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Sample records for renders platelet-derived growth

  1. Association assessment of platelet derived growth factor B gene ...

    African Journals Online (AJOL)

    Background: Coronary artery disease (CAD) is the most frequent cause of morbidity and mortality in the world and it is known as a multifactorial disorder which is influenced by both genetic and environmental factors. Based on different assays, the platelet derived growth factor B (PDGF-B) gene is shown to be amongst the ...

  2. Purification of human platelet-derived growth factor

    International Nuclear Information System (INIS)

    Raines, E.W.; Ross, R.

    1985-01-01

    The paper describes a method for purification of human platelet-derived growth factor (PDGF) from outdated platelet-rich plasma (PRP) using commonly available laboratory reagents and yielding a mitogen purified 800,000-fold over the starting material. [ 3 H]thymidine incorporation into DNA of cultured cells responsive to PDGF represents the most readily available method to follow its purification and define the biological activity of a purified preparation. Other assays to quantitate PDGF include radioreceptor assay and radioimmunoassay

  3. Platelet-derived growth factor inhibits platelet activation in heparinized whole blood.

    Science.gov (United States)

    Selheim, F; Holmsen, H; Vassbotn, F S

    1999-08-15

    We previously have demonstrated that human platelets have functionally active platelet-derived growth factor alpha-receptors. Studies with gel-filtered platelets showed that an autocrine inhibition pathway is transduced through this tyrosine kinase receptor during platelet activation. The physiological significance of this inhibitory effect of platelet-derived growth factor on gel-filtered platelets activation is, however, not known. In the present study, we investigated whether platelet-derived growth factor inhibits platelet activation under more physiological conditions in heparinized whole blood, which represents a more physiological condition than gel-filtered platelets. Using flow cytometric assays, we demonstrate here that platelet-derived growth factor inhibits thrombin-, thrombin receptor agonist peptide SFLLRN-, and collagen-induced platelet aggregation and shedding of platelet-derived microparticles from the platelet plasma membrane during platelet aggregation in stirred heparinized whole blood. The inhibitory effect of platelet-derived growth factor was dose dependent. However, under nonaggregating conditions (no stirring), we could not demonstrate any significant effect of platelet-derived growth factor on thrombin- and thrombin receptor agonist peptide-induced platelet surface expression of P-selectin. Our results demonstrate that platelet-derived growth factor appears to be a true antithrombotic agent only under aggregating conditions in heparinized whole blood.

  4. Signal transduction by the platelet-derived growth factor receptor

    International Nuclear Information System (INIS)

    Williams, L.T.; Escobedo, J.A.; Keating, M.T.; Coughlin, S.R.

    1988-01-01

    The mitogenic effects of platelet-derived growth factor (PDGF) are mediated by the PDGF receptor. The mouse PDGF receptor was recently purified on the basis of its ability to become tyrosine phosphorylated in response to the A-B human platelet form of PDGF, and the receptor amino acid sequence was determined from a full-length cDNA clone. Both the human and mouse receptor cDNA sequences have been expressed in Chinese hamster ovary fibroblast (CHO) cells that normally lack PDGF receptors. This paper summarizes recent results using this system to study signal transduction by the PDGF receptor. Some of the findings show that the KI domain of the PDGF receptor plays an important role in the stimulation of DNA synthesis by PDGF. Surprisingly, the kinase insert region is not essential for PDGF stimulation of PtdIns turnover, pH change, increase in cellular calcium, and receptor autophosphorylation. In addition, PDGF stimulates a conformational change in the receptor

  5. Serum platelet-derived growth factor and fibroblast growth factor in patients with benign and malignant ovarian tumors

    DEFF Research Database (Denmark)

    Madsen, Christine Vestergaard; Steffensen, Karina Dahl; Olsen, Dorte Aalund

    2012-01-01

    New biological markers with predictive or prognostic value are highly warranted in the treatment of ovarian cancer. The platelet-derived growth factor (PDGF) system and fibroblast growth factor (FGF) system are important components in tumor growth and angiogenesis....

  6. A bioactive molecule in a complex wound healing process: platelet-derived growth factor.

    Science.gov (United States)

    Kaltalioglu, Kaan; Coskun-Cevher, Sule

    2015-08-01

    Wound healing is considered to be particularly important after surgical procedures, and the most important wounds related to surgical procedures are incisional, excisional, and punch wounds. Research is ongoing to identify methods to heal non-closed wounds or to accelerate wound healing; however, wound healing is a complex process that includes many biological and physiological events, and it is affected by various local and systemic factors, including diabetes mellitus, infection, ischemia, and aging. Different cell types (such as platelets, macrophages, and neutrophils) release growth factors during the healing process, and platelet-derived growth factor is a particularly important mediator in most stages of wound healing. This review explores the relationship between platelet-derived growth factor and wound healing. © 2014 The International Society of Dermatology.

  7. Inhibition of platelet-derived growth factor signaling prevents muscle fiber growth during skeletal muscle hypertrophy.

    Science.gov (United States)

    Sugg, Kristoffer B; Korn, Michael A; Sarver, Dylan C; Markworth, James F; Mendias, Christopher L

    2017-03-01

    The platelet-derived growth factor receptors alpha and beta (PDGFRα and PDGFRβ) mark fibroadipogenic progenitor cells/fibroblasts and pericytes in skeletal muscle, respectively. While the role that these cells play in muscle growth and development has been evaluated, it was not known whether the PDGF receptors activate signaling pathways that control transcriptional and functional changes during skeletal muscle hypertrophy. To evaluate this, we inhibited PDGFR signaling in mice subjected to a synergist ablation muscle growth procedure, and performed analyses 3 and 10 days after induction of hypertrophy. The results from this study indicate that PDGF signaling is required for fiber hypertrophy, extracellular matrix production, and angiogenesis that occur during muscle growth. © 2017 Federation of European Biochemical Societies.

  8. Expression of platelet-derived growth factor and its receptors in proliferative disorders of fibroblastic origin.

    OpenAIRE

    Smits, A.; Funa, K.; Vassbotn, F. S.; Beausang-Linder, M.; af Ekenstam, F.; Heldin, C. H.; Westermark, B.; Nistér, M.

    1992-01-01

    Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of connective tissue-derived cells in vitro. Less is known about its functions in vivo, and the role of PDGF in the development of human tumors has not been clarified. The authors have investigated the occurrence of PDGF and PDGF receptors in a series of proliferative disorders of fibroblastic origin using immunohistochemical and in situ hybridization techniques. High expression of PDGF beta-receptor mRNA and protei...

  9. Safety of recombinant human platelet-derived growth factor-BB in Augment® Bone Graft

    Directory of Open Access Journals (Sweden)

    Luis A Solchaga

    2012-12-01

    Full Text Available This article discusses nonclinical and clinical data regarding the safety of recombinant human platelet-derived growth factor-BB as a component of the Augment® Bone Graft (Augment. Augment is a bone graft substitute intended to be used as an alternative to autologous bone graft in the fusion of hindfoot and ankle joints. Nonclinical studies included assessment of the pharmacokinetic profile of intravenously administered recombinant human platelet-derived growth factor-BB in rat and dog, effects of intravenous administration of recombinant human platelet-derived growth factor-BB in a reproductive and development toxicity study in rats, and chronic toxicity and carcinogenicity of Augment in a 12-month implantation model. These studies showed that systemic exposure was brief and clearance was rapid. No signs of toxicity, carcinogenicity, or tumor promotion were observed even with doses far exceeding the maximum clinical dose. Results of clinical trials (605 participants and commercial use of recombinant human platelet-derived growth factor-BB containing products indicate that these products are not associated with increased incidence of adverse events or cancer. The safety data presented provide evidence that recombinant human platelet-derived growth factor-BB is a safe therapeutic when used in combination products as a single administration during surgical procedures for bone repair and fusion. There is no evidence associating use of recombinant human platelet-derived growth factor-BB in Augment with chronic toxicity, carcinogenicity, or tumor promotion.

  10. Association of coatomer proteins with the beta-receptor for platelet-derived growth factor

    DEFF Research Database (Denmark)

    Hansen, Klaus; Rönnstrand, L; Rorsman, C

    1997-01-01

    The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we...... of intracellular vesicle transport. In order to explore the functional significance of the interaction between alpha- and beta'-COP and the PDGF receptor, a receptor mutant was made in which the conserved histidine residue 928 was mutated to an alanine residue. The mutant receptor, which was unable to bind alpha...

  11. Abnormal platelet-derived growth factor signaling accounting for lung hypoplasia in experimental congenital diaphragmatic hernia.

    Science.gov (United States)

    Dingemann, Jens; Doi, Takashi; Ruttenstock, Elke; Puri, Prem

    2010-10-01

    The pathogenesis of pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) is not fully understood. Platelet-derived growth factor A (PDGFA) and platelet-derived growth factor receptor α (PDGFRα) play a crucial role in lung development. It has been reported that PDGF induces H(2)O(2)-production and that oxidative stress may be an important mechanism for the impaired lung development in the nitrofen rat model. We hypothesized that pulmonary expression of PDGFA and PDGFRα is altered in the nitrofen induced CDH model. Pregnant rats received 100 mg nitrofen or vehicle on gestational day 9 (D9) and were sacrificed on D15, D18 or D21. RNA was extracted from fetal left lungs and mRNA levels of PDGFA and PDGFRα were determined using real-time polymerase chain reaction. Immunohistochemistry for protein expression of PDGFA and PDGFRα was performed. Pulmonary H(2)O(2) was measured colorimetrically. mRNA levels of PDGFRα at D15 (4.50 ± 0.87) and PDGFA at D18 (2.90 ± 1.38) were increased in the nitrofen group (P stress during lung development. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Are genetic variants in the platelet-derived growth factor [beta] gene associated with chronic pancreatitis?

    Science.gov (United States)

    Muddana, Venkata; Park, James; Lamb, Janette; Yadav, Dhiraj; Papachristou, Georgios I; Hawes, Robert H; Brand, Randall; Slivka, Adam; Whitcomb, David C

    2010-11-01

    Platelet-derived growth factor [beta] (PDGF-[beta]) is a major signal in proliferation and matrix synthesis through activated pancreatic stellate cells, leading to fibrosis of the pancreas. Recurrent acute pancreatitis (RAP) seems to predispose to chronic pancreatitis (CP) in some patients but not others. We tested the hypothesis that 2 known PDGF-[beta] polymorphisms are associated with progression from RAP to CP. We also tested the hypothesis that PDGF-[beta] polymorphisms in combination with environmental risk factors such as alcohol and smoking are associated with CP. Three hundred eighty-two patients with CP (n = 176) and RAP (n = 206) and 251 controls were evaluated. Platelet-derived growth factor [beta] polymorphisms +286 A/G (rs#1800818) seen in 5'-UTR and +1135 A/C (rs#1800817) in first intron were genotyped using single-nucleotide polymorphism polymerase chain reaction approach and confirmed by DNA sequencing. The genotypic frequencies for PDGF-[beta] polymorphisms in positions +286 and +1135 were found to be similar in controls and patients with RAP and CP. There was no difference in genotypic frequencies among RAP, CP, and controls in subjects in the alcohol and smoking subgroups. Known variations in the PDGF-[beta] gene do not have a significant effect on promoting or preventing fibrogenesis in pancreatitis. Further evaluation of this important pathway is warranted.

  13. Platelet-derived growth factor-C and -D in the cardiovascular system and diseases.

    Science.gov (United States)

    Lee, Chunsik; Li, Xuri

    2018-08-01

    The cardiovascular system is among the first organs formed during development and is pivotal for the formation and function of the rest of the organs and tissues. Therefore, the function and homeostasis of the cardiovascular system are finely regulated by many important molecules. Extensive studies have shown that platelet-derived growth factors (PDGFs) and their receptors are critical regulators of the cardiovascular system. Even though PDGF-C and PDGF-D are relatively new members of the PDGF family, their critical roles in the cardiovascular system as angiogenic and survival factors have been amply demonstrated. Understanding the functions of PDGF-C and PDGF-D and the signaling pathways involved may provide novel insights into both basic biomedical research and new therapeutic possibilities for the treatment of cardiovascular diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The Use of Recombinant Human Platelet-Derived Growth Factor for Maxillary Sinus Augmentation.

    Science.gov (United States)

    Kubota, Atsushi; Sarmiento, Hector; Alqahtani, Mohammed Saad; Llobell, Arturo; Fiorellini, Joseph P

    The maxillary sinus augmentation procedure has become a predictable treatment to regenerate bone for implant placement. The purpose of this study was to evaluate the effect of recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with a deproteinized cancellous bovine bone graft for sinus augmentation. The lateral window approach was used for maxillary sinuses with minimal residual bone. After a healing period of 4 months, dental implants were placed and then restored following a 2-month osseointegration period. The result demonstrated increased bone height and ISQ values and a 100% survival rate. This study indicates that the addition of rhPDGF-BB to deproteinized cancellous bovine bone accelerated the healing period in maxillary sinuses with minimal native bone.

  15. Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

    Directory of Open Access Journals (Sweden)

    Chen Qian

    Full Text Available Platelet-derived growth factor receptor alpha (PDGFRα is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures.To address the temporal requirement of Pdgfra in embryonic development.We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies.Current study showed that (i conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5 resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives.Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b if mutations / sequence variations of these regulatory elements cause these anomalies.

  16. Platelets promote osteosarcoma cell growth through activation of the platelet-derived growth factor receptor-Akt signaling axis

    OpenAIRE

    Takagi, Satoshi; Takemoto, Ai; Takami, Miho; Oh-hara, Tomoko; Fujita, Naoya

    2014-01-01

    The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the pro...

  17. Effect of platelet-derived growth factor-BB on bone formation in calvarial defects: an experimental study in rabbits

    DEFF Research Database (Denmark)

    Vikjaer, D; Blom, S; Hjørting-Hansen, E

    1997-01-01

    The effect of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) on bone healing was examined in calvarial defects in rabbits. Bicortical circular (critical size) defects were prepared in the calvarial bone of 16 rabbits. The defects were closed on the dural side and covered externally...

  18. Platelet-derived growth factor receptors in the human central nervous system : autoradiographic distribution and receptor densities in multiple sclerosis

    NARCIS (Netherlands)

    De Keyser, J; Wilczak, N

    1997-01-01

    Platelet derived growth factor (PDGF) receptors were studied in postmortem adult human brain and cervical spinal cord using autoradiography with human recombinant I-125-PDGF-BB. PDGF-BB binds to the three different dimers of PDGF receptors (alpha alpha, alpha beta and beta beta) PDGF receptors were

  19. Molecular cloning and functional characterization of the human platelet-derived growth factor alpha receptor gene promoter

    NARCIS (Netherlands)

    Afink, G. B.; Nistér, M.; Stassen, B. H.; Joosten, P. H.; Rademakers, P. J.; Bongcam-Rudloff, E.; van Zoelen, E. J.; Mosselman, S.

    1995-01-01

    Expression of the platelet-derived growth factor alpha receptor (PDGF alpha R) is strictly regulated during mammalian development and tumorigenesis. The molecular mechanisms involved in the specific regulation of PDGF alpha R expression are unknown, but transcriptional regulation of the PDGF alpha R

  20. Notch signaling regulates platelet-derived growth factor receptor-β expression in vascular smooth muscle cells

    NARCIS (Netherlands)

    Jin, S.; Hansson, E.M.; Tikka, S.; Lanner, F.; Sahlgren, C.; Farnebo, F.; Baumann, M.; Kalimo, H.; Lendahl, U.

    2008-01-01

    Notch signaling is critically important for proper architecture of the vascular system, and mutations in NOTCH3 are associated with CADASIL, a stroke and dementia syndrome with vascular smooth muscle cell (VSMC) dysfunction. In this report, we link Notch signaling to platelet-derived growth factor

  1. Expression of platelet-derived growth factor and its receptors in proliferative disorders of fibroblastic origin.

    Science.gov (United States)

    Smits, A; Funa, K; Vassbotn, F S; Beausang-Linder, M; af Ekenstam, F; Heldin, C H; Westermark, B; Nistér, M

    1992-03-01

    Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of connective tissue-derived cells in vitro. Less is known about its functions in vivo, and the role of PDGF in the development of human tumors has not been clarified. The authors have investigated the occurrence of PDGF and PDGF receptors in a series of proliferative disorders of fibroblastic origin using immunohistochemical and in situ hybridization techniques. High expression of PDGF beta-receptor mRNA and protein was found in the malignant tumors, and also in some benign lesions, such as dermatofibroma. In all these cases, benign as well as malignant, the PDGF B-chain mRNA, and less clearly, the PDGF A-chain mRNA, were coexpressed with the beta-receptor. In contrast, high expression of PDGF alpha-receptor mRNA was only found in fully malignant lesions, i.e., malignant fibrous histiocytoma. These data indicate that an autocrine growth stimulation via the PDGF beta-receptor could occur in an early phase of tumorigenesis, and may be a necessary but insufficient event for the progression into fully malignant human connective tissue lesions.

  2. Inhibition of the mitogenic response to platelet-derived growth factor by terbinafine

    International Nuclear Information System (INIS)

    St Denny, I.H.; Glinka, K.G.; Nemecek, G.M.; Stuetz, A.

    1987-01-01

    Terbinafine (T;(E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic which inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated mitogenesis. The inclusion of 1.5-5μM T in fibroblast incubation media was associated with increased [ 3 H]thymidine incorporation into DNA in the presence and absence of PDGF. However, T at concentrations above 6μM reduced DNA synthesis in control and PDGF-exposed cultures to nearly undetectable levels. Under a phase-contrast microscope, fibroblasts appeared morphologically normal at T concentrations as high as 25 μM. Neither the uptake of [ 3 H]thymidine nor the specific binding of 125 I-PDGF to fibroblast receptors was significantly affected by 10 μM T. Furthermore, concentrations of T which antagonized the mitogenic response to PDGF also interfered with fibroblast growth factor-induced mitogenesis. Together, these data suggest that T has the ability to inhibit the in vitro action of PDGF via a post-receptor mechanism

  3. Inhibition of the mitogenic response to platelet-derived growth factor by terbinafine

    Energy Technology Data Exchange (ETDEWEB)

    St. Denny, I.H.; Glinka, K.G.; Nemecek, G.M. (Sandoz Research Institute, East Hanover, NJ (USA)); Stuetz, A. (Sandoz Forschungsinstitut, Vienna (Austria))

    1987-05-01

    Terbinafine (T;(E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic which inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated mitogenesis. The inclusion of 1.5-5{mu}M T in fibroblast incubation media was associated with increased ({sup 3}H)thymidine incorporation into DNA in the presence and absence of PDGF. However, T at concentrations above 6{mu}M reduced DNA synthesis in control and PDGF-exposed cultures to nearly undetectable levels. Under a phase-contrast microscope, fibroblasts appeared morphologically normal at T concentrations as high as 25 {mu}M. Neither the uptake of ({sup 3}H)thymidine nor the specific binding of {sup 125}I-PDGF to fibroblast receptors was significantly affected by 10 {mu}M T. Furthermore, concentrations of T which antagonized the mitogenic response to PDGF also interfered with fibroblast growth factor-induced mitogenesis. Together, these data suggest that T has the ability to inhibit the in vitro action of PDGF via a post-receptor mechanism.

  4. Biologic effects of platelet-derived growth factor receptor α blockade in uterine cancer.

    Science.gov (United States)

    Roh, Ju-Won; Huang, Jie; Hu, Wei; Yang, XiaoYun; Jennings, Nicholas B; Sehgal, Vasudha; Sohn, Bo Hwa; Han, Hee Dong; Lee, Sun Joo; Thanapprapasr, Duangmani; Bottsford-Miller, Justin; Zand, Behrouz; Dalton, Heather J; Previs, Rebecca A; Davis, Ashley N; Matsuo, Koji; Lee, Ju-Seog; Ram, Prahlad; Coleman, Robert L; Sood, Anil K

    2014-05-15

    Platelet-derived growth factor receptor α (PDGFRα) expression is frequently observed in many kinds of cancer and is a candidate for therapeutic targeting. This preclinical study evaluated the biologic significance of PDGFRα and PDGFRα blockade (using a fully humanized monoclonal antibody, 3G3) in uterine cancer. Expression of PDGFRα was examined in uterine cancer clinical samples and cell lines, and biologic effects of PDGFRα inhibition were evaluated using in vitro (cell viability, apoptosis, and invasion) and in vivo (orthotopic) models of uterine cancer. PDGFRα was highly expressed and activated in uterine cancer samples and cell lines. Treatment with 3G3 resulted in substantial inhibition of PDGFRα phosphorylation and of downstream signaling molecules AKT and mitogen-activated protein kinase (MAPK). Cell viability and invasive potential of uterine cancer cells were also inhibited by 3G3 treatment. In orthotopic mouse models of uterine cancer, 3G3 monotherapy had significant antitumor effects in the PDGFRα-positive models (Hec-1A, Ishikawa, Spec-2) but not in the PDGFRα-negative model (OVCA432). Greater therapeutic effects were observed for 3G3 in combination with chemotherapy than for either drug alone in the PDGFRα-positive models. The antitumor effects of therapy were related to increased apoptosis and decreased proliferation and angiogenesis. These findings identify PDGFRα as an attractive target for therapeutic development in uterine cancer. ©2014 American Association for Cancer Research.

  5. Synthesis and secretion of platelet-derived growth factor by human breast cancer cell lines

    International Nuclear Information System (INIS)

    Bronzert, D.A.; Pantazis, P.; Antoniades, H.N.; Kasid, A.; Davidson, N.; Dickson, R.B.; Lippman, M.E.

    1987-01-01

    The authors report that human breast cancer cells secrete a growth factor that is biologically and immunologically similar to platelet-derived growth factor (PDGF). Serum-free medium conditioned by estrogen-independent MDA-MB-231 or estrogen-dependent MCF-7 cells contains a mitogenic or competence activity that is capable of inducing incorporation of [ 3 H] thymidine into quiescent Swiss 3T3 cells in the presence of platelet-poor plasma. Like authentic PDGF, the PDGF-like activity produced by breast cancer cells is stable after acid and heat treatment (95 0 C) and inhibited by reducing agents. The mitogenic activity comigrates with a material of ≅30 kDa on NaDodSO 4 /polyacrylamide gels. Immunoprecipitation with PDGF antiserum of proteins from metabolically labeled cell lysates and conditioned medium followed by analysis on nonreducing NaDodSO 4 /polyacrylamide gels identified proteins of 30 and 34 kDa. Upon reduction, the 30- and 34-kDa bands were converted to 15- and 16-kDa bands suggesting that the immunoprecipitated proteins were made up of two disulfide-linked polypeptides similar to PDGF. Hybridization studies with cDNA probes for the A chain PDGF and the B chain of PDGF/SIS identified transcripts for both PDGF chains in the MCF-7 and MDA-MB-231 cells. The data summarized above provide conclusive evidence for the synthesis and hormonally regulated secretion of a PDGF-like mitogen by breast carcinoma cells. Production of a PDGF-like growth factor by breast cancer cell lines may be important in mediating paracrine stimulation of tumor growth

  6. Platelet-derived growth factor induces phosphorylation of a 64-kDa nuclear protein

    International Nuclear Information System (INIS)

    Shawver, L.K.; Pierce, G.F.; Kawahara, R.S.; Deuel, T.F.

    1989-01-01

    The platelet-derived growth factor (PDGF) stimulated the phosphorylation of a nuclear protein of 64 kDa (pp64) in nuclei of nontransformed normal rat kidney (NRK) cells. Low levels of phosphorylation of pp64 were observed in nuclei of serum-starved NRK cells. Fetal calf serum (FCS), PDGF, and homodimeric v-sis and PDGF A-chain protein enhanced the incorporation of 32P into pp64 over 4-fold within 30 min and over 8-fold within 2 h of exposure of NRK cells to the growth factors. In contrast, constitutive phosphorylation of 32P-labeled pp64 in nuclei of NRK cells transformed by the simian sarcoma virus (SSV) was high and only minimally stimulated by PDGF and FCS. 32P-Labeled pp64 was isolated from nuclei of PDGF-stimulated nontransformed NRK cells; the 32P of pp64 was labile in 1 M KOH, and pp64 was not significantly recognized by anti-phosphotyrosine antisera, suggesting that the PDGF-induced phosphorylation of pp64 occurred on serine or on threonine residues. However, pp64 from SSV-transformed NRK cell nuclei was significantly stable to base hydrolysis and was immunoprecipitated with anti-phosphotyrosine antisera, suggesting that pp64 from SSV-transformed cell nuclei is phosphorylated also on tyrosine. FCS, PDGF, and PDGF A- and B-chain homodimers thus stimulate the rapid time-dependent phosphorylation of a 64-kDa nuclear protein shortly after stimulation of responsive cells. The growth factor-stimulated phosphorylation of pp64 and the constitutive high levels of pp64 phosphorylation in cells transformed by SSV suggest important roles for pp64 and perhaps regulated nuclear protein kinases and phosphatases in cell division and proliferation

  7. Platelets promote osteosarcoma cell growth through activation of the platelet-derived growth factor receptor-Akt signaling axis.

    Science.gov (United States)

    Takagi, Satoshi; Takemoto, Ai; Takami, Miho; Oh-Hara, Tomoko; Fujita, Naoya

    2014-08-01

    The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the proliferation of osteosarcomas. Co-culture of platelets with MG63 or HOS osteosarcoma cells, which could induce platelet aggregation, enhanced the proliferation of each cell line in vitro. Analysis of phospho-antibody arrays revealed that co-culture of MG63 cells with platelets induced the phosphorylation of platelet derived growth factor receptor (PDGFR) and Akt. The addition of supernatants of osteosarcoma-platelet reactants also increased the growth of MG63 and HOS cells as well as the level of phosphorylated-PDGFR and -Akt. Sunitinib or LY294002, but not erlotinib, significantly inhibited the platelet-induced proliferation of osteosarcoma cells, indicating that PDGF released from platelets plays an important role in the proliferation of osteosarcomas by activating the PDGFR and then Akt. Our results suggest that inhibitors that specifically target osteosarcoma-platelet interactions may eradicate osteosarcomas. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  8. Platelet-Derived Growth Factor BB Influences Muscle Regeneration in Duchenne Muscle Dystrophy.

    Science.gov (United States)

    Piñol-Jurado, Patricia; Gallardo, Eduard; de Luna, Noemi; Suárez-Calvet, Xavier; Sánchez-Riera, Carles; Fernández-Simón, Esther; Gomis, Clara; Illa, Isabel; Díaz-Manera, Jordi

    2017-08-01

    Duchenne muscular dystrophy (DMD) is characterized by a progressive loss of muscle fibers, and their substitution by fibrotic and adipose tissue. Many factors contribute to this process, but the molecular pathways related to regeneration and degeneration of muscle are not completely known. Platelet-derived growth factor (PDGF)-BB belongs to a family of growth factors that regulate proliferation, migration, and differentiation of mesenchymal cells. The role of PDGF-BB in muscle regeneration in humans has not been studied. We analyzed the expression of PDGF-BB in muscle biopsy samples from controls and patients with DMD. We performed in vitro experiments to understand the effects of PDGF-BB on myoblasts involved in the pathophysiology of muscular dystrophies and confirmed our results in vivo by treating the mdx murine model of DMD with repeated i.m. injections of PDGF-BB. We observed that regenerating and necrotic muscle fibers in muscle biopsy samples from DMD patients expressed PDGF-BB. In vitro, PDGF-BB attracted myoblasts and activated their proliferation. Analysis of muscles from the animals treated with PDGF-BB showed an increased population of satellite cells and an increase in the number of regenerative fibers, with a reduction in inflammatory infiltrates, compared with those in vehicle-treated mice. Based on our results, PDGF-BB may play a protective role in muscular dystrophies by enhancing muscle regeneration through activation of satellite cell proliferation and migration. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  9. Platelet-derived growth factor predicts prolonged relapse-free period in multiple sclerosis.

    Science.gov (United States)

    Stampanoni Bassi, Mario; Iezzi, Ennio; Marfia, Girolama A; Simonelli, Ilaria; Musella, Alessandra; Mandolesi, Georgia; Fresegna, Diego; Pasqualetti, Patrizio; Furlan, Roberto; Finardi, Annamaria; Mataluni, Giorgia; Landi, Doriana; Gilio, Luana; Centonze, Diego; Buttari, Fabio

    2018-04-14

    In the early phases of relapsing-remitting multiple sclerosis (RR-MS), a clear correlation between brain lesion load and clinical disability is often lacking, originating the so-called clinico-radiological paradox. Different factors may contribute to such discrepancy. In particular, synaptic plasticity may reduce the clinical expression of brain damage producing enduring enhancement of synaptic strength largely dependent on neurotrophin-induced protein synthesis. Cytokines released by the immune cells during acute inflammation can alter synaptic transmission and plasticity possibly influencing the clinical course of MS. In addition, immune cells may promote brain repair during the post-acute phases, by secreting different growth factors involved in neuronal and oligodendroglial cell survival. Platelet-derived growth factor (PDGF) is a neurotrophic factor that could be particularly involved in clinical recovery. Indeed, PDGF promotes long-term potentiation of synaptic activity in vitro and in MS and could therefore represent a key factor improving the clinical compensation of new brain lesions. The aim of the present study is to explore whether cerebrospinal fluid (CSF) PDGF concentrations at the time of diagnosis may influence the clinical course of RR-MS. At the time of diagnosis, we measured in 100 consecutive early MS patients the CSF concentrations of PDGF, of the main pro- and anti-inflammatory cytokines, and of reliable markers of neuronal damage. Clinical and radiological parameters of disease activity were prospectively collected during follow-up. CSF PDGF levels were positively correlated with prolonged relapse-free survival. Radiological markers of disease activity, biochemical markers of neuronal damage, and clinical parameters of disease progression were instead not influenced by PDGF concentrations. Higher CSF PDGF levels were associated with an anti-inflammatory milieu within the central nervous system. Our results suggest that PDGF could promote a

  10. Observations on human smooth muscle cell cultures from hyperplastic lesions of prosthetic bypass grafts: Production of a platelet-derived growth factor-like mitogen and expression of a gene for a platelet-derived growth factor receptor--a preliminary study

    International Nuclear Information System (INIS)

    Birinyi, L.K.; Warner, S.J.; Salomon, R.N.; Callow, A.D.; Libby, P.

    1989-01-01

    Prosthetic bypass grafts placed to the distal lower extremity often fail because of an occlusive tissue response in the perianastomotic region. The origin of the cells that comprise this occlusive lesion and the causes of the cellular proliferation are not known. To increase our understanding of this process we cultured cells from hyperplastic lesions obtained from patients at the time of reexploration for lower extremity graft failure, and we studied their identity and growth factor production in tissue culture. These cultures contain cells that express muscle-specific actin isoforms, shown by immunohistochemical staining, consistent with vascular smooth muscle origin. These cultures also released material that stimulated smooth muscle cell growth. A portion of this activity was similar to platelet-derived growth factor, since preincubation with antibody-to-human platelet-derived growth factor partially blocked the mitogenic effect of medium conditioned by human anastomotic hyperplastic cells. These conditioned media also contained material that competed with platelet-derived growth factor for its receptor, as measured in a radioreceptor assay. Northern blot analysis showed that these cells contain messenger RNA that encodes the A chain but not the B chain of platelet-derived growth factor. In addition, these cells contain messenger RNA that encodes a platelet-derived growth factor receptor. We conclude that cultured smooth muscle cells from human anastomotic hyperplastic lesions express genes for platelet-derived growth factor A chain and a platelet-derived growth factor receptor and secrete biologically active molecules similar to platelet-derived growth factor

  11. Reversion of autocrine transformation by a dominant negative platelet-derived growth factor mutant.

    Science.gov (United States)

    Vassbotn, F S; Andersson, M; Westermark, B; Heldin, C H; Ostman, A

    1993-07-01

    A non-receptor-binding mutant of the platelet-derived growth factor (PDGF) A chain, PDGF-0, was generated by exchanging 7 amino acids in the sequence. The mutant chains formed dimers that were similar to wild-type PDGF-AA with regard to stability and rate of processing to the mature 30-kDa secreted forms. Moreover, the mutant chains formed disulfide-bonded heterodimers with the PDGF B chain in NIH 3T3 cells heterodimer underwent the same processing and secretion as PDGF-AB. Transfection of c-sis-expressing 3T3 cells with PDGF-0 significantly inhibited the transformed phenotype of these cells, as determined by the following criteria. (i) Compared with PDGF-0-negative clones, PDGF-0-producing clones showed a reverted morphology. (ii) Clones producing PDGF-0 grew more slowly than PDGF-0-negative clones, with a fivefold difference in cell number after 14 days in culture. (iii) The expression of PDGF-0 completely inhibited the ability of the c-sis-expressing 3T3 cells to form colonies in soft agar; this inhibition was overcome by the addition of recombinant PDGF-BB to the culture medium, showing that the lack of colony formation of these cells was not due to a general unresponsiveness to PDGF. The specific expression of a PDGF-0/PDGF wild-type heterodimer in COS cells revealed that the affinity of the mutant heterodimer for the PDGF alpha receptor was decreased by approximately 50-fold compared with that of PDGF-AA. Thus, we show that a non-receptor-binding PDGF A-chain mutant neutralizes in a trans-dominant manner the autocrine transforming potential of the c-sis/PDGF B chain by forming low-affinity heterodimers with wild-type PDGF chains. This method of specifically antagonizing the effect of PDGF may be useful in investigations of the role of PDGF in normal and pathological conditions.

  12. Expression of platelet-derived growth factor B is upregulated in patients with thoracic aortic dissection.

    Science.gov (United States)

    Meng, Weixin; Liu, Shangdian; Li, Dandan; Liu, Zonghong; Yang, Hui; Sun, Bo; Liu, Hongyu

    2018-04-20

    Thoracic aortic dissection (TAD) is a serious condition requiring urgent treatment to avoid catastrophic consequences. The inflammatory response is involved in the occurrence and development of TAD, possibly potentiated by platelet-derived growth factors (PDGFs). This study aimed to determine whether expression of PDGF-B (a subunit of PDGF-BB) was increased in TAD patients and to explore the factors responsible for its upregulation and subsequent effects on TAD. Full-thickness ascending aorta wall specimens from TAD patients (n = 15) and control patients (n = 10) were examined for expression of PDGF-B and its receptor (PDGFRB) and in terms of morphology, inflammation, and fibrosis. Blood samples from TAD and control patients were collected to detect plasma levels of PDGF-BB and soluble elastins. Expression levels of PDGF-B, PDGFRB, and collagen I were significantly enhanced in ascending aorta wall specimens from TAD patients compared with controls. Furthermore, soluble elastic fragments and PDGF-BB were significantly increased in plasma from TAD patients compared with controls, and numerous irregular elastic fibers and macrophages were seen in the ascending aorta wall in TAD patients. An increase in elastic fragments in the aorta wall might be responsible for inducing the activation and migration of macrophages to injured sites, leading to elevated expression of PDGF-B, which in turn induces deposition of collagen, disrupts extracellular matrix homeostasis, and increases the stiffness of the aorta wall, resulting in compromised aorta compliance. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  13. Platelet-derived growth factor regulates K-Cl cotransport in vascular smooth muscle cells.

    Science.gov (United States)

    Zhang, Jing; Lauf, Peter K; Adragna, Norma C

    2003-03-01

    Platelet-derived growth factor (PDGF), a potent serum mitogen for vascular smooth muscle cells (VSMCs), plays an important role in membrane transport regulation and in atherosclerosis. K-Cl cotransport (K-Cl COT/KCC), the coupled-movement of K and Cl, is involved in ion homeostasis. VSMCs possess K-Cl COT activity and the KCC1 and KCC3 isoforms. Here, we report on the effect of PDGF on K-Cl COT activity and mRNA expression in primary cultures of rat VSMCs. K-Cl COT was determined as the Cl-dependent Rb influx and mRNA expression by semiquantitative RT-PCR. Twenty four-hour serum deprivation inhibited basal K-Cl COT activity. Addition of PDGF increased total protein content and K-Cl COT activity in a time-dependent manner. PDGF activated K-Cl COT in a dose-dependent manner, both acutely (10 min) and chronically (12 h). AG-1296, a selective inhibitor of the PDGF receptor tyrosine kinase, abolished these effects. Actinomycin D and cycloheximide had no effect on the acute PDGF activation of K-Cl COT, suggesting posttranslational regulation by the drug. Furthermore, PDGF increased KCC1 and decreased KCC3 mRNA expression in a time-dependent manner. These results indicate that chronic activation of K-Cl COT activity by PDGF may involve regulation of the two KCC mRNA isoforms, with KCC1 playing a dominant role in the mechanism of PDGF-mediated activation.

  14. Immunohistochemical examination of effects of kefir, koumiss and commercial probiotic capsules on platelet derived growth factor-c and platelet derived growth factor receptor-alpha expression in mouse liver and kidney.

    Science.gov (United States)

    Bakir, B; Sari, E K; Aydin, B D; Yildiz, S E

    2015-04-01

    We investigated using immunohistochemistry the effects of kefir, koumiss and commercial probiotic capsules on the expression of platelet derived growth factor-c (PDGF-C) and platelet derived growth factor receptor-alpha (PDGFR-α) in mouse liver and kidney. Mice were assigned to four groups: group 1 was given commercial probiotic capsules, group 2 was given kefir, group 3 was given koumiss and group 4 was untreated. After oral administration for 15 days, body weights were recorded and liver and kidney tissue samples were obtained. Hematoxylin and eosin staining was used to examine histology. PDGF-C and PDGFR-α in liver and kidney were localized using the streptavidin-biotin peroxidase complex method (ABC). We found that the weights of the mice in the kefir, koumiss and commercial probiotic capsules groups increased compared to the control group. No differences in liver and kidney histology were observed in any of the experimental groups. Kefir, koumiss and the commercial probiotic preparation increased PDGF-C and PDGFR-α expression.

  15. Injectable Biodegradable Polyurethane Scaffolds with Release of Platelet-derived Growth Factor for Tissue Repair and Regeneration

    Science.gov (United States)

    Hafeman, Andrea E.; Li, Bing; Yoshii, Toshitaka; Zienkiewicz, Katarzyna; Davidson, Jeffrey M.; Guelcher, Scott A.

    2013-01-01

    Purpose The purpose of this work was to investigate the effects of triisocyanate composition on the biological and mechanical properties of biodegradable, injectable polyurethane scaffolds for bone and soft tissue engineering. Methods Scaffolds were synthesized using reactive liquid molding techniques, and were characterized in vivo in a rat subcutaneous model. Porosity, dynamic mechanical properties, degradation rate, and release of growth factors were also measured. Results Polyurethane scaffolds were elastomers with tunable damping properties and degradation rates, and they supported cellular infiltration and generation of new tissue. The scaffolds showed a two-stage release profile of platelet-derived growth factor, characterized by a 75% burst release within the first 24 h and slower release thereafter. Conclusions Biodegradable polyurethanes synthesized from triisocyanates exhibited tunable and superior mechanical properties compared to materials synthesized from lysine diisocyanates. Due to their injectability, biocompatibility, tunable degradation, and potential for release of growth factors, these materials are potentially promising therapies for tissue engineering. PMID:18516665

  16. Platelet-Derived Growth Factor-Receptor α Strongly Inhibits Melanoma Growth In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Debora Faraone

    2009-08-01

    Full Text Available Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Rα may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Rα respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Rα. Proliferation was rescued by PDGF-Rα inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Rα mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Rα was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Rα show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Bα and a marked increase of p38γ, mitogen-activated protein kinase kinase 3, and signal regulatory protein α1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Rα reached a significant 70% inhibition of primary melanoma growth (P < .001 and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Rα strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

  17. Bacteria-induced release of white cell--and platelet-derived vascular endothelial growth factor in vitro

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Werther, K; Mynster, T

    2001-01-01

    BACKGROUND AND OBJECTIVES: Poor prognosis after resection of primary colorectal cancer may be related to the combination of perioperative blood transfusion and subsequent development of infectious complications. White blood cell--and platelet-derived cancer growth substances, including vascular...... endothelial growth factor (VEGF), may be involved in this process. Therefore, we studied the in vitro release of VEGF from white blood cells and platelets stimulated by bacterial antigens and supernatants from stored red cell components. MATERIALS AND METHODS: Eight units of whole blood (WB) and eight units...... of buffy-coat-depleted red cell (SAGM) blood were donated by healthy blood donors. Subsequently, half of every unit was leucocyte depleted by filtration, and all 32 half-units were stored under standard conditions for 35 days. Just after storage, and on days 7, 21 and 35 during storage, aliquots...

  18. Neer Award 2018: Platelet-derived growth factor receptor α co-expression typifies a subset of platelet-derived growth factor receptor β-positive progenitor cells that contribute to fatty degeneration and fibrosis of the murine rotator cuff.

    Science.gov (United States)

    Jensen, Andrew R; Kelley, Benjamin V; Mosich, Gina M; Ariniello, Allison; Eliasberg, Claire D; Vu, Brandon; Shah, Paras; Devana, Sai K; Murray, Iain R; Péault, Bruno; Dar, Ayelet; Petrigliano, Frank A

    2018-04-10

    After massive tears, rotator cuff muscle often undergoes atrophy, fibrosis, and fatty degeneration. These changes can lead to high surgical failure rates and poor patient outcomes. The identity of the progenitor cells involved in these processes has not been fully elucidated. Platelet-derived growth factor receptor β (PDGFRβ) and platelet-derived growth factor receptor α (PDGFRα) have previously been recognized as markers of cells involved in muscle fibroadipogenesis. We hypothesized that PDGFRα expression identifies a fibroadipogenic subset of PDGFRβ + progenitor cells that contribute to fibroadipogenesis of the rotator cuff. We created massive rotator cuff tears in a transgenic strain of mice that allows PDGFRβ + cells to be tracked via green fluorescent protein (GFP) fluorescence. We then harvested rotator cuff muscle tissues at multiple time points postoperatively and analyzed them for the presence and localization of GFP + PDGFRβ + PDGFRα + cells. We cultured, induced, and treated these cells with the molecular inhibitor CWHM-12 to assess fibrosis inhibition. GFP + PDGFRβ + PDGFRα + cells were present in rotator cuff muscle tissue and, after massive tears, localized to fibrotic and adipogenic tissues. The frequency of PDGFRβ + PDGFRα + cells increased at 5 days after massive cuff tears and decreased to basal levels within 2 weeks. PDGFRβ + PDGFRα + cells were highly adipogenic and significantly more fibrogenic than PDGFRβ + PDGFRα - cells in vitro and localized to adipogenic and fibrotic tissues in vivo. Treatment with CWHM-12 significantly decreased fibrogenesis from PDGFRβ + PDGFRα + cells. PDGFRβ + PDGFRα + cells directly contribute to fibrosis and fatty degeneration after massive rotator cuff tears in the mouse model. In addition, CWHM-12 treatment inhibits fibrogenesis from PDGFRβ + PDGFRα + cells in vitro. Clinically, perioperative PDGFRβ + PDGFRα + cell inhibition may limit rotator cuff tissue degeneration and, ultimately

  19. Use of multitarget tyrosine kinase inhibitors to attenuate platelet-derived growth factor signalling in lung disease

    Directory of Open Access Journals (Sweden)

    Rana Kanaan

    2017-10-01

    Full Text Available Platelet-derived growth factors (PDGFs and their receptors (PDGFRs play a fundamental role in the embryonic development of the lung. Aberrant PDGF signalling has been documented convincingly in a large variety of pulmonary diseases, including idiopathic pulmonary arterial hypertension, lung cancer and lung fibrosis. Targeting PDGF signalling has been proven to be effective in these diseases. In clinical practice, the most effective way to block PDGF signalling is to inhibit the activity of the intracellular PDGFR kinases. Although the mechanism of action of such drugs is not specific for PDGF signalling, the medications have a broad therapeutic index that allows clinical use. The safety profile and therapeutic opportunities of these and future medications that target PDGFs and PDGFRs are reviewed.

  20. Forced expression of platelet-derived growth factor B in the mouse cerebellar primordium changes cell migration during midline fusion and causes cerebellar ectopia

    NARCIS (Netherlands)

    Andrae, Johanna; Afink, Gijs; Zhang, Xiao-Qun; Wurst, Wolfgang; Nistér, Monica

    2004-01-01

    The platelet-derived growth factor (PDGF) and receptors are expressed in the developing central nervous system and in brain tumors. To investigate the role of PDGF during normal cerebellar development, we created transgenic mice where PDGF-B was introduced into the endogenous Engrailed1 locus (En1).

  1. Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor.

    Science.gov (United States)

    Nishimura, R; Li, W; Kashishian, A; Mondino, A; Zhou, M; Cooper, J; Schlessinger, J

    1993-11-01

    Autophosphorylation sites of growth factor receptors with tyrosine kinase activity function as specific binding sites for Src homology 2 (SH2) domains of signaling molecules. This interaction appears to be a crucial step in a mechanism by which receptor tyrosine kinases relay signals to downstream signaling pathways. Nck is a widely expressed protein consisting exclusively of SH2 and SH3 domains, the overexpression of which causes cell transformation. It has been shown that various growth factors stimulate the phosphorylation of Nck and its association with autophosphorylated growth factor receptors. A panel of platelet-derived growth factor (PDGF) receptor mutations at tyrosine residues has been used to identify the Nck binding site. Here we show that mutation at Tyr-751 of the PDGF beta-receptor eliminates Nck binding both in vitro and in living cells. Moreover, the Y751F PDGF receptor mutant failed to mediate PDGF-stimulated phosphorylation of Nck in intact cells. A phosphorylated Tyr-751 is also required for binding of phosphatidylinositol-3 kinase to the PDGF receptor. Hence, the SH2 domains of p85 and Nck share a binding site in the PDGF receptor. Competition experiments with different phosphopeptides derived from the PDGF receptor suggest that binding of Nck and p85 is influenced by different residues around Tyr-751. Thus, a single tyrosine autophosphorylation site is able to link the PDGF receptor to two distinct SH2 domain-containing signaling molecules.

  2. The detection of platelet derived growth factor using decoupling of quencher-oligonucleotide from aptamer/quantum dot bioconjugates

    International Nuclear Information System (INIS)

    Kim, Gang-Il; Sung, Yun-Mo; Kim, Kyung-Woo; Oh, Min-Kyu

    2009-01-01

    High-sensitivity, high-specificity detection of platelet derived growth factor (PDGF)-BB was realized using the change in fluorescence resonance energy transfer (FRET) occurring between quantum dot (QD) donors and black hole quencher (BHQ) acceptors. CdSe/ZnS QD/mercaptoacetic acid (MAA)/PDGF aptamer bioconjugates were successfully synthesized using ligand exchange. Black hole quencher (BHQ)-bearing oligonucleotide molecules showing partial sequence matching to PDGF aptamer were attached to PDGF aptamers and photoluminescence (PL) quenching was obtained through FRET. By adding target PDGF-BB to the bioconjugates containing BHQs, PL recovery was detected due to detachment of BHQ-bearing oligonucleotide from the PDGF aptamer as a result of the difference in affinity to the PDGF aptamer. The detection limit of the sensor was ∼0.4 nM and the linearity was maintained up to 1.6 nM in the PL intensity versus concentration curve. Measurement of PL recovery was suggested as a strong tool for high-sensitivity detection of PDGF-BB. Epidermal growth factor (EGF), the negative control molecule, did not contribute to PL recovery due to lack of binding affinity to the PDGF aptamers, which demonstrates the selectivity of the biosensor.

  3. Platelet-Derived Growth Factor (PDGF/PDGF Receptors (PDGFR Axis as Target for Antitumor and Antiangiogenic Therapy

    Directory of Open Access Journals (Sweden)

    Anca Maria Cimpean

    2010-03-01

    Full Text Available Angiogenesis in normal and pathological conditions is a multi-step process governed by positive and negative endogenous regulators. Many growth factors are involved in different steps of angiogenesis, like vascular endothelial growth factors (VEGF, fibroblast growth factor (FGF-2 or platelet-derived growth factors (PDGF. From these, VEGF and FGF-2 were extensively investigated and it was shown that they significantly contribute to the induction and progression of angiogenesis. A lot of evidence has been accumulated in last 10 years that supports the contribution of PDGF/PDGFR axis in developing angiogenesis in both normal and tumoral conditions. The crucial role of PDGF-B and PDGFR-β in angiogenesis has been demonstrated by gene targeting experiments, and their expression correlates with increased vascularity and maturation of the vascular wall. PDGF and their receptors were identified in a large variety of human tumor cells. In experimental models it was shown that inhibition of PDGF reduces interstitial fluid pressure in tumors and enhances the effect of chemotherapy. PDGFR have been involved in the cardiovascular development and their loss leads to a disruption in yolk sac blood vessels development. PDGFRβ expression by pericytes is necessary for their recruitment and integration in the wall of tumor vessels. Endothelial cells of tumor-associated blood vessels can express PDGFR. Based on these data, it was suggested the potential benefit of targeting PDGFR in the treatment of solid tumors. The molecular mechanisms of PDGF/PDGFR-mediated angiogenesis are not fully understood, but it was shown that tyrosine kinase inhibitors reduce tumor growth and angiogenesis in experimental xenograft models, and recent data demonstrated their efficacy in chemoresistant tumors. The in vivo effects of PDGFR inhibitors are more complex, based on the cross-talk with other angiogenic factors. In this review, we summarize data regarding the mechanisms and

  4. The Oligo Fucoidan Inhibits Platelet-Derived Growth Factor-Stimulated Proliferation of Airway Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Chao-Huei Yang

    2016-01-01

    Full Text Available In the pathogenesis of asthma, the proliferation of airway smooth muscle cells (ASMCs is a key factor in airway remodeling and causes airway narrowing. In addition, ASMCs are also the effector cells of airway inflammation. Fucoidan extracted from marine brown algae polysaccharides has antiviral, antioxidant, antimicrobial, anticlotting, and anticancer properties; however, its effectiveness for asthma has not been elucidated thus far. Platelet-derived growth factor (PDGF-treated primary ASMCs were cultured with or without oligo-fucoidan (100, 500, or 1000 µg/mL to evaluate its effects on cell proliferation, cell cycle, apoptosis, and Akt, ERK1/2 signaling pathway. We found that PDGF (40 ng/mL increased the proliferation of ASMCs by 2.5-fold after 48 h (p < 0.05. Oligo-fucoidan reduced the proliferation of PDGF-stimulated ASMCs by 75%–99% after 48 h (p < 0.05 and induced G1/G0 cell cycle arrest, but did not induce apoptosis. Further, oligo-fucoidan supplementation reduced PDGF-stimulated extracellular signal-regulated kinase (ERK1/2, Akt, and nuclear factor (NF-κB phosphorylation. Taken together, oligo-fucoidan supplementation might reduce proliferation of PDGF-treated ASMCs through the suppression of ERK1/2 and Akt phosphorylation and NF-κB activation. The results provide basis for future animal experiments and human trials.

  5. Platelet-derived-growth-factor-induced signalling in human platelets: phosphoinositide-3-kinase-dependent inhibition of platelet activation.

    Science.gov (United States)

    Selheim, F; Fukami, M H; Holmsen, H; Vassbotn, F S

    2000-09-01

    Human platelets release platelet-derived growth factor (PDGF) from alpha-granules during platelet activation. We have previously shown that platelets have PDGF alpha-receptors, a transmembrane tyrosine kinase that takes part in negative feedback regulation during platelet activation. Here we have described a study of PDGF-induced tyrosine phosphorylation of platelet substrates and phosphoinositide 3-kinase (PI-3K) activity in collagen-stimulated platelets. By immunoblotting with phosphotyrosine antibodies of collagen-activated platelets we found that PDGF increased the phosphorylation of several platelet substrates, e.g. pp140, pp120 and pp85. PDGF inhibited collagen-induced platelet activation in the presence of inhibitors of autocrine stimulation, thus blocking the pure collagen-induced signal transduction. PDGF enhanced the collagen-induced formation of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) as measured by HPLC. Wortmannin and LY294002, two unrelated inhibitors of PI-3K, were used to investigate the role of PI-3K in PDGF-induced platelet signalling. Incubation of platelets with wortmannin and LY294002 blocked the formation of three phosphorylated inositides as well as the inhibitory effect of PDGF on collagen-induced platelet activation. We conclude that the inhibitory effect of PDGF on platelet activation is PI-3K dependent. This is the first demonstration of a negative regulatory function of 3-phosphorylated inositides in platelets.

  6. Terbinafine: effects on platelet-derived growth factor-stimulated smooth muscle cells in vitro and myointimal proliferation in vivo

    International Nuclear Information System (INIS)

    McCarthy, L.; Van Halen, R.G.; St Denny, I.H.; Glinka, K.G.; Handley, D.A.; Stuetz, A.; Nemecek, G.M.

    1987-01-01

    Terbinafine (T; (E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic agent with antimitogenic activity in fibroblasts, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated aortic smooth muscle cell DNA synthesis in vitro and myointimal proliferation in vivo. Exposure of smooth muscle cells to 1-25 μM T resulted in a concentration-dependent inhibition of PDGF-induced mitogenesis as determined by [ 3 H]thymidine incorporation or cell number. The IC 50 for T was approximately 5 μM. The inhibitory effect of terbinafine persisted in the presence of 0.4-8.0 μg/ml cholesterol or 130 μg/ml mevalonate. Administration of T to rats for 2 d before and 14 d after balloon catheter carotid injury resulted in a 40% decrease in lesion area. These observations indicate that T is both a potent in vitro antagonist of the smooth muscle cell mitogenic response to PDGF and an effective, well-tolerated, orally active inhibitor of myointimal proliferation in vivo

  7. Morphine induces expression of platelet-derived growth factor in human brain microvascular endothelial cells: implication for vascular permeability.

    Directory of Open Access Journals (Sweden)

    Hongxiu Wen

    Full Text Available Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Morphine, often abused by HIV-infected patients, is known to accelerate neuroinflammation associated with HIV-1 infection. Detailed molecular mechanisms of morphine action however, remain poorly understood. Platelet-derived growth factor (PDGF has been implicated in a number of pathological conditions, primarily due to its potent mitogenic and permeability effects. Whether morphine exposure results in enhanced vascular permeability in brain endothelial cells, likely via induction of PDGF, remains to be established. In the present study, we demonstrated morphine-mediated induction of PDGF-BB in human brain microvascular endothelial cells, an effect that was abrogated by the opioid receptor antagonist-naltrexone. Pharmacological blockade (cell signaling and loss-of-function (Egr-1 approaches demonstrated the role of mitogen-activated protein kinases (MAPKs, PI3K/Akt and the downstream transcription factor Egr-1 respectively, in morphine-mediated induction of PDGF-BB. Functional significance of increased PDGF-BB manifested as increased breach of the endothelial barrier as evidenced by decreased expression of the tight junction protein ZO-1 in an in vitro model system. Understanding the regulation of PDGF expression may provide insights into the development of potential therapeutic targets for intervention of morphine-mediated neuroinflammation.

  8. Terbinafine: effects on platelet-derived growth factor-stimulated smooth muscle cells in vitro and myointimal proliferation in vivo

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, L.; Van Halen, R.G.; St. Denny, I.H.; Glinka, K.G.; Handley, D.A.; Stuetz, A.; Nemecek, G.M.

    1987-05-01

    Terbinafine (T; (E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic agent with antimitogenic activity in fibroblasts, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated aortic smooth muscle cell DNA synthesis in vitro and myointimal proliferation in vivo. Exposure of smooth muscle cells to 1-25 ..mu..M T resulted in a concentration-dependent inhibition of PDGF-induced mitogenesis as determined by (/sup 3/H)thymidine incorporation or cell number. The IC/sub 50/ for T was approximately 5 ..mu..M. The inhibitory effect of terbinafine persisted in the presence of 0.4-8.0 ..mu..g/ml cholesterol or 130 ..mu..g/ml mevalonate. Administration of T to rats for 2 d before and 14 d after balloon catheter carotid injury resulted in a 40% decrease in lesion area. These observations indicate that T is both a potent in vitro antagonist of the smooth muscle cell mitogenic response to PDGF and an effective, well-tolerated, orally active inhibitor of myointimal proliferation in vivo.

  9. Platelet-derived growth factor-DD targeting arrests pathological angiogenesis by modulating glycogen synthase kinase-3beta phosphorylation.

    Science.gov (United States)

    Kumar, Anil; Hou, Xu; Lee, Chunsik; Li, Yang; Maminishkis, Arvydas; Tang, Zhongshu; Zhang, Fan; Langer, Harald F; Arjunan, Pachiappan; Dong, Lijin; Wu, Zhijian; Zhu, Linda Y; Wang, Lianchun; Min, Wang; Colosi, Peter; Chavakis, Triantafyllos; Li, Xuri

    2010-05-14

    Platelet-derived growth factor-DD (PDGF-DD) is a recently discovered member of the PDGF family. The role of PDGF-DD in pathological angiogenesis and the underlying cellular and molecular mechanisms remain largely unexplored. In this study, using different animal models, we showed that PDGF-DD expression was up-regulated during pathological angiogenesis, and inhibition of PDGF-DD suppressed both choroidal and retinal neovascularization. We also demonstrated a novel mechanism mediating the function of PDGF-DD. PDGF-DD induced glycogen synthase kinase-3beta (GSK3beta) Ser(9) phosphorylation and Tyr(216) dephosphorylation in vitro and in vivo, leading to increased cell survival. Consistently, GSK3beta activity was required for the antiangiogenic effect of PDGF-DD targeting. Moreover, PDGF-DD regulated the expression of GSK3beta and many other genes important for angiogenesis and apoptosis. Thus, we identified PDGF-DD as an important target gene for antiangiogenic therapy due to its pleiotropic effects on vascular and non-vascular cells. PDGF-DD inhibition may offer new therapeutic options to treat neovascular diseases.

  10. A Tumor Suppressor Gene Product, Platelet-Derived Growth Factor Receptor-Like Protein Controls Chondrocyte Proliferation and Differentiation.

    Science.gov (United States)

    Kawata, Kazumi; Kubota, Satoshi; Eguchi, Takanori; Aoyama, Eriko; Moritani, Norifumi H; Oka, Morihiko; Kawaki, Harumi; Takigawa, Masaharu

    2017-11-01

    The platelet-derived growth factor receptor-like (PDGFRL) gene is regarded as a tumor suppressor gene. However, nothing is known about the molecular function of PDGFRL. In this study, we initially clarified its function in chondrocytes. Among all cell lines examined, the PDGFRL mRNA level was the highest in chondrocytic HCS-2/8 cells. Interestingly, the proliferation of chondrocytic HCS-2/8 cells was promoted by PDGFRL overexpression, whereas that of the breast cancer-derived MDA-MB-231 cells was inhibited. Of note, in PDGFRL-overexpressing HCS-2/8 cells, the expression of chondrocyte differentiation marker genes, SOX9, ACAN, COL2A1, COL10A1, and ALP, was decreased. Moreover, we confirmed the expression of PDGFRL mRNA in normal cartilage tissue and chondrocytes. Eventually, the expression of PDGFRL mRNA in condrocytes except in the case of hypertrophic chondrocytes was demonstrated in vivo and in vitro. These findings suggest that PDGFRL plays the different roles, depending upon cell types. Particularly, in chondrocytes, PDGFRL may play a new and important role which is distinct from the function previously reported. J. Cell. Biochem. 118: 4033-4044, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Evidence that platelet-derived growth factor may be a novel endogenous pyrogen in the central nervous system.

    Science.gov (United States)

    Pelá, I R; Ferreira, M E; Melo, M C; Silva, C A; Coelho, M M; Valenzuela, C F

    2000-05-01

    Platelet-derived growth factor (PDGF) exerts neurotrophic and neuromodulatory actions in the mammalian central nervous system (CNS). Like the cytokines, PDGF primarily signals through tyrosine phosphorylation-dependent pathways that activate multiple intracellular molecules including Janus family kinases. We previously showed that microinjection of PDGF-BB into the lateral ventricle induced a febrile response in rats that was reduced by pretreatment with Win 41662, a potent inhibitor of PDGF receptors (Pelá IR, Ferreira MES, Melo MCC, Silva CAA, and Valenzuela CF. Ann NY Acad Sci 856: 289-293, 1998). In this study, we further characterized the role of PDGF-BB in the febrile response in rats. Microinjection of PDGF-BB into the third ventricle produced a dose-dependent increase in colonic temperature that peaked 3-4 h postinjection. Win 41662 attenuated fever induced by intraperitoneal injection of bacterial lipopolysaccharide, suggesting that endogenous PDGF participates in the febrile response to this exogenous pyrogen. Importantly, febrile responses induced by tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 were unchanged by Win 41662. Both indomethacin and dexamethasone blocked the PDGF-BB-induced increase in colonic temperature, and, therefore, we postulate that PDGF-BB may act via prostaglandin- and/or inducible enzyme-dependent pathways. Thus our findings suggest that PDGF-BB is an endogenous CNS mediator of the febrile response in rats.

  12. Human histologic evaluation of anorganic bovine bone mineral combined with recombinant human platelet-derived growth factor BB in maxillary sinus augmentation: case series study.

    Science.gov (United States)

    Nevins, Myron; Garber, David; Hanratty, James J; McAllister, Bradley S; Nevins, Marc L; Salama, Maurice; Schupbach, Peter; Wallace, Steven; Bernstein, Simon M; Kim, David M

    2009-12-01

    The objective of this proof-of-principle study was to examine the potential for improved bone regenerative outcomes in maxillary sinus augmentation procedures when recombinant human platelet-derived growth factor BB (0.3 mg/mL) is combined with particulate anorganic bovine bone mineral. The surgical outcomes in all treated sites were uneventful at 6 to 8 months, with sufficient regenerated bone present to allow successful placement of maxillary posterior implants. Large areas of dense, well-formed lamellar bone were seen throughout the intact core specimens in more than half of the grafted sites. Abundant numbers of osteoblasts were noted in concert with significant osteoid in all sites, indicating ongoing osteogenesis. A number of cores demonstrated efficient replacement of the normally slowly resorbing anorganic bovine bone mineral matrix particles with newly formed bone when the matrix was saturated with recombinant human platelet-derived growth factor BB.

  13. Elevated platelet-derived growth factor-BB concentrations in premature neonates who develop chronic lung disease

    Directory of Open Access Journals (Sweden)

    Adcock Kim G

    2004-06-01

    Full Text Available Abstract Background Chronic lung disease (CLD in the preterm newborn is associated with inflammation and fibrosis. Platelet-derived growth factor-BB (PDGF-BB, a potent chemotactic growth factor, may mediate the fibrotic component of CLD. The objectives of this study were to determine if tracheal aspirate (TA concentrations of PDGF-BB increase the first 2 weeks of life in premature neonates undergoing mechanical ventilation for respiratory distress syndrome (RDS, its relationship to the development of CLD, pulmonary hemorrhage (PH and its relationship to airway colonization with Ureaplasma urealyticum (Uu. Methods Infants with a birth weight less than 1500 grams who required mechanical ventilation for RDS were enrolled into this study with parental consent. Tracheal aspirates were collected daily during clinically indicated suctioning. Uu cultures were performed on TA collected in the first week of life. TA supernatants were assayed for PDGF-BB and secretory component of IgA concentrations using ELISA techniques. Results Fifty premature neonates were enrolled into the study. Twenty-eight infants were oxygen dependent at 28 days of life and 16 infants were oxygen dependent at 36 weeks postconceptual age. PDGF-BB concentrations peaked between 4 and 6 days of life. Maximum PDGF-BB concentrations were significantly higher in infants who developed CLD or died from respiratory failure. PH was associated with increased risk of CLD and was associated with higher PDGF-BB concentrations. There was no correlation between maximum PDGF-BB concentrations and Uu isolation from the airway. Conclusions PDGF-BB concentrations increase in TAs of infants who undergo mechanical ventilation for RDS during the first 2 weeks of life and maximal concentrations are greater in those infants who subsequently develop CLD. Elevation in lung PDGF-BB may play a role in the development of CLD.

  14. Platelet-derived growth factor regulates vascular smooth muscle phenotype via mammalian target of rapamycin complex 1

    International Nuclear Information System (INIS)

    Ha, Jung Min; Yun, Sung Ji; Kim, Young Whan; Jin, Seo Yeon; Lee, Hye Sun; Song, Sang Heon; Shin, Hwa Kyoung; Bae, Sun Sik

    2015-01-01

    Mammalian target of rapamycin complex (mTORC) regulates various cellular processes including proliferation, growth, migration and differentiation. In this study, we showed that mTORC1 regulates platelet-derived growth factor (PDGF)-induced phenotypic conversion of vascular smooth muscle cells (VSMCs). Stimulation of contractile VSMCs with PDGF significantly reduced the expression of contractile marker proteins in a time- and dose-dependent manner. In addition, angiotensin II (AngII)-induced contraction of VSMCs was completely blocked by the stimulation of VSMCs with PDGF. PDGF-dependent suppression of VSMC marker gene expression was significantly blocked by inhibition of phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and mTOR whereas inhibition of p38 MAPK had no effect. In particular, inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked the PDGF-dependent phenotypic change of VSMCs whereas silencing of Rictor had no effect. In addition, loss of AngII-dependent contraction by PDGF was significantly retained by silencing of Raptor. Inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked PDGF-induced proliferation of VSMCs. Taken together, we suggest that mTORC1 plays an essential role in PDGF-dependent phenotypic changes of VSMCs. - Graphical abstract: Regulation of VSMC phenotype by PDGF-dependent activation of mTORC1. - Highlights: • The expression of contractile marker proteins was reduced by PDGF stimulation. • PDGF-dependent phenotypic conversion of VSMCs was blocked by inhibition of mTOR. • PDGF-induced proliferation of VSMCs was attenuated by inhibition of mTORC1. • mTORC1 plays a critical role in PDGF-dependent phenotypic conversion of VSMCs

  15. Platelet-derived growth factor regulates vascular smooth muscle phenotype via mammalian target of rapamycin complex 1

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jung Min; Yun, Sung Ji; Kim, Young Whan; Jin, Seo Yeon; Lee, Hye Sun [Medical Research Institute, Department of Pharmacology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Song, Sang Heon [Department of Internal Medicine, Pusan National University Hospital, Busan (Korea, Republic of); Shin, Hwa Kyoung [Department of Anatomy, Pusan National University School of Korean Medicine, Yangsan (Korea, Republic of); Bae, Sun Sik, E-mail: sunsik@pusan.ac.kr [Medical Research Institute, Department of Pharmacology, Pusan National University School of Medicine, Yangsan (Korea, Republic of)

    2015-08-14

    Mammalian target of rapamycin complex (mTORC) regulates various cellular processes including proliferation, growth, migration and differentiation. In this study, we showed that mTORC1 regulates platelet-derived growth factor (PDGF)-induced phenotypic conversion of vascular smooth muscle cells (VSMCs). Stimulation of contractile VSMCs with PDGF significantly reduced the expression of contractile marker proteins in a time- and dose-dependent manner. In addition, angiotensin II (AngII)-induced contraction of VSMCs was completely blocked by the stimulation of VSMCs with PDGF. PDGF-dependent suppression of VSMC marker gene expression was significantly blocked by inhibition of phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and mTOR whereas inhibition of p38 MAPK had no effect. In particular, inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked the PDGF-dependent phenotypic change of VSMCs whereas silencing of Rictor had no effect. In addition, loss of AngII-dependent contraction by PDGF was significantly retained by silencing of Raptor. Inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked PDGF-induced proliferation of VSMCs. Taken together, we suggest that mTORC1 plays an essential role in PDGF-dependent phenotypic changes of VSMCs. - Graphical abstract: Regulation of VSMC phenotype by PDGF-dependent activation of mTORC1. - Highlights: • The expression of contractile marker proteins was reduced by PDGF stimulation. • PDGF-dependent phenotypic conversion of VSMCs was blocked by inhibition of mTOR. • PDGF-induced proliferation of VSMCs was attenuated by inhibition of mTORC1. • mTORC1 plays a critical role in PDGF-dependent phenotypic conversion of VSMCs.

  16. Platelet-derived growth factor (PDGF) stimulates glycogen synthase activity in 3T3 cells

    International Nuclear Information System (INIS)

    Chan, C.P.; Bowen-Pope, D.F.; Ross, R.; Krebs, E.G.

    1986-01-01

    Hormonal regulation of glycogen synthase, an enzyme that can be phosphorylated on multiple sites, is often associated with changes in its phosphorylation state. Enzyme activation is conventionally monitored by determining the synthase activity ratio [(activity in the absence of glucose 6-P)/(activity in the presence of glucose 6-P)]. Insulin causes an activation of glycogen synthase with a concomitant decrease in its phosphate content. In a previous report, the authors showed that epidermal growth factor (EGF) increases the glycogen synthase activity ratio in Swiss 3T3 cells. The time and dose-dependency of this response was similar to that of insulin. Their recent results indicate that PDGF also stimulates glycogen synthase activity. Enzyme activation was maximal after 30 min. of incubation with PDGF; the time course observed was very similar to that with insulin and EGF. At 1 ng/ml (0.03nM), PDGF caused a maximal stimulation of 4-fold in synthase activity ratio. Half-maximal stimulation was observed at 0.2 ng/ml (6 pM). The time course of changes in enzyme activity ratio closely followed that of 125 I-PDGF binding. The authors data suggest that PDGF, as well as EFG and insulin, may be important in regulating glycogen synthesis through phosphorylation/dephosphorylation mechanisms

  17. Treatment of AVN Using Autologous BM Stem Cells and Activated Platelet-Derived Growth Factor Concentrates.

    Science.gov (United States)

    Nandeesh, Nagaraj H; Janardhan, Kiranmayee; Subramanian, Vignesh; Ashtekar, Abhishek Bhushan; Srikruthi, Nandagiri; Koka, Prasad S; Deb, Kaushik

    Avascular Necrosis (AVN) of hip is a devastating condition seen in younger individuals. It is the ischemic death of the constituents of the bone cartilage of the hip. The femoral head (FH) is the most common site for AVN. It results from interruption of the normal blood flow to the FH that fits into the hip socket. Earlier studies using autologous bone marrow stem cell concentrate injections have shown encouraging results with average success rates. The current study was designed to improve significantly the cartilage regeneration and clinical outcome. Total of 48 patients underwent autologous bone marrow stem cell and activated platelet-rich plasma derived growth factor concentrate (PRP-GFC) therapy for early and advanced stages AVN of femoral head in a single multi-specialty center. The total treatment was divided into three phases. In the phase I, all the clinical diagnostic measurements such as magnetic resonance imaging (MRI), computed tomography (CT) etc. with respect to the AVN patients and bone marrow aspiration from posterior iliac spine from the patients were carried out. In the phase II, isolation of stem cells and preparation from the patients were performed. Subsequently, in phase III, the stem cells and PRP- GFCs were transplanted in the enrolled patients. Ninety three percent of the enrolled AVN patients showed marked enhancement in the hip bone joint space (more than 3mm) after combined stem cells and PRP-GFC treatment as evidenced by comparison of the pre- and post-treatment MRI data thus indicative of regeneration of cartilage. The treated patients showed significant improvement in their motor function, cartilage regrowth (3 to 10mm), and high satisfaction in the two-year follow-up. Combination of stem cell and PRP-GFC therapy has shown promising cartilage regeneration in 45 out of 48 patients of AVN. This study clearly demonstrates the safety and efficacy of this treatment. Larger numbers of patients need to be evaluated to better understand the

  18. Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

    Science.gov (United States)

    Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

    1994-05-13

    Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

  19. Expression of platelet-derived growth factor BB, erythropoietin and erythropoietin receptor in canine and feline osteosarcoma.

    Science.gov (United States)

    Meyer, F R L; Steinborn, R; Grausgruber, H; Wolfesberger, B; Walter, I

    2015-10-01

    The discovery of expression of the erythropoietin receptor (EPO-R) on neoplastic cells has led to concerns about the safety of treating anaemic cancer patients with EPO. In addition to its endocrine function, the receptor may play a role in tumour progression through an autocrine mechanism. In this study, the expression of EPO, EPO-R and platelet-derived growth factor BB (PDGF-BB) was analysed in five feline and 13 canine osteosarcomas using immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). EPO expression was positive in all tumours by IHC, but EPO mRNA was only detected in 38% of the canine and 40% of the feline samples. EPO-R was expressed in all samples by quantitative RT-PCR (RT-qPCR) and IHC. EPO-R mRNA was expressed at higher levels in all feline tumours, tumour cell lines, and kidney when compared to canine tissues. PDGF-BB expression was variable by IHC, but mRNA was detected in all samples. To assess the functionality of the EPO-R on tumour cells, the proliferation of canine and feline osteosarcoma cell lines was evaluated after EPO administration using an alamarBlue assay and Ki67 immunostaining. All primary cell lines responded to EPO treatment in at least one of the performed assays, but the effect on proliferation was very low indicating only a weak responsiveness of EPO-R. In conclusion, since EPO and its receptor are expressed by canine and feline osteosarcomas, an autocrine or paracrine tumour progression mechanism cannot be excluded, although in vitro data suggest a minimal role of EPO-R in osteosarcoma cell proliferation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Assessment of platelet-derived growth factor using A splinted full thickness dermal wound model in bearded dragons (Pogona vitticeps).

    Science.gov (United States)

    Keller, Krista A; Paul-Murphy, Joanne; Weber, E P Scott; Kass, Philip H; Guzman, Sanchez-Migallon David; Park, Shin Ae; Raghunathan, Vijay Krishna; Gustavsen, Kate A; Murphy, Christopher J

    2014-12-01

    Wounds in reptiles are a common reason for presentation to a veterinarian. At this time there is limited information on effective topical medications to aid in wound closure. The objectives of this study were to translate the splinted, full-thickness dermal wound model, validated in mice, to the bearded dragon (Pogona vitticeps) and to determine the effect of topical becaplermin (BP), a platelet-derived growth factor (0.01%), on the rate of wound closure. Ten bearded dragons were anesthetized and two full-thickness cutaneous wounds were made on the dorsum of each lizard. Encircling splints were applied surrounding each wound and subsequently covered by a semi-occlusive dressing. Five lizards had one wound treated with BP and the adjacent wound treated with a vehicle control. Five additional lizards had one wound treated with saline and the second wound treated with a vehicle control. Wounds were imaged daily, and the wound area was measured using digital image analysis. The change in percentage wound closure over 17 days and the time to 50% wound closure was compared among the four treatment groups. There was no significant difference in wound closure rates between BP-treated and saline-treated wounds or in the time to 50% wound closure between any treatments. Vehicle-treated wounds adjacent to saline-treated wounds closed significantly slower than did BP (P dragons. When compared with saline, BP did not have a significant effect on wound closure rates, while the vehicle alone delayed wound closure. Histologic analysis of experimentally created wounds throughout the wound healing process is needed to further evaluate the effects of these treatments on reptile dermal wound healing.

  1. Platelet-derived growth factor receptor beta: a novel urinary biomarker for recurrence of non-muscle-invasive bladder cancer.

    Science.gov (United States)

    Feng, Jiayu; He, Weifeng; Song, Yajun; Wang, Ying; Simpson, Richard J; Zhang, Xiaorong; Luo, Gaoxing; Wu, Jun; Huang, Chibing

    2014-01-01

    Non-muscle-invasive bladder cancer (NMIBC) is one of the most common malignant tumors in the urological system with a high risk of recurrence, and effective non-invasive biomarkers for NMIBC relapse are still needed. The human urinary proteome can reflect the status of the microenvironment of the urinary system and is an ideal source for clinical diagnosis of urinary system diseases. Our previous work used proteomics to identify 1643 high-confidence urinary proteins in the urine from a healthy population. Here, we used bioinformatics to construct a cancer-associated protein-protein interaction (PPI) network comprising 16 high-abundance urinary proteins based on the urinary proteome database. As a result, platelet-derived growth factor receptor beta (PDGFRB) was selected for further validation as a candidate biomarker for NMIBC diagnosis and prognosis. Although the levels of urinary PDGFRB showed no significant difference between patients pre- and post-surgery (n = 185, P>0.05), over 3 years of follow-up, urinary PDGFRB was shown to be significantly higher in relapsed patients (n = 68) than in relapse-free patients (n = 117, P<0.001). The levels of urinary PDGFRB were significantly correlated with the risk of 3-year recurrence of NMIBC, and these levels improved the accuracy of a NMIBC recurrence risk prediction model that included age, tumor size, and tumor number (area under the curve, 0.862; 95% CI, 0.809 to 0.914) compared to PDGFR alone. Therefore, we surmise that urinary PDGFRB could serve as a non-invasive biomarker for predicting NMIBC recurrence.

  2. Platelet-derived growth factor (PDGF)-C inhibits neuroretinal apoptosis in a murine model of focal retinal degeneration.

    Science.gov (United States)

    Wang, Yujuan; Abu-Asab, Mones S; Yu, Cheng-Rong; Tang, Zhongshu; Shen, Defen; Tuo, Jingsheng; Li, Xuri; Chan, Chi-Chao

    2014-06-01

    Platelet-derived growth factor (PDGF)-C is a member of the PDGF family and is critical for neuronal survival in the central nervous system. We studied the possible survival and antiapoptotic effects of PDGF-C on focal retinal lesions in Ccl2(-/-)/Cx3cr1(-/-) on C57BL/6N [Crb1(rd8)] (DKO rd8) background mice, a model for progressive and focal retinal degeneration. We found no difference in transcript and protein expression of PDGF-C in the retina between DKO rd8 mice and wild type (WT, C57BL/6N). Recombinant PDGF-CC protein (500 ng/eye) was injected intravitreally into the right eye of DKO rd8 mice with phosphate-buffered saline as controls into the left eye. The retinal effects of PDGF-C were assessed by fundoscopy, ocular histopathology, A2E levels, apoptotic molecule analysis, and direct flat mount retinal vascular labeling. We found that the PDGF-CC-treated eyes showed slower progression or attenuation of the focal retinal lesions, lesser photoreceptor and retinal pigment epithelial degeneration resulting in better-preserved photoreceptor structure. Lower expression of apoptotic molecules was detected in the PDGF-CC-treated eyes than in controls. In addition, no retinal neovascularization was observed after PDGF-CC treatment. Our results demonstrate that PDGF-C potently ameliorates photoreceptor degeneration via the suppression of apoptotic pathways without inducing retinal angiogenesis. The protective effects of PDGF-C suggest a novel alternative approach for potential age-related retinal degeneration treatment.

  3. Bone Morphogenic Protein 4-Smad-Induced Upregulation of Platelet-Derived Growth Factor AA Impairs Endothelial Function.

    Science.gov (United States)

    Hu, Weining; Zhang, Yang; Wang, Li; Lau, Chi Wai; Xu, Jian; Luo, Jiang-Yun; Gou, Lingshan; Yao, Xiaoqiang; Chen, Zhen-Yu; Ma, Ronald Ching Wan; Tian, Xiao Yu; Huang, Yu

    2016-03-01

    Bone morphogenic protein 4 (BMP4) is an important mediator of endothelial dysfunction in cardio-metabolic diseases, whereas platelet-derived growth factors (PDGFs) are major angiogenic and proinflammatory mediator, although the functional link between these 2 factors is unknown. The present study investigated whether PDGF mediates BMP4-induced endothelial dysfunction in diabetes mellitus. We generated Ad-Bmp4 to overexpress Bmp4 and Ad-Pdgfa-shRNA to knockdown Pdgfa in mice through tail intravenous injection. SMAD4-shRNA lentivirus, SMAD1-shRNA, and SMAD5 shRNA adenovirus were used for knockdown in human and mouse endothelial cells. We found that PDGF-AA impaired endothelium-dependent vasodilation in aortas and mesenteric resistance arteries. BMP4 upregulated PDGF-AA in human and mouse endothelial cells, which was abolished by BMP4 antagonist noggin or knockdown of SMAD1/5 or SMAD4. BMP4-impared relaxation in mouse aorta was also ameliorated by PDGF-AA neutralizing antibody. Tail injection of Ad-Pdgfa-shRNA ameliorates endothelial dysfunction induced by Bmp4 overexpression (Ad-Bmp4) in vivo. Serum PDGF-AA was elevated in both diabetic patients and diabetic db/db mice compared with nondiabetic controls. Pdgfa-shRNA or Bmp4-shRNA adenovirus reduced serum PDGF-AA concentration in db/db mice. PDGF-AA neutralizing antibody or tail injection with Pdgfa-shRNA adenovirus improved endothelial function in aortas and mesenteric resistance arteries from db/db mice. The effect of PDGF-AA on endothelial function in mouse aorta was also inhibited by Ad-Pdgfra-shRNA to inhibit PDGFRα. The present study provides novel evidences to show that PDGF-AA impairs endothelium-dependent vasodilation and PDGF-AA mediates BMP4-induced adverse effect on endothelial cell function through SMAD1/5- and SMAD4-dependent mechanisms. Inhibition of PGDF-AA ameliorates vascular dysfunction in diabetic mice. © 2016 American Heart Association, Inc.

  4. An aptamer-based biosensing platform for highly sensitive detection of platelet-derived growth factor via enzyme-mediated direct electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Deng Kun; Xiang Yang; Zhang Liqun; Chen Qinghai [Laboratory of the Clinical Experimental Base of Biosensor and Microarray, Center of Molecule and Gene Diagnosis, Southwest Hospital, Third Military Medical University, Chongqing 400042 (China); Fu Weiling, E-mail: weilingfu@yahoo.com [Laboratory of the Clinical Experimental Base of Biosensor and Microarray, Center of Molecule and Gene Diagnosis, Southwest Hospital, Third Military Medical University, Chongqing 400042 (China)

    2013-01-08

    Highlights: Black-Right-Pointing-Pointer Direct electrochemistry of glucose oxidase used for signal generation in aptasensor. Black-Right-Pointing-Pointer Using novel nanocomposite for immobilization and signal amplification. Black-Right-Pointing-Pointer Sensitive electrochemical detection of platelet-derived growth factor. - Abstract: In this work, a new label-free electrochemical aptamer-based sensor (aptasensor) was constructed for detection of platelet-derived growth factor (PDGF) based on the direct electrochemistry of glucose oxidase (GOD). For this proposed aptasensor, poly(diallyldimethylammonium chloride) (PDDA)-protected graphene-gold nanoparticles (P-Gra-GNPs) composite was firstly coated on electrode surface to form the interface with biocompatibility and huge surface area for the adsorption of GOD layer. Subsequently, gold nanoclusters (GNCs) were deposited on the surface of GOD to capture PDGF binding aptamer (PBA). Finally, GOD as a blocking reagent was employed to block the remaining active sites of the GNCs and avoid the nonspecific adsorption. With the direct electron transfer of double layer GOD membranes, the aptasensor showed excellent electrochemical response and the peak current decreased linearly with increasing logarithm of PDGF concentration from 0.005 nM to 60 nM with a relatively low limit of detection of 1.7 pM. The proposed aptasensor exhibited high specificity, good reproducibility and long-term stability, which provided a new promising technique for aptamer-based protein detection.

  5. An aptamer-based biosensing platform for highly sensitive detection of platelet-derived growth factor via enzyme-mediated direct electrochemistry

    International Nuclear Information System (INIS)

    Deng Kun; Xiang Yang; Zhang Liqun; Chen Qinghai; Fu Weiling

    2013-01-01

    Highlights: ► Direct electrochemistry of glucose oxidase used for signal generation in aptasensor. ► Using novel nanocomposite for immobilization and signal amplification. ► Sensitive electrochemical detection of platelet-derived growth factor. - Abstract: In this work, a new label-free electrochemical aptamer-based sensor (aptasensor) was constructed for detection of platelet-derived growth factor (PDGF) based on the direct electrochemistry of glucose oxidase (GOD). For this proposed aptasensor, poly(diallyldimethylammonium chloride) (PDDA)-protected graphene-gold nanoparticles (P-Gra-GNPs) composite was firstly coated on electrode surface to form the interface with biocompatibility and huge surface area for the adsorption of GOD layer. Subsequently, gold nanoclusters (GNCs) were deposited on the surface of GOD to capture PDGF binding aptamer (PBA). Finally, GOD as a blocking reagent was employed to block the remaining active sites of the GNCs and avoid the nonspecific adsorption. With the direct electron transfer of double layer GOD membranes, the aptasensor showed excellent electrochemical response and the peak current decreased linearly with increasing logarithm of PDGF concentration from 0.005 nM to 60 nM with a relatively low limit of detection of 1.7 pM. The proposed aptasensor exhibited high specificity, good reproducibility and long-term stability, which provided a new promising technique for aptamer-based protein detection.

  6. Quantification of platelets and platelet derived growth factors from platelet-rich-plasma (PRP) prepared at different centrifugal force (g) and time.

    Science.gov (United States)

    Arora, Satyam; Doda, Veena; Kotwal, Urvershi; Dogra, Mitu

    2016-02-01

    Platelet derived biomaterials represent a key source of cytokines and growth factors extensively used for tissue regeneration; wound healing and tissue repair. Our study was to quantify platelets and growth factors released by PRP when prepared at different centrifugal force (g) and time. Our study was approved by the institutional ethical committee. One hundred millilitres of whole blood (WB) was collected in bag with CPDA as the anticoagulant(AC); (14 mL for 100 mL WB ratio). Nine aliquots of 10 mL each were made from the bag and set of three aliquots were made a group. PRP was prepared at varying centrifugal force (group A: -110 g, group B: -208 g & group C: -440 g) & time (1: -5 min, 2: -10 min & 3: -20 min). Contents of each PRP prepared were analysed. Commercial sandwich ELISA kits were used to quantify the concentrations of CD62P (Diaclone SAS; France), Platelet derived growth factors-AB (Qayee-Bio; China), transforming growth factor-β1 (DRG; Germany) and vascular endothelial growth factor (Boster Immuno Leader; USA) released in each PRP prepared. Eight volunteers were enrolled in the study (24-30 years). The baseline blood counts of all the volunteers were comparable (p ≥ 0.05). Mean ± SD of platelet yield of all nine groups ranged from 17.2 ± 4.2% to 78.7 ± 5.7%. Each PRP was activated with calcified thromboplastin to quantify the growth factors released by them. Significantly higher (p < 0.05) transforming growth factor-β1 and vascular endothelial growth factor were released compared to the baseline. Our study highlights the variation in both force (g) and time results in changes at cellular level and growth factor concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Release kinetics of platelet-derived and plasma-derived growth factors from autologous plasma rich in growth factors.

    Science.gov (United States)

    Anitua, Eduardo; Zalduendo, Mari Mar; Alkhraisat, Mohammad Hamdan; Orive, Gorka

    2013-10-01

    Many studies have evaluated the biological effects of platelet rich plasma reporting the final outcomes on cell and tissues. However, few studies have dealt with the kinetics of growth factor delivery by plasma rich in growth factors. Venous blood was obtained from three healthy volunteers and processed with PRGF-Endoret technology to prepare autologous plasma rich in growth factors. The gel-like fibrin scaffolds were then incubated in triplicate, in a cell culture medium to monitor the release of PDGF-AB, VEGF, HGF and IGF-I during 8 days of incubation. A leukocyte-platelet rich plasma was prepared employing the same technology and the concentrations of growth factors and interleukin-1β were determined after 24h of incubation. After each period, the medium was collected, fibrin clot was destroyed and the supernatants were stored at -80°C until analysis. The growth factor delivery is diffusion controlled with a rapid initial release by 30% of the bioactive content after 1h of incubation and a steady state release when almost 70% of the growth factor content has been delivered. Autologous fibrin matrix retained almost 30% of the amount of the growth factors after 8 days of incubation. The addition of leukocytes to the formula of platelet rich plasma did not increase the concentration of the growth factors, while it drastically increased the presence of pro-inflammatory IL-1β. Further studies employing an in vitro inflammatory model would be interesting to study the difference in growth factors and pro-inflammatory cytokines between leukocyte-free and leukocyte-rich platelet rich plasma. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. The influence of elevated levels of platelet-derived endothelial cell growth factor/thymidine phosphorylase on tumourigenicity, tumour growth, and oxygenation

    International Nuclear Information System (INIS)

    Griffiths, L.; Stratford, I.J.

    1998-01-01

    Purpose: Investigation of the effect of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) on various aspects of tumour growth in a xenograft model, including growth rate, tumourigenicity and oxygenation levels. Methods and Materials: MDA 231 breast cancer cells overexpressing PD-ECGF/TP protein were made by retroviral transduction. These cells were grown in vitro and in vivo as xenografts. Direct measurement of tumours was used to record growth parameters, while the comet assay with the bioreductive drug RSU 1069 was used to assess tumour cell oxygenation. Results: We report that MDA 231 breast tumour cell lines expressing an increased range of levels of PD-ECGF/TP have increased tumourigenicity positively related to the level of PD-ECGF/TP when implanted in nude mice. As previously reported, tumours grown from these overexpressing cell lines grew faster than the parental line. These tumours expressed higher levels of TP activity and showed increased immunocytochemical staining for PD-ECGF. In addition, the rate of growth was found to be positively related to the level of PD-ECGF/TP expressed by the tumour cells. When the comet assay was used to compare the oxygenation status of cells between the parental and PD-ECGF/TP overexpressing tumours, the latter were found to have a larger proportion of well oxygenated cells. This is consistent with these tumours having an increased and functionally competent vascular supply in response to the expression of PD-ECGF/TP. Conclusion: PD-ECGF/TP appears to be capable of influencing tumourigenicity, angiogenesis and tumour growth in a proportional manner and can directly influence tumour oxygenation levels via its role in formation of functional vasculature

  9. Activated platelet-derived growth factor β receptor and Ras-mitogen-activated protein kinase pathway in natural bovine urinary bladder carcinomas.

    Science.gov (United States)

    Corteggio, Annunziata; Di Geronimo, Ornella; Roperto, Sante; Roperto, Franco; Borzacchiello, Giuseppe

    2012-03-01

    Bovine papillomavirus types 1 or 2 (BPV-1/2) are involved in the aetiopathogenesis of bovine urinary bladder cancer. BPV-1/2 E5 activates the platelet-derived growth factor β receptor (PDGFβR). The aim of this study was to analyse the Ras/mitogen-activated protein kinase (MAPK) pathway in relation to activation of PDGFβR in natural bovine urinary bladder carcinomas. Co-immunoprecipitation and Western blot analysis demonstrated that recruitment of growth factor receptor bound protein 2 (GRB-2) and Sos-1 to the activated PDGFβR was increased in carcinomas compared to normal tissues. Higher grade bovine urinary bladder carcinomas were associated with activation of Ras, but not with activation of downstream mitogen-activated protein kinase/extracellular signal-regulated kinase (Mek 1/2) or extracellular signal-regulated kinase (Erk 1/2). Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Post-transcriptional regulation of osteoblastic platelet-derived growth factor receptor-alpha expression by co-cultured primary endothelial cells

    DEFF Research Database (Denmark)

    Finkenzeller, Günter; Mehlhorn, Alexander T; Schmal, Hagen

    2010-01-01

    -alpha downregulation is dependent on time and cell number. This effect was specific to endothelial cells and was not observed when hOBs were co-cultured with human primary chondrocytes or fibroblasts. Likewise, HUVEC-mediated suppression of PDGFR-alpha expression was only seen in hOBs and mesenchymal stem cells......Platelet-derived growth factor receptor (PDGFR) signaling plays an important role in osteoblast function. Inhibition of PDGFR activity leads to a suppression of osteoblast proliferation, whereas mineralized matrix production is enhanced. In previous experiments, we showed that co......-cultivation of human primary endothelial cells and human primary osteoblasts (hOBs) leads to a cell contact-dependent downregulation of PDGFR-alpha expression in the osteoblasts. In this study, we investigated this effect in more detail, revealing that human umbilical vein endothelial cell (HUVEC)-mediated PDGFR...

  11. 15-Deoxy-Δ12,14-prostaglandin J2 and thiazolidinediones transactivate epidermal growth factor and platelet-derived growth factor receptors in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Ichiki, Toshihiro; Tokunou, Tomotake; Fukuyama, Kae; Iino, Naoko; Masuda, Satoko; Takeshita, Akira

    2004-01-01

    Proliferation of vascular smooth muscle cells (VSMCs) is induced by various mitogens through activation of extracellular signal-regulated protein kinase (ERK) pathway. We recently reported that peroxisome proliferator-activated receptor (PPAR)γ activators such as 15-deoxy-Δ 12,14 -prostaglandin J2 (15-d-PGJ2) and thiazolidinediones (TZDs) activated MEK/ERK pathway through phosphatidylinositol 3-kinase (PI3-K) and induced proliferation of VSMCs. However, the precise mechanisms of PPARγ activators-induced activation of PI3-K/ERK pathway have not been determined. We examined whether transactivation of growth factor receptor is involved in this process. Stimulation of VSMCs with 15-d-PGJ2 or TZDs for 15 min induced phosphorylation of ERK1/2 and Akt. 15-d-PGJ2- or TZDs-induced phosphorylation of ERK1/2 and Akt was inhibited by AG1478, an inhibitor of epidermal growth factor receptor (EGF-R) as well as AG1295, an inhibitor of platelet derived growth factor receptor (PDGF-R). 15-d-PGJ2-induced phosphorylation of both EGF-R and PDGF-R. GM6001, a matrix metalloproteinase inhibitor, and PP2, a Src family protein kinase inhibitor, suppressed 15-d-PGJ2- and TZDs-induced phosphorylation of EGF-R and PDGFβ-R as well as activation of ERK1/2 and Akt. PDGFβ-R was co-immunoprecipitated with EGF-R, regardless of the presence or absence of 15-d-PGJ2. These data suggest that 15-d-PGJ2 and TZDs activate PI3-K/ERK pathway through Src family kinase- and matrix metalloproteinase-dependent transactivation of EGF-R and PDGF-R. Both receptors seemed to associate constitutively. This novel signaling mechanisms may contribute to diverse biological functions of PPARγ activators

  12. Transforming growth factor β inhibits platelet derived growth factor-induced vascular smooth muscle cell proliferation via Akt-independent, Smad-mediated cyclin D1 downregulation.

    Directory of Open Access Journals (Sweden)

    Abel Martin-Garrido

    Full Text Available In adult tissue, vascular smooth muscle cells (VSMCs exist in a differentiated phenotype, which is defined by the expression of contractile proteins and lack of proliferation. After vascular injury, VSMC adopt a synthetic phenotype associated with proliferation, migration and matrix secretion. The transition between phenotypes is a consequence of the extracellular environment, and in particular, is regulated by agonists such as the pro-differentiating cytokine transforming growth factor β (TGFβ and the pro-proliferative cytokine platelet derived growth factor (PDGF. In this study, we investigated the interplay between TGFβ and PDGF with respect to their ability to regulate VSMC proliferation. Stimulation of human aortic VSMC with TGFβ completely blocked proliferation induced by all isoforms of PDGF, as measured by DNA synthesis and total cell number. Mechanistically, PDGF-induced Cyclin D1 mRNA and protein expression was inhibited by TGFβ. TGFβ had no effect on PDGF activation of its receptor and ERK1/2, but inhibited Akt activation. However, constitutively active Akt did not reverse the inhibitory effect of TGFβ on Cyclin D1 expression even though inhibition of the proteasome blocked the effect of TGFβ. siRNA against Smad4 completely reversed the inhibitory effect of TGFβ on PDGF-induced Cyclin D1 expression and restored proliferation in response to PDGF. Moreover, siRNA against KLF5 prevented Cyclin D1 upregulation by PDGF and overexpression of KLF5 partially reversed TGFβ-induced inhibition of Cyclin D1 expression. Taken together, our results demonstrate that KLF5 is required for PDGF-induced Cyclin D1 expression, which is inhibited by TGFβ via a Smad dependent mechanism, resulting in arrest of VSMCs in the G1 phase of the cell cycle.

  13. Transforming growth factor β inhibits platelet derived growth factor-induced vascular smooth muscle cell proliferation via Akt-independent, Smad-mediated cyclin D1 downregulation.

    Science.gov (United States)

    Martin-Garrido, Abel; Williams, Holly C; Lee, Minyoung; Seidel-Rogol, Bonnie; Ci, Xinpei; Dong, Jin-Tang; Lassègue, Bernard; Martín, Alejandra San; Griendling, Kathy K

    2013-01-01

    In adult tissue, vascular smooth muscle cells (VSMCs) exist in a differentiated phenotype, which is defined by the expression of contractile proteins and lack of proliferation. After vascular injury, VSMC adopt a synthetic phenotype associated with proliferation, migration and matrix secretion. The transition between phenotypes is a consequence of the extracellular environment, and in particular, is regulated by agonists such as the pro-differentiating cytokine transforming growth factor β (TGFβ) and the pro-proliferative cytokine platelet derived growth factor (PDGF). In this study, we investigated the interplay between TGFβ and PDGF with respect to their ability to regulate VSMC proliferation. Stimulation of human aortic VSMC with TGFβ completely blocked proliferation induced by all isoforms of PDGF, as measured by DNA synthesis and total cell number. Mechanistically, PDGF-induced Cyclin D1 mRNA and protein expression was inhibited by TGFβ. TGFβ had no effect on PDGF activation of its receptor and ERK1/2, but inhibited Akt activation. However, constitutively active Akt did not reverse the inhibitory effect of TGFβ on Cyclin D1 expression even though inhibition of the proteasome blocked the effect of TGFβ. siRNA against Smad4 completely reversed the inhibitory effect of TGFβ on PDGF-induced Cyclin D1 expression and restored proliferation in response to PDGF. Moreover, siRNA against KLF5 prevented Cyclin D1 upregulation by PDGF and overexpression of KLF5 partially reversed TGFβ-induced inhibition of Cyclin D1 expression. Taken together, our results demonstrate that KLF5 is required for PDGF-induced Cyclin D1 expression, which is inhibited by TGFβ via a Smad dependent mechanism, resulting in arrest of VSMCs in the G1 phase of the cell cycle.

  14. Growth/differentiation factor-5 significantly enhances periodontal wound healing/regeneration compared with platelet-derived growth factor-BB in dogs.

    Science.gov (United States)

    Kwon, Hyuk-Rak; Wikesjö, Ulf M E; Park, Jung-Chul; Kim, Young-Taek; Bastone, Patrizia; Pippig, Susanne D; Kim, Chong-Kwan

    2010-08-01

    Recombinant human growth/differentiation factor-5 (rhGDF-5) in a particulate beta-tricalcium phosphate (beta-TCP) carrier is being evaluated to support periodontal regeneration. The objective of this study was to evaluate periodontal wound healing/regeneration following an established clinical (benchmark) protocol including surgical implantation of rhGDF-5/beta-TCP in comparison with that following implantation of recombinant human platelet-derived growth factor-BB (rhPDGF) combined with a particulate beta-TCP biomaterial using an established canine defect model. Bilateral, 4 x 5 mm (width x depth), one-wall, critical-size, intrabony periodontal defects were surgically created at the mandibular second and fourth pre-molar teeth in five adult Beagle dogs. Defect sites were randomized to receive rhGDF-5/beta-TCP or the rhPDGF construct followed by wound closure for primary intention healing. The animals were sacrificed following an 8-week healing interval for histological and histometric examination. Clinical healing was generally uneventful. Sites receiving rhGDF-5/beta-TCP exhibited a significantly enhanced cementum formation compared with sites receiving the rhPDGF construct, averaging (+/-SD) 4.49+/-0.48 versus 2.72+/-0.91 mm (palveolar bone. Both protocols displayed beta-TCP residues apparently undergoing resorption. Application of both materials appears safe, as they were associated with limited, if any, adverse events. rhGDF-5/beta-TCP shows a significant potential to support/accelerate periodontal wound healing/regeneration. Application of rhGDF-5/beta-TCP appears safe and should be further evaluated in human clinical trials.

  15. The Effects of Imatinib Mesylate on Cellular Viability, Platelet Derived Growth Factor and Stem Cell Factor in Mouse Testicular Normal Leydig Cells.

    Science.gov (United States)

    Kheradmand, Fatemeh; Hashemnia, Seyyed Mohammad Reza; Valizadeh, Nasim; Roshan-Milani, Shiva

    2016-01-01

    Growth factors play an essential role in the development of tumor and normal cells like testicular leydig cells. Treatment of cancer with anti-cancer agents like imatinib mesylate may interfere with normal leydig cell activity, growth and fertility through failure in growth factors' production or their signaling pathways. The purpose of the study was to determine cellular viability and the levels of, platelet derived growth factor (PDGF) and stem cell factor (SCF) in normal mouse leydig cells exposed to imatinib, and addressing the effect of imatinib on fertility potential. The mouse TM3 leydig cells were treated with 0 (control), 2.5, 5, 10 and 20 μM imatinib for 2, 4 and 6 days. Each experiment was repeated three times (15 experiments in each day).The cellular viability and growth factors levels were assessed by MTT and ELISA methods, respectively. For statistical analysis, one-way ANOVA with Tukey's post hoc and Kruskal-Wallis test were performed. A p-value less than 0.05 was considered statistically significant. With increasing drug concentration, cellular viability decreased significantly (pcellular viability, PDGF and SCF levels. Imatinib may reduce fertility potential especially at higher concentrations in patients treated with this drug by decreasing cellular viability. The effect of imatinib on leydig cells is associated with PDGF stimulation. Of course future studies can be helpful in exploring the long term effects of this drug.

  16. Chitosan inhibits platelet-mediated clot retraction, increases platelet-derived growth factor release, and increases residence time and bioactivity of platelet-rich plasma in vivo.

    Science.gov (United States)

    Deprés-Tremblay, Gabrielle; Chevrier, Anik; Tran-Khanh, Nicolas; Nelea, Monica; Buschmann, Michael D

    2017-11-10

    Platelet-rich plasma (PRP) has been used to treat different orthopedic conditions, however, the clinical benefits of using PRP remain uncertain. Chitosan (CS)-PRP implants have been shown to improve meniscus, rotator cuff and cartilage repair in pre-clinical models. The purpose of this current study was to investigate in vitro and in vivo mechanisms of action of CS-PRP implants. Freeze-dried formulations containing 1% (w/v) CS (80% degree of deacetylation and number average molar mass 38 kDa), 1% (w/v) trehalose as a lyoprotectant and 42.2 mM calcium chloride as a clot activator were solubilized in PRP. Gravimetric measurements and molecular/cellular imaging studies revealed that clot retraction is inhibited in CS-PRP hybrid clots through physical coating of platelets, blood cells and fibrin strands by chitosan, which interferes with platelet aggregation and platelet-mediated clot retraction. Flow cytometry and ELISA assays revealed that platelets are activated and granules secreted in CS-PRP hybrid clots and that cumulative release of platelet-derived growth factor (PDGF-AB) and epidermal growth factor is higher from CS-PRP hybrid clots compared to PRP clots in vitro. Finally, CS-PRP implants resided for up to 6 weeks in a subcutaneous implantation model and induced cell recruitment and granulation tissue synthesis, confirming greater residency and bioactivity compared to PRP in vivo.

  17. Tyrosine phosphorylation of platelet derived growth factor β receptors in coronary artery lesions: implications for vascular remodelling after directional coronary atherectomy and unstable angina pectoris

    Science.gov (United States)

    Abe, J; Deguchi, J; Takuwa, Y; Hara, K; Ikari, Y; Tamura, T; Ohno, M; Kurokawa, K

    1998-01-01

    Background—Growth factors such as platelet derived growth factor (PDGF) have been postulated to be important mediators of neointimal proliferation observed in atherosclerotic plaques and restenotic lesions following coronary interventions. Binding of PDGF to its receptor results in intrinsic receptor tyrosine kinase activation and subsequent cellular migration, proliferation, and vascular contraction.
Aims—To investigate whether the concentration of PDGF β receptor tyrosine phosphorylation obtained from directional coronary atherectomy (DCA) samples correlate with atherosclerotic plaque burden, the ability of diseased vessels to remodel, coronary risk factors, and clinical events.
Methods—DCA samples from 59 patients and 15 non-atherosclerotic left internal thoracic arteries (LITA) were analysed for PDGF β receptor tyrosine phosphorylation content by receptor immunoprecipitation and antiphosphotyrosine western blot. The amount of PDGF β receptor phosphorylation was analysed in relation to angiographic follow up data and clinical variables.
Results—PDGF β receptor tyrosine phosphorylation in the 59 DCA samples was greater than in the 15 non-atherosclerotic LITA (mean (SD) 0.84 (0.67) v 0.17 (0.08) over a control standard, p atherectomy;  restenosis PMID:9616351

  18. Local administration of platelet-derived growth factor B (PDGFB) improves follicular development and ovarian angiogenesis in a rat model of Polycystic Ovary Syndrome.

    Science.gov (United States)

    Di Pietro, Mariana; Scotti, Leopoldina; Irusta, Griselda; Tesone, Marta; Parborell, Fernanda; Abramovich, Dalhia

    2016-09-15

    Alterations in ovarian angiogenesis are common features in Polycystic Ovary Syndrome (PCOS) patients; the most studied of these alterations is the increase in vascular endothelial growth factor (VEGF) production by ovarian cells. Platelet-derived growth factor B (PDGFB) and D (PDGFD) are decreased in follicular fluid of PCOS patients and in the ovaries of a rat model of PCOS. In the present study, we aimed to analyze the effects of local administration of PDGFB on ovarian angiogenesis, follicular development and ovulation in a DHEA-induced PCOS rat model. Ovarian PDGFB administration to PCOS rats partially restored follicular development, decreased the percentage of cysts, increased the percentage of corpora lutea, and decreased the production of anti-Müllerian hormone. In addition, PDGFB administration improved ovarian angiogenesis by reversing the increase in periendothelial cell area and restoring VEGF levels. Our results shed light into the mechanisms that lead to altered ovarian function in PCOS and provide new data for potential therapeutic strategies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. cDNA cloning and expression of a human platelet-derived growth factor (PDGF) receptor specific for B-chain-containing PDGF molecules

    International Nuclear Information System (INIS)

    Claesson-Welsh, L.; Eriksson, A.; Moren, A.; Severinsson, L.; Ek, B.; Ostman, A.; Betsholtz, C.; Heldin, C.H.

    1988-01-01

    The structure of the human receptor for platelet-derived growth factor (PDGF) has been deduced through cDNA cloning. A 5.45-kilobase-pair cDNA clone predicts a 1,106-amino-acid polypeptide, including the cleavable signal sequence. The overall amino acid sequence similarity with the murine PDGFR receptor is 85%. After transcription of the cDNA and translation in vitro, a PDGR receptor antiserum was used to immunoprecipitate a product of predicted size, which also could be phosphorylated in vitro. Stable introduction of the cDNA into Chinese hamster ovary (CHO) cells led to the expression of a 190-kilodalton component, which was immunoprecipitated by the PDGF receptor antiserum; this most probably represents the mature PDGF receptor. Binding assays with different /sup 125/I-labeled dimeric forms of PDGF A and B chains showed that the PDGFR receptor expressed in CHO cells bound PDGF-BB and, to a lesser extent, PDGF-AB, but not PDGF-AA

  20. Cloning and expression of a cDNA coding for the human platelet-derived growth factor receptor: Evidence for more than one receptor class

    International Nuclear Information System (INIS)

    Gronwald, R.G.K.; Grant, F.J.; Haldeman, B.A.; Hart, C.E.; O'Hara, P.J.; Hagen, F.S.; Ross, R.; Bowen-Pope, D.F.; Murray, M.J.

    1988-01-01

    The complete nucleotide sequence of a cDNA encoding the human platelet-derived growth factor (PDGF) receptor is presented. The cDNA contains an open reading frame that codes for a protein of 1106 amino acids. Comparison to the mouse PDGF receptor reveals an overall amino acid sequence identity of 86%. This sequence identity rises to 98% in the cytoplasmic split tyrosine kinase domain. RNA blot hybridization analysis of poly(A) + RNA from human dermal fibroblasts detects a major and a minor transcript using the cDNA as a probe. Baby hamster kidney cells, transfected with an expression vector containing the receptor cDNA, express an ∼ 190-kDa cell surface protein that is recognized by an anti-human PDGF receptor antibody. The recombinant PDGF receptor is functional in the transfected baby hamster kidney cells as demonstrated by ligand-induced phosphorylation of the receptor. Binding properties of the recombinant PDGF receptor were also assessed with pure preparations of BB and AB isoforms of PDGF. Unlike human dermal fibroblasts, which bind both isoforms with high affinity, the transfected baby hamster kidney cells bind only the BB isoform of PDGF with high affinity. This observation is consistent with the existence of more than one PDGF receptor class

  1. UAP56 is an important mediator of Angiotensin II/platelet derived growth factor induced vascular smooth muscle cell DNA synthesis and proliferation

    International Nuclear Information System (INIS)

    Sahni, Abha; Wang, Nadan; Alexis, Jeffrey

    2013-01-01

    Highlights: ► Knockdown of UAP56 inhibits Angiotensin II/PDGF induced vascular smooth muscle cell proliferation. ► UAP56 is a positive regulator of E2F transcriptional activation. ► UAP56 is present in the vessel wall of low flow carotid arteries. -- Abstract: Angiotensin (Ang) II and platelet-derived growth factor (PDGF) are important mediators of pathologic vascular smooth muscle cell (VSMC) proliferation. Identifying downstream mediators of Ang II and PDGF signaling may provide insights for therapies to improve vascular proliferative diseases. We have previously demonstrated that breakpoint cluster region (Bcr) is an important mediator of Ang II/PDGF signaling in VSMC. We have recently reported that the DExD/H box protein UAP56 is an interacting partner of Bcr in regulating VSMC DNA synthesis. We hypothesized that UAP56 itself is an important regulator of VSMC proliferation. In this report we demonstrate that knockdown of UAP56 inhibits Ang II/PDGF induced VSMC DNA synthesis and proliferation, and inhibits E2F transcriptional activity. In addition, we demonstrate that UAP56 is present in the vessel wall of low-flow carotid arteries. These findings suggest that UAP56 is a regulator of VSMC proliferation and identify UAP56 as a target for preventing vascular proliferative disease

  2. Structure activity relationships of quinoxalin-2-one derivatives as platelet-derived growth factor-beta receptor (PDGFbeta R) inhibitors, derived from molecular modeling.

    Science.gov (United States)

    Mori, Yoshikazu; Hirokawa, Takatsugu; Aoki, Katsuyuki; Satomi, Hisanori; Takeda, Shuichi; Aburada, Masaki; Miyamoto, Ken-ichi

    2008-05-01

    We previously reported a quinoxalin-2-one compound (Compound 1) that had inhibitory activity equivalent to existing platelet-derived growth factor-beta receptor (PDGFbeta R) inhibitors. Lead optimization of Compound 1 to increase its activity and selectivity, using structural information regarding PDGFbeta R-ligand interactions, is urgently needed. Here we present models of the PDGFbeta R kinase domain complexed with quinoxalin-2-one derivatives. The models were constructed using comparative modeling, molecular dynamics (MD) and ligand docking. In particular, conformations derived from MD, and ligand binding site information presented by alpha-spheres in the pre-docking processing, allowed us to identify optimal protein structures for docking of target ligands. By carrying out molecular modeling and MD of PDGFbeta R in its inactive state, we obtained two structural models having good Compound 1 binding potentials. In order to distinguish the optimal candidate, we evaluated the structural activity relationships (SAR) between the ligand-binding free energies and inhibitory activity values (IC50 values) for available quinoxalin-2-one derivatives. Consequently, a final model with a high SAR was identified. This model included a molecular interaction between the hydrophobic pocket behind the ATP binding site and the substitution region of the quinoxalin-2-one derivatives. These findings should prove useful in lead optimization of quinoxalin-2-one derivatives as PDGFb R inhibitors.

  3. Enhancement of distribution of dermal multipotent stem cells to bone marrow in rats of total body irradiation by platelet-derived growth factor-AA treatment

    International Nuclear Information System (INIS)

    Zong Zhaowen; Ren Yongchuan; Shen Yue; Chen Yonghua; Ran Xinze; Shi Chunmeng; Cheng Tianmin

    2011-01-01

    Objective: To observe whether dermal multipotent stem cells (dMSCs) treated with platelet-derived growth factor-AA (PDGF-AA) could distribute more frequently to the bone marrow in rats of total body irradiation (TBI). Methods: Male dMSCs were isolated and 10 μg/L PDGF-AA was added to the culture medium and further cultured for 2 h. Then the expression of tenascin-C were examined by Western blot, and the migration ability of dMSCs was assessed in transwell chamber. The pre-treated dMSCs were transplanted by tail vein injection into female rats administered with total body irradiation, and 2 weeks after transplantation, real-time PCR was employed to measure the amount of dMSCs in bone marrow. Non-treated dMSCs served as control.Results PDGF-AA treatment increased the expression of tenascin-C in dMSCs, made (1.79 ± 0.13) × 10 5 cells migrate to the lower chamber under the effect of bone marrow extract, and distributed to bone marrow in TBI rats, significantly more than (1.24 ± 0.09) ×10 5 in non-treated dMSCs (t=8.833, P<0.01). Conclusions: PDGF-AA treatment could enhance the migration ability of dMSCs and increase the amount of dMSCs in bone marrow of TBI rats after transplantation. (authors)

  4. Expressions of the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase genes are stimulated by recombinant platelet-derived growth factor isomers

    International Nuclear Information System (INIS)

    Roth, M.; Emmons, L.R.; Perruchoud, A.; Block, L.H.

    1991-01-01

    The plausible role that platelet-derived growth factor (PDGF) has in the localized pathophysiological changes that occur in the arterial wall during development of atherosclerotic lesions led the authors to investigate the influence of recombinant (r)PDGF isomers -AA, -AB, and -BB on the expression of low density lipoprotein receptor (LDL-R) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG0CoA) reductase [(S)-mevalonate:NAD + oxidoreductase (CoA-acylating), EC 1.1.1.88] genes. In addition, they clarified the role of protein kinase C (PKC) in expression of the two genes in human skin fibroblasts and vascular smooth muscle cells. The various rPDGF isoforms are distinct in their ability to activate transcription of both genes: (i) both rPDGF-AA and -BB stimulate transcription of the LDL-R gene; in contrast, rPDGF-BB but not -AA, activates transcription of the HMG-CoA reductase gene; (ii) all recombinant isoforms of PDGF activate transcription of the c-fos gene; (iii) while rPDGF-dependent transcription of the lDL-R gene occurs independently of PKC, transcription of the HMG-CoA reductase gene appears to involve the action of that enzyme

  5. Malignant melanoma of the nasal cavity: a case report with examination of KIT and platelet derived growth factor receptor-α (PDGFRA

    Directory of Open Access Journals (Sweden)

    Tadashi Terada

    2011-10-01

    Full Text Available Although several clinicopathological studies of malignant melanoma of the nasal cavity have been reported, there are no studies of the expression and gene mutation of KIT and platelet derived growth factor receptor-α (PDGFRA in melanoma of the nasal cavity. A 92-year-old Japanese woman consulted to our hospital because of right nasal obstruction and epistaxis. Physical examination and imaging modalities showed a tumor of the right nasal cavity. A biopsy was taken, and it showed malignant epithelioid cells with melanin deposition. Immunohistochemically, the tumor was positive for S100 protein, HMB45, p53, Ki-67 (labeling=20%, KIT and PDGFRA. The tumor was negative for cytokeratins (AE1/3 and CAM5.2. A genetic analysis using PCR-direct sequencing revealed no mutation of KIT gene (exons 9, 11, 13, and 17 or the PDGFRA gene (exons 12 and 18. The pathological diagnosis was primary malignant melanoma of the nasal cavity. The tumor was reduced in size by local resection and chemotherapy (Darthmose regimen: dacarbazine, carmustine, cisplatine, and tamoxifen, and the patient is now alive and free from metastasis 9 months after the first manifestation. In conclusion, the author reported a case of melanoma of the nasal cavity expressing KIT and PDGFRA without gene mutations of KIT and PDGFRA.

  6. Depletion of intracellular calcium stores facilitates the influx of extracellular calcium in platelet derived growth factor stimulated A172 glioblastoma cells.

    Science.gov (United States)

    Vereb, G; Szöllösi, J; Mátyus, L; Balázs, M; Hyun, W C; Feuerstein, B G

    1996-05-01

    Calcium signaling in non-excitable cells is the consequence of calcium release from intracellular stores, at times followed by entry of extracellular calcium through the plasma membrane. To study whether entry of calcium depends upon the level of saturation of intracellular stores, we measured calcium channel opening in the plasma membrane of single confluent A172 glioblastoma cells stimulated with platelet derived growth factor (PDGF) and/or bradykinin (BK). We monitored the entry of extracellular calcium by measuring manganese quenching of Indo-1 fluorescence. PDGF raised intracellular calcium concentration ([Ca2+]i) after a dose-dependent delay (tdel) and then opened calcium channels after a dose-independent delay (tch). At higher doses (> 3 nM), BK increased [Ca2+]i after a tdel approximately 0 s, and tch decreased inversely with both dose and peak [Ca2+]i. Experiments with thapsigargin (TG), BK, and PDGF indicated that BK and PDGF share intracellular Ca2+ pools that are sensitive to TG. When these stores were depleted by treatment with BK and intracellular BAPTA, tdel did not change, but tch fell to almost 0 s in PDGF stimulated cells, indicating that depletion of calcium stores affects calcium channel opening in the plasma membrane. Our data support the capacitative model for calcium channel opening and the steady-state model describing quantal Ca2+ release from intracellular stores.

  7. Expression and developmental control of platelet-derived growth factor A-chain and B-chain/Sis genes in rat aortic smooth muscle cells

    International Nuclear Information System (INIS)

    Majesky, M.W.; Benditt, E.P.; Schwartz, S.M.

    1988-01-01

    Cultured arterial smooth muscle cells (SMC) can produce platelet-derived growth factor (PDGF)-like molecules. This property raises the possibility that SMC-derived PDGFs function as autocrine/paracrine regulators in the formation and maintenance of the artery wall. In this study the authors have asked if levels of mRNAs directing synthesis of PDFG are modulated in aortic SMC during postnatal development. The authors report here that genes encoding PDGF A- and B-chain precursors are expressed at similar low levels in intact aortas from newborn and adult rats. Marked differences in regulation of transcript abundance of these genes were revealed when aortic SMC were grown in cell culture. PDGF B-chain transcripts accumulated in passaged newborn rat SMC but not adult rat SMC, whereas PDGF A-chain RNA was found in comparable amounts in SMC from both age groups. Similarly, SMC from newborn rats secreted at least 60-fold more PDGF-like activity into conditioned medium than did adult rat SMC. These results show that PDGF A- and B-chain genes are transcribed in the normal rat aorta and provide evidence for age-related change in the control of PDGF B-chain gene expression in aortic SMC. Independent regulation of transcript levels in cultured SMC leaves open the possibility that PDGFs of different composition (AA, AB, BB) play different roles in normal function of the artery wall

  8. Topical application of recombinant platelet-derived growth factor increases the rate of healing and the level of proteins that regulate this response.

    Science.gov (United States)

    Gowda, Santosh; Weinstein, David A; Blalock, Timothy D; Gandhi, Kavita; Mast, Bruce A; Chin, Gloria; Schultz, Gregory S

    2015-10-01

    A bipedicle ischaemic rat skin flap model was used to study the effects of daily topical applications of platelet-derived growth factor (PDGF) on the healing of ischaemic wounds. Levels of tumour necrosis factor-alpha (TNFA), interleukin 1-beta (IL1B) and both the latent and active forms of matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were measured. Full-thickness wounds were made on a total of 72 adult male Sprague-Dawley rats. Each group of 18 rats with normal and ischaemic wounds received either vehicle or 0·01% recombinant PDGF-BB. Additional applications were made on the wounds on a daily basis. Wound areas were measured at 0, 1, 3, 5, 7 9 and 13 days after wounding. Ischaemia caused a delay in wound healing as well as an increase in TNFA, IL1B and both the pro and active forms of MMP2 and MMP9. PDGF accelerated the rate of wound healing in both normal and ischaemic wounds and negated the effect of ischaemia. PDGF reduced the TNFA concentration in both normal and ischaemic wounds, and the rate of wound healing closely resembled the pattern of TNFA protein expression. PDGF also reduced both the magnitude and duration of the increases in IL1B and both the pro and active forms of MMP2 and MMP9 induced by ischaemia. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  9. Changes in Otx2 and Parvalbumin Immunoreactivity in the Superior Colliculus in the Platelet-Derived Growth Factor Receptor-β Knockout Mice

    Directory of Open Access Journals (Sweden)

    Juanjuan Zhao

    2013-01-01

    Full Text Available The superior colliculus (SC, a relay nucleus in the subcortical visual pathways, is implicated in socioemotional behaviors. Homeoprotein Otx2 and β subunit of receptors of platelet-derived growth factor (PDGFR-β have been suggested to play an important role in development of the visual system and development and maturation of GABAergic neurons. Although PDGFR-β-knockout (KO mice displayed socio-emotional deficits associated with parvalbumin (PV-immunoreactive (IR neurons, their anatomical bases in the SC were unknown. In the present study, Otx2 and PV-immunolabeling in the adult mouse SC were investigated in the PDGFR-β KO mice. Although there were no differences in distribution patterns of Otx2 and PV-IR cells between the wild type and PDGFR-β KO mice, the mean numbers of both of the Otx2- and PV-IR cells were significantly reduced in the PDGFR-β KO mice. Furthermore, average diameters of Otx2- and PV-IR cells were significantly reduced in the PDGFR-β KO mice. These findings suggest that PDGFR-β plays a critical role in the functional development of the SC through its effects on Otx2- and PV-IR cells, provided specific roles of Otx2 protein and PV-IR cells in the development of SC neurons and visual information processing, respectively.

  10. Comparative proteome approach demonstrates that platelet-derived growth factor C and D efficiently induce proliferation while maintaining multipotency of hMSCs

    Energy Technology Data Exchange (ETDEWEB)

    Sotoca, Ana M., E-mail: a.sotoca@science.ru.nl [Department of Cell and Applied Biology, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Roelofs-Hendriks, Jose [Department of Cell and Applied Biology, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Boeren, Sjef [Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen (Netherlands); Kraan, Peter M. van der [Department of Rheumatology Research and Advanced Therapeutics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Vervoort, Jacques [Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen (Netherlands); Zoelen, Everardus J.J. van; Piek, Ester [Department of Cell and Applied Biology, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen (Netherlands)

    2013-10-15

    This is the first study that comprehensively describes the effects of the platelet-derived growth factor (PDGF) isoforms C and D during in vitro expansion of human mesenchymal stem cells (hMSCs). Our results show that PDGFs can enhance proliferation of hMSCs without affecting their multipotency. It is of great value to culture and expand hMSCs in a safe and effective manner without losing their multipotency for manipulation and further development of cell-based therapies. Moreover, differential effects of PDGF isoforms have been observed on lineage-specific differentiation induced by BMP2 and Vitamin D3. Based on label-free LC-based quantitative proteomics approach we have furthermore identified specific pathways induced by PDGFs during the proliferation process, showing the importance of bioinformatics tools to study cell function. - Highlights: • PDGFs (C and D) significantly increased the number of multipotent undifferentiated hMSCs. • Enhanced proliferation did not impair the ability to undergo lineage-specific differentiation. • Proteomic analysis confirmed the overall signatures of the ‘intact’ cells.

  11. An aptamer-based biosensing platform for highly sensitive detection of platelet-derived growth factor via enzyme-mediated direct electrochemistry.

    Science.gov (United States)

    Deng, Kun; Xiang, Yang; Zhang, Liqun; Chen, Qinghai; Fu, Weiling

    2013-01-08

    In this work, a new label-free electrochemical aptamer-based sensor (aptasensor) was constructed for detection of platelet-derived growth factor (PDGF) based on the direct electrochemistry of glucose oxidase (GOD). For this proposed aptasensor, poly(diallyldimethylammonium chloride) (PDDA)-protected graphene-gold nanoparticles (P-Gra-GNPs) composite was firstly coated on electrode surface to form the interface with biocompatibility and huge surface area for the adsorption of GOD layer. Subsequently, gold nanoclusters (GNCs) were deposited on the surface of GOD to capture PDGF binding aptamer (PBA). Finally, GOD as a blocking reagent was employed to block the remaining active sites of the GNCs and avoid the nonspecific adsorption. With the direct electron transfer of double layer GOD membranes, the aptasensor showed excellent electrochemical response and the peak current decreased linearly with increasing logarithm of PDGF concentration from 0.005 nM to 60 nM with a relatively low limit of detection of 1.7 pM. The proposed aptasensor exhibited high specificity, good reproducibility and long-term stability, which provided a new promising technique for aptamer-based protein detection. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor.

    OpenAIRE

    Nishimura, R; Li, W; Kashishian, A; Mondino, A; Zhou, M; Cooper, J; Schlessinger, J

    1993-01-01

    Autophosphorylation sites of growth factor receptors with tyrosine kinase activity function as specific binding sites for Src homology 2 (SH2) domains of signaling molecules. This interaction appears to be a crucial step in a mechanism by which receptor tyrosine kinases relay signals to downstream signaling pathways. Nck is a widely expressed protein consisting exclusively of SH2 and SH3 domains, the overexpression of which causes cell transformation. It has been shown that various growth fac...

  13. Platelet-derived growth factor (PDGF)-signaling mediates radiation-induced apoptosis in human prostate cancer cells with loss of p53 function

    International Nuclear Information System (INIS)

    Kim, Harold E.; Han, Sue J.; Kasza, Thomas; Han, Richard; Choi, Hyeong-Seon; Palmer, Kenneth C.; Kim, Hyeong-Reh C.

    1997-01-01

    Platelet-derived growth factor (PDGF) signals a diversity of cellular responses in vitro, including cell proliferation, survival, transformation, and chemotaxis. PDGF functions as a 'competence factor' to induce a set of early response genes expressed in G 1 including p21 WAF1/CIP1 , a functional mediator of the tumor suppressor gene p53 in G 1 /S checkpoint. For PDGF-stimulated cells to progress beyond G 1 and transit the cell cycle completely, progression factors in serum such as insulin and IGF-1 are required. We have recently shown a novel role of PDGF in inducing apoptosis in growth-arrested murine fibroblasts. The PDGF-induced apoptosis is rescued by insulin, suggesting that G 1 /S checkpoint is a critical determinant for PDGF-induced apoptosis. Because recent studies suggest that radiation-induced signal transduction pathways interact with growth factor-mediated signaling pathways, we have investigated whether activation of the PDGF-signaling facilitates the radiation-induced apoptosis in the absence of functional p53. For this study we have used the 125-IL cell line, a mutant p53-containing, highly metastatic, and hormone-unresponsive human prostate carcinoma cell line. PDGF signaling is constitutively activated by transfection with a p28 v-sis expression vector, which was previously shown to activate PDGF α- and β- receptors. Although the basal level of p21 WAF1/CIP1 expression and radiation-induced apoptosis were not detectable in control 125-IL cells as would be predicted in mutant p53-containing cells, activation of PDGF-signaling induced expression of p21 WAF1/CIP1 and radiation-induced apoptosis. Our study suggests that the level of 'competence' growth factors including PDGF may be one of the critical determinants for radiation-induced apoptosis, especially in cells with loss of p53 function at the site of radiotherapy in vivo

  14. Effect of plasma-rich in platelet-derived growth factors on peri-implant bone healing: An experimental study in canines

    Science.gov (United States)

    Birang, Reza; Torabi, Alireza; Shahabooei, Mohammad; Rismanchian, Mansour

    2012-01-01

    Background: Tissue engineering principles can be exploited to enhance alveolar and peri-implant bone reconstruction by applying such biological factors as platelet-derived growth factors. The objective of the present study is to investigate the effect of autologous plasma-rich in growth factors (on the healing of peri-implant bone in canine mandible). Materials and Methods: In this prospective experimental animal study, two healthy canines of the Iranian mix breed were selected. Three months after removing their premolar teeth on both sides of the mandible, 12 implants of the Osteo Implant Corporationsystem, 5 mm in diameter and 10 mm in length, were selected to be implanted. Plasma rich in growth factors (PRGF) were applied on six implants while the other six were used as plain implants without the plasma. The implants were installed in osteotomy sites on both sides of the mandible to be removed after 4 weeks with the surrounding bones using a trephine bur. Mesio-distal sections and implant blocks, 50 μ in diameter containing the peri-implant bone, were prepared By basic fuchin toluidine-bluefor histological and histomorphometric evaluation by optical microscope. The data were analyzed using Mann-Whitney Test (PPRGF and control groups had no statistically significant differences (P=0.261, P=0.2) although the parameters showed higher measured values in the PRGF group. However, compared to the control, application of PRGF had significantly increased bone-to-implant contact (P=0.028) Conclusion: Based on the results, it may be concluded that application of PRGF on the surface of implant may enhance bone-to-implant contact. PMID:22363370

  15. Immunohistochemical expression of platelet-derived growth factor receptors in ovarian cancer patients with long-term follow-up

    DEFF Research Database (Denmark)

    Madsen, Christine Vestergaard; Dahl Steffensen, Karina; Waldstrøm, Marianne

    2012-01-01

    relation to histopathological parameters and long-term overall survival. Methods. The immunohistochemical expression of PDGFR-α and PDGFR-β was investigated in tumor and stromal cells in 170 patients with histologically verified epithelial ovarian cancer. Results. Almost half of the tumor specimens showed......Introduction. The well-documented role of the PDGF system in tumor growth and angiogenesis has prompted the development of new biological agents targeting the PDGF system. The aim of the present study was to analyze the expression of the PDGF-receptors in ovarian cancer and to investigate its...... high expression of PDGFR-α and PDGFR-β in tumor cells (43% and 41%) and in stromal compartments (32% and 44%). There was a significant association between high expression of PDGFR-α and high expression of PDGFR-β in both tumor and stromal cells. Coexpression of PDGFR-α and PDGFR-β in stromal cells...

  16. Platelet-derived growth factor-D modulates extracellular matrix homeostasis and remodeling through TIMP-1 induction and attenuation of MMP-2 and MMP-9 gelatinase activities

    International Nuclear Information System (INIS)

    Borkham-Kamphorst, Erawan; Alexi, Pascal; Tihaa, Lidia; Haas, Ute; Weiskirchen, Ralf

    2015-01-01

    Platelet-derived growth factor-D (PDGF-D) is a more recent recognized growth factor involved in the regulation of several cellular processes, including cell proliferation, transformation, invasion, and angiogenesis by binding to and activating its cognate receptor PDGFR-β. After bile duct ligation or in the carbon tetrachloride-induced hepatic fibrosis model , PDGF-D showed upregulation comparable to PDGF-B. Moreover, adenoviral PDGF-D gene transfer induced hepatic stellate cell proliferation and liver fibrosis. We here investigated the molecular mechanism of PDGF-D involvement in liver fibrogenesis. Therefore, the GRX mouse cell line was stimulated with PDGF-D and evaluated for fibrotic markers and PDGF-D signaling pathways in comparison to the other PDGF isoforms. We found that PDGF-D failed to enhance Col I and α-smooth muscle actin (α-SMA) production but has capacity to upregulate expression of the tissue inhibitor of metalloprotease 1 (TIMP-1) resulting in attenuation of MMP-2 and MMP-9 gelatinase activity as indicated by gelatinase zymography. This phenomenon was restored through application of a PDGF-D neutralizing antibody. Unexpectedly, PDGF-D incubation decreased both PDGFR-α and -β in mRNA and protein levels, and PDGF-D phosphorylated typrosines specific for PDGFR-α and -β. We conclude that PDGF-D intensifies fibrogenesis by interfering with the fibrolytic activity of the TIMP-1/MMP system and that PDGF-D signaling is mediated through both PDGF-α and -β receptors. - Highlights: • PDGF-D signals through PDGF receptor type α and β. • PDGF-D modulates extracellular matrix homeostasis and remodeling. • Like PDGF-B, PDGF-D triggers phosphorylation of PLC-γ, Akt/PKB, JNK, ERK1/2, and p38. • PDGF-D induces TIMP-1 expression through ERK and p38 MAPK. • PDGF-D attenuates MMP-2 and MMP-9 gelatinase activities

  17. Platelet-derived growth factor BB and DD and angiopoietin1 are altered in follicular fluid from polycystic ovary syndrome patients.

    Science.gov (United States)

    Scotti, Leopoldina; Parborell, Fernanda; Irusta, Griselda; De Zuñiga, Ignacio; Bisioli, Claudio; Pettorossi, Hernan; Tesone, Marta; Abramovich, Dalhia

    2014-08-01

    Polycystic ovary syndrome (PCOS) is the most common endocrinological pathology among women of reproductive age, and is characterized by abnormalities in ovarian angiogenesis, among other features. Consistent with this association, follicular fluid (FF) concentration and ovarian expression of vascular endothelial growth factor (VEGF) are increased in PCOS patients. In this study, we examined the protein levels of platelet-derived growth factor (PDGF) BB and DD (PDGFBB and PDGFDD), angiopoietin 1 and 2 (ANGPT1 and ANGPT2), and their soluble receptor sTIE2 in FF from PCOS and control patients undergoing assisted reproductive techniques. We also analyzed the effect of FF from PCOS and control patients on tight and adherens junction protein expression in an endothelial cell line. PDGFBB and PDGFDD were significantly lower whereas ANGPT1 concentration was significantly higher in FF from PCOS patients than from control patients. No changes were found in the concentration of ANGPT2 or sTIE2. Expression of claudin-5 was significantly increased in endothelial cells incubated for 24 hr in the presence of FF from PCOS versus from control patients, while vascular-endothelial cadherin, β-catenin, and zonula occludens 1 expression were unchanged. The changes observed in the levels of PDGF isoforms and ANGPT1 may prevent VEGF-induced vascular permeability in the PCOS ovary by regulating endothelial-cell-junction protein levels. Restoring the levels of angiogenic factors may provide new insights into PCOS treatment and the prevention of ovarian hyperstimulation syndrome in affected women. © 2014 Wiley Periodicals, Inc.

  18. Activated platelet-derived growth factor autocrine pathway drives the transformed phenotype of a human glioblastoma cell line.

    Science.gov (United States)

    Vassbotn, F S; Ostman, A; Langeland, N; Holmsen, H; Westermark, B; Heldin, C H; Nistér, M

    1994-02-01

    Human glioblastoma cells (A172) were found to concomitantly express PDGF-BB and PDGF beta-receptors. The receptors were constitutively autophosphorylated in the absence of exogenous ligand, suggesting the presence of an autocrine PDGF pathway. Neutralizing PDGF antibodies as well as suramin inhibited the autonomous PDGF receptor tyrosine kinase activity and resulted in up-regulation of receptor protein. The interruption of the autocrine loop by the PDGF antibodies reversed the transformed phenotype of the glioblastoma cell, as determined by (1) diminished DNA synthesis, (2) inhibition of tumor colony growth, and (3) reversion of the transformed morphology of the tumor cells. The PDGF antibodies showed no effect on the DNA synthesis of another glioblastoma cells line (U-343MGa 31L) or on Ki-ras-transformed fibroblasts. The present study demonstrates an endogenously activated PDGF pathway in a spontaneous human glioblastoma cell line. Furthermore, we provide evidence that the autocrine PDGF pathway drives the transformed phenotype of the tumor cells, a process that can be blocked by extracellular antagonists.

  19. MiR-34a inhibits colon cancer proliferation and metastasis by inhibiting platelet-derived growth factor receptor α.

    Science.gov (United States)

    Li, Chunyan; Wang, Yulin; Lu, Shuming; Zhang, Zhuqing; Meng, Hua; Liang, Lina; Zhang, Yan; Song, Bo

    2015-11-01

    The microRNA (miRNA), miR‑34a is significant in colon cancer progression. In the present study, the role of miR‑34a in colon cancer cell proliferation and metastasis was investigated. It was found that the expression of miR‑34a in colon cancer tissues and cell lines was lower when compared with that of normal tissues and cells. Further research demonstrated that miR‑34a inhibited cell proliferation, induced G1 phase arrest, and suppressed metastasis and epithelial mesenchymal transition in colon cancer cells. Bioinformatic prediction indicated that platelet‑derived growth factor receptor α (PDGFRA) was a potential target gene of miR‑34a and a luciferase assay identified that PDGFRA was a novel direct target gene of miR‑34a. In addition, assays of western blot analyses and quantitative reverse‑transcription polymerase chain reaction confirmed that miR‑34a decreased PDGFRA mRNA expression and protein levels in colon cancer cells. Assessment of cellular function indicated that miR‑34a inhibited colon cancer progression via PDGFRA. These findings demonstrate that miR‑34a may act as a negative regulator in colon cancer by targeting PDGFRA.

  20. Neomycin is a platelet-derived growth factor (PDGF) antagonist that allows discrimination of PDGF alpha- and beta-receptor signals in cells expressing both receptor types.

    Science.gov (United States)

    Vassbotn, F S; Ostman, A; Siegbahn, A; Holmsen, H; Heldin, C H

    1992-08-05

    The aminoglycoside neomycin has recently been found to affect certain platelet-derived growth factor (PDGF) responses in C3H/10T1/2 C18 fibroblasts. Using porcine aortic endothelial cells transfected with PDGF alpha- or beta-receptors, we explored the possibility that neomycin interferes with the interaction between the different PDGF isoforms and their receptors. We found that neomycin (5 mM) inhibited the binding of 125I-PDGF-BB to the alpha-receptor with only partial effect on the binding of 125I-PDGF-AA; in contrast, the binding of 125I-PDGF-BB to the beta-receptor was not affected by the aminoglycoside. Scatchard analyses showed that neomycin (5 mM) decreased the number of binding sites for PDGF-BB on alpha-receptor-expressing cells by 87%. Together with cross-competition studies with 125I-labeled PDGF homodimers, the effect of neomycin indicates that PDGF-AA and PDGF-BB bind to both common and unique structures on the PDGF alpha-receptor. Neomycin specifically inhibited the autophosphorylation of the alpha-receptor by PDGF-BB, with less effect on the phosphorylation induced by PDGF-AA and no effect on the phosphorylation of the beta-receptor by PDGF-BB. Thus, neomycin is a PDGF isoform- and receptor-specific antagonist that provides a possibility to compare the signal transduction pathways of alpha- and beta-receptors in cells expressing both receptor types. This approach was used to show that activation of PDGF beta-receptors by PDGF-BB mediated a chemotactic response in human fibroblasts, whereas activation of alpha-receptors by the same ligand inhibited chemotaxis.

  1. Enrichment of putative pancreatic progenitor cells from mice by sorting for prominin1 (CD133) and platelet-derived growth factor receptor beta.

    Science.gov (United States)

    Hori, Yuichi; Fukumoto, Miki; Kuroda, Yoshikazu

    2008-11-01

    Success in islet transplantation-based therapies for type 1 diabetes mellitus and an extreme shortage of pancreatic islets have motivated recent efforts to develop renewable sources of islet-replacement tissue. Although pancreatic progenitor cells hold a promising potential, only a few attempts have been made at the prospective isolation of pancreatic stem/progenitor cells, because of the lack of specific markers and the development of effective cell culture methods. We found that prominin1 (also known as CD133) recognized the undifferentiated epithelial cells, whereas platelet-derived growth factor receptor beta (PDGFRbeta) was expressed on the mesenchymal cells in the mouse embryonic pancreas. We then developed an isolation method for putative stem/progenitor cells by flow cytometric cell sorting and characterized their potential for differentiation to pancreatic tissue using both in vitro and in vivo protocols. Flow cytometry and the subsequent reverse transcription-polymerase chain reaction and microarray analysis revealed pancreatic epithelial progenitor cells to be highly enriched in the prominin1(high)PDGFRbeta(-) cell population. During in vivo differentiation, these cell populations were able to differentiate into endocrine, exocrine, and ductal tissues, including the formation of an insulin-producing cell cluster. We established the prospective isolation of putative pancreatic epithelial progenitor cells by sorting for prominin1 and PDGFRbeta. Since this strategy is based on the cell surface markers common to human and rodents, these findings may lead to the development of new strategies to derive transplantable islet-replacement tissues from human pancreatic stem/progenitor cells. Disclosure of potential conflicts of interest is found at the end of this article.

  2. Ligustrazine attenuates oxidative stress-induced activation of hepatic stellate cells by interrupting platelet-derived growth factor-β receptor-mediated ERK and p38 pathways

    International Nuclear Information System (INIS)

    Zhang, Feng; Ni, Chunyan; Kong, Desong; Zhang, Xiaoping; Zhu, Xiaojing; Chen, Li; Lu, Yin; Zheng, Shizhong

    2012-01-01

    Hepatic fibrosis represents a frequent event following chronic insult to trigger wound healing reactions with accumulation of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is the pivotal event during liver fibrogenesis. Compelling evidence indicates that oxidative stress is concomitant with liver fibrosis irrespective of the underlying etiology. Natural antioxidant ligustrazine exhibits potent antifibrotic activities, but the mechanisms are poorly understood. Our studies were to investigate the ligustrazine effects on HSC activation stimulated by hydrogen peroxide (H 2 O 2 ), an in vitro model mimicking the oxidative stress in liver fibrogenesis, and to elucidate the possible mechanisms. Our results demonstrated that H 2 O 2 at 5 μM significantly stimulated HSC proliferation and expression of marker genes of HSC activation; whereas ligustrazine dose-dependently suppressed proliferation and induced apoptosis in H 2 O 2 -activated HSCs, and attenuated expression of fibrotic marker genes. Mechanistic investigations revealed that ligustrazine reduced platelet-derived growth factor-β receptor (PDGF-βR) expression and blocked the phosphorylation of extracellular regulated protein kinase (ERK) and p38 kinase, two downstream effectors of PDGF-βR. Further molecular evidence suggested that ligustrazine interruption of ERK and p38 pathways was dependent on the blockade of PDGF-βR and might be involved in ligustrazine reduction of fibrotic marker gene expression under H 2 O 2 stimulation. Furthermore, ligustrazine modulated some proteins critical for HSC activation and ECM homeostasis in H 2 O 2 -stimulated HSCs. These data collectively indicated that ligustrazine could attenuate HSC activation caused by oxidative stress, providing novel insights into ligustrazine as a therapeutic option for hepatic fibrosis. Highlights: ► Ligustrazine inhibits oxidative stress-induced HSC activation. ► Ligustrazine reduces fibrotic marker genes

  3. The inhibitory effect of dexamethasone on platelet-derived growth factor-induced vascular smooth muscle cell migration through up-regulating PGC-1α expression

    International Nuclear Information System (INIS)

    Xu, Wei; Guo, Ting; Zhang, Yan; Jiang, Xiaohong; Zhang, Yongxian; Zen, Ke; Yu, Bo; Zhang, Chen-Yu

    2011-01-01

    Dexamethasone has been shown to inhibit vascular smooth muscle cell (VSMC) migration, which is required for preventing restenosis. However, the mechanism underlying effect of dexamethasone remains unknown. We have previously demonstrated that peroxisome proliferator-activated receptor gamma (PPARγ) coactivator-1 alpha (PGC-1α) can inhibit VSMC migration and proliferation. Here, we investigated the role of PGC-1α in dexamethasone-reduced VSMC migration and explored the possible mechanism. We first examined PGC-1α expression in cultured rat aortic VSMCs. The results revealed that incubation of VSMCs with dexamethasone could significantly elevate PGC-1α mRNA expression. In contrast, platelet-derived growth factor (PDGF) decreased PGC-1α expression while stimulating VSMC migration. Mechanistic study showed that suppression of PGC-1α by small interfering RNA strongly abrogated the inhibitory effect of dexamethasone on VSMC migration, whereas overexpression of PGC-1α had the opposite effect. Furthermore, an analysis of MAPK signal pathways showed that dexamethasone inhibited ERK and p38 MAPK phosphorylation in VSMCs. Overexpression of PGC-1α decreased both basal and PDGF-induced p38 MAPK phosphorylation, but it had no effect on ERK phosphorylation. Finally, inhibition of PPARγ activation by a PPARγ antagonist GW9662 abolished the suppressive effects of PGC-1α on p38 MAPK phosphorylation and VSMC migration. These effects of PGC-1α were enhanced by a PPARγ agonist troglitazone. Collectively, our data indicated for the first time that one of the anti-migrated mechanisms of dexamethasone is due to the induction of PGC-1α expression. PGC-1α suppresses PDGF-induced VSMC migration through PPARγ coactivation and, consequently, p38 MAPK inhibition.

  4. Platelet-derived growth factor receptor-β, carrying the activating mutation D849N, accelerates the establishment of B16 melanoma

    International Nuclear Information System (INIS)

    Suzuki, Shioto; Heldin, Carl-Henrik; Heuchel, Rainer Lothar

    2007-01-01

    Platelet-derived growth factor (PDGF)-BB and PDGF receptor (PDGFR)-β are mainly expressed in the developing vasculature, where PDGF-BB is produced by endothelial cells and PDGFR-β is expressed by mural cells, including pericytes. PDGF-BB is produced by most types of solid tumors, and PDGF receptor signaling participates in various processes, including autocrine stimulation of tumor cell growth, recruitment of tumor stroma fibroblasts, and stimulation of tumor angiogenesis. Furthermore, PDGF-BB-producing tumors are characterized by increased pericyte abundance and accelerated tumor growth. Thus, there is a growing interest in the development of tumor treatment strategies by blocking PDGF/PDGFR function. We have recently generated a mouse model carrying an activated PDGFR-β by replacing the highly conserved aspartic acid residue (D) 849 in the activating loop with asparagine (N). This allowed us to investigate, in an orthotopic tumor model, the role of increased stromal PDGFR-β signaling in tumor-stroma interactions. B16 melanoma cells lacking PDGFR-β expression and either mock-transfected or engineered to express PDGF-BB, were injected alone or in combination with matrigel into mice carrying the activated PDGFR-β (D849N) and into wild type mice. The tumor growth rate was followed and the vessel status of tumors, i.e. total vessel area/tumor, average vessel surface and pericyte density of vessels, was analyzed after resection. Tumors grown in mice carrying an activated PDGFR-β were established earlier than those in wild-type mice. In this early phase, the total vessel area and the average vessel surface were higher in tumors grown in mice carrying the activated PDGFR-β (D849N) compared to wild-type mice, whereas we did not find a significant difference in the number of tumor vessels and the pericyte abundance around tumor vessels between wild type and mutant mice. At later phases of tumor progression, no significant difference in tumor growth rate was

  5. Platelet-derived growth factor-D modulates extracellular matrix homeostasis and remodeling through TIMP-1 induction and attenuation of MMP-2 and MMP-9 gelatinase activities

    Energy Technology Data Exchange (ETDEWEB)

    Borkham-Kamphorst, Erawan, E-mail: ekamphorst@ukaachen.de; Alexi, Pascal; Tihaa, Lidia; Haas, Ute; Weiskirchen, Ralf, E-mail: rweiskirchen@ukaachen.de

    2015-02-13

    Platelet-derived growth factor-D (PDGF-D) is a more recent recognized growth factor involved in the regulation of several cellular processes, including cell proliferation, transformation, invasion, and angiogenesis by binding to and activating its cognate receptor PDGFR-β. After bile duct ligation or in the carbon tetrachloride-induced hepatic fibrosis model{sub ,} PDGF-D showed upregulation comparable to PDGF-B. Moreover, adenoviral PDGF-D gene transfer induced hepatic stellate cell proliferation and liver fibrosis. We here investigated the molecular mechanism of PDGF-D involvement in liver fibrogenesis. Therefore, the GRX mouse cell line was stimulated with PDGF-D and evaluated for fibrotic markers and PDGF-D signaling pathways in comparison to the other PDGF isoforms. We found that PDGF-D failed to enhance Col I and α-smooth muscle actin (α-SMA) production but has capacity to upregulate expression of the tissue inhibitor of metalloprotease 1 (TIMP-1) resulting in attenuation of MMP-2 and MMP-9 gelatinase activity as indicated by gelatinase zymography. This phenomenon was restored through application of a PDGF-D neutralizing antibody. Unexpectedly, PDGF-D incubation decreased both PDGFR-α and -β in mRNA and protein levels, and PDGF-D phosphorylated typrosines specific for PDGFR-α and -β. We conclude that PDGF-D intensifies fibrogenesis by interfering with the fibrolytic activity of the TIMP-1/MMP system and that PDGF-D signaling is mediated through both PDGF-α and -β receptors. - Highlights: • PDGF-D signals through PDGF receptor type α and β. • PDGF-D modulates extracellular matrix homeostasis and remodeling. • Like PDGF-B, PDGF-D triggers phosphorylation of PLC-γ, Akt/PKB, JNK, ERK1/2, and p38. • PDGF-D induces TIMP-1 expression through ERK and p38 MAPK. • PDGF-D attenuates MMP-2 and MMP-9 gelatinase activities.

  6. Platelet-derived growth factor (PDGF-BB-mediated induction of monocyte chemoattractant protein 1 in human astrocytes: implications for HIV-associated neuroinflammation

    Directory of Open Access Journals (Sweden)

    Bethel-Brown Crystal

    2012-12-01

    Full Text Available Abstract Chemokine (C-C motif ligand 2, also known as monocyte chemoattractant protein 1 (MCP-1 is an important factor for the pathogenesis of HIV-associated neurocognitive disorders (HAND. The mechanisms of MCP-1-mediated neuropathogenesis, in part, revolve around its neuroinflammatory role and the recruitment of monocytes into the central nervous system (CNS via the disrupted blood-brain barrier (BBB. We have previously demonstrated that HIV-1/HIV-1 Tat upregulate platelet-derived growth factor (PDGF-BB, a known cerebrovascular permeant; subsequently, the present study was aimed at exploring the regulation of MCP-1 by PDGF-BB in astrocytes with implications in HAND. Specifically, the data herein demonstrate that exposure of human astrocytes to HIV-1 LAI elevated PDGF-B and MCP-1 levels. Furthermore, treating astrocytes with the human recombinant PDGF-BB protein significantly increased the production and release of MCP-1 at both the RNA and protein levels. MCP-1 induction was regulated by activation of extracellular-signal-regulated kinase (ERK1/2, c-Jun N-terminal kinase (JNK and p38 mitogen-activated protein (MAP kinases and phosphatidylinositol 3-kinase (PI3K/Akt pathways and the downstream transcription factor, nuclear factor κB (NFκB. Chromatin immunoprecipitation (ChIP assays demonstrated increased binding of NFκB to the human MCP-1 promoter following PDGF-BB exposure. Conditioned media from PDGF-BB-treated astrocytes increased monocyte transmigration through human brain microvascular endothelial cells (HBMECs, an effect that was blocked by STI-571, a tyrosine kinase inhibitor (PDGF receptor (PDGF-R blocker. PDGF-BB-mediated release of MCP-1 was critical for increased permeability in an in vitro BBB model as evidenced by blocking antibody assays. Since MCP-1 is linked to disease severity, understanding its modulation by PDGF-BB could aid in understanding the proinflammatory responses in HAND. These results suggest that astrocyte

  7. The platelet-derived growth factor signaling system in snapping turtle embryos, Chelydra serpentina: potential role in temperature-dependent sex determination and testis development.

    Science.gov (United States)

    Rhen, Turk; Jangula, Adam; Schroeder, Anthony; Woodward-Bosh, Rikki

    2009-05-01

    The platelet-derived growth factor (Pdgf) signaling system is known to play a significant role during embryonic and postnatal development of testes in mammals and birds. In contrast, genes that comprise the Pdgf system in reptiles have never been cloned or studied in any tissue, let alone developing gonads. To explore the potential role of PDGF ligands and their receptors during embryogenesis, we cloned cDNA fragments of Pdgf-A, Pdgf-B, and receptors PdgfR-alpha and PdgfR-beta in the snapping turtle, a reptile with temperature-dependent sex determination (TSD). We then compared gene expression profiles in gonads from embryos incubated at a male-producing temperature to those from embryos at a female-producing temperature, as well as between hatchling testes and ovaries. Expression of Pdgf-B mRNA in embryonic gonads was significantly higher at a male temperature than at a female temperature, but there was no difference between hatchling testes and ovaries. This developmental pattern was reversed for Pdgf-A and PdgfR-alpha mRNA: expression of these genes did not differ in embryos, but diverged in hatchling testes and ovaries. Levels of PdgfR-beta mRNA in embryonic gonads were not affected by temperature and did not differ between testes and ovaries. However, expression of both receptors increased at least an order of magnitude from the embryonic to the post-hatching period. Finally, we characterized expression of these genes in several other embryonic tissues. The brain, heart, and liver displayed unique expression patterns that distinguished these tissues from each other and from intestine, lung, and muscle. Incubation temperature had a significant effect on expression of PdgfR-alpha and PdgfR-beta in the heart but not other tissues. Together, these findings demonstrate that temperature has tissue specific effects on the Pdgf system and suggest that Pdgf signaling is involved in sex determination and the ensuing differentiation of testes in the snapping turtle.

  8. Local Application of Gelatin Hydrogel Sheets Impregnated With Platelet-Derived Growth Factor BB Promotes Tendon-to-Bone Healing After Rotator Cuff Repair in Rats.

    Science.gov (United States)

    Tokunaga, Takuya; Ide, Junji; Arimura, Hitoshi; Nakamura, Takayuki; Uehara, Yusuke; Sakamoto, Hidetoshi; Mizuta, Hiroshi

    2015-08-01

    To determine whether the local application of platelet-derived growth factor BB (PDGF-BB) in hydrogel sheets would promote healing and improve histologic characteristics and biomechanical strength after rotator cuff (RC) repair in rats. To assess the effect of PDGF-BB on tendon-to-bone healing we divided 36 adult male Sprague-Dawley rats treated with bilateral surgery to repair the supraspinatus tendon at its insertion site into 3 groups: group 1 = suture-only group; group 2 = suture and gelatin hydrogel sheets impregnated with phosphate-buffered saline (PBS); and group 3 = suture and gelatin hydrogel sheets impregnated with PDGF-BB (0.5 μg). Semiquantitative histologic evaluation was carried out 2, 6, and 12 weeks later; cell proliferation was assessed 2 and 6 weeks postoperatively by immunostaining for proliferating cell nuclear antigen (PCNA), and biomechanical testing, including ultimate load to failure, stiffness, and ultimate stress to failure, was performed 12 weeks after the operation. At 2 weeks, the average percentage of PCNA-positive cells at the insertion site was significantly higher in group 3 (40.5% ± 2.4%) than in group 1 (32.1% ± 6.9%; P = .03) and group 2 (31.9% ± 3.7%; P = .02). At 2 and 6 weeks, the histologic scores were similar among the 3 groups. At 12 weeks, the histologic score was significantly higher in group 3 (10.3 ± 0.8) than in group 1 (8.5 ± 0.5; P = .002) or group 2 (8.8 ± 0.8; P = .009), whereas ultimate load to failure, stiffness, and ultimate load to stress (normal control population, 44.73 ± 9.75 N, 27.59 ± 4.32 N/mm, and 21.33 ± 4.65 N/mm(2), respectively) were significantly higher in group 3 (28.28 ± 6.28 N, 11.05 ± 2.37 N/mm, and 7.99 ± 2.13 N/mm(2), respectively) than in group 1 (10.44 ± 1.98 N, 4.74 ± 1.31 N/mm, and 3.28 ± 1.27 N/mm(2), respectively; all P repair in humans. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  9. Pretreatment with platelet derived growth factor-BB modulates the ability of costochondral resting zone chondrocytes incorporated into PLA/PGA scaffolds to form new cartilage in vivo.

    Science.gov (United States)

    Lohmann, C H; Schwartz, Z; Niederauer, G G; Carnes, D L; Dean, D D; Boyan, B D

    2000-01-01

    Optimal repair of chondral defects is likely to require both a suitable population of chondrogenic cells and a biodegradable matrix to provide a space-filling structural support during the early stages of cartilage formation. This study examined the ability of chondrocytes to support cartilage formation when incorporated into biodegradable scaffolds constructed from copolymers (PLG) of polylactic acid (PLA) and polyglycolic acid (PGA) and implanted in the calf muscle of nude mice. Scaffolds were fabricated to be more hydrophilic (PLG-H) or were reinforced with 10% PGA fibers (PLG-FR), increasing the stiffness of the implant by 20-fold. Confluent primary cultures of rat costochondral resting zone chondrocytes (RC) were loaded into PLG-H foams and implanted intramuscularly. To determine if growth factor pretreatment could modulate the ability of the cells to form new cartilage, RC cells were pretreated with recombinant human platelet derived growth factor-BB IPDGF-BB) for 4 or 24 h prior to implantation. To assess whether scaffold material properties could affect the ability of chondrogenic cells to form cartilage, RC cells were also loaded into PLG-FR scaffolds. To determine if the scaffolds or treatment with PDGF-BB affected the rate of chondrogenesis, tissue at the implant site was harvested at four and eight weeks post-operatively, fixed, decalcified and embedded in paraffin. Sections were obtained along the transverse plane of the lower leg, stained with haematoxylin and eosin, and then assessed by morphometric analysis for area of cartilage, area of residual implant, and area of fibrous connective tissue formation (fibrosis). Whether or not the cartilage contained hypertrophic cells was also assessed. The amount of residual implant did not change with time in any of the implanted tissues. The area occupied by PLG-FR implants was greater than that occupied by PLG-H implants at both time points. All implants were surrounded by fibrous connective tissue, whether

  10. Potential of pomegranate fruit extract (Punica granatum Linn.) to increase vascular endothelial growth factor and platelet-derived growth factor expressions on the post-tooth extraction wound of Cavia cobaya.

    Science.gov (United States)

    Nirwana, Intan; Rachmadi, Priyawan; Rianti, Devi

    2017-08-01

    Pomegranates fruit extracts have several activities, among others, anti-inflammatory, antibacterial, and antioxidants that have the main content punicalagin and ellagic acid. Pomegranate has the ability of various therapies through different mechanisms. Vascular endothelial growth factor (VEGF) function was to form new blood vessels produced by various cells one of them was macrophages. Platelet-derived growth factor (PDGF) was a growth factor proven chemotactic, increased fibroblast proliferation and collagen matrix production. In addition, VEGF and PDGF synergize in their ability to vascularize tissues. The PDGF function was to stabilize and regulate maturation of new blood vessels. Activities of pomegranate fruit extract were observed by measuring the increased of VEGF and PDGF expression as a marker of wound healing process. To investigate the potential of pomegranate extracts on the tooth extraction wound to increase the expression of VEGF and PDGF on the 4 th day of wound healing process. This study used 12 Cavia cobaya , which were divided into two groups, namely, the provision of 3% sodium carboxymethyl cellulose and pomegranate extract. The 12 C. cobaya would be executed on the 4 th day, the lower jaw of experimental animals was taken, decalcified about 30 days. The expression of VEGF and PDGF was examined using immunohistochemical techniques. The differences of VEGF and PDGF expression were evaluated statistically using t-test. Statistically analysis showed that there were significant differences between control and treatment groups (p<0.05). Pomegranate fruit extract administration increased VEGF and PDGF expression on post-tooth extraction wound.

  11. Mammary tumors that become independent of the type I insulin-like growth factor receptor express elevated levels of platelet-derived growth factor receptors

    Directory of Open Access Journals (Sweden)

    Campbell Craig I

    2011-11-01

    Full Text Available Abstract Background Targeted therapies are becoming an essential part of breast cancer treatment and agents targeting the type I insulin-like growth factor receptor (IGF-IR are currently being investigated in clinical trials. One of the limitations of targeted therapies is the development of resistant variants and these variants typically present with unique gene expression patterns and characteristics compared to the original tumor. Results MTB-IGFIR transgenic mice, with inducible overexpression of the IGF-IR were used to model mammary tumors that develop resistance to IGF-IR targeting agents. IGF-IR independent mammary tumors, previously shown to possess characteristics associated with EMT, were found to express elevated levels of PDGFRα and PDGFRβ. Furthermore, these receptors were shown to be inversely expressed with the IGF-IR in this model. Using cell lines derived from IGF-IR-independent mammary tumors (from MTB-IGFIR mice, it was demonstrated that PDGFRα and to a lesser extent PDGFRβ was important for cell migration and invasion as RNAi knockdown of PDGFRα alone or PDGFRα and PDGFRβ in combination, significantly decreased tumor cell migration in Boyden chamber assays and suppressed cell migration in scratch wound assays. Somewhat surprisingly, concomitant knockdown of PDGFRα and PDGFRβ resulted in a modest increase in cell proliferation and a decrease in apoptosis. Conclusion During IGF-IR independence, PDGFRs are upregulated and function to enhance tumor cell motility. These results demonstrate a novel interaction between the IGF-IR and PDGFRs and highlight an important, therapeutically relevant pathway, for tumor cell migration and invasion.

  12. Overactivation of phospholipase C-gamma1 renders platelet-derived growth factor beta-receptor-expressing cells independent of the phosphatidylinositol 3-kinase pathway for chemotaxis

    DEFF Research Database (Denmark)

    Rönnstrand, L; Siegbahn, A; Rorsman, C

    1999-01-01

    ., Siegbahn, A. , Rorsman, C., Engström, U., Wernstedt, C., Heldin, C.-H., and Rönnstrand, L. (1996) EMBO J. 15, 5299-5313). Here we show that the increased chemotaxis correlates with increased activation of phospholipase C-gamma1 (PLC-gamma1), measured as inositol-1,4, 5-trisphosphate release. By two......-dimensional phosphopeptide mapping, the increase in phosphorylation of PLC-gamma1 was shown not to be selective for any site, rather a general increase in phosphorylation of PLC-gamma1 was seen. Specific inhibitors of protein kinase C, bisindolylmaleimide (GF109203X), and phosphatidylinositol 3-kinase (PI3-kinase), LY294002......, did not affect the activation of PLC-gamma1. To assess whether increased activation of PLC-gamma1 is the cause of the hyperchemotactic behavior of the Y934F mutant cell line, we constructed cell lines expressing either wild-type or a catalytically compromised version of PLC-gamma1 under a tetracycline...

  13. Vertical ridge augmentation using an equine bone and collagen block infused with recombinant human platelet-derived growth factor-BB: a randomized single-masked histologic study in non-human primates.

    Science.gov (United States)

    Nevins, Myron; Al Hezaimi, Khalid; Schupbach, Peter; Karimbux, Nadeem; Kim, David M

    2012-07-01

    This study tests the effectiveness of hydroxyapatite and collagen bone blocks of equine origin (eHAC), infused with recombinant human platelet-derived growth factor-BB (rhPDGF-BB), to augment localized posterior mandibular defects in non-human primates (Papio hamadryas). Bilateral critical-sized defects simulating severe atrophy were created at the time of the posterior teeth extraction. Test and control blocks (without growth factor) were randomly grafted into the respective sites in each non-human primate. All sites exhibited vertical ridge augmentation, with physiologic hard- and soft-tissue integration of the blocks when clinical and histologic examinations were done at 4 months after the vertical ridge augmentation procedure. There was a clear, although non-significant, tendency to increased regeneration in the test sites. As in the first two preclinical studies in this series using canines, experimental eHAC blocks infused with rhPDGF-BB proved to be a predictable and technically viable method to predictably regenerate bone and soft tissue in critical-sized defects. This investigation supplies additional evidence that eHAC blocks infused with rhPDGF-BB growth factor is a predictable and technically feasible option for vertical augmentation of severely resorbed ridges.

  14. Injury induces in vivo expression of platelet-derived growth factor (PDGF) and PDGF receptor mRNAs in skin epithelial cells and PDGF mRNA in connective tissue fibroblasts

    International Nuclear Information System (INIS)

    Antoniades, H.N.; Galanopoulos, T.; Neville-Golden, J.; Kiritsy, C.P.; Lynch, S.E.

    1991-01-01

    Platelet-derived growth factor (PDGF) stimulates many of the processes important in tissue repair, including proliferation of fibroblasts and synthesis of extracellular matrices. In this study, the authors have demonstrated with in situ hydridization and immunocytochemistry the reversible expression of 3-sis/PDGF-2 and PDGF receptor (PDGF-R) b mRNAs and their respective protein products in epithelial cells and fibroblasts following cutaneous injury in pigs. Epithelial cells in control, unwounded skin did not express c-sis and PDGF-R mRNAs, and fibroblasts expressed only PDGF-R mRNA. The expression levels in the injured site were correlated with the stage of tissue repair, being highest during the initial stages of the repair process and declining at the time of complete re-epithelialization and tissue remodeling. These studies provide a mulecular basis for understanding the mechanisms contributing to normal tissue repair. They suggest the possibility that a defect in these mechanisms may be associated with defective wound healing. It is also conceivable that chronic injury may induce irreversible gene expression leading to pathologic, unregulated cell growth

  15. cDNA for the human β2-adrenergic receptor: a protein with multiple membrane-spanning domains and encoded by a gene whose chromosomal location is shared with that of the receptor for platelet-derived growth factor

    International Nuclear Information System (INIS)

    Kobilka, B.K.; Dixon, R.A.F.; Frielle, T.

    1987-01-01

    The authors have isolated and sequenced a cDNA encoding the human β 2 -adrenergic receptor. The deduced amino acid sequence (413 residues) is that of a protein containing seven clusters of hydrophobic amino acids suggestive of membrane-spanning domains. While the protein is 87% identical overall with the previously cloned hamster β 2 -adrenergic receptor, the most highly conserved regions are the putative transmembrane helices (95% identical) and cytoplasmic loops (93% identical), suggesting that these regions of the molecule harbor important functional domains. Several of the transmembrane helices also share lesser degrees of identity with comparable regions of select members of the opsin family of visual pigments. They have localized the gene for the β 2 -adrenergic receptor to q31-q32 on chromosome 5. This is the same position recently determined for the gene encoding the receptor for platelet-derived growth factor and is adjacent to that for the FMS protooncogene, which encodes the receptor for the macrophage colony-stimulating factor

  16. The C-terminal SH2 domain of p85 accounts for the high affinity and specificity of the binding of phosphatidylinositol 3-kinase to phosphorylated platelet-derived growth factor beta receptor.

    Science.gov (United States)

    Klippel, A; Escobedo, J A; Fantl, W J; Williams, L T

    1992-01-01

    Upon stimulation by its ligand, the platelet-derived growth factor (PDGF) receptor associates with the 85-kDa subunit of phosphatidylinositol (PI) 3-kinase. The 85-kDa protein (p85) contains two Src homology 2 (SH2) domains and one SH3 domain. To define the part of p85 that interacts with the PDGF receptor, a series of truncated p85 mutants was analyzed for association with immobilized PDGF receptor in vitro. We found that a fragment of p85 that contains a single Src homology domain, the C-terminal SH2 domain (SH2-C), was sufficient for directing the high-affinity interaction with the receptor. Half-maximal binding of SH2-C to the receptor was observed at an SH2-C concentration of 0.06 nM. SH2-C, like full-length p85, was able to distinguish between wild-type PDGF receptor and a mutant receptor lacking the PI 3-kinase binding site. An excess of SH2-C blocked binding of full-length p85 and PI 3-kinase to the receptor but did not interfere with the binding of two other SH2-containing proteins, phospholipase C-gamma and GTPase-activating protein. These results demonstrate that a region of p85 containing a single SH2 domain accounts both for the high affinity and specificity of binding of PI 3-kinase to the PDGF receptor. Images PMID:1312663

  17. Analysis of receptor signaling pathways by mass spectrometry: identification of vav-2 as a substrate of the epidermal and platelet-derived growth factor receptors

    DEFF Research Database (Denmark)

    Pandey, A; Podtelejnikov, A V; Blagoev, B

    2000-01-01

    Oligomerization of receptor protein tyrosine kinases such as the epidermal growth factor receptor (EGFR) by their cognate ligands leads to activation of the receptor. Transphosphorylation of the receptor subunits is followed by the recruitment of signaling molecules containing src homology 2 (SH2...

  18. Overexpression of microRNA-375 impedes platelet-derived growth factor-induced proliferation and migration of human fetal airway smooth muscle cells by targeting Janus kinase 2.

    Science.gov (United States)

    Ji, Yamei; Yang, Xin; Su, Huixia

    2018-02-01

    The abnormal proliferation and migration of airway smooth muscle (ASM) cells play a critical role in airway remodeling during the development of asthma. MicroRNAs (miRNAs) have emerged as critical regulators of ASM cell proliferation and migration in airway remodeling. In this study, we aimed to investigate the potential role of miR-375 in the regulation of platelet-derived growth factor (PDGF)-induced fetal ASM cell proliferation and migration. Our results showed that miR-375 expression was significantly decreased in fetal ASM cells that were treated with PDGF. Functional data showed that overexpression of miR-375 inhibited the proliferation and migration of fetal ASM cells, whereas inhibition of miR-375 enhanced the proliferation and migration of fetal ASM cells. The results of bioinformatics analysis and a dual-luciferase reporter assay showed that miR-375 binds directly to the 3'-untranslated region of Janus kinase 2 (JAK2). Further data confirmed that miR-375 negatively regulates the expression of JAK2 in fetal ASM cells. Moreover, miR-375 also impeded the PDGF-induced activation of signal transducer and activator of transcription 3 (STAT3) in fetal ASM cells. However, restoration of JAK2 expression partially reversed the inhibitory effect of miR-375 on fetal ASM cell proliferation and migration. Overall, our results demonstrate that miR-375 inhibits fetal ASM cell proliferation and migration by targeting JAK2/STAT3 signaling. Our study provides a potential therapeutic target for the development of novel treatment strategies for pediatric asthma. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. MicroRNA-20b-5p inhibits platelet-derived growth factor-induced proliferation of human fetal airway smooth muscle cells by targeting signal transducer and activator of transcription 3.

    Science.gov (United States)

    Tang, Jin; Luo, Lingying

    2018-06-01

    Pediatric asthma is still a health threat to the pediatric population in recent years. The airway remodeling induced by abnormal airway smooth muscle (ASM) cell proliferation is an important cause of asthma. MicroRNAs (miRNAs) are important regulators of ASM cell proliferation. Numerous studies have reported that miR-20b-5p is a critical regulator for cell proliferation. However, whether miR-20b-5p is involved in regulating ASM cell proliferation remains unknown. In this study, we aimed to investigate the potential role of miR-20b-5p in regulating the proliferation of fetal ASM cell induced by platelet-derived growth factor (PDGF). Here, we showed that miR-20b-5p was significantly decreased in fetal ASM cells treated with PDGF. Biological experiments showed that the overexpression of miR-20b-5p inhibited the proliferation while miR-20b-5p inhibition markedly promoted the proliferation of fetal ASM cells. Bioinformatics analysis and luciferase reporter assay showed that miR-20b-5p directly targeted the 3'-UTR of signal transducer and activator of transcription 3 (STAT3). Further data showed that miR-20b-5p negatively regulated the expression of STAT3 in fetal ASM cells. Moreover, miR-20b-5p regulates the transcriptional activity of STAT3 in fetal ASM cells. Overexpression of STAT3 reversed the inhibitory effect of miR-20b-5p overexpression on fetal ASM cell proliferation while the knockdown of STAT3 abrogated the promoted effect of miR-20b-5p inhibition on fetal ASM cell proliferation. Overall, our results show that miR-20b-5p impedes PDGF-induced proliferation of fetal ASM cells through targeting STAT3. Our study suggests that miR-20b-5p may play an important role in airway remodeling during asthma and suggests that miR-20b-5p may serve as a potential therapeutic target for pediatric asthma. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  20. Platelet-Derived Microvesicles in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Maria T. K. Zaldivia

    2017-11-01

    Full Text Available Microvesicles (MVs circulating in the blood are small vesicles (100–1,000 nm in diameter derived from membrane blebs of cells such as activated platelets, endothelial cells, and leukocytes. A growing body of evidence now supports the concept that platelet-derived microvesicles (PMVs, the most abundant MVs in the circulation, are important regulators of hemostasis, inflammation, and angiogenesis. Compared with healthy individuals, a large increase of circulating PMVs has been observed, particularly in patients with cardiovascular diseases. As observed in MVs from other parent cells, PMVs exert their biological effects in multiple ways, such as triggering various intercellular signaling cascades and by participating in transcellular communication by the transfer of their “cargo” of cytoplasmic components and surface receptors to other cell types. This review describes our current understanding of the potential role of PMVs in mediating hemostasis, inflammation, and angiogenesis and their consequences on the pathogenesis of cardiovascular diseases, such as atherosclerosis, myocardial infarction, and venous thrombosis. Furthermore, new developments of the therapeutic potential of PMVs for the treatment of cardiovascular diseases will be discussed.

  1. The influence of platelet- derived products on angiogenesis and tissue repair: a concise update

    Directory of Open Access Journals (Sweden)

    Constanza E Martínez

    2015-10-01

    Full Text Available Platelet degranulation allows the release of a large amount of soluble mediators, is an essential step for wound healing initiation, and stimulates clotting and angiogenesis. The latter process is one of the most critical biological events observed during tissue repair,increasing the growth of blood vessels in the maturing wound. Angiogenesis requires the action of a variety of growth factors that act in an appropriate physiological ratio to assure functional blood vessel restoration. Platelets release main regulators of angiogenesis: Vascular Endothelial Growth Factors (VEGFs, basic fibroblast growth factor (FGF-2, and Platelet derived growth factors (PDGFs, among others. In order to stimulate tissue repair, platelet derived fractions have been used as an autologous source of growth factors and biomolecules, namely Platelet Rich Plasma (PRP, Platelet Poor Plasma (PPP and Platelet Rich Fibrin(PRF. The continuous release of these growth factors has been proposed to promote angiogenesis both in vitro and in vivo. Considering the existence of clinical trials currently evaluating the efficacy of autologous PRP, the present review analyses fundamental questions regarding the putative role of platelet derived fractions as regulators of angiogenesis and evaluates the possible clinical implications of these formulations.

  2. Incorporation of Human-Platelet-Derived Growth Factor-BB Encapsulated Poly(lactic-co-glycolic acid) Microspheres into 3D CORAGRAF Enhances Osteogenic Differentiation of Mesenchymal Stromal Cells

    DEFF Research Database (Denmark)

    Mohan, Saktiswaren; Raghavendran, Hanumantharao Balaji; Karunanithi, Puvanan

    2017-01-01

    Tissue engineering aims to generate or facilitate regrowth or healing of damaged tissues by applying a combination of biomaterials, cells, and bioactive signaling molecules. In this regard, growth factors clearly play important roles in regulating cellular fate. However, uncontrolled release...... was noted to support rapid cell expansion and differentiation of stromal cells into osteogenic cells in vitro for bone tissue engineering applications....

  3. Association assessment of platelet derived growth factor B gene ...

    African Journals Online (AJOL)

    Shayesteh Rezayani

    2017-04-21

    Apr 21, 2017 ... susceptibility and environmental risk factors and their interactions. [1] and starts .... Germany) as internal control, and 30 lM of each specific primer. (Eurofins .... thank the Arya Tina Gene company for recruiting study subjects.

  4. Platelet-derived growth factor mediates interleukin-13-induced ...

    Indian Academy of Sciences (India)

    2014-07-01

    4), September 2014, 693–700, * Indian Academy of Sciences. 693. Keywords. ... ence, France) were dissolved in 100% dimethyl sulfox- ide (DMSO) at ..... of China (81070045), the Key Clinical Project for Affiliated. Hospital of ...

  5. Parallel rendering

    Science.gov (United States)

    Crockett, Thomas W.

    1995-01-01

    This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

  6. Three-dimensional rendering of otolith growth using phase contrast synchrotron tomography.

    Science.gov (United States)

    Mapp, J J I; Fisher, M H; Atwood, R C; Bell, G D; Greco, M K; Songer, S; Hunter, E

    2016-05-01

    A three-dimensional computer reconstruction of a plaice Pleuronectes platessa otolith is presented from data acquired by the Diamond Light synchrotron, beamline I12, X-ray source, a high energy (53-150 keV) source particularly well suited to the study of dense objects. The data allowed non-destructive rendering of otolith structure, and for the first time allows otolith annuli (internal ring structures) to be analysed in X-ray tomographic images. © 2016 The Fisheries Society of the British Isles.

  7. Effect of cigarette smoke on monocyte procoagulant activity: Focus on platelet-derived brain-derived neurotrophic factor (BDNF).

    Science.gov (United States)

    Amadio, Patrizia; Baldassarre, Damiano; Sandrini, Leonardo; Weksler, Babette B; Tremoli, Elena; Barbieri, Silvia S

    2017-01-01

    Cigarette smoke (CS) activates platelets, promotes vascular dysfunction, and enhances Tissue Factor (TF) expression in blood monocytes favoring pro-thrombotic states. Brain-derived neurotrophic factor (BDNF), a member of the family of neurotrophins involved in survival, growth, and maturation of neurons, is released by activated platelets (APLTs) and plays a role in the cardiovascular system. The effect of CS on circulating levels of BDNF is controversial and the function of circulating BDNF in atherothrombosis is not fully understood. Here, we have shown that human platelets, treated with an aqueous extract of CS (CSE), released BDNF in a dose-dependent manner. In addition, incubation of human monocytes with BDNF or with the supernatant of platelets activated with CSE increased TF activity by a Tropomyosin receptor kinase B (TrkB)-dependent mechanism. Finally, comparing serum and plasma samples of 12 male never smokers (NS) and 29 male active smokers (AS) we observed a significant increase in microparticle-associated TF activity (MP-TF) as well as BDNF in AS, while in serum, BDNF behaved oppositely. Taken together these findings suggest that platelet-derived BDNF is involved in the regulation of TF activity and that CS plays a role in this pathway by favoring a pro-atherothrombotic state.

  8. Platelet-Derived MRP-14 Induces Monocyte Activation in Patients With Symptomatic Peripheral Artery Disease.

    Science.gov (United States)

    Dann, Rebecca; Hadi, Tarik; Montenont, Emilie; Boytard, Ludovic; Alebrahim, Dornaszadat; Feinstein, Jordyn; Allen, Nicole; Simon, Russell; Barone, Krista; Uryu, Kunihiro; Guo, Yu; Rockman, Caron; Ramkhelawon, Bhama; Berger, Jeffrey S

    2018-01-02

    Peripheral artery disease (PAD), a diffuse manifestation of atherothrombosis, is a major cardiovascular threat. Although platelets are primary mediators of atherothrombosis, their role in the pathogenesis of PAD remains unclear. The authors sought to investigate the role of platelets in a cohort of symptomatic PAD. The authors profiled platelet activity, mRNA, and effector roles in patients with symptomatic PAD and in healthy controls. Patients with PAD and carotid artery stenosis were recruited into ongoing studies (NCT02106429 and NCT01897103) investigating platelet activity, platelet RNA, and cardiovascular disease. Platelet RNA sequence profiling mapped a robust up-regulation of myeloid-related protein (MRP)-14 mRNA, a potent calcium binding protein heterodimer, in PAD. Circulating activated platelets were enriched with MRP-14 protein, which augmented the expression of the adhesion mediator, P-selectin, thereby promoting monocyte-platelet aggregates. Electron microscopy confirmed the firm interaction of platelets with monocytes in vitro and colocalization of macrophages with MRP-14 confirmed their cross talk in atherosclerotic manifestations of PAD in vivo. Platelet-derived MRP-14 was channeled to monocytes, thereby fueling their expression of key PAD lesional hallmarks and increasing their directed locomotion, which were both suppressed in the presence of antibody-mediated blockade. Circulating MRP-14 was heightened in the setting of PAD, significantly correlated with PAD severity, and was associated with incident limb events. The authors identified a heightened platelet activity profile and unraveled a novel immunomodulatory effector role of platelet-derived MRP-14 in reprograming monocyte activation in symptomatic PAD. (Platelet Activity in Vascular Surgery and Cardiovascular Events [PACE]; NCT02106429; and Platelet Activity in Vascular Surgery for Thrombosis and Bleeding [PIVOTAL]; NCT01897103). Copyright © 2018 American College of Cardiology Foundation

  9. The Role of Platelet-Derived Growth Factor C and Its Splice Variant in Breast Cancer

    Science.gov (United States)

    2012-02-01

    epithelial-mesenchymal transition leading instead to apoptosis (8). Furthermore, inhibition of PDGFR signaling by the PDGFR inhibitor STI571...PDGFRs are expressed in many different cell types including endothelial, epithelial and neural cells and are necessary for embryological development (as

  10. Graves’ Ophthalmopathy: A Comprehensive Role For Platelet-Derived Growth Factors

    NARCIS (Netherlands)

    L. van Steensel (Leendert)

    2012-01-01

    textabstractAutoimmune thyroid disorders include Graves’ disease (GD), which leads to hyperthyroidism, and Hashimoto’s thyroiditis, which leads to hypothyroidism. The incidence of autoimmune hypothyroidism is around five times higher than the incidence of autoimmune hyperthyroidism, but together

  11. Platelet-derived microparticles regulates thrombin generation via phophatidylserine in abdominal sepsis.

    Science.gov (United States)

    Wang, Yongzhi; Zhang, Su; Luo, Lingtao; Norström, Eva; Braun, Oscar Ö; Mörgelin, Matthias; Thorlacius, Henrik

    2018-02-01

    Sepsis is associated with dysfunctional coagulation. Recent data suggest that platelets play a role in sepsis by promoting neutrophil accumulation. Herein, we show that cecal ligation and puncture (CLP) triggered systemic inflammation, which is characterized by formation of IL-6 and CXC chemokines as well as neutrophil accumulation in the lung. Platelet depletion decreased neutrophil accumulation, IL-6, and CXC chemokines formation in septic lungs. Depletion of platelets increased peak thrombin formation and total thrombin generation (TG) in plasma from septic animals. CLP elevated circulating levels of platelet-derived microparticles (PMPs). In vitro generated PMPs were a potent inducer of TG. Interestingly, in vitro wild-type recombinant annexin V abolished PMP-induced thrombin formation whereas a mutant annexin V protein, which does not bind to phosphatidylserine (PS), had no effect. Administration of wild-type, but not mutant annexin V, significantly inhibited thrombin formation in septic animals. Moreover, CLP-induced formation of thrombin-antithrombin complexes were reduced in platelet-depleted mice and in animals pretreated with annexin V. PMP-induced TG attenuated in FXII- and FVII-deficient plasma. These findings suggest that sepsis-induced TG is dependent on platelets. Moreover, PMPs formed in sepsis are a potent inducer of TG via PS exposure, and activation of both the intrinsic and extrinsic pathway of coagulation. In conclusion, these observations suggest that PMPs and PS play an important role in dysfunctional coagulation in abdominal sepsis. © 2017 Wiley Periodicals, Inc.

  12. Vermiculite's strong buffer capacity renders it unsuitable for studies of acidity on soybean (Glycine max L.) nodulation and growth.

    Science.gov (United States)

    Indrasumunar, Arief; Gresshoff, Peter M

    2013-11-14

    Vermiculite is the most common soil-free growing substrate used for plants in horticultural and scientific studies due to its high water holding capacity. However, some studies are not suitable to be conducted in it. The described experiments aimed to test the suitability of vermiculite to study the effect of acidity on nodulation and growth of soybean (Glycine max L.). Two different nutrient solutions (Broughton & Dilworth, and modified Herridge nutrient solutions) with or without MES buffer addition were used to irrigate soybean grown on vermiculite growth substrates. The pH of nutrient solutions was adjusted to either pH 4.0 or 7.0 prior its use. The nodulation and vegetative growth of soybean plants were assessed at 3 and 4 weeks after inoculation. The unsuitability of presumably inert vermiculite as a physical plant growth substrate for studying the effects of acidity on soybean nodulation and plant growth was illustrated. Nodulation and growth of soybean grown in vermiculite were not affected by irrigation with pH-adjusted nutrient solution either at pH 4.0 or 7.0. This was reasonably caused by the ability of vermiculite to neutralise (buffer) the pH of the supplied nutrient solution (pH 2.0-7.0). Due to its buffering capacity, vermiculite cannot be used as growth support to study the effect of acidity on nodulation and plant growth.

  13. Platelet-Derived Short-Chain Polyphosphates Enhance the Inactivation of Tissue Factor Pathway Inhibitor by Activated Coagulation Factor XI.

    Directory of Open Access Journals (Sweden)

    Cristina Puy

    Full Text Available Factor (F XI supports both normal human hemostasis and pathological thrombosis. Activated FXI (FXIa promotes thrombin generation by enzymatic activation of FXI, FIX, FX, and FV, and inactivation of alpha tissue factor pathway inhibitor (TFPIα, in vitro. Some of these reactions are now known to be enhanced by short-chain polyphosphates (SCP derived from activated platelets. These SCPs act as a cofactor for the activation of FXI and FV by thrombin and FXIa, respectively. Since SCPs have been shown to inhibit the anticoagulant function of TFPIα, we herein investigated whether SCPs could serve as cofactors for the proteolytic inactivation of TFPIα by FXIa, further promoting the efficiency of the extrinsic pathway of coagulation to generate thrombin.Purified soluble SCP was prepared by size-fractionation of sodium polyphosphate. TFPIα proteolysis was analyzed by western blot. TFPIα activity was measured as inhibition of FX activation and activity in coagulation and chromogenic assays. SCPs significantly accelerated the rate of inactivation of TFPIα by FXIa in both purified systems and in recalcified plasma. Moreover, platelet-derived SCP accelerated the rate of inactivation of platelet-derived TFPIα by FXIa. TFPIα activity was not affected by SCP in recalcified FXI-depleted plasma.Our data suggest that SCP is a cofactor for TFPIα inactivation by FXIa, thus, expanding the range of hemostatic FXIa substrates that may be affected by the cofactor functions of platelet-derived SCP.

  14. Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles.

    Science.gov (United States)

    Rank, A; Nieuwland, R; Liebhardt, S; Iberer, M; Grützner, S; Toth, B; Pihusch, R

    2011-02-01

    Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). MP were double stained with annexin V and CD61 (platelet-derived MP; PMP), P-selectin or CD63 (MP from activated platelets) and CD144 plus E-selectin (endothelial cell-derived MP; EMP) and detected by flow cytometry in platelet donors (n=36) and apheresis PC (n=11; Trima™). PC contained MP, mainly from resting platelets [93% (90-95)], and minor fractions of PMP from activated platelets [P-selectin(+) or CD63(+); 4·8% (3·2-7·7) and 2·6% (2·0-4·0)]. Compared to donors, levels of annexin V+ MP, PMP, P-selectin(+) and CD63(+) MP were 1·7-, 2·3-, 8·6- and 3·1-fold higher in PC (all P<0·05). During storage (1-5 days), levels of annexin V+ MP and PMP did not increase, although small increases in the fraction of P-selectin(+) or CD63(+) MP occurred (both P<0·05). PC also contained EMP, which were 2·6- to 3·7-fold enriched in PC compared to donors (P<0·05). Transfusion of apheresis PC also results in transfusion of HLA-carrying PMP and EMP. This might counteract the aim of reducing transfused HLA load by leucodepletion. The increases in PMP exposing P-selectin or CD63 reflect mild platelet activation during storage. We conclude that in leucodepleted platelet apheresis using fluidized particle bed technology, MP are harvested mainly from the donor by apheresis. Improvement in apheresis technology might reduce MP load. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.

  15. Preservation of Biological Activity of Plasma and Platelet-Derived Eye Drops After Their Different Time and Temperature Conditions of Storage.

    Science.gov (United States)

    Anitua, Eduardo; de la Fuente, María; Riestra, Ana; Merayo-Lloves, Jesús; Muruzábal, Francisco; Orive, Gorka

    2015-09-01

    To analyze whether plasma rich in growth factors (PRGF) eye drops preserve their biological characteristics and activity after storage for 3 and 6 months at -20°C, at 4°C, and at room temperature for 72 hours, compared with fresh samples (t0). Blood from 6 healthy donors was harvested and centrifuged to obtain PRGF free of leukocytes. Resulting PRGF eye drops were stored for 3 and 6 months at -20°C. At each time, 2 aliquots were maintained at room temperature or at 4°C for 72 hours. Platelet-derived growth factor-AB, transforming growth factor-β1, vascular endothelial growth factor, epidermal growth factor, insulin-like growth factor-1, angiopoietin-1, and thrombospondin-1 were quantified at each time and temperature of storage. Also, the effect of PRGF eye drops on proliferation of primary human keratocytes was evaluated. All the analyzed growth factor levels remained constant at each time and storage condition. No differences were observed in the proliferative activity of keratocytes after treatment with PRGF eye drops at any studied time or temperature. Finally, there was no microbial contamination in any of the PRGF eye drops. The preservation of the PRGF eye drops at -20°C for up to 3 and 6 months does not mean reduction of the main growth factors and proteins implicated in ocular surface wound healing. Eye drop characteristics and in vitro biological activity were not affected by their usage and conservation for 72 hours at 4°C or at room temperature.

  16. Video-based rendering

    CERN Document Server

    Magnor, Marcus A

    2005-01-01

    Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

  17. Rendering of Gemstones

    OpenAIRE

    Krtek, Lukáš

    2012-01-01

    The distinctive appearance of gemstones is caused by the way light reflects and refracts multiple times inside of them. The goal of this thesis is to design and implement an application for photorealistic rendering of gems. The most important effects we aim for are realistic dispersion of light and refractive caustics. For rendering we use well-known algorithm of path tracing with an experimental modification for faster computation of caustic effects. In this thesis we also design and impleme...

  18. Platelet-derived stromal cell-derived factor-1 is required for the transformation of circulating monocytes into multipotential cells.

    Directory of Open Access Journals (Sweden)

    Noriyuki Seta

    Full Text Available BACKGROUND: We previously described a primitive cell population derived from human circulating CD14(+ monocytes, named monocyte-derived multipotential cells (MOMCs, which are capable of differentiating into mesenchymal and endothelial lineages. To generate MOMCs in vitro, monocytes are required to bind to fibronectin and be exposed to soluble factor(s derived from circulating CD14(- cells. The present study was conducted to identify factors that induce MOMC differentiation. METHODS: We cultured CD14(+ monocytes on fibronectin in the presence or absence of platelets, CD14(- peripheral blood mononuclear cells, platelet-conditioned medium, or candidate MOMC differentiation factors. The transformation of monocytes into MOMCs was assessed by the presence of spindle-shaped adherent cells, CD34 expression, and the potential to differentiate in vitro into mesenchymal and endothelial lineages. RESULTS: The presence of platelets or platelet-conditioned medium was required to generate MOMCs from monocytes. A screening of candidate platelet-derived soluble factors identified stromal cell-derived factor (SDF-1 as a requirement for generating MOMCs. Blocking an interaction between SDF-1 and its receptor CXCR4 inhibited MOMC generation, further confirming SDF-1's critical role in this process. Finally, circulating MOMC precursors were found to reside in the CD14(+CXCR4(high cell population. CONCLUSION: The interaction of SDF-1 with CXCR4 is essential for the transformation of circulating monocytes into MOMCs.

  19. Rendering the Topological Spines

    Energy Technology Data Exchange (ETDEWEB)

    Nieves-Rivera, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-05

    Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

  20. In situ expression of platelet-derived growth factor (PDGF-beta) during chronic rejection is abolished by retransplantation.

    Science.gov (United States)

    Yang, H C; McElroy, R J; Kreider, J W; Marshall, R L; Martinie, J B; Diamond, J

    1995-07-01

    We have shown that Fischer 344-->Lewis renal allografts (ALLO) develop chronic rejection which is not detected in Lewis-->Lewis isografts (ISO). The progression of chronic rejection in ALLO can be reversed by retransplantation (RE-TX) of kidneys from ALLO back into syngeneic Fischer 344 recipients. The purpose of this study was to assess the in situ expression of PDGF-beta, a cytokine associated with wound injury, in ISO, ALLO, and RE-TX. In situ PDGF-beta mRNA expression in kidney sections was assessed early (8 weeks) and late (16 weeks) during the development of chronic rejection. Kidneys from ALLO were transplanted back into syngeneic Fischer recipients at 12 weeks and evaluated for PDGF-beta expression 12 weeks later. Differences in glomerular staining were graded quantitatively on a minimum of 25 glomeruli per section with grade 0, no positive cells in the glomerulus; grade 1, 1 or 2 positive cells; grade 2, 3 or more positive cells in a segmental distribution; and grade 3, > 4 positive cells of moderate intensity in a diffuse distribution. According to this grading system, glomerular PDGF-beta mRNA expression in isografts (N = 6) at 8 and 16 weeks after transplantation was 0.09 +/- 0.03 and 0.2 +/- 0.04, respectively. In allografts (N = 6), PDGF-beta mRNA was significantly higher (P < .001) for the same time periods, 1.28 +/- 0.6 and 1.89 +/- 0.08, respectively. In situ expression of PDGF in retransplants (N = 6) at 24 weeks, 0.07 +/- 0.02, was significantly diminished (P < .001) at 24 weeks compared to allografts at 8 or 16 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Bacteria-induced release of white cell--and platelet-derived vascular endothelial growth factor in vitro

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Werther, K; Mynster, T

    2001-01-01

    of buffy-coat-depleted red cell (SAGM) blood were donated by healthy blood donors. Subsequently, half of every unit was leucocyte depleted by filtration, and all 32 half-units were stored under standard conditions for 35 days. Just after storage, and on days 7, 21 and 35 during storage, aliquots...

  2. Influence of a ras oncogene on platelet-derived growth factor (PDGF)-stimulated phosphoinositide hydrolysis in murine fibroblasts

    International Nuclear Information System (INIS)

    Parries, G.; Racker, E.

    1986-01-01

    The authors have examined the effects of transfection of rat-1 fibroblasts with the ras oncogene on the metabolism of phosphatidylinositol (PI). Incubation of [ 3 H]inositol-labeled rat-1 cells with PDGF resulted in a 2- to 3-fold increase in [ 3 H]IP3 levels within 90 s. In the presence of 25 mM Li+, [ 3 H]IP1 levels were increased 8-fold after 30 min. In contrast, incubation of ras-transfected fibroblasts (EJ-2 line) with PDGF had little or no effect on the level of either [ 3 H]IP3 or [ 3 H]IP1. Similar stimulations by PDGF were observed in NIH 3T3 cells, but not in Kirsten virus-transformed or Harvey ras-transfected cell lines. On the other hand, NIH 3T3 cells transfected with v-src responded to PDGF by stimulation of PI turnover similar to the parent cell line. In NIH 3T3 cells transfected with an expression vector containing the v-Ha-ras gene under transcriptional control of the glucocorticoid-inducible mouse mammary tumor virus promoter, the PDGF stimulation of [ 3 H]inositol incorporation into PI was reduced from 10-fold in the absence of dexamethasone to 1.8-fold when the cells were pretreated for 26 h with 2 μM dexamethasone. In the parental 3T3 cells PDGF stimulation was reduced by about 40% in the presence of dexamethasone. In the absence of PDGF the rate of PI turnover (i.e., the kinetics of [ 3 H]IP1 accumulation in the presence of Li+) in EJ-2 cells was similar to that in rat-1 cells. Thus, in the presence of PDGF, the rate of PI turnover in rat-1 cells was several fold higher than in the transfected cells. These results suggest that the ras gene product (p21) may exert an inhibitory effect on PDGF-stimulated phosphoinositide metabolism

  3. Development of a NanoBioAnalytical platform for "on-chip" qualification and quantification of platelet-derived microparticles.

    Science.gov (United States)

    Obeid, Sameh; Ceroi, Adam; Mourey, Guillaume; Saas, Philippe; Elie-Caille, Celine; Boireau, Wilfrid

    2017-07-15

    Blood microparticles (MPs) are small membrane vesicles (50-1000nm), derived from different cell types. They are known to play important roles in various biological processes and also recognized as potential biomarkers of various health disorders. Different methods are currently used for the detection and characterization of MPs, but none of these methods is capable to quantify and qualify total MPs at the same time, hence, there is a need to develop a new approach for simultaneous detection, characterization and quantification of microparticles. Here we show the potential of surface plasmon resonance (SPR) method coupled to atomic force microscopy (AFM) to quantify and qualify platelet-derived microparticles (PMPs), on the whole nano-to micro-meter scale. The different subpopulations of microparticles could be determined via their capture onto the surface using specific ligands. In order to verify the correlation between the capture level and the microparticles concentration in solution, two calibration standards were used: Virus-Like Particles (VLPs) and synthetic beads with a mean diameter of 53nm and 920nm respectively. The AFM analysis of the biochip surface allowed metrological analysis of captured PMPs and revealed that more than 95% of PMPs were smaller than 300nm. Our results suggest that our NanoBioAnalytical platform, combining SPR and AFM, is a suitable method for a sensitive, reproducible, label-free characterization and quantification of MPs over a wide concentration range (≈10 7 to 10 12 particles/mL; with a limit of detection (LOD) in the lowest ng/µL range) which matches with their typical concentrations in blood. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. High Fidelity Haptic Rendering

    CERN Document Server

    Otaduy, Miguel A

    2006-01-01

    The human haptic system, among all senses, provides unique and bidirectional communication between humans and their physical environment. Yet, to date, most human-computer interactive systems have focused primarily on the graphical rendering of visual information and, to a lesser extent, on the display of auditory information. Extending the frontier of visual computing, haptic interfaces, or force feedback devices, have the potential to increase the quality of human-computer interaction by accommodating the sense of touch. They provide an attractive augmentation to visual display and enhance t

  5. ARE: Ada Rendering Engine

    Directory of Open Access Journals (Sweden)

    Stefano Penge

    2009-10-01

    Full Text Available E' ormai pratica diffusa, nello sviluppo di applicazioni web, l'utilizzo di template e di potenti template engine per automatizzare la generazione dei contenuti da presentare all'utente. Tuttavia a volte la potenza di tali engine è€ ottenuta mescolando logica e interfaccia, introducendo linguaggi diversi da quelli di descrizione della pagina, o addirittura inventando nuovi linguaggi dedicati.ARE (ADA Rendering Engine è€ pensato per gestire l'intero flusso di creazione del contenuto HTML/XHTML dinamico, la selezione del corretto template, CSS, JavaScript e la produzione dell'output separando completamente logica e interfaccia. I templates utilizzati sono puro HTML senza parti in altri linguaggi, e possono quindi essere gestiti e visualizzati autonomamente. Il codice HTML generato è€ uniforme e parametrizzato.E' composto da due moduli, CORE (Common Output Rendering Engine e ALE (ADA Layout Engine.Il primo (CORE viene utilizzato per la generazione OO degli elementi del DOM ed è pensato per aiutare lo sviluppatore nella produzione di codice valido rispetto al DTD utilizzato. CORE genera automaticamente gli elementi del DOM in base al DTD impostato nella configurazioneIl secondo (ALE viene utilizzato come template engine per selezionare automaticamente in base ad alcuni parametri (modulo, profilo utente, tipologia del nodo, del corso, preferenze di installazione il template HTML, i CSS e i file JavaScript appropriati. ALE permette di usare templates di default e microtemplates ricorsivi per semplificare il lavoro del grafico.I due moduli possono in ogni caso essere utilizzati indipendentemente l'uno dall'altro. E' possibile generare e renderizzare una pagina HTML utilizzando solo CORE oppure inviare gli oggetti CORE al template engine ALE che provvede a renderizzare la pagina HTML. Viceversa è possibile generare HTML senza utilizzare CORE ed inviarlo al template engine ALECORE è alla prima release ed è€ già utilizzato all

  6. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Michael [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  7. Transformative Rendering of Internet Resources

    Science.gov (United States)

    2012-10-01

    using either the Firefox or Google Chrome rendering engine. The rendering server then captures a screen shot of the page and creates code that positions...be compromised at web pages the hackers had built for that hacking competition to exploit that particular OS /browser configuration. During...of risk with no benefit. They include: - The rendering server is hosted on a Linux-based operating system ( OS ). The OS is much more secure than the

  8. Role of Platelet-derived Microvesicles as Crosstalk Mediators in Atherothrombosis and Future Pharmacology Targets: a Link between Inflammation, Atherosclerosis and Thrombosis

    Directory of Open Access Journals (Sweden)

    Lina Badimon

    2016-08-01

    Full Text Available Reports in the last decade have suggested that the role of platelets in atherosclerosis and its thrombotic complications may be mediated, in part, by local secretion of platelet-derived microvesicles (pMVs, small cell blebs released during the platelet activation process. MVs are the most abundant cell-derived microvesicle subtype in the circulation. High concentrations of circulating MVs have been reported in patients with atherosclerosis, acute vascular syndromes, and/or diabetes mellitus, suggesting a potential correlation between the quantity of microvesicles and the clinical severity of the atherosclerotic disease. pMVs are considered to be biomarkers of disease but new information indicates that pMVs are also involved in signaling functions. pMVs evoke or promote haemostatic and inflammatory responses, neovascularization, cell survival and apoptosis, processes involved in the pathophysiology of cardiovascular disease. This review is focused on the complex cross-talk between platelet-derived microvesicles, inflammatory cells and vascular elements and their relevance in the development of the atherosclerotic disease and its clinical outcomes, providing an updated state-of-the art of pMV involvement in atherothrombosis and pMV potential use as therapeutic agent influencing cardiovascular biomedicine in the future.

  9. Sketchy Rendering for Information Visualization

    NARCIS (Netherlands)

    Wood, Jo; Isenberg, Petra; Isenberg, Tobias; Dykes, Jason; Boukhelifa, Nadia; Slingsby, Aidan

    2012-01-01

    We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These

  10. T cell receptor (TCR-transgenic CD8 lymphocytes rendered insensitive to transforming growth factor beta (TGFβ signaling mediate superior tumor regression in an animal model of adoptive cell therapy

    Directory of Open Access Journals (Sweden)

    Quatromoni Jon G

    2012-06-01

    Full Text Available Abstract Tumor antigen-reactive T cells must enter into an immunosuppressive tumor microenvironment, continue to produce cytokine and deliver apoptotic death signals to affect tumor regression. Many tumors produce transforming growth factor beta (TGFβ, which inhibits T cell activation, proliferation and cytotoxicity. In a murine model of adoptive cell therapy, we demonstrate that transgenic Pmel-1 CD8 T cells, rendered insensitive to TGFβ by transduction with a TGFβ dominant negative receptor II (DN, were more effective in mediating regression of established B16 melanoma. Smaller numbers of DN Pmel-1 T cells effectively mediated tumor regression and retained the ability to produce interferon-γ in the tumor microenvironment. These results support efforts to incorporate this DN receptor in clinical trials of adoptive cell therapy for cancer.

  11. The important role of von Willebrand factor in platelet-derived FVIII gene therapy for murine hemophilia A in the presence of inhibitory antibodies.

    Science.gov (United States)

    Shi, Q; Schroeder, J A; Kuether, E L; Montgomery, R R

    2015-07-01

    Our previous studies have demonstrated that targeting FVIII expression to platelets results in FVIII storage together with von Willebrand factor (VWF) in platelet α-granules and that platelet-derived FVIII (2bF8) corrects the murine hemophilia A phenotype even in the presence of high-titer anti-FVIII inhibitory antibodies (inhibitors). To explore how VWF has an impact on platelet gene therapy for hemophilia A with inhibitors. 2bF8 transgenic mice in the FVIII(-/-) background (2bF8(tg+/-) F8(-/-) ) with varying VWF phenotypes were used in this study. Animals were analyzed by VWF ELISA, FVIII activity assay, Bethesda assay and tail clip survival test. Only 18% of 2bF8(tg+/-) F8(-/-) VWF(-/-) animals, in which VWF was deficient, survived the tail clip challenge with inhibitor titers of 3-8000 BU mL(-1) . In contrast, 82% of 2bF8(tg+/-) F8(-/-) VWF(+/+) mice, which had normal VWF levels, survived tail clipping with inhibitor titers of 10-50,000 BU mL(-1) . All 2bF8(tg+/-) F8(-/-) VWF(-/-) mice without inhibitors survived tail clipping and no VWF(-/-) F8(-/-) mice survived this challenge. Because VWF is synthesized by endothelial cells and megakaryocytes and is distributed in both plasma and platelets in peripheral blood, we further investigated the effect of each compartment of VWF on platelet-FVIII gene therapy for hemophilia A with inhibitors. In the presence of inhibitors, 42% of animals survived tail clipping in the group with plasma-VWF and 50% survived in the platelet-VWF group. VWF is essential for platelet gene therapy for hemophilia A with inhibitors. Both platelet-VWF and plasma-VWF are required for optimal platelet-derived FVIII gene therapy for hemophilia A in the presence of inhibitors. © 2015 International Society on Thrombosis and Haemostasis.

  12. Advanced Material Rendering in Blender

    Czech Academy of Sciences Publication Activity Database

    Hatka, Martin; Haindl, Michal

    2012-01-01

    Roč. 11, č. 2 (2012), s. 15-23 ISSN 1081-1451 R&D Projects: GA ČR GAP103/11/0335; GA ČR GA102/08/0593 Grant - others:CESNET(CZ) 387/2010; CESNET(CZ) 409/2011 Institutional support: RVO:67985556 Keywords : realistic material rendering * bidirectional texture function * Blender Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2013/RO/haindl-advanced material rendering in blender.pdf

  13. Sketchy Rendering for Information Visualization.

    Science.gov (United States)

    Wood, J; Isenberg, P; Isenberg, T; Dykes, J; Boukhelifa, N; Slingsby, A

    2012-12-01

    We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visualization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users' ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization design. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty.

  14. Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors

    Science.gov (United States)

    2013-01-01

    Introduction Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. Methods PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Results Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 106 to 1.9 × 106 platelets/μl). Platelets were highly purified, because only blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of

  15. GPU Pro advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2010-01-01

    This book covers essential tools and techniques for programming the graphics processing unit. Brought to you by Wolfgang Engel and the same team of editors who made the ShaderX series a success, this volume covers advanced rendering techniques, engine design, GPGPU techniques, related mathematical techniques, and game postmortems. A special emphasis is placed on handheld programming to account for the increased importance of graphics on mobile devices, especially the iPhone and iPod touch.Example programs and source code can be downloaded from the book's CRC Press web page. 

  16. Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors.

    Science.gov (United States)

    Amable, Paola Romina; Carias, Rosana Bizon Vieira; Teixeira, Marcus Vinicius Telles; da Cruz Pacheco, Italo; Corrêa do Amaral, Ronaldo José Farias; Granjeiro, José Mauro; Borojevic, Radovan

    2013-06-07

    Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 10(6) to 1.9 × 10(6) platelets/μl). Platelets were highly purified, because only platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of several growth factors, including platelet-derived growth factor and TGF. Our study resulted in a consistent PRP preparation method that yielded a cytokine and growth factor pool

  17. Absolute hypoxic exercise training enhances in vitro thrombin generation by increasing procoagulant platelet-derived microparticles under high shear stress in sedentary men.

    Science.gov (United States)

    Chen, Yu-Wen; Chen, Yi-Ching; Wang, Jong-Shyan

    2013-05-01

    HS (high shear) stress associated with artery stenosis facilitates TG (thrombin generation) by increasing the release of procoagulant PDMPs (platelet-derived microparticles). Physical exercise and hypoxia may paradoxically modulate vascular thrombotic risks. The aim of the present study was to investigate how exercise training with/without hypoxia affected TG mediated by PDMPs under physio-pathological shear flows. A total of 75 sedentary males were randomly divided into five groups (n=15 in each group): 21% O2 [NC (normoxic control)] or 15% O2 [HC (hypoxic control)] at rest or were trained at 50% of peak work rate under 21% O2 [NT (normoxic training)] or 15% O2 [HAT (hypoxic-absolute training)], or 50% of HR (heart rate) reserve under 15% O2 [HRT (hypoxic-relative training)] for 30 min/day, 5 days/week for 4 weeks. The PDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. Before the intervention, strenuous exercise markedly increased the PDMP count (14.8%) and TG rate (19.5%) in PDMP-rich plasma at 100 dynes/cm2 of shear stress (Pexercise. Conversely, HAT notably promoted the PDMP count (37.3%) and TG rate (38.9%) induced by HS (Pexercise. We conclude that both HRT and NT depress similarly HS-mediated TG during exercise, but HAT accelerates the prothrombotic response to vigorous exercise. These findings provide new insights into how exercise training under a hypoxic condition influences the risk of thrombosis associated with stenotic arteries.

  18. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun-Seok [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kang, Shin-il [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Yoo, Kyu-dong [Hazardous Substances Analysis Division, Gwangju Regional Food and Drug Administration, Gwangju (Korea, Republic of); Lee, Mi-Yea [Department of Nursing Kyungbok University, Pocheon (Korea, Republic of); Yoo, Hwan-Soo; Hong, Jin-Tae [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Shin, Hwa-Sup [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, Bokyung [Department of Physiology, Konkuk Medical School, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Yun, Yeo-Pyo, E-mail: ypyun@chungbuk.ac.kr [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of)

    2013-04-15

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway.

  19. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

    International Nuclear Information System (INIS)

    Park, Eun-Seok; Kang, Shin-il; Yoo, Kyu-dong; Lee, Mi-Yea; Yoo, Hwan-Soo; Hong, Jin-Tae; Shin, Hwa-Sup; Kim, Bokyung; Yun, Yeo-Pyo

    2013-01-01

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway

  20. Optimization of Platelet-Derived Growth Factor Receptor (PDGFR) Inhibitors for Duration of Action, as an Inhaled Therapy for Lung Remodeling in Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Shaw, Duncan E; Baig, Ferheen; Bruce, Ian; Chamoin, Sylvie; Collingwood, Stephen P; Cross, Sarah; Dayal, Satish; Drückes, Peter; Furet, Pascal; Furminger, Vikki; Haggart, Deborah; Hussey, Martin; Konstantinova, Irena; Loren, Jon C; Molteni, Valentina; Roberts, Sonia; Reilly, John; Saunders, Alex M; Stringer, Rowan; Sviridenko, Lilya; Thomas, Matthew; Thomson, Christopher G; Tomlins, Christine; Wen, Ben; Yeh, Vince; Pearce, Andrew C

    2016-09-08

    A series of potent PDGFR inhibitors has been identified. The series was optimized for duration of action in the lung. A novel kinase occupancy assay was used to directly measure target occupancy after i.t. dosing. Compound 25 shows 24 h occupancy of the PDGFR kinase domain, after a single i.t. dose and has efficacy at 0.03 mg/kg, in the rat moncrotaline model of pulmonary arterial hypertension. Examination of PK/PD data from the optimization effort has revealed in vitro:in vivo correlations which link duration of action in vivo with low permeability and high basicity and demonstrate that nonspecific binding to lung tissue increases with lipophilicity.

  1. Platelet-derived Growth-factor-releasing Aligned Collagen-nanoparticle Fibers Promote the Proliferation and Tenogenic Differentiation of Adipose-derived Stem Cells

    Science.gov (United States)

    2013-11-27

    among the most common ortho- pedic injuries to soldiers due to repeated exercise , heavy-duty work and battlefield injuries [1,2]. Tendon /ligament...longer, sustained effect on cells. This is highly desirable because tendons /ligaments tend to need a longer time to healing due to the lack of...C). A rat Achilles tendon can sustain a maximum force of 32 N. Depending on the outcome of mechanical evaluation, the aligned collagen fiber scaffold

  2. A Novel Roscovitine Derivative Potently Induces G(1)-Phase Arrest in Platelet-Derived Growth Factor-BB-Activated Vascular Smooth Muscle Cells

    Czech Academy of Sciences Publication Activity Database

    Sroka, I. M.; Heiss, E.H.; Havlíček, Libor; Totzke, F.; Aristei, Y.; Pechan, P.; Kubbutat, M.H.G.; Strnad, Miroslav; Dirsch, V.M.

    2010-01-01

    Roč. 77, č. 2 (2010), s. 255-261 ISSN 0026-895X R&D Projects: GA ČR GA301/08/1649 Grant - others:_(XE) LSHB-CT-2004-503467 Institutional research plan: CEZ:AV0Z50380511 Keywords : CYCLIN-DEPENDENT KINASES * DRUG-ELUTING STENTS * CYC202 R-ROSCOVITINE Subject RIV: FD - Oncology ; Hematology Impact factor: 4.725, year: 2010

  3. Platelet-derived growth factor (PDGF) B-chain gene expression by activated blood monocytes precedes the expression of the PDGF A-chain gene

    International Nuclear Information System (INIS)

    Martinet, Y.; Jaffe, H.A.; Yamauchi, K.; Betsholtz, C.; Westermark, B.; Heldin, C.H.; Crystal, R.G.

    1987-01-01

    When activated, normal human blood monocytes are known to express the c-sis proto-oncogene coding for PDGF B-chain. Since normal human platelet PDGF molecules are dimers of A and B chains and platelets and monocytes are derived from the same marrow precursors, activated blood monocytes were simultaneously evaluated for their expression of PDGF A and B chain genes. Human blood monocytes were purified by adherence, cultured with or without activation by lipopolysaccharide and poly(A)+ RNA evaluated using Northern analysis and 32 P-labeled A-chain and B-chain (human c-sis) probes. Unstimulated blood monocytes did not express either A-chain or B-chain genes. In contrast, activated monocytes expressed a 4.2 kb mRNA B-chain transcript at 4 hr, but the B-chain mRNA levels declined significantly over the next 18 hr. In comparison, activated monocytes expressed very little A-chain mRNA at 4 hr, but at 12 hr 1.9, 2.3, and 2.8 kb transcripts were observed and persisted through 24 hr. Thus, activation of blood monocytes is followed by PDGF B-chain gene expression preceding PDGF A-chain gene expression, suggesting a difference in the regulation of the expression of the genes for these two chains by these cells

  4. Platelet-derived growth factor (PDGF) in oncogenesis: development of a vascular connective tissue stroma in xenotransplanted human melanoma producing PDGF-BB.

    OpenAIRE

    Forsberg, K; Valyi-Nagy, I; Heldin, C H; Herlyn, M; Westermark, B

    1993-01-01

    Human WM9 melanoma cells, previously shown to be devoid of PDGF expression, were stably transfected with a PDGF-B cDNA under the transcriptional control of a cytomegalovirus promoter. Northern blot analysis revealed high expression of an mRNA of the expected size in the PDGF-B-transfected cells. Synthesis and secretion of PDGF-BB was confirmed by immunoprecipitation. Furthermore, conditioned medium from PDGF-B-transfected cells contained a mitogenic activity for fibroblasts. For analysis of t...

  5. Platelet-derived growth factor B retention is essential for development of normal structure and function of conduit vessels and capillaries

    DEFF Research Database (Denmark)

    Nyström, Henrik C.; Lindblom, Per; Wickman, Anna

    2006-01-01

    . This outward eutrophic remodelling of the aorta was accompanied by endothelial dysfunction. RetKO showed decreased capillary density in skeletal muscle and signs of a defective delivery of capillary oxygen to skeletal muscle, as shown by a decreased physical performance. In RetKO mice, echocardiography...

  6. A Single-Center Pilot Prospective Study of Topical Application of Platelet-Derived Eye Drops for Patients with Ocular Chronic Graft-versus-Host Disease.

    Science.gov (United States)

    Zallio, Francesco; Mazzucco, Laura; Monaco, Federico; Astori, Maria Rosa; Passera, Roberto; Drago, Giovanna; Tamiazzo, Stefania; Rapetti, Manuela; Dolcino, Daniela; Guaschino, Roberto; Pini, Massimo; Ladetto, Marco

    2016-09-01

    Ocular involvement of chronic graft-versus-host disease (cGVHD) is a complication that occurs in up to 60% of patients after allogeneic hematopoietic stem cell transplantation. Conventional therapeutic options include medical and surgical procedures that are administered depending on the severity of the condition, but most of them have provided unsatisfactory results and, to date, there is no consensus about treatment. We considered that topical application of a platelet lysate, administered as eye drops, might be considered an alternative worthwhile of investigation to treat ocular surface disorders in patients suffering from cGVHD. Therefore, we conducted a single-center prospective pilot study to assess the efficacy and safety of using eye drops made from reconstituted lysed platelet concentrate. Twenty-six patients with ocular cGVHD were eligible for the study; all but 2 completed their scheduled 1-year treatment and complied with the hematologic and ophthalmic regimen. At their first assessment interviews, after 30 days of treatment, 91% of patients reported an improvement in their symptoms and for 32%, substantive objective differences were measured. Remission of corneal damage was seen for 86% of our cohort, and improved National Institutes of Health scores for 73%, of whom 8% achieved the best score of 0 (ie, non-dry eye). Similar results were seen at later time points. Comparing outcomes for our patient cohort to those determined retrospectively for patients in our institutional database revealed a 5-year overall survival (OS) of 65%. This OS is comparable to patients with limited cGVHD (75%) and is superior to that of patients with nonocular extensive cGVHD or without cGVHD (30% and 59%, respectively) (P = .013). Our results suggest that platelet-derived eye drops are a safe, practical, and well-tolerated therapeutic option that offers substantial benefits for most patients affected by ocular cGVHD at onset. The favorable OS of our patient cohort

  7. Differences in levels of platelet-derived microparticles in platelet components prepared using the platelet rich plasma, buffy coat, and apheresis procedures.

    Science.gov (United States)

    Noulsri, Egarit; Udomwinijsilp, Prapaporn; Lerdwana, Surada; Chongkolwatana, Viroje; Permpikul, Parichart

    2017-04-01

    There has been an increased interest in platelet-derived microparticles (PMPs) in transfusion medicine. Little is known about PMP status during the preparation of platelet concentrates for transfusion. The aim of this study is to compare the PMP levels in platelet components prepared using the buffy coat (BC), platelet-rich plasma platelet concentrate (PRP-PC), and apheresis (AP) processes. Platelet components were prepared using the PRP-PC and BC processes. Apheresis platelets were prepared using the Trima Accel and Amicus instruments. The samples were incubated with annexin A5-FITC, CD41-PE, and CD62P-APC. At day 1 after processing, the PMPs and activated platelets were determined using flow cytometry. Both the percentage and number of PMPs were higher in platelet components prepared using the Amicus instrument (2.6±1.8, 32802±19036 particles/μL) than in platelet components prepared using the Trima Accel instrument (0.5±0.4, 7568±5298 particles/μL), BC (1.2±0.6, 12,920±6426 particles/μL), and PRP-PC (0.9±0.6, 10731±5514 particles/μL). Both the percentage and number of activated platelets were higher in platelet components prepared using the Amicus instrument (33.2±13.9, 427553±196965 cells/μL) than in platelet components prepared using the Trima Accel instrument (16.2±6.1, 211209±87706 cells/μL), BC (12.9±3.2, 140624±41003 cells/μL), and PRP-PC (21.1±6.3, 265210±86257 cells/μL). The study suggests high variability of PMPs and activated platelets in platelet components prepared using different processes. This result may be important in validating the instruments involved in platelet blood collection and processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Time-dependent inhibitory effects of cGMP-analogues on thrombin-induced platelet-derived microparticles formation, platelet aggregation, and P-selectin expression

    International Nuclear Information System (INIS)

    Nygaard, Gyrid; Herfindal, Lars; Kopperud, Reidun; Aragay, Anna M.; Holmsen, Holm; Døskeland, Stein Ove; Kleppe, Rune; Selheim, Frode

    2014-01-01

    Highlights: • We investigated the impact of cyclic nucleotide analogues on platelet activation. • Different time dependence were found for inhibition of platelet activation. • Additive effect was found using PKA- and PKG-activating analogues. • Our results may explain some of the discrepancies reported for cNMP signalling. - Abstract: In platelets, nitric oxide (NO) activates cGMP/PKG signalling, whereas prostaglandins and adenosine signal through cAMP/PKA. Cyclic nucleotide signalling has been considered to play an inhibitory role in platelets. However, an early stimulatory effect of NO and cGMP-PKG signalling in low dose agonist-induced platelet activation have recently been suggested. Here, we investigated whether different experimental conditions could explain some of the discrepancy reported for platelet cGMP-PKG-signalling. We treated gel-filtered human platelets with cGMP and cAMP analogues, and used flow cytometric assays to detect low dose thrombin-induced formation of small platelet aggregates, single platelet disappearance (SPD), platelet-derived microparticles (PMP) and thrombin receptor agonist peptide (TRAP)-induced P-selectin expression. All four agonist-induced platelet activation phases were blocked when platelets were costimulated with the PKG activators 8-Br-PET-cGMP or 8-pCPT-cGMP and low-doses of thrombin or TRAP. However, extended incubation with 8-Br-PET-cGMP decreased its inhibition of TRAP-induced P-selectin expression in a time-dependent manner. This effect did not involve desensitisation of PKG or PKA activity, measured as site-specific VASP phosphorylation. Moreover, PKG activators in combination with the PKA activator Sp-5,6-DCL-cBIMPS revealed additive inhibitory effect on TRAP-induced P-selectin expression. Taken together, we found no evidence for a stimulatory role of cGMP/PKG in platelets activation and conclude rather that cGMP/PKG signalling has an important inhibitory function in human platelet activation

  9. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  10. RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research.

    Science.gov (United States)

    Heasly, Benjamin S; Cottaris, Nicolas P; Lichtman, Daniel P; Xiao, Bei; Brainard, David H

    2014-02-07

    RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3.

  11. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  12. Moisture movements in render on brick wall

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann

    2003-01-01

    A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...

  13. Physically based rendering from theory to implementation

    CERN Document Server

    Pharr, Matt

    2010-01-01

    "Physically Based Rendering, 2nd Edition" describes both the mathematical theory behind a modern photorealistic rendering system as well as its practical implementation. A method - known as 'literate programming'- combines human-readable documentation and source code into a single reference that is specifically designed to aid comprehension. The result is a stunning achievement in graphics education. Through the ideas and software in this book, you will learn to design and employ a full-featured rendering system for creating stunning imagery. This book features new sections on subsurface scattering, Metropolis light transport, precomputed light transport, multispectral rendering, and much more. It includes a companion site complete with source code for the rendering system described in the book, with support for Windows, OS X, and Linux. Code and text are tightly woven together through a unique indexing feature that lists each function, variable, and method on the page that they are first described.

  14. RenderGAN: Generating Realistic Labeled Data

    Directory of Open Access Journals (Sweden)

    Leon Sixt

    2018-06-01

    Full Text Available Deep Convolutional Neuronal Networks (DCNNs are showing remarkable performance on many computer vision tasks. Due to their large parameter space, they require many labeled samples when trained in a supervised setting. The costs of annotating data manually can render the use of DCNNs infeasible. We present a novel framework called RenderGAN that can generate large amounts of realistic, labeled images by combining a 3D model and the Generative Adversarial Network framework. In our approach, image augmentations (e.g., lighting, background, and detail are learned from unlabeled data such that the generated images are strikingly realistic while preserving the labels known from the 3D model. We apply the RenderGAN framework to generate images of barcode-like markers that are attached to honeybees. Training a DCNN on data generated by the RenderGAN yields considerably better performance than training it on various baselines.

  15. Distributed rendering for multiview parallax displays

    Science.gov (United States)

    Annen, T.; Matusik, W.; Pfister, H.; Seidel, H.-P.; Zwicker, M.

    2006-02-01

    3D display technology holds great promise for the future of television, virtual reality, entertainment, and visualization. Multiview parallax displays deliver stereoscopic views without glasses to arbitrary positions within the viewing zone. These systems must include a high-performance and scalable 3D rendering subsystem in order to generate multiple views at real-time frame rates. This paper describes a distributed rendering system for large-scale multiview parallax displays built with a network of PCs, commodity graphics accelerators, multiple projectors, and multiview screens. The main challenge is to render various perspective views of the scene and assign rendering tasks effectively. In this paper we investigate two different approaches: Optical multiplexing for lenticular screens and software multiplexing for parallax-barrier displays. We describe the construction of large-scale multi-projector 3D display systems using lenticular and parallax-barrier technology. We have developed different distributed rendering algorithms using the Chromium stream-processing framework and evaluate the trade-offs and performance bottlenecks. Our results show that Chromium is well suited for interactive rendering on multiview parallax displays.

  16. Using growth factors in human extraction sockets: a histologic and histomorphometric evaluation of short-term healing

    NARCIS (Netherlands)

    Geurs, N.; Ntounis, A.; Vassilopoulos, P.; van der Velden, U.; Loos, B.G.; Reddy, M.

    2014-01-01

    Purpose: Ridge preservation protocols reduce crestal remodeling after tooth extraction. There is insufficient evidence on bone grafting in combination with platelet-rich plasma (PRP) or recombinant human platelet-derived growth factor (rhPDGF-BB). The aim of this study is to evaluate healing of

  17. Standardized rendering from IR surveillance motion imagery

    Science.gov (United States)

    Prokoski, F. J.

    2014-06-01

    Government agencies, including defense and law enforcement, increasingly make use of video from surveillance systems and camera phones owned by non-government entities.Making advanced and standardized motion imaging technology available to private and commercial users at cost-effective prices would benefit all parties. In particular, incorporating thermal infrared into commercial surveillance systems offers substantial benefits beyond night vision capability. Face rendering is a process to facilitate exploitation of thermal infrared surveillance imagery from the general area of a crime scene, to assist investigations with and without cooperating eyewitnesses. Face rendering automatically generates greyscale representations similar to police artist sketches for faces in surveillance imagery collected from proximate locations and times to a crime under investigation. Near-realtime generation of face renderings can provide law enforcement with an investigation tool to assess witness memory and credibility, and integrate reports from multiple eyewitnesses, Renderings can be quickly disseminated through social media to warn of a person who may pose an immediate threat, and to solicit the public's help in identifying possible suspects and witnesses. Renderings are pose-standardized so as to not divulge the presence and location of eyewitnesses and surveillance cameras. Incorporation of thermal infrared imaging into commercial surveillance systems will significantly improve system performance, and reduce manual review times, at an incremental cost that will continue to decrease. Benefits to criminal justice would include improved reliability of eyewitness testimony and improved accuracy of distinguishing among minority groups in eyewitness and surveillance identifications.

  18. Earth mortars and earth-lime renders

    Directory of Open Access Journals (Sweden)

    Maria Fernandes

    2008-01-01

    Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

  19. Digital color acquisition, perception, coding and rendering

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    In this book the authors identify the basic concepts and recent advances in the acquisition, perception, coding and rendering of color. The fundamental aspects related to the science of colorimetry in relation to physiology (the human visual system) are addressed, as are constancy and color appearance. It also addresses the more technical aspects related to sensors and the color management screen. Particular attention is paid to the notion of color rendering in computer graphics. Beyond color, the authors also look at coding, compression, protection and quality of color images and videos.

  20. Haptic rendering for simulation of fine manipulation

    CERN Document Server

    Wang, Dangxiao; Zhang, Yuru

    2014-01-01

    This book introduces the latest progress in six degrees of freedom (6-DoF) haptic rendering with the focus on a new approach for simulating force/torque feedback in performing tasks that require dexterous manipulation skills. One of the major challenges in 6-DoF haptic rendering is to resolve the conflict between high speed and high fidelity requirements, especially in simulating a tool interacting with both rigid and deformable objects in a narrow space and with fine features. The book presents a configuration-based optimization approach to tackle this challenge. Addressing a key issue in man

  1. Blender cycles lighting and rendering cookbook

    CERN Document Server

    Iraci, Bernardo

    2013-01-01

    An in-depth guide full of step-by-step recipes to explore the concepts behind the usage of Cycles. Packed with illustrations, and lots of tips and tricks; the easy-to-understand nature of the book will help the reader understand even the most complex concepts with ease.If you are a digital artist who already knows your way around Blender, and you want to learn about the new Cycles' rendering engine, this is the book for you. Even experts will be able to pick up new tips and tricks to make the most of the rendering capabilities of Cycles.

  2. GPU Pro 5 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2014-01-01

    In GPU Pro5: Advanced Rendering Techniques, section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Marius Bjorge have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book covers rendering, lighting, effects in image space, mobile devices, 3D engine design, and compute. It explores rasterization of liquids, ray tracing of art assets that would otherwise be used in a rasterized engine, physically based area lights, volumetric light

  3. Fast rendering of scanned room geometries

    DEFF Research Database (Denmark)

    Olesen, Søren Krarup; Markovic, Milos; Hammershøi, Dorte

    2014-01-01

    Room acoustics are rendered in Virtual Realities based on models of the real world. These are typically rather coarse representations of the true geometry resulting in room impulse responses with a lack of natural detail. This problem can be overcome by using data scanned by sensors, such as e...

  4. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  5. Free-viewpoint depth image based rendering

    NARCIS (Netherlands)

    Zinger, S.; Do, Q.L.; With, de P.H.N.

    2010-01-01

    In 3D TV research, one approach is to employ multiple cameras for creating a 3D multi-view signal with the aim to make interactive free-viewpoint selection possible in 3D TV media. This paper explores a new rendering algorithm that enables to compute a free-viewpoint between two reference views from

  6. RAY TRACING RENDER MENGGUNAKAN FRAGMENT ANTI ALIASING

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2008-07-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Rendering is generating surface and three-dimensional effects on an object displayed on a monitor screen. Ray tracing as a rendering method that traces ray for each image pixel has a drawback, that is, aliasing (jaggies effect. There are some methods for executing anti aliasing. One of those methods is OGSS (Ordered Grid Super Sampling. OGSS is able to perform aliasing well. However, this method requires more computation time since sampling of all pixels in the image will be increased. Fragment Anti Aliasing (FAA is a new alternative method that can cope with the drawback. FAA will check the image when performing rendering to a scene. Jaggies effect is only happened at curve and gradient object. Therefore, only this part of object that will experience sampling magnification. After this sampling magnification and the pixel values are computed, then downsample is performed to retrieve the original pixel values. Experimental results show that the software can implement ray tracing well in order to form images, and it can implement FAA and OGSS technique to perform anti aliasing. In general, rendering using FAA is faster than using OGSS

  7. Increased levels of specific leukocyte- and platelet-derived substances during normal anti-tetanus antibody synthesis in patients with inactive Crohn disease

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Mortensen, T; Holten-Andersen, M

    2001-01-01

    , vascular endothelial growth factor (VEGF), tissue inhibitor of metalloproteinases-1 (TIMP-1), plasminogen activator inhibitor type-1 (PAI-1) and myeloperoxidase (MPO) were determined in serum or plasma obtained on the same days. RESULTS: After inoculation anti-tetanus antibody levels were equally raised...... immunization in patients with Crohn disease and the subsequent release of various inflammatory mediators and growth factors in blood. METHODS: Ten patients with inactive disease and no concurrent medication and 12 age-and gender-matched healthy volunteers with anti-tetanus antibody levels less than 0.1 IU...... range and IL-6, TNF-alpha, MPO and histamine levels were unchanged in patients and volunteers during the study period. The levels of VEGF, TIMP-1 and PAI-1 were unchanged in the healthy volunteers during the study period, but were significantly (P

  8. Rendering Falling Leaves on Graphics Hardware

    OpenAIRE

    Marcos Balsa; Pere-Pau Vázquez

    2008-01-01

    There is a growing interest in simulating natural phenomena in computer graphics applications. Animating natural scenes in real time is one of the most challenging problems due to the inherent complexity of their structure, formed by millions of geometric entities, and the interactions that happen within. An example of natural scenario that is needed for games or simulation programs are forests. Forests are difficult to render because the huge amount of geometric entities and the large amount...

  9. Emission of VOC's from modified rendering process

    International Nuclear Information System (INIS)

    Bhatti, Z.A.; Raja, I.A.; Saddique, M.; Langenhove, H.V.

    2005-01-01

    Rendering technique for processing of dead animal and slaughterhouse wastes into valuable products. It involves cooking of raw material and later Sterilization was added to reduce the Bovine Spongiform Encephalopathy (BSE). Studies have been carried out on rendering emission, with the normal cooking process. Our study shows, that the sterilization step in rendering process increases the emission of volatile organic compounds (VOC's). Gas samples, containing VOC's, were analyzed by the GC/MS (Gas Chromatograph and Mass Spectrometry). The most important groups of compounds- alcohols and cyclic hydrocarbons were identified. In the group of alcohol; 1-butanol, l-pentanol and l-hexanol compounds were found while in the group of cyclic hydrocarbon; methyl cyclopentane and cyclohexane compounds were detected. Other groups like aldehyde, sulphur containing compounds, ketone and furan were also found. Some compounds, like l-pentanol, 2-methyl propanal, dimethyl disulfide and dimethyl trisulfide, which belong to these groups, cause malodor. It is important to know these compounds to treat odorous gasses. (author)

  10. Increased levels of specific leukocyte- and platelet-derived substances during normal anti-tetanus antibody synthesis in patients with inactive Crohn disease

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Mortensen, T; Holten-Andersen, M

    2001-01-01

    /ml were inoculated with 1 ml (6 Lf units) of tetanus toxoid vaccine. The anti-tetanus antibody levels were determined in serum obtained before inoculation and after 7, 14 and 28 days, respectively. C-reactive protein (CRP), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), histamine......, vascular endothelial growth factor (VEGF), tissue inhibitor of metalloproteinases-1 (TIMP-1), plasminogen activator inhibitor type-1 (PAI-1) and myeloperoxidase (MPO) were determined in serum or plasma obtained on the same days. RESULTS: After inoculation anti-tetanus antibody levels were equally raised...

  11. Haptic rendering foundations, algorithms, and applications

    CERN Document Server

    Lin, Ming C

    2008-01-01

    For a long time, human beings have dreamed of a virtual world where it is possible to interact with synthetic entities as if they were real. It has been shown that the ability to touch virtual objects increases the sense of presence in virtual environments. This book provides an authoritative overview of state-of-theart haptic rendering algorithms and their applications. The authors examine various approaches and techniques for designing touch-enabled interfaces for a number of applications, including medical training, model design, and maintainability analysis for virtual prototyping, scienti

  12. GPU Pro 4 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2013-01-01

    GPU Pro4: Advanced Rendering Techniques presents ready-to-use ideas and procedures that can help solve many of your day-to-day graphics programming challenges. Focusing on interactive media and games, the book covers up-to-date methods producing real-time graphics. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Sebastien St-Laurent have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book begins with discussions on the abi

  13. GPU PRO 3 Advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2012-01-01

    GPU Pro3, the third volume in the GPU Pro book series, offers practical tips and techniques for creating real-time graphics that are useful to beginners and seasoned game and graphics programmers alike. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Wessam Bahnassi, and Sebastien St-Laurent have once again brought together a high-quality collection of cutting-edge techniques for advanced GPU programming. With contributions by more than 50 experts, GPU Pro3: Advanced Rendering Techniques covers battle-tested tips and tricks for creating interesting geometry, realistic sha

  14. Conservation of old renderings - the consolidation of rendering with loss of cohesion

    Directory of Open Access Journals (Sweden)

    Martha Tavares

    2008-01-01

    Full Text Available The study of external renderings in the scope of conservation and restoration has acquired in the last years great methodological, scientific and technical advances. These renderings are important elements of the built structure, for besides possessing a protection function, they possess often a decorative function of great relevance for the image of the monument. The maintenance of these renderings implies the conservation of traditional constructive techniques and the use of compatible materials, as similar to the originals as possible. The main objective of this study is to define a methodology of conservative restoration using strategies of maintenance of renderings and traditional constructive techniques. The minimum intervention principle is maintained as well as the use of materials compatible with the original ones. This paper describes the technique and products used for the consolidation of the loss of cohesion. The testing campaign was developed under controlled conditions, in laboratory, and in situ in order to evaluate their efficacy for the consolidation of old renders. A set of tests is presented to evaluate the effectiveness of the process. The results are analysed and a reflection is added referring to the applicability of these techniques. Finally the paper presents a proposal for further research.

  15. Validation of a colour rendering index based on memory colours

    OpenAIRE

    Smet, Kevin; Jost-Boissard, Sophie; Ryckaert, Wouter; Deconinck, Geert; Hanselaer, Peter

    2010-01-01

    In this paper the performance of a colour rendering index based on memory colours is investigated in comparison with the current CIE Colour Rendering Index, the NIST Colour Quality Scale and visual appreciation results obtained at CNRS at Lyon University for a set of 3000K and 4000K LED light sources. The Pearson and Spearman correlation coefficients between each colour rendering metric and the two sets of visual results were calculated. It was found that the memory colour based colour render...

  16. Development of a virtual speaking simulator using Image Based Rendering.

    Science.gov (United States)

    Lee, J M; Kim, H; Oh, M J; Ku, J H; Jang, D P; Kim, I Y; Kim, S I

    2002-01-01

    The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology has enabled the use of virtual reality (VR) for the treatment of the fear of public speaking. There are two techniques for building virtual environments for the treatment of this fear: a model-based and a movie-based method. Both methods have the weakness that they are unrealistic and not controllable individually. To understand these disadvantages, this paper presents a virtual environment produced with Image Based Rendering (IBR) and a chroma-key simultaneously. IBR enables the creation of realistic virtual environments where the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma-keys puts virtual audience members under individual control in the environment. In addition, real time capture technique is used in constructing the virtual environments enabling spoken interaction between the subject and a therapist or another subject.

  17. Immersive volume rendering of blood vessels

    Science.gov (United States)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  18. Photon Differential Splatting for Rendering Caustics

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny

    2014-01-01

    We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...

  19. Extreme simplification and rendering of point sets using algebraic multigrid

    NARCIS (Netherlands)

    Reniers, D.; Telea, A.C.

    2009-01-01

    We present a novel approach for extreme simplification of point set models, in the context of real-time rendering. Point sets are often rendered using simple point primitives, such as oriented discs. However, this requires using many primitives to render even moderately simple shapes. Often, one

  20. Simple Coatings to Render Polystyrene Protein Resistant

    Directory of Open Access Journals (Sweden)

    Marcelle Hecker

    2018-02-01

    Full Text Available Non-specific protein adsorption is detrimental to the performance of many biomedical devices. Polystyrene is a commonly used material in devices and thin films. Simple reliable surface modification of polystyrene to render it protein resistant is desired in particular for device fabrication and orthogonal functionalisation schemes. This report details modifications carried out on a polystyrene surface to prevent protein adsorption. The trialed surfaces included Pluronic F127 and PLL-g-PEG, adsorbed on polystyrene, using a polydopamine-assisted approach. Quartz crystal microbalance with dissipation (QCM-D results showed only short-term anti-fouling success of the polystyrene surface modified with F127, and the subsequent failure of the polydopamine intermediary layer in improving its stability. In stark contrast, QCM-D analysis proved the success of the polydopamine assisted PLL-g-PEG coating in preventing bovine serum albumin adsorption. This modified surface is equally as protein-rejecting after 24 h in buffer, and thus a promising simple coating for long term protein rejection of polystyrene.

  1. Lighting design for globally illuminated volume rendering.

    Science.gov (United States)

    Zhang, Yubo; Ma, Kwan-Liu

    2013-12-01

    With the evolution of graphics hardware, high quality global illumination becomes available for real-time volume rendering. Compared to local illumination, global illumination can produce realistic shading effects which are closer to real world scenes, and has proven useful for enhancing volume data visualization to enable better depth and shape perception. However, setting up optimal lighting could be a nontrivial task for average users. There were lighting design works for volume visualization but they did not consider global light transportation. In this paper, we present a lighting design method for volume visualization employing global illumination. The resulting system takes into account view and transfer-function dependent content of the volume data to automatically generate an optimized three-point lighting environment. Our method fully exploits the back light which is not used by previous volume visualization systems. By also including global shadow and multiple scattering, our lighting system can effectively enhance the depth and shape perception of volumetric features of interest. In addition, we propose an automatic tone mapping operator which recovers visual details from overexposed areas while maintaining sufficient contrast in the dark areas. We show that our method is effective for visualizing volume datasets with complex structures. The structural information is more clearly and correctly presented under the automatically generated light sources.

  2. Brain ageing changes proteoglycan sulfation, rendering perineuronal nets more inhibitory.

    Science.gov (United States)

    Foscarin, Simona; Raha-Chowdhury, Ruma; Fawcett, James W; Kwok, Jessica C F

    2017-06-28

    Chondroitin sulfate (CS) proteoglycans in perineuronal nets (PNNs) from the central nervous system (CNS) are involved in the control of plasticity and memory. Removing PNNs reactivates plasticity and restores memory in models of Alzheimer's disease and ageing. Their actions depend on the glycosaminoglycan (GAG) chains of CS proteoglycans, which are mainly sulfated in the 4 (C4S) or 6 (C6S) positions. While C4S is inhibitory, C6S is more permissive to axon growth, regeneration and plasticity. C6S decreases during critical period closure. We asked whether there is a late change in CS-GAG sulfation associated with memory loss in aged rats. Immunohistochemistry revealed a progressive increase in C4S and decrease in C6S from 3 to 18 months. GAGs extracted from brain PNNs showed a large reduction in C6S at 12 and 18 months, increasing the C4S/C6S ratio. There was no significant change in mRNA levels of the chondroitin sulfotransferases. PNN GAGs were more inhibitory to axon growth than those from the diffuse extracellular matrix. The 18-month PNN GAGs were more inhibitory than 3-month PNN GAGs. We suggest that the change in PNN GAG sulfation in aged brains renders the PNNs more inhibitory, which lead to a decrease in plasticity and adversely affect memory.

  3. Hybrid rendering of the chest and virtual bronchoscopy [corrected].

    Science.gov (United States)

    Seemann, M D; Seemann, O; Luboldt, W; Gebicke, K; Prime, G; Claussen, C D

    2000-10-30

    Thin-section spiral computed tomography was used to acquire the volume data sets of the thorax. The tracheobronchial system and pathological changes of the chest were visualized using a color-coded surface rendering method. The structures of interest were then superimposed on a volume rendering of the other thoracic structures, thus producing a hybrid rendering. The hybrid rendering technique exploit the advantages of both rendering methods and enable virtual bronchoscopic examinations using different representation models. Virtual bronchoscopic examinations with a transparent color-coded shaded-surface model enables the simultaneous visualization of both the airways and the adjacent structures behind of the tracheobronchial wall and therefore, offers a practical alternative to fiberoptic bronchoscopy. Hybrid rendering and virtual endoscopy obviate the need for time consuming detailed analysis and presentation of axial source images.

  4. Innovative Lime Pozzolana Renders for Reconstruction of Historical Buildings

    International Nuclear Information System (INIS)

    Vejmelkova, E.; Maca, P.; Konvalinka, P.; Cerny, R.

    2011-01-01

    Bulk density, matrix density, open porosity, compressive strength, bending strength, water sorptivity, moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, specific heat capacity and thermal diffusivity of two innovative renovation renders on limepozzolana basis are analyzed. The obtained results are compared with reference lime plaster and two commercial renovation renders, and conclusions on the applicability of the particular renders in practical reconstruction works are drawn. (author)

  5. Fast algorithm for the rendering of three-dimensional surfaces

    Science.gov (United States)

    Pritt, Mark D.

    1994-02-01

    It is often desirable to draw a detailed and realistic representation of surface data on a computer graphics display. One such representation is a 3D shaded surface. Conventional techniques for rendering shaded surfaces are slow, however, and require substantial computational power. Furthermore, many techniques suffer from aliasing effects, which appear as jagged lines and edges. This paper describes an algorithm for the fast rendering of shaded surfaces without aliasing effects. It is much faster than conventional ray tracing and polygon-based rendering techniques and is suitable for interactive use. On an IBM RISC System/6000TM workstation it renders a 1000 X 1000 surface in about 7 seconds.

  6. Real-time photorealistic stereoscopic rendering of fire

    Science.gov (United States)

    Rose, Benjamin M.; McAllister, David F.

    2007-02-01

    We propose a method for real-time photorealistic stereo rendering of the natural phenomenon of fire. Applications include the use of virtual reality in fire fighting, military training, and entertainment. Rendering fire in real-time presents a challenge because of the transparency and non-static fluid-like behavior of fire. It is well known that, in general, methods that are effective for monoscopic rendering are not necessarily easily extended to stereo rendering because monoscopic methods often do not provide the depth information necessary to produce the parallax required for binocular disparity in stereoscopic rendering. We investigate the existing techniques used for monoscopic rendering of fire and discuss their suitability for extension to real-time stereo rendering. Methods include the use of precomputed textures, dynamic generation of textures, and rendering models resulting from the approximation of solutions of fluid dynamics equations through the use of ray-tracing algorithms. We have found that in order to attain real-time frame rates, our method based on billboarding is effective. Slicing is used to simulate depth. Texture mapping or 2D images are mapped onto polygons and alpha blending is used to treat transparency. We can use video recordings or prerendered high-quality images of fire as textures to attain photorealistic stereo.

  7. Method of producing hydrogen, and rendering a contaminated biomass inert

    Science.gov (United States)

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  8. Realistic Real-Time Outdoor Rendering in Augmented Reality

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  9. Extreme Simplification and Rendering of Point Sets using Algebraic Multigrid

    NARCIS (Netherlands)

    Reniers, Dennie; Telea, Alexandru

    2005-01-01

    We present a novel approach for extreme simplification of point set models in the context of real-time rendering. Point sets are often rendered using simple point primitives, such as oriented discs. However efficient, simple primitives are less effective in approximating large surface areas. A large

  10. Transform coding for hardware-accelerated volume rendering.

    Science.gov (United States)

    Fout, Nathaniel; Ma, Kwan-Liu

    2007-01-01

    Hardware-accelerated volume rendering using the GPU is now the standard approach for real-time volume rendering, although limited graphics memory can present a problem when rendering large volume data sets. Volumetric compression in which the decompression is coupled to rendering has been shown to be an effective solution to this problem; however, most existing techniques were developed in the context of software volume rendering, and all but the simplest approaches are prohibitive in a real-time hardware-accelerated volume rendering context. In this paper we present a novel block-based transform coding scheme designed specifically with real-time volume rendering in mind, such that the decompression is fast without sacrificing compression quality. This is made possible by consolidating the inverse transform with dequantization in such a way as to allow most of the reprojection to be precomputed. Furthermore, we take advantage of the freedom afforded by off-line compression in order to optimize the encoding as much as possible while hiding this complexity from the decoder. In this context we develop a new block classification scheme which allows us to preserve perceptually important features in the compression. The result of this work is an asymmetric transform coding scheme that allows very large volumes to be compressed and then decompressed in real-time while rendering on the GPU.

  11. Light Field Rendering for Head Mounted Displays using Pixel Reprojection

    DEFF Research Database (Denmark)

    Hansen, Anne Juhler; Klein, Jákup; Kraus, Martin

    2017-01-01

    Light field displays have advantages over traditional stereoscopic head mounted displays, for example, because they can overcome the vergence-accommodation conflict. However, rendering light fields can be a heavy task for computers due to the number of images that have to be rendered. Since much ...

  12. Realistic real-time outdoor rendering in augmented reality.

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  13. Media Presentation Synchronisation for Non-monolithic Rendering Architectures

    NARCIS (Netherlands)

    I. Vaishnavi (Ishan); D.C.A. Bulterman (Dick); P.S. Cesar Garcia (Pablo Santiago); B. Gao (Bo)

    2007-01-01

    htmlabstractNon-monolithic renderers are physically distributed media playback engines. Non-monolithic renderers may use a number of different underlying network connection types to transmit media items belonging to a presentation. There is therefore a need for a media based and inter-network- type

  14. Evaluating progressive-rendering algorithms in appearance design tasks.

    Science.gov (United States)

    Jiawei Ou; Karlik, Ondrej; Křivánek, Jaroslav; Pellacini, Fabio

    2013-01-01

    Progressive rendering is becoming a popular alternative to precomputational approaches to appearance design. However, progressive algorithms create images exhibiting visual artifacts at early stages. A user study investigated these artifacts' effects on user performance in appearance design tasks. Novice and expert subjects performed lighting and material editing tasks with four algorithms: random path tracing, quasirandom path tracing, progressive photon mapping, and virtual-point-light rendering. Both the novices and experts strongly preferred path tracing to progressive photon mapping and virtual-point-light rendering. None of the participants preferred random path tracing to quasirandom path tracing or vice versa; the same situation held between progressive photon mapping and virtual-point-light rendering. The user workflow didn’t differ significantly with the four algorithms. The Web Extras include a video showing how four progressive-rendering algorithms converged (at http://youtu.be/ck-Gevl1e9s), the source code used, and other supplementary materials.

  15. Local and Global Illumination in the Volume Rendering Integral

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Chen, M

    2005-10-21

    This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

  16. Simplification of Visual Rendering in Simulated Prosthetic Vision Facilitates Navigation.

    Science.gov (United States)

    Vergnieux, Victor; Macé, Marc J-M; Jouffrais, Christophe

    2017-09-01

    Visual neuroprostheses are still limited and simulated prosthetic vision (SPV) is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprosthetic characteristics to restore various functions such as reading, objects and face recognition, object grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision. The resolution of current arrays of electrodes is not sufficient to allow navigation tasks without additional processing of the visual input. In this study, we simulated a low resolution array (15 × 18 electrodes, similar to a forthcoming generation of arrays) and evaluated the navigation abilities restored when visual information was processed with various computer vision algorithms to enhance the visual rendering. Three main visual rendering strategies were compared to a control rendering in a wayfinding task within an unknown environment. The control rendering corresponded to a resizing of the original image onto the electrode array size, according to the average brightness of the pixels. In the first rendering strategy, vision distance was limited to 3, 6, or 9 m, respectively. In the second strategy, the rendering was not based on the brightness of the image pixels, but on the distance between the user and the elements in the field of view. In the last rendering strategy, only the edges of the environments were displayed, similar to a wireframe rendering. All the tested renderings, except the 3 m limitation of the viewing distance, improved navigation performance and decreased cognitive load. Interestingly, the distance-based and wireframe renderings also improved the cognitive mapping of the unknown environment. These results show that low resolution implants are usable for wayfinding if specific computer vision algorithms are used to select and display appropriate

  17. Biofuels. Altered sterol composition renders yeast thermotolerant

    DEFF Research Database (Denmark)

    Caspeta, Luis; Chen, Yun; Ghiaci, Payam

    2014-01-01

    adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ≥40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol......Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ≥40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used...... desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype....

  18. Light Field Rendering for Head Mounted Displays using Pixel Reprojection

    DEFF Research Database (Denmark)

    Hansen, Anne Juhler; Klein, Jákup; Kraus, Martin

    2017-01-01

    of the information of the different images is redundant, we use pixel reprojection from the corner cameras to compute the remaining images in the light field. We compare the reprojected images with directly rendered images in a user test. In most cases, the users were unable to distinguish the images. In extreme...... cases, the reprojection approach is not capable of creating the light field. We conclude that pixel reprojection is a feasible method for rendering light fields as far as quality of perspective and diffuse shading is concerned, but render time needs to be reduced to make the method practical....

  19. Growth

    Science.gov (United States)

    John R. Jones; George A. Schier

    1985-01-01

    This chapter considers aspen growth as a process, and discusses some characteristics of the growth and development of trees and stands. For the most part, factors affecting growth are discussed elsewhere, particularly in the GENETICS AND VARIATION chapter and in chapters in PART 11. ECOLOGY. Aspen growth as it relates to wood production is examined in the WOOD RESOURCE...

  20. View compensated compression of volume rendered images for remote visualization.

    Science.gov (United States)

    Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

    2009-07-01

    Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

  1. Factors affecting extension workers in their rendering of effective ...

    African Journals Online (AJOL)

    Factors affecting extension workers in their rendering of effective service to pre and ... Small, micro and medium entrepreneurs play an important role in economic ... such as production, marketing and management to adequately service the ...

  2. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera; Kruger, Jens; Moller, Torsten; Hadwiger, Markus

    2014-01-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined

  3. Experiencing "Macbeth": From Text Rendering to Multicultural Performance.

    Science.gov (United States)

    Reisin, Gail

    1993-01-01

    Shows how one teacher used innovative methods in teaching William Shakespeare's "Macbeth." Outlines student assignments including text renderings, rewriting a scene from the play, and creating a multicultural scrapbook for the play. (HB)

  4. Insurance of professional responsibility at medical aid rendering

    Directory of Open Access Journals (Sweden)

    Abyzova N.V.

    2011-12-01

    Full Text Available The article discusses the necessity of adoption of professional responsibility insurance act into the public health service. It is considered as the basic mechanism of compensation in case of damage to a patient at medical aid rendering

  5. Integral image rendering procedure for aberration correction and size measurement.

    Science.gov (United States)

    Sommer, Holger; Ihrig, Andreas; Ebenau, Melanie; Flühs, Dirk; Spaan, Bernhard; Eichmann, Marion

    2014-05-20

    The challenge in rendering integral images is to use as much information preserved by the light field as possible to reconstruct a captured scene in a three-dimensional way. We propose a rendering algorithm based on the projection of rays through a detailed simulation of the optical path, considering all the physical properties and locations of the optical elements. The rendered images contain information about the correct size of imaged objects without the need to calibrate the imaging device. Additionally, aberrations of the optical system may be corrected, depending on the setup of the integral imaging device. We show simulation data that illustrates the aberration correction ability and experimental data from our plenoptic camera, which illustrates the capability of our proposed algorithm to measure size and distance. We believe this rendering procedure will be useful in the future for three-dimensional ophthalmic imaging of the human retina.

  6. Minoxidil Promotes Hair Growth through Stimulation of Growth Factor Release from Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Nahyun Choi

    2018-02-01

    Full Text Available Minoxidil directly promotes hair growth via the stimulation of dermal papilla (DP and epithelial cells. Alternatively, there is little evidence for indirect promotion of hair growth via stimulation of adipose-derived stem cells (ASCs. We investigated whether minoxidil stimulates ASCs and if increased growth factor secretion by ASCs facilitates minoxidil-induced hair growth. Telogen-to-anagen induction was examined in mice. Cultured DP cells and vibrissae hair follicle organ cultures were used to further examine the underlying mechanisms. Subcutaneous injection of minoxidil-treated ASCs accelerated telogen-to-anagen transition in mice, and increased hair weight at day 14 post-injection. Minoxidil did not alter ASC proliferation, but increased migration and tube formation. Minoxidil also increased the secretion of growth factors from ASCs, including chemokine (C-X-C motif ligand 1 (CXCL1, platelet-derived endothelial cell growth factor (PD-ECGF, and platelet-derived growth factor-C (PDGF-C. Minoxidil increased extracellular signal–regulated kinases 1/2 (ERK1/2 phosphorylation, and concomitant upregulation of PD-ECGF and PDGF-C mRNA levels were attenuated by an ERK inhibitor. Subcutaneous injection of CXCL1, PD-ECGF, or PDGF-C enhanced anagen induction in mice, and both CXCL1 and PDGF-C increased hair length in ex vivo organ culture. Treatment with CXCL1, PD-ECGF, or PDGF-C also increased the proliferation index in DP cells. Finally, topical application of CXCL1, PD-ECGF, or PDGF-C with 2% minoxidil enhanced anagen induction when compared to minoxidil alone. Minoxidil stimulates ASC motility and increases paracrine growth factor signaling. Minoxidil-stimulated secretion of growth factors by ASCs may enhance hair growth by promoting DP proliferation. Therefore, minoxidil can be used as an ASC preconditioning agent for hair regeneration.

  7. Minoxidil Promotes Hair Growth through Stimulation of Growth Factor Release from Adipose-Derived Stem Cells

    Science.gov (United States)

    Choi, Nahyun; Shin, Soyoung; Song, Sun U.; Sung, Jong-Hyuk

    2018-01-01

    Minoxidil directly promotes hair growth via the stimulation of dermal papilla (DP) and epithelial cells. Alternatively, there is little evidence for indirect promotion of hair growth via stimulation of adipose-derived stem cells (ASCs). We investigated whether minoxidil stimulates ASCs and if increased growth factor secretion by ASCs facilitates minoxidil-induced hair growth. Telogen-to-anagen induction was examined in mice. Cultured DP cells and vibrissae hair follicle organ cultures were used to further examine the underlying mechanisms. Subcutaneous injection of minoxidil-treated ASCs accelerated telogen-to-anagen transition in mice, and increased hair weight at day 14 post-injection. Minoxidil did not alter ASC proliferation, but increased migration and tube formation. Minoxidil also increased the secretion of growth factors from ASCs, including chemokine (C-X-C motif) ligand 1 (CXCL1), platelet-derived endothelial cell growth factor (PD-ECGF), and platelet-derived growth factor-C (PDGF-C). Minoxidil increased extracellular signal–regulated kinases 1/2 (ERK1/2) phosphorylation, and concomitant upregulation of PD-ECGF and PDGF-C mRNA levels were attenuated by an ERK inhibitor. Subcutaneous injection of CXCL1, PD-ECGF, or PDGF-C enhanced anagen induction in mice, and both CXCL1 and PDGF-C increased hair length in ex vivo organ culture. Treatment with CXCL1, PD-ECGF, or PDGF-C also increased the proliferation index in DP cells. Finally, topical application of CXCL1, PD-ECGF, or PDGF-C with 2% minoxidil enhanced anagen induction when compared to minoxidil alone. Minoxidil stimulates ASC motility and increases paracrine growth factor signaling. Minoxidil-stimulated secretion of growth factors by ASCs may enhance hair growth by promoting DP proliferation. Therefore, minoxidil can be used as an ASC preconditioning agent for hair regeneration. PMID:29495622

  8. Growth factor effects on costal chondrocytes for tissue engineering fibrocartilage

    Science.gov (United States)

    Johns, D.E.; Athanasiou, K.A.

    2010-01-01

    Tissue engineered fibrocartilage could become a feasible option for replacing tissues like the knee meniscus or temporomandibular joint disc. This study employed five growth factors insulin-like growth factor-I, transforming growth factor-β1, epidermal growth factor, platelet-derived growth factor-BB, and basic fibroblast growth factor in a scaffoldless approach with costal chondrocytes, attempting to improve biochemical and mechanical properties of engineered constructs. Samples were quantitatively assessed for total collagen, glycosaminoglycans, collagen type I, collagen type II, cells, compressive properties, and tensile properties at two time points. Most treated constructs were worse than the no growth factor control, suggesting a detrimental effect, but the IGF treatment tended to improve the constructs. Additionally, the 6wk time point was consistently better than 3wks, with total collagen, glycosaminoglycans, and aggregate modulus doubling during this time. Further optimization of the time in culture and exogenous stimuli will be important in making a more functional replacement tissue. PMID:18597118

  9. Beaming teaching application: recording techniques for spatial xylophone sound rendering

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Olesen, Søren Krarup

    2012-01-01

    BEAMING is a telepresence research project aiming at providing a multimodal interaction between two or more participants located at distant locations. One of the BEAMING applications allows a distant teacher to give a xylophone playing lecture to the students. Therefore, rendering of the xylophon...... to spatial improvements mainly in terms of the Apparent Source Width (ASW). Rendered examples are subjectively evaluated in listening tests by comparing them with binaural recording....

  10. Anisotropic 3D texture synthesis with application to volume rendering

    DEFF Research Database (Denmark)

    Laursen, Lasse Farnung; Ersbøll, Bjarne Kjær; Bærentzen, Jakob Andreas

    2011-01-01

    images using a 12.1 megapixel camera. Next, we extend the volume rendering pipeline by creating a transfer function which yields not only color and opacity from the input intensity, but also texture coordinates for our synthesized 3D texture. Thus, we add texture to the volume rendered images....... This method is applied to a high quality visualization of a pig carcass, where samples of meat, bone, and fat have been used to produce the anisotropic 3D textures....

  11. Graphical User Interfaces for Volume Rendering Applications in Medical Imaging

    OpenAIRE

    Lindfors, Lisa; Lindmark, Hanna

    2002-01-01

    Volume rendering applications are used in medical imaging in order to facilitate the analysis of three-dimensional image data. This study focuses on how to improve the usability of graphical user interfaces of these systems, by gathering user requirements. This is achieved by evaluations of existing systems, together with interviews and observations at clinics in Sweden that use volume rendering to some extent. The usability of the applications of today is not sufficient, according to the use...

  12. A Sort-Last Rendering System over an Optical Backplane

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kirihata

    2005-06-01

    Full Text Available Sort-Last is a computer graphics technique for rendering extremely large data sets on clusters of computers. Sort-Last works by dividing the data set into even-sized chunks for parallel rendering and then composing the images to form the final result. Since sort-last rendering requires the movement of large amounts of image data among cluster nodes, the network interconnecting the nodes becomes a major bottleneck. In this paper, we describe a sort-last rendering system implemented on a cluster of computers whose nodes are connected by an all-optical switch. The rendering system introduces the notion of the Photonic Computing Engine, a computing system built dynamically by using the optical switch to create dedicated network connections among cluster nodes. The sort-last volume rendering algorithm was implemented on the Photonic Computing Engine, and its performance is evaluated. Prelimi- nary experiments show that performance is affected by the image composition time and average payload size. In an attempt to stabilize the performance of the system, we have designed a flow control mechanism that uses feedback messages to dynamically adjust the data flow rate within the computing engine.

  13. Fast DRR splat rendering using common consumer graphics hardware

    International Nuclear Information System (INIS)

    Spoerk, Jakob; Bergmann, Helmar; Wanschitz, Felix; Dong, Shuo; Birkfellner, Wolfgang

    2007-01-01

    Digitally rendered radiographs (DRR) are a vital part of various medical image processing applications such as 2D/3D registration for patient pose determination in image-guided radiotherapy procedures. This paper presents a technique to accelerate DRR creation by using conventional graphics hardware for the rendering process. DRR computation itself is done by an efficient volume rendering method named wobbled splatting. For programming the graphics hardware, NVIDIAs C for Graphics (Cg) is used. The description of an algorithm used for rendering DRRs on the graphics hardware is presented, together with a benchmark comparing this technique to a CPU-based wobbled splatting program. Results show a reduction of rendering time by about 70%-90% depending on the amount of data. For instance, rendering a volume of 2x10 6 voxels is feasible at an update rate of 38 Hz compared to 6 Hz on a common Intel-based PC using the graphics processing unit (GPU) of a conventional graphics adapter. In addition, wobbled splatting using graphics hardware for DRR computation provides higher resolution DRRs with comparable image quality due to special processing characteristics of the GPU. We conclude that DRR generation on common graphics hardware using the freely available Cg environment is a major step toward 2D/3D registration in clinical routine

  14. Remote volume rendering pipeline for mHealth applications

    Science.gov (United States)

    Gutenko, Ievgeniia; Petkov, Kaloian; Papadopoulos, Charilaos; Zhao, Xin; Park, Ji Hwan; Kaufman, Arie; Cha, Ronald

    2014-03-01

    We introduce a novel remote volume rendering pipeline for medical visualization targeted for mHealth (mobile health) applications. The necessity of such a pipeline stems from the large size of the medical imaging data produced by current CT and MRI scanners with respect to the complexity of the volumetric rendering algorithms. For example, the resolution of typical CT Angiography (CTA) data easily reaches 512^3 voxels and can exceed 6 gigabytes in size by spanning over the time domain while capturing a beating heart. This explosion in data size makes data transfers to mobile devices challenging, and even when the transfer problem is resolved the rendering performance of the device still remains a bottleneck. To deal with this issue, we propose a thin-client architecture, where the entirety of the data resides on a remote server where the image is rendered and then streamed to the client mobile device. We utilize the display and interaction capabilities of the mobile device, while performing interactive volume rendering on a server capable of handling large datasets. Specifically, upon user interaction the volume is rendered on the server and encoded into an H.264 video stream. H.264 is ubiquitously hardware accelerated, resulting in faster compression and lower power requirements. The choice of low-latency CPU- and GPU-based encoders is particularly important in enabling the interactive nature of our system. We demonstrate a prototype of our framework using various medical datasets on commodity tablet devices.

  15. RenderSelect: a Cloud Broker Framework for Cloud Renderfarm Services

    OpenAIRE

    Ruby, Annette J; Aisha, Banu W; Subash, Chandran P

    2016-01-01

    In the 3D studios the animation scene files undergo a process called as rendering, where the 3D wire frame models are converted into 3D photorealistic images. As the rendering process is both a computationally intensive and a time consuming task, the cloud services based rendering in cloud render farms is gaining popularity among the animators. Though cloud render farms offer many benefits, the animators hesitate to move from their traditional offline rendering to cloud services based render ...

  16. Architecture for high performance stereoscopic game rendering on Android

    Science.gov (United States)

    Flack, Julien; Sanderson, Hugh; Shetty, Sampath

    2014-03-01

    Stereoscopic gaming is a popular source of content for consumer 3D display systems. There has been a significant shift in the gaming industry towards casual games for mobile devices running on the Android™ Operating System and driven by ARM™ and other low power processors. Such systems are now being integrated directly into the next generation of 3D TVs potentially removing the requirement for an external games console. Although native stereo support has been integrated into some high profile titles on established platforms like Windows PC and PS3 there is a lack of GPU independent 3D support for the emerging Android platform. We describe a framework for enabling stereoscopic 3D gaming on Android for applications on mobile devices, set top boxes and TVs. A core component of the architecture is a 3D game driver, which is integrated into the Android OpenGL™ ES graphics stack to convert existing 2D graphics applications into stereoscopic 3D in real-time. The architecture includes a method of analyzing 2D games and using rule based Artificial Intelligence (AI) to position separate objects in 3D space. We describe an innovative stereo 3D rendering technique to separate the views in the depth domain and render directly into the display buffer. The advantages of the stereo renderer are demonstrated by characterizing the performance in comparison to more traditional render techniques, including depth based image rendering, both in terms of frame rates and impact on battery consumption.

  17. Volume rendering in treatment planning for moving targets

    Energy Technology Data Exchange (ETDEWEB)

    Gemmel, Alexander [GSI-Biophysics, Darmstadt (Germany); Massachusetts General Hospital, Boston (United States); Wolfgang, John A.; Chen, George T.Y. [Massachusetts General Hospital, Boston (United States)

    2009-07-01

    Advances in computer technologies have facilitated the development of tools for 3-dimensional visualization of CT-data sets with volume rendering. The company Fovia has introduced a high definition volume rendering engine (HDVR trademark by Fovia Inc., Palo Alto, USA) that is capable of representing large CT data sets with high user interactivity even on standard PCs. Fovia provides a software development kit (SDK) that offers control of all the features of the rendering engine. We extended the SDK by functionalities specific to the task of treatment planning for moving tumors. This included navigation of the patient's anatomy in beam's eye view, fast point-and-click measurement of lung tumor trajectories as well as estimation of range perturbations due to motion by calculation of (differential) water equivalent path lengths for protons and carbon ions on 4D-CT data sets. We present patient examples to demonstrate the advantages and disadvantages of volume rendered images as compared to standard 2-dimensional axial plane images. Furthermore, we show an example of a range perturbation analysis. We conclude that volume rendering is a powerful technique for the representation and analysis of large time resolved data sets in treatment planning.

  18. A kinesthetic washout filter for force-feedback rendering.

    Science.gov (United States)

    Danieau, Fabien; Lecuyer, Anatole; Guillotel, Philippe; Fleureau, Julien; Mollet, Nicolas; Christie, Marc

    2015-01-01

    Today haptic feedback can be designed and associated to audiovisual content (haptic-audiovisuals or HAV). Although there are multiple means to create individual haptic effects, the issue of how to properly adapt such effects on force-feedback devices has not been addressed and is mostly a manual endeavor. We propose a new approach for the haptic rendering of HAV, based on a washout filter for force-feedback devices. A body model and an inverse kinematics algorithm simulate the user's kinesthetic perception. Then, the haptic rendering is adapted in order to handle transitions between haptic effects and to optimize the amplitude of effects regarding the device capabilities. Results of a user study show that this new haptic rendering can successfully improve the HAV experience.

  19. Clustered deep shadow maps for integrated polyhedral and volume rendering

    KAUST Repository

    Bornik, Alexander

    2012-01-01

    This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric objects and polyhedral models. Our system is the first hardware accelerated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such unified computation was limited to software-only rendering . Previous hardware accelerated techniques can handle only geometric or only volumetric scenes - both resulting in the loss of important properties of the original concept. Our approach supports interactive rendering of polyhedrally bounded volumetric objects on the GPU based on ray casting. The ray casting can be conveniently used for both the shadow map computation and the rendering. We show how anti-aliased high-quality shadows are feasible in scenes composed of multiple overlapping translucent objects, and how sparse scenes can be handled efficiently using clustered deep shadow maps. © 2012 Springer-Verlag.

  20. Mucosal detail at CT virtual reality: surface versus volume rendering.

    Science.gov (United States)

    Hopper, K D; Iyriboz, A T; Wise, S W; Neuman, J D; Mauger, D T; Kasales, C J

    2000-02-01

    To evaluate computed tomographic virtual reality with volumetric versus surface rendering. Virtual reality images were reconstructed for 27 normal or pathologic colonic, gastric, or bronchial structures in four ways: the transition zone (a) reconstructed separately from the wall by using volume rendering; (b) with attenuation equal to air; (c) with attenuation equal to wall (soft tissue); (d) with attenuation halfway between air and wall. The four reconstructed images were randomized. Four experienced imagers blinded to the reconstruction graded them from best to worst with predetermined criteria. All readers rated images with the transition zone as a separate structure as overwhelmingly superior (P Virtual reality is best with volume rendering, with the transition zone (mucosa) between the wall and air reconstructed as a separate structure.

  1. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias; Pascal Grosset, A.V.; Martin, Tobias; Pegoraro, Vincent; Smith, Sean T.; Hansen, Charles D.

    2011-01-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  2. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias

    2011-06-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  3. Chromium Renderserver: Scalable and Open Source Remote RenderingInfrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Brian; Ahern, Sean; Bethel, E. Wes; Brugger, Eric; Cook,Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2007-12-01

    Chromium Renderserver (CRRS) is software infrastructure thatprovides the ability for one or more users to run and view image outputfrom unmodified, interactive OpenGL and X11 applications on a remote,parallel computational platform equipped with graphics hardwareaccelerators via industry-standard Layer 7 network protocolsand clientviewers. The new contributions of this work include a solution to theproblem of synchronizing X11 and OpenGL command streams, remote deliveryof parallel hardware-accelerated rendering, and a performance analysis ofseveral different optimizations that are generally applicable to avariety of rendering architectures. CRRSis fully operational, Open Sourcesoftware.

  4. Growth factors and new periodontology

    Directory of Open Access Journals (Sweden)

    Paknejad M

    1999-06-01

    Full Text Available Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and"ndifferentiation by acting on specific receptors on the surface of cells and regulating events in wound"nhealing.They can be considered hormones that are not released in to the blood stream but have one a"nlocal action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion"ncycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted"nby fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor"n(PDGF, insulin like growth factor (IGF transforming growth factor (TGFa and (3 and bone"nmorphogenetic proteins BMPs that approximately are the most important of them. (BMPs could be"nused to control events during periodontal, craniofacial and implant wound healing through favoring bone"nformation"nAccording toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the"ncomponents of the periodontium."nThe aim of this study was to characterize growth factor and review the literature to determine the"nmechanism of their function, classification and application in implant and periodontal treatment.

  5. 7 CFR 54.1016 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT... rendered. Upon request of any applicant, all or any part of the contents of any report issued to the...

  6. Frequency Analysis of Gradient Estimators in Volume Rendering

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Lichtenbelt, Barthold B.A.; Malzbender, Tom

    1996-01-01

    Gradient information is used in volume rendering to classify and color samples along a ray. In this paper, we present an analysis of the theoretically ideal gradient estimator and compare it to some commonly used gradient estimators. A new method is presented to calculate the gradient at arbitrary

  7. Matching rendered and real world images by digital image processing

    Science.gov (United States)

    Mitjà, Carles; Bover, Toni; Bigas, Miquel; Escofet, Jaume

    2010-05-01

    Recent advances in computer-generated images (CGI) have been used in commercial and industrial photography providing a broad scope in product advertising. Mixing real world images with those rendered from virtual space software shows a more or less visible mismatching between corresponding image quality performance. Rendered images are produced by software which quality performance is only limited by the resolution output. Real world images are taken with cameras with some amount of image degradation factors as lens residual aberrations, diffraction, sensor low pass anti aliasing filters, color pattern demosaicing, etc. The effect of all those image quality degradation factors can be characterized by the system Point Spread Function (PSF). Because the image is the convolution of the object by the system PSF, its characterization shows the amount of image degradation added to any taken picture. This work explores the use of image processing to degrade the rendered images following the parameters indicated by the real system PSF, attempting to match both virtual and real world image qualities. The system MTF is determined by the slanted edge method both in laboratory conditions and in the real picture environment in order to compare the influence of the working conditions on the device performance; an approximation to the system PSF is derived from the two measurements. The rendered images are filtered through a Gaussian filter obtained from the taking system PSF. Results with and without filtering are shown and compared measuring the contrast achieved in different final image regions.

  8. The effects of multiview depth video compression on multiview rendering

    NARCIS (Netherlands)

    Merkle, P.; Morvan, Y.; Smolic, A.; Farin, D.S.; Mueller, K.; With, de P.H.N.; Wiegang, T.

    2009-01-01

    This article investigates the interaction between different techniques for depth compression and view synthesis rendering with multiview video plus scene depth data. Two different approaches for depth coding are compared, namely H.264/MVC, using temporal and inter-view reference images for efficient

  9. The effect of depth compression on multiview rendering quality

    NARCIS (Netherlands)

    Merkle, P.; Morvan, Y.; Smolic, A.; Farin, D.S.; Mueller, K..; With, de P.H.N.; Wiegand, T.

    2010-01-01

    This paper presents a comparative study on different techniques for depth-image compression and its implications on the quality of multiview video plus depth virtual view rendering. A novel coding algorithm for depth images that concentrates on their special characteristics, namely smooth regions

  10. The Peshitta Rendering of Psalm 25: Spelling, Synonyms, and Syntax’

    NARCIS (Netherlands)

    Dyk, J.W.; Loopstra, J.; Sokoloff, M.

    2013-01-01

    The very act of making a translation implies that the rendered text will differ from the source text. The underlying presupposition is that the grammar, syntax, and semantics of the source and target languages are sufficiently divergent as to warrant a translation. Translations differ in how close

  11. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  12. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel

    2014-11-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  13. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel; Dumusc, Raphael; Bilgili, Ahmet; Hernando, Juan; Eilemann, Stefan

    2014-01-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  14. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jü rgen P.; Acevedo-Feliz, Daniel; Mangan, John; Prudhomme, Andrew; Nguyen, Phi Khanh; Weber, Philip P.

    2012-01-01

    We present a new approach for how multiple users' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users' head positions and orientations. © 2012 IEEE.

  15. A Real-Time Sound Field Rendering Processor

    Directory of Open Access Journals (Sweden)

    Tan Yiyu

    2017-12-01

    Full Text Available Real-time sound field renderings are computationally intensive and memory-intensive. Traditional rendering systems based on computer simulations suffer from memory bandwidth and arithmetic units. The computation is time-consuming, and the sample rate of the output sound is low because of the long computation time at each time step. In this work, a processor with a hybrid architecture is proposed to speed up computation and improve the sample rate of the output sound, and an interface is developed for system scalability through simply cascading many chips to enlarge the simulated area. To render a three-minute Beethoven wave sound in a small shoe-box room with dimensions of 1.28 m × 1.28 m × 0.64 m, the field programming gate array (FPGA-based prototype machine with the proposed architecture carries out the sound rendering at run-time while the software simulation with the OpenMP parallelization takes about 12.70 min on a personal computer (PC with 32 GB random access memory (RAM and an Intel i7-6800K six-core processor running at 3.4 GHz. The throughput in the software simulation is about 194 M grids/s while it is 51.2 G grids/s in the prototype machine even if the clock frequency of the prototype machine is much lower than that of the PC. The rendering processor with a processing element (PE and interfaces consumes about 238,515 gates after fabricated by the 0.18 µm processing technology from the ROHM semiconductor Co., Ltd. (Kyoto Japan, and the power consumption is about 143.8 mW.

  16. 3D rendering and interactive visualization technology in large industry CT

    International Nuclear Information System (INIS)

    Xiao Yongshun; Zhang Li; Chen Zhiqiang; Kang Kejun

    2001-01-01

    This paper introduces the applications of interactive 3D rendering technology in the large ICT. It summarizes and comments on the iso-surfaces rendering and the direct volume rendering methods used in ICT. The paper emphasizes on the technical analysis of the 3D rendering process of ICT volume data sets, and summarizes the difficulties of the inspection subsystem design in large ICT

  17. 3D rendering and interactive visualization technology in large industry CT

    International Nuclear Information System (INIS)

    Xiao Yongshun; Zhang Li; Chen Zhiqiang; Kang Kejun

    2002-01-01

    The author introduces the applications of interactive 3D rendering technology in the large ICT. It summarizes and comments on the iso-surfaces rendering and the direct volume rendering methods used in ICT. The author emphasizes on the technical analysis of the 3D rendering process of ICT volume data sets, and summarizes the difficulties of the inspection subsystem design in large ICT

  18. Water driven leaching of biocides from paints and renders

    DEFF Research Database (Denmark)

    Bester, Kai; Vollertsen, Jes; Bollmann, Ulla E

    ) were so high, that rather professional urban gardening (flower and greenhouses) than handling of biocides from construction materials seem to be able to explain the findings. While the use in agriculture is restricted, the use in greenhouses is currently considered legal in Denmark. Leaching....../partitioning: Considering material properties, it was found out that, for all of the compounds the sorption (and leaching) is highly pH-dependent. It must be take into account that the pH in the porewater of the tested render materials is between 9 and 10 while the rainwater is around 5, thus making prediction difficult...... at this stage. For some of the compounds the sorption is dependent on the amount of polymer in the render, while it is only rarely of importance which polymer is used. Considering the interaction of weather with the leaching of biocides from real walls it turned out that a lot of parameters such as irradiation...

  19. Emotion rendering in auditory simulations of imagined walking styles

    DEFF Research Database (Denmark)

    Turchet, Luca; Rodá, Antonio

    2016-01-01

    This paper investigated how different emotional states of a walker can be rendered and recognized by means of footstep sounds synthesis algorithms. In a first experiment, participants were asked to render, according to imagined walking scenarios, five emotions (aggressive, happy, neutral, sad......, and tender) by manipulating the parameters of synthetic footstep sounds simulating various combinations of surface materials and shoes types. Results allowed to identify, for the involved emotions and sound conditions, the mean values and ranges of variation of two parameters, sound level and temporal...... distance between consecutive steps. Results were in accordance with those reported in previous studies on real walking, suggesting that expression of emotions in walking is independent from the real or imagined motor activity. In a second experiment participants were asked to identify the emotions...

  20. Visualization of plasma collision phenomenon by particle based rendering

    International Nuclear Information System (INIS)

    Yamamoto, Takeshi; Takagishi, Hironori; Hasegawa, Kyoko; Nakata, Susumu; Tanaka, Satoshi; Tanaka, Kazuo

    2012-01-01

    In this paper, we visualize plasma collision phenomenon based on XYT-space (space and time) volume data for supporting research in plasma physics. We create 3D volume data in the XYT-space by piling up a time series of XY-plane photo images taken in experiment. As a result, we can visualize as one still image all the time behavior of the plasma plume. Besides, we adopt 'fused' visualization based on particle based rendering technique. Using that technique, we can easily fuse volume rendering different materials, and compare physics of different elements in flexible ways. In addition, we propose the method to generate pseudo-3D images from pictures shoot by ICCD of two perspectives on the upper and side. (author)

  1. Tactile display for virtual 3D shape rendering

    CERN Document Server

    Mansutti, Alessandro; Bordegoni, Monica; Cugini, Umberto

    2017-01-01

    This book describes a novel system for the simultaneous visual and tactile rendering of product shapes which allows designers to simultaneously touch and see new product shapes during the conceptual phase of product development. This system offers important advantages, including potential cost and time savings, compared with the standard product design process in which digital 3D models and physical prototypes are often repeatedly modified until an optimal design is achieved. The system consists of a tactile display that is able to represent, within a real environment, the shape of a product. Designers can explore the rendered surface by touching curves lying on the product shape, selecting those curves that can be considered style features and evaluating their aesthetic quality. In order to physically represent these selected curves, a flexible surface is modeled by means of servo-actuated modules controlling a physical deforming strip. The tactile display is designed so as to be portable, low cost, modular,...

  2. Hybrid fur rendering: combining volumetric fur with explicit hair strands

    DEFF Research Database (Denmark)

    Andersen, Tobias Grønbeck; Falster, Viggo; Frisvad, Jeppe Revall

    2016-01-01

    Hair is typically modeled and rendered using either explicitly defined hair strand geometry or a volume texture of hair densities. Taken each on their own, these two hair representations have difficulties in the case of animal fur as it consists of very dense and thin undercoat hairs in combination...... with coarse guard hairs. Explicit hair strand geometry is not well-suited for the undercoat hairs, while volume textures are not well-suited for the guard hairs. To efficiently model and render both guard hairs and undercoat hairs, we present a hybrid technique that combines rasterization of explicitly...... defined guard hairs with ray marching of a prismatic shell volume with dynamic resolution. The latter is the key to practical combination of the two techniques, and it also enables a high degree of detail in the undercoat. We demonstrate that our hybrid technique creates a more detailed and soft fur...

  3. Growth Factor Mediated Signaling in Pancreatic Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Nandy, Debashis; Mukhopadhyay, Debabrata, E-mail: mukhopadhyay.debabrata@mayo.edu [Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, 200 First Street SW, Guggenheim 1321C, Rochester, MN 55905 (United States)

    2011-02-24

    Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed.

  4. Growth Factor Mediated Signaling in Pancreatic Pathogenesis

    International Nuclear Information System (INIS)

    Nandy, Debashis; Mukhopadhyay, Debabrata

    2011-01-01

    Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed

  5. Autostereoscopic image creation by hyperview matrix controlled single pixel rendering

    Science.gov (United States)

    Grasnick, Armin

    2017-06-01

    technology just with a simple equation. This formula can be utilized to create a specific hyperview matrix for a certain 3D display - independent of the technology used. A hyperview matrix may contain the references to loads of images and act as an instruction for a subsequent rendering process of particular pixels. Naturally, a single pixel will deliver an image with no resolution and does not provide any idea of the rendered scene. However, by implementing the method of pixel recycling, a 3D image can be perceived, even if all source images are different. It will be proven that several millions of perspectives can be rendered with the support of GPU rendering and benefit from the hyperview matrix. In result, a conventional autostereoscopic display, which is designed to represent only a few perspectives can be used to show a hyperview image by using a suitable hyperview matrix. It will be shown that a millions-of-views-hyperview-image can be presented on a conventional autostereoscopic display. For such an hyperview image it is required that all pixels of the displays are allocated by different source images. Controlled by the hyperview matrix, an adapted renderer can render a full hyperview image in real-time.

  6. Irregular Morphing for Real-Time Rendering of Large Terrain

    Directory of Open Access Journals (Sweden)

    S. Kalem

    2016-06-01

    Full Text Available The following paper proposes an alternative approach to the real-time adaptive triangulation problem. A new region-based multi-resolution approach for terrain rendering is described which improves on-the-fly the distribution of the density of triangles inside the tile after selecting appropriate Level-Of-Detail by an adaptive sampling. This proposed approach organizes the heightmap into a QuadTree of tiles that are processed independently. This technique combines the benefits of both Triangular Irregular Network approach and region-based multi-resolution approach by improving the distribution of the density of triangles inside the tile. Our technique morphs the initial regular grid of the tile to deformed grid in order to minimize approximation error. The proposed technique strives to combine large tile size and real-time processing while guaranteeing an upper bound on the screen space error. Thus, this approach adapts terrain rendering process to local surface characteristics and enables on-the-fly handling of large amount of terrain data. Morphing is based-on the multi-resolution wavelet analysis. The use of the D2WT multi-resolution analysis of the terrain height-map speeds up processing and permits to satisfy an interactive terrain rendering. Tests and experiments demonstrate that Haar B-Spline wavelet, well known for its properties of localization and its compact support, is suitable for fast and accurate redistribution. Such technique could be exploited in client-server architecture for supporting interactive high-quality remote visualization of very large terrain.

  7. Rendering potential wearable robot designs with the LOPES gait trainer.

    Science.gov (United States)

    Koopman, B; van Asseldonk, E H F; van der Kooij, H; van Dijk, W; Ronsse, R

    2011-01-01

    In recent years, wearable robots (WRs) for rehabilitation, personal assistance, or human augmentation are gaining increasing interest. To make these devices more energy efficient, radical changes to the mechanical structure of the device are being considered. However, it remains very difficult to predict how people will respond to, and interact with, WRs that differ in terms of mechanical design. Users may adjust their gait pattern in response to the mechanical restrictions or properties of the device. The goal of this pilot study is to show the feasibility of rendering the mechanical properties of different potential WR designs using the robotic gait training device LOPES. This paper describes a new method that selectively cancels the dynamics of LOPES itself and adds the dynamics of the rendered WR using two parallel inverse models. Adaptive frequency oscillators were used to get estimates of the joint position, velocity, and acceleration. Using the inverse models, different WR designs can be evaluated, eliminating the need to build several prototypes. As a proof of principle, we simulated the effect of a very simple WR that consisted of a mass attached to the ankles. Preliminary results show that we are partially able to cancel the dynamics of LOPES. Additionally, the simulation of the mass showed an increase in muscle activity but not in the same level as during the control, where subjects actually carried the mass. In conclusion, the results in this paper suggest that LOPES can be used to render different WRs. In addition, it is very likely that the results can be further optimized when more effort is put in retrieving proper estimations for the velocity and acceleration, which are required for the inverse models. © 2011 IEEE

  8. Software System for Vocal Rendering of Printed Documents

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2008-01-01

    Full Text Available The objective of this paper is to present a software system architecture developed to render the printed documents in a vocal form. On the other hand, in the paper are described the software solutions that exist as software components and are necessary for documents processing as well as for multimedia device controlling used by the system. The usefulness of this system is for people with visual disabilities that can access the contents of documents without that they be printed in Braille system or to exist in an audio form.

  9. 3D Volume Rendering and 3D Printing (Additive Manufacturing).

    Science.gov (United States)

    Katkar, Rujuta A; Taft, Robert M; Grant, Gerald T

    2018-07-01

    Three-dimensional (3D) volume-rendered images allow 3D insight into the anatomy, facilitating surgical treatment planning and teaching. 3D printing, additive manufacturing, and rapid prototyping techniques are being used with satisfactory accuracy, mostly for diagnosis and surgical planning, followed by direct manufacture of implantable devices. The major limitation is the time and money spent generating 3D objects. Printer type, material, and build thickness are known to influence the accuracy of printed models. In implant dentistry, the use of 3D-printed surgical guides is strongly recommended to facilitate planning and reduce risk of operative complications. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Partitioning of biocides between water and inorganic phases of render

    DEFF Research Database (Denmark)

    Urbanczyk, Michal; Bollmann, Ulla E.; Bester, Kai

    The use of biocides as additives for building materials has gained importance in recent years. These biocides are, e.g., applied to renders and paints to prevent them from microbial spoilage. However, these biocides can leach out into the environment. In order to better understand this leaching...... compared. The partitioning constants for calcium carbonate varied between 0.1 (isoproturon) and 1.1 (iodocarb) and 84.6 (dichlorooctylisothiazolinone), respectively. The results for barite, kaolinite and mica were in a similar range and usually the compounds with high partitioning constants for one mineral...

  11. Extracellular matrix organization modulates fibroblast growth and growth factor responsiveness.

    Science.gov (United States)

    Nakagawa, S; Pawelek, P; Grinnell, F

    1989-06-01

    To learn more about the relationship between extracellular matrix organization, cell shape, and cell growth control, we studied DNA synthesis by fibroblasts in collagen gels that were either attached to culture dishes or floating in culture medium during gel contraction. After 4 days of contraction, the collagen density (initially 1.5 mg/ml) reached 22 mg/ml in attached gels and 55 mg/ml in floating gels. After contraction, attached collagen gels were well organized; collagen fibrils were aligned in the plane of cell spreading; and fibroblasts had an elongated, bipolar morphology. Floating collagen gels, however, were unorganized; collagen fibrils were arranged randomly; and fibroblasts had a stellate morphology. DNA synthesis by fibroblasts in contracted collagen gels was suppressed if the gels were floating in medium but not if the gels were attached, and inhibition was independent of the extent of gel contraction. Therefore, growth of fibroblasts in contracted collagen gels could be regulated by differences in extracellular matrix organization and cell shape independently of extracellular matrix density. We also compared the responses of fibroblasts in contracted collagen gels and monolayer culture to peptide growth factors including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta, and interleukin 1. Cells in floating collagen gels were generally unresponsive to any of the growth factors. Cells in attached collagen gels and monolayer culture were affected similarly by fibroblast growth factor but not by the others. Our results indicate that extracellular matrix organization influenced not only cell growth, but also fibroblast responsiveness to peptide growth factors.

  12. Radionuclide cisternography: SPECT and 3D-rendering

    International Nuclear Information System (INIS)

    Henkes, H.; Huber, G.; Piepgras, U.; Hierholzer, J.; Cordes, M.

    1991-01-01

    Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of 111 In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns. (orig.) [de

  13. Non-Photorealistic Rendering in Chinese Painting of Animals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A set of algorithms is proposed in this paper to automatically transform 3D animal models to Chinese painting style. Inspired by real painting process in Chinese painting of animals, we divide the whole rendering process into two parts: borderline stroke making and interior shading. In borderline stroke making process we first find 3D model silhouettes in real-time depending on the viewing direction of a user. After retrieving silhouette information from all model edges, a stroke linking mechanism is applied to link these independent edges into a long stroke. Finally we grow a plain thin silhouette line to a stylus stroke with various widths at each control point and a 2D brush model is combined with it to simulate a Chinese painting stroke. In the interior shading pipeline, three stages are used to convert a Gouraud-shading image to a Chinese painting style image: color quantization, ink diffusion and box filtering. The color quantization stage assigns all pixels in an image into four color levels and each level represents a color layer in a Chinese painting. Ink diffusion stage is used to transfer inks and water between different levels and to grow areas in an irregular way. The box filtering stage blurs sharp borders between different levels to embellish the appearance of final interior shading image. In addition to automatic rendering, an interactive Chinese painting system which is equipped with friendly input devices can be also combined to generate more artistic Chinese painting images manually.

  14. Continuous Surface Rendering, Passing from CAD to Physical Representation

    Directory of Open Access Journals (Sweden)

    Mario Covarrubias

    2013-06-01

    Full Text Available This paper describes a desktop-mechatronic interface that has been conceived to support designers in the evaluation of aesthetic virtual shapes. This device allows a continuous and smooth free hand contact interaction on a real and developable plastic tape actuated by a servo-controlled mechanism. The objective in designing this device is to reproduce a virtual surface with a consistent physical rendering well adapted to designers' needs. The desktop-mechatronic interface consists in a servo-actuated plastic strip that has been devised and implemented using seven interpolation points. In fact, by using the MEC (Minimal Energy Curve Spline approach, a developable real surface is rendered taking into account the CAD geometry of the virtual shapes. In this paper, we describe the working principles of the interface by using both absolute and relative approaches to control the position on each single control point on the MEC spline. Then, we describe the methodology that has been implemented, passing from the CAD geometry, linked to VisualNastran in order to maintain the parametric properties of the virtual shape. Then, we present the co-simulation between VisualNastran and MATLAB/Simulink used for achieving this goal and controlling the system and finally, we present the results of the subsequent testing session specifically carried out to evaluate the accuracy and the effectiveness of the mechatronic device.

  15. Hardware-accelerated autostereogram rendering for interactive 3D visualization

    Science.gov (United States)

    Petz, Christoph; Goldluecke, Bastian; Magnor, Marcus

    2003-05-01

    Single Image Random Dot Stereograms (SIRDS) are an attractive way of depicting three-dimensional objects using conventional display technology. Once trained in decoupling the eyes' convergence and focusing, autostereograms of this kind are able to convey the three-dimensional impression of a scene. We present in this work an algorithm that generates SIRDS at interactive frame rates on a conventional PC. The presented system allows rotating a 3D geometry model and observing the object from arbitrary positions in real-time. Subjective tests show that the perception of a moving or rotating 3D scene presents no problem: The gaze remains focused onto the object. In contrast to conventional SIRDS algorithms, we render multiple pixels in a single step using a texture-based approach, exploiting the parallel-processing architecture of modern graphics hardware. A vertex program determines the parallax for each vertex of the geometry model, and the graphics hardware's texture unit is used to render the dot pattern. No data has to be transferred between main memory and the graphics card for generating the autostereograms, leaving CPU capacity available for other tasks. Frame rates of 25 fps are attained at a resolution of 1024x512 pixels on a standard PC using a consumer-grade nVidia GeForce4 graphics card, demonstrating the real-time capability of the system.

  16. Rendering of HDR content on LDR displays: an objective approach

    Science.gov (United States)

    Krasula, Lukáš; Narwaria, Manish; Fliegel, Karel; Le Callet, Patrick

    2015-09-01

    Dynamic range compression (or tone mapping) of HDR content is an essential step towards rendering it on traditional LDR displays in a meaningful way. This is however non-trivial and one of the reasons is that tone mapping operators (TMOs) usually need content-specific parameters to achieve the said goal. While subjective TMO parameter adjustment is the most accurate, it may not be easily deployable in many practical applications. Its subjective nature can also influence the comparison of different operators. Thus, there is a need for objective TMO parameter selection to automate the rendering process. To that end, we investigate into a new objective method for TMO parameters optimization. Our method is based on quantification of contrast reversal and naturalness. As an important advantage, it does not require any prior knowledge about the input HDR image and works independently on the used TMO. Experimental results using a variety of HDR images and several popular TMOs demonstrate the value of our method in comparison to default TMO parameter settings.

  17. The rendering context for stereoscopic 3D web

    Science.gov (United States)

    Chen, Qinshui; Wang, Wenmin; Wang, Ronggang

    2014-03-01

    3D technologies on the Web has been studied for many years, but they are basically monoscopic 3D. With the stereoscopic technology gradually maturing, we are researching to integrate the binocular 3D technology into the Web, creating a stereoscopic 3D browser that will provide users with a brand new experience of human-computer interaction. In this paper, we propose a novel approach to apply stereoscopy technologies to the CSS3 3D Transforms. Under our model, each element can create or participate in a stereoscopic 3D rendering context, in which 3D Transforms such as scaling, translation and rotation, can be applied and be perceived in a truly 3D space. We first discuss the underlying principles of stereoscopy. After that we discuss how these principles can be applied to the Web. A stereoscopic 3D browser with backward compatibility is also created for demonstration purposes. We take advantage of the open-source WebKit project, integrating the 3D display ability into the rendering engine of the web browser. For each 3D web page, our 3D browser will create two slightly different images, each representing the left-eye view and right-eye view, both to be combined on the 3D display to generate the illusion of depth. And as the result turns out, elements can be manipulated in a truly 3D space.

  18. Tomographic image reconstruction and rendering with texture-mapping hardware

    International Nuclear Information System (INIS)

    Azevedo, S.G.; Cabral, B.K.; Foran, J.

    1994-07-01

    The image reconstruction problem, also known as the inverse Radon transform, for x-ray computed tomography (CT) is found in numerous applications in medicine and industry. The most common algorithm used in these cases is filtered backprojection (FBP), which, while a simple procedure, is time-consuming for large images on any type of computational engine. Specially-designed, dedicated parallel processors are commonly used in medical CT scanners, whose results are then passed to graphics workstation for rendering and analysis. However, a fast direct FBP algorithm can be implemented on modern texture-mapping hardware in current high-end workstation platforms. This is done by casting the FBP algorithm as an image warping operation with summing. Texture-mapping hardware, such as that on the Silicon Graphics Reality Engine (TM), shows around 600 times speedup of backprojection over a CPU-based implementation (a 100 Mhz R4400 in this case). This technique has the further advantages of flexibility and rapid programming. In addition, the same hardware can be used for both image reconstruction and for volumetric rendering. The techniques can also be used to accelerate iterative reconstruction algorithms. The hardware architecture also allows more complex operations than straight-ray backprojection if they are required, including fan-beam, cone-beam, and curved ray paths, with little or no speed penalties

  19. Efficient visibility encoding for dynamic illumination in direct volume rendering.

    Science.gov (United States)

    Kronander, Joel; Jönsson, Daniel; Löw, Joakim; Ljung, Patric; Ynnerman, Anders; Unger, Jonas

    2012-03-01

    We present an algorithm that enables real-time dynamic shading in direct volume rendering using general lighting, including directional lights, point lights, and environment maps. Real-time performance is achieved by encoding local and global volumetric visibility using spherical harmonic (SH) basis functions stored in an efficient multiresolution grid over the extent of the volume. Our method enables high-frequency shadows in the spatial domain, but is limited to a low-frequency approximation of visibility and illumination in the angular domain. In a first pass, level of detail (LOD) selection in the grid is based on the current transfer function setting. This enables rapid online computation and SH projection of the local spherical distribution of visibility information. Using a piecewise integration of the SH coefficients over the local regions, the global visibility within the volume is then computed. By representing the light sources using their SH projections, the integral over lighting, visibility, and isotropic phase functions can be efficiently computed during rendering. The utility of our method is demonstrated in several examples showing the generality and interactive performance of the approach.

  20. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  1. Physically Based Rendering in the Nightshade NG Visualization Platform

    Science.gov (United States)

    Berglund, Karrie; Larey-Williams, Trystan; Spearman, Rob; Bogard, Arthur

    2015-01-01

    This poster describes our work on creating a physically based rendering model in Nightshade NG planetarium simulation and visualization software (project website: NightshadeSoftware.org). We discuss techniques used for rendering realistic scenes in the universe and dealing with astronomical distances in real time on consumer hardware. We also discuss some of the challenges of rewriting the software from scratch, a project which began in 2011.Nightshade NG can be a powerful tool for sharing data and visualizations. The desktop version of the software is free for anyone to download, use, and modify; it runs on Windows and Linux (and eventually Mac). If you are looking to disseminate your data or models, please stop by to discuss how we can work together.Nightshade software is used in literally hundreds of digital planetarium systems worldwide. Countless teachers and astronomy education groups run the software on flat screens. This wide use makes Nightshade an effective tool for dissemination to educators and the public.Nightshade NG is an especially powerful visualization tool when projected on a dome. We invite everyone to enter our inflatable dome in the exhibit hall to see this software in a 3D environment.

  2. Morphological pyramids in multiresolution MIP rendering of large volume data : Survey and new results

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    We survey and extend nonlinear signal decompositions based on morphological pyramids, and their application to multiresolution maximum intensity projection (MIP) volume rendering with progressive refinement and perfect reconstruction. The structure of the resulting multiresolution rendering

  3. Adaptive proxy map server for efficient vector spatial data rendering

    Science.gov (United States)

    Sayar, Ahmet

    2013-01-01

    The rapid transmission of vector map data over the Internet is becoming a bottleneck of spatial data delivery and visualization in web-based environment because of increasing data amount and limited network bandwidth. In order to improve both the transmission and rendering performances of vector spatial data over the Internet, we propose a proxy map server enabling parallel vector data fetching as well as caching to improve the performance of web-based map servers in a dynamic environment. Proxy map server is placed seamlessly anywhere between the client and the final services, intercepting users' requests. It employs an efficient parallelization technique based on spatial proximity and data density in case distributed replica exists for the same spatial data. The effectiveness of the proposed technique is proved at the end of the article by the application of creating map images enriched with earthquake seismic data records.

  4. Artist rendering of dust grains colliding at low speeds

    Science.gov (United States)

    2003-01-01

    Clues to the formation of planets and planetary rings -- like Saturn's dazzling ring system -- may be found by studying how dust grains interact as they collide at low speeds. To study the question of low-speed dust collisions, NASA sponsored the COLLisions Into Dust Experiment (COLLIDE) at the University of Colorado. It was designed to spring-launch marble-size projectiles into trays of powder similar to space or lunar dust. COLLIDE-1 (1998) discovered that collisions below a certain energy threshold eject no material. COLLIDE-2 was designed to identify where the threshold is. In COLLIDE-2, scientists nudged small projectiles into dust beds and recorded how the dust splashed outward (video frame at top; artist's rendering at bottom). The slowest impactor ejected no material and stuck in the target. The faster impactors produced ejecta; some rebounded while others stuck in the target.

  5. Latency in Distributed Acquisition and Rendering for Telepresence Systems.

    Science.gov (United States)

    Ohl, Stephan; Willert, Malte; Staadt, Oliver

    2015-12-01

    Telepresence systems use 3D techniques to create a more natural human-centered communication over long distances. This work concentrates on the analysis of latency in telepresence systems where acquisition and rendering are distributed. Keeping latency low is important to immerse users in the virtual environment. To better understand latency problems and to identify the source of such latency, we focus on the decomposition of system latency into sub-latencies. We contribute a model of latency and show how it can be used to estimate latencies in a complex telepresence dataflow network. To compare the estimates with real latencies in our prototype, we modify two common latency measurement methods. This presented methodology enables the developer to optimize the design, find implementation issues and gain deeper knowledge about specific sources of latency.

  6. Volumetric ambient occlusion for real-time rendering and games.

    Science.gov (United States)

    Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M

    2010-01-01

    This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.

  7. D.Vanwijnsberghe, Autour de la Madeleine Renders

    Directory of Open Access Journals (Sweden)

    Muriel Verbeeck-Boutin

    2008-10-01

    Full Text Available Institution fédérale belge de réputation internationale, l’Institut royal du Patrimoine artistique, à Bruxelles,  célèbre cette année son soixantième anniversaire: c’est l’occasion de rappeler le prestige dont jouit depuis des décennies cet institut de recherche, de formation et de diffusion du savoir. Pour souligner l’événement, l’IRPA publie le quatrième volume de la collection Scientia Artis. Il présente sous le titre Autour de la Madeleine Renders un ensemble de recherches qui documentent...

  8. On-the-Fly Decompression and Rendering of Multiresolution Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P; Cohen, J D

    2009-04-02

    We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

  9. Rendering Future Vegetation Change across Large Regions of the US

    Science.gov (United States)

    Sant'Anna Dias, Felipe; Gu, Yuting; Agarwalla, Yashika; Cheng, Yiwei; Patil, Sopan; Stieglitz, Marc; Turk, Greg

    2015-04-01

    We use two Machine Learning techniques, Decision Trees (DT) and Neural Networks (NN), to provide classified images and photorealistic renderings of future vegetation cover at three large regions in the US. The training data used to generate current vegetation cover include Landsat surface reflectance images, USGS Land Cover maps, 50 years of mean annual temperature and precipitation for the period 1950 - 2000, elevation, aspect and slope data. Present vegetation cover was generated on a 100m grid. Future vegetation cover for the period 2061- 2080 was predicted using the 1 km resolution bias corrected data from the NASA Goddard Institute for Space Studies Global Climate Model E simulation. The three test regions encompass a wide range of climatic gradients, topographic variation, and vegetation cover. The central Oregon site covers 19,182 square km and includes the Ochoco and Malheur National Forest. Vegetation cover is 50% evergreen forest and 50% shrubs and scrubland. The northwest Washington site covers 14,182 square km. Vegetation cover is 60% evergreen forest, 14% scrubs, 7% grassland, and 7% barren land. The remainder of the area includes deciduous forest, perennial snow cover, and wetlands. The third site, the Jemez mountain region of north central New Mexico, covers 5,500 square km. Vegetation cover is 47% evergreen forest, 31% shrubs, 13% grasses, and 3% deciduous forest. The remainder of the area includes developed and cultivated areas and wetlands. Using the above mentioned data sets we first trained our DT and NN models to reproduce current vegetation. The land cover classified images were compared directly to the USGS land cover data. The photorealistic generated vegetation images were compared directly to the remotely sensed surface reflectance maps. For all three sites, similarity between generated and observed vegetation cover was quite remarkable. The three trained models were then used to explore what the equilibrium vegetation would look like for

  10. Artist Material BRDF Database for Computer Graphics Rendering

    Science.gov (United States)

    Ashbaugh, Justin C.

    The primary goal of this thesis was to create a physical library of artist material samples. This collection provides necessary data for the development of a gonio-imaging system for use in museums to more accurately document their collections. A sample set was produced consisting of 25 panels and containing nearly 600 unique samples. Selected materials are representative of those commonly used by artists both past and present. These take into account the variability in visual appearance resulting from the materials and application techniques used. Five attributes of variability were identified including medium, color, substrate, application technique and overcoat. Combinations of these attributes were selected based on those commonly observed in museum collections and suggested by surveying experts in the field. For each sample material, image data is collected and used to measure an average bi-directional reflectance distribution function (BRDF). The results are available as a public-domain image and optical database of artist materials at art-si.org. Additionally, the database includes specifications for each sample along with other information useful for computer graphics rendering such as the rectified sample images and normal maps.

  11. TransCut: interactive rendering of translucent cutouts.

    Science.gov (United States)

    Li, Dongping; Sun, Xin; Ren, Zhong; Lin, Stephen; Tong, Yiying; Guo, Baining; Zhou, Kun

    2013-03-01

    We present TransCut, a technique for interactive rendering of translucent objects undergoing fracturing and cutting operations. As the object is fractured or cut open, the user can directly examine and intuitively understand the complex translucent interior, as well as edit material properties through painting on cross sections and recombining the broken pieces—all with immediate and realistic visual feedback. This new mode of interaction with translucent volumes is made possible with two technical contributions. The first is a novel solver for the diffusion equation (DE) over a tetrahedral mesh that produces high-quality results comparable to the state-of-art finite element method (FEM) of Arbree et al. but at substantially higher speeds. This accuracy and efficiency is obtained by computing the discrete divergences of the diffusion equation and constructing the DE matrix using analytic formulas derived for linear finite elements. The second contribution is a multiresolution algorithm to significantly accelerate our DE solver while adapting to the frequent changes in topological structure of dynamic objects. The entire multiresolution DE solver is highly parallel and easily implemented on the GPU. We believe TransCut provides a novel visual effect for heterogeneous translucent objects undergoing fracturing and cutting operations.

  12. Moisture Transfer through Facades Covered with Organic Binder Renders

    Directory of Open Access Journals (Sweden)

    Carmen DICO

    2013-07-01

    Full Text Available Year after year we witness the negative effect of water over buildings, caused by direct or indirect actions. This situation is obvious in case of old, historical building, subjected to this aggression for a long period of time, but new buildings are also affected. Moisture in building materials causes not only structural damage, but also reduces the thermal insulation capacity of building components.Materials like plasters or paints have been used historically for a long period of time, fulfilling two basics functions: Decoration and Protection. The most acute demands are made on exterior plasters, as they, besides being an important decorative element for the facade, must perform two different functions simultaneously: protect the substrate against weathering and moisture without sealing, providing it a certain ability to “breathe” (Heilen, 2005. In order to accomplish this aim, the first step is to understand the hygrothermal behavior of coating and substrate and define the fundamental principles of moisture transfer; According to Künzel’s Facade Protection Theory, two material properties play the most important role: Water absorption and Vapor permeability.In the context of recently adoption (2009 of the “harmonized” European standard EN 15824 – „Specifications for external renders and internal plasters based on organic binders”, this paper deals extensively with the interaction of the two mentioned above properties for the coating materials, covered by EN 15824.

  13. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair.

    Science.gov (United States)

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people's perception of a person's age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people's response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty.

  14. New light field camera based on physical based rendering tracing

    Science.gov (United States)

    Chung, Ming-Han; Chang, Shan-Ching; Lee, Chih-Kung

    2014-03-01

    Even though light field technology was first invented more than 50 years ago, it did not gain popularity due to the limitation imposed by the computation technology. With the rapid advancement of computer technology over the last decade, the limitation has been uplifted and the light field technology quickly returns to the spotlight of the research stage. In this paper, PBRT (Physical Based Rendering Tracing) was introduced to overcome the limitation of using traditional optical simulation approach to study the light field camera technology. More specifically, traditional optical simulation approach can only present light energy distribution but typically lack the capability to present the pictures in realistic scenes. By using PBRT, which was developed to create virtual scenes, 4D light field information was obtained to conduct initial data analysis and calculation. This PBRT approach was also used to explore the light field data calculation potential in creating realistic photos. Furthermore, we integrated the optical experimental measurement results with PBRT in order to place the real measurement results into the virtually created scenes. In other words, our approach provided us with a way to establish a link of virtual scene with the real measurement results. Several images developed based on the above-mentioned approaches were analyzed and discussed to verify the pros and cons of the newly developed PBRT based light field camera technology. It will be shown that this newly developed light field camera approach can circumvent the loss of spatial resolution associated with adopting a micro-lens array in front of the image sensors. Detailed operational constraint, performance metrics, computation resources needed, etc. associated with this newly developed light field camera technique were presented in detail.

  15. Digital tomosynthesis rendering of joint margins for arthritis assessment

    Science.gov (United States)

    Duryea, Jeffrey W.; Neumann, Gesa; Yoshioka, Hiroshi; Dobbins, James T., III

    2004-05-01

    PURPOSE: Rheumatoid arthritis (RA) of the hand is a significant healthcare problem. Techniques to accurately quantity the structural changes from RA are crucial for the development and prescription of therapies. Analysis of radiographic joint space width (JSW) is widely used and has demonstrated promise. However, radiography presents a 2D view of the joint. In this study we performed tomosynthesis reconstructions of proximal interphalangeal (PIP), and metacarpophalangeal (MCP) joints to measure the 3D joint structure. METHODS: We performed a reader study using simulated radiographs of 12 MCP and 12 PIP joints from skeletal specimens imaged with micro-CT. The tomosynthesis technique provided images of reconstructed planes with 0.75 mm spacing, which were presented to 2 readers with a computer tool. The readers were instructed to delineate the joint surfaces on tomosynthetic slices where they could visualize the margins. We performed a quantitative analysis of 5 slices surrounding the central portion of each joint. Reader-determined JSW was compared to a gold standard. As a figure of merit we calculated the average root-mean square deviation (RMSD). RESULTS: RMSD was 0.22 mm for both joints. For the individual joints, RMSD was 0.18 mm (MCP), and 0.26 mm (PIP). The reduced performance for the smaller PIP joints suggests that a slice spacing less than 0.75 mm may be more appropriate. CONCLUSIONS: We have demonstrated the capability of limited 3D rendering of joint surfaces using digital tomosynthesis. This technique promises to provide an improved method to visualize the structural changes of RA.

  16. Enhancement method for rendered images of home decoration based on SLIC superpixels

    Science.gov (United States)

    Dai, Yutong; Jiang, Xiaotong

    2018-04-01

    Rendering technology has been widely used in the home decoration industry in recent years for images of home decoration design. However, due to the fact that rendered images of home decoration design rely heavily on the parameters of renderer and the lights of scenes, most rendered images in this industry require further optimization afterwards. To reduce workload and enhance rendered images automatically, an algorithm utilizing neural networks is proposed in this manuscript. In addition, considering few extreme conditions such as strong sunlight and lights, SLIC superpixels based segmentation is used to choose out these bright areas of an image and enhance them independently. Finally, these chosen areas are merged with the entire image. Experimental results show that the proposed method effectively enhances the rendered images when compared with some existing algorithms. Besides, the proposed strategy is proven to be adaptable especially to those images with obvious bright parts.

  17. Novel Drosophila receptor that binds multiple growth factors

    International Nuclear Information System (INIS)

    Rosner, M.R.; Thompson, K.L.; Garcia, V.; Decker, S.J.

    1986-01-01

    The authors have recently reported the identification of a novel growth factor receptor from Drosophila cell cultures that has dual binding specificity for both insulin and epidermal growth factor (EGF). This 100 kDa protein is also antigenically related to the cytoplasmic region of the mammalian EGF receptor-tyrosine kinase. They now report that this protein binds to mammalian nerve growth factor and human transforming growth factor alpha as well as insulin and EGF with apparent dissociation constants ranging from 10 -6 to 10 -8 M. The 100 kDa protein can be affinity-labeled with these 125 I-labeled growth factors after immunoprecipitation with anti-EGF receptor antiserum. These four growth factors appear to share a common binding site, as evidenced by their ability to block affinity labelling by 125 I-insulin. No significant binding to the 100 kDa protein was observed with platelet-derived growth factor, transforming growth factor beta, or glucagon. The 100 kDa Drosophila protein has a unique ligand-binding spectrum with no direct counterpart in mammalian cells and may represent an evolutionary precursor of the mammalian receptors for these growth factors

  18. Influence of rendering methods on yield and quality of chicken fat recovered from broiler skin

    Directory of Open Access Journals (Sweden)

    Liang-Kun Lin

    2017-06-01

    Full Text Available Objective In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. Methods The yield and quality of the broiler skin fat rendered through high and lower energy microwave rendering (3.6 W/g for 10 min and 2.4 W/g for 10 min for high power microwave rendering (HPMR and high power microwave rendering (LPMR, respectively, oven baking (OB, at 180°C for 40 min, and water cooking (WC, boiling for 40 min were compared. Results Microwave-rendered skin exhibited the highest yields and fat recovery rates, followed by OB, and WC fats (p<0.05. HPMR fat had the highest L*, a*, and b* values, whereas WC fat had the highest moisture content, acid values, and thiobarbituric acid (TBA values (p<0.05. There was no significant difference in the acid value, peroxide value, and TBA values between HPMR and LPMR fats. Conclusion Microwave rendering at a power level of 3.6 W/g for 10 min is suggested base on the yield and quality of chicken fat.

  19. Real-time volume rendering of digital medical images on an iOS device

    Science.gov (United States)

    Noon, Christian; Holub, Joseph; Winer, Eliot

    2013-03-01

    Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

  20. Ultrastructure and growth factor content of equine platelet-rich fibrin gels.

    Science.gov (United States)

    Textor, Jamie A; Murphy, Kaitlin C; Leach, J Kent; Tablin, Fern

    2014-04-01

    To compare fiber diameter, pore area, compressive stiffness, gelation properties, and selected growth factor content of platelet-rich fibrin gels (PRFGs) and conventional fibrin gels (FGs). PRFGs and conventional FGs prepared from the blood of 10 healthy horses. Autologous fibrinogen was used to form conventional FGs. The PRFGs were formed from autologous platelet-rich plasma of various platelet concentrations (100 × 10³ platelets/μL, 250 × 10³ platelets/μL, 500 × 10³ platelets/μL, and 1,000 × 10³ platelets/μL). All gels contained an identical fibrinogen concentration (20 mg/mL). Fiber diameter and pore area were evaluated with scanning electron microscopy. Maximum gelation rate was assessed with spectrophotometry, and gel stiffness was determined by measuring the compressive modulus. Gel weights were measured serially over 14 days as an index of contraction (volume loss). Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were quantified with ELISAs. Fiber diameters were significantly larger and mean pore areas were significantly smaller in PRFGs than in conventional FGs. Gel weight decreased significantly over time, differed significantly between PRFGs and conventional FGs, and was significantly correlated with platelet concentration. Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were highest in gels and releasates derived from 1,000 × 10³ platelets/μL. The inclusion of platelets in FGs altered the architecture and increased the growth factor content of the resulting scaffold. Platelets may represent a useful means of modifying these gels for applications in veterinary and human regenerative medicine.

  1. Clinical Application of Growth Factors and Cytokines in Wound Healing

    Science.gov (United States)

    Barrientos, Stephan; Brem, Harold; Stojadinovic, Olivera; Tomic-Canic, Marjana

    2016-01-01

    Wound healing is a complex and dynamic biological process that involves the coordinated efforts of multiple cell types and is executed and regulated by numerous growth factors and cytokines. There has been a drive in the past two decades to study the therapeutic effects of various growth factors in the clinical management of non-healing wounds (e.g. pressure ulcers, chronic venous ulcers, diabetic foot ulcers). For this review, we conducted a nonline search of Medline and Pub Medical and critically analyzed the literature regarding the role of growth factors and cytokines in the management of these wounds. We focused on currently approved therapies, emerging therapies and future research possibilities. In this review we discuss four growth factors and cytokines currently being used on and off label for the healing of wounds. These include: granulocyte-macrophage colony stimulating factor (GM-CSF), platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF). While the clinical results of using growth factors and cytokines are encouraging, many studies involved a small sample size and are disparate in measured endpoints. Therefore, further research is required to provide definitive evidence of efficacy. PMID:24942811

  2. Three-dimensional spiral CT during arterial portography: comparison of three rendering techniques.

    Science.gov (United States)

    Heath, D G; Soyer, P A; Kuszyk, B S; Bliss, D F; Calhoun, P S; Bluemke, D A; Choti, M A; Fishman, E K

    1995-07-01

    The three most common techniques for three-dimensional reconstruction are surface rendering, maximum-intensity projection (MIP), and volume rendering. Surface-rendering algorithms model objects as collections of geometric primitives that are displayed with surface shading. The MIP algorithm renders an image by selecting the voxel with the maximum intensity signal along a line extended from the viewer's eye through the data volume. Volume-rendering algorithms sum the weighted contributions of all voxels along the line. Each technique has advantages and shortcomings that must be considered during selection of one for a specific clinical problem and during interpretation of the resulting images. With surface rendering, sharp-edged, clear three-dimensional reconstruction can be completed on modest computer systems; however, overlapping structures cannot be visualized and artifacts are a problem. MIP is computationally a fast technique, but it does not allow depiction of overlapping structures, and its images are three-dimensionally ambiguous unless depth cues are provided. Both surface rendering and MIP use less than 10% of the image data. In contrast, volume rendering uses nearly all of the data, allows demonstration of overlapping structures, and engenders few artifacts, but it requires substantially more computer power than the other techniques.

  3. 31 CFR 515.548 - Services rendered by Cuba to United States aircraft.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Services rendered by Cuba to United... REGULATIONS Licenses, Authorizations, and Statements of Licensing Policy § 515.548 Services rendered by Cuba to United States aircraft. Specific licenses are issued for payment to Cuba of charges for services...

  4. On the design of a real-time volume rendering engine

    NARCIS (Netherlands)

    Smit, Jaap; Wessels, H.L.F.; van der Horst, A.; Bentum, Marinus Jan

    1992-01-01

    An architecture for a Real-Time Volume Rendering Engine (RT-VRE) is given, capable of computing 750 × 750 × 512 samples from a 3D dataset at a rate of 25 images per second. The RT-VRE uses for this purpose 64 dedicated rendering chips, cooperating with 16 RISC-processors. A plane interpolator

  5. On the design of a real-time volume rendering engine

    NARCIS (Netherlands)

    Smit, Jaap; Wessels, H.J.; van der Horst, A.; Bentum, Marinus Jan

    1995-01-01

    An architecture for a Real-Time Volume Rendering Engine (RT-VRE) is given, capable of computing 750 × 750 × 512 samples from a 3D dataset at a rate of 25 images per second. The RT-VRE uses for this purpose 64 dedicated rendering chips, cooperating with 16 RISC-processors. A plane interpolator

  6. Method and system for rendering and interacting with an adaptable computing environment

    Science.gov (United States)

    Osbourn, Gordon Cecil [Albuquerque, NM; Bouchard, Ann Marie [Albuquerque, NM

    2012-06-12

    An adaptable computing environment is implemented with software entities termed "s-machines", which self-assemble into hierarchical data structures capable of rendering and interacting with the computing environment. A hierarchical data structure includes a first hierarchical s-machine bound to a second hierarchical s-machine. The first hierarchical s-machine is associated with a first layer of a rendering region on a display screen and the second hierarchical s-machine is associated with a second layer of the rendering region overlaying at least a portion of the first layer. A screen element s-machine is linked to the first hierarchical s-machine. The screen element s-machine manages data associated with a screen element rendered to the display screen within the rendering region at the first layer.

  7. An improved method of continuous LOD based on fractal theory in terrain rendering

    Science.gov (United States)

    Lin, Lan; Li, Lijun

    2007-11-01

    With the improvement of computer graphic hardware capability, the algorithm of 3D terrain rendering is going into the hot topic of real-time visualization. In order to solve conflict between the rendering speed and reality of rendering, this paper gives an improved method of terrain rendering which improves the traditional continuous level of detail technique based on fractal theory. This method proposes that the program needn't to operate the memory repeatedly to obtain different resolution terrain model, instead, obtains the fractal characteristic parameters of different region according to the movement of the viewpoint. Experimental results show that the method guarantees the authenticity of landscape, and increases the real-time 3D terrain rendering speed.

  8. Design and Implementation of High-Performance GIS Dynamic Objects Rendering Engine

    Science.gov (United States)

    Zhong, Y.; Wang, S.; Li, R.; Yun, W.; Song, G.

    2017-12-01

    Spatio-temporal dynamic visualization is more vivid than static visualization. It important to use dynamic visualization techniques to reveal the variation process and trend vividly and comprehensively for the geographical phenomenon. To deal with challenges caused by dynamic visualization of both 2D and 3D spatial dynamic targets, especially for different spatial data types require high-performance GIS dynamic objects rendering engine. The main approach for improving the rendering engine with vast dynamic targets relies on key technologies of high-performance GIS, including memory computing, parallel computing, GPU computing and high-performance algorisms. In this study, high-performance GIS dynamic objects rendering engine is designed and implemented for solving the problem based on hybrid accelerative techniques. The high-performance GIS rendering engine contains GPU computing, OpenGL technology, and high-performance algorism with the advantage of 64-bit memory computing. It processes 2D, 3D dynamic target data efficiently and runs smoothly with vast dynamic target data. The prototype system of high-performance GIS dynamic objects rendering engine is developed based SuperMap GIS iObjects. The experiments are designed for large-scale spatial data visualization, the results showed that the high-performance GIS dynamic objects rendering engine have the advantage of high performance. Rendering two-dimensional and three-dimensional dynamic objects achieve 20 times faster on GPU than on CPU.

  9. COMPANION ANIMALS SYMPOSIUM: Rendered ingredients significantly influence sustainability, quality, and safety of pet food.

    Science.gov (United States)

    Meeker, D L; Meisinger, J L

    2015-03-01

    The rendering industry collects and safely processes approximately 25 million t of animal byproducts each year in the United States. Rendering plants process a variety of raw materials from food animal production, principally offal from slaughterhouses, but include whole animals that die on farms or in transit and other materials such as bone, feathers, and blood. By recycling these byproducts into various protein, fat, and mineral products, including meat and bone meal, hydrolyzed feather meal, blood meal, and various types of animal fats and greases, the sustainability of food animal production is greatly enhanced. The rendering industry is conscious of its role in the prevention of disease and microbiological control and providing safe feed ingredients for livestock, poultry, aquaculture, and pets. The processing of otherwise low-value OM from the livestock production and meat processing industries through rendering drastically reduces the amount of waste. If not rendered, biological materials would be deposited in landfills, burned, buried, or inappropriately dumped with large amounts of carbon dioxide, ammonia, and other compounds polluting air and water. The majority of rendered protein products are used as animal feed. Rendered products are especially valuable to the livestock and pet food industries because of their high protein content, digestible AA levels (especially lysine), mineral availability (especially calcium and phosphorous), and relatively low cost in relation to their nutrient value. The use of these reclaimed and recycled materials in pet food is a much more sustainable model than using human food for pets.

  10. Three-dimensional rendering of segmented object using matlab - biomed 2010.

    Science.gov (United States)

    Anderson, Jeffrey R; Barrett, Steven F

    2010-01-01

    The three-dimensional rendering of microscopic objects is a difficult and challenging task that often requires specialized image processing techniques. Previous work has been described of a semi-automatic segmentation process of fluorescently stained neurons collected as a sequence of slice images with a confocal laser scanning microscope. Once properly segmented, each individual object can be rendered and studied as a three-dimensional virtual object. This paper describes the work associated with the design and development of Matlab files to create three-dimensional images from the segmented object data previously mentioned. Part of the motivation for this work is to integrate both the segmentation and rendering processes into one software application, providing a seamless transition from the segmentation tasks to the rendering and visualization tasks. Previously these tasks were accomplished on two different computer systems, windows and Linux. This transition basically limits the usefulness of the segmentation and rendering applications to those who have both computer systems readily available. The focus of this work is to create custom Matlab image processing algorithms for object rendering and visualization, and merge these capabilities to the Matlab files that were developed especially for the image segmentation task. The completed Matlab application will contain both the segmentation and rendering processes in a single graphical user interface, or GUI. This process for rendering three-dimensional images in Matlab requires that a sequence of two-dimensional binary images, representing a cross-sectional slice of the object, be reassembled in a 3D space, and covered with a surface. Additional segmented objects can be rendered in the same 3D space. The surface properties of each object can be varied by the user to aid in the study and analysis of the objects. This inter-active process becomes a powerful visual tool to study and understand microscopic objects.

  11. c-erbA and v-erbA modulate growth and gene expression of a mouse glial precursor cell line.

    Science.gov (United States)

    Iglesias, T; Llanos, S; López-Barahona, M; Pérez-Aranda, A; Rodríguez-Peña, A; Bernal, J; Höhne, A; Seliger, B; Muñoz, A

    1994-07-01

    The c-erbA alpha protooncogene coding for the thyroid hormone (T3) receptor (TR alpha 1) and the viral, mutated v-erbA oncogene were expressed in an immortal mouse glial cell line (B3.1) using retroviral vectors. c-erbA alpha expression led to a decrease in cell proliferation in high and low serum conditions, both in the presence and in the absence of T3. In serum-free medium, c-erbA-expressing cells (B3.1 + TR alpha 1) were completely arrested, whereas cells expressing v-erbA (B3.1 + v-erbA) showed a higher DNA synthesis rate than normal B3.1 cells. Although proliferation of all three cell types was stimulated by platelet-derived growth factor and basic fibroblast growth factor, differences were also observed in the response to these agents. B3.1 + TR alpha 1 cells were more sensitive to platelet-derived growth factor than B3.1 and B3.1 + v-erbA cells. In contrast, B3.1 cells responded to basic fibroblast growth factor better than B3.1 + TR alpha 1 or B3.1 + v-erbA cells. Insulin-like growth factor I potentiated the action of platelet-derived growth factor and basic fibroblast growth factor. Again, different responses to treatment with insulin-like growth factor I alone were observed; B3.1 + TR alpha 1 cells did not respond to it, whereas B3.1 + v-erbA cells showed a dramatic stimulation by this agent. Interestingly, in the presence of T3, the blockade in B3.1 + TR alpha 1 cell proliferation was accompanied by the down-regulation of the typical astrocytic genes, glial fibrillary acidic protein and vimentin. These hormone effects were not found in v-erbA-expressing cells. In addition, v-erbA inhibited the basal expression of the cyclic nucleotide phosphodiesterase gene, an oligodendrocytic marker.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Color-coded volume rendering for three-dimensional reconstructions of CT data

    International Nuclear Information System (INIS)

    Rieker, O.; Mildenberger, P.; Thelen, M.

    1999-01-01

    Purpose: To evaluate a technique of colored three-dimensional reconstructions without segmentation. Material and methods: Color-coded volume rendered images were reconstructed from the volume data of 25 thoracic, abdominal, musculoskeletal, and vascular helical CT scans using commercial software. The CT volume rendered voxels were encoded with color in the following manner. Opacity, hue, lightness, and chroma were assigned to each of four classes defined by CT number. Color-coded reconstructions were compared to the corresponding grey-scale coded reconstructions. Results: Color-coded volume rendering enabled realistic visualization of pathologic findings when there was sufficient difference in CT density. Segmentation was necessary in some cases to demonstrate small details in a complex volume. Conclusion: Color-coded volume rendering allowed lifelike visualisation of CT volumes without the need of segmentation in most cases. (orig.) [de

  13. Rendering Large-Scale Terrain Models and Positioning Objects in Relation to 3D Terrain

    National Research Council Canada - National Science Library

    Hittner, Brian

    2003-01-01

    .... Rendering large scale landscapes based on 3D geometry generally did not occur because the scenes generated tended to use up too much system memory and overburden 3D graphics cards with too many polygons...

  14. Flight-appropriate 3D Terrain-rendering Toolkit for Synthetic Vision, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The TerraBlocksTM 3D terrain data format and terrain-block-rendering methodology provides an enabling basis for successful commercial deployment of...

  15. Processing-in-Memory Enabled Graphics Processors for 3D Rendering

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Chenhao; Song, Shuaiwen; Wang, Jing; Zhang, Weigong; Fu, Xin

    2017-02-06

    The performance of 3D rendering of Graphics Processing Unit that convents 3D vector stream into 2D frame with 3D image effects significantly impact users’ gaming experience on modern computer systems. Due to the high texture throughput in 3D rendering, main memory bandwidth becomes a critical obstacle for improving the overall rendering performance. 3D stacked memory systems such as Hybrid Memory Cube (HMC) provide opportunities to significantly overcome the memory wall by directly connecting logic controllers to DRAM dies. Based on the observation that texel fetches significantly impact off-chip memory traffic, we propose two architectural designs to enable Processing-In-Memory based GPU for efficient 3D rendering.

  16. Flight-appropriate 3D Terrain-rendering Toolkit for Synthetic Vision, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — TerraMetrics proposes an SBIR Phase I R/R&D effort to develop a key 3D terrain-rendering technology that provides the basis for successful commercial deployment...

  17. A point-based rendering approach for real-time interaction on mobile devices

    Institute of Scientific and Technical Information of China (English)

    LIANG XiaoHui; ZHAO QinPing; HE ZhiYing; XIE Ke; LIU YuBo

    2009-01-01

    Mobile device is an Important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient.

  18. Physically-Based Rendering of Particle-Based Fluids with Light Transport Effects

    Science.gov (United States)

    Beddiaf, Ali; Babahenini, Mohamed Chaouki

    2018-03-01

    Recent interactive rendering approaches aim to efficiently produce images. However, time constraints deeply affect their output accuracy and realism (many light phenomena are poorly or not supported at all). To remedy this issue, in this paper, we propose a physically-based fluid rendering approach. First, while state-of-the-art methods focus on isosurface rendering with only two refractions, our proposal (1) considers the fluid as a heterogeneous participating medium with refractive boundaries, and (2) supports both multiple refractions and scattering. Second, the proposed solution is fully particle-based in the sense that no particles transformation into a grid is required. This interesting feature makes it able to handle many particle types (water, bubble, foam, and sand). On top of that, a medium with different fluids (color, phase function, etc.) can also be rendered.

  19. Major Deficiencies Preventing Auditors From Rendering Audit Opinions on DOD General Fund Financial Statements

    National Research Council Canada - National Science Library

    Rauu, Russell

    1995-01-01

    .... We plan to issue a similar report each year. The audit objective was to identify and summarize the major deficiencies that prevented auditors from rendering audit opinions, other than disclaimers, on Army and Air Force general fund financial...

  20. Functionality and Performance Visualization of the Distributed High Quality Volume Renderer (HVR)

    KAUST Repository

    Shaheen, Sara

    2012-07-01

    Volume rendering systems are designed to provide means to enable scientists and a variety of experts to interactively explore volume data through 3D views of the volume. However, volume rendering techniques are computationally intensive tasks. Moreover, parallel distributed volume rendering systems and multi-threading architectures were suggested as natural solutions to provide an acceptable volume rendering performance for very large volume data sizes, such as Electron Microscopy data (EM). This in turn adds another level of complexity when developing and manipulating volume rendering systems. Given that distributed parallel volume rendering systems are among the most complex systems to develop, trace and debug, it is obvious that traditional debugging tools do not provide enough support. As a consequence, there is a great demand to provide tools that are able to facilitate the manipulation of such systems. This can be achieved by utilizing the power of compute graphics in designing visual representations that reflect how the system works and that visualize the current performance state of the system.The work presented is categorized within the field of software Visualization, where Visualization is used to serve visualizing and understanding various software. In this thesis, a number of visual representations that reflect a number of functionality and performance aspects of the distributed HVR, a high quality volume renderer system that uses various techniques to visualize large volume sizes interactively. This work is provided to visualize different stages of the parallel volume rendering pipeline of HVR. This is along with means of performance analysis through a number of flexible and dynamic visualizations that reflect the current state of the system and enables manipulation of them at runtime. Those visualization are aimed to facilitate debugging, understanding and analyzing the distributed HVR.

  1. Specification and time required for the application of a lime-based render inside historic buildings

    Directory of Open Access Journals (Sweden)

    Vasco Peixoto de Freitas

    2008-01-01

    Full Text Available Intervention in ancient buildings with historical and architectural value requires traditional techniques, such as the use of lime mortars for internal and external wall renderings. In order to ensure the desired performance, these rendering mortars must be rigorously specified and quality controls have to be performed during application. The choice of mortar composition should take account of factors such as compatibility with the substrate, mechanical requirements and water behaviour. The construction schedule, which used to be considered a second order variable, nowadays plays a decisive role in the selection of the rendering technique, given its effects upon costs. How should lime-based mortars be specified? How much time is required for the application and curing of a lime-based render? This paper reflects upon the feasibility of using traditional lime mortars in three-layer renders inside churches and monasteries under adverse hygrothermal conditions and when time is critical. A case study is presented in which internal lime mortar renderings were applied in a church in Northern Portugal, where the very high relative humidity meant that several months were necessary before the drying process was complete.

  2. On-the-fly generation and rendering of infinite cities on the GPU

    KAUST Repository

    Steinberger, Markus

    2014-05-01

    In this paper, we present a new approach for shape-grammar-based generation and rendering of huge cities in real-time on the graphics processing unit (GPU). Traditional approaches rely on evaluating a shape grammar and storing the geometry produced as a preprocessing step. During rendering, the pregenerated data is then streamed to the GPU. By interweaving generation and rendering, we overcome the problems and limitations of streaming pregenerated data. Using our methods of visibility pruning and adaptive level of detail, we are able to dynamically generate only the geometry needed to render the current view in real-time directly on the GPU. We also present a robust and efficient way to dynamically update a scene\\'s derivation tree and geometry, enabling us to exploit frame-to-frame coherence. Our combined generation and rendering is significantly faster than all previous work. For detailed scenes, we are capable of generating geometry more rapidly than even just copying pregenerated data from main memory, enabling us to render cities with thousands of buildings at up to 100 frames per second, even with the camera moving at supersonic speed. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  3. Using neutrosophic graph cut segmentation algorithm for qualified rendering image selection in thyroid elastography video.

    Science.gov (United States)

    Guo, Yanhui; Jiang, Shuang-Quan; Sun, Baiqing; Siuly, Siuly; Şengür, Abdulkadir; Tian, Jia-Wei

    2017-12-01

    Recently, elastography has become very popular in clinical investigation for thyroid cancer detection and diagnosis. In elastogram, the stress results of the thyroid are displayed using pseudo colors. Due to variation of the rendering results in different frames, it is difficult for radiologists to manually select the qualified frame image quickly and efficiently. The purpose of this study is to find the qualified rendering result in the thyroid elastogram. This paper employs an efficient thyroid ultrasound image segmentation algorithm based on neutrosophic graph cut to find the qualified rendering images. Firstly, a thyroid ultrasound image is mapped into neutrosophic set, and an indeterminacy filter is constructed to reduce the indeterminacy of the spatial and intensity information in the image. A graph is defined on the image and the weight for each pixel is represented using the value after indeterminacy filtering. The segmentation results are obtained using a maximum-flow algorithm on the graph. Then the anatomic structure is identified in thyroid ultrasound image. Finally the rendering colors on these anatomic regions are extracted and validated to find the frames which satisfy the selection criteria. To test the performance of the proposed method, a thyroid elastogram dataset is built and totally 33 cases were collected. An experienced radiologist manually evaluates the selection results of the proposed method. Experimental results demonstrate that the proposed method finds the qualified rendering frame with 100% accuracy. The proposed scheme assists the radiologists to diagnose the thyroid diseases using the qualified rendering images.

  4. On-the-fly generation and rendering of infinite cities on the GPU

    KAUST Repository

    Steinberger, Markus; Kenzel, Michael; Kainz, Bernhard K.; Wonka, Peter; Schmalstieg, Dieter

    2014-01-01

    In this paper, we present a new approach for shape-grammar-based generation and rendering of huge cities in real-time on the graphics processing unit (GPU). Traditional approaches rely on evaluating a shape grammar and storing the geometry produced as a preprocessing step. During rendering, the pregenerated data is then streamed to the GPU. By interweaving generation and rendering, we overcome the problems and limitations of streaming pregenerated data. Using our methods of visibility pruning and adaptive level of detail, we are able to dynamically generate only the geometry needed to render the current view in real-time directly on the GPU. We also present a robust and efficient way to dynamically update a scene's derivation tree and geometry, enabling us to exploit frame-to-frame coherence. Our combined generation and rendering is significantly faster than all previous work. For detailed scenes, we are capable of generating geometry more rapidly than even just copying pregenerated data from main memory, enabling us to render cities with thousands of buildings at up to 100 frames per second, even with the camera moving at supersonic speed. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  5. Platelet-rich plasma stimulated by pulse electric fields: Platelet activation, procoagulant markers, growth factor release and cell proliferation.

    Science.gov (United States)

    Frelinger, A L; Torres, A S; Caiafa, A; Morton, C A; Berny-Lang, M A; Gerrits, A J; Carmichael, S L; Neculaes, V B; Michelson, A D

    2016-01-01

    Therapeutic use of activated platelet-rich plasma (PRP) has been explored for wound healing, hemostasis and antimicrobial wound applications. Pulse electric field (PEF) stimulation may provide more consistent platelet activation and avoid complications associated with the addition of bovine thrombin, the current state of the art ex vivo activator of therapeutic PRP. The aim of this study was to compare the ability of PEF, bovine thrombin and thrombin receptor activating peptide (TRAP) to activate human PRP, release growth factors and induce cell proliferation in vitro. Human PRP was prepared in the Harvest SmartPreP2 System and treated with vehicle, PEF, bovine thrombin, TRAP or Triton X-100. Platelet activation and procoagulant markers and microparticle generation were measured by flow cytometry. Released growth factors were measured by ELISA. The releasates were tested for their ability to stimulate proliferation of human epithelial cells in culture. PEF produced more platelet-derived microparticles, P-selectin-positive particles and procoagulant annexin V-positive particles than bovine thrombin or TRAP. These differences were associated with higher levels of released epidermal growth factor after PEF than after bovine thrombin or TRAP but similar levels of platelet-derived, vascular-endothelial, and basic fibroblast growth factors, and platelet factor 4. Supernatant from PEF-treated platelets significantly increased cell proliferation compared to plasma. In conclusion, PEF treatment of fresh PRP results in generation of microparticles, exposure of prothrombotic platelet surfaces, differential release of growth factors compared to bovine thrombin and TRAP and significant cell proliferation. These results, together with PEF's inherent advantages, suggest that PEF may be a superior alternative to bovine thrombin activation of PRP for therapeutic applications.

  6. Human platelet lysate as a promising growth-stimulating additive for culturing of stem cells and other cell types.

    Science.gov (United States)

    Shanskii, Ya D; Sergeeva, N S; Sviridova, I K; Kirakozov, M S; Kirsanova, V A; Akhmedova, S A; Antokhin, A I; Chissov, V I

    2013-11-01

    We compared the composition and biological activity of fetal calf serum and platelet lysate from donor platelet concentrate. In platelet lysate, the concentrations of alkaline phosphatase, lactate dehydrogenase, creatinine, and mineral metabolism parameters were lower, while parameters of lipid and protein metabolism were higher than in fetal calf serum. The concentrations of growth factors (platelet-derived (AA, AB, BB), vascular endothelial, insulin-like, and transforming growth factor β) in platelet lysate 1.7-148.7-fold surpassed the corresponding parameters in fetal calf serum. After replacement of fetal calf serum with platelet lysate in the culture medium (0, 25, 50, 75, and 100%), the count of multipotent mesenchymal stromal cells on day 7 (in comparison with day 1) increased by 154.8, 206.6, 228.2, 367.7, and 396.5%, respectively. Thus, platelet lysate can be an adequate non-xenogenic alternative for fetal calf serum.

  7. Distinct phosphotyrosines on a growth factor receptor bind to specific molecules that mediate different signaling pathways.

    Science.gov (United States)

    Fantl, W J; Escobedo, J A; Martin, G A; Turck, C W; del Rosario, M; McCormick, F; Williams, L T

    1992-05-01

    The receptor for platelet-derived growth factor (PDGF) binds two proteins containing SH2 domains, GTPase activating protein (GAP) and phosphatidylinositol 3-kinase (PI3-kinase). The sites on the receptor that mediate this interaction were identified by using phosphotyrosine-containing peptides representing receptor sequences to block specifically binding of either PI3-kinase or GAP. These results suggested that PI3-kinase binds two phosphotyrosine residues, each located in a 5 aa motif with an essential methionine at the fourth position C-terminal to the tyrosine. Point mutations at these sites caused a selective elimination of PI3-kinase binding and loss of PDGF-stimulated DNA synthesis. Mutation of the binding site for GAP prevented the receptor from associating with or phosphorylating GAP, but had no effect on PI3-kinase binding and little effect on DNA synthesis. Therefore, GAP and PI3-kinase interact with the receptor by binding to different phosphotyrosine-containing sequence motifs.

  8. Real-Time Location-Based Rendering of Urban Underground Pipelines

    Directory of Open Access Journals (Sweden)

    Wei Li

    2018-01-01

    Full Text Available The concealment and complex spatial relationships of urban underground pipelines present challenges in managing them. Recently, augmented reality (AR has been a hot topic around the world, because it can enhance our perception of reality by overlaying information about the environment and its objects onto the real world. Using AR, underground pipelines can be displayed accurately, intuitively, and in real time. We analyzed the characteristics of AR and their application in underground pipeline management. We mainly focused on the AR pipeline rendering procedure based on the BeiDou Navigation Satellite System (BDS and simultaneous localization and mapping (SLAM technology. First, in aiming to improve the spatial accuracy of pipeline rendering, we used differential corrections received from the Ground-Based Augmentation System to compute the precise coordinates of users in real time, which helped us accurately retrieve and draw pipelines near the users, and by scene recognition the accuracy can be further improved. Second, in terms of pipeline rendering, we used Visual-Inertial Odometry (VIO to track the rendered objects and made some improvements to visual effects, which can provide steady dynamic tracking of pipelines even in relatively markerless environments and outdoors. Finally, we used the occlusion method based on real-time 3D reconstruction to realistically express the immersion effect of underground pipelines. We compared our methods to the existing methods and concluded that the method proposed in this research improves the spatial accuracy of pipeline rendering and the portability of the equipment. Moreover, the updating of our rendering procedure corresponded with the moving of the user’s location, thus we achieved a dynamic rendering of pipelines in the real environment.

  9. 3-D volume rendering visualization for calculated distributions of diesel spray; Diesel funmu kyodo suchi keisan kekka no sanjigen volume rendering hyoji

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizaki, T; Imanishi, H; Nishida, K; Yamashita, H; Hiroyasu, H; Kaneda, K [Hiroshima University, Hiroshima (Japan)

    1997-10-01

    Three dimensional visualization technique based on volume rendering method has been developed in order to translate calculated results of diesel combustion simulation into realistically spray and flame images. This paper presents an overview of diesel combustion model which has been developed at Hiroshima University, a description of the three dimensional visualization technique, and some examples of spray and flame image generated by this visualization technique. 8 refs., 8 figs., 1 tab.

  10. Nonfeed application of rendered animal proteins for microbial production of eicosapentaenoic acid by the fungus Pythium irregulare.

    Science.gov (United States)

    Liang, Yi; Garcia, Rafael A; Piazza, George J; Wen, Zhiyou

    2011-11-23

    Rendered animal proteins are well suited for animal nutrition applications, but the market is maturing, and there is a need to develop new uses for these products. The objective of this study is to explore the possibility of using animal proteins as a nutrient source for microbial production of omega-3 polyunsaturated fatty acids by the microalga Schizochytrium limacinum and the fungus Pythium irregulare. To be absorbed by the microorganisms, the proteins needed to be hydrolyzed into small peptides and free amino acids. The utility of the protein hydrolysates for microorganisms depended on the hydrolysis method used and the type of microorganism. The enzymatic hydrolysates supported better cell growth performance than the alkali hydrolysates did. P. irregulare displayed better overall growth performance on the experimental hydrolysates compared to S. limacinum. When P. irregulare was grown in medium containing 10 g/L enzymatic hydrolysate derived from meat and bone meal or feather meal, the performance of cell growth, lipid synthesis, and omega-3 fatty acid production was comparable to the that of culture using commercial yeast extract. The fungal biomass derived from the animal proteins had 26-29% lipid, 32-34% protein, 34-39% carbohydrate, and industrial microorganisms which can produce omega-3 fatty acids for making omega-3-fortified foods or feeds.

  11. A cache-friendly sampling strategy for texture-based volume rendering on GPU

    Directory of Open Access Journals (Sweden)

    Junpeng Wang

    2017-06-01

    Full Text Available The texture-based volume rendering is a memory-intensive algorithm. Its performance relies heavily on the performance of the texture cache. However, most existing texture-based volume rendering methods blindly map computational resources to texture memory and result in incoherent memory access patterns, causing low cache hit rates in certain cases. The distance between samples taken by threads of an atomic scheduling unit (e.g. a warp of 32 threads in CUDA of the GPU is a crucial factor that affects the texture cache performance. Based on this fact, we present a new sampling strategy, called Warp Marching, for the ray-casting algorithm of texture-based volume rendering. The effects of different sample organizations and different thread-pixel mappings in the ray-casting algorithm are thoroughly analyzed. Also, a pipeline manner color blending approach is introduced and the power of warp-level GPU operations is leveraged to improve the efficiency of parallel executions on the GPU. In addition, the rendering performance of the Warp Marching is view-independent, and it outperforms existing empty space skipping techniques in scenarios that need to render large dynamic volumes in a low resolution image. Through a series of micro-benchmarking and real-life data experiments, we rigorously analyze our sampling strategies and demonstrate significant performance enhancements over existing sampling methods.

  12. Evaluation and Improvement of the CIE Metameric and Colour Rendering Index

    Directory of Open Access Journals (Sweden)

    Radovan Slavuj

    2015-12-01

    Full Text Available All artificial light sources are intended to simulate daylight and its properties of color rendering or ability of colour discrimination. Two indices, defined by the CIE, are used to quantify quality of the artificial light sources. First is Color Rendering Index which quantifies ability of light sources to render colours and other is the Metemerism Index which describes metamerism potential of given light source. Calculation of both indices are defined by CIE and has been a subject of discussion and change in past. In this work particularly, the problem of sample number and type used in calculation is addressed here and evaluated. It is noticed that both indices depends on the choice and sample number and that they should be determined based on application.

  13. The Visualization Toolkit (VTK): Rewriting the rendering code for modern graphics cards

    Science.gov (United States)

    Hanwell, Marcus D.; Martin, Kenneth M.; Chaudhary, Aashish; Avila, Lisa S.

    2015-09-01

    The Visualization Toolkit (VTK) is an open source, permissively licensed, cross-platform toolkit for scientific data processing, visualization, and data analysis. It is over two decades old, originally developed for a very different graphics card architecture. Modern graphics cards feature fully programmable, highly parallelized architectures with large core counts. VTK's rendering code was rewritten to take advantage of modern graphics cards, maintaining most of the toolkit's programming interfaces. This offers the opportunity to compare the performance of old and new rendering code on the same systems/cards. Significant improvements in rendering speeds and memory footprints mean that scientific data can be visualized in greater detail than ever before. The widespread use of VTK means that these improvements will reap significant benefits.

  14. Reflection curves—new computation and rendering techniques

    Directory of Open Access Journals (Sweden)

    Dan-Eugen Ulmet

    2004-05-01

    Full Text Available Reflection curves on surfaces are important tools for free-form surface interrogation. They are essential for industrial 3D CAD/CAM systems and for rendering purposes. In this note, new approaches regarding the computation and rendering of reflection curves on surfaces are introduced. These approaches are designed to take the advantage of the graphics libraries of recent releases of commercial systems such as the OpenInventor toolkit (developed by Silicon Graphics or Matlab (developed by The Math Works. A new relation between reflection curves and contour curves is derived; this theoretical result is used for a straightforward Matlab implementation of reflection curves. A new type of reflection curves is also generated using the OpenInventor texture and environment mapping implementations. This allows the computation, rendering, and animation of reflection curves at interactive rates, which makes it particularly useful for industrial applications.

  15. Cement-Based Renders Manufactured with Phase-Change Materials: Applications and Feasibility

    Directory of Open Access Journals (Sweden)

    Luigi Coppola

    2016-01-01

    Full Text Available The paper focuses on the evaluation of the rheological and mechanical performances of cement-based renders manufactured with phase-change materials (PCM in form of microencapsulated paraffin for innovative and ecofriendly residential buildings. Specifically, cement-based renders were manufactured by incorporating different amount of paraffin microcapsules—ranging from 5% to 20% by weight with respect to binder. Specific mass, entrained or entrapped air, and setting time were evaluated on fresh mortars. Compressive strength was measured over time to evaluate the effect of the PCM addition on the hydration kinetics of cement. Drying shrinkage was also evaluated. Experimental results confirmed that the compressive strength decreases as the amount of PCM increases. Furthermore, the higher the PCM content, the higher the drying shrinkage. The results confirm the possibility of manufacturing cement-based renders containing up to 20% by weight of PCM microcapsules with respect to binder.

  16. A concept of volume rendering guided search process to analyze medical data set.

    Science.gov (United States)

    Zhou, Jianlong; Xiao, Chun; Wang, Zhiyan; Takatsuka, Masahiro

    2008-03-01

    This paper firstly presents an approach of parallel coordinates based parameter control panel (PCP). The PCP is used to control parameters of focal region-based volume rendering (FRVR) during data analysis. It uses a parallel coordinates style interface. Different rendering parameters represented with nodes on each axis, and renditions based on related parameters are connected using polylines to show dependencies between renditions and parameters. Based on the PCP, a concept of volume rendering guided search process is proposed. The search pipeline is divided into four phases. Different parameters of FRVR are recorded and modulated in the PCP during search phases. The concept shows that volume visualization could play the role of guiding a search process in the rendition space to help users to efficiently find local structures of interest. The usability of the proposed approach is evaluated to show its effectiveness.

  17. Local intelligent electronic device (IED) rendering templates over limited bandwidth communication link to manage remote IED

    Science.gov (United States)

    Bradetich, Ryan; Dearien, Jason A; Grussling, Barry Jakob; Remaley, Gavin

    2013-11-05

    The present disclosure provides systems and methods for remote device management. According to various embodiments, a local intelligent electronic device (IED) may be in communication with a remote IED via a limited bandwidth communication link, such as a serial link. The limited bandwidth communication link may not support traditional remote management interfaces. According to one embodiment, a local IED may present an operator with a management interface for a remote IED by rendering locally stored templates. The local IED may render the locally stored templates using sparse data obtained from the remote IED. According to various embodiments, the management interface may be a web client interface and/or an HTML interface. The bandwidth required to present a remote management interface may be significantly reduced by rendering locally stored templates rather than requesting an entire management interface from the remote IED. According to various embodiments, an IED may comprise an encryption transceiver.

  18. Use of volume-rendered images in registration of nuclear medicine studies

    International Nuclear Information System (INIS)

    Wallis, J.W.; Miller, T.R.; Hsu, S.S.

    1995-01-01

    A simple operator-guided alignment technique based on volume-rendered images was developed to register tomographic nuclear medicine studies. For each of 2 three-dimensional data sets to be registered, volume-rendered images were generated in 3 orthogonal projections (x,y,z) using the method of maximum-activity projection. Registration was achieved as follows: (a) One of the rendering orientations (e.g. x) was chosen for manipulation; (b) The two dimensional rendering was translated and rotated under operator control to achieve the best alignment as determined by visual assessment; (c) This rotation and translation was then applied to the underlying three-dimensional data set, with updating of the rendered images in each of the orthogonal projections; (d) Another orientation was chosen, and the process repeated. Since manipulation was performed on the small two-dimensional rendered image, feedback was instantaneous. To aid in the visual alignment, difference images and flicker images (toggling between the two data sets) were displayed. Accuracy was assessed by analysis of separate clinical data sets acquired without patient movement. After arbitrary rotation and translation of one of the two data sets, the 2 data sets were registered. Mean registration error was 0.36 pixels, corresponding to a 2.44 mm registration error. Thus, accurate registration can be achieved in under 10 minutes using this simple technique. The accuracy of registration was assessed with use of duplicate SPECT studies originating from separate reconstructions of the data from each of the detectors of a triple-head gamma camera

  19. ACCELERATION RENDERING METHOD ON RAY TRACING WITH ANGLE COMPARISON AND DISTANCE COMPARISON

    Directory of Open Access Journals (Sweden)

    Liliana liliana

    2007-01-01

    Full Text Available In computer graphics applications, to produce realistic images, a method that is often used is ray tracing. Ray tracing does not only model local illumination but also global illumination. Local illumination count ambient, diffuse and specular effects only, but global illumination also count mirroring and transparency. Local illumination count effects from the lamp(s but global illumination count effects from other object(s too. Objects that are usually modeled are primitive objects and mesh objects. The advantage of mesh modeling is various, interesting and real-like shape. Mesh contains many primitive objects like triangle or square (rare. A problem in mesh object modeling is long rendering time. It is because every ray must be checked with a lot of triangle of the mesh. Added by ray from other objects checking, the number of ray that traced will increase. It causes the increasing of rendering time. To solve this problem, in this research, new methods are developed to make the rendering process of mesh object faster. The new methods are angle comparison and distance comparison. These methods are used to reduce the number of ray checking. The rays predicted will not intersect with the mesh, are not checked weather the ray intersects the mesh. With angle comparison, if using small angle to compare, the rendering process will be fast. This method has disadvantage, if the shape of each triangle is big, some triangles will be corrupted. If the angle to compare is bigger, mesh corruption can be avoided but the rendering time will be longer than without comparison. With distance comparison, the rendering time is less than without comparison, and no triangle will be corrupted.

  20. Construction and Evaluation of an Ultra Low Latency Frameless Renderer for VR.

    Science.gov (United States)

    Friston, Sebastian; Steed, Anthony; Tilbury, Simon; Gaydadjiev, Georgi

    2016-04-01

    Latency - the delay between a user's action and the response to this action - is known to be detrimental to virtual reality. Latency is typically considered to be a discrete value characterising a delay, constant in time and space - but this characterisation is incomplete. Latency changes across the display during scan-out, and how it does so is dependent on the rendering approach used. In this study, we present an ultra-low latency real-time ray-casting renderer for virtual reality, implemented on an FPGA. Our renderer has a latency of ~1 ms from 'tracker to pixel'. Its frameless nature means that the region of the display with the lowest latency immediately follows the scan-beam. This is in contrast to frame-based systems such as those using typical GPUs, for which the latency increases as scan-out proceeds. Using a series of high and low speed videos of our system in use, we confirm its latency of ~1 ms. We examine how the renderer performs when driving a traditional sequential scan-out display on a readily available HMO, the Oculus Rift OK2. We contrast this with an equivalent apparatus built using a GPU. Using captured human head motion and a set of image quality measures, we assess the ability of these systems to faithfully recreate the stimuli of an ideal virtual reality system - one with a zero latency tracker, renderer and display running at 1 kHz. Finally, we examine the results of these quality measures, and how each rendering approach is affected by velocity of movement and display persistence. We find that our system, with a lower average latency, can more faithfully draw what the ideal virtual reality system would. Further, we find that with low display persistence, the sensitivity to velocity of both systems is lowered, but that it is much lower for ours.

  1. Concentration of platelets and growth factors in platelet-rich plasma from Goettingen minipigs.

    Science.gov (United States)

    Jungbluth, Pascal; Grassmann, Jan-Peter; Thelen, Simon; Wild, Michael; Sager, Martin; Windolf, Joachim; Hakimi, Mohssen

    2014-01-01

    In minipigs little is known about the concentration of growth factors in plasma, despite their major role in several patho-physiological processes such as healing of fractures. This prompted us to study the concentration of platelets and selected growth factors in plasma and platelet-rich plasma (PRP) preparation of sixteen Goettingen minipigs. Platelet concentrations increased significantly in PRP in comparison to native blood plasma. Generally, significant increase in the concentration of all growth factors tested was observed in the PRP in comparison to the corresponding plasma or serum. Five of the plasma samples examined contained detectable levels of bone morphogenic protein 2 (BMP-2) whereas eleven of the plasma or serum samples contained minimal amounts of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF-bb) respectively. On the other hand variable concentrations of bone morphogenic protein 7 (BMP-7) and transforming growth factor β1 (TGF-β1) were measured in all plasma samples. In contrast, all PRP samples contained significantly increased amounts of growth factors. The level of BMP-2, BMP-7, TGF-β1, VEGF and PDGF-bb increased by 17.6, 1.5, 7.1, 7.2 and 103.3 fold, in comparison to the corresponding non-enriched preparations. Moreover significant positive correlations were found between platelet count and the concentrations of BMP-2 (r=0.62, pplatelet-rich plasma of minipigs which might thus serve as a source of autologous growth factors.

  2. Organotypic Cultures of Intervertebral Disc Cells: Responses to Growth Factors and Signaling Pathways Involved

    Directory of Open Access Journals (Sweden)

    Harris Pratsinis

    2015-01-01

    Full Text Available Intervertebral disc (IVD degeneration is strongly associated with low back pain, a major cause of disability worldwide. An in-depth understanding of IVD cell physiology is required for the design of novel regenerative therapies. Accordingly, aim of this work was the study of IVD cell responses to mitogenic growth factors in a three-dimensional (3D organotypic milieu, comprising characteristic molecules of IVD’s extracellular matrix. In particular, annulus fibrosus (AF cells were cultured inside collagen type-I gels, while nucleus pulposus (NP cells in chondroitin sulfate A (CSA supplemented collagen gels, and the effects of Platelet-Derived Growth Factor (PDGF, basic Fibroblast Growth Factor (bFGF, and Insulin-Like Growth Factor-I (IGF-I were assessed. All three growth factors stimulated DNA synthesis in both AF and NP 3D cell cultures, with potencies similar to those observed previously in monolayers. CSA supplementation inhibited basal DNA synthesis rates, without affecting the response to growth factors. ERK and Akt were found to be phosphorylated following growth factor stimulation. Blockade of these two signaling pathways using pharmacologic inhibitors significantly, though not completely, inhibited growth factor-induced DNA synthesis. The proposed culture systems may prove useful for further in vitro studies aiming at future interventions for IVD regeneration.

  3. USER EVALUATION OF EIGHT LED LIGHT SOURCES WITH DIFFERENTSPECIAL COLOUR RENDERING INDICES R9

    DEFF Research Database (Denmark)

    Markvart, Jakob; Iversen, Anne; Logadóttir, Ásta

    2013-01-01

    In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...... and general colour rendering index, but with varying R9. It was found that the test subjects in general are more positive towards light sources with higher R9. The shift from a majority of negative responses to a majority of positive responses is found to occur at R9 values of ~20....

  4. Mastering Mental Ray Rendering Techniques for 3D and CAD Professionals

    CERN Document Server

    O'Connor, Jennifer

    2010-01-01

    Proven techniques for using mental ray effectively. If you're a busy artist seeking high-end results for your 3D, design, or architecture renders using mental ray, this is the perfect book for you. It distills the highly technical nature of rendering into easy-to-follow steps and tutorials that you can apply immediately to your own projects. The book uses 3ds Max and 3ds Max Design to show the integration with mental ray, but users of any 3D or CAD software can learn valuable techniques for incorporating mental ray into their pipelines.: Takes you under the hood of mental ray, a stand-alone or

  5. Towards the Availability of the Distributed Cluster Rendering System: Automatic Modeling and Verification

    DEFF Research Database (Denmark)

    Wang, Kemin; Jiang, Zhengtao; Wang, Yongbin

    2012-01-01

    , whenever the number of node-n and related parameters vary, we can create the PRISM model file rapidly and then we can use PRISM model checker to verify ralated system properties. At the end of this study, we analyzed and verified the availability distributions of the Distributed Cluster Rendering System......In this study, we proposed a Continuous Time Markov Chain Model towards the availability of n-node clusters of Distributed Rendering System. It's an infinite one, we formalized it, based on the model, we implemented a software, which can automatically model with PRISM language. With the tool...

  6. Parametric model of the scala tympani for haptic-rendered cochlear implantation.

    Science.gov (United States)

    Todd, Catherine; Naghdy, Fazel

    2005-01-01

    A parametric model of the human scala tympani has been designed for use in a haptic-rendered computer simulation of cochlear implant surgery. It will be the first surgical simulator of this kind. A geometric model of the Scala Tympani has been derived from measured data for this purpose. The model is compared with two existing descriptions of the cochlear spiral. A first approximation of the basilar membrane is also produced. The structures are imported into a force-rendering software application for system development.

  7. Deep Exemplar 2D-3D Detection by Adapting from Real to Rendered Views

    OpenAIRE

    Massa, Francisco; Russell, Bryan; Aubry, Mathieu

    2015-01-01

    This paper presents an end-to-end convolutional neural network (CNN) for 2D-3D exemplar detection. We demonstrate that the ability to adapt the features of natural images to better align with those of CAD rendered views is critical to the success of our technique. We show that the adaptation can be learned by compositing rendered views of textured object models on natural images. Our approach can be naturally incorporated into a CNN detection pipeline and extends the accuracy and speed benefi...

  8. Digital representations of the real world how to capture, model, and render visual reality

    CERN Document Server

    Magnor, Marcus A; Sorkine-Hornung, Olga; Theobalt, Christian

    2015-01-01

    Create Genuine Visual Realism in Computer Graphics Digital Representations of the Real World: How to Capture, Model, and Render Visual Reality explains how to portray visual worlds with a high degree of realism using the latest video acquisition technology, computer graphics methods, and computer vision algorithms. It explores the integration of new capture modalities, reconstruction approaches, and visual perception into the computer graphics pipeline.Understand the Entire Pipeline from Acquisition, Reconstruction, and Modeling to Realistic Rendering and ApplicationsThe book covers sensors fo

  9. Hardware-accelerated Point Generation and Rendering of Point-based Impostors

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    2005-01-01

    This paper presents a novel scheme for generating points from triangle models. The method is fast and lends itself well to implementation using graphics hardware. The triangle to point conversion is done by rendering the models, and the rendering may be performed procedurally or by a black box API....... I describe the technique in detail and discuss how the generated point sets can easily be used as impostors for the original triangle models used to create the points. Since the points reside solely in GPU memory, these impostors are fairly efficient. Source code is available online....

  10. Rendering mortars in Medina Azahara, Part II: Material characterization and alteration causes

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    1997-06-01

    Full Text Available In the present work, the depicted coat that covers some of the mortars exposed to weathering in the Medina Azahara archaeological site is .studied. That coat is characterized from the compositional and physical viewpoint and the main causes for its decay are determined. The depicted coat is formed by cal cite and iron oxides. It is quite compact and homogeneous. It is approximately 0.1 to 1 mm thick. The depicted coats supposed by lime mortars have CaCO3 deposits over polychromy rests. Depicted coats supported by gypsum mortars or mixed lime and gypsum mortars have gypsum deposits over polychromy rests. The processes of rendering mortars dissolution and the later crystallization of salts on their surface, together with biological growth, are the main causes of the decay of the depicted coats.

    En el presente trabajo se estudia la capa de policromía que recubre algunos de los morteros conservados a la intemperie en la ciudad de Medina Azahara. Dicha capa se caracteriza desde el punto de vista composicional y físico, determinándose las principales causas de su deterioro. La capa de policromía está formada por calcita y óxidos de hierro. Dicha capa es bastante homogénea y compacta. Su espesor es de 0,1 a 1 mm aproximadamente. Las capas de pintura sustentadas por morteros de cal tienen un depósito de CaCO sobre los restos de policromía. Las capas de pintura sustentadas por morteros de yeso o bastardos de cal y yeso tienen depósitos de yeso sobre los restos de policromía. Los procesos de disolución de los revocos y la posterior cristalización de las sales en su superficie, junto con la colonización biológica, son las principales causas de deterioro de la capa de policromía de su superficie.

  11. Leveraging Disturbance Observer Based Torque Control for Improved Impedance Rendering with Series Elastic Actuators

    Science.gov (United States)

    Mehling, Joshua S.; Holley, James; O'Malley, Marcia K.

    2015-01-01

    The fidelity with which series elastic actuators (SEAs) render desired impedances is important. Numerous approaches to SEA impedance control have been developed under the premise that high-precision actuator torque control is a prerequisite. Indeed, the design of an inner torque compensator has a significant impact on actuator impedance rendering. The disturbance observer (DOB) based torque control implemented in NASA's Valkyrie robot is considered here and a mathematical model of this torque control, cascaded with an outer impedance compensator, is constructed. While previous work has examined the impact a disturbance observer has on torque control performance, little has been done regarding DOBs and impedance rendering accuracy. Both simulation and a series of experiments are used to demonstrate the significant improvements possible in an SEA's ability to render desired dynamic behaviors when utilizing a DOB. Actuator transparency at low impedances is improved, closed loop hysteresis is reduced, and the actuator's dynamic response to both commands and interaction torques more faithfully matches that of the desired model. All of this is achieved by leveraging DOB based control rather than increasing compensator gains, thus making improved SEA impedance control easier to achieve in practice.

  12. Photometric and Colorimeric Comparison of HDR and Spctrally Resolved Rendering Images

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Soreze, Thierry Silvio Claude; Thorseth, Anders

    2017-01-01

    In this paper, we will demonstrate a comparison between measured colorimetric images, and simulated images from a physics based rendering engine. The colorimetric images are high dynamic range (HDR) and taken with a luminance and colour camera mounted on a goniometer. For the comparison, we have ...

  13. GRAPHICS-IMAGE MIXED METHOD FOR LARGE-SCALE BUILDINGS RENDERING

    Directory of Open Access Journals (Sweden)

    Y. Zhou

    2018-05-01

    Full Text Available Urban 3D model data is huge and unstructured, LOD and Out-of-core algorithm are usually used to reduce the amount of data that drawn in each frame to improve the rendering efficiency. When the scene is large enough, even the complex optimization algorithm is difficult to achieve better results. Based on the traditional study, a novel idea was developed. We propose a graphics and image mixed method for large-scale buildings rendering. Firstly, the view field is divided into several regions, the graphics-image mixed method used to render the scene on both screen and FBO, then blending the FBO with scree. The algorithm is tested on the huge CityGML model data in the urban areas of New York which contained 188195 public building models, and compared with the Cesium platform. The experiment result shows the system was running smoothly. The experimental results confirm that the algorithm can achieve more massive building scene roaming under the same hardware conditions, and can rendering the scene without vision loss.

  14. Advanced Audiovisual Rendering, Gesture-Based Interaction and Distributed Delivery for Immersive and Interactive Media Services

    NARCIS (Netherlands)

    Niamut, O.A.; Kochale, A.; Ruiz Hidalgo, J.; Macq, J-F.; Kienast, G.

    2011-01-01

    The media industry is currently being pulled in the often-opposing directions of increased realism (high resolution, stereoscopic, large screen) and personalisation (selection and control of content, availability on many devices). A capture, production, delivery and rendering system capable of

  15. An economic analysis of localized pollution: rendering emissions in a residential setting

    Science.gov (United States)

    J. Michael Bowker; H.F. MacDonald

    1991-01-01

    The contingent value method is employed to estimate economic damages to households resulting from rendering plant emissions in a small town. Household willingness to accept (WTA) and willingness to pay (WTP) are estimated individually and in aggregate. The influence of household characteristics on WTP and WTA is examined via regression models. The perception of health...

  16. 3D-TV Rendering on a Multiprocessor System on a Chip

    NARCIS (Netherlands)

    Van Eijndhoven, J.T.J.; Li, X.

    2006-01-01

    This thesis focuses on the issue of mapping 3D-TV rendering applications to a multiprocessor platform. The target platform aims to address tomorrow's multi-media consumer market. The prototype chip, called Wasabi, contains a set of TriMedia processors that communicate viaa shared memory, fast

  17. Dynamic Resolution in GPU-Accelerated Volume Rendering to Autostereoscopic Multiview Lenticular Displays

    Directory of Open Access Journals (Sweden)

    Daniel Ruijters

    2008-09-01

    Full Text Available The generation of multiview stereoscopic images of large volume rendered data demands an enormous amount of calculations. We propose a method for hardware accelerated volume rendering of medical data sets to multiview lenticular displays, offering interactive manipulation throughout. The method is based on buffering GPU-accelerated direct volume rendered visualizations of the individual views from their respective focal spot positions, and composing the output signal for the multiview lenticular screen in a second pass. This compositing phase is facilitated by the fact that the view assignment per subpixel is static, and therefore can be precomputed. We decoupled the resolution of the individual views from the resolution of the composited signal, and adjust the resolution on-the-fly, depending on the available processing resources, in order to maintain interactive refresh rates. The optimal resolution for the volume rendered views is determined by means of an analysis of the lattice of the output signal for the lenticular screen in the Fourier domain.

  18. An Extension of Fourier-Wavelet Volume Rendering by View Interpolation

    NARCIS (Netherlands)

    Westenberg, Michel A.; Roerdink, Jos B.T.M.

    2001-01-01

    This paper describes an extension to Fourier-wavelet volume rendering (FWVR), which is a Fourier domain implementation of the wavelet X-ray transform. This transform combines integration along the line of sight with a simultaneous 2-D wavelet transform in the view plane perpendicular to this line.

  19. User evaluation of eight led light sources with different special colour rendering indices R9

    DEFF Research Database (Denmark)

    Markvart, Jakob; Iversen, Anne; Logadottir, Asta

    2013-01-01

    In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...

  20. Uniform illumination rendering using an array of LEDs: a signal processing perspective

    NARCIS (Netherlands)

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.; Linnartz, J.P.M.G.; Rietman, R.

    2009-01-01

    An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic

  1. Interactive dual-volume rendering visualization with real-time fusion and transfer function enhancement

    Science.gov (United States)

    Macready, Hugh; Kim, Jinman; Feng, David; Cai, Weidong

    2006-03-01

    Dual-modality imaging scanners combining functional PET and anatomical CT constitute a challenge in volumetric visualization that can be limited by the high computational demand and expense. This study aims at providing physicians with multi-dimensional visualization tools, in order to navigate and manipulate the data running on a consumer PC. We have maximized the utilization of pixel-shader architecture of the low-cost graphic hardware and the texture-based volume rendering to provide visualization tools with high degree of interactivity. All the software was developed using OpenGL and Silicon Graphics Inc. Volumizer, tested on a Pentium mobile CPU on a PC notebook with 64M graphic memory. We render the individual modalities separately, and performing real-time per-voxel fusion. We designed a novel "alpha-spike" transfer function to interactively identify structure of interest from volume rendering of PET/CT. This works by assigning a non-linear opacity to the voxels, thus, allowing the physician to selectively eliminate or reveal information from the PET/CT volumes. As the PET and CT are rendered independently, manipulations can be applied to individual volumes, for instance, the application of transfer function to CT to reveal the lung boundary while adjusting the fusion ration between the CT and PET to enhance the contrast of a tumour region, with the resultant manipulated data sets fused together in real-time as the adjustments are made. In addition to conventional navigation and manipulation tools, such as scaling, LUT, volume slicing, and others, our strategy permits efficient visualization of PET/CT volume rendering which can potentially aid in interpretation and diagnosis.

  2. Validation of Thermal Lethality against Salmonella enterica in Poultry Offal during Rendering.

    Science.gov (United States)

    Jones-Ibarra, Amie-Marie; Acuff, Gary R; Alvarado, Christine Z; Taylor, T Matthew

    2017-09-01

    Recent outbreaks of human disease following contact with companion animal foods cross-contaminated with enteric pathogens, such as Salmonella enterica, have resulted in increased concern regarding the microbiological safety of animal foods. Additionally, the U.S. Food and Drug Administration Food Safety Modernization Act and its implementing rules have stipulated the implementation of current good manufacturing practices and food safety preventive controls for livestock and companion animal foods. Animal foods and feeds are sometimes formulated to include thermally rendered animal by-product meals. The objective of this research was to determine the thermal inactivation of S. enterica in poultry offal during rendering at differing temperatures. Raw poultry offal was obtained from a commercial renderer and inoculated with a mixture of Salmonella serovars Senftenberg, Enteritidis, and Gallinarum (an avian pathogen) prior to being subjected to heating at 150, 155, or 160°F (65.5, 68.3, or 71.1°C) for up to 15 min. Following heat application, surviving Salmonella bacteria were enumerated. Mean D-values for the Salmonella cocktail at 150, 155, and 160°F were 0.254 ± 0.045, 0.172 ± 0.012, and 0.086 ± 0.004 min, respectively, indicative of increasing susceptibility to increased application of heat during processing. The mean thermal process constant (z-value) was 21.948 ± 3.87°F. Results indicate that a 7.0-log-cycle inactivation of Salmonella may be obtained from the cumulative lethality encountered during the heating come-up period and subsequent rendering of raw poultry offal at temperatures not less than 150°F. Current poultry rendering procedures are anticipated to be effective for achieving necessary pathogen control when completed under sanitary conditions.

  3. Developing a Tile-Based Rendering Method to Improve Rendering Speed of 3D Geospatial Data with HTML5 and WebGL

    Directory of Open Access Journals (Sweden)

    Seokchan Kang

    2017-01-01

    Full Text Available A dedicated plug-in has been installed to visualize three-dimensional (3D city modeling spatial data in web-based applications. However, plug-in methods are gradually becoming obsolete, owing to their limited performance with respect to installation errors, unsupported cross-browsers, and security vulnerability. Particularly, in 2015, the NPAPI service was terminated in most existing web browsers except Internet Explorer. To overcome these problems, the HTML5/WebGL (next-generation web standard, confirmed in October 2014 technology emerged. In particular, WebGL is able to display 3D spatial data without plug-ins in browsers. In this study, we attempted to identify the requirements and limitations of displaying 3D city modeling spatial data using HTML5/WebGL, and we propose alternative ways based on the bin-packing algorithm that aggregates individual 3D city modeling data including buildings in tile units. The proposed method reduces the operational complexity and the number and volume of transmissions required for rendering processing to improve the speed of 3D data rendering. The proposed method was validated on real data for evaluating its effectiveness in 3D visualization of city modeling data in web-based applications.

  4. VIDEO ANIMASI 3D PENGENALAN RUMAH ADAT DAN ALAT MUSIK KEPRI DENGAN MENGUNAKAN TEKNIK RENDER CEL-SHADING

    OpenAIRE

    Jianfranco Irfian Asnawi; Afdhol Dzikri

    2016-01-01

    Animasi ini berjudul "video animasi 3D rumah adat dan alat musik Kepulauan Riau dengan menggunakan teknik render cel-shading" merupakan video yang bertujuan memperkenalkan alat-alat musik yang berasal dari kepulauan riau, Animasi ini akan diterapkan dengan menggunakan teknik render cel-shading. Cel-shading adalah teknik render yang menampilkan grafik 3D yang menyerupai gambar tangan, seperti gambar komik dan kartun. Teknik ini juga sudah di terapkan dalam game 3D yang ternyata menarik banyak ...

  5. Custom OpenStreetMap Rendering – OpenTrackMap Experience

    Directory of Open Access Journals (Sweden)

    Radek Bartoň

    2010-02-01

    Full Text Available After 5 years of its existence, the OpenSteetMap [1] is becoming to be an important and valuable source of a geographic data for all people on the world. Although initially targeted to provide a map of cities for routing services, it can be exploited to other and often unexpected purposes. Such an utilization is an effort to map a network of hiking tracks of the Czech Tourist Club [2].  To support and apply this endeavour, the OpenTrackMap [3] project was started. Its aim is to primarily provide a customized rendering style for Mapnik renderer which emphasizes map features important to tourists and displays a layer with hiking tracks. This article presents obstacles which such project must face and it can be used as a tutorial for other projects of similar type.

  6. Rendering LGBTQ+ Visible in Nursing: Embodying the Philosophy of Caring Science.

    Science.gov (United States)

    Goldberg, Lisa; Rosenburg, Neal; Watson, Jean

    2017-06-01

    Although health care institutions continue to address the importance of diversity initiatives, the standard(s) for treatment remain historically and institutionally grounded in a sociocultural privileging of heterosexuality. As a result, lesbian, gay, bisexual, transgender, and queer (LGBTQ+) communities in health care remain largely invisible. This marked invisibility serves as a call to action, a renaissance of thinking within redefined boundaries and limitations. We must therefore refocus our habits of attention on the wholeness of persons and the diversity of their storied experiences as embodied through contemporary society. By rethinking current understandings of LGBTQ+ identities through innovative representation(s) of the media, music industry, and pop culture within a caring science philosophy, nurses have a transformative opportunity to render LGBTQ+ visible and in turn render a transformative opportunity for themselves.

  7. 3D virtual rendering in thoracoscopic treatment of congenital malformation of the lung

    Directory of Open Access Journals (Sweden)

    Destro F.

    2013-10-01

    Full Text Available Introduction: Congenital malformations of the lung (CML are rare but potentially dangerous congenital malformations. Their identification is important in order to define the most appropriate management. Materials and methods: We retrospectively reviewed data from 37 patients affected by CML treated in our Pediatric Surgery Unit in the last four years with minimally invasive surgery (MIS. Results: Prenatal diagnosis was possible in 26/37 patients. Surgery was performed in the first month of life in 3 symptomatic patients and between 6 and 12 months in the others. All patients underwent radiological evaluation prior to thoracoscopic surgery. Images collected were reconstructed using the VR render software. Discussion and conclusions: Volume rendering gives high anatomical resolution and it can be useful to guide the surgical procedure. Thoracoscopy should be the technique of choice because it is safe, effective and feasible. Furthermore it has the benefit of a minimal access technique and it can be easily performed in children.

  8. Volume-Rendered 3D Display Of MR Angiograms in the Diagnosis of Cerebral Arteriovenous Malformations

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, K.; Katase, S.; Hachiya, J. [Kyorin Univ. School of Medicine, Tokyo (Japan). Dept. of Radiology; Shiokawa, Y. [Kyorin Univ. School of Medicine, Tokyo (Japan). Dept. of Neurosurgery

    2003-11-01

    Purpose: To determine whether application of a volume-rendered display of 3D time-of-flight (TOF) MR angiography could assist the diagnosis of cerebral arteriovenous malformations (AVMs). Material and Methods: Volume-rendered 3D images of postcontrast 3D time-of-flight MR angiography were compared with conventional angiograms in 12 patients. The correlation between the 3D images and the operative findings was also analyzed in 5 patients. Results: The 3D-displayed images showed all of the feeders and drainers in 10 and 9 patients, respectively. In all patients, the nidus was three-dimensionally visualized. In 3 patients with hematomas, the relationship between the hematoma and the AVM was well demonstrated. The 3D images corresponded well with the operative findings in the 5 patients. Conclusion: This method is of help in assessing the relationship between the components of an AVM as well as that between an AVM and an associated hematoma.

  9. Volume-Rendered 3D Display Of MR Angiograms in the Diagnosis of Cerebral Arteriovenous Malformations

    International Nuclear Information System (INIS)

    Tsuchiya, K.; Katase, S.; Hachiya, J.; Shiokawa, Y.

    2003-01-01

    Purpose: To determine whether application of a volume-rendered display of 3D time-of-flight (TOF) MR angiography could assist the diagnosis of cerebral arteriovenous malformations (AVMs). Material and Methods: Volume-rendered 3D images of postcontrast 3D time-of-flight MR angiography were compared with conventional angiograms in 12 patients. The correlation between the 3D images and the operative findings was also analyzed in 5 patients. Results: The 3D-displayed images showed all of the feeders and drainers in 10 and 9 patients, respectively. In all patients, the nidus was three-dimensionally visualized. In 3 patients with hematomas, the relationship between the hematoma and the AVM was well demonstrated. The 3D images corresponded well with the operative findings in the 5 patients. Conclusion: This method is of help in assessing the relationship between the components of an AVM as well as that between an AVM and an associated hematoma

  10. Pyrite: A blender plugin for visualizing molecular dynamics simulations using industry-standard rendering techniques.

    Science.gov (United States)

    Rajendiran, Nivedita; Durrant, Jacob D

    2018-05-05

    Molecular dynamics (MD) simulations provide critical insights into many biological mechanisms. Programs such as VMD, Chimera, and PyMOL can produce impressive simulation visualizations, but they lack many advanced rendering algorithms common in the film and video-game industries. In contrast, the modeling program Blender includes such algorithms but cannot import MD-simulation data. MD trajectories often require many gigabytes of memory/disk space, complicating Blender import. We present Pyrite, a Blender plugin that overcomes these limitations. Pyrite allows researchers to visualize MD simulations within Blender, with full access to Blender's cutting-edge rendering techniques. We expect Pyrite-generated images to appeal to students and non-specialists alike. A copy of the plugin is available at http://durrantlab.com/pyrite/, released under the terms of the GNU General Public License Version 3. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Moisture transport properties of brick – comparison of exposed, impregnated and rendered brick

    DEFF Research Database (Denmark)

    Hansen, Tessa Kvist; Bjarløv, Søren Peter; Peuhkuri, Ruut

    2016-01-01

    In regards to internal insulation of preservation worthy brick façades, external moisture sources, such as wind-driven rain exposure, inevitably has an impact on moisture conditions within the masonry construction. Surface treatments, such as hydrophobation or render, may remedy the impacts...... of external moisture. In the present paper the surface absorption of liquid water on masonry façades of untreated, hydrophobated and rendered brick, are determined experimentally and compared. The experimental work focuses on methods that can be applied on-site, Karsten tube measurements. These measurements...... are supplemented with results from laboratory measurements of water absorption coefficient by partial immersion. Based on obtained measurement results, simulations are made with external liquid water loads for determination of moisture conditions within the masonry of different surface treatments. Experimental...

  12. Waqf as a Tool for Rendering Social Welfare Services in the Social Entrepreneurship Context

    Directory of Open Access Journals (Sweden)

    Md. Mahmudul Alam

    2018-01-01

    Full Text Available The concept of Islamic entrepreneurship centers on ensuring community well-being as the priority, which is one of the important objectives (Maqasid of the Islamic Shari’ah. Historically, waqf played a significant role in the Islamic economic system, particularly in rendering exemplary welfare services in the areas of healthcare, education, social welfare, environmental, and other community-based programs. However, only a few success stories in recent history have institutionally utilized the properties of waqf under proper management to achieve its substantial objectives. This study uses the literature review as basis to analyze the reasons behind the successful utilization of waqf as an effective tool to ensure social welfare services in the past, as well as how this model can be replicated by considering current contexts. This study will assist Islamic valuecentric entrepreneurs, regulatory authorities, investors, and researchers to gain an overall insight into the potentials of waqf as a tool for rendering commendable social welfare services.

  13. Apparatus for rendering at least a portion of a device inoperable and related methods

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Michael A.; Steffler, Eric D.; Hartenstein, Steven D.; Wallace, Ronald S.

    2016-11-08

    Apparatus for rendering at least a portion of a device inoperable may include a containment structure having a first compartment that is configured to receive a device therein and a movable member configured to receive a cartridge having reactant material therein. The movable member is configured to be inserted into the first compartment of the containment structure and to ignite the reactant material within the cartridge. Methods of rendering at least a portion of a device inoperable may include disposing the device into the first compartment of the containment structure, inserting the movable member into the first compartment of the containment structure, igniting the reactant material in the cartridge, and expelling molten metal onto the device.

  14. Subsurface Scattering-Based Object Rendering Techniques for Real-Time Smartphone Games

    Directory of Open Access Journals (Sweden)

    Won-Sun Lee

    2014-01-01

    Full Text Available Subsurface scattering that simulates the path of a light through the material in a scene is one of the advanced rendering techniques in the field of computer graphics society. Since it takes a number of long operations, it cannot be easily implemented in real-time smartphone games. In this paper, we propose a subsurface scattering-based object rendering technique that is optimized for smartphone games. We employ our subsurface scattering method that is utilized for a real-time smartphone game. And an example game is designed to validate how the proposed method can be operated seamlessly in real time. Finally, we show the comparison results between bidirectional reflectance distribution function, bidirectional scattering distribution function, and our proposed subsurface scattering method on a smartphone game.

  15. A Semi-automated Approach to Improve the Efficiency of Medical Imaging Segmentation for Haptic Rendering.

    Science.gov (United States)

    Banerjee, Pat; Hu, Mengqi; Kannan, Rahul; Krishnaswamy, Srinivasan

    2017-08-01

    The Sensimmer platform represents our ongoing research on simultaneous haptics and graphics rendering of 3D models. For simulation of medical and surgical procedures using Sensimmer, 3D models must be obtained from medical imaging data, such as magnetic resonance imaging (MRI) or computed tomography (CT). Image segmentation techniques are used to determine the anatomies of interest from the images. 3D models are obtained from segmentation and their triangle reduction is required for graphics and haptics rendering. This paper focuses on creating 3D models by automating the segmentation of CT images based on the pixel contrast for integrating the interface between Sensimmer and medical imaging devices, using the volumetric approach, Hough transform method, and manual centering method. Hence, automating the process has reduced the segmentation time by 56.35% while maintaining the same accuracy of the output at ±2 voxels.

  16. A Practical Framework for Sharing and Rendering Real-World Bidirectional Scattering Distribution Functions

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Greg [Anywhere Software, Albany, CA (United States); Kurt, Murat [International Computer Institute, Ege University (Turkey); Bonneel, Nicolas [Harvard Univ., Cambridge, MA (United States)

    2012-09-30

    The utilization of real-world materials has been hindered by a lack of standards for sharing and interpreting measured data. This paper presents an XML representation and an Open Source C library to support bidirectional scattering distribution functions (BSDFs) in data-driven lighting simulation and rendering applications.The library provides for the efficient representation, query, and Monte Carlo sampling of arbitrary BSDFs in amodel-free framework. Currently, we support two BSDF data representations: one using a fixed subdivision of thehemisphere, and one with adaptive density. The fixed type has advantages for certain matrix operations, while theadaptive type can more accurately represent highly peaked data. We discuss advanced methods for data-drivenBSDF rendering for both types, including the proxy of detailed geometry to enhance appearance and accuracy.We also present an advanced interpolation method to reduce measured data into these standard representations.We end with our plan for future extensions and sharing of BSDF data.

  17. Detection of Prion Proteins and TSE Infectivity in the Rendering and Biodiesel Manufacture Processes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.; Keller, B.; Oleschuk, R. [Queen' s University, Kingston, Ontario (Canada)

    2007-03-15

    This paper addresses emerging issues related to monitoring prion proteins and TSE infectivity in the products and waste streams of rendering and biodiesel manufacture processes. Monitoring is critical to addressing the knowledge gaps identified in 'Biodiesel from Specified Risk Material Tallow: An Appraisal of TSE Risks and their Reduction' (IEA's AMF Annex XXX, 2006) that prevent comprehensive risk assessment of TSE infectivity in products and waste. The most important challenge for monitoring TSE risk is the wide variety of sample types, which are generated at different points in the rendering/biodiesel production continuum. Conventional transmissible spongiform encephalopathy (TSE) assays were developed for specified risk material (SRM) and other biological tissues. These, however, are insufficient to address the diverse sample matrices produced in rendering and biodiesel manufacture. This paper examines the sample types expected in rendering and biodiesel manufacture and the implications of applying TSE assay methods to them. The authors then discuss a sample preparation filtration, which has not yet been applied to these sample types, but which has the potential to provide or significantly improve TSE monitoring. The main improvement will come from transfer of the prion proteins from the sample matrix to a matrix compatible with conventional and emerging bioassays. A second improvement will come from preconcentrating the prion proteins, which means transferring proteins from a larger sample volume into a smaller volume for analysis to provide greater detection sensitivity. This filtration method may also be useful for monitoring other samples, including wash waters and other waste streams, which may contain SRM, including those from abattoirs and on-farm operations. Finally, there is a discussion of emerging mass spectrometric methods, which Prusiner and others have shown to be suitable for detection and characterisation of prion proteins (Stahl

  18. LOD 1 VS. LOD 2 - Preliminary Investigations Into Differences in Mobile Rendering Performance

    Science.gov (United States)

    Ellul, C.; Altenbuchner, J.

    2013-09-01

    The increasing availability, size and detail of 3D City Model datasets has led to a challenge when rendering such data on mobile devices. Understanding the limitations to the usability of such models on these devices is particularly important given the broadening range of applications - such as pollution or noise modelling, tourism, planning, solar potential - for which these datasets and resulting visualisations can be utilized. Much 3D City Model data is created by extrusion of 2D topographic datasets, resulting in what is known as Level of Detail (LoD) 1 buildings - with flat roofs. However, in the UK the National Mapping Agency (the Ordnance Survey, OS) is now releasing test datasets to Level of Detail (LoD) 2 - i.e. including roof structures. These datasets are designed to integrate with the LoD 1 datasets provided by the OS, and provide additional detail in particular on larger buildings and in town centres. The availability of such integrated datasets at two different Levels of Detail permits investigation into the impact of the additional roof structures (and hence the display of a more realistic 3D City Model) on rendering performance on a mobile device. This paper describes preliminary work carried out to investigate this issue, for the test area of the city of Sheffield (in the UK Midlands). The data is stored in a 3D spatial database as triangles and then extracted and served as a web-based data stream which is queried by an App developed on the mobile device (using the Android environment, Java and OpenGL for graphics). Initial tests have been carried out on two dataset sizes, for the city centre and a larger area, rendering the data onto a tablet to compare results. Results of 52 seconds for rendering LoD 1 data, and 72 seconds for LoD 1 mixed with LoD 2 data, show that the impact of LoD 2 is significant.

  19. FluoRender: joint freehand segmentation and visualization for many-channel fluorescence data analysis.

    Science.gov (United States)

    Wan, Yong; Otsuna, Hideo; Holman, Holly A; Bagley, Brig; Ito, Masayoshi; Lewis, A Kelsey; Colasanto, Mary; Kardon, Gabrielle; Ito, Kei; Hansen, Charles

    2017-05-26

    Image segmentation and registration techniques have enabled biologists to place large amounts of volume data from fluorescence microscopy, morphed three-dimensionally, onto a common spatial frame. Existing tools built on volume visualization pipelines for single channel or red-green-blue (RGB) channels have become inadequate for the new challenges of fluorescence microscopy. For a three-dimensional atlas of the insect nervous system, hundreds of volume channels are rendered simultaneously, whereas fluorescence intensity values from each channel need to be preserved for versatile adjustment and analysis. Although several existing tools have incorporated support of multichannel data using various strategies, the lack of a flexible design has made true many-channel visualization and analysis unavailable. The most common practice for many-channel volume data presentation is still converting and rendering pseudosurfaces, which are inaccurate for both qualitative and quantitative evaluations. Here, we present an alternative design strategy that accommodates the visualization and analysis of about 100 volume channels, each of which can be interactively adjusted, selected, and segmented using freehand tools. Our multichannel visualization includes a multilevel streaming pipeline plus a triple-buffer compositing technique. Our method also preserves original fluorescence intensity values on graphics hardware, a crucial feature that allows graphics-processing-unit (GPU)-based processing for interactive data analysis, such as freehand segmentation. We have implemented the design strategies as a thorough restructuring of our original tool, FluoRender. The redesign of FluoRender not only maintains the existing multichannel capabilities for a greatly extended number of volume channels, but also enables new analysis functions for many-channel data from emerging biomedical-imaging techniques.

  20. An image-based approach to the rendering of crowds in real-time

    OpenAIRE

    Tecchia, Franco

    2007-01-01

    The wide use of computer graphics in games, entertainment, medical, architectural and cultural applications, has led it to becoming a prevalent area of research. Games and entertainment in general have become one of the driving forces of the real-time computer graphics industry, bringing reasonably realistic, complex and appealing virtual worlds to the mass-market. At the current stage of technology, an user can interactively navigate through complex, polygon-based scenes rendered with sophis...

  1. Efficient Algorithms for Real-Time GPU Volumetric Cloud Rendering with Enhanced Geometry

    OpenAIRE

    Carlos Jiménez de Parga; Sebastián Rubén Gómez Palomo

    2018-01-01

    This paper presents several new techniques for volumetric cloud rendering using efficient algorithms and data structures based on ray-tracing methods for cumulus generation, achieving an optimum balance between realism and performance. These techniques target applications such as flight simulations, computer games, and educational software, even with conventional graphics hardware. The contours of clouds are defined by implicit mathematical expressions or triangulated structures inside which ...

  2. Physiological role of growth factors and bone morphogenetic proteins in osteogenesis and bone fracture healing: а review

    Directory of Open Access Journals (Sweden)

    S. Sagalovsky

    2015-01-01

    Full Text Available The repair of large bone defects remains a major clinical orthopedic challenge. Bone regeneration and fracture healing is a complex physiological mechanisms regulated by a large number of biologically active molecules. Multiple factors regulate this cascade of molecular events, which affects different stages in the osteoblast and chondroblast lineage during such processes as migration, proliferation, chemotaxis, differentiation, inhibition, and extracellular protein synthesis. A recent review has focused on the mechanisms by which growth and differentiation factors regulate the fracture healing process. Rapid progress in skeletal cellular and molecular biology has led to identification of many signaling molecules associated with formation of skeletal tissues, including a large family of growth factors (transforming growth factor-β and bone morphogenetic proteins, fibroblast growth factor, insulin-like growth factor, vascular endothelial growth factor, platelet-derived growth factor, cytokines and interleukins. There is increasing evidence indicating that they are critical regulators of cellular proliferation, differentiation, extracellular matrix biosynthesis and bone mineralization. A clear understanding of cellular and molecular pathways involved in fracture healing is not only critical for improvement of fracture treatments, but it may also enhance further our knowledge of mechanisms involved in skeletal growth and repair, as well as mechanisms of aging. This suggests that, in the future, they may play a major role in the treatment of bone disease and fracture repair.

  3. Unconscious neural processing differs with method used to render stimuli invisible

    Directory of Open Access Journals (Sweden)

    Sergey Victor Fogelson

    2014-06-01

    Full Text Available Visual stimuli can be kept from awareness using various methods. The extent of processing that a given stimulus receives in the absence of awareness is typically used to make claims about the role of consciousness more generally. The neural processing elicited by a stimulus, however, may also depend on the method used to keep it from awareness, and not only on whether the stimulus reaches awareness. Here we report that the method used to render an image invisible has a dramatic effect on how category information about the unseen stimulus is encoded across the human brain. We collected fMRI data while subjects viewed images of faces and tools, that were rendered invisible using either continuous flash suppression (CFS or chromatic flicker fusion (CFF. In a third condition, we presented the same images under normal fully visible viewing conditions. We found that category information about visible images could be extracted from patterns of fMRI responses throughout areas of neocortex known to be involved in face or tool processing. However, category information about stimuli kept from awareness using CFS could be recovered exclusively within occipital cortex, whereas information about stimuli kept from awareness using CFF was also decodable within temporal and frontal regions. We conclude that unconsciously presented objects are processed differently depending on how they are rendered subjectively invisible. Caution should therefore be used in making generalizations on the basis of any one method about the neural basis of consciousness or the extent of information processing without consciousness.

  4. Unconscious neural processing differs with method used to render stimuli invisible.

    Science.gov (United States)

    Fogelson, Sergey V; Kohler, Peter J; Miller, Kevin J; Granger, Richard; Tse, Peter U

    2014-01-01

    Visual stimuli can be kept from awareness using various methods. The extent of processing that a given stimulus receives in the absence of awareness is typically used to make claims about the role of consciousness more generally. The neural processing elicited by a stimulus, however, may also depend on the method used to keep it from awareness, and not only on whether the stimulus reaches awareness. Here we report that the method used to render an image invisible has a dramatic effect on how category information about the unseen stimulus is encoded across the human brain. We collected fMRI data while subjects viewed images of faces and tools, that were rendered invisible using either continuous flash suppression (CFS) or chromatic flicker fusion (CFF). In a third condition, we presented the same images under normal fully visible viewing conditions. We found that category information about visible images could be extracted from patterns of fMRI responses throughout areas of neocortex known to be involved in face or tool processing. However, category information about stimuli kept from awareness using CFS could be recovered exclusively within occipital cortex, whereas information about stimuli kept from awareness using CFF was also decodable within temporal and frontal regions. We conclude that unconsciously presented objects are processed differently depending on how they are rendered subjectively invisible. Caution should therefore be used in making generalizations on the basis of any one method about the neural basis of consciousness or the extent of information processing without consciousness.

  5. CT portography by multidetector helical CT. Comparison of three rendering models

    International Nuclear Information System (INIS)

    Nakayama, Yoshiharu; Imuta, Masanori; Funama, Yoshinori; Kadota, Masataka; Utsunomiya, Daisuke; Shiraishi, Shinya; Hayashida, Yoshiko; Yamashita, Yasuyuki

    2002-01-01

    The purpose of this study was to assess the value of multidetector CT portography in visualizing varices and portosystemic collaterals in comparison with conventional portography, and to compare the visualizations obtained by three rendering models (volume rendering, VR; minimum intensity projection, MIP; and shaded surface display, SSD). A total of 46 patients with portal hypertension were examined by CT and conventional portography for evaluation of portosystemic collaterals. CT portography was performed by multidetector CT (MD-CT) scanner with a slice thickness of 2.5 mm and table feed of 7.5 mm. Three types of CT portographic models were generated and compared with transarterial portography. Among 46 patients, 48 collaterals were identified on CT transverse images, while 38 collaterals were detected on transarterial portography. Forty-four of 48 collaterals identified on CT transverse images were visualized with the MIP model, while 34 and 29 collaterals were visualized by the VR and SSD methods, respectively. The average CT value for the portal vein and varices was 198 HU with data acquisition of 50 sec after contrast material injection. CT portography by multidetector CT provides excellent images in the visualization of portosystemic collaterals. The images of collaterals produced by MD-CT are superior to those of transarterial portography. Among the three rendering techniques, MIP provides the best visualization of portosystemic collaterals. (author)

  6. One-Dimensional Haptic Rendering Using Audio Speaker with Displacement Determined by Inductance

    Directory of Open Access Journals (Sweden)

    Avin Khera

    2016-03-01

    Full Text Available We report overall design considerations and preliminary results for a new haptic rendering device based on an audio loudspeaker. Our application models tissue properties during microsurgery. For example, the device could respond to the tip of a tool by simulating a particular tissue, displaying a desired compressibility and viscosity, giving way as the tissue is disrupted, or exhibiting independent motion, such as that caused by pulsations in blood pressure. Although limited to one degree of freedom and with a relatively small range of displacement compared to other available haptic rendering devices, our design exhibits high bandwidth, low friction, low hysteresis, and low mass. These features are consistent with modeling interactions with delicate tissues during microsurgery. In addition, our haptic rendering device is designed to be simple and inexpensive to manufacture, in part through an innovative method of measuring displacement by existing variations in the speaker’s inductance as the voice coil moves over the permanent magnet. Low latency and jitter are achieved by running the real-time simulation models on a dedicated microprocessor, while maintaining bidirectional communication with a standard laptop computer for user controls and data logging.

  7. Forensic 3D Visualization of CT Data Using Cinematic Volume Rendering: A Preliminary Study.

    Science.gov (United States)

    Ebert, Lars C; Schweitzer, Wolf; Gascho, Dominic; Ruder, Thomas D; Flach, Patricia M; Thali, Michael J; Ampanozi, Garyfalia

    2017-02-01

    The 3D volume-rendering technique (VRT) is commonly used in forensic radiology. Its main function is to explain medical findings to state attorneys, judges, or police representatives. New visualization algorithms permit the generation of almost photorealistic volume renderings of CT datasets. The objective of this study is to present and compare a variety of radiologic findings to illustrate the differences between and the advantages and limitations of the current VRT and the physically based cinematic rendering technique (CRT). Seventy volunteers were shown VRT and CRT reconstructions of 10 different cases. They were asked to mark the findings on the images and rate them in terms of realism and understandability. A total of 48 of the 70 questionnaires were returned and included in the analysis. On the basis of most of the findings presented, CRT appears to be equal or superior to VRT with respect to the realism and understandability of the visualized findings. Overall, in terms of realism, the difference between the techniques was statistically significant (p 0.05). CRT, which is similar to conventional VRT, is not primarily intended for diagnostic radiologic image analysis, and therefore it should be used primarily as a tool to deliver visual information in the form of radiologic image reports. Using CRT for forensic visualization might have advantages over using VRT if conveying a high degree of visual realism is of importance. Most of the shortcomings of CRT have to do with the software being an early prototype.

  8. CT portography by multidetector helical CT. Comparison of three rendering models

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yoshiharu; Imuta, Masanori; Funama, Yoshinori; Kadota, Masataka; Utsunomiya, Daisuke; Shiraishi, Shinya; Hayashida, Yoshiko; Yamashita, Yasuyuki [Kumamoto Univ. (Japan). School of Medicine

    2002-12-01

    The purpose of this study was to assess the value of multidetector CT portography in visualizing varices and portosystemic collaterals in comparison with conventional portography, and to compare the visualizations obtained by three rendering models (volume rendering, VR; minimum intensity projection, MIP; and shaded surface display, SSD). A total of 46 patients with portal hypertension were examined by CT and conventional portography for evaluation of portosystemic collaterals. CT portography was performed by multidetector CT (MD-CT) scanner with a slice thickness of 2.5 mm and table feed of 7.5 mm. Three types of CT portographic models were generated and compared with transarterial portography. Among 46 patients, 48 collaterals were identified on CT transverse images, while 38 collaterals were detected on transarterial portography. Forty-four of 48 collaterals identified on CT transverse images were visualized with the MIP model, while 34 and 29 collaterals were visualized by the VR and SSD methods, respectively. The average CT value for the portal vein and varices was 198 HU with data acquisition of 50 sec after contrast material injection. CT portography by multidetector CT provides excellent images in the visualization of portosystemic collaterals. The images of collaterals produced by MD-CT are superior to those of transarterial portography. Among the three rendering techniques, MIP provides the best visualization of portosystemic collaterals. (author)

  9. Simulation and training of lumbar punctures using haptic volume rendering and a 6DOF haptic device

    Science.gov (United States)

    Färber, Matthias; Heller, Julika; Handels, Heinz

    2007-03-01

    The lumbar puncture is performed by inserting a needle into the spinal chord of the patient to inject medicaments or to extract liquor. The training of this procedure is usually done on the patient guided by experienced supervisors. A virtual reality lumbar puncture simulator has been developed in order to minimize the training costs and the patient's risk. We use a haptic device with six degrees of freedom (6DOF) to feedback forces that resist needle insertion and rotation. An improved haptic volume rendering approach is used to calculate the forces. This approach makes use of label data of relevant structures like skin, bone, muscles or fat and original CT data that contributes information about image structures that can not be segmented. A real-time 3D visualization with optional stereo view shows the punctured region. 2D visualizations of orthogonal slices enable a detailed impression of the anatomical context. The input data consisting of CT and label data and surface models of relevant structures is defined in an XML file together with haptic rendering and visualization parameters. In a first evaluation the visible human male data has been used to generate a virtual training body. Several users with different medical experience tested the lumbar puncture trainer. The simulator gives a good haptic and visual impression of the needle insertion and the haptic volume rendering technique enables the feeling of unsegmented structures. Especially, the restriction of transversal needle movement together with rotation constraints enabled by the 6DOF device facilitate a realistic puncture simulation.

  10. A Single Swede Midge (Diptera: Cecidomyiidae) Larva Can Render Cauliflower Unmarketable.

    Science.gov (United States)

    Stratton, Chase A; Hodgdon, Elisabeth A; Zuckerman, Samuel G; Shelton, Anthony M; Chen, Yolanda H

    2018-05-01

    Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is an invasive pest causing significant damage on Brassica crops in the Northeastern United States and Eastern Canada. Heading brassicas, like cauliflower, appear to be particularly susceptible. Swede midge is difficult to control because larvae feed concealed inside meristematic tissues of the plant. In order to develop damage and marketability thresholds necessary for integrated pest management, it is important to determine how many larvae render plants unmarketable and whether the timing of infestation affects the severity of damage. We manipulated larval density (0, 1, 3, 5, 10, or 20) per plant and the timing of infestation (30, 55, and 80 d after seeding) on cauliflower in the lab and field to answer the following questions: 1) What is the swede midge damage threshold? 2) How many swede midge larvae can render cauliflower crowns unmarketable? and 3) Does the age of cauliflower at infestation influence the severity of damage and marketability? We found that even a single larva can cause mild twisting and scarring in the crown rendering cauliflower unmarketable 52% of the time, with more larvae causing more severe damage and additional losses, regardless of cauliflower age at infestation.

  11. Adaptive B-spline volume representation of measured BRDF data for photorealistic rendering

    Directory of Open Access Journals (Sweden)

    Hyungjun Park

    2015-01-01

    Full Text Available Measured bidirectional reflectance distribution function (BRDF data have been used to represent complex interaction between lights and surface materials for photorealistic rendering. However, their massive size makes it hard to adopt them in practical rendering applications. In this paper, we propose an adaptive method for B-spline volume representation of measured BRDF data. It basically performs approximate B-spline volume lofting, which decomposes the problem into three sub-problems of multiple B-spline curve fitting along u-, v-, and w-parametric directions. Especially, it makes the efficient use of knots in the multiple B-spline curve fitting and thereby accomplishes adaptive knot placement along each parametric direction of a resulting B-spline volume. The proposed method is quite useful to realize efficient data reduction while smoothing out the noises and keeping the overall features of BRDF data well. By applying the B-spline volume models of real materials for rendering, we show that the B-spline volume models are effective in preserving the features of material appearance and are suitable for representing BRDF data.

  12. The lime renderings from plaza de la Corredera, Córdoba

    Directory of Open Access Journals (Sweden)

    González, T.

    2002-09-01

    Full Text Available The causes of the pathologies found on the lime renderings from Plaza de la Corredera façades are analysed in this study. For this purpose, the mineralogical and chemical analyses of the building materials -brickwork and rendering mortar- has been carried out, as well as their physical, hydric and mechanical properties have been determined. The obtained results from both unaltered and altered materials, and the analysis of the rendering's raw materials, have allowed us to establish that rendering deterioration is connected to the presence of saline compounds (gypsum, halite, which existing in the brickwork substratum, have been removed due to the water saturation of such brickwork. The main cause responsible of the alteration forms - efflorescence, crusts, grain-disintegration, bulging, flaking found on the renderings, has been the salts precipitation (halite, hexahydrite, epsomite in their way towards the external surface.

    En este estudio se analizan las causas de las patologías de los revocos de cal de las fachadas de la Plaza de la Corredera. Para ello se ha realizado el análisis mineralógico y químico de los materiales de construcción - fábrica de ladrillo y mortero de revestimiento- y se han determinado sus propiedades físicas, hídricas y mecánicas. Mediante la comparación de los resultados obtenidos en los materiales inalterados y en los alterados, así como una vez analizadas las materias primas utilizadas en la realización del revoco, se ha podido establecer que la alteración de este último está relacionada con la existencia de compuestos salinos (yeso, halita que, presentes en el substrato de fábrica de ladrillo, se han exudado por saturación de agua de la misma. La precipitación de las sales (halita, hexahidrita, epsomita en su migración hacia el exterior ha sido la principal responsable de las formas de alteración -eflorescencias, costras, arenización, abombamientos, descamaciones- que aparecen sobre los

  13. Visualization of normal and abnormal inner ear with volume rendering technique using multislice spiral CT

    International Nuclear Information System (INIS)

    Ma Hui; Han Ping; Liang Bo; Lei Ziqiao; Liu Fang; Tian Zhiliang

    2006-01-01

    Objective: To evaluate the ability of the volume rendering technique to display the normal and abnormal inner ear structures. Methods: Forty normal earand 61 abnormal inner ears (40 congenital inner ear malformations, 7 labyrinthitis ossificans, and 14 inner ear erosion caused by cholesteatomas) were examined with a MSCT scanner. Axial imaging were performed using the following parameters: 120 kV, 100 mAs, 0.75 mm slice thickness, a pitch factor of 1. The axial images of interested ears were reconstructed with 0.1 mm reconstruction increment and a FOV of 50 mm. The 3D reconstructions were done with volume rendering technique on the workstation. Results: In the subjects without ear disorders a high quality 3D visualization of the inner ear could be achieved. In the patients with inner ear' disorders all inner ear malformations could be clearly displayed on 3D images as follows: (1) Michel deformity (one ear): There was complete absence of all cochlear and vestibular structures. (2) common cavity deformity (3 ears): The cochlea and vestibule were represented by a cystic cavity and couldn't be differentiated from each other. (3)incomplete partition type I (3 ears): The cochlea lacked the entire modiolus and cribriform area, resulting in a cystic appearance. (4) incomplete partition type II (Mondini deformity) (5 ears): The cochlea consisted of 1.5 turns, in which the middle and apical turns coalesced to form a cystic apex. (5) vestibular and semicircular canal malformations (14 ears): Cochlea was normal, vestibule dilated, semicircular canals were absent, hypoplastic or enlarged. (6) dilated vestibular aqueduct (14 ears): The vestibular aqueduct was bell-mouthed. In 7 patients with labyrinthifis ossificans, 3D images failed to clearly show the completeinner ears in 4 ears because of too high ossifications in the membranous labyrinth. In the other 3 ears volume rendering could display the thin cochlea basal turn and the intermittent semicircular canals. In the patients

  14. Virtual reality system for treatment of the fear of public speaking using image-based rendering and moving pictures.

    Science.gov (United States)

    Lee, Jae M; Ku, Jeong H; Jang, Dong P; Kim, Dong H; Choi, Young H; Kim, In Y; Kim, Sun I

    2002-06-01

    The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology enabled us to use virtual reality (VR) for the treatment of the fear of public speaking. There have been two techniques used to construct a virtual environment for the treatment of the fear of public speaking: model-based and movie-based. Virtual audiences and virtual environments made by model-based technique are unrealistic and unnatural. The movie-based technique has a disadvantage in that each virtual audience cannot be controlled respectively, because all virtual audiences are included in one moving picture file. To address this disadvantage, this paper presents a virtual environment made by using image-based rendering (IBR) and chroma keying simultaneously. IBR enables us to make the virtual environment realistic because the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma keying allows a virtual audience to be controlled individually. In addition, a real-time capture technique was applied in constructing the virtual environment to give the subjects more interaction, in that they can talk with a therapist or another subject.

  15. Phosphoproteomic fingerprinting of epidermal growth factor signaling and anticancer drug action in human tumor cells.

    Science.gov (United States)

    Lim, Yoon-Pin; Diong, Lang-Shi; Qi, Robert; Druker, Brian J; Epstein, Richard J

    2003-12-01

    Many proteins regulating cancer cell growth are tyrosine phosphorylated. Using antiphosphotyrosine affinity chromatography, thiourea protein solubilization, two-dimensional PAGE, and mass spectrometry, we report here the characterization of the epidermal growth factor (EGF)-induced phosphoproteome in A431 human epidermoid carcinoma cells. Using this approach, more than 50 distinct tyrosine phosphoproteins are identifiable within five main clusters-cytoskeletal proteins, signaling enzymes, SH2-containing adaptors, chaperones, and focal adhesion proteins. Comparison of the phosphoproteomes induced in vitro by transforming growth factor-alpha and platelet-derived growth factor demonstrates the pathway- and cell-specific nature of the phosphoproteomes induced. Elimination of both basal and ligand-dependent phosphoproteins by cell exposure to the EGF receptor catalytic inhibitor gefitinib (Iressa, ZD1839) suggests either an autocrine growth loop or the presence of a second inhibited kinase in A431 cells. By identifying distinct patterns of phosphorylation involving novel signaling substrates, and by clarifying the mechanism of action of anticancer drugs, these findings illustrate the potential of immunoaffinity-based phosphoproteomics for guiding the discovery of new drug targets and the rational utilization of pathway-specific chemotherapies.

  16. Characterization of the growth of murine fibroblasts that express human insulin receptors. II. Interaction of insulin with other growth factors

    International Nuclear Information System (INIS)

    Randazzo, P.A.; Jarett, L.

    1990-01-01

    The effects of insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and insulin on DNA synthesis were studied in murine fibroblasts transfected with an expression vector containing human insulin receptor cDNA (NIH 3T3/HIR) and the parental NIH 3T3 cells. In NIH 3T3/HIR cells, individual growth factors in serum-free medium stimulated DNA synthesis with the following relative efficacies: insulin greater than or equal to 10% fetal calf serum greater than PDGF greater than IGF-1 much greater than EGF. In comparison, the relative efficacies of these factors in stimulating DNA synthesis by NIH 3T3 cells were 10% fetal calf serum greater than PDGF greater than EGF much greater than IGF-1 = insulin. In NIH 3T3/HIR cells, EGF was synergistic with 1-10 ng/ml insulin but not with 100 ng/ml insulin or more. Synergy of PDGF or IGF-1 with insulin was not detected. In the parental NIH 3T3 cells, insulin and IGF-1 were found to be synergistic with EGF (1 ng/ml), PDGF (100 ng/ml), and PDGF plus EGF. In NIH 3T3/HIR cells, the lack of interaction of insulin with other growth factors was also observed when the percentage of cells synthesizing DNA was examined. Despite insulin's inducing only 60% of NIH 3T3/HIR cells to incorporate thymidine, addition of PDGF, EGF, or PDGF plus EGF had no further effect. In contrast, combinations of growth factors resulted in 95% of the parental NIH 3T3 cells synthesizing DNA. The independence of insulin-stimulated DNA synthesis from other mitogens in the NIH 3T3/HIR cells is atypical for progression factor-stimulated DNA synthesis and is thought to be partly the result of insulin receptor expression in an inappropriate context or quantity

  17. VIDEO ANIMASI 3D PENGENALAN RUMAH ADAT DAN ALAT MUSIK KEPRI DENGAN MENGUNAKAN TEKNIK RENDER CEL-SHADING

    Directory of Open Access Journals (Sweden)

    Jianfranco Irfian Asnawi

    2016-11-01

    Full Text Available Animasi ini berjudul "video animasi 3D rumah adat dan alat musik Kepulauan Riau dengan menggunakan teknik render cel-shading" merupakan video yang bertujuan memperkenalkan alat-alat musik yang berasal dari kepulauan riau, Animasi ini akan diterapkan dengan menggunakan teknik render cel-shading. Cel-shading adalah teknik render yang menampilkan grafik 3D yang menyerupai gambar tangan, seperti gambar komik dan kartun. Teknik ini juga sudah di terapkan dalam game 3D yang ternyata menarik banyak perhatian peminat. Teknik ini akan di terapkan kedalam animasi 3D "video animasi rumah adat dan alat musik kepulauan riau dengan menggunakan teknik render cel-shading" Animasi di rancang menggunakan skenario dan storyboard kemudian di implementasikan dalam software 3D MAYA AUTODESK dengan menggunakan teknik render cel-shading. Setelah diterapkan maka di dapatkan definisi keberhasilan dari teknik render cel shading di bandingkan dengan teknik render global illumination seperti dari kecepatan dalam merender dan tingkat kecerahan warna pada video. Kata kunci: animasi, game 3D, cel-shading.

  18. Advantages and disadvantages of 3D ultrasound of thyroid nodules including thin slice volume rendering

    Directory of Open Access Journals (Sweden)

    Slapa Rafal

    2011-01-01

    Full Text Available Abstract Background The purpose of this study was to assess the advantages and disadvantages of 3D gray-scale and power Doppler ultrasound, including thin slice volume rendering (TSVR, applied for evaluation of thyroid nodules. Methods The retrospective evaluation by two observers of volumes of 71 thyroid nodules (55 benign, 16 cancers was performed using a new TSVR technique. Dedicated 4D ultrasound scanner with an automatic 6-12 MHz 4D probe was used. Statistical analysis was performed with Stata v. 8.2. Results Multiple logistic regression analysis demonstrated that independent risk factors of thyroid cancers identified by 3D ultrasound include: (a ill-defined borders of the nodule on MPR presentation, (b a lobulated shape of the nodule in the c-plane and (c a density of central vessels in the nodule within the minimal or maximal ranges. Combination of features provided sensitivity 100% and specificity 60-69% for thyroid cancer. Calcification/microcalcification-like echogenic foci on 3D ultrasound proved not to be a risk factor of thyroid cancer. Storage of the 3D data of the whole nodules enabled subsequent evaluation of new parameters and with new rendering algorithms. Conclusions Our results indicate that 3D ultrasound is a practical and reproducible method for the evaluation of thyroid nodules. 3D ultrasound stores volumes comprising the whole lesion or organ. Future detailed evaluations of the data are possible, looking for features that were not fully appreciated at the time of collection or applying new algorithms for volume rendering in order to gain important information. Three-dimensional ultrasound data could be included in thyroid cancer databases. Further multicenter large scale studies are warranted.

  19. A Case Study of a Hybrid Parallel 3D Surface Rendering Graphics Architecture

    DEFF Research Database (Denmark)

    Holten-Lund, Hans Erik; Madsen, Jan; Pedersen, Steen

    1997-01-01

    This paper presents a case study in the design strategy used inbuilding a graphics computer, for drawing very complex 3Dgeometric surfaces. The goal is to build a PC based computer systemcapable of handling surfaces built from about 2 million triangles, andto be able to render a perspective view...... of these on a computer displayat interactive frame rates, i.e. processing around 50 milliontriangles per second. The paper presents a hardware/softwarearchitecture called HPGA (Hybrid Parallel Graphics Architecture) whichis likely to be able to carry out this task. The case study focuses ontechniques to increase...

  20. [Rendering surgical care to wounded with neck wounds in an armed conflict].

    Science.gov (United States)

    Samokhvalov, I M; Zavrazhnov, A A; Fakhrutdinov, A M; Sychev, M I

    2001-10-01

    The results of rendering of the medical care (the first aid, qualified and specialized) obtained in 172 servicemen with neck injuries who stayed in Republic of Chechnya during the period from 09.08.1999 to 28.07.2000 were analyzed. Basing on the results of analysis and experience of casualties' treatment the authors discuss the problems of sequence and volume of surgical care in this group of casualties with reference to available medical evacuation system, surgical tactics at the stage of specialized care. They also consider the peculiarities of operative treatment of the casualties with neck injuries.

  1. Experimental and rendering-based investigation of laser radar cross sections of small unmanned aerial vehicles

    Science.gov (United States)

    Laurenzis, Martin; Bacher, Emmanuel; Christnacher, Frank

    2017-12-01

    Laser imaging systems are prominent candidates for detection and tracking of small unmanned aerial vehicles (UAVs) in current and future security scenarios. Laser reflection characteristics for laser imaging (e.g., laser gated viewing) of small UAVs are investigated to determine their laser radar cross section (LRCS) by analyzing the intensity distribution of laser reflection in high resolution images. For the first time, LRCSs are determined in a combined experimental and computational approaches by high resolution laser gated viewing and three-dimensional rendering. An optimized simple surface model is calculated taking into account diffuse and specular reflectance properties based on the Oren-Nayar and the Cook-Torrance reflectance models, respectively.

  2. Peeling tests for assessing the cohesion and consolidation characteristics of mortar and render surfaces

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš; Lesák, Jaroslav; Niedoba, Krzysztof; Valach, Jaroslav

    2015-01-01

    Roč. 48, č. 6 (2015), s. 1947-1963 ISSN 1359-5997 R&D Projects: GA ČR(CZ) GBP105/12/G059; GA MŠk(CZ) ED1.1.00/02.0060 Institutional support: RVO:68378297 Keywords : peeling test * rendered surface * surface consolidation * cohesion * non-destructive testing Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 2.453, year: 2015 http://link.springer.com/article/10.1617/s11527-014-0285-8

  3. Semiconductive 3-D haloplumbate framework hybrids with high color rendering index white-light emission.

    Science.gov (United States)

    Wang, Guan-E; Xu, Gang; Wang, Ming-Sheng; Cai, Li-Zhen; Li, Wen-Hua; Guo, Guo-Cong

    2015-12-01

    Single-component white light materials may create great opportunities for novel conventional lighting applications and display systems; however, their reported color rendering index (CRI) values, one of the key parameters for lighting, are less than 90, which does not satisfy the demand of color-critical upmarket applications, such as photography, cinematography, and art galleries. In this work, two semiconductive chloroplumbate (chloride anion of lead(ii)) hybrids, obtained using a new inorganic-organic hybrid strategy, show unprecedented 3-D inorganic framework structures and white-light-emitting properties with high CRI values around 90, one of which shows the highest value to date.

  4. Use of multidetector row CT with volume renderings in right lobe living liver transplantation

    International Nuclear Information System (INIS)

    Ishifuro, Minoru; Akiyama, Yuji; Kushima, Toshio; Horiguchi, Jun; Nakashige, Aya; Tamura, Akihisa; Marukawa, Kazushi; Fukuda, Hiroshi; Ono, Chiaki; Ito, Katsuhide

    2002-01-01

    Multidetector row CT is a feasible diagnostic tool in pre- and postoperative liver partial transplantation. We can assess vascular anatomy and liver parenchyma as well as volumetry, which provide useful information for both donor selection and surgical planning. Disorders of the vascular and biliary systems are carefully observed in recipients. In addition, we evaluate liver regeneration of both the donor and the recipient by serial volumetry. We present how multidetector row CT with state-of-the-art three-dimensional volume renderings may be used in right lobe liver transplantation. (orig.)

  5. Uniform illumination rendering using an array of LEDs: a signal processing perspective

    OpenAIRE

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.; Linnartz, J.P.M.G.; Rietman, R.

    2009-01-01

    An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic illumination pattern, i.e., the light pattern of a single LED, and the setting of LED illumination levels, respectively. Thereafter, we propose to use the relative mean squared error as the cost function ...

  6. Predicting the long-term durability of hemp-lime renders in inland and coastal areas using Mediterranean, Tropical and Semi-arid climatic simulations.

    Science.gov (United States)

    Arizzi, Anna; Viles, Heather; Martín-Sanchez, Inés; Cultrone, Giuseppe

    2016-01-15

    Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp-lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp-lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp-lime mixes. This study has demonstrated that hemp-lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Meningioma growth and interferon beta-1b treated multiple sclerosis: coincidence or relationship?

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, A.; Xinou, E. [AHEPA University Hospital, Aristotele University School of Medicine, Department of Radiology, Thessaloniki (Greece); Karacostas, D.; Parissis, D.; Milonas, I. [AHEPA University Hospital, Aristotele University School of Medicine, B' Department of Neurology, Thessaloniki (Greece); Karkavelas, G. [AHEPA University Hospital, Aristotele University School of Medicine, Laboratory of Pathology, Thessaloniki (Greece)

    2005-07-01

    Although the coincidence of multiple sclerosis (MS) and central nervous system (CNS) tumors has been reported in over 30 cases in English literature, meningioma growth was associated with interferon-beta (INF-b) treated MS only in two of them. We report the case of a 19-year-old woman with clinically possible, laboratory supported MS, and a concomitant right intraventricular tumor with magnetic resonance imaging (MRI) characteristics consistent with meningioma (similar signal with grey matter on T1 and T2-weighted images and homogenous, intense enhancement). Two years after initiation of INF-b treatment, follow-up brain MRI revealed enlargement of the intraventricular mass and relative increase in the number of white matter lesions without significant clinical deterioration. She underwent almost total resection of the mass and histology confirmed the diagnosis of papillary meningioma. Based on the immunohistochemistry results, we speculate that INF-b resulted in meningioma growth by enhancing platelet derived growth factor (PDGF) receptors or/and down-regulating transforming growth factor receptors on the tumor itself. (orig.)

  8. Meningioma growth and interferon beta-1b treated multiple sclerosis: coincidence or relationship?

    International Nuclear Information System (INIS)

    Drevelegas, A.; Xinou, E.; Karacostas, D.; Parissis, D.; Milonas, I.; Karkavelas, G.

    2005-01-01

    Although the coincidence of multiple sclerosis (MS) and central nervous system (CNS) tumors has been reported in over 30 cases in English literature, meningioma growth was associated with interferon-beta (INF-b) treated MS only in two of them. We report the case of a 19-year-old woman with clinically possible, laboratory supported MS, and a concomitant right intraventricular tumor with magnetic resonance imaging (MRI) characteristics consistent with meningioma (similar signal with grey matter on T1 and T2-weighted images and homogenous, intense enhancement). Two years after initiation of INF-b treatment, follow-up brain MRI revealed enlargement of the intraventricular mass and relative increase in the number of white matter lesions without significant clinical deterioration. She underwent almost total resection of the mass and histology confirmed the diagnosis of papillary meningioma. Based on the immunohistochemistry results, we speculate that INF-b resulted in meningioma growth by enhancing platelet derived growth factor (PDGF) receptors or/and down-regulating transforming growth factor receptors on the tumor itself. (orig.)

  9. Development of volume rendering module for real-time visualization system

    International Nuclear Information System (INIS)

    Otani, Takayuki; Muramatsu, Kazuhiro

    2000-03-01

    Volume rendering is a method to visualize the distribution of physical quantities in the three dimensional space from any viewpoint by tracing the ray direction on the ordinary two dimensional monitoring display. It enables to provide the interior information as well as the surfacial one by producing the translucent images. Therefore, it is regarded as a very useful means as well as an important one in the analysis of the computational results of the scientific calculations, although it has, unfortunately, disadvantage to need a large amount of computing time. This report describes algorithm and its performance of the volume rendering soft-ware which was developed as an important functional module in the real-time visualization system PATRAS. This module can directly visualize the computed results on BFC grid. Moreover, it has already realized the speed-up in some parts of the software by the use of a newly developed heuristic technique. This report includes the investigation on the speed-up of the software by parallel processing. (author)

  10. State of the Art in Transfer Functions for Direct Volume Rendering

    KAUST Repository

    Ljung, Patric; Krü ger, Jens; Groller, Eduard; Hadwiger, Markus; Hansen, Charles D.; Ynnerman, Anders

    2016-01-01

    A central topic in scientific visualization is the transfer function (TF) for volume rendering. The TF serves a fundamental role in translating scalar and multivariate data into color and opacity to express and reveal the relevant features present in the data studied. Beyond this core functionality, TFs also serve as a tool for encoding and utilizing domain knowledge and as an expression for visual design of material appearances. TFs also enable interactive volumetric exploration of complex data. The purpose of this state-of-the-art report (STAR) is to provide an overview of research into the various aspects of TFs, which lead to interpretation of the underlying data through the use of meaningful visual representations. The STAR classifies TF research into the following aspects: dimensionality, derived attributes, aggregated attributes, rendering aspects, automation, and user interfaces. The STAR concludes with some interesting research challenges that form the basis of an agenda for the development of next generation TF tools and methodologies. © 2016 The Author(s) Computer Graphics Forum © 2016 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  11. Evaluating Approaches to Rendering Braille Text on a High-Density Pin Display.

    Science.gov (United States)

    Morash, Valerie S; Russomanno, Alexander; Gillespie, R Brent; OModhrain, Sile

    2017-10-13

    Refreshable displays for tactile graphics are typically composed of pins that have smaller diameters and spacing than standard braille dots. We investigated configurations of high-density pins to form braille text on such displays using non-refreshable stimuli produced with a 3D printer. Normal dot braille (diameter 1.5 mm) was compared to high-density dot braille (diameter 0.75 mm) wherein each normal dot was rendered by high-density simulated pins alone or in a cluster of pins configured in a diamond, X, or square; and to "blobs" that could result from covering normal braille and high-density multi-pin configurations with a thin membrane. Twelve blind participants read MNREAD sentences displayed in these conditions. For high-density simulated pins, single pins were as quickly and easily read as normal braille, but diamond, X, and square multi-pin configurations were slower and/or harder to read than normal braille. We therefore conclude that as long as center-to-center dot spacing and dot placement is maintained, the dot diameter may be open to variability for rendering braille on a high density tactile display.

  12. Mesophilic and thermophilic anaerobic co-digestion of rendering plant and slaughterhouse wastes.

    Science.gov (United States)

    Bayr, Suvi; Rantanen, Marianne; Kaparaju, Prasad; Rintala, Jukka

    2012-01-01

    Co-digestion of rendering and slaughterhouse wastes was studied in laboratory scale semi-continuously fed continuously stirred tank reactors (CSTRs) at 35 and 55 °C. All in all, 10 different rendering plant and slaughterhouse waste fractions were characterised showing high contents of lipids and proteins, and methane potentials of 262-572 dm(3)CH(4)/kg volatile solids(VS)(added). In mesophilic CSTR methane yields of ca 720 dm(3) CH(4)/kg VS(fed) were obtained with organic loading rates (OLR) of 1.0 and 1.5 kg VS/m(3) d, and hydraulic retention time (HRT) of 50 d. For thermophilic process, the lowest studied OLR of 1.5 kg VS/m(3) d, turned to be unstable after operation of 1.5 HRT, due to accumulating ammonia, volatile fatty acids (VFAs) and probably also long chain fatty acids (LCFAs). In conclusion, mesophilic process was found to be more feasible for co-digestion than thermophilic process, methane yields being higher and process more stable in mesophilic conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Clinical application of three-dimensional spiral CT cerebral angiography with volume rendering

    International Nuclear Information System (INIS)

    Duan Shaoyin; Huang Xi'en; Kang Jianghe; Zhang Dantong; Lin Qingchi; Cai Guoxiang; Xu Meixin; Pang Ruilin

    2002-01-01

    Objective: To study the methodology and assess the clinical value of three-dimensional CT angiography (3D-CTA) with volume rendering (VR) in cerebral vessels. Methods: Sixty-two patients were examined by means of 3D-CTA with volume rendering. VR was used in the reconstruction of 3D images, and the demonstration of normal vessels and vascular lesions were particularly analyzed. At the same time, comparisons were made between the images of VR and SSD, MIP, and also between the diagnosis of VR-CTA and DSA or postoperative results. Results: In VR images, cerebral vessel routes and vessel cavities were showed clearly, while the relationship among vascular lesions, surrounding vessels, and neighboring structure was distinguished. 50 cases (80.6%) were found positive, 48 of which were correct and 2 were false-positive compared with DSA or postoperative results. The accurate rate of diagnosis was 96.0%. There was no obvious difference in showing the cerebral vessel among the images of VR, SSD and MIP (P > 0.25). Conclusion: Three-dimensional CT cerebral angiography with VR is a new noninvasive effective method. It can even partly replace the DSA. The 3D-images have the characteristics of showing the cerebral vascular cavity and overlapped vessels without cutting the skull

  14. INCREASING SAVING BEHAVIOR THROUGH AGE-PROGRESSED RENDERINGS OF THE FUTURE SELF

    Science.gov (United States)

    HERSHFIELD, HAL E.; GOLDSTEIN, DANIEL G.; SHARPE, WILLIAM F.; FOX, JESSE; YEYKELIS, LEO; CARSTENSEN, LAURA L.; BAILENSON, JEREMY N.

    2014-01-01

    Many people fail to save what they need to for retirement (Munnell, Webb, and Golub-Sass 2009). Research on excessive discounting of the future suggests that removing the lure of immediate rewards by pre-committing to decisions, or elaborating the value of future rewards can both make decisions more future-oriented. In this article, we explore a third and complementary route, one that deals not with present and future rewards, but with present and future selves. In line with thinkers who have suggested that people may fail, through a lack of belief or imagination, to identify with their future selves (Parfit 1971; Schelling 1984), we propose that allowing people to interact with age-progressed renderings of themselves will cause them to allocate more resources toward the future. In four studies, participants interacted with realistic computer renderings of their future selves using immersive virtual reality hardware and interactive decision aids. In all cases, those who interacted with virtual future selves exhibited an increased tendency to accept later monetary rewards over immediate ones. PMID:24634544

  15. 3D-TV System with Depth-Image-Based Rendering Architectures, Techniques and Challenges

    CERN Document Server

    Zhao, Yin; Yu, Lu; Tanimoto, Masayuki

    2013-01-01

    Riding on the success of 3D cinema blockbusters and advances in stereoscopic display technology, 3D video applications have gathered momentum in recent years. 3D-TV System with Depth-Image-Based Rendering: Architectures, Techniques and Challenges surveys depth-image-based 3D-TV systems, which are expected to be put into applications in the near future. Depth-image-based rendering (DIBR) significantly enhances the 3D visual experience compared to stereoscopic systems currently in use. DIBR techniques make it possible to generate additional viewpoints using 3D warping techniques to adjust the perceived depth of stereoscopic videos and provide for auto-stereoscopic displays that do not require glasses for viewing the 3D image.   The material includes a technical review and literature survey of components and complete systems, solutions for technical issues, and implementation of prototypes. The book is organized into four sections: System Overview, Content Generation, Data Compression and Transmission, and 3D V...

  16. INCREASING SAVING BEHAVIOR THROUGH AGE-PROGRESSED RENDERINGS OF THE FUTURE SELF.

    Science.gov (United States)

    Hershfield, Hal E; Goldstein, Daniel G; Sharpe, William F; Fox, Jesse; Yeykelis, Leo; Carstensen, Laura L; Bailenson, Jeremy N

    2011-11-01

    Many people fail to save what they need to for retirement (Munnell, Webb, and Golub-Sass 2009). Research on excessive discounting of the future suggests that removing the lure of immediate rewards by pre-committing to decisions, or elaborating the value of future rewards can both make decisions more future-oriented. In this article, we explore a third and complementary route, one that deals not with present and future rewards, but with present and future selves. In line with thinkers who have suggested that people may fail, through a lack of belief or imagination, to identify with their future selves (Parfit 1971; Schelling 1984), we propose that allowing people to interact with age-progressed renderings of themselves will cause them to allocate more resources toward the future. In four studies, participants interacted with realistic computer renderings of their future selves using immersive virtual reality hardware and interactive decision aids. In all cases, those who interacted with virtual future selves exhibited an increased tendency to accept later monetary rewards over immediate ones.

  17. Virtual endoscopy and 3D volume rendering in the management of frontal sinus fractures.

    Science.gov (United States)

    Belina, Stanko; Cuk, Viseslav; Klapan, Ivica

    2009-12-01

    Frontal sinus fractures (FSF) are commonly caused by traffic accidents, assaults, industrial accidents and gunshot wounds. Classical roentgenography has high proportion of false negative findings in cases of FSF and is not particularly useful in examining the severity of damage to the frontal sinus posterior table and the nasofrontal duct region. High resolution computed tomography was inavoidable during the management of such patients but it may produce large quantity of 2D images. Postprocessing of datasets acquired by high resolution computer tomography from patients with severe head trauma may offer a valuable additional help in diagnostics and surgery planning. We performed virtual endoscopy (VE) and 3D volume rendering (3DVR) on high resolution CT data acquired from a 54-year-old man with with both anterior and posterior frontal sinus wall fracture in order to demonstrate advantages and disadvantages of these methods. Data acquisition was done by Siemens Somatom Emotion scanner and postprocessing was performed with Syngo 2006G software. VE and 3DVR were performed in a man who suffered blunt trauma to his forehead and nose in an traffic accident. Left frontal sinus anterior wall fracture without dislocation and fracture of tabula interna with dislocation were found. 3D position and orientation of fracture lines were shown in by 3D rendering software. We concluded that VE and 3DVR can clearly display the anatomic structure of the paranasal sinuses and nasopharyngeal cavity, revealing damage to the sinus wall caused by a fracture and its relationship to surrounding anatomical structures.

  18. Radionuclide cisternography: SPECT and 3D-rendering. Radionuklidzisternographie: SPECT- und 3D-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Henkes, H; Huber, G; Piepgras, U [Universitaet des Saarlandes, Homburg/Saar (Germany, F.R.). Abt. fuer Neuroradiologie; Hierholzer, J [Freie Univ. Berlin (Germany, F.R.). Strahlenklinik und Poliklinik; Cordes, M [British Columbia Univ., Vancouver, BC (Canada). Belzberg Lab. of Neuroscience

    1991-10-01

    Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of {sup 111}In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns. (orig.).

  19. Ethylene signaling renders the jasmonate response of Arabidopsis insensitive to future suppression by salicylic Acid.

    Science.gov (United States)

    Leon-Reyes, Antonio; Du, Yujuan; Koornneef, Annemart; Proietti, Silvia; Körbes, Ana P; Memelink, Johan; Pieterse, Corné M J; Ritsema, Tita

    2010-02-01

    Cross-talk between jasmonate (JA), ethylene (ET), and Salicylic acid (SA) signaling is thought to operate as a mechanism to fine-tune induced defenses that are activated in response to multiple attackers. Here, 43 Arabidopsis genotypes impaired in hormone signaling or defense-related processes were screened for their ability to express SA-mediated suppression of JA-responsive gene expression. Mutant cev1, which displays constitutive expression of JA and ET responses, appeared to be insensitive to SA-mediated suppression of the JA-responsive marker genes PDF1.2 and VSP2. Accordingly, strong activation of JA and ET responses by the necrotrophic pathogens Botrytis cinerea and Alternaria brassicicola prior to SA treatment counteracted the ability of SA to suppress the JA response. Pharmacological assays, mutant analysis, and studies with the ET-signaling inhibitor 1-methylcyclopropene revealed that ET signaling renders the JA response insensitive to subsequent suppression by SA. The APETALA2/ETHYLENE RESPONSE FACTOR transcription factor ORA59, which regulates JA/ET-responsive genes such as PDF1.2, emerged as a potential mediator in this process. Collectively, our results point to a model in which simultaneous induction of the JA and ET pathway renders the plant insensitive to future SA-mediated suppression of JA-dependent defenses, which may prioritize the JA/ET pathway over the SA pathway during multi-attacker interactions.

  20. Signal Processing Implementation and Comparison of Automotive Spatial Sound Rendering Strategies

    Directory of Open Access Journals (Sweden)

    Bai MingsianR

    2009-01-01

    Full Text Available Design and implementation strategies of spatial sound rendering are investigated in this paper for automotive scenarios. Six design methods are implemented for various rendering modes with different number of passengers. Specifically, the downmixing algorithms aimed at balancing the front and back reproductions are developed for the 5.1-channel input. Other five algorithms based on inverse filtering are implemented in two approaches. The first approach utilizes binaural (Head-Related Transfer Functions HRTFs measured in the car interior, whereas the second approach named the point-receiver model targets a point receiver positioned at the center of the passenger's head. The proposed processing algorithms were compared via objective and subjective experiments under various listening conditions. Test data were processed by the multivariate analysis of variance (MANOVA method and the least significant difference (Fisher's LSD method as a post hoc test to justify the statistical significance of the experimental data. The results indicate that inverse filtering algorithms are preferred for the single passenger mode. For the multipassenger mode, however, downmixing algorithms generally outperformed the other processing techniques.

  1. Complex adaptation-based LDR image rendering for 3D image reconstruction

    Science.gov (United States)

    Lee, Sung-Hak; Kwon, Hyuk-Ju; Sohng, Kyu-Ik

    2014-07-01

    A low-dynamic tone-compression technique is developed for realistic image rendering that can make three-dimensional (3D) images similar to realistic scenes by overcoming brightness dimming in the 3D display mode. The 3D surround provides varying conditions for image quality, illuminant adaptation, contrast, gamma, color, sharpness, and so on. In general, gain/offset adjustment, gamma compensation, and histogram equalization have performed well in contrast compression; however, as a result of signal saturation and clipping effects, image details are removed and information is lost on bright and dark areas. Thus, an enhanced image mapping technique is proposed based on space-varying image compression. The performance of contrast compression is enhanced with complex adaptation in a 3D viewing surround combining global and local adaptation. Evaluating local image rendering in view of tone and color expression, noise reduction, and edge compensation confirms that the proposed 3D image-mapping model can compensate for the loss of image quality in the 3D mode.

  2. In Vivo CT Direct Volume Rendering: A Three-Dimensional Anatomical Description of the Heart

    International Nuclear Information System (INIS)

    Cutroneo, Giuseppina; Bruschetta, Daniele; Trimarchi, Fabio; Cacciola, Alberto; Cinquegrani, Maria; Duca, Antonio; Rizzo, Giuseppina; Alati, Emanuela; Gaeta, Michele; Milardi, Demetrio

    2016-01-01

    Since cardiac anatomy continues to play an important role in the practice of medicine and in the development of medical devices, the study of the heart in three dimensions is particularly useful to understand its real structure, function and proper location in the body. This study demonstrates a fine use of direct volume rendering, processing the data set images obtained by Computed Tomography (CT) of the heart of 5 subjects with age range between 18 and 42 years (2 male, 3 female), with no history of any overt cardiac disease. The cardiac structure in CT images was first extracted from the thorax by marking manually the regions of interest on the computer, and then it was stacked to create new volumetric data. The use of a specific algorithm allowed us to observe with a good perception of depth the heart and the skeleton of the thorax at the same time. Besides, in all examined subjects, it was possible to depict its structure and its position within the body and to study the integrity of papillary muscles, the fibrous tissue of cardiac valve and chordae tendineae and the course of coronary arteries. Our results demonstrated that one of the greatest advantages of algorithmic modifications of direct volume rendering parameters is that this method provides much necessary information in a single radiologic study. It implies a better accuracy in the study of the heart, being complementary to other diagnostic methods and facilitating the therapeutic plans

  3. Efficient Algorithms for Real-Time GPU Volumetric Cloud Rendering with Enhanced Geometry

    Directory of Open Access Journals (Sweden)

    Carlos Jiménez de Parga

    2018-04-01

    Full Text Available This paper presents several new techniques for volumetric cloud rendering using efficient algorithms and data structures based on ray-tracing methods for cumulus generation, achieving an optimum balance between realism and performance. These techniques target applications such as flight simulations, computer games, and educational software, even with conventional graphics hardware. The contours of clouds are defined by implicit mathematical expressions or triangulated structures inside which volumetric rendering is performed. Novel techniques are used to reproduce the asymmetrical nature of clouds and the effects of light-scattering, with low computing costs. The work includes a new method to create randomized fractal clouds using a recursive grammar. The graphical results are comparable to those produced by state-of-the-art, hyper-realistic algorithms. These methods provide real-time performance, and are superior to particle-based systems. These outcomes suggest that our methods offer a good balance between realism and performance, and are suitable for use in the standard graphics industry.

  4. 3D cinematic rendering of the calvarium, maxillofacial structures, and skull base: preliminary observations.

    Science.gov (United States)

    Rowe, Steven P; Zinreich, S James; Fishman, Elliot K

    2018-06-01

    Three-dimensional (3D) visualizations of volumetric data from CT have gained widespread clinical acceptance and are an important method for evaluating complex anatomy and pathology. Recently, cinematic rendering (CR), a new 3D visualization methodology, has become available. CR utilizes a lighting model that allows for the production of photorealistic images from isotropic voxel data. Given how new this technique is, studies to evaluate its clinical utility and any potential advantages or disadvantages relative to other 3D methods such as volume rendering have yet to be published. In this pictorial review, we provide examples of normal calvarial, maxillofacial, and skull base anatomy and pathological conditions that highlight the potential for CR images to aid in patient evaluation and treatment planning. The highly detailed images and nuanced shadowing that are intrinsic to CR are well suited to the display of the complex anatomy in this region of the body. We look forward to studies with CR that will ascertain the ultimate value of this methodology to evaluate calvarium, maxillofacial, and skull base morphology as well as other complex anatomic structures.

  5. State of the Art in Transfer Functions for Direct Volume Rendering

    KAUST Repository

    Ljung, Patric

    2016-07-04

    A central topic in scientific visualization is the transfer function (TF) for volume rendering. The TF serves a fundamental role in translating scalar and multivariate data into color and opacity to express and reveal the relevant features present in the data studied. Beyond this core functionality, TFs also serve as a tool for encoding and utilizing domain knowledge and as an expression for visual design of material appearances. TFs also enable interactive volumetric exploration of complex data. The purpose of this state-of-the-art report (STAR) is to provide an overview of research into the various aspects of TFs, which lead to interpretation of the underlying data through the use of meaningful visual representations. The STAR classifies TF research into the following aspects: dimensionality, derived attributes, aggregated attributes, rendering aspects, automation, and user interfaces. The STAR concludes with some interesting research challenges that form the basis of an agenda for the development of next generation TF tools and methodologies. © 2016 The Author(s) Computer Graphics Forum © 2016 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  6. Pulmonary nodules: sensitivity of maximum intensity projection versus that of volume rendering of 3D multidetector CT data

    NARCIS (Netherlands)

    Peloschek, Philipp; Sailer, Johannes; Weber, Michael; Herold, Christian J.; Prokop, Mathias; Schaefer-Prokop, Cornelia

    2007-01-01

    PURPOSE: To prospectively compare maximum intensity projection (MIP) and volume rendering (VR) of multidetector computed tomographic (CT) data for the detection of small intrapulmonary nodules. MATERIALS AND METHODS: This institutional review board-approved prospective study included 20 oncology

  7. Predicting the long-term durability of hemp–lime renders in inland and coastal areas using Mediterranean, Tropical and Semi-arid climatic simulations

    International Nuclear Information System (INIS)

    Arizzi, Anna; Viles, Heather; Martín-Sanchez, Inés; Cultrone, Giuseppe

    2016-01-01

    Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp–lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp–lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp–lime mixes. This study has demonstrated that hemp–lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site. - Highlights: • Realistic simulations in the cabinet of one-year exposure to environmental conditions • Influence of the lime type on the durability of hemp–lime renders

  8. Predicting the long-term durability of hemp–lime renders in inland and coastal areas using Mediterranean, Tropical and Semi-arid climatic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Arizzi, Anna, E-mail: anna.arizzi@ouce.ox.ac.uk [School of Geography and the Environment, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY (United Kingdom); Viles, Heather [School of Geography and the Environment, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY (United Kingdom); Martín-Sanchez, Inés [Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18002 Granada (Spain); Cultrone, Giuseppe [Departamento de Mineralogía y Petrología, Universidad de Granada, Avda. Fuentenueva s/n, 18002 Granada (Spain)

    2016-01-15

    Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp–lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp–lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp–lime mixes. This study has demonstrated that hemp–lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site. - Highlights: • Realistic simulations in the cabinet of one-year exposure to environmental conditions • Influence of the lime type on the durability of hemp–lime renders

  9. Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp

    International Nuclear Information System (INIS)

    Bayr, S.; Ojanperä, M.; Kaparaju, P.; Rintala, J.

    2014-01-01

    Highlights: • Rendering wastes’ mono-digestion and co-digestion with potato pulp were studied. • CSTR process with OLR of 1.5 kg VS/m 3 d, HRT of 50 d was unstable in mono-digestion. • Free NH 3 inhibited mono-digestion of rendering wastes. • CSTR process with OLR of 1.5 kg VS/m 3 d, HRT of 50 d was stable in co-digestion. • Co-digestion increased methane yield somewhat compared to mono-digestion. - Abstract: In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55 °C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH 4 -N and/or free NH 3 ) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m 3 d and hydraulic retention time (HRT) of 50 d was unstable and resulted in methane yields of 450 dm 3 /kg VS fed . On the other hand, co-digestion of rendering wastes with potato pulp (60% wet weight, WW) at the same OLR and HRT improved the process stability and increased methane yields (500–680 dm 3 /kg VS fed ). Thus, it can be concluded that co-digestion of rendering wastes with potato pulp could improve the process stability and methane yields from these difficult to treat industrial waste materials

  10. Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp

    Energy Technology Data Exchange (ETDEWEB)

    Bayr, S., E-mail: suvi.bayr@jyu.fi; Ojanperä, M.; Kaparaju, P.; Rintala, J.

    2014-10-15

    Highlights: • Rendering wastes’ mono-digestion and co-digestion with potato pulp were studied. • CSTR process with OLR of 1.5 kg VS/m{sup 3} d, HRT of 50 d was unstable in mono-digestion. • Free NH{sub 3} inhibited mono-digestion of rendering wastes. • CSTR process with OLR of 1.5 kg VS/m{sup 3} d, HRT of 50 d was stable in co-digestion. • Co-digestion increased methane yield somewhat compared to mono-digestion. - Abstract: In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55 °C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH{sub 4}-N and/or free NH{sub 3}) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m{sup 3} d and hydraulic retention time (HRT) of 50 d was unstable and resulted in methane yields of 450 dm{sup 3}/kg VS{sub fed}. On the other hand, co-digestion of rendering wastes with potato pulp (60% wet weight, WW) at the same OLR and HRT improved the process stability and increased methane yields (500–680 dm{sup 3}/kg VS{sub fed}). Thus, it can be concluded that co-digestion of rendering wastes with potato pulp could improve the process stability and methane yields from these difficult to treat industrial waste materials.

  11. [Hybrid 3-D rendering of the thorax and surface-based virtual bronchoscopy in surgical and interventional therapy control].

    Science.gov (United States)

    Seemann, M D; Gebicke, K; Luboldt, W; Albes, J M; Vollmar, J; Schäfer, J F; Beinert, T; Englmeier, K H; Bitzer, M; Claussen, C D

    2001-07-01

    The aim of this study was to demonstrate the possibilities of a hybrid rendering method, the combination of a color-coded surface and volume rendering method, with the feasibility of performing surface-based virtual endoscopy with different representation models in the operative and interventional therapy control of the chest. In 6 consecutive patients with partial lung resection (n = 2) and lung transplantation (n = 4) a thin-section spiral computed tomography of the chest was performed. The tracheobronchial system and the introduced metallic stents were visualized using a color-coded surface rendering method. The remaining thoracic structures were visualized using a volume rendering method. For virtual bronchoscopy, the tracheobronchial system was visualized using a triangle surface model, a shaded-surface model and a transparent shaded-surface model. The hybrid 3D visualization uses the advantages of both the color-coded surface and volume rendering methods and facilitates a clear representation of the tracheobronchial system and the complex topographical relationship of morphological and pathological changes without loss of diagnostic information. Performing virtual bronchoscopy with the transparent shaded-surface model facilitates a reasonable to optimal, simultaneous visualization and assessment of the surface structure of the tracheobronchial system and the surrounding mediastinal structures and lesions. Hybrid rendering relieve the morphological assessment of anatomical and pathological changes without the need for time-consuming detailed analysis and presentation of source images. Performing virtual bronchoscopy with a transparent shaded-surface model offers a promising alternative to flexible fiberoptic bronchoscopy.

  12. Real-time 3-dimensional fetal echocardiography with an instantaneous volume-rendered display: early description and pictorial essay.

    Science.gov (United States)

    Sklansky, Mark S; DeVore, Greggory R; Wong, Pierre C

    2004-02-01

    Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.

  13. Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair.

    Science.gov (United States)

    Agren, M S; Rasmussen, K; Pakkenberg, B; Jørgensen, B

    2014-07-01

    Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays. The number of leucocytes and erythrocytes was reduced (P platelets increased (P fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P platelet-derived growth factor (PDGF)-AB [2·5-fold, P PDGF-BB [1·6-fold, P vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications. © 2013 International Society of Blood Transfusion.

  14. Transforming growth factor type β can act as a potent competence factor for AKR-2B cells

    International Nuclear Information System (INIS)

    Goustin, A.S.; Nuttall, G.A.; Leof, E.B.; Ranganathan, G.; Moses, H.L.

    1987-01-01

    Transforming growth factor type β (TGFβ) is a pleiotropic regulator of cell growth with specific high-affinity cell-surface receptors on a large number of cells; its mechanism of action, however, is poorly defined. In this report, the authors utilized the mouse fibroblast line AKR-2B to explore the question of the temporal requirements during the cell cycle in regard to both the growth inhibitory and the growth stimulatory action of TGFβ. The results indicate that AKR-2B cells are most sensitive to the inhibitory action of TGFβ during early to mid-G 1 . In addition, TGFβ need be present only briefly in order to exert its inhibitory effect on EGF-induced DNA synthesis. Likewise, the stimulatory effect of TGFβ in the absence of EGF requires only an equally brief exposure to TGFβ. Use of homogeneous 125 I-labeled TGFβ in a cell-binding assay demonstrates that TGFβ bound to cell-surface receptors can readily exchange into the culture medium, helping to rule out the possibility that persistent receptor-bound TGFβ is the source of a continuous stimulus. The data indicate that TGFβ exposure induces a stable state in the cell similar to but distinct from the state of competence induced by platelet-derived growth factor (PDGF)

  15. Regulation of insulin-like growth factor I receptors on vascular smooth muscle cells by growth factors and phorbol esters.

    Science.gov (United States)

    Ververis, J J; Ku, L; Delafontaine, P

    1993-06-01

    Insulin-like growth factor I (IGF I) is an important mitogen for vascular smooth muscle cells. To characterize regulation of vascular IGF I receptors, we performed radioligand displacement experiments using rat aortic smooth muscle cells (RASMs). Serum deprivation for 48 hours caused a 40% decrease in IGF I receptor number. Exposure of quiescent RASMs to platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), or angiotensin II (Ang II) caused a 1.5-2.0-fold increase in IGF I receptors per cell. After FGF exposure, there was a marked increase in the mitogenic response to IGF I. IGF I downregulated its receptors in the presence of platelet-poor plasma. Stimulation of protein kinase C (PKC) by exposure of quiescent RASMs to phorbol 12-myristate 13-acetate caused a biphasic response in IGF I binding; there was a 42% decrease in receptor number at 45 minutes and a 238% increase at 24 hours. To determine the role of PKC in growth factor-induced regulation of IGF I receptors, we downregulated PKC by exposing RASMs to phorbol 12,13-dibutyrate (PDBu) for 48 hours. PDGF- and FGF- but not Ang II-mediated upregulation of IGF I receptors was completely inhibited in PDBu-treated cells. Thus, acute PKC activation by phorbol esters inhibits IGF I binding, whereas chronic PKC activation increases IGF I binding. PDGF and FGF but not Ang II regulate vascular IGF I receptors through a PKC-dependent pathway. These data provide new insights into the regulation of vascular smooth muscle cell IGF I receptors in vitro and are of potential importance in characterizing vascular proliferative responses in vivo.

  16. Biomaterials with persistent growth factor gradients in vivo accelerate vascularized tissue formation.

    Science.gov (United States)

    Akar, Banu; Jiang, Bin; Somo, Sami I; Appel, Alyssa A; Larson, Jeffery C; Tichauer, Kenneth M; Brey, Eric M

    2015-12-01

    Gradients of soluble factors play an important role in many biological processes, including blood vessel assembly. Gradients can be studied in detail in vitro, but methods that enable the study of spatially distributed soluble factors and multi-cellular processes in vivo are limited. Here, we report on a method for the generation of persistent in vivo gradients of growth factors in a three-dimensional (3D) biomaterial system. Fibrin loaded porous poly (ethylene glycol) (PEG) scaffolds were generated using a particulate leaching method. Platelet derived growth factor BB (PDGF-BB) was encapsulated into poly (lactic-co-glycolic acid) (PLGA) microspheres which were placed distal to the tissue-material interface. PLGA provides sustained release of PDGF-BB and its diffusion through the porous structure results in gradient formation. Gradients within the scaffold were confirmed in vivo using near-infrared fluorescence imaging and gradients were present for more than 3 weeks. The diffusion of PDGF-BB was modeled and verified with in vivo imaging findings. The depth of tissue invasion and density of blood vessels formed in response to the biomaterial increased with magnitude of the gradient. This biomaterial system allows for generation of sustained growth factor gradients for the study of tissue response to gradients in vivo. Published by Elsevier Ltd.

  17. Platelets promote tumor growth and metastasis via direct interaction between Aggrus/podoplanin and CLEC-2.

    Directory of Open Access Journals (Sweden)

    Satoshi Takagi

    Full Text Available The platelet aggregation-inducing factor Aggrus, also known as podoplanin, is frequently upregulated in several types of tumors and enhances hematogenous metastasis by interacting with and activating the platelet receptor CLEC-2. Thus, Aggrus-CLEC-2 binding could be a therapeutic molecular mechanism for cancer therapy. We generated a new anti-human Aggrus monoclonal antibody, MS-1, that suppressed Aggrus-CLEC-2 binding, Aggrus-induced platelet aggregation, and Aggrus-mediated tumor metastasis. Interestingly, the MS-1 monoclonal antibody attenuated the growth of Aggrus-positive tumors in vivo. Moreover, the humanized chimeric MS-1 antibody, ChMS-1, also exhibited strong antitumor activity against Aggrus-positive lung squamous cell carcinoma xenografted into NOD-SCID mice compromising antibody-dependent cellular cytotoxic and complement-dependent cytotoxic activities. Because Aggrus knockdown suppressed platelet-induced proliferation in vitro and tumor growth of the lung squamous cell carcinoma in vivo, Aggrus may be involved in not only tumor metastasis but also tumor growth by promoting platelet-tumor interaction, platelet activation, and secretion of platelet-derived factors in vivo. Our results indicate that molecular target drugs inhibiting specific platelet-tumor interactions can be developed as antitumor drugs that suppress both metastasis and proliferation of tumors such as lung squamous cell carcinoma.

  18. Growth factor and pro-inflammatory cytokine contents in platelet-rich plasma (PRP), plasma rich in growth factors (PRGF), advanced platelet-rich fibrin (A-PRF), and concentrated growth factors (CGF).

    Science.gov (United States)

    Masuki, Hideo; Okudera, Toshimitsu; Watanebe, Taisuke; Suzuki, Masashi; Nishiyama, Kazuhiko; Okudera, Hajime; Nakata, Koh; Uematsu, Kohya; Su, Chen-Yao; Kawase, Tomoyuki

    2016-12-01

    The development of platelet-rich fibrin (PRF) drastically simplified the preparation procedure of platelet-concentrated biomaterials, such as platelet-rich plasma (PRP), and facilitated their clinical application. PRF's clinical effectiveness has often been demonstrated in pre-clinical and clinical studies; however, it is still controversial whether growth factors are significantly concentrated in PRF preparations to facilitate wound healing and tissue regeneration. To address this matter, we performed a comparative study of growth factor contents in PRP and its derivatives, such as advanced PRF (A-PRF) and concentrated growth factors (CGF). PRP and its derivatives were prepared from the same peripheral blood samples collected from healthy donors. A-PRF and CGF preparations were homogenized and centrifuged to produce extracts. Platelet and white blood cell counts in A-PRF and CGF preparations were determined by subtracting those counts in red blood cell fractions, supernatant acellular serum fractions, and A-PRF/CGF exudate fractions from those counts of whole blood samples. Concentrations of growth factors (TGF-β1, PDGF-BB, VEGF) and pro-inflammatory cytokines (IL-1β, IL-6) were determined using ELISA kits. Compared to PRP preparations, both A-PRF and CGF extracts contained compatible or higher levels of platelets and platelet-derived growth factors. In a cell proliferation assay, both A-PRF and CGF extracts significantly stimulated the proliferation of human periosteal cells without significant reduction at higher doses. These data clearly demonstrate that both A-PRF and CGF preparations contain significant amounts of growth factors capable of stimulating periosteal cell proliferation, suggesting that A-PRF and CGF preparations function not only as a scaffolding material but also as a reservoir to deliver certain growth factors at the site of application.

  19. A Screen Space GPGPU Surface LIC Algorithm for Distributed Memory Data Parallel Sort Last Rendering Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Loring, Burlen; Karimabadi, Homa; Rortershteyn, Vadim

    2014-07-01

    The surface line integral convolution(LIC) visualization technique produces dense visualization of vector fields on arbitrary surfaces. We present a screen space surface LIC algorithm for use in distributed memory data parallel sort last rendering infrastructures. The motivations for our work are to support analysis of datasets that are too large to fit in the main memory of a single computer and compatibility with prevalent parallel scientific visualization tools such as ParaView and VisIt. By working in screen space using OpenGL we can leverage the computational power of GPUs when they are available and run without them when they are not. We address efficiency and performance issues that arise from the transformation of data from physical to screen space by selecting an alternate screen space domain decomposition. We analyze the algorithm's scaling behavior with and without GPUs on two high performance computing systems using data from turbulent plasma simulations.

  20. MRI of the labyrinth with volume rendering for cochlear implants candidates

    International Nuclear Information System (INIS)

    Sakata, Motomichi; Harada, Kuniaki; Shirase, Ryuji; Suzuki, Junpei; Nagahama, Hiroshi

    2009-01-01

    We demonstrated three-dimensional models of the labyrinth by volume rendering (VR) in preoperative assessment for cochlear implantation. MRI data sets were acquired in selected subjects using three-dimensional-fast spin echo sequences (3D-FSE). We produced the three-dimensional models of the labyrinth from axial heavily T2-weighted images. The three-dimensional models distinguished the scala tympani and scala vestibuli and provided multidirectional images. The optimal threshold three-dimensional models clearly showed the focal region of signal loss in the cochlear turns (47.1%) and the presence of inner ear anomalies (17.3%) in our series of patients. This study was concluded that these three-dimensional models by VR provide the oto-surgeon with precise, detailed, and easily interpreted information about the cochlear turns for cochlear implants candidates. (author)

  1. Screen Space Ambient Occlusion Based Multiple Importance Sampling for Real-Time Rendering

    Science.gov (United States)

    Zerari, Abd El Mouméne; Babahenini, Mohamed Chaouki

    2018-03-01

    We propose a new approximation technique for accelerating the Global Illumination algorithm for real-time rendering. The proposed approach is based on the Screen-Space Ambient Occlusion (SSAO) method, which approximates the global illumination for large, fully dynamic scenes at interactive frame rates. Current algorithms that are based on the SSAO method suffer from difficulties due to the large number of samples that are required. In this paper, we propose an improvement to the SSAO technique by integrating it with a Multiple Importance Sampling technique that combines a stratified sampling method with an importance sampling method, with the objective of reducing the number of samples. Experimental evaluation demonstrates that our technique can produce high-quality images in real time and is significantly faster than traditional techniques.

  2. Rendering Intelligence at Physical Layer for Smart Addressing and Multiple Access

    DEFF Research Database (Denmark)

    Sanyal, Rajarshi; Prasad, Ramjee; Cianca, Ernestina

    2010-01-01

    addressing of a node. For a typical closed user group type of network, we propose a multiple access mechanism and network topology which will not only eliminate the need of intelligent core network equipments in the network area , but to use this intelligent physical layer to directly reach any node over......The primary objective of this work is to propose a technique of wireless communication, where we render intelligence to the physical layer. We aim to realize a physical layer that can take part in some processes which is otherwise confined to higher layer signalling activities, like for example...... the fundamentals behind the proposed multiple access scheme and draws out the benefits compared to the existing multiple access processes based on cellular approach....

  3. Chromium: A Stress-Processing Framework for Interactive Rendering on Clusters

    International Nuclear Information System (INIS)

    Humphreys, G.; Houston, M.; Ng, Y.-R.; Frank, R.; Ahern, S.; Kirchner, P.D.; Klosowski, J.T.

    2002-01-01

    We describe Chromium, a system for manipulating streams of graphics API commands on clusters of workstations. Chromium's stream filters can be arranged to create sort-first and sort-last parallel graphics architectures that, in many cases, support the same applications while using only commodity graphics accelerators. In addition, these stream filters can be extended programmatically, allowing the user to customize the stream transformations performed by nodes in a cluster. Because our stream processing mechanism is completely general, any cluster-parallel rendering algorithm can be either implemented on top of or embedded in Chromium. In this paper, we give examples of real-world applications that use Chromium to achieve good scalability on clusters of workstations, and describe other potential uses of this stream processing technology. By completely abstracting the underlying graphics architecture, network topology, and API command processing semantics, we allow a variety of applications to run in different environments

  4. The Role of the Patrimonial Result Account in Rendering Performance in the Secondary Educational Institutions

    Directory of Open Access Journals (Sweden)

    Daniela Vitan

    2016-01-01

    Full Text Available Through its tools, in particular through patrimonial result account, accounting gives information about the performance in the secondary educational institutions and beyond. In the work ”Informational valence regarding the role of the patrimonial result account in rendering performance at secondary educational institutions” it is presented an analysis model of the performance in the pre-university education institutions based on the economic-financial indicators. These indicator simply an analysis of the dynamics and structure of revenues, costs, results and enable the knowledge of the resource management in order to cover expenses from the revenue, their evolution and their total balance. The analysis was based on hypothetical data over a period of two years, and after this period it was determined that the institution has managed to maintain its level of efficiency in resource management.

  5. Feed-forward volume rendering algorithm for moderately parallel MIMD machines

    Science.gov (United States)

    Yagel, Roni

    1993-01-01

    Algorithms for direct volume rendering on parallel and vector processors are investigated. Volumes are transformed efficiently on parallel processors by dividing the data into slices and beams of voxels. Equal sized sets of slices along one axis are distributed to processors. Parallelism is achieved at two levels. Because each slice can be transformed independently of others, processors transform their assigned slices with no communication, thus providing maximum possible parallelism at the first level. Within each slice, consecutive beams are incrementally transformed using coherency in the transformation computation. Also, coherency across slices can be exploited to further enhance performance. This coherency yields the second level of parallelism through the use of the vector processing or pipelining. Other ongoing efforts include investigations into image reconstruction techniques, load balancing strategies, and improving performance.

  6. Scene reassembly after multimodal digitization and pipeline evaluation using photorealistic rendering

    DEFF Research Database (Denmark)

    Stets, Jonathan Dyssel; Dal Corso, Alessandro; Nielsen, Jannik Boll

    2017-01-01

    of the lighting environment. This enables pixelwise comparison of photographs of the real scene with renderings of the digital version of the scene. Such quantitative evaluation is useful for verifying acquired material appearance and reconstructed surface geometry, which is an important aspect of digital content......Transparent objects require acquisition modalities that are very different from the ones used for objects with more diffuse reflectance properties. Digitizing a scene where objects must be acquired with different modalities requires scene reassembly after reconstruction of the object surfaces....... This reassembly of a scene that was picked apart for scanning seems unexplored. We contribute with a multimodal digitization pipeline for scenes that require this step of reassembly. Our pipeline includes measurement of bidirectional reflectance distribution functions and high dynamic range imaging...

  7. Color design model of high color rendering index white-light LED module.

    Science.gov (United States)

    Ying, Shang-Ping; Fu, Han-Kuei; Hsieh, Hsin-Hsin; Hsieh, Kun-Yang

    2017-05-10

    The traditional white-light light-emitting diode (LED) is packaged with a single chip and a single phosphor but has a poor color rendering index (CRI). The next-generation package comprises two chips and a single phosphor, has a high CRI, and retains high luminous efficacy. This study employs two chips and two phosphors to improve the diode's color tunability with various proportions of two phosphors and various densities of phosphor in the silicone used. A color design model is established for color fine-tuning of the white-light LED module. The maximum difference between the measured and color-design-model simulated CIE 1931 color coordinates is approximately 0.0063 around a correlated color temperature (CCT) of 2500 K. This study provides a rapid method to obtain the color fine-tuning of a white-light LED module with a high CRI and luminous efficacy.

  8. Three-dimensional range data compression using computer graphics rendering pipeline.

    Science.gov (United States)

    Zhang, Song

    2012-06-20

    This paper presents the idea of naturally encoding three-dimensional (3D) range data into regular two-dimensional (2D) images utilizing computer graphics rendering pipeline. The computer graphics pipeline provides a means to sample 3D geometry data into regular 2D images, and also to retrieve the depth information for each sampled pixel. The depth information for each pixel is further encoded into red, green, and blue color channels of regular 2D images. The 2D images can further be compressed with existing 2D image compression techniques. By this novel means, 3D geometry data obtained by 3D range scanners can be instantaneously compressed into 2D images, providing a novel way of storing 3D range data into its 2D counterparts. We will present experimental results to verify the performance of this proposed technique.

  9. Can thiolation render a low molecular weight polymer of just 20-kDa mucoadhesive?

    Science.gov (United States)

    Mahmood, Arshad; Bonengel, Sonja; Laffleur, Flavia; Ijaz, Muhammad; Idrees, Muneeb Ahmad; Hussain, Shah; Huck, Christian W; Matuszczak, Barbara; Bernkop-Schnürch, Andreas

    2016-01-01

    The objective was to investigate whether even low-molecular weight polymers (LMWPs) can be rendered mucoadhesive due to thiolation. Interceded by the double catalytic system carbodiimide/N-hydroxysuccinimide, cysteamine was covalently attached to a copolymer, poly(4-styrenesulfonic acid-co-maleic acid) (PSSA-MA) exhibiting a molecular weight of just 20 kDa. Depending on the amount of added N-hydroxysuccinimide and cysteamine, the resulting PSSA-MA-cysteamine (PC) conjugates exhibited increasing degree of thiolation, highest being "PC 2300" exhibiting 2300.16 ± 149.86 μmol thiol groups per gram of polymer (mean ± SD; n = 3). This newly developed thiolated polymer was evaluated regarding mucoadhesive, rheological and drug release properties as well from the toxicological point of view. Swelling behavior in 100 mM phosphate buffer pH 6.8 was improved up to 180-fold. Furthermore, due to thiolation, the mucoadhesive properties of the polymer were 240-fold improved. Rheological measurements of polymer/mucus mixtures confirmed results obtained by mucoadhesion studies. In comparison to unmodified polymer, PC 2300 showed 2.3-, 2.3- and 2.4-fold increase in dynamic viscosity, elastic modulus and viscous modulus, respectively. Sustained release of the model drug codeine HCl out of the thiomer was provided for 2.5 h (p polymer. Moreover, the thiomer was found non-toxic over Caco-2 cells for a period of 6- and 24-h exposure. Findings of the present study provide evidence that due to thiolation LMWPs can be rendered highly mucoadhesive as well as cohesive and that a controlled drug release out of such polymers can be provided.

  10. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.T.C. [Univ. of California, San Francisco, CA (United States)

    1997-02-01

    The purpose of this presentation is to discuss the computer processing techniques of tomographic images, after they have been generated by imaging scanners, for volume visualization. Volume visualization is concerned with the representation, manipulation, and rendering of volumetric data. Since the first digital images were produced from computed tomography (CT) scanners in the mid 1970s, applications of visualization in medicine have expanded dramatically. Today, three-dimensional (3D) medical visualization has expanded from using CT data, the first inherently digital source of 3D medical data, to using data from various medical imaging modalities, including magnetic resonance scanners, positron emission scanners, digital ultrasound, electronic and confocal microscopy, and other medical imaging modalities. We have advanced from rendering anatomy to aid diagnosis and visualize complex anatomic structures to planning and assisting surgery and radiation treatment. New, more accurate and cost-effective procedures for clinical services and biomedical research have become possible by integrating computer graphics technology with medical images. This trend is particularly noticeable in current market-driven health care environment. For example, interventional imaging, image-guided surgery, and stereotactic and visualization techniques are now stemming into surgical practice. In this presentation, we discuss only computer-display-based approaches of volumetric medical visualization. That is, we assume that the display device available is two-dimensional (2D) in nature and all analysis of multidimensional image data is to be carried out via the 2D screen of the device. There are technologies such as holography and virtual reality that do provide a {open_quotes}true 3D screen{close_quotes}. To confine the scope, this presentation will not discuss such approaches.

  11. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    International Nuclear Information System (INIS)

    Wong, S.T.C.

    1997-01-01

    The purpose of this presentation is to discuss the computer processing techniques of tomographic images, after they have been generated by imaging scanners, for volume visualization. Volume visualization is concerned with the representation, manipulation, and rendering of volumetric data. Since the first digital images were produced from computed tomography (CT) scanners in the mid 1970s, applications of visualization in medicine have expanded dramatically. Today, three-dimensional (3D) medical visualization has expanded from using CT data, the first inherently digital source of 3D medical data, to using data from various medical imaging modalities, including magnetic resonance scanners, positron emission scanners, digital ultrasound, electronic and confocal microscopy, and other medical imaging modalities. We have advanced from rendering anatomy to aid diagnosis and visualize complex anatomic structures to planning and assisting surgery and radiation treatment. New, more accurate and cost-effective procedures for clinical services and biomedical research have become possible by integrating computer graphics technology with medical images. This trend is particularly noticeable in current market-driven health care environment. For example, interventional imaging, image-guided surgery, and stereotactic and visualization techniques are now stemming into surgical practice. In this presentation, we discuss only computer-display-based approaches of volumetric medical visualization. That is, we assume that the display device available is two-dimensional (2D) in nature and all analysis of multidimensional image data is to be carried out via the 2D screen of the device. There are technologies such as holography and virtual reality that do provide a open-quotes true 3D screenclose quotes. To confine the scope, this presentation will not discuss such approaches

  12. 3D reconstruction from X-ray fluoroscopy for clinical veterinary medicine using differential volume rendering

    International Nuclear Information System (INIS)

    Khongsomboon, K.; Hamamoto, Kazuhiko; Kondo, Shozo

    2007-01-01

    3D reconstruction from ordinary X-ray equipment which is not CT or MRI is required in clinical veterinary medicine. Authors have already proposed a 3D reconstruction technique from X-ray photograph to present bone structure. Although the reconstruction is useful for veterinary medicine, the technique has two problems. One is about exposure of X-ray and the other is about data acquisition process. An x-ray equipment which is not special one but can solve the problems is X-ray fluoroscopy. Therefore, in this paper, we propose a method for 3D-reconstruction from X-ray fluoroscopy for clinical veterinary medicine. Fluoroscopy is usually used to observe a movement of organ or to identify a position of organ for surgery by weak X-ray intensity. Since fluoroscopy can output a observed result as movie, the previous two problems which are caused by use of X-ray photograph can be solved. However, a new problem arises due to weak X-ray intensity. Although fluoroscopy can present information of not only bone structure but soft tissues, the contrast is very low and it is very difficult to recognize some soft tissues. It is very useful to be able to observe not only bone structure but soft tissues clearly by ordinary X-ray equipment in the field of clinical veterinary medicine. To solve this problem, this paper proposes a new method to determine opacity in volume rendering process. The opacity is determined according to 3D differential coefficient of 3D reconstruction. This differential volume rendering can present a 3D structure image of multiple organs volumetrically and clearly for clinical veterinary medicine. This paper shows results of simulation and experimental investigation of small dog and evaluation by veterinarians. (author)

  13. 3D-shaded surface rendering of gadolinium-enhanced MR angiography in congenital heart disease

    International Nuclear Information System (INIS)

    Okuda, S.; Kikinis, R.; Dumanli, H.; Geva, T.; Powell, A.J.; Chung, T.

    2000-01-01

    Background. Gadolinium-enhanced three-dimensional (3D) MR angiography is a useful imaging technique for patients with congenital heart disease. Objective. This study sought to determine the added value of creating 3D shaded surface displays compared to standard maximal intensity projection (MIP) and multiplanar reformatting (MPR) techniques when analyzing 3D MR angiography data. Materials and methods. Seventeen patients (range, 3 months to 51 years old) with a variety of congenital cardiovascular defects underwent gadolinium-enhanced 3D MR angiography of the thorax. Color-coded 3D shaded surface models were rendered from the image data using manual segmentation and computer-based algorithms. Models could be rotated, translocated, or zoomed interactively by the viewer. Information available from the 3D models was compared to analysis based on viewing standard MIP/MPR displays. Results. Median postprocessing time for the 3D models was 6 h (range, 3-25 h) compared to approximately 20 min for MIP/MPR viewing. No additional diagnostic information was gained from 3D model analysis. All major findings with MIP/MPR postprocessing were also apparent on the 3D models. Qualitatively, the 3D models were more easily interpreted and enabled adjacent vessels to be distinguished more readily. Conclusion. Routine use of 3D shaded surface reconstructions for visualization of contrast enhanced MR angiography in congenital heart disease cannot be recommended. 3D surface rendering may be more useful for presenting complex anatomy to an audience unfamiliar with congenital heart disease and as an educational tool. (orig.)

  14. Immunohistochemical study of the growth factors, aFGF, bFGF, PDGF-AB, VEGF-A and its receptor (Flk-1) during arteriogenesis.

    Science.gov (United States)

    Wu, Song; Wu, Xiaoqiong; Zhu, Wu; Cai, Wei-Jun; Schaper, Jutta; Schaper, Wolfgang

    2010-10-01

    Growth factors are viewed as main arteriogenic stimulators for collateral vessel growth. However, the information about their native expression and distribution in collateral vessels is still limited. This study was designed to profile expression of acidic and basic FGF, platelet-derived growth factor (PDGF-AB) and vascular endothelial growth factor (VEGF-A) and its receptor, fetal liver kinase-1 (Flk-1) during arteriogenesis by confocal immunofluorescence in both dog ameroid constrictor model and rabbit arteriovenous shunt model of arteriogenesis. We found that: (1) in normal arteries (NA) in dog heart, aFGF, bFGF, and PDGF-AB all were mainly expressed in endothelial cells (EC) and media smooth muscle cells (SMC), but the expression of aFGF was very weak, with those of the other two being moderate; (2) in collateral arteries (CAs), aFGF, bFGF, and PDGF-AB all were significantly upregulated (P growth factors, aFGF, bFGF, and PDGF-AB are significantly upregulated in collateral vessels in dog heart, and enhanced VEGF-A and its receptor, Flk-1, are associated with rapid and lasting increased shear stress. These findings suggest that endogenous production of growth factors could be an important factor promoting collateral vessel growth.

  15. Diagnostic Accuracy of the Volume Rendering Images of Multi-Detector CT for the Detection of Lumbar Transverse Process Fractures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Hak; Chun, Tong Jin [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of)

    2012-01-15

    To compare the accuracy of three-dimensional computed tomographic (3D CT) volume rendering techniques with axial images of multi-detector row computed tomography to identify lumbar transverse process (LTP) fractures in trauma patients. We retrospectively evaluated 42 patients with back pain as a result of blunt trauma between January and June of 2010. Two radiologists examined the 3D CT volume rendering images independently. The confirmation of a LTP fracture was based on the consensus of the axial images by the two radiologists. The results of 3D CT volume rendering images were compared with the axial images and the diagnostic powers (sensitivity, specificity, and accuracy) were calculated. Seven of the 42 patients had twenty five lumbar transverse process fractures. The diagnostic power of the 3D CT volume rendering technique is as accurate as axial images. Reader 1, sensitivity 96%, specificity 100%, accuracy 99.9%; and Reader 2 sensitivity 100%, specificity 99.8%, accuracy 99.8%. The accordance of the two radiologists was 99.8%. 3D CT volume rendering images can alternate axial images to detect lumbar transverse process fractures with good image quality.

  16. A Comparison Study of Growth Factor Expression following Treatment with Transcutaneous Electrical Nerve Stimulation, Saline Solution, Povidone-Iodine, and Lavender Oil in Wounds Healing

    Directory of Open Access Journals (Sweden)

    Adalet Koca Kutlu

    2013-01-01

    Full Text Available This study compared the effects of transcutaneous electrical nerve stimulation (TENS, saline solution (SS, povidone-iodine (PI, and lavender oil (Lavandula angustifolia through expression of growth factors in a rat model of wound healing. Six experimental groups were established, each containing 8 rats: a healthy group with no incision wounds, an incision-control group, an incision and TENS group, an incision and SS group, an incision and PI group, and an incision and lavender oil group. Experiments continued for 5 days, after which the skin in the excision area was removed. Tissue concentrations of epidermal growth factor (EGF and platelet-derived growth factor (PDGF-A were measured using enzyme-linked immunosorbent assay (ELISA. Tissue expressions of EGF, PDGF-A, and fibroblast growth factor (FGF-2 were determined using immunohistochemistry. Wound closure progressed more rapidly in the TENS and lavender oil groups than in the control and other study groups. In particular, PDGF-A expressions in the dermis and EGF expression in the epidermis were significantly intense in the TENS group (P<0.05. In addition, ELISA levels of growth factors such as PDGF-A and EGF were significantly higher in TENS group compared to the control group (P<0.05. These immunohistochemical and ELISA results suggest that TENS may improve wound healing through increasing growth factors in the dermis and epidermis more than other topical applications.

  17. Influence of storage conditions on the release of growth factors in platelet-rich blood derivatives

    Directory of Open Access Journals (Sweden)

    Düregger Katharina

    2016-09-01

    Full Text Available Thrombocytes can be concentrated in blood derivatives and used as autologous transplants e.g. for wound treatment due to the release of growth factors such as platelet derived growth factor (PDGF. Conditions for processing and storage of these platelet-rich blood derivatives influence the release of PDGF from the platelet-bound α-granules into the plasma. In this study Platelet rich plasma (PRP and Platelet concentrate (PC were produced with a fully automated centrifugation system. Storage of PRP and PC for 1 h up to 4 months at temperatures between −20°C and +37°C was applied with the aim of evaluating the influence on the amount of released PDGF. Storage at −20°C resulted in the highest release of PDGF in PRP and a time dependency was determined: prolonged storage up to 1 month in PRP and 10 days in PC increased the release of PDGF. Regardless of the storage conditions, the release of PDGF per platelet was higher in PC than in PRP.

  18. Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

    Science.gov (United States)

    Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

    2016-03-01

    We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

  19. Virtual Whipple: preoperative surgical planning with volume-rendered MDCT images to identify arterial variants relevant to the Whipple procedure.

    Science.gov (United States)

    Brennan, Darren D; Zamboni, Giulia; Sosna, Jacob; Callery, Mark P; Vollmer, Charles M V; Raptopoulos, Vassilios D; Kruskal, Jonathan B

    2007-05-01

    The purposes of this study were to combine a thorough understanding of the technical aspects of the Whipple procedure with advanced rendering techniques by introducing a virtual Whipple procedure and to evaluate the utility of this new rendering technique in prediction of the arterial variants that cross the anticipated surgical resection plane. The virtual Whipple is a novel technique that follows the complex surgical steps in a Whipple procedure. Three-dimensional reconstructed angiographic images are used to identify arterial variants for the surgeon as part of the preoperative radiologic assessment of pancreatic and ampullary tumors.

  20. Correlation between increasing tissue ischemia and circulating levels of angiogenic growth factors in peripheral artery disease.

    Science.gov (United States)

    Jalkanen, Juho; Hautero, Olli; Maksimow, Mikael; Jalkanen, Sirpa; Hakovirta, Harri

    2018-04-21

    The aim of the present study was to assess the circulating levels of vascular endothelial growth factor (VEGF) and other suggested therapeutic growth factors with the degree of ischemia in patients with different clinical manifestations of peripheral arterial disease (PAD) according to the Rutherford grades. The study cohort consists of 226 consecutive patients admitted to a Department of Vascular Surgery for elective invasive procedures. PAD patients were grouped according to the Rutherford grades after a clinical assessment. Ankle-brachial pressure indices (ABI) and absolute toe pressure (TP) values were measured. Serum levels of circulating VEGF, hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) were measured from serum and analysed against Rutherford grades and peripheral hemodynamic measurements. The levels of VEGF (P = 0.009) and HGF (P correlations between Rutherford grades was detected as follows; VEGF (Pearson's correlation = 0.183, P = 0.004), HGF (Pearson's correlation = 0.253, P Pearson's correlation = 0.169, P = 0.008) and PDGF (Pearson's correlation = 0.296, P correlation with ABI (Pearson's correlation -0.19, P = 0.009) and TP (Pearson's correlation -0.20, P = 0.005) measurements. Our present observations show that the circulating levels of VEGF and other suggested therapeutic growth factors are significantly increased along with increasing ischemia. These findings present a new perspective to anticipated positive effects of gene therapies utilizing VEGF, HGF, and bFGF, because the levels of these growth factors are endogenously high in end-stage PAD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. A Study of Layout, Rendering, and Interaction Methods for Immersive Graph Visualization.

    Science.gov (United States)

    Kwon, Oh-Hyun; Muelder, Chris; Lee, Kyungwon; Ma, Kwan-Liu

    2016-07-01

    Information visualization has traditionally limited itself to 2D representations, primarily due to the prevalence of 2D displays and report formats. However, there has been a recent surge in popularity of consumer grade 3D displays and immersive head-mounted displays (HMDs). The ubiquity of such displays enables the possibility of immersive, stereoscopic visualization environments. While techniques that utilize such immersive environments have been explored extensively for spatial and scientific visualizations, contrastingly very little has been explored for information visualization. In this paper, we present our considerations of layout, rendering, and interaction methods for visualizing graphs in an immersive environment. We conducted a user study to evaluate our techniques compared to traditional 2D graph visualization. The results show that participants answered significantly faster with a fewer number of interactions using our techniques, especially for more difficult tasks. While the overall correctness rates are not significantly different, we found that participants gave significantly more correct answers using our techniques for larger graphs.

  2. Rendering Systems Visible for Design: Synthesis Maps as Constructivist Design Narratives

    Directory of Open Access Journals (Sweden)

    Peter Jones

    Full Text Available Synthesis maps integrate research evidence, system expertise, and design proposals into visual narratives. These narratives support communication and decision-making among stakeholders. Synthesis maps evolved from earlier visualization tools in systemics and design. They help stakeholders to understand design options for complex sociotechnical systems. Other visual approaches map complexity for effective collaboration across perspectives and knowledge domains. These help stakeholder groups to work in higher-order design contexts for sociotechnical or human-ecological systems. This article describes a constructivist pedagogy for collaborative learning in small teams of mixed-discipline designers. Synthesis mapping enables these teams to learn systems methods for design research in complex problem domains. Synthesis maps integrate knowledge from research cycles and iterative sensemaking to define a coherent design narrative. While synthesis maps may include formal system modeling techniques, they do not require them. Synthesis maps tangibly render research observations and design choices. As a hybrid system design method, synthesis maps are a contribution to the design genre of visual systems thinking.

  3. In-Situ Three-Dimensional Shape Rendering from Strain Values Obtained Through Optical Fiber Sensors

    Science.gov (United States)

    Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

    2015-01-01

    A method and system for rendering the shape of a multi-core optical fiber or multi-fiber bundle in three-dimensional space in real time based on measured fiber strain data. Three optical fiber cores arc arranged in parallel at 120.degree. intervals about a central axis. A series of longitudinally co-located strain sensor triplets, typically fiber Bragg gratings, are positioned along the length of each fiber at known intervals. A tunable laser interrogates the sensors to detect strain on the fiber cores. Software determines the strain magnitude (.DELTA.L/L) for each fiber at a given triplet, but then applies beam theory to calculate curvature, beading angle and torsion of the fiber bundle, and from there it determines the shape of the fiber in s Cartesian coordinate system by solving a series of ordinary differential equations expanded from the Frenet-Serrat equations. This approach eliminates the need for computationally time-intensive curve-tilting and allows the three-dimensional shape of the optical fiber assembly to be displayed in real-time.

  4. Clinical Recommendations on Emergency Medical Care Rendering to Children with Acute Intoxication

    Directory of Open Access Journals (Sweden)

    A. A. Baranov

    2015-01-01

    Full Text Available The article is dedicated to the issue of intoxication in children. Acute accidental intoxication appears to be especially relevant for pediatric practice. Drugs, various chemicals frequently used in everyday life and in farming, as well as animal poisons, including snake poisons, may have a toxic effect on children. Specialists of professional associations of physicians “Russian Society of Emergency Medicine” and pediatricians “Union of Pediatricians of Russia” formulated and briefly described the main causes of acute intoxication in children, clinical manifestations and the most significant laboratory indicators of toxic manifestations for various substances, as well as therapy principles and algorithms for such conditions in compliance with principles of the evidence-based medicine. The article presents pathognomonic symptoms and peculiarities of drug intoxication, provides a description of mediator symptoms of intoxication with various substances, as well as the symptoms that may indicate toxic effect. The article contains a description of principles of correction of vital body functions, measures for removing toxic substances from the body and information on the main antidotes. Special attention is given to the most frequent types of intoxication (with organic acids, lye, naphazoline, paracetamol, snake poisons [viper bite]. The article lists stage of medical care rendering to children suffering from acute intoxication and presents prognosis and further management of pediatric patients suffering from such conditions. 

  5. Transcriptional Changes during Naturally Acquired Zika Virus Infection Render Dendritic Cells Highly Conducive to Viral Replication.

    Science.gov (United States)

    Sun, Xiaoming; Hua, Stephane; Chen, Hsiao-Rong; Ouyang, Zhengyu; Einkauf, Kevin; Tse, Samantha; Ard, Kevin; Ciaranello, Andrea; Yawetz, Sigal; Sax, Paul; Rosenberg, Eric S; Lichterfeld, Mathias; Yu, Xu G

    2017-12-19

    Although dendritic cells are among the human cell population best equipped for cell-intrinsic antiviral immune defense, they seem highly susceptible to infection with the Zika virus (ZIKV). Using highly purified myeloid dendritic cells isolated from individuals with naturally acquired acute infection, we here show that ZIKV induces profound perturbations of transcriptional signatures relative to healthy donors. Interestingly, we noted a remarkable downregulation of antiviral interferon-stimulated genes and innate immune sensors, suggesting that ZIKV can actively suppress interferon-dependent immune responses. In contrast, several host factors known to support ZIKV infection were strongly upregulated during natural ZIKV infection; these transcripts included AXL, the main entry receptor for ZIKV; SOCS3, a negative regulator of ISG expression; and IDO-1, a recognized inducer of regulatory T cell responses. Thus, during in vivo infection, ZIKV can transform the transcriptome of dendritic cells in favor of the virus to render these cells highly conducive to ZIKV infection. Published by Elsevier Inc.

  6. Seeing More by Showing Less: Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization.

    Directory of Open Access Journals (Sweden)

    Chantal M W Tax

    Full Text Available Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI approaches that can also model "crossing fibers", the complexity of the fiber network as reconstructed with tractography has increased tremendously. Many pathways interdigitate and overlap, which hampers an unequivocal 3D visualization of the network and impedes an efficient study of its organization. We propose a novel fiber tractography visualization approach that interactively and selectively adapts the transparency rendering of fiber trajectories as a function of their orientation to enhance the visibility of the spatial context. More specifically, pathways that are oriented (locally or globally along a user-specified opacity axis can be made more transparent or opaque. This substantially improves the 3D visualization of the fiber network and the exploration of tissue configurations that would otherwise be largely covered by other pathways. We present examples of fiber bundle extraction and neurosurgical planning cases where the added benefit of our new visualization scheme is demonstrated over conventional fiber visualization approaches.

  7. Interactive definition of transfer functions in volume rendering based on image markers

    International Nuclear Information System (INIS)

    Teistler, Michael; Nowinski, Wieslaw L.; Breiman, Richard S.; Liong, Sauw Ming; Ho, Liang Yoong; Shahab, Atif

    2007-01-01

    Objectives A user interface for transfer function (TF) definition in volume rendering (VR) was developed that allows the user to intuitively assign color and opacity to the original image intensities. This software may surpass solutions currently deployed in clinical practice by simplifying the use of TFs beyond predefined settings that are not always applicable. Materials and methods The TF definition is usually a cumbersome task that requires the user to manipulate graphical representations of the TF (e.g. trapezoids). A new method that allows the user to place markers at points of interest directly on CT and MRI images or orthogonal reformations was developed based on two-dimensional region growing and a few user-definable marker-related parameters. For each user defined image marker, a segment of the transfer function is computed. The resulting TF can also be applied to the slice image views. Results were judged subjectively. Results Each individualized TF can be defined interactively in a few simple steps. For every user interaction, immediate visual feedback is given. Clinicians who tested the application appreciated being able to directly work on familiar slice images to generate the desired 3D views. Conclusion Interactive TF definition can increase the actual utility of VR, help to understand the role of the TF with its variations, and increase the acceptance of VR as a clinical tool. (orig.)

  8. Common crus aplasia: diagnosis by 3D volume rendering imaging using 3DFT-CISS sequence

    International Nuclear Information System (INIS)

    Kim, H.J.; Song, J.W.; Chon, K.-M.; Goh, E.-K.

    2004-01-01

    AIM: The purpose of this study was to evaluate the findings of three-dimensional (3D) volume rendering (VR) imaging in common crus aplasia (CCA) of the inner ear. MATERIALS AND METHODS: Using 3D VR imaging of temporal bone constructive interference in steady state (CISS) magnetic resonance (MR) images, we retrospectively reviewed seven inner ears of six children who were candidates for cochlear implants and who had been diagnosed with CCA. As controls, we used the same method to examine 402 inner ears of 201 patients who had no clinical symptoms or signs of sensorineural hearing loss. Temporal bone MR imaging (MRI) was performed with a 1.5 T MR machine using a CISS sequence, and VR of the inner ear was performed on a work station. Morphological image analysis was performed on rotation views of 3D VR images. RESULTS: In all seven cases, CCA was diagnosed by the absence of the common crus. The remaining superior semicircular canal (SCC) was normal in five and hypoplastic in two inner ears, while the posterior SCC was normal in all seven. One patient showed bilateral symmetrical CCA. Complicated combined anomalies were seen in the cochlea, vestibule and lateral SCC. CONCLUSION: 3D VR imaging findings with MR CISS sequence can directly diagnose CCA. This technique may be useful in delineating detailed anomalies of SCCs

  9. Painterly rendered portraits from photographs using a knowledge-based approach

    Science.gov (United States)

    DiPaola, Steve

    2007-02-01

    Portrait artists using oils, acrylics or pastels use a specific but open human vision methodology to create a painterly portrait of a live sitter. When they must use a photograph as source, artists augment their process, since photographs have: different focusing - everything is in focus or focused in vertical planes; value clumping - the camera darkens the shadows and lightens the bright areas; as well as color and perspective distortion. In general, artistic methodology attempts the following: from the photograph, the painting must 'simplify, compose and leave out what's irrelevant, emphasizing what's important'. While seemingly a qualitative goal, artists use known techniques such as relying on source tone over color to indirect into a semantic color temperature model, use brush and tonal "sharpness" to create a center of interest, lost and found edges to move the viewers gaze through the image towards the center of interest as well as other techniques to filter and emphasize. Our work attempts to create a knowledge domain of the portrait painter process and incorporate this knowledge into a multi-space parameterized system that can create an array of NPR painterly rendering output by analyzing the photographic-based input which informs the semantic knowledge rules.

  10. 3D Web-based HMI with WebGL Rendering Performance

    Directory of Open Access Journals (Sweden)

    Muennoi Atitayaporn

    2016-01-01

    Full Text Available An HMI, or Human-Machine Interface, is a software allowing users to communicate with a machine or automation system. It usually serves as a display section in SCADA (Supervisory Control and Data Acquisition system for device monitoring and control. In this papper, a 3D Web-based HMI with WebGL (Web-based Graphics Library rendering performance is presented. The main purpose of this work is to attempt to reduce the limitations of traditional 3D web HMI using the advantage of WebGL. To evaluate the performance, frame rate and frame time metrics were used. The results showed 3D Web-based HMI can maintain the frame rate 60FPS for #cube=0.5K/0.8K, 30FPS for #cube=1.1K/1.6K when it was run on Internet Explorer and Chrome respectively. Moreover, the study found that 3D Web-based HMI using WebGL contains similar frame time in each frame even though the numbers of cubes are up to 5K. This indicated stuttering incurred less in the proposed 3D Web-based HMI compared to the chosen commercial HMI product.

  11. Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

    Science.gov (United States)

    Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

    2014-10-01

    New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. Adaptive statistical iterative reconstruction for volume-rendered computed tomography portovenography. Improvement of image quality

    International Nuclear Information System (INIS)

    Matsuda, Izuru; Hanaoka, Shohei; Akahane, Masaaki

    2010-01-01

    Adaptive statistical iterative reconstruction (ASIR) is a reconstruction technique for computed tomography (CT) that reduces image noise. The purpose of our study was to investigate whether ASIR improves the quality of volume-rendered (VR) CT portovenography. Institutional review board approval, with waived consent, was obtained. A total of 19 patients (12 men, 7 women; mean age 69.0 years; range 25-82 years) suspected of having liver lesions underwent three-phase enhanced CT. VR image sets were prepared with both the conventional method and ASIR. The required time to make VR images was recorded. Two radiologists performed independent qualitative evaluations of the image sets. The Wilcoxon signed-rank test was used for statistical analysis. Contrast-noise ratios (CNRs) of the portal and hepatic vein were also evaluated. Overall image quality was significantly improved by ASIR (P<0.0001 and P=0.0155 for each radiologist). ASIR enhanced CNRs of the portal and hepatic vein significantly (P<0.0001). The time required to create VR images was significantly shorter with ASIR (84.7 vs. 117.1 s; P=0.014). ASIR enhances CNRs and improves image quality in VR CT portovenography. It also shortens the time required to create liver VR CT portovenographs. (author)

  13. High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

    International Nuclear Information System (INIS)

    Miao Yan-Qin; Zhang Ai-Qin; Li Yuan-Hao; Wang Hua; Jia Hu-Sheng; Liu Xu-Guang; Gao Zhi-Xiang; Tsuboi Taijuf

    2015-01-01

    Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7, 7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. (paper)

  14. Heterogeneous Deformable Modeling of Bio-Tissues and Haptic Force Rendering for Bio-Object Modeling

    Science.gov (United States)

    Lin, Shiyong; Lee, Yuan-Shin; Narayan, Roger J.

    This paper presents a novel technique for modeling soft biological tissues as well as the development of an innovative interface for bio-manufacturing and medical applications. Heterogeneous deformable models may be used to represent the actual internal structures of deformable biological objects, which possess multiple components and nonuniform material properties. Both heterogeneous deformable object modeling and accurate haptic rendering can greatly enhance the realism and fidelity of virtual reality environments. In this paper, a tri-ray node snapping algorithm is proposed to generate a volumetric heterogeneous deformable model from a set of object interface surfaces between different materials. A constrained local static integration method is presented for simulating deformation and accurate force feedback based on the material properties of a heterogeneous structure. Biological soft tissue modeling is used as an example to demonstrate the proposed techniques. By integrating the heterogeneous deformable model into a virtual environment, users can both observe different materials inside a deformable object as well as interact with it by touching the deformable object using a haptic device. The presented techniques can be used for surgical simulation, bio-product design, bio-manufacturing, and medical applications.

  15. High-fidelity haptic and visual rendering for patient-specific simulation of temporal bone surgery.

    Science.gov (United States)

    Chan, Sonny; Li, Peter; Locketz, Garrett; Salisbury, Kenneth; Blevins, Nikolas H

    2016-12-01

    Medical imaging techniques provide a wealth of information for surgical preparation, but it is still often the case that surgeons are examining three-dimensional pre-operative image data as a series of two-dimensional images. With recent advances in visual computing and interactive technologies, there is much opportunity to provide surgeons an ability to actively manipulate and interpret digital image data in a surgically meaningful way. This article describes the design and initial evaluation of a virtual surgical environment that supports patient-specific simulation of temporal bone surgery using pre-operative medical image data. Computational methods are presented that enable six degree-of-freedom haptic feedback during manipulation, and that simulate virtual dissection according to the mechanical principles of orthogonal cutting and abrasive wear. A highly efficient direct volume renderer simultaneously provides high-fidelity visual feedback during surgical manipulation of the virtual anatomy. The resulting virtual surgical environment was assessed by evaluating its ability to replicate findings in the operating room, using pre-operative imaging of the same patient. Correspondences between surgical exposure, anatomical features, and the locations of pathology were readily observed when comparing intra-operative video with the simulation, indicating the predictive ability of the virtual surgical environment.

  16. Suppression of SOX18 by siRNA inhibits cell growth and invasion of breast cancer cells.

    Science.gov (United States)

    Zhang, Jianxiang; Ma, Yanmei; Wang, Shoujun; Chen, Fu; Gu, Yuanting

    2016-06-01

    Breast cancer is the most common malignancy in women around the world, and its incidence and mortality rates are still rising. An increasing number of studies have reported that SOX18 plays an important role in various cancers. However, the role of SOX18 in breast cancer remains poorly understood. In this study, we aimed to investigate the biological role and potential molecular mechanism of SOX18 in breast cancer. We found that the mRNA and protein expression levels of SOX18 were prevalently and significantly overexpressed in human breast cancer cell lines. Next, we performed loss-of-function experiments by transfection of two breast cancer cell lines, BT-474 and MCF-7, with SOX18 small interfering RNAs (siRNA). Results showed that SOX18 siRNA transfection significantly suppressed mRNA and protein expression of SOX18 in breast cancer cells. Furthermore, knockdown of SOX18 significantly inhibited cell proliferation and invasion, but promoted apoptosis in breast cancer cells. Importantly, several oncogenic proteins, including the Ras homolog gene family member A (RhoA), platelet-derived growth factor B (PDGFB), Insulin-like growth factor 1 receptor (IGF-1R), and matrix metalloproteinase-7 (MMP-7), were markedly decreased by SOX18 siRNA. Taken together, the results of our study suggest that knockdown of SOX18 inhibits breast cancer cell growth and invasion, possibly by downregulating downstream oncogenic proteins, providing novel insights into the development of breast cancer therapy through targeting of SOX18.

  17. Angiopoietin-2 impairs collateral artery growth associated with the suppression of the infiltration of macrophages in mouse hindlimb ischaemia

    Directory of Open Access Journals (Sweden)

    Xiaoyong Tan

    2016-10-01

    Full Text Available Abstract Background Angiopoietin-2 (Ang-2, a ligand of the Tie-2 receptor, plays an important role in maintaining endothelial cells and in destabilizing blood vessels. Collateral artery growth (arteriogenesis is a key adaptive response to arterial occlusion. It is unknown whether the destabilization of blood vessels by Ang-2 can affect arteriogenesis and modulate mononuclear cell function. This study aimed to investigate the effects of Ang-2 on collateral artery growth. Methods Hindlimb ischaemia model was produced in C57BL/6 mice by femoral artery ligation. Blood flow perfusion was measured using a laser Doppler perfusion imager quantitative RT-PCR analysis was applied to identify the level of angiogenic factors. Results After the induction of hindlimb ischaemia, blood flow recovery was impaired in mice treated with recombinant Ang-2 protein; this was accompanied by a reduction of peri-collateral macrophage infiltration. In addition, quantitative RT-PCR analysis revealed that Ang-2 treatment decreased monocyte chemotactic protein-1 (MCP-1, platelet-derived growth factor-BB (PDGF-BB mRNA levels in ischaemic adductor muscles. Ang-2 can lead to macrophage M1/M2 polarization shift inhibition in the ischaemic muscles. Furthermore, Ang-2 reduced the in vitro inflammatory response in macrophages and vascular cells involved in arteriogenesis. Conclusions Our results demonstrate that Ang-2 is essential for efficient arteriogenesis, which controls macrophage infiltration.

  18. SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

    Science.gov (United States)

    McGlade, C J; Ellis, C; Reedijk, M; Anderson, D; Mbamalu, G; Reith, A D; Panayotou, G; End, P; Bernstein, A; Kazlauskas, A

    1992-01-01

    The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors. Images PMID:1372092

  19. Towards an e-Model for the enhancement of service rendering by SMMEs supporting agencies in South Africa

    CSIR Research Space (South Africa)

    Ngassam, EK

    2009-05-01

    Full Text Available of the existing model to an e-model may lead to an effective and efficient service delivery, which in turn could positively impact on SMMEs operational objectives. The proposed e-model forms the basis for the enhancement of the quality of service rendered...

  20. A two-metric proposal to specify the color-rendering properties of light sources for retail lighting

    Science.gov (United States)

    Freyssinier, Jean Paul; Rea, Mark

    2010-08-01

    Lighting plays an important role in supporting retail operations, from attracting customers, to enabling the evaluation of merchandise, to facilitating the completion of the sale. Lighting also contributes to the identity, comfort, and visual quality of a retail store. With the increasing availability and quality of white LEDs, retail lighting specifiers are now considering LED lighting in stores. The color rendering of light sources is a key factor in supporting retail lighting goals and thus influences a light source's acceptance by users and specifiers. However, there is limited information on what consumers' color preferences are, and metrics used to describe the color properties of light sources often are equivocal and fail to predict preference. The color rendering of light sources is described in the industry solely by the color rendering index (CRI), which is only indirectly related to human perception. CRI is intended to characterize the appearance of objects illuminated by the source and is increasingly being challenged because new sources are being developed with increasingly exotic spectral power distributions. This paper discusses how CRI might be augmented to better use it in support of the design objectives for retail merchandising. The proposed guidelines include the use of gamut area index as a complementary metric to CRI for assuring good color rendering.

  1. Effect of nanostructured lime-based and silica-based products on the consolidation of historical renders

    NARCIS (Netherlands)

    Borsoi, G.; Veiga, R.; Santos Silva, A.

    2013-01-01

    An important operation for the conservation of historical renders is the cohesion restitution of the binderaggregate system, based on the use of materials with consolidating properties. Inorganic consolidants are usually preferred to organic ones due to better compatibility and durability. The aim

  2. Curved reconstructions versus three-dimensional surface rendering in the demonstration of cortical lesions in patients with extratemporal epilepsy

    NARCIS (Netherlands)

    Meiners, LC; Scheffers, JM; De Kort, GAP; Burger, H; Van Huffelen, AC; Van Rijen, PC; Van Veelen, CWM

    RATIONALE AND OBJECTIVES. TO compare the visibility and localization of extratemporal cortical lesions in extratemporal epilepsy by using curved reconstruction (CR) and three-dimensional surface rendering (3D SR) of 3D-acquired MR images and to study the degree of confidence with which localizations

  3. Polyacrylate–water partitioning of biocidal compounds: Enhancing the understanding of biocide partitioning between render and water

    DEFF Research Database (Denmark)

    Bollmann, Ulla E.; Ou, Yi; Mayer, Philipp

    2014-01-01

    -N-octylisothiazolinone). The correlation of the polyacrylate-water partition constants with the octanol-water partition constants is significant, but the polyacrylate-water partition constants were predominantly below octanol-water partition constants (Kow). The comparison with render-water distribution constants showed that estimating...

  4. 31 CFR 500.585 - Payments for services rendered by North Korea to United States aircraft authorized.

    Science.gov (United States)

    2010-07-01

    ... North Korea to United States aircraft authorized. 500.585 Section 500.585 Money and Finance: Treasury... TREASURY FOREIGN ASSETS CONTROL REGULATIONS Licenses, Authorizations and Statements of Licensing Policy § 500.585 Payments for services rendered by North Korea to United States aircraft authorized. Payments...

  5. Wobbled splatting-a fast perspective volume rendering method for simulation of x-ray images from CT

    International Nuclear Information System (INIS)

    Birkfellner, Wolfgang; Seemann, Rudolf; Figl, Michael; Hummel, Johann; Ede, Christopher; Homolka, Peter; Yang Xinhui; Niederer, Peter; Bergmann, Helmar

    2005-01-01

    3D/2D registration, the automatic assignment of a global rigid-body transformation matching the coordinate systems of patient and preoperative volume scan using projection images, is an important topic in image-guided therapy and radiation oncology. A crucial part of most 3D/2D registration algorithms is the fast computation of digitally rendered radiographs (DRRs) to be compared iteratively to radiographs or portal images. Since registration is an iterative process, fast generation of DRRs-which are perspective summed voxel renderings-is desired. In this note, we present a simple and rapid method for generation of DRRs based on splat rendering. As opposed to conventional splatting, antialiasing of the resulting images is not achieved by means of computing a discrete point spread function (a so-called footprint), but by stochastic distortion of either the voxel positions in the volume scan or by the simulation of a focal spot of the x-ray tube with non-zero diameter. Our method generates slightly blurred DRRs suitable for registration purposes at framerates of approximately 10 Hz when rendering volume images with a size of 30 MB. (note)

  6. Dynamic miniature lighting system with low correlated colour temperature and high colour rendering index for museum lighting of fragile artefacts

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Poulsen, Peter Behrensdorff

    2013-01-01

    of historical artefacts in display cases at museums and other exhibitions, which can replace 3-5 Watt incandescent light bulbs with a correlated colour temperature (CCT) from 2000 K to 2400 K. The solution decreases the energy consumption by up to 80 %, while maintaining colour rendering indices (Ra) above 90...

  7. Conservation of the historical render in the Church of Nossa Senhora da Assunção in Elvas

    Directory of Open Access Journals (Sweden)

    Sofia Salema

    2008-01-01

    Full Text Available In this paper we present a practical case of conservation of the historical renders in the pyramidal tower of the Church of Nossa Senhora da Assunção in Elvas (Portugal, carried out by the former IPPAR (Portuguese Institute of Architectonic Heritage, now Regional Direction of Culture of Alentejo. Awareness of the value and of the risks facing these renders points towards the necessity to safeguard their material authenticity. During the works of conservation of the main façade, under the layers of non decorated recovering render, a previous decorated render, simulating stone masonry, with raised joints reproducing stone divisions and the internal structure in solid brick, was discovered. After material and historical analysis we came to the conclusion that it was highly probable that this render was contemporary to the construction of the Church and, as such, it seemed essential to conserve and restore this covering as historical evidence and cultural heritage. Treatment of the pyramidal tower render included removal of the non original recover mortars, survey of ancient materials, execution of technical and decorative scheme, surfaces' cleaning and consolidation of the weaker original old mortars. In order to fill the gaps in the original surface, specific lime mortars, prepared with washed sand and standard grain size, were used. Restoration techniques were used to reconstitute and integrate the lacunas. These actions not only conserved the workmanship, but also reconstructed the decorative structure and a reading clarity, allowing the identification of restoration without the connotation of a mimetic integration. This joint action, only possible with the help of the conservation and restoration team, puts into evidence the possibility of continuous evaluation and learning. It is clear that, in cases where there are unknown, unpredictable factors, due to the specific work and value of the materials, it is possible to change the course

  8. Inhibition of c-Abl kinase activity renders cancer cells highly sensitive to mitoxantrone.

    Directory of Open Access Journals (Sweden)

    Kemal Alpay

    Full Text Available Although c-Abl has increasingly emerged as a key player in the DNA damage response, its role in this context is far from clear. We studied the effect of inhibition of c-Abl kinase activity by imatinib with chemotherapy drugs and found a striking difference in cell survival after combined mitoxantrone (MX and imatinib treatment compared to a panel of other chemotherapy drugs. The combinatory treatment induced apoptosis in HeLa cells and other cancer cell lines but not in primary fibroblasts. The difference in MX and doxorubicin was related to significant augmentation of DNA damage. Transcriptionally active p53 accumulated in cells in which human papillomavirus E6 normally degrades p53. The combination treatment resulted in caspase activation and apoptosis, but this effect did not depend on either p53 or p73 activity. Despite increased p53 activity, the cells arrested in G2 phase became defective in this checkpoint, allowing cell cycle progression. The effect after MX treatment depended partially on c-Abl: Short interfering RNA knockdown of c-Abl rendered HeLa cells less sensitive to MX. The effect of imatinib was decreased by c-Abl siRNA suggesting a role for catalytically inactive c-Abl in the death cascade. These findings indicate that MX has a unique cytotoxic effect when the kinase activity of c-Abl is inhibited. The treatment results in increased DNA damage and c-Abl-dependent apoptosis, which may offer new possibilities for potentiation of cancer chemotherapy.

  9. Automating Geospatial Visualizations with Smart Default Renderers for Data Exploration Web Applications

    Science.gov (United States)

    Ekenes, K.

    2017-12-01

    This presentation will outline the process of creating a web application for exploring large amounts of scientific geospatial data using modern automated cartographic techniques. Traditional cartographic methods, including data classification, may inadvertently hide geospatial and statistical patterns in the underlying data. This presentation demonstrates how to use smart web APIs that quickly analyze the data when it loads, and provides suggestions for the most appropriate visualizations based on the statistics of the data. Since there are just a few ways to visualize any given dataset well, it is imperative to provide smart default color schemes tailored to the dataset as opposed to static defaults. Since many users don't go beyond default values, it is imperative that they are provided with smart default visualizations. Multiple functions for automating visualizations are available in the Smart APIs, along with UI elements allowing users to create more than one visualization for a dataset since there isn't a single best way to visualize a given dataset. Since bivariate and multivariate visualizations are particularly difficult to create effectively, this automated approach removes the guesswork out of the process and provides a number of ways to generate multivariate visualizations for the same variables. This allows the user to choose which visualization is most appropriate for their presentation. The methods used in these APIs and the renderers generated by them are not available elsewhere. The presentation will show how statistics can be used as the basis for automating default visualizations of data along continuous ramps, creating more refined visualizations while revealing the spread and outliers of the data. Adding interactive components to instantaneously alter visualizations allows users to unearth spatial patterns previously unknown among one or more variables. These applications may focus on a single dataset that is frequently updated, or configurable

  10. SparseLeap: Efficient Empty Space Skipping for Large-Scale Volume Rendering

    KAUST Repository

    Hadwiger, Markus

    2017-08-28

    Recent advances in data acquisition produce volume data of very high resolution and large size, such as terabyte-sized microscopy volumes. These data often contain many fine and intricate structures, which pose huge challenges for volume rendering, and make it particularly important to efficiently skip empty space. This paper addresses two major challenges: (1) The complexity of large volumes containing fine structures often leads to highly fragmented space subdivisions that make empty regions hard to skip efficiently. (2) The classification of space into empty and non-empty regions changes frequently, because the user or the evaluation of an interactive query activate a different set of objects, which makes it unfeasible to pre-compute a well-adapted space subdivision. We describe the novel SparseLeap method for efficient empty space skipping in very large volumes, even around fine structures. The main performance characteristic of SparseLeap is that it moves the major cost of empty space skipping out of the ray-casting stage. We achieve this via a hybrid strategy that balances the computational load between determining empty ray segments in a rasterization (object-order) stage, and sampling non-empty volume data in the ray-casting (image-order) stage. Before ray-casting, we exploit the fast hardware rasterization of GPUs to create a ray segment list for each pixel, which identifies non-empty regions along the ray. The ray-casting stage then leaps over empty space without hierarchy traversal. Ray segment lists are created by rasterizing a set of fine-grained, view-independent bounding boxes. Frame coherence is exploited by re-using the same bounding boxes unless the set of active objects changes. We show that SparseLeap scales better to large, sparse data than standard octree empty space skipping.

  11. SparseLeap: Efficient Empty Space Skipping for Large-Scale Volume Rendering

    KAUST Repository

    Hadwiger, Markus; Al-Awami, Ali K.; Beyer, Johanna; Agus, Marco; Pfister, Hanspeter

    2017-01-01

    Recent advances in data acquisition produce volume data of very high resolution and large size, such as terabyte-sized microscopy volumes. These data often contain many fine and intricate structures, which pose huge challenges for volume rendering, and make it particularly important to efficiently skip empty space. This paper addresses two major challenges: (1) The complexity of large volumes containing fine structures often leads to highly fragmented space subdivisions that make empty regions hard to skip efficiently. (2) The classification of space into empty and non-empty regions changes frequently, because the user or the evaluation of an interactive query activate a different set of objects, which makes it unfeasible to pre-compute a well-adapted space subdivision. We describe the novel SparseLeap method for efficient empty space skipping in very large volumes, even around fine structures. The main performance characteristic of SparseLeap is that it moves the major cost of empty space skipping out of the ray-casting stage. We achieve this via a hybrid strategy that balances the computational load between determining empty ray segments in a rasterization (object-order) stage, and sampling non-empty volume data in the ray-casting (image-order) stage. Before ray-casting, we exploit the fast hardware rasterization of GPUs to create a ray segment list for each pixel, which identifies non-empty regions along the ray. The ray-casting stage then leaps over empty space without hierarchy traversal. Ray segment lists are created by rasterizing a set of fine-grained, view-independent bounding boxes. Frame coherence is exploited by re-using the same bounding boxes unless the set of active objects changes. We show that SparseLeap scales better to large, sparse data than standard octree empty space skipping.

  12. Clinical Application of an Open-Source 3D Volume Rendering Software to Neurosurgical Approaches.

    Science.gov (United States)

    Fernandes de Oliveira Santos, Bruno; Silva da Costa, Marcos Devanir; Centeno, Ricardo Silva; Cavalheiro, Sergio; Antônio de Paiva Neto, Manoel; Lawton, Michael T; Chaddad-Neto, Feres

    2018-02-01

    Preoperative recognition of the anatomic individualities of each patient can help to achieve more precise and less invasive approaches. It also may help to anticipate potential complications and intraoperative difficulties. Here we describe the use, accuracy, and precision of a free tool for planning microsurgical approaches using 3-dimensional (3D) reconstructions from magnetic resonance imaging (MRI). We used the 3D volume rendering tool of a free open-source software program for 3D reconstruction of images of surgical sites obtained by MRI volumetric acquisition. We recorded anatomic reference points, such as the sulcus and gyrus, and vascularization patterns for intraoperative localization of lesions. Lesion locations were confirmed during surgery by intraoperative ultrasound and/or electrocorticography and later by postoperative MRI. Between August 2015 and September 2016, a total of 23 surgeries were performed using this technique for 9 low-grade gliomas, 7 high-grade gliomas, 4 cortical dysplasias, and 3 arteriovenous malformations. The technique helped delineate lesions with an overall accuracy of 2.6 ± 1.0 mm. 3D reconstructions were successfully performed in all patients, and images showed sulcus, gyrus, and venous patterns corresponding to the intraoperative images. All lesion areas were confirmed both intraoperatively and at the postoperative evaluation. With the technique described herein, it was possible to successfully perform 3D reconstruction of the cortical surface. This reconstruction tool may serve as an adjunct to neuronavigation systems or may be used alone when such a system is unavailable. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Technical Note: A 3-D rendering algorithm for electromechanical wave imaging of a beating heart.

    Science.gov (United States)

    Nauleau, Pierre; Melki, Lea; Wan, Elaine; Konofagou, Elisa

    2017-09-01

    Arrhythmias can be treated by ablating the heart tissue in the regions of abnormal contraction. The current clinical standard provides electroanatomic 3-D maps to visualize the electrical activation and locate the arrhythmogenic sources. However, the procedure is time-consuming and invasive. Electromechanical wave imaging is an ultrasound-based noninvasive technique that can provide 2-D maps of the electromechanical activation of the heart. In order to fully visualize the complex 3-D pattern of activation, several 2-D views are acquired and processed separately. They are then manually registered with a 3-D rendering software to generate a pseudo-3-D map. However, this last step is operator-dependent and time-consuming. This paper presents a method to generate a full 3-D map of the electromechanical activation using multiple 2-D images. Two canine models were considered to illustrate the method: one in normal sinus rhythm and one paced from the lateral region of the heart. Four standard echographic views of each canine heart were acquired. Electromechanical wave imaging was applied to generate four 2-D activation maps of the left ventricle. The radial positions and activation timings of the walls were automatically extracted from those maps. In each slice, from apex to base, these values were interpolated around the circumference to generate a full 3-D map. In both cases, a 3-D activation map and a cine-loop of the propagation of the electromechanical wave were automatically generated. The 3-D map showing the electromechanical activation timings overlaid on realistic anatomy assists with the visualization of the sources of earlier activation (which are potential arrhythmogenic sources). The earliest sources of activation corresponded to the expected ones: septum for the normal rhythm and lateral for the pacing case. The proposed technique provides, automatically, a 3-D electromechanical activation map with a realistic anatomy. This represents a step towards a

  14. High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

    Science.gov (United States)

    Miao, Yan-Qin; Gao, Zhi-Xiang; Zhang, Ai-Qin; Li, Yuan-Hao; Wang, Hua; Jia, Hu-Sheng; Liu, Xu-Guang; Tsuboi, Taijuf

    2015-05-01

    Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. Project supported by the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-13-0927), the International Science & Technology Cooperation Program of China (Grant No. 2012DFR50460), the National Natural Science Foundation of China (Grant Nos. 21101111 and 61274056), and the Shanxi Provincial Key Innovative Research Team in Science and Technology, China (Grant No. 2012041011).

  15. Bleed-through correction for rendering and correlation analysis in multi-colour localization microscopy

    International Nuclear Information System (INIS)

    Kim, Dahan; Curthoys, Nikki M; Parent, Matthew T; Hess, Samuel T

    2013-01-01

    Multi-colour localization microscopy has enabled sub-diffraction studies of colocalization between multiple biological species and quantification of their correlation at length scales previously inaccessible with conventional fluorescence microscopy. However, bleed-through, or misidentification of probe species, creates false colocalization and artificially increases certain types of correlation between two imaged species, affecting the reliability of information provided by colocalization and quantified correlation. Despite the potential risk of these artefacts of bleed-through, neither the effect of bleed-through on correlation nor methods for its correction in correlation analyses have been systematically studied at typical rates of bleed-through reported to affect multi-colour imaging. Here, we present a reliable method of bleed-through correction applicable to image rendering and correlation analysis of multi-colour localization microscopy. Application of our bleed-through correction shows that our method accurately corrects the artificial increase in both types of correlation studied (Pearson coefficient and pair correlation), at all rates of bleed-through tested, in all types of correlation examined. In particular, anti-correlation could not be quantified without our bleed-through correction, even at rates of bleed-through as low as 2%. While it is demonstrated with dichroic-based multi-colour FPALM here, our presented method of bleed-through correction can be applied to all types of localization microscopy (PALM, STORM, dSTORM, GSDIM, etc), including both simultaneous and sequential multi-colour modalities, provided the rate of bleed-through can be reliably determined. (special issue article)

  16. Minimally invasive esthetic ridge preservation with growth-factor enhanced bone matrix.

    Science.gov (United States)

    Nevins, Marc L; Said, Sherif

    2017-12-28

    Extraction socket preservation procedures are critical to successful esthetic implant therapy. Conventional surgical approaches are technique sensitive and often result in alteration of the soft tissue architecture, which then requires additional corrective surgical procedures. This case series report presents the ability of flapless surgical techniques combined with a growth factor-enhanced bone matrix to provide esthetic ridge preservation at the time of extraction for compromised sockets. When considering esthetic dental implant therapy, preservation, or further enhancement of the available tissue support at the time of tooth extraction may provide an improved esthetic outcome with reduced postoperative sequelae and decreased treatment duration. Advances in minimally invasive surgical techniques combined with recombinant growth factor technology offer an alternative for bone reconstruction while maintaining the gingival architecture for enhanced esthetic outcome. The combination of freeze-dried bone allograft (FDBA) and rhPDGF-BB (platelet-derived growth factor-BB) provides a growth-factor enhanced matrix to induce bone and soft tissue healing. The use of a growth-factor enhanced matrix is an option for minimally invasive ridge preservation procedures for sites with advanced bone loss. Further studies including randomized clinical trials are needed to better understand the extent and limits of these procedures. The use of minimally invasive techniques with growth factors for esthetic ridge preservation reduces patient morbidity associated with more invasive approaches and increases the predictability for enhanced patient outcomes. By reducing the need for autogenous bone grafts the use of this technology is favorable for patient acceptance and ease of treatment process for esthetic dental implant therapy. © 2017 Wiley Periodicals, Inc.

  17. Geometrical versus Random β-TCP Scaffolds: Exploring the Effects on Schwann Cell Growth and Behavior.

    Directory of Open Access Journals (Sweden)

    Lauren Sweet

    Full Text Available Numerous studies have demonstrated that Schwann cells (SCs play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP scaffolds arranged in 3D printed-lattice (P-β-TCP and randomly-porous, template-casted (N-β-TCP structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf, neutrophin-3 (nt-3, platelet-derived growth factor (pdgf-bb, and vascular endothelial growth factor (vegf-a were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts.

  18. The diminished expression of proangiogenic growth factors and their receptors in gastric ulcers of cirrhotic patients.

    Science.gov (United States)

    Luo, Jiing-Chyuan; Peng, Yen-Ling; Hou, Ming-Chih; Huang, Kuang-Wei; Huang, Hui-Chun; Wang, Ying-Wen; Lin, Han-Chieh; Lee, Fa-Yauh; Lu, Ching-Liang

    2013-01-01

    The pathogenesis of the higher occurrence of peptic ulcer disease in cirrhotic patients is complex. Platelets can stimulate angiogenesis and promote gastric ulcer healing. We compared the expressions of proangiogenic growth factors and their receptors in the gastric ulcer margin between cirrhotic patients with thrombocytopenia and those of non-cirrhotic patients to elucidate possible mechanisms. Eligible cirrhotic patients (n = 55) and non-cirrhotic patients (n = 55) who had gastric ulcers were enrolled. Mucosa from the gastric ulcer margin and non-ulcer areas were sampled and the mRNA expressions of the proangiogenic growth factors (vascular endothelial growth factor [VEGF], platelet derived growth factor [PDGF], basic fibroblast growth factor [bFGF]) and their receptors (VEGFR1, VEGFR2, PDGFRA, PDGFRB, FGFR1, FGFR2) were measured and compared. Platelet count and the expressions of these growth factors and their receptors were correlated with each other. The two groups were comparable in terms of gender, ulcer size and infection rate of Helicobacter pylori. However, the cirrhotic group were younger in age, had a lower platelet count than those in the non-cirrhotic group (pexpressions of PDGFB, VEGFR2, FGFR1, and FGFR2 in gastric ulcer margin when compared with those of the non-cirrhotic patients (pexpressions of PDGFB and VEGFR2, FGFR1, and FGFR2 were well correlated with the degree of thrombocytopenia in these cirrhotic patients (ρ>0.5, pimplied that diminished activity of proangiogenic factors and their receptors may contribute to the pathogenesis of gastric ulcers in cirrhotic patients.

  19. Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

    Science.gov (United States)

    Shah, Nisarg J.; Hyder, Md. Nasim; Quadir, Mohiuddin A.; Dorval Courchesne, Noémie-Manuelle; Seeherman, Howard J.; Nevins, Myron; Spector, Myron; Hammond, Paula T.

    2014-01-01

    Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration. PMID:25136093

  20. New impressive capabilities of SE-workbench for EO/IR real-time rendering of animated scenarios including flares

    Science.gov (United States)

    Le Goff, Alain; Cathala, Thierry; Latger, Jean

    2015-10-01

    To provide technical assessments of EO/IR flares and self-protection systems for aircraft, DGA Information superiority resorts to synthetic image generation to model the operational battlefield of an aircraft, as viewed by EO/IR threats. For this purpose, it completed the SE-Workbench suite from OKTAL-SE with functionalities to predict a realistic aircraft IR signature and is yet integrating the real-time EO/IR rendering engine of SE-Workbench called SE-FAST-IR. This engine is a set of physics-based software and libraries that allows preparing and visualizing a 3D scene for the EO/IR domain. It takes advantage of recent advances in GPU computing techniques. The recent past evolutions that have been performed concern mainly the realistic and physical rendering of reflections, the rendering of both radiative and thermal shadows, the use of procedural techniques for the managing and the rendering of very large terrains, the implementation of Image- Based Rendering for dynamic interpolation of plume static signatures and lastly for aircraft the dynamic interpolation of thermal states. The next step is the representation of the spectral, directional, spatial and temporal signature of flares by Lacroix Defense using OKTAL-SE technology. This representation is prepared from experimental data acquired during windblast tests and high speed track tests. It is based on particle system mechanisms to model the different components of a flare. The validation of a flare model will comprise a simulation of real trials and a comparison of simulation outputs to experimental results concerning the flare signature and above all the behavior of the stimulated threat.