbon.
