Antimicrobial medium- and long-chain free fatty acids prevent PrfA-dependent activation of virulence genes in Listeria monocytogenes

DEFF Research Database (Denmark)

Sternkopf Lillebæk, Eva Maria; Lambert Nielsen, Stine; Scheel Thomasen, Rikke

2017-01-01

of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. PrfA-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection. In contrast, PrfA does not play a significant role in regulation of virulence gene expression...... antimicrobial free fatty acids act to downregulate transcription of PrfA-activated virulence genes. Interestingly, the inhibitory effect is also evident in cells encoding a constitutively active variant of PrfA. Collectively, our data suggest that antimicrobial medium- and long-chain free fatty acids may act...... as signals to prevent PrfA-mediated activation of virulence genes in environments where PrfA activation is not required, such as in food and the gastrointestinal tract....

A case report of novel mutation in PRF1 gene, which causes familial autosomal recessive hemophagocytic lymphohistiocytosis.

Science.gov (United States)

Bordbar, Mohammad Reza; Modarresi, Farzaneh; Farazi Fard, Mohammad Ali; Dastsooz, Hassan; Shakib Azad, Nader; Faghihi, Mohammad Ali

2017-05-03

Hemophagocytic Lymphohistiocytosis (HLH) is a life-threatening immunodeficiency and multi-organ disease that affects people of all ages and ethnic groups. Common symptoms and signs of this disease are high fever, hepatosplenomegaly, and cytopenias. Familial form of HLH disease, which is an autosomal recessive hematological disorder is due to disease-causing mutations in several genes essential for NK and T-cell granule-mediated cytotoxic function. For an effective cytotoxic response from cytotoxic T lymphocyte or NK cell encountering an infected cell or tumor cell, different processes are required, including trafficking, docking, priming, membrane fusion, and entry of cytotoxic granules into the target cell leading to apoptosis. Therefore, genes involved in these steps play important roles in the pathogenesis of HLH disease which include PRF1, UNC13D (MUNC13-4), STX11, and STXBP2 (MUNC18-2). Here, we report a novel missense mutation in an 8-year-old boy suffered from hepatosplenomegaly, hepatitis, epilepsy and pancytopenia. The patient was born to a first-cousin parents with no previous documented disease in his parents. To identify mutated gene in the proband, Whole Exome Sequencing (WES) utilizing next generation sequencing was used on an Illumina HiSeq 2000 platform on DNA sample from the patient. Results showed a novel deleterious homozygous missense mutation in PRF1 gene (NM_001083116: exon3: c. 1120 T > G, p.W374G) in the patient and then using Sanger sequencing it was confirmed in the proband and his parents. Since his parents were heterozygous for the identified mutation, autosomal recessive pattern of inheritance was confirmed in the family. Our study identified a rare new pathogenic missense mutation in PRF1 gene in patient with HLH disease and it is the first report of mutation in PRF1 in Iranian patients with this disease.

Antimicrobial medium- and long-chain free fatty acids prevent PrfA-dependent activation of virulence genes in Listeria monocytogenes.

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Sternkopf Lillebæk, Eva Maria; Lambert Nielsen, Stine; Scheel Thomasen, Rikke; Færgeman, Nils J; Kallipolitis, Birgitte H

The foodborne pathogen Listeria monocytogenes is the causative agent of the invasive disease listeriosis. Infection by L. monocytogenes involves bacterial crossing of the intestinal barrier and intracellular replication in a variety of host cells. The PrfA protein is the master regulator of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. PrfA-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection. In contrast, PrfA does not play a significant role in regulation of virulence gene expression in the intestinal environment. In the gastrointestinal phase of infection, the bacterium encounters a variety of antimicrobial agents, including medium- and long-chain free fatty acids that are commonly found in our diet and as active components of bile. Here we show that subinhibitory concentrations of specific antimicrobial free fatty acids act to downregulate transcription of PrfA-activated virulence genes. Interestingly, the inhibitory effect is also evident in cells encoding a constitutively active variant of PrfA. Collectively, our data suggest that antimicrobial medium- and long-chain free fatty acids may act as signals to prevent PrfA-mediated activation of virulence genes in environments where PrfA activation is not required, such as in food and the gastrointestinal tract. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Use of Leukocyte Platelet (L-PRF Rich Fibrin in Diabetic Foot Ulcer with Osteomyelitis (Three Clinical Cases Report

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Alessandro Crisci

2018-04-01

Full Text Available In this study, the use of fibrin rich in leukocytes and platelets (L-PRF was explored to heal osteomyelitis ulcers in a diabetic foot. The goal was to standardize the utilization of L-PRF in patients with osteomyelitis to direct it for healing. L-PRF was obtained autologously from the peripheral blood of the diabetic patients (n = 3 having osteomyelitis and skin lesions for at least six months. The L-PRF and supernatant serum were inserted into the skin lesion to the bone after a surgical debridement. The evolution of lesions over time was analyzed. All three patients showed positivity to the Probe-to-Bone test and Nuclear Magnetic Resonance detected cortico-periosteal thickening and/or outbreaks of spongy cortical osteolysis in adjacency of the ulcer. The infections were caused by Cocci Gram-positive bacteria, such as S. Aureus, S. β-hemolytic, S. Viridans and Bacilli; and Gram-negative such as Pseudomonas, Proteus, Enterobacter; and yeast, Candida. The blood count did not show any significant alterations. To date, all three patients have healed skin lesions (in a patient for about two years with no evidence of infection. These preliminary results showed that L-PRF membranes could be a new method of therapy in such problematic diseases. Overall, the L-PRF treatment in osteomyelitis of a diabetic foot seems to be easy and cost-effective by regenerative therapy of chronic skin lesions. In addition, it will improve our understanding of wound healing.

Breakdown of Preservative Fluid MIL-PRF-46170 in Aircraft Hydraulic Systems

National Research Council Canada - National Science Library

Moorman, Jeffrey

2001-01-01

.... Additional information obtained from outside sources is also summarized for background. Laboratory pump testing showed rapid filter dogging with small amounts of preservative fluid (MU-PRF-46l70) in the system...

Evaluation of the performance of quantitative detection of the Listeria monocytogenes prfA locus with droplet digital PCR.

Science.gov (United States)

Witte, Anna Kristina; Fister, Susanne; Mester, Patrick; Schoder, Dagmar; Rossmanith, Peter

2016-11-01

Fast and reliable pathogen detection is an important issue for human health. Since conventional microbiological methods are rather slow, there is growing interest in detection and quantification using molecular methods. The droplet digital polymerase chain reaction (ddPCR) is a relatively new PCR method for absolute and accurate quantification without external standards. Using the Listeria monocytogenes specific prfA assay, we focused on the questions of whether the assay was directly transferable to ddPCR and whether ddPCR was suitable for samples derived from heterogeneous matrices, such as foodstuffs that often included inhibitors and a non-target bacterial background flora. Although the prfA assay showed suboptimal cluster formation, use of ddPCR for quantification of L. monocytogenes from pure bacterial cultures, artificially contaminated cheese, and naturally contaminated foodstuff was satisfactory over a relatively broad dynamic range. Moreover, results demonstrated the outstanding detection limit of one copy. However, while poorer DNA quality, such as resulting from longer storage, can impair ddPCR, internal amplification control (IAC) of prfA by ddPCR, that is integrated in the genome of L. monocytogenes ΔprfA, showed even slightly better quantification over a broader dynamic range. Graphical Abstract Evaluating the absolute quantification potential of ddPCR targeting Listeria monocytogenes prfA.

The metabolic regulator CodY links L. monocytogenes metabolism to virulence by directly activating the virulence regulatory gene, prfA

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Lobel, Lior; Sigal, Nadejda; Borovok, Ilya; Belitsky, Boris R.; Sonenshein, Abraham L.; Herskovits, Anat A.

2015-01-01

Summary Metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. Previously, we reported that the intracellular bacterial pathogen Listeria monocytogenes responds to low availability of branched-chain amino acids (BCAA) within mammalian cells by up-regulating both BCAA biosynthesis and virulence genes. The induction of virulence genes required the BCAA-responsive transcription regulator, CodY, but the molecular mechanism governing this mode of regulation was unclear. In this report, we demonstrate that CodY directly binds the coding sequence of the L. monocytogenes master virulence activator gene, prfA, 15 nt downstream of its start codon, and that this binding results in up-regulation of prfA transcription specifically under low concentrations of BCAA. Mutating this site abolished CodY binding and reduced prfA transcription in macrophages, and attenuated bacterial virulence in mice. Notably, the mutated binding site did not alter prfA transcription or PrfA activity under other conditions that are known to activate PrfA, such as during growth in the presence of glucose-1-phosphate. This study highlights the tight crosstalk between L. monocytogenes metabolism and virulence' while revealing novel features of CodY-mediated regulation. PMID:25430920

GrayQb^TM Single-Faced Version 2 (SF2) Hanford Plutonium Reclamation Facility (PRF) deployment report

Energy Technology Data Exchange (ETDEWEB)

Plummer, J. R. [Savannah River Site (SRS), Aiken, SC (United States); Immel, D. M. [Savannah River Site (SRS), Aiken, SC (United States); Serrato, M. G. [Savannah River Site (SRS), Aiken, SC (United States); Dalmaso, M. J. [Savannah River Site (SRS), Aiken, SC (United States); Shull, D. J. [Savannah River Site (SRS), Aiken, SC (United States)

2015-11-18

The Savannah River National Laboratory (SRNL) in partnership with CH2M Plateau Remediation Company (CHPRC) deployed the GrayQb^TM SF2 radiation imaging device at the Hanford Plutonium Reclamation Facility (PRF) to assist in the radiological characterization of the canyon. The deployment goal was to locate radiological contamination hot spots in the PRF canyon, where pencil tanks were removed and decontamination/debris removal operations are on-going, to support the CHPRC facility decontamination and decommissioning (D&D) effort. The PRF canyon D&D effort supports completion of the CHPRC Plutonium Finishing Plant Decommissioning Project. The GrayQb^TM SF2 (Single Faced Version 2) is a non-destructive examination device developed by SRNL to generate radiation contour maps showing source locations and relative radiological levels present in the area under examination. The Hanford PRF GrayQbTM Deployment was sponsored by CH2M Plateau Remediation Company (CHPRC) through the DOE Richland Operations Office, Inter-Entity Work Order (IEWO), DOE-RL IEWO- M0SR900210.

The impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors, and fibrin architecture of a leukocyte- and platelet-rich fibrin (L-PRF) clot and membrane.

Science.gov (United States)

Dohan Ehrenfest, David M; Pinto, Nelson R; Pereda, Andrea; Jiménez, Paula; Corso, Marco Del; Kang, Byung-Soo; Nally, Mauricio; Lanata, Nicole; Wang, Hom-Lay; Quirynen, Marc

2018-03-01

L-PRF (leukocyte- and platelet-rich fibrin) is one of the four families of platelet concentrates for surgical use and is widely used in oral and maxillofacial regenerative therapies. The first objective of this article was to evaluate the mechanical vibrations appearing during centrifugation in four models of commercially available table-top centrifuges used to produce L-PRF and the impact of the centrifuge characteristics on the cell and fibrin architecture of a L-PRF clot and membrane. The second objective of this article was to evaluate how changing some parameters of the L-PRF protocol may influence its biological signature, independently from the characteristics of the centrifuge. In the first part, four different commercially available centrifuges were used to produce L-PRF, following the original L-PRF production method (glass-coated plastic tubes, 400 g force, 12 minutes). The tested systems were the original L-PRF centrifuge (Intra-Spin, Intra-Lock, the only CE and FDA cleared system for the preparation of L-PRF) and three other laboratory centrifuges (not CE/FDA cleared for L-PRF): A-PRF 12 (Advanced PRF, Process), LW-UPD8 (LW Scientific) and Salvin 1310 (Salvin Dental). Each centrifuge was opened for inspection, two accelerometers were installed (one radial, one vertical), and data were collected with a spectrum analyzer in two configurations (full-load or half load). All clots and membranes were collected into a sterile surgical box (Xpression kit, Intra-Lock). The exact macroscopic (weights, sizes) and microscopic (photonic and scanning electron microscopy SEM) characteristics of the L-PRF produced with these four different machines were evaluated. In the second part, venous blood was taken in two groups, respectively, Intra-Spin 9 ml glass-coated plastic tubes (Intra-Lock) and A-PRF 10 ml glass tubes (Process). Tubes were immediately centrifuged at 2700 rpm (around 400 g) during 12 minutes to produce L-PRF or at 1500 rpm during 14 minutes to produce A-PRF

Endurance Pump Tests With Fresh and Purified MIL-PRF-83282 Hydraulic Fluid

National Research Council Canada - National Science Library

Sharma, Shashi

1999-01-01

.... Two endurance pump tests were conducted with F-16 aircraft hydraulic pumps, using both fresh and purified MIL-PRF-83282 hydraulic fluid, to determine if fluid purification had any adverse effect on pump life...

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.

A numerical study of HCCI combustion of PRF mixtures compared with PCCI experiments

Energy Technology Data Exchange (ETDEWEB)

Van Wijngaarden, B.

2008-09-15

For automotive applications engines that produce less soot and NOx are desired. For that reason the Homogeneous Charge Compression Ignition (HCCI) principle is investigated all over the world, including the technical universities of Berlin (TUB) and Eindhoven. HCCI combines a homogeneous charge, as in an Otto engine with the autoignition principle of a Diesel engine. Auto-ignition and almost instantaneous combustion of a homogeneous charge leads to almost zero soot emissions, lower temperatures and thereby much lower NOx emissions. Auto-ignition timing however, depends on the fuel and its chemistry, which is very sensitive to the applied conditions, being pressure, temperature, equivalence ratio ({phi}), dilution with EGR and engine speed. To study this systematically a 0D model with PRF fuels is used (Primary Reference Fuels are n-heptane, iso-octane and mixtures). A 0D model is chosen because it excludes complex fluid dynamics and thereby allows the use of detailed combustion mechanisms, describing the (PRF) chemistry. Furthermore the model has a multi zone possibility to evaluate in-homogeneities of the charge. PRF fuels are used because n-heptane (CN=55) auto-ignites like a diesel and iso-octane (ON=100) approaches gasoline. For the PRF chemistry three combustion mechanisms were selected, of which two were validated showing a great difference in predicted ignition delay and sensitivity to changes. Furthermore the model was validated with a PCCI (Premixed Charge Compression Ignition) experiment. Extensive comparisons with PCCI experiments from the TUB showed that when the moment of injection was used to launch the chemistry in the model, only the Soyhan mechanism predicted the ignition close to the experimental ignition moment. Furthermore a 7 zone model was able to approach the experimental CO and NOX emissions. Finally none of the mechanisms was able to predict a pressure profile similar to the experiments. More zones and or a better mechanism could improve

Domestication-driven Gossypium profilin 1 (GhPRF1) gene transduces early flowering phenotype in tobacco by spatial alteration of apical/floral-meristem related gene expression.

Science.gov (United States)

Pandey, Dhananjay K; Chaudhary, Bhupendra

2016-05-13

Plant profilin genes encode core cell-wall structural proteins and are evidenced for their up-regulation under cotton domestication. Notwithstanding striking discoveries in the genetics of cell-wall organization in plants, little is explicit about the manner in which profilin-mediated molecular interplay and corresponding networks are altered, especially during cellular signalling of apical meristem determinacy and flower development. Here we show that the ectopic expression of GhPRF1 gene in tobacco resulted in the hyperactivation of apical meristem and early flowering phenotype with increased flower number in comparison to the control plants. Spatial expression alteration in CLV1, a key meristem-determinacy gene, is induced by the GhPRF1 overexpression in a WUS-dependent manner and mediates cell signalling to promote flowering. But no such expression alterations are recorded in the GhPRF1-RNAi lines. The GhPRF1 transduces key positive flowering regulator AP1 gene via coordinated expression of FT4, SOC1, FLC1 and FT1 genes involved in the apical-to-floral meristem signalling cascade which is consistent with our in silico profilin interaction data. Remarkably, these positive and negative flowering regulators are spatially controlled by the Actin-Related Protein (ARP) genes, specifically ARP4 and ARP6 in proximate association with profilins. This study provides a novel and systematic link between GhPRF1 gene expression and the flower primordium initiation via up-regulation of the ARP genes, and an insight into the functional characterization of GhPRF1 gene acting upstream to the flowering mechanism. Also, the transgenic plants expressing GhPRF1 gene show an increase in the plant height, internode length, leaf size and plant vigor. Overexpression of GhPRF1 gene induced early and increased flowering in tobacco with enhanced plant vigor. During apical meristem determinacy and flower development, the GhPRF1 gene directly influences key flowering regulators through ARP

Platelet Rich Fibrin (P.R.F.) in Reconstructive Surgery of Atrophied Maxillary Bones: Clinical and Histological Evaluations

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Tatullo, Marco; Marrelli, Massimo; Cassetta, Michele; Pacifici, Andrea; Stefanelli, Luigi Vito; Scacco, Salvatore; Dipalma, Gianna; Pacifici, Luciano; Inchingolo, Francesco

2012-01-01

Introduction. Maxillary bone losses often require additional regenerative procedures: as a supplement to the procedures of tissue regeneration, a platelet concentrate called PRF (Platelet Rich Fibrin) was tested for the first time in France by Dr. Choukroun. Aim of the present study is to investigate, clinically and histologically, the potential use of PRF, associated with deproteinized bovine bone (Bio-Oss), as grafting materials in pre-implantology sinus grafting of severe maxillary atrophy, in comparison with a control group, in which only deproteinized bovine bone (Bio-Oss) was used as reconstructive material. Materials and Methods. 60 patients were recruited using the cluster-sampling method; inclusion criteria were maxillary atrophy with residual ridge piezosurgery in order to reduce trauma and to optimize the design of the operculum on the cortical bone. The reopening of the surgical area was scheduled at 3 different times. Results. 72 sinus lifts were performed with subsequent implants insertions. We want to underline how the histological results proved that the samples collected after 106 days (Early protocol) with the adding of PRF were constituted by lamellar bone tissue with an interposed stroma that appeared relaxed and richly vascularized. Conclusions. The use of PRF and piezosurgery reduced the healing time, compared to the 150 days described in literature, favoring optimal bone regeneration. At 106 days, it is already possible to achieve good primary stability of endosseous implants, though lacking of functional loading. PMID:23155361

Leucocyte- and platelet-rich fibrin (L-PRF) as a regenerative medicine strategy for the treatment of refractory leg ulcers: a prospective cohort study.

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Pinto, Nelson R; Ubilla, Matias; Zamora, Yelka; Del Rio, Verónica; Dohan Ehrenfest, David M; Quirynen, Marc

2017-07-20

Chronic wounds (VLU: venous leg ulcer, DFU: diabetic foot ulcer, PU: pressure ulcer, or complex wounds) affect a significant proportion of the population. Despite appropriate standard wound care, such ulcers unfortunately may remain open for months or even years. The use of leukocyte- and platelet-rich fibrin (L-PRF) to cure skin ulcers is a simple and inexpensive method, widely used in some countries but unknown or neglected in most others. This auto-controlled prospective cohort study explored and quantified accurately for the first time the adjunctive benefits of topical applications of L-PRF in the management of such refractory ulcers in a diverse group of patients. Forty-four consecutive patients with VLUs (n = 28, 32 wounds: 17 ≤ 10 cm 2 and 15 > 10 cm 2 ), DPUs (n = 9, 10 wounds), PUs (n = 5), or complex wounds (n = 2), all refractory to standard treatment for ≥3 months, received a weekly application of L-PRF membranes. L-PRF was prepared following the original L-PRF method developed more than 15 years ago (400g, 12 minutes) using the Intra-Spin L-PRF centrifuge/system and the XPression box kit (Intra-Lock, Boca Raton, FL, USA; the only CE/FDA cleared system for the preparation of L-PRF). Changes in wound area were recorded longitudinally via digital planimetry. Adverse events and pain levels were also registered. All wounds showed significant improvements after the L-PRF therapy. All VLUs ≤ 10 cm 2 , all DFUs, as well as the two complex wounds showed full closure within a 3-month period. All wounds of patients with VLUs > 10 cm 2 who continued therapy (10 wounds) could be closed, whereas in the five patients who discontinued therapy improvement of wound size was observed. Two out of the five PUs were closed, with improvement in the remaining three patients who again interrupted therapy (surface evolution from 7.35 ± 4.31 cm 2 to 5.78 ± 3.81 cm 2 ). No adverse events were observed. A topical application of L-PRF on

Leukocyte- and platelet-rich fibrin (L-PRF) for long-term delivery of growth factor in rotator cuff repair: review, preliminary results and future directions.

Science.gov (United States)

Zumstein, Matthias A; Berger, Simon; Schober, Martin; Boileau, Pascal; Nyffeler, Richard W; Horn, Michael; Dahinden, Clemens A

2012-06-01

Surgical repair of the rotator cuff repair is one of the most common procedures in orthopedic surgery. Despite it being the focus of much research, the physiological tendon-bone insertion is not recreated following repair and there is an anatomic non-healing rate of up to 94%. During the healing phase, several growth factors are upregulated that induce cellular proliferation and matrix deposition. Subsequently, this provisional matrix is replaced by the definitive matrix. Leukocyte- and platelet-rich fibrin (L-PRF) contain growth factors and has a stable dense fibrin matrix. Therefore, use of LPRF in rotator cuff repair is theoretically attractive. The aim of the present study was to determine 1) the optimal protocol to achieve the highest leukocyte content; 2) whether L-PRF releases growth factors in a sustained manner over 28 days; 3) whether standard/gelatinous or dry/compressed matrix preparation methods result in higher growth factor concentrations. 1) The standard L-PRF centrifugation protocol with 400 x g showed the highest concentration of platelets and leukocytes. 2) The L-PRF clots cultured in medium showed a continuous slow release with an increase in the absolute release of growth factors TGF-β1, VEGF and MPO in the first 7 days, and for IGF1, PDGF-AB and platelet activity (PF4=CXCL4) in the first 8 hours, followed by a decrease to close to zero at 28 days. Significantly higher levels of growth factor were expressed relative to the control values of normal blood at each culture time point. 3) Except for MPO and the TGFβ-1, there was always a tendency towards higher release of growth factors (i.e., CXCL4, IGF-1, PDGF-AB, and VEGF) in the standard/gelatinous- compared to the dry/compressed group. L-PRF in its optimal standard/gelatinous-type matrix can store and deliver locally specific healing growth factors for up to 28 days and may be a useful adjunct in rotator cuff repair.

In-vitro release pharmacokinetics of amikacin, teicoplanin and polyhexanide in a platelet rich fibrin-layer (PRF-a laboratory evaluation of a modern, autologous wound treatment.

Directory of Open Access Journals (Sweden)

Daniela Knafl

Full Text Available Platelet rich fibrin (PRF is an autologous fibrin glue, produced from patients' blood, which, besides intraoperative use, has applications in the treatment of infected wounds. The combination with antimicrobial agents results in a prolonged antibacterial effect allowing for wound dressing change intervals of seven days even in infected wounds. The aim of this study was to evaluate release kinetics of amikacin, teicoplanin or polyhexanide from a PRF-layer.PRF mixed with teicoplanin, amikacin or polyhexanide was sprayed on a silicon gauze patch and put on a colombia agar with bacteria with known minimal inhibitory concentration (MIC and incubated for 24 hours and afterwards transferred to another agar with the same bacterial strain. Inhibition zones were measured every 24 hours. This was repeated on 7 consecutive days. Antibiotic concentrations were calculated by interpolation.More than 1000 mg/L teicoplanin were released within the first 24 hours and 28.22 mg/L after 168 hours. Amikacin release was above 10,000 mg/L within the first 24 hours and still 120.8 mg/L after 120 hours. A release of polyhexanide could be verified for the first 24 hours only. Consequently teicoplanin and amikacin released from PRF showed antimicrobial in-vitro effects for almost a week, whereas an antimicrobial effect of polyhexanide could only be verified for the first 24 hours.Our Results show that a weekly dressing regimen may be justified in wounds treated with PRF plus amikacin or teicoplanin, since bacteria will be eradicated over a considerable period of time after a single application of PRF.

Population receptive field (pRF) measurements of chromatic responses in human visual cortex using fMRI.

Science.gov (United States)

Welbourne, Lauren E; Morland, Antony B; Wade, Alex R

2018-02-15

The spatial sensitivity of the human visual system depends on stimulus color: achromatic gratings can be resolved at relatively high spatial frequencies while sensitivity to isoluminant color contrast tends to be more low-pass. Models of early spatial vision often assume that the receptive field size of pattern-sensitive neurons is correlated with their spatial frequency sensitivity - larger receptive fields are typically associated with lower optimal spatial frequency. A strong prediction of this model is that neurons coding isoluminant chromatic patterns should have, on average, a larger receptive field size than neurons sensitive to achromatic patterns. Here, we test this assumption using functional magnetic resonance imaging (fMRI). We show that while spatial frequency sensitivity depends on chromaticity in the manner predicted by behavioral measurements, population receptive field (pRF) size measurements show no such dependency. At any given eccentricity, the mean pRF size for neuronal populations driven by luminance, opponent red/green and S-cone isolating contrast, are identical. Changes in pRF size (for example, an increase with eccentricity and visual area hierarchy) are also identical across the three chromatic conditions. These results suggest that fMRI measurements of receptive field size and spatial resolution can be decoupled under some circumstances - potentially reflecting a fundamental dissociation between these parameters at the level of neuronal populations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Sphere-forming cell subpopulations with cancer stem cell properties in human hepatoma cell lines

Directory of Open Access Journals (Sweden)

Chen Lei

2011-06-01

Full Text Available Abstract Background Cancer stem cells (CSCs are regarded as the cause of tumor formation and recurrence. The isolation and identification of CSCs could help to develop novel therapeutic strategies specifically targeting CSCs. Methods Human hepatoma cell lines were plated in stem cell conditioned culture system allowed for sphere forming. To evaluate the stemness characteristics of spheres, the self-renewal, proliferation, chemoresistance, tumorigenicity of the PLC/PRF/5 sphere-forming cells, and the expression levels of stem cell related proteins in the PLC/PRF/5 sphere-forming cells were assessed, comparing with the parental cells. The stem cell RT-PCR array was performed to further explore the biological properties of liver CSCs. Results The PLC/PRF/5, MHCC97H and HepG2 cells could form clonal nonadherent 3-D spheres and be serially passaged. The PLC/PRF/5 sphere-forming cells possessed a key criteria that define CSCs: persistent self-renewal, extensive proliferation, drug resistance, overexpression of liver CSCs related proteins (Oct3/4, OV6, EpCAM, CD133 and CD44. Even 500 sphere-forming cells were able to form tumors in NOD/SCID mice, and the tumor initiating capability was not decreased when spheres were passaged. Besides, downstream proteins DTX1 and Ep300 of the CSL (CBF1 in humans, Suppressor of hairless in Drosophila and LAG1 in C. elegans -independent Notch signaling pathway were highly expressed in the spheres, and a gamma-secretase inhibitor MRK003 could significantly inhibit the sphere formation ability. Conclusions Nonadherent tumor spheres from hepatoma cell lines cultured in stem cell conditioned medium possess liver CSC properties, and the CSL-independent Notch signaling pathway may play a role in liver CSCs.

Blending Behavior of Ethanol with PRF 84 and FACE A Gasoline in HCCI Combustion Mmode

KAUST Repository

Waqas, Muhammad Umer; Atef, Nour; Singh, Eshan; Masurier, Jean-Baptiste; Sarathy, Mani; Johansson, Bengt

2017-01-01

but the chemical effect responsible for the non-linear blending behavior of ethanol with PRF 84 and FACE A was not understood. Hence, in this study the experimental measurements were simulated using zero-dimensional HCCI engine model with detailed chemistry

Purification of Contaminated MIL-PRF-83282 Hydraulic Fluid Using the Pall Purifier and Multiple Process Configurations (Preprint)

National Research Council Canada - National Science Library

Snyder, Jr., Carl E; Gschwender, Lois J; Gunderson, Stephen L; Fultz, George W

2006-01-01

.... This report describes a project that evaluated the effectiveness of various hydraulic fluid purification process configurations on the removal of water and particulate contaminants from MIL-PRF-83282...

High PRF ultrafast sliding compound doppler imaging: fully qualitative and quantitative analysis of blood flow

Science.gov (United States)

Kang, Jinbum; Jang, Won Seuk; Yoo, Yangmo

2018-02-01

Ultrafast compound Doppler imaging based on plane-wave excitation (UCDI) can be used to evaluate cardiovascular diseases using high frame rates. In particular, it provides a fully quantifiable flow analysis over a large region of interest with high spatio-temporal resolution. However, the pulse-repetition frequency (PRF) in the UCDI method is limited for high-velocity flow imaging since it has a tradeoff between the number of plane-wave angles (N) and acquisition time. In this paper, we present high PRF ultrafast sliding compound Doppler imaging method (HUSDI) to improve quantitative flow analysis. With the HUSDI method, full scanline images (i.e. each tilted plane wave data) in a Doppler frame buffer are consecutively summed using a sliding window to create high-quality ensemble data so that there is no reduction in frame rate and flow sensitivity. In addition, by updating a new compounding set with a certain time difference (i.e. sliding window step size or L), the HUSDI method allows various Doppler PRFs with the same acquisition data to enable a fully qualitative, retrospective flow assessment. To evaluate the performance of the proposed HUSDI method, simulation, in vitro and in vivo studies were conducted under diverse flow circumstances. In the simulation and in vitro studies, the HUSDI method showed improved hemodynamic representations without reducing either temporal resolution or sensitivity compared to the UCDI method. For the quantitative analysis, the root mean squared velocity error (RMSVE) was measured using 9 angles (-12° to 12°) with L of 1-9, and the results were found to be comparable to those of the UCDI method (L  =  N  =  9), i.e.  ⩽0.24 cm s-1, for all L values. For the in vivo study, the flow data acquired from a full cardiac cycle of the femoral vessels of a healthy volunteer were analyzed using a PW spectrogram, and arterial and venous flows were successfully assessed with high Doppler PRF (e.g. 5 kHz at L�

High PRF ultrafast sliding compound doppler imaging: fully qualitative and quantitative analysis of blood flow.

Science.gov (United States)

Kang, Jinbum; Jang, Won Seuk; Yoo, Yangmo

2018-02-09

Ultrafast compound Doppler imaging based on plane-wave excitation (UCDI) can be used to evaluate cardiovascular diseases using high frame rates. In particular, it provides a fully quantifiable flow analysis over a large region of interest with high spatio-temporal resolution. However, the pulse-repetition frequency (PRF) in the UCDI method is limited for high-velocity flow imaging since it has a tradeoff between the number of plane-wave angles (N) and acquisition time. In this paper, we present high PRF ultrafast sliding compound Doppler imaging method (HUSDI) to improve quantitative flow analysis. With the HUSDI method, full scanline images (i.e. each tilted plane wave data) in a Doppler frame buffer are consecutively summed using a sliding window to create high-quality ensemble data so that there is no reduction in frame rate and flow sensitivity. In addition, by updating a new compounding set with a certain time difference (i.e. sliding window step size or L), the HUSDI method allows various Doppler PRFs with the same acquisition data to enable a fully qualitative, retrospective flow assessment. To evaluate the performance of the proposed HUSDI method, simulation, in vitro and in vivo studies were conducted under diverse flow circumstances. In the simulation and in vitro studies, the HUSDI method showed improved hemodynamic representations without reducing either temporal resolution or sensitivity compared to the UCDI method. For the quantitative analysis, the root mean squared velocity error (RMSVE) was measured using 9 angles (-12° to 12°) with L of 1-9, and the results were found to be comparable to those of the UCDI method (L  =  N  =  9), i.e.  ⩽0.24 cm s -1 , for all L values. For the in vivo study, the flow data acquired from a full cardiac cycle of the femoral vessels of a healthy volunteer were analyzed using a PW spectrogram, and arterial and venous flows were successfully assessed with high Doppler PRF (e.g. 5 kHz at L�

Noninvasive MRI thermometry with the proton resonance frequency (PRF) method: in vivo results in human muscle

DEFF Research Database (Denmark)

De Poorter, J; De Wagter, C; De Deene, Y

1995-01-01

The noninvasive thermometry method is based on the temperature dependence of the proton resonance frequency (PRF). High-quality temperature images can be obtained from phase information of standard gradient-echo sequences with an accuracy of 0.2 degrees C in phantoms. This work was focused on the...

Determination of factor of hydrogen permeation reduction (PRF) for different protective coatings over vanadium

International Nuclear Information System (INIS)

Afanasyev, S.; Kulsartov, T.; Shestakov, V.; Chikhray, Y.; Smith, D.

2002-01-01

Selection of structural materials for liquid-metal system as well as for another system and constructions of nuclear energy plants must be carried out and based on specified demands depending on conditions of these materials functioning. Specific demand is its compatibility with liquid metals. Design of reactors with liquid-metal coolant (Li, PbLi 17 ) which reproduces tritium arise additional demand to structural materials. This demand is a creation of structural material or protective barrier with minimum acceptable value of tritium permeation through itself or with maximum permeation reduction factor (PRF). Vanadium and vanadium alloys are supposed to be use as a blanket structural material in such nuclear energy plants. Worked out at first stage of studies vanadium coatings should have stability of its characteristics at temperature 800 deg. C under influence of hydrogen. Given work shows the experimental results on testing of protective coatings over vanadium: glass-ceramic coating and CaO-base coating. PRF for every coating and its changes depending on thermo-capacity of vanadium sample with coating was determined by method of hydrogen permeation. The results of experiments would be used at the development of cooling loops of reactor core protection with liquid-metal coolant

Metabolic Genetic Screens Reveal Multidimensional Regulation of Virulence Gene Expression in Listeria monocytogenes and an Aminopeptidase That Is Critical for PrfA Protein Activation.

Science.gov (United States)

Friedman, Sivan; Linsky, Marika; Lobel, Lior; Rabinovich, Lev; Sigal, Nadejda; Herskovits, Anat A

2017-06-01

Listeria monocytogenes is an environmental saprophyte and intracellular bacterial pathogen. Upon invading mammalian cells, the bacterium senses abrupt changes in its metabolic environment, which are rapidly transduced to regulation of virulence gene expression. To explore the relationship between L. monocytogenes metabolism and virulence, we monitored virulence gene expression dynamics across a library of genetic mutants grown under two metabolic conditions known to activate the virulent state: charcoal-treated rich medium containing glucose-1-phosphate and minimal defined medium containing limiting concentrations of branched-chain amino acids (BCAAs). We identified over 100 distinct mutants that exhibit aberrant virulence gene expression profiles, the majority of which mapped to nonessential metabolic genes. Mutants displayed enhanced, decreased, and early and late virulence gene expression profiles, as well as persistent levels, demonstrating a high plasticity in virulence gene regulation. Among the mutants, one was noteworthy for its particularly low virulence gene expression level and mapped to an X-prolyl aminopeptidase (PepP). We show that this peptidase plays a role in posttranslational activation of the major virulence regulator, PrfA. Specifically, PepP mediates recruitment of PrfA to the cytoplasmic membrane, a step identified as critical for PrfA protein activation. This study establishes a novel step in the complex mechanism of PrfA activation and further highlights the cross regulation of metabolism and virulence. Copyright © 2017 American Society for Microbiology.

Personality Correlates of Self-Report, Role-Playing, and In Vivo Measures of Assertiveness.

Science.gov (United States)

Green, Samuel B.; And Others

1979-01-01

Undergraduates completed self-report inventories of assertiveness, participated in behavior role-playing tasks and in vivo measures of assertiveness, and completed the Personality Research Form E (PRF-E). Of 22 PRF-E scales, 11 had at least one significant correlation with assertiveness measures. Some composites of PRF-E scales were related to…

Increased vascularization during early healing after biologic augmentation in repair of chronic rotator cuff tears using autologous leukocyte- and platelet-rich fibrin (L-PRF): a prospective randomized controlled pilot trial.

Science.gov (United States)

Zumstein, Matthias A; Rumian, Adam; Lesbats, Virginie; Schaer, Michael; Boileau, Pascal

2014-01-01

We hypothesized that arthroscopic rotator cuff repairs using leukocyte- and platelet-rich fibrin (L-PRF) in a standardized, modified protocol is technically feasible and results in a higher vascularization response and watertight healing rate during early healing. Twenty patients with chronic rotator cuff tears were randomly assigned to 2 treatment groups. In the test group (N = 10), L-PRF was added in between the tendon and the bone during arthroscopic rotator cuff repair. The second group served as control (N = 10). They received the same arthroscopic treatment without the use of L-PRF. We used a double-row tension band technique. Clinical examinations including subjective shoulder value, visual analog scale, Constant, and Simple Shoulder Test scores and measurement of the vascularization with power Doppler ultrasonography were made at 6 and 12 weeks. There have been no postoperative complications. At 6 and 12 weeks, there was no significant difference in the clinical scores between the test and the control groups. The mean vascularization index of the surgical tendon-to-bone insertions was always significantly higher in the L-PRF group than in the contralateral healthy shoulders at 6 and 12 weeks (P = .0001). Whereas the L-PRF group showed a higher vascularization compared with the control group at 6 weeks (P = .001), there was no difference after 12 weeks of follow-up (P = .889). Watertight healing was obtained in 89% of the repaired cuffs. Arthroscopic rotator cuff repair with the application of L-PRF is technically feasible and yields higher early vascularization. Increased vascularization may potentially predispose to an increased and earlier cellular response and an increased healing rate. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Blending Behavior of Ethanol with PRF 84 and FACE A Gasoline in HCCI Combustion Mmode

KAUST Repository

Waqas, Muhammad Umer

2017-09-04

The blending of ethanol with PRF (Primary reference fuel) 84 was investigated and compared with FACE (Fuels for Advanced Combustion Engines) A gasoline surrogate which has a RON of 83.9. Previously, experiments were performed at four HCCI conditions but the chemical effect responsible for the non-linear blending behavior of ethanol with PRF 84 and FACE A was not understood. Hence, in this study the experimental measurements were simulated using zero-dimensional HCCI engine model with detailed chemistry in CHEMKIN PRO. Ethanol was used as an octane booster for the above two base fuels in volume concentration of 0%, 2%, 5% and 10%. The geometrical data and the intake valve closure conditions were used to match the simulated combustion phasing with the experiments. Low temperature heat release (LTHR) was detected by performing heat release analysis. LTHR formation depended on the base fuel type and the engine operating conditions suggesting that the base fuel composition has an important role in the formation of LTHR. The effect of ethanol on LTHR was explained by low temperature chemistry reactions and OH/HO evolution. A strong correlation of low temperature oxidation reactions of base fuels with ethanol was found to be responsible for the observed blending effects.

Imaging the Moho beneath Sedimentary Basins: A Comparative Study of Virtual Deep Seismic Sounding (VDSS) and P Wave Receiver Functions (PRF)

Science.gov (United States)

Liu, T.; Klemperer, S. L.; Yu, C.; Ning, J.

2017-12-01

In the past decades, P wave receiver functions (PRF) have been routinely used to image the Moho, although it is well known that PRFs are susceptible to contamination from sedimentary multiples. Recently, Virtual Deep Seismic Sounding (VDSS) emerged as a novel method to image the Moho. However, despite successful applications of VDSS on multiple datasets from different areas, how sedimentary basins affect the waveforms of post-critical SsPmp, the Moho reflection phase used in VDSS, is not widely understood. Here, motivated by a dataset collected in the Ordos plateau, which shows distinct effects of sedimentary basins on SsPmp and Pms waveforms, we use synthetic seismograms to study the effects of sedimentary basins on SsPmp and Pms, the phases used in VDSS and PRF respectively. The results show that when the sedimentary thickness is on the same order of magnitude as the dominant wavelength of the incident S wave, SsPmp amplitude decreases significantly with S velocity of the sedimentary layer, whereas increasing sedimentary thickness has little effect in SsPmp amplitude. Our explanation is that the low S velocity layer at the virtual source reduces the incident angle of S wave at the free surface, thus decreases the S-to-P reflection coefficient at the virtual source. In addition, transmission loss associated with the bottom of sedimentary basins also contributes to reducing SsPmp amplitude. This explains not only our observations from the Ordos plateau, but also observations from other areas where post-critical SsPmp is expected to be observable, but instead is too weak to be identified. As for Pms, we observe that increasing sedimentary thickness and decreasing sedimentary velocities both can cause interference between sedimentary multiples and Pms, rendering the Moho depths inferred from Pms arrival times unreliable. The reason is that although Pms amplitude does not vary with sedimentary thickness or velocities, as sedimentary velocities decrease and thickness

Progeria Research Foundation, Inc.

Science.gov (United States)

... Million Views – Celebrate with Us! Sam’s talk, "My Philosophy for a Happy Life", has inspired over 25 ... July 11th, 2016 | 0 Comments PRF Continues Aggressive Research Agenda Events November 25, 2017 in Verona, NJ: ...

Pain Research Forum: Application of Scientific Social Media Frameworks in Neuroscience

Directory of Open Access Journals (Sweden)

Sudeshna eDas

2014-03-01

Full Text Available Background: Social media has the potential to accelerate the pace of biomedical research through online collaboration, discussions and faster sharing of information. Focused web-based scientific social collaboratories such as the Alzheimer Research Forum have been successful in engaging scientists in open discussions of the latest research and identifying gaps in knowledge. However, until recently, tools to rapidly create such communities and provide high-bandwidth information exchange between collaboratories in related fields did not exist. Methods: We have addressed this need by constructing a reusable framework to build online biomedical communities, based on Drupal, an open-source content management system. The framework incorporates elements of Semantic Web technology combined with social media. Here we present, as an exemplar of a web community built on our framework, the Pain Research Forum (PRF. PRF is a community of chronic pain researchers, established with the goal of fostering collaboration and communication among pain researchers. Results: Launched in 2011, PRF has over 1,300 registered members with permission to submit content. It currently hosts over 150 topical news articles on research; more than 30 active or archived forum discussions and journal club features; a webinar series; an editor-curated weekly updated listing of relevant papers; and several other resources for the pain research community. All content is licensed for reuse under a Creative Commons license; the software is freely available. The framework was reused to develop other sites, notably the Multiple Sclerosis Discovery Forum and StemBook.Discussion: Web-based collaboratories are a crucial integrative tool supporting rapid information transmission and translation in several important research areas. In this article, we discuss the success factors, lessons learned and ongoing challenges in using PRF as a driving force to develop tools for online collaboration in

Pain Research Forum: application of scientific social media frameworks in neuroscience.

Science.gov (United States)

Das, Sudeshna; McCaffrey, Patricia G; Talkington, Megan W T; Andrews, Neil A; Corlosquet, Stéphane; Ivinson, Adrian J; Clark, Tim

2014-01-01

Social media has the potential to accelerate the pace of biomedical research through online collaboration, discussions, and faster sharing of information. Focused web-based scientific social collaboratories such as the Alzheimer Research Forum have been successful in engaging scientists in open discussions of the latest research and identifying gaps in knowledge. However, until recently, tools to rapidly create such communities and provide high-bandwidth information exchange between collaboratories in related fields did not exist. We have addressed this need by constructing a reusable framework to build online biomedical communities, based on Drupal, an open-source content management system. The framework incorporates elements of Semantic Web technology combined with social media. Here we present, as an exemplar of a web community built on our framework, the Pain Research Forum (PRF) (http://painresearchforum.org). PRF is a community of chronic pain researchers, established with the goal of fostering collaboration and communication among pain researchers. Launched in 2011, PRF has over 1300 registered members with permission to submit content. It currently hosts over 150 topical news articles on research; more than 30 active or archived forum discussions and journal club features; a webinar series; an editor-curated weekly updated listing of relevant papers; and several other resources for the pain research community. All content is licensed for reuse under a Creative Commons license; the software is freely available. The framework was reused to develop other sites, notably the Multiple Sclerosis Discovery Forum (http://msdiscovery.org) and StemBook (http://stembook.org). Web-based collaboratories are a crucial integrative tool supporting rapid information transmission and translation in several important research areas. In this article, we discuss the success factors, lessons learned, and ongoing challenges in using PRF as a driving force to develop tools for

Personality Patterns of Physicians in Person-Oriented and Technique-Oriented Specialties

Science.gov (United States)

Borges, Nicole J.; Gibson, Denise D.

2005-01-01

This study investigated differences in personality patterns between person-oriented and technique-oriented physicians. It tested an integrative framework by converting the scores on the Personality Research Form (PRF) to the Big-Five factors and built a predictive model of group membership in clinical specialty area. PRF scores from 238 physicians…

Cord blood PRF1 methylation patterns and risk of lower respiratory tract infections in infants: findings from the Ulm Birth Cohort.

Science.gov (United States)

Elgizouli, Magdeldin; Logan, Chad; Nieters, Alexandra; Brenner, Hermann; Rothenbacher, Dietrich

2015-01-01

Lower respiratory tract infections (LRTIs) are a major cause of morbidity in children. DNA methylation provides a mechanism for transmitting environmental effects on the genome, but its potential role in LRTIs is not well studied. We investigated the methylation pattern of an enhancer region of the immune effector gene perforin-1 (PRF1), which encodes a cytolytic molecule of cytotoxic T lymphocytes (CTLs) and natural killer cells (NK), in cord blood DNA of children recruited in a German birth cohort in association with LRTIs in the first year of life.Pyrosequencing was used to determine the methylation levels of target cytosine-phosphate-guanines (CpGs) in a 2-stage case-control design. Cases were identified as children who developed ≥2 episodes of physician-recorded LRTIs during the first year of life and controls as children who had none. Discovery (n = 87) and replication (n = 90) sets were arranged in trios of 1 case and 2 controls matched for sex and season of birth.Logistic regression analysis revealed higher levels of methylation at a CpG that corresponds to a signal transducer and activator of transcription 5 (STAT5) responsive enhancer in the discovery (odds ratio [OR] per 1% methylation difference 1.24, 95% confidence interval [CI] 1.03-1.50) and replication (OR per 1% methylation difference 1.25, 95% CI 1.04-1.50) sets. Adjustment for having siblings blood PRF1 enhancer methylation patterns and subsequent risk of LRTIs in infants. Methylation levels at specific CpGs of the PRF1 enhancer varied according to maternal and family environmental factors suggesting a role for DNA methylation in mediating environmental influences on gene function.

On the effect of injection timing on the ignition of lean PRF/air/EGR mixtures under direct dual fuel stratification conditions

KAUST Repository

Luong, Minh Bau; Sankaran, Ramanan; Yu, Gwang Hyeon; Chung, Suk-Ho; Yoo, Chun Sang

2017-01-01

The ignition characteristics of lean primary reference fuel (PRF)/air/exhaust gas recirculation (EGR) mixture under reactivity-controlled compression ignition (RCCI) and direct duel fuel stratification (DDFS) conditions are investigated by 2-D direct numerical simulations (DNSs) with a 116-species reduced chemistry of the PRF oxidation. The 2-D DNSs of the DDFS combustion are performed by varying the injection timing of iso-octane (i-C8H18) with a pseudo-iso-octane (PC8H18) model together with a novel compression heating model to account for the compression heating and expansion cooling effects of the piston motion in an engine cylinder. The PC8H18 model is newly developed to mimic the timing, duration, and cooling effects of the direct injection of i-C8H18 onto a premixed background charge of PRF/air/EGR mixture with composition inhomogeneities. It is found that the RCCI combustion exhibits a very high peak heat release rate (HRR) with a short combustion duration due to the predominance of the spontaneous ignition mode of combustion. However, the DDFS combustion has much lower peak HRR and longer combustion duration regardless of the fuel injection timing compared to those of the RCCI combustion, which is primarily attributed to the sequential injection of i-C8H18. It is also found that the ignition delay of the DDFS combustion features a non-monotonic behavior with increasing fuel-injection timing due to the different effect of fuel evaporation on the low-, intermediate-, and high-temperature chemistry of the PRF oxidation. The budget and Damköhler number analyses verify that although a mixed combustion mode of deflagration and spontaneous ignition exists during the early phase of the DDFS combustion, the spontaneous ignition becomes predominant during the main combustion, and hence, the spread-out of heat release rate in the DDFS combustion is mainly governed by the direct injection process of i-C8H18. Finally, a misfire is observed for the DDFS combustion when

On the effect of injection timing on the ignition of lean PRF/air/EGR mixtures under direct dual fuel stratification conditions

KAUST Repository

Luong, Minh Bau

2017-06-10

The ignition characteristics of lean primary reference fuel (PRF)/air/exhaust gas recirculation (EGR) mixture under reactivity-controlled compression ignition (RCCI) and direct duel fuel stratification (DDFS) conditions are investigated by 2-D direct numerical simulations (DNSs) with a 116-species reduced chemistry of the PRF oxidation. The 2-D DNSs of the DDFS combustion are performed by varying the injection timing of iso-octane (i-C8H18) with a pseudo-iso-octane (PC8H18) model together with a novel compression heating model to account for the compression heating and expansion cooling effects of the piston motion in an engine cylinder. The PC8H18 model is newly developed to mimic the timing, duration, and cooling effects of the direct injection of i-C8H18 onto a premixed background charge of PRF/air/EGR mixture with composition inhomogeneities. It is found that the RCCI combustion exhibits a very high peak heat release rate (HRR) with a short combustion duration due to the predominance of the spontaneous ignition mode of combustion. However, the DDFS combustion has much lower peak HRR and longer combustion duration regardless of the fuel injection timing compared to those of the RCCI combustion, which is primarily attributed to the sequential injection of i-C8H18. It is also found that the ignition delay of the DDFS combustion features a non-monotonic behavior with increasing fuel-injection timing due to the different effect of fuel evaporation on the low-, intermediate-, and high-temperature chemistry of the PRF oxidation. The budget and Damköhler number analyses verify that although a mixed combustion mode of deflagration and spontaneous ignition exists during the early phase of the DDFS combustion, the spontaneous ignition becomes predominant during the main combustion, and hence, the spread-out of heat release rate in the DDFS combustion is mainly governed by the direct injection process of i-C8H18. Finally, a misfire is observed for the DDFS combustion when

Progeria Research Foundation Diagnostic Testing Program

Science.gov (United States)

... Share the DVD Meet the Kids in the Movie Bring LATS to the classroom! Close News/Events ... this could severely affect their research results and interpretation. Through the PRF Diagnostics Program, each cell line ...

Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.

Directory of Open Access Journals (Sweden)

Ormeño-Orrillo Ernesto

2012-12-01

Full Text Available Abstract Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical

Compilation of PRF Canyon Floor Pan Sample Analysis Results

Energy Technology Data Exchange (ETDEWEB)

Pool, Karl N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wahl, Jon H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, Lawrence R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Deborah S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McNamara, Bruce K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scheele, Randall D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Delegard, Calvin H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Garrett N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-06-30

On September 28, 2015, debris collected from the PRF (236-Z) canyon floor, Pan J, was observed to exhibit chemical reaction. The material had been transferred from the floor pan to a collection tray inside the canyon the previous Friday. Work in the canyon was stopped to allow Industrial Hygiene to perform monitoring of the material reaction. Canyon floor debris that had been sealed out was sequestered at the facility, a recovery plan was developed, and drum inspections were initiated to verify no additional reactions had occurred. On October 13, in-process drums containing other Pan J material were inspected and showed some indication of chemical reaction, limited to discoloration and degradation of inner plastic bags. All Pan J material was sealed back into the canyon and returned to collection trays. Based on the high airborne levels in the canyon during physical debris removal, ETGS (Encapsulation Technology Glycerin Solution) was used as a fogging/lock-down agent. On October 15, subject matter experts confirmed a reaction had occurred between nitrates (both Plutonium Nitrate and Aluminum Nitrate Nonahydrate (ANN) are present) in the Pan J material and the ETGS fixative used to lower airborne radioactivity levels during debris removal. Management stopped the use of fogging/lock-down agents containing glycerin on bulk materials, declared a Management Concern, and initiated the Potential Inadequacy in the Safety Analysis determination process. Additional drum inspections and laboratory analysis of both reacted and unreacted material are planned. This report compiles the results of many different sample analyses conducted by the Pacific Northwest National Laboratory on samples collected from the Plutonium Reclamation Facility (PRF) floor pans by the CH2MHill’s Plateau Remediation Company (CHPRC). Revision 1 added Appendix G that reports the results of the Gas Generation Rate and methodology. The scope of analyses requested by CHPRC includes the determination of

Blending Octane Number of Toluene with Gasoline-like and PRF Fuels in HCCI Combustion Mode

KAUST Repository

Waqas, Muhammad Umer

2018-04-03

Future internal combustion engines demand higher efficiency but progression towards this is limited by the phenomenon called knock. A possible solution for reaching high efficiency is Octane-on-Demand (OoD), which allows to customize the antiknock quality of a fuel through blending of high-octane fuel with a low octane fuel. Previous studies on Octane-on-Demand highlighted efficiency benefits depending on the combination of low octane fuel with high octane booster. The author recently published works with ethanol and methanol as high-octane fuels. The results of this work showed that the composition and octane number of the low octane fuel is significant for the blending octane number of both ethanol and methanol. This work focuses on toluene as the high octane fuel (RON 120). Aromatics offers anti-knock quality and with high octane number than alcohols, this work will address if toluene can provide higher octane enhancement. Our aim is to investigate the impact of three gasoline-like fuels and two Primary Reference Fuels (PRFs). More specifically, fuels are FACE (Fuels for Advanced Combustion Engines) I, FACE J, FACE A, PRF 70 and PRF 84. A CFR engine was used to conduct the experiments in HCCI mode. For this combustion mode, the engine operated at four specific conditions based on RON and MON conditions. The octane numbers corresponding to four HCCI numbers were obtained for toluene concentration of 0, 2, 5, 10, 15 and 20%. Results show that the blending octane number of toluene varies non-linearly and linearly with the increase in toluene concentration depending on the base fuel, experimental conditions and the concentration of toluene. As a result, the blending octane number can range from close to 150 with a small fraction of toluene to a number closer to that of toluene, 120, with larger fractions.

Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF) in the Healing of Simple Postextraction Sockets: A Split-Mouth Study.

Science.gov (United States)

Marenzi, Gaetano; Riccitiello, Francesco; Tia, Mariano; di Lauro, Alessandro; Sammartino, Gilberto

2015-01-01

The aim of this study was to evaluate the effects of leukocyte- and platelet-rich fibrin (L-PRF) on the pain and soft tissue healing after tooth extractions. Twenty-six patients (9 males and 17 females) were treated with multiple extractions (2 to 8), with a total of 108 extractions. This was an exploratory single blinded randomized clinical trial with a split-mouth design. The pain after the surgery was assessed in each patient by the VAS scale (1 to 10) at intervals of 24-48-72-96 hours. The soft tissue healing was clinically evaluated at 3, 7, 14, and 21 days after surgery by the same examiner surgeon, using the modified Healing Index (4 to 12). The mean value of postextraction pain was 3.2 ± 0.3 in the experimental sides and 4.1 ± 0.1 in the control sides. After 7 days from the extractions, the values of modified Healing Index in the experimental and control groups were, respectively, 4.8 ± 0.6 and 5.1 ± 0.9. The use of L-PRF in postextraction sockets filling can be proposed as a useful procedure in order to manage the postoperative pain and to promote the soft tissue healing process, reducing the early adverse effects of the inflammation.

Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF) in the Healing of Simple Postextraction Sockets: A Split-Mouth Study

Science.gov (United States)

Riccitiello, Francesco; Tia, Mariano; di Lauro, Alessandro; Sammartino, Gilberto

2015-01-01

The aim of this study was to evaluate the effects of leukocyte- and platelet-rich fibrin (L-PRF) on the pain and soft tissue healing after tooth extractions. Twenty-six patients (9 males and 17 females) were treated with multiple extractions (2 to 8), with a total of 108 extractions. This was an exploratory single blinded randomized clinical trial with a split-mouth design. The pain after the surgery was assessed in each patient by the VAS scale (1 to 10) at intervals of 24-48-72-96 hours. The soft tissue healing was clinically evaluated at 3, 7, 14, and 21 days after surgery by the same examiner surgeon, using the modified Healing Index (4 to 12). The mean value of postextraction pain was 3.2 ± 0.3 in the experimental sides and 4.1 ± 0.1 in the control sides. After 7 days from the extractions, the values of modified Healing Index in the experimental and control groups were, respectively, 4.8 ± 0.6 and 5.1 ± 0.9. The use of L-PRF in postextraction sockets filling can be proposed as a useful procedure in order to manage the postoperative pain and to promote the soft tissue healing process, reducing the early adverse effects of the inflammation. PMID:26273612

Platelet rich fibrin (Prf) and β-tricalcium phosphate with coronally advanced flap for the management of grade-II furcation defect.

Science.gov (United States)

Sambhav, Jain; Rohit, Rai; Ranjana, Mohan; Shalabh, Mehrotra

2014-07-01

Multirooted teeth offer unique and challenging problems due to the furcation area, creates situations in which routine periodontal procedures are somewhat limited and special procedures are generally required. The present case was showing the management of grade II furcation defect by platelet rich fibrin (PRF) and β-Tricalcium phosphate with coronally advanced flap. Platelet rich fibrin and β-Tricalcium phosphate with coronally advanced flap have been shown to be a promising and successful approach for the treatment of furcation defect. Its gaining clinical attachment significantly manages both the gingival recession and furcation involvement simultaneously.

Research needs in cement-based waste forms

International Nuclear Information System (INIS)

McDaniel, E.W.; Spence, R.D.; Tallent, O.K.

1990-01-01

Cement-based waste forms are one of the most widely used waste disposal options, yet definitive knowledge of the fate of the waste species inside the waste form is lacking. A fundamental understanding of the chemistry and microstructure of the waste forms would lead to a better understanding of the mass transfer of the waste species, more confidence in predicting and extrapolating waste form performance, and design of better waste forms. Better and cheaper leach tests would lead to quicker and more cost effective screening of waste form alternatives. In addition, assessment of durability may be important to predicting waste form performance in the field. It should be noted that the research needs discussed in this report are from the perspective of investigators working in applied waste management areas, while the proposed investigations are fundamental or basic. Details as to experimental methods and tools to be used in achieving the objectives of the proposed are research beyond the scope of this paper and are better filled in by others. In broad terms, the research topics discussed are correlation of cement-based waste form physical properties to performance, waste-form fundamental chemistry and microstructure, and product performance testing

The Listeria monocytogenes Bile Stimulon under Acidic Conditions Is Characterized by Strain-Specific Patterns and the Upregulation of Motility, Cell Wall Modification Functions, and the PrfA Regulon

Science.gov (United States)

Guariglia-Oropeza, Veronica; Orsi, Renato H.; Guldimann, Claudia; Wiedmann, Martin; Boor, Kathryn J.

2018-01-01

Listeria monocytogenes uses a variety of transcriptional regulation strategies to adapt to the extra-host environment, the gastrointestinal tract, and the intracellular host environment. While the alternative sigma factor SigB has been proposed to be a key transcriptional regulator that facilitates L. monocytogenes adaptation to the gastrointestinal environment, the L. monocytogenes' transcriptional response to bile exposure is not well-understood. RNA-seq characterization of the bile stimulon was performed in two L. monocytogenes strains representing lineages I and II. Exposure to bile at pH 5.5 elicited a large transcriptomic response with ~16 and 23% of genes showing differential transcription in 10403S and H7858, respectively. The bile stimulon includes genes involved in motility and cell wall modification mechanisms, as well as genes in the PrfA regulon, which likely facilitate survival during the gastrointestinal stages of infection that follow bile exposure. The fact that bile exposure induced the PrfA regulon, but did not induce further upregulation of the SigB regulon (beyond that expected by exposure to pH 5.5), suggests a model where at the earlier stages of gastrointestinal infection (e.g., acid exposure in the stomach), SigB-dependent gene expression plays an important role. Subsequent exposure to bile induces the PrfA regulon, potentially priming L. monocytogenes for subsequent intracellular infection stages. Some members of the bile stimulon showed lineage- or strain-specific distribution when 27 Listeria genomes were analyzed. Even though sigB null mutants showed increased sensitivity to bile, the SigB regulon was not found to be upregulated in response to bile beyond levels expected by exposure to pH 5.5. Comparison of wildtype and corresponding ΔsigB strains newly identified 26 SigB-dependent genes, all with upstream putative SigB-dependent promoters. PMID:29467736

Osteoblastic mesenchymal stem cell sheet combined with Choukroun platelet-rich fibrin induces bone formation at an ectopic site.

Science.gov (United States)

Wang, Zhifa; Weng, Yanming; Lu, Shengjun; Zong, Chunlin; Qiu, Jianyong; Liu, Yanpu; Liu, Bin

2015-08-01

To analyze the effects of platelet-rich fibrin (PRF) on mesenchymal stem cells (MSCs) in vitro and investigate in vivo bone formation by MSC sheets with PRF. Cell proliferation and expression of osteogenesis-related genes within MSC sheets were assessed upon exposure to PRF from the same donors. We then injected MSC sheet fragments with or without PRF subcutaneously in nude mice and assessed bone formation by micro-computed tomography and histological analyses. PRF significantly stimulated MSC proliferation and osteogenesis in vitro. MSC sheets injected with or without PRF formed new bone, but those with PRF produced significantly more and denser bone. MSC sheets can be used to generate tissue engineered bone upon injection, and PRF increases the osteogenic capacity of MSC sheets in vitro and in vivo. © 2014 Wiley Periodicals, Inc.

The heat-compression technique for the conversion of platelet-rich fibrin preparation to a barrier membrane with a reduced rate of biodegradation.

Science.gov (United States)

Kawase, Tomoyuki; Kamiya, Mana; Kobayashi, Mito; Tanaka, Takaaki; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

2015-05-01

Platelet-rich fibrin (PRF) was developed as an advanced form of platelet-rich plasma to eliminate xenofactors, such as bovine thrombin, and it is mainly used as a source of growth factor for tissue regeneration. Furthermore, although a minor application, PRF in a compressed membrane-like form has also been used as a substitute for commercially available barrier membranes in guided-tissue regeneration (GTR) treatment. However, the PRF membrane is resorbed within 2 weeks or less at implantation sites; therefore, it can barely maintain sufficient space for bone regeneration. In this study, we developed and optimized a heat-compression technique and tested the feasibility of the resulting PRF membrane. Freshly prepared human PRF was first compressed with dry gauze and subsequently with a hot iron. Biodegradability was microscopically examined in vitro by treatment with plasmin at 37°C or in vivo by subcutaneous implantation in nude mice. Compared with the control gauze-compressed PRF, the heat-compressed PRF appeared plasmin-resistant and remained stable for longer than 10 days in vitro. Additionally, in animal implantation studies, the heat-compressed PRF was observed at least for 3 weeks postimplantation in vivo whereas the control PRF was completely resorbed within 2 weeks. Therefore, these findings suggest that the heat-compression technique reduces the rate of biodegradation of the PRF membrane without sacrificing its biocompatibility and that the heat-compressed PRF membrane easily could be prepared at chair-side and applied as a barrier membrane in the GTR treatment. © 2014 Wiley Periodicals, Inc.

Influence of geometric and material properties on artifacts generated by interventional MRI devices: Relevance to PRF-shift thermometry

Energy Technology Data Exchange (ETDEWEB)

Tatebe, Ken, E-mail: Ken.Tatebe@gmail.com [Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 (United States); Ramsay, Elizabeth; Kazem, Mohammad; Peikari, Hamed [Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N3M5 (Canada); Mougenot, Charles [Philips Healthcare, 281 Hillmount Road, Markham, Ontario L6C 2S3 (Canada); Bronskill, Michael [Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N3M5, Canada and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario M5G2M9 (Canada); Chopra, Rajiv [Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 (United States); Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 (United States); Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N3M5 (Canada); Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario M5G2M9 (Canada)

2016-01-15

Purpose: Magnetic resonance imaging (MRI) is capable of providing valuable real-time feedback during medical procedures, partly due to the excellent soft-tissue contrast available. Several technical hurdles still exist to seamless integration of medical devices with MRI due to incompatibility of most conventional devices with this imaging modality. In this study, the effect of local perturbations in the magnetic field caused by the magnetization of medical devices was examined using finite element analysis modeling. As an example, the influence of the geometric and material characteristics of a transurethral high-intensity ultrasound applicator on temperature measurements using proton resonance frequency (PRF)-shift thermometry was investigated. Methods: The effect of local perturbations in the magnetic field, caused by the magnetization of medical device components, was examined using finite element analysis modeling. The thermometry artifact generated by a transurethral ultrasound applicator was simulated, and these results were validated against analytic models and scans of an applicator in a phantom. Several parameters were then varied to identify which most strongly impacted the level of simulated thermometry artifact, which varies as the applicator moves over the course of an ablative high-intensity ultrasound treatment. Results: Key design parameters identified as having a strong influence on the magnitude of thermometry artifact included the susceptibility of materials and their volume. The location of components was also important, particularly when positioned to maximize symmetry of the device. Finally, the location of component edges and the inclination of the device relative to the magnetic field were also found to be important factors. Conclusions: Previous design strategies to minimize thermometry artifact were validated, and novel design strategies were identified that substantially reduce PRF-shift thermometry artifacts for a variety of device

Influence of geometric and material properties on artifacts generated by interventional MRI devices: Relevance to PRF-shift thermometry

International Nuclear Information System (INIS)

Tatebe, Ken; Ramsay, Elizabeth; Kazem, Mohammad; Peikari, Hamed; Mougenot, Charles; Bronskill, Michael; Chopra, Rajiv

2016-01-01

Purpose: Magnetic resonance imaging (MRI) is capable of providing valuable real-time feedback during medical procedures, partly due to the excellent soft-tissue contrast available. Several technical hurdles still exist to seamless integration of medical devices with MRI due to incompatibility of most conventional devices with this imaging modality. In this study, the effect of local perturbations in the magnetic field caused by the magnetization of medical devices was examined using finite element analysis modeling. As an example, the influence of the geometric and material characteristics of a transurethral high-intensity ultrasound applicator on temperature measurements using proton resonance frequency (PRF)-shift thermometry was investigated. Methods: The effect of local perturbations in the magnetic field, caused by the magnetization of medical device components, was examined using finite element analysis modeling. The thermometry artifact generated by a transurethral ultrasound applicator was simulated, and these results were validated against analytic models and scans of an applicator in a phantom. Several parameters were then varied to identify which most strongly impacted the level of simulated thermometry artifact, which varies as the applicator moves over the course of an ablative high-intensity ultrasound treatment. Results: Key design parameters identified as having a strong influence on the magnitude of thermometry artifact included the susceptibility of materials and their volume. The location of components was also important, particularly when positioned to maximize symmetry of the device. Finally, the location of component edges and the inclination of the device relative to the magnetic field were also found to be important factors. Conclusions: Previous design strategies to minimize thermometry artifact were validated, and novel design strategies were identified that substantially reduce PRF-shift thermometry artifacts for a variety of device

Inhibitory effect of genistein on PLC/PRF5 hepatocellular carcinoma cell line

Directory of Open Access Journals (Sweden)

Mehdi Nikbakht Dastjerdi

2015-01-01

Full Text Available Background: Natural compounds including flavonoids like genistein (GE are able to inhibit cell proliferation and induce apoptosis. GE is the main representative of these groups. GE inhibits carcinogenic tumors such as colon, stomach, lung, and pancreas tumors. The aim of the present study was to analyze the apoptotic effect of GE in the hepatocellular carcinoma (HCC PLC/PRF5 cell line. Methods: Cells were treated with various doses of GE (1, 5, 10, 25, 50, 75, and 100 μM/L at different times (24, 48, and 72 h and the MTT assay was commonly used. Furthermore, cells were treated with single dose of GE (25 μM at different times and flow cytometry was performed. Results: GE inhibited the growth of liver cancer cells significantly with a time- and dose-dependent manner. The percentage of living cells in GE treatment groups with a concentration of 25 μM at different times were 53, 48 and 47%, respectively (P < 0.001. Result of flow cytometry demonstrated that GE at a 25 μM concentration induces apoptosis significantly in a time-dependent manner. The percentage of apoptotic cells at different times were 44, 56, and 60%, respectively (P < 0.001. Conclusions: GE can significantly inhibit the growth of HCC cells and plays a significant role in apoptosis of this cell line.

Reduction of relative centrifugation force within injectable platelet-rich-fibrin (PRF) concentrates advances patients' own inflammatory cells, platelets and growth factors: the first introduction to the low speed centrifugation concept.

Science.gov (United States)

Choukroun, J; Ghanaati, S

2018-02-01

The aim of this study was to analyze systematically the influence of the relative centrifugation force (RCF) on leukocytes, platelets and growth factor release within fluid platelet-rich fibrin matrices (PRF). Systematically using peripheral blood from six healthy volunteers, the RCF was reduced four times for each of the three experimental protocols (I-III) within the spectrum (710-44 g), while maintaining a constant centrifugation time. Flow cytometry was applied to determine the platelets and leukocyte number. The growth factor concentration was quantified 1 and 24 h after clotting using ELISA. Reducing RCF in accordance with protocol-II (177 g) led to a significantly higher platelets and leukocytes numbers compared to protocol-I (710 g). Protocol-III (44 g) showed a highly significant increase of leukocytes and platelets number in comparison to -I and -II. The growth factors' concentration of VEGF and TGF-β1 was significantly higher in protocol-II compared to -I, whereas protocol-III exhibited significantly higher growth factor concentration compared to protocols-I and -II. These findings were observed among 1 and 24 h after clotting, as well as the accumulated growth factor concentration over 24 h. Based on the results, it has been demonstrated that it is possible to enrich PRF-based fluid matrices with leukocytes, platelets and growth factors by means of a single alteration of the centrifugation settings within the clinical routine. We postulate that the so-called low speed centrifugation concept (LSCC) selectively enriches leukocytes, platelets and growth factors within fluid PRF-based matrices. Further studies are needed to evaluate the effect of cell and growth factor enrichment on wound healing and tissue regeneration while comparing blood concentrates gained by high and low RCF.

From Research Assistant to Professional Research Assistance: Research Consulting as a Form of Research Practice

Directory of Open Access Journals (Sweden)

Dawn E. Pollon

2013-01-01

Full Text Available Research assistantships have long been viewed as an extension of the formal education process, a form of apprenticeship, and a pathway into the professional practice of research in institutional settings. However, there are other contexts in which researchers practice research. This self-study documents the formative role research assistantships played in the authors’ development as professional research consultants. Four professional research consultants who held research assistant positions during their master’s and doctoral studies describe the contributions of their research assistantship experiences to the advancement of their knowledge, skills, and passion for research and subsequently to their career decisions. Professional research consulting is identified as a natural extension of research assistant roles and a potential career path. The article enhances current understandings about the ways research assistantships contribute to the development of researchers, and specifically to the development of professional research consultants. The analysis will be of interest to students contemplating entering into research assistantships, current research assistants, current research assistant supervisors, academic staff looking to improve their research productivity, and department chairs.

Ignition of a lean PRF/air mixture under RCCI/SCCI conditions: Chemical aspects

KAUST Repository

Luong, Minh Bau

2016-10-10

Chemical aspects of the ignition of a primary reference fuel (PRF)/air mixture under reactivity controlled compression ignition (RCCI) and stratified charge compression ignition (SCCI) conditions are investigated by analyzing two-dimensional direct numerical simulation (DNS) data with chemical explosive mode (CEM) analysis. CEMA is adopted to provide fundamental insights into the ignition process by identifying controlling species and elementary reactions at different locations and times. It is found that at the first ignition delay, low-temperature chemistry (LTC) represented by the isomerization of alkylperoxy radical, chain branching reactions of keto-hydroperoxide, and H-atom abstraction of n-heptane is predominant for both RCCI and SCCI combustion. In addition, explosion index and participation index analyses together with conditional means on temperature verify that low-temperature heat release (LTHR) from local mixtures with relatively-high n-heptane concentration occurs more intensively in RCCI combustion than in SCCI combustion, which ultimately advances the overall RCCI combustion and distributes its heat release rate over time. It is also found that at the onset of the main combustion, high-temperature heat release (HTHR) occurs primarily in thin deflagrations where temperature, CO, and OH are found to be the most important species for the combustion. The conversion reaction of CO to CO and hydrogen chemistry are identified as important reactions for HTHR. The overall RCCI/SCCI combustion can be understood by mapping the variation of 2-D RCCI/SCCI combustion in temperature space onto the temporal evolution of 0-D ignition.

Osteogenic Ability of Combined Hematopoetic Stem Cell, Hydroxyapatite Graft and Platelet Rich Fibrin on Rats (Rattus Novergicus

Directory of Open Access Journals (Sweden)

Dwi Rahmawati

2017-10-01

Full Text Available Background: In Indonesia, the incidence rate of tooth extraction as the main form of dental treatment reached as high as 79.6% in 2014. Teeth extraction leads to periodontal tissue defect whose treatment, incorporating the use of graft material Hydroxyapatite (HA and Platelet Rich Fibrin (PRF with stem cells, has become increasingly widespread. The stem cell potentially put to therapeutic use is the Hematopoetic Stem Cell (HSC. Aim and Objectives: to examine the effect of hematopoetic stem cell addition to HA graft and PRF post-tooth extraction on the number of osteoblasts and amount of Osteoprotegerin (OPG in periodontal defect treatment. Material and Methods: This study constituted laboratory-based experimental research with a post test-only control group. Twenty four rats (Rattus novergicus represented the animal study model in this research. Alveolar bone defect in the animal study model was induced by extracting the first molar of the mandible using sterile needle holder clamps. The sample population was divided into four groups: K0: the untreated control group; K1: socket filled with HA Graft and PRF. K2: socket filled with HSC 105 cells. K3: the socket filled with HA Graft and PRF with HSC 106 cells. Results: The K3 group had both the highest number of osteoblasts when compared with the control group (350.17 ± 33.42; P <0.001 and the strongest OPG expression of all treatment groups (11.36 ± 0.54; P <0.01. Conclusion: A combination of HA graft, PRF and HSC significantly increases the expression of OPG and the number of osteoblasts rendering it a potential treatment for tissue engineering-based periodontal defect.

The not-for-profit form and translational research: Kerr revisited?

Directory of Open Access Journals (Sweden)

Joiner Keith A

2005-04-01

Full Text Available Abstract Translational research conducted in academic health centers is confounded by the organizational structure in which the work is performed. Investigators must obtain research funding and appropriate recognition as a part of a research team in a not-for-profit environment which has more readily rewarded basic work, and individual accomplishments. What results is a unique form of conflict of interest, best understood by relating the basic principles underlying the not-for-profit form to the conduct of translational research in the AHC setting.

Assessing usefulness and researcher satisfaction with consent form templates.

Science.gov (United States)

Larson, Elaine L; Teller, Alan; Aguirre, Alejandra N; Jackson, Jhia; Meyer, Dodi

2017-08-01

We aimed to improve the research consenting process by developing and evaluating simplified consent forms. Four templates written at the eighth-tenth grade reading level were developed and trialed by a group of experts in clinical research, health literacy, national regulatory requirements, and end users. Researchers from protocols which had received expedited review were surveyed at 2 time points regarding their use and assessment of the templates. At baseline 18/86 (20.9%) responding researchers had heard of the templates and 5 (5.8%) reported that they had used them; 2 years later, 54.2% (32/59) had heard of the templates and 87.5% (28/32) had used them ( p Consent form templates may be one mechanism to improve patient comprehension of research protocols as well as efficiency of the review process, but require considerable time for development and implementation, and one key to their success is involvement and support from the IRB and technical staff.

Research Timeline: Form-Focused Instruction and Second Language Acquisition

Science.gov (United States)

Nassaji, Hossein

2016-01-01

This article provides a timeline of research on form-focused instruction (FFI). Over the past 40 years, research on the role of instruction has undergone many changes. Much of the early research concentrated on determining whether formal instruction makes any difference in the development of learner language. This question was motivated in part by…

Overview of superplastic forming research at ford motor company

Science.gov (United States)

Friedman, P. A.; Luckey, S. G.; Copple, W. B.; Allor, R.; Miller, C. E.; Young, C.

2004-12-01

In an effort to reduce vehicle weight, the automotive industry has switched to aluminum sheet for many closure panels. Although the application of aluminum is compatible with existing manufacturing processes and has attractive qualities such as low density, good mechanical properties, and high corrosion resistance, it has less room-temperature formability than steel. The expanded forming limits that are possible with superplastic forming can significantly improve the ability to manufacture complex shapes from materials with limited formability. Aluminum closure panels produced by superplastic forming have been used by Ford Motor Company for over a decade. However, applications have been limited to low-volume, specialty vehicles due to the relatively slow cycle time and the cost penalty associated with the specially processed sheet alloys. While there has been substantial research on the superplastic characteristics of aluminum alloys, the bulk of this work has focused on the development of aerospace alloys, which are often too costly and perhaps inappropriate for automotive applications. Additionally, there has been a limited amount of work done to develop the technologies required to support the higher production volumes of the automotive industry. This work presents an automotive perspective on superplastic forming and an overview of the research being performed at Ford Motor Company to increase the production volume so superplastic forming can be cost competitive with more traditional forming technologies.

48 CFR 46.309 - Research and development contracts (short form).

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Research and development... REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 46.309 Research and development contracts... Development (Short Form), in solicitations and contracts for research and development when the clause...

48 CFR 52.246-9 - Inspection of Research and Development (Short Form).

Science.gov (United States)

2010-10-01

... Clauses 52.246-9 Inspection of Research and Development (Short Form). As prescribed in 46.309, insert the following clause: Inspection of Research and Development (Short Form) (APR 1984) The Government has the... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Inspection of Research and...

Forms of interdisciplinarity in four sport science research centres in Europe.

Science.gov (United States)

Camy, Jean; Fargier, Patrick; Perrin, Claire; Belli, Alain

2017-02-01

Interdisciplinarity is often presented as a significant element of sport science. We present here the results of an investigation conducted in four European Sport Science Research Centres applying interdisciplinarity. Four main dimensions, that we have called "forms", have been investigated. The "scientific", "organisational", "academic" and "societal" forms cover a wide range of activities run by these Centres. We have compared their situations using indicators. Globally they present quite similar combinations of forms, with dominant roles in the construction of interdisciplinarity played by the organisational and societal forms. The scientific form is never quite supported by an epistemological setting and the academic form, mostly characterised by the position of the university, plays an influential role when it is hostile to that kind of research. Following Klein classification, all of them remain at a multidisciplinary stage, one of them exploring interdisciplinary tracks in some research projects. The development of a common culture and a curiosity regarding disciplines other than its own is a key factor for a sustainable situation, as is the capacity to secure long-term financial resources, often linked to a high academic recognition for the director(s).

Reading Level and Comprehension of Research Consent Forms: An Integrative Review.

Science.gov (United States)

Foe, Gabriella; Larson, Elaine L

2016-02-01

Consent forms continue to be at a higher reading level than the recommended sixth to eighth grade, making it difficult for participants to comprehend information before enrolling in research. To assess and address the extent of the problem regarding the level of literacy of consent forms and update previously published reports, we conducted an integrative literature review of English language research published between January 1, 2000, and December 31, 2013; 35 descriptive and eight intervention studies met inclusion criteria. Results confirmed that developing forms at eighth-grade level was attainable though not practiced. It was found that risks of participation was the section most poorly understood. There was also a lack of consensus regarding the most effective method to increase comprehension. Further research using standardized tools is needed to determine the best approach for improving consent forms and processes. © The Author(s) 2016.

Microbicidal properties of Leukocyte- and Platelet-Rich Plasma/Fibrin (L-PRP/L-PRF): new perspectives.

Science.gov (United States)

Cieslik-Bielecka, A; Dohan Ehrenfest, D M; Lubkowska, A; Bielecki, T

2012-01-01

Platelets, as main actors of the first stage of the healing process, play an important role in tissue repair. Their granules contain many active substances, particularly over 30 growth factors with significant effects on the resident cells at the site of injury, such as mesenchymal stem cells, chondrocytes, fibroblasts, osteoblasts. This potential may be increased by the concentration of the platelets, using platelet-rich plasma/fibrin products. In the four families of platelet concentrates, 2 families contain also significant concentrations of leukocytes: L-PRP (Leukocyte- and Platelet-Rich Plasma) and L-PRF (Leukocyte- and Platelet-Rich Fibrin). Inductive properties of platelet concentrates were widely described. However, they present also antimicrobial effects. The antibacterial effects of L-PRP were highlighted in only a few in vitro studies. Strong activity comparable to gentamicin and oxacillin for L-PRP against methicillin susceptible Staphylococcus aureus (MSSA) was already demonstrated. L-PRP also inhibited the growth of methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli. Some authors also reported clinical observations about the reduction of infections and the induction of healing processes after the use of platelet concentrates in cardiac, orthopaedic, oral and maxillofacial surgery. However, very little is yet known about the antibacterial effects of these concentrates. In this manuscript, the current data about the antimicrobial agents and cells present in the platelet-rich plasma/fibrin are highlighted and discussed, in order to introduce this new key chapter of the platelet concentrate technology history.

The chitinolytic activity of Listeria monocytogenes EGD is regulated by carbohydrates but also by the virulence regulator PrfA

DEFF Research Database (Denmark)

Larsen, Marianne Halberg; Leisner, Jørgen; Ingmer, Hanne

2010-01-01

Chitin, an insoluble polymer of N-acetyl-D-glucosamine (GlcNAc), is one of the most abundant carbohydrate polymers in marine and terrestrial environments. Chitin hydrolysis by Listeria monocytogenes depends on two chitinase-encoding genes, chiA and chiB, and the aim of this study was to investigate...... their regulation. Chitin induces the expression of both chitinases in late exponential growth phase, and chiA but not chiB is furthermore induced by the monomer GlcNAc. Furthermore, their expression is subjected to catabolite control. Chitinases expressed by bacterial pathogens have proven to be important not only...... in wild-type cells. In agreement with this, Northern blot analysis showed that the amounts of chiA and chiB transcripts upon induction by chitin were significantly lower in the prfA mutant than in the wild type. The chitinolytic activity and chiA and chiB expression were reduced in the absence of the sig...

Design and Certification of Targets for Drop Tests at the NTRC Packaging Research Facility

International Nuclear Information System (INIS)

Ludwig, S.B.

2003-01-01

This report provides documentation of the design and certification of drop pad (targets) at the National Transportation Research Center (NTRC) Packaging Research Facility(PRF). Based on the evaluation performed, it has been demonstrated that the small (interior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 3,150 lb (1,432 kg). The large (exterior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 28,184 lb (12,811 kg)

Evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin.

Science.gov (United States)

Baslarli, Ozgur; Tumer, Celal; Ugur, Omer; Vatankulu, Betul

2015-01-01

The aim of this study was to determine whether the use of platelet rich fibrin (PRF) improved the healing of extraction sockets. A total of 20 patients with bilateral soft tissue impacted mandibular third molars were included in this study. The left and right third molars were extracted during the same session. Subsequently, the PRF membrane was randomly administered to one of the extraction sockets, whereas the contralateral sockets were left without treatment. On postoperative 30. and 90. days, panoramic images and bone scintigrams were taken to evaluate the bone healing between PRF-treated and non-PRF-treated sockets. Also, periodontal evaluation was performed in the same control sessions. Dependent group t test for paired samples was used for statistical analysis. The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 30 and 90 days postoperatively. Radio-opacity that can show the bone healing on panoramic images were measured by Image J programme and they did not differ significantly. Also periodontal values did not differ significantly. PRF might not lead to enhanced bone healing in impacted mandibular third molar extraction sockets 30 and 90 days after surgery. It is thought that PRF has the potential characteristics of an autologous fibrin matrix and can accelerate the healing. To better understand the effects of PRF on healing, further research is warranted with larger sample sizes.

Listeria-vectored vaccine expressing the Mycobacterium tuberculosis 30 kDa major secretory protein via the constitutively active prfA* regulon boosts BCG efficacy against tuberculosis.

Science.gov (United States)

Jia, Qingmei; Dillon, Barbara Jane; Masleša-Galić, Saša; Horwitz, Marcus A

2017-06-19

A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis (Mtb) 30 kDa major secretory protein (r30/Ag85B) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated Lm vectors, rLm Δ actA (LmI), rLm Δ actA Δ inlB (LmII), and rLm Δ actA Δ inlB prfA * (LmIII), we constructed five rLm30 vaccine candidates expressing the r30 linked in-frame to the Lm Listeriolycin O signal sequence and driven by the hly promoter (h30) or linked in-frame to the ActA N-terminus and driven by the actA promoter (a30). All five rLm30 vaccines secreted r30 in broth and macrophages; while rLm expressing r30 via a constitutively active prfA * regulon (rLmIII/a30) expressed the greatest amount of r30 in broth culture, all five rLm vaccines expressed equivalent amounts of r30 in infected macrophages. In comparative studies, boosting BCG-immunized mice with rLmIII/a30 induced the strongest antigen-specific T-cell responses, including splenic and lung polyfunctional CD4+ T-cells expressing the three cytokines of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) ( P vaccines were generally more potent booster vaccines than r30 in adjuvant and a recombinant adenovirus vaccine expressing r30. In a setting in which BCG alone was highly immunoprotective, boosting mice with rLmIII/a30, the most potent of the vaccines, significantly enhanced protection against aerosolized Mtb ( P <0.01). Copyright © 2017 American Society for Microbiology.

Reflective functioning, physiological reactivity, and overcontrol in mothers: Links with school-aged children's reflective functioning.

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Borelli, Jessica L; Hong, Kajung; Rasmussen, Hannah F; Smiley, Patricia A

2017-09-01

Theorists argue that parental reflective functioning (PRF) is activated in response to emotions, potentially supporting parenting sensitivity even when arousal is high. That is, when parents become emotionally reactive when interacting with their children, those who can use PRF to understand their children's mental states should be able to parent sensitively, which, in turn, should promote children's ability to understand their own mental states. We test this theory by examining whether, in the face of physiological reactivity, mothers' PRF inhibits one form of parenting insensitivity, overcontrol (OC), and whether this process in turn predicts children's RF. A diverse sample of school-age children (N = 106, Mage = 10.27 years) completed a standardized failure paradigm while their mothers were asked to passively observe. Following the stressor, mothers and children independently completed interviews regarding the task, which were later coded for RF with respect to children's mental states. Mothers provided saliva samples before and after the stressor, and after the interview, which were later assayed for cortisol reactivity; maternal behavior during the stressor task was coded for OC. Among mothers with low levels of RF, greater increases in cortisol were associated with more displays of OC, whereas among mothers with high PRF, greater cortisol reactivity was associated with fewer OC behaviors. For low PRF mothers, higher reactivity and OC predicted lower children's PRF for their own experiences. The findings provide initial evidence for a protective function of PRF, and may point toward the importance of promoting PRF in intervention programs to reduce parental OC. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effects of leukocyte-platelet rich fibrin on postoperative complications of direct sinus lifting.

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Gurler, Gokhan; Delilbasi, Cagri

2016-08-01

Blood products have been widely used in soft tissue and bone regeneration in oral and maxillofacial surgery. The purpose of this study is to evaluate the effects of leukocyte-platelet rich fibrin (L-PRF) following direct sinus lifting procedure. Twenty-eight patients were included in the study. Direct sinus lifting was performed via lateral window approach under conscious sedation and local anesthesia. Bony window and sinus floor elevation were performed using piezosurgery device. Two groups were formed. In the first group an allogenous bone graft and L-PRF mixture was used as grafting material. The L-PRF membrane was used to close the lateral window. In the second group, only allogenous bone was used for grafting and resorbable collagen membrane was used to close the lateral window. Pain, swelling, sleeping, eating, phonetics, activities of daily living, missed work days and soft tissue healing were evaluated postoperatively. Data of 24 patients were evaluated. Improvements were seen in the studied parameters in the L-PRF group; however, the difference was not significant between the two groups (P>0.05). The use of L-PRF and allogenous bone graft in combination with L-PRF membrane does not significantly improve postoperative complications following direct sinus lifting.

Ethics in clinical research: need for assessing comprehension of informed consent form?

Science.gov (United States)

Shafiq, Nusrat; Malhotra, Samir

2011-03-01

Comprehension of informed consent form has not achieved the attention it deserves. We made a 24-item questionnaire to assess clinical research participants' comprehension of informed consent form (Contemp Clin Trials 2009;30:427-30). Due to repeated requests by clinical researchers in our country and abroad, we are publishing the questionnaire in this article. Copyright © 2010 Elsevier Inc. All rights reserved.

Potential dental pulp revascularization and odonto-/osteogenic capacity of a novel transplant combined with dental pulp stem cells and platelet-rich fibrin.

Science.gov (United States)

Chen, Yong-Jin; Zhao, Yin-Hua; Zhao, Ya-Juan; Liu, Nan-Xia; Lv, Xin; Li, Qiang; Chen, Fa-Ming; Zhang, Min

2015-08-01

Our aim is to investigate the cytobiological effects of autologous platelet-rich fibrin (PRF) on dental pulp stem cells (DPSCs) and to explore the ectopic and orthotopic possibilities of dental pulp revascularization and pulp-dentin complex regeneration along the root canal cavities of the tooth by using a novel tissue-engineered transplant composed of cell-sheet fragments of DPSCs and PRF granules. Canine DPSCs were isolated and characterized by assaying their colony-forming ability and by determining their cell surface markers and osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF on DPSCs, including cell proliferation, alkaline phosphatase (ALP) activity and odonto-/osteogenic gene expression, were then investigated and quantified. A novel transplant consisting of cell-sheet fragments of DPSCs and PRF granules was adopted to regenerate pulp-dentin-like tissues in the root canal, both subcutaneously in nude mice and in the roots of canines. PRF promoted the proliferation of DPSCs in a dose- and time-dependent manner and induced the differentiation of DPSCs to odonto-/osteoblastic fates by increasing the expression of the Alp, Dspp, Dmp1 and Bsp genes. Transplantation of the DPSC/PRF construct led both to a favorable regeneration of homogeneous and compact pulp-like tissues with abundantly distributed blood capillaries and to the deposition of regenerated dentin along the intracanal walls at 8 weeks post-operation. Thus, the application of DPSC/PRF tissue constructs might serve as a potential therapy in regenerative endodontics for pulp revitalization or revascularization.

Three-dimensional architecture and cell composition of a Choukroun's platelet-rich fibrin clot and membrane.

Science.gov (United States)

Dohan Ehrenfest, David M; Del Corso, Marco; Diss, Antoine; Mouhyi, Jaafar; Charrier, Jean-Baptiste

2010-04-01

Platelet-rich fibrin (PRF; Choukroun's technique) is a second-generation platelet concentrate for surgical use. This easy protocol allows the production of leukocyte and platelet-rich fibrin clots and membranes starting from 10-ml blood samples. The purposes of this study were to determine the cell composition and three-dimensional organization of this autologous biomaterial and to evaluate the influence of different collection tubes (dry glass or glass-coated plastic tubes) and compression procedures (forcible or soft) on the final PRF-membrane architecture. After centrifugation, blood analyses were performed on the residual waste plasmatic layers after collecting PRF clots. The PRF clots and membranes were processed for examination by light microscopy and scanning electron microscopy. Approximately 97% of the platelets and >50% of the leukocytes were concentrated in the PRF clot and showed a specific three-dimensional distribution, depending on the centrifugation forces. Platelets and fibrin formed large clusters of coagulation in the first millimeters of the membrane beyond the red blood cell base. The fibrin network was very mature and dense. Moreover, there was no significant difference in the PRF architecture between groups using the different tested collection tubes and compression techniques, even if these two parameters could have influenced the growth factor content and biologic matrix properties. The PRF protocol concentrated most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. This protocol offers reproducible results as long as the main production principles are respected.

Spontaneous Loss of Virulence in Natural Populations of Listeria monocytogenes.

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Maury, Mylène M; Chenal-Francisque, Viviane; Bracq-Dieye, Hélène; Han, Lei; Leclercq, Alexandre; Vales, Guillaume; Moura, Alexandra; Gouin, Edith; Scortti, Mariela; Disson, Olivier; Vázquez-Boland, José A; Lecuit, Marc

2017-11-01

The pathogenesis of Listeria monocytogenes depends on the ability of this bacterium to escape from the phagosome of the host cells via the action of the pore-forming toxin listeriolysin O (LLO). Expression of the LLO-encoding gene ( hly ) requires the transcriptional activator PrfA, and both hly and prfA genes are essential for L. monocytogenes virulence. Here, we used the hemolytic activity of LLO as a phenotypic marker to screen for spontaneous virulence-attenuating mutations in L. monocytogenes Sixty nonhemolytic isolates were identified among a collection of 57,820 confirmed L. monocytogenes strains isolated from a variety of sources (0.1%). In most cases (56/60; 93.3%), the nonhemolytic phenotype resulted from nonsense, missense, or frameshift mutations in prfA Five strains carried hly mutations leading to a single amino acid substitution (G299V) or a premature stop codon causing strong virulence attenuation in mice. In one strain, both hly and gshF (encoding a glutathione synthase required for full PrfA activity) were missing due to genomic rearrangements likely caused by a transposable element. The PrfA/LLO loss-of-function (PrfA - /LLO - ) mutants belonged to phylogenetically diverse clades of L. monocytogenes , and most were identified among nonclinical strains (57/60). Consistent with the rare occurrence of loss-of-virulence mutations, we show that prfA and hly are under purifying selection. Although occurring at a low frequency, PrfA - /LLO - mutational events in L. monocytogenes lead to niche restriction and open an evolutionary path for obligate saprophytism in this facultative intracellular pathogen. Copyright © 2017 Maury et al.

Reading Level and Length of Written Research Consent Forms

Science.gov (United States)

Foe, Gabriella; Lally, Rachel

2015-01-01

Abstract In 100 Institutional Review Board approved consent forms (CFs), we assessed pages, reading levels, and whether they included essential elements. CF page numbers ranged from 3 to 28 (mean, 10.3) and readability ranged from grades 5.6 to 28.9 (mean, 11.6). The CF mean score for including essential elements was 90.8% (range: 63.5–100%). There were no significant differences by specialty in number of pages (p = 0.053), but surgical specialties had the highest readability (mean, 13.1), and pediatrics the lowest (10.5), p = 0.008. While approved CFs generally included the Office for Human Research Protections recommended essential elements, they were very long, and even pediatric forms, which had the lowest reading levels, were written on average at a tenth grade level. Researchers need guidance to resolve pressure between regulatory mandates and guidelines and “keeping it simple and clear.” PMID:25580939

Separations and Waste Forms Research and Development FY 2013 Accomplishments Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2013-12-01

The Separations and Waste Form Campaign (SWFC) under the U.S. Department of Energy (DOE) Fuel Cycle Research and Development Program (FCRD) is responsible for developing advanced separation and waste form technologies to support the various fuel cycle options defined in the DOE Nuclear Energy Research and Development Roadmap, Report to Congress, April 2010. The fiscal year (FY) 2013 accomplishments report provides a highlight of the results of the research and development (R&D) efforts performed within SWFC in FY 2013. Each section contains a high-level overview of the activities, results, technical point of contact, applicable references, and documents produced during the fiscal year. This report briefly outlines campaign management and integration activities, but the intent of the report is to highlight the many technical accomplishments made during FY 2013.

Exploring Forms of Triangulation to Facilitate Collaborative Research Practice: Reflections From a Multidisciplinary Research Group

Directory of Open Access Journals (Sweden)

Tarja Tiainen

2006-10-01

Full Text Available This article contains critical reflections of a multidisciplinary research group studying the human and technological dynamics around some newly offered electronic services in a specific rural area of Finland. For their research, the group adopted ethnography. On facing the challenges of doing ethnographic research in a multidisciplinary setting, the group evolved its own breed of research practice based on multiple forms of triangulation. This implied the use of multiple data sources, methods, theories, and researchers, in different combinations. One of the outcomes of the work is a model for collaborative research. It highlights, among others, the importance of creating a climate for collaboration within the research group and following a process of individual and collaborative writing to achieve the potential benefits of such research. The article also identifies a set of remaining challenges relevant to collaborative research.

How novice, skilled and advanced clinical researchers include variables in a case report form for clinical research: a qualitative study.

Science.gov (United States)

Chu, Hongling; Zeng, Lin; Fetters, Micheal D; Li, Nan; Tao, Liyuan; Shi, Yanyan; Zhang, Hua; Wang, Xiaoxiao; Li, Fengwei; Zhao, Yiming

2017-09-18

Despite varying degrees in research training, most academic clinicians are expected to conduct clinical research. The objective of this research was to understand how clinical researchers of different skill levels include variables in a case report form for their clinical research. The setting for this research was a major academic institution in Beijing, China. The target population was clinical researchers with three levels of experience, namely, limited clinical research experience, clinicians with rich clinical research experience and clinical research experts. Using a qualitative approach, we conducted 13 individual interviews (face to face) and one group interview (n=4) with clinical researchers from June to September 2016. Based on maximum variation sampling to identify researchers with three levels of research experience: eight clinicians with limited clinical research experience, five clinicians with rich clinical research experience and four clinical research experts. These 17 researchers had diverse hospital-based medical specialties and or specialisation in clinical research. Our analysis yields a typology of three processes developing a case report form that varies according to research experience level. Novice clinician researchers often have an incomplete protocol or none at all, and conduct data collection and publication based on a general framework. Experienced clinician researchers include variables in the case report form based on previous experience with attention to including domains or items at risk for omission and by eliminating unnecessary variables. Expert researchers consider comprehensively in advance data collection and implementation needs and plan accordingly. These results illustrate increasing levels of sophistication in research planning that increase sophistication in selection for variables in the case report form. These findings suggest that novice and intermediate-level researchers could benefit by emulating the comprehensive

Bipolar High-Voltage, Long-Duration Pulsed Radiofrequency Improves Pain Relief in Postherpetic Neuralgia.

Science.gov (United States)

Wan, Cheng-Fu; Liu, Yan; Dong, Dao-Song; Zhao, Lin; Xi, Qi; Yu, Xue; Cui, Wen-Yao; Wang, Qiu-Shi; Song, Tao

2016-07-01

Postherpetic neuralgia (PHN) is often refractory to existing treatments. Treatment of the dorsal root ganglion (DRG) using monopolar pulsed radiofrequency (PRF), which is a non- or minimally neurodestructive technique, is not efficacious in all patients. This study aimed to determine the safety and clinical efficacy of bipolar high-voltage, long-duration PRF on the DRG in PHN patients. Self before-after controlled clinical trial. Department of Pain Medicine, the First Affiliated Hospital of China Medical University. Ninety patients diagnosed with PHN for > 3months were included. Bipolar high-voltage, long-duration PRF at 42°C for 900 seconds was applied after the induction of paresthesias covered the regions of hyperalgesic skin. The therapeutic effects were evaluated using a visual analog scale (VAS) and the 36-item Short Form health survey (SF-36) before treatment and one, 4, 8, and 12 weeks after PRF. The VAS scores at one, 4, 8, and 12 weeks after PRF treatment were significantly lower than before treatment (P DRG is an effective and safe therapeutic alternative for PHN patients. This treatment could improve the quality of life of PHN patients. NO ChiCTR-OCS-14005461.

News at Biochemia Medica: research integrity corner, updated guidelines to authors, revised author statement form and adopted ICMJE Conflict-of-Interest Form.

Science.gov (United States)

Simundic, Ana-Maria

2013-01-01

From the issue 23(1) we have implemented several major changes in the editorial policies and procedures. We hope that those changes will raise awareness of our potential authors and reviewers for research and publication integrity issues as well as to improve the quality of our submissions and published articles. Among those changes is the launch of a special journal section called Research Integrity Corner. In this section we aim to publish educational articles dealing with different research and publication misconduct issues. Moreover, we have done a comprehensive revision of our Instructions to authors. Whereas our former Instructions to authors have mostly been concerned with recommendations for manuscript preparation and submission, the revised document additionally describes the editorial procedure for all submitted articles and provides exact journal policies towards research integrity, authorship, copyright and conflict of interest. By putting these Guidelines into action, we hope that our main ethical policies and requirements are now visible and available to all our potential authors. We have also revised the former Authorship and copyright form which is now called the Author statement form. This form now contains statements on the authorship, originality of work, research ethics, patient privacy and confidentiality, and copyright transfer. Finally, Journal has adopted the ICMJE Form for Disclosure of Potential Conflicts of Interest. From this issue, for each submitted article, authors are requested to fill out the "ICMJE Form for Disclosure of Potential Conflicts of Interest" as well as the Author statement form and upload those forms during the online manuscript submission process. We honestly believe that our authors and readers will appreciate such endeavors. In this Editorial article we briefly explain the background and the nature of those recent major editorial changes.

Emerging issues in paediatric health research consent forms in Canada: working towards best practices.

Science.gov (United States)

Dove, Edward S; Avard, Denise; Black, Lee; Knoppers, Bartha M

2013-01-30

Obtaining a research participant's voluntary and informed consent is the bedrock of sound ethics practice. Greater inclusion of children in research has led to questions about how paediatric consent operates in practice to accord with current and emerging legal and socio-ethical issues, norms, and requirements. Employing a qualitative thematic content analysis, we examined paediatric consent forms from major academic centres and public organisations across Canada dated from 2008-2011, which were purposively selected to reflect different types of research ethics boards, participants, and studies. The studies included biobanking, longitudinal studies, and gene-environment studies. Our purpose was to explore the following six emerging issues: (1) whether the scope of parental consent allows for a child's assent, dissent, or future consent; (2) whether the concepts of risk and benefit incorporate the child's psychological and social perspective; (3) whether a child's ability to withdraw is respected and to what extent withdrawal is permitted; (4) whether the return of research results includes individual results and/or incidental findings and the processes involved therein; (5) whether privacy and confidentiality concerns adequately address the child's perspective and whether standard data and/or sample identifiability nomenclature is used; and (6) whether retention of and access to paediatric biological samples and associated medical data are addressed. The review suggests gaps and variability in the consent forms with respect to addressing each of the six issues. Many forms did not discuss the possibility of returning research results, be they individual or general/aggregate results. Forms were also divided in terms of the scope of parental consent (specific versus broad), and none discussed a process for resolving disputes that can arise when either the parents or the child wishes to withdraw from the study. The analysis provides valuable insight and evidence into

Emerging issues in paediatric health research consent forms in Canada: working towards best practices

Directory of Open Access Journals (Sweden)

Dove Edward S

2013-01-01

Full Text Available Abstract Background Obtaining a research participant’s voluntary and informed consent is the bedrock of sound ethics practice. Greater inclusion of children in research has led to questions about how paediatric consent operates in practice to accord with current and emerging legal and socio-ethical issues, norms, and requirements. Methods Employing a qualitative thematic content analysis, we examined paediatric consent forms from major academic centres and public organisations across Canada dated from 2008–2011, which were purposively selected to reflect different types of research ethics boards, participants, and studies. The studies included biobanking, longitudinal studies, and gene-environment studies. Our purpose was to explore the following six emerging issues: (1 whether the scope of parental consent allows for a child’s assent, dissent, or future consent; (2 whether the concepts of risk and benefit incorporate the child’s psychological and social perspective; (3 whether a child’s ability to withdraw is respected and to what extent withdrawal is permitted; (4 whether the return of research results includes individual results and/or incidental findings and the processes involved therein; (5 whether privacy and confidentiality concerns adequately address the child’s perspective and whether standard data and/or sample identifiability nomenclature is used; and (6 whether retention of and access to paediatric biological samples and associated medical data are addressed. Results The review suggests gaps and variability in the consent forms with respect to addressing each of the six issues. Many forms did not discuss the possibility of returning research results, be they individual or general/aggregate results. Forms were also divided in terms of the scope of parental consent (specific versus broad, and none discussed a process for resolving disputes that can arise when either the parents or the child wishes to withdraw from the

Proposed research and development plan for mixed low-level waste forms

Energy Technology Data Exchange (ETDEWEB)

O`Holleran, T.O.; Feng, X.; Kalb, P. [and others

1996-12-01

The objective of this report is to recommend a waste form program plan that addresses waste form issues for mixed low-level waste (MLLW). The report compares the suitability of proposed waste forms for immobilizing MLLW in preparation for permanent near-surface disposal and relates them to their impact on the U.S. Department of Energy`s mixed waste mission. Waste forms are classified into four categories: high-temperature waste forms, hydraulic cements, encapsulants, and specialty waste forms. Waste forms are evaluated concerning their ability to immobilize MLLW under certain test conditions established by regulatory agencies and research institutions. The tests focused mainly on leach rate and compressive strength. Results indicate that all of the waste forms considered can be tailored to give satisfactory performance immobilizing large fractions of the Department`s MLLW inventory. Final waste form selection will ultimately be determined by the interaction of other, often nontechnical factors, such as economics and politics. As a result of this report, three top-level programmatic needs have been identified: (1) a basic set of requirements for waste package performance and disposal; (2) standardized tests for determining waste form performance and suitability for disposal; and (3) engineering experience operating production-scale treatment and disposal systems for MLLW.

Proposed research and development plan for mixed low-level waste forms

International Nuclear Information System (INIS)

O'Holleran, T.O.; Feng, X.; Kalb, P.

1996-12-01

The objective of this report is to recommend a waste form program plan that addresses waste form issues for mixed low-level waste (MLLW). The report compares the suitability of proposed waste forms for immobilizing MLLW in preparation for permanent near-surface disposal and relates them to their impact on the U.S. Department of Energy's mixed waste mission. Waste forms are classified into four categories: high-temperature waste forms, hydraulic cements, encapsulants, and specialty waste forms. Waste forms are evaluated concerning their ability to immobilize MLLW under certain test conditions established by regulatory agencies and research institutions. The tests focused mainly on leach rate and compressive strength. Results indicate that all of the waste forms considered can be tailored to give satisfactory performance immobilizing large fractions of the Department's MLLW inventory. Final waste form selection will ultimately be determined by the interaction of other, often nontechnical factors, such as economics and politics. As a result of this report, three top-level programmatic needs have been identified: (1) a basic set of requirements for waste package performance and disposal; (2) standardized tests for determining waste form performance and suitability for disposal; and (3) engineering experience operating production-scale treatment and disposal systems for MLLW

Novel Forms of Research Governance and Their Possible Impact on the Future of Educational Research

Science.gov (United States)

Pataki, Gyöngyvér

2015-01-01

This article sets out to contribute to the current debate on the transformation of educational research with regard to global transitions and challenges. Nation-centred hierarchical organizations in Europe have increasingly failed to address emergent processes. And in contrast novel forms of governance have gained prevalence in controlling…

Evaluation of the Effect of Duration on the Efficacy of Pulsed Radiofrequency in an Animal Model of Neuropathic Pain.

Science.gov (United States)

Ramzy, Eiad A; Khalil, Khaled I; Nour, Eman M; Hamed, Mohammed F; Taha, Mohamed A

2018-03-01

Pulsed radiofrequency (PRF) is increasingly used in clinical practice, especially in neuropathic pain disorders. Although PRF is not new to clinical use, there are significant gaps in knowledge regarding its effectiveness. The current study was conducted to evaluate the effect of duration of application of PRF on its analgesic efficacy in improvement of neuropathic pain. A randomized experimental trial. An animal research facility at the College of Veterinary Medicine at Mansoura University in Egypt. Chronic constriction of the sciatic nerve of 36 male Sprague-Dawley rats was performed to induce neuropathic pain. The rats were divided into 6 groups (6 rats each) in which PRF was applied for 2, 4, 6, or 8 minutes or not at all. In one group, RF cannula was applied without performing PRF intervention. The pain was assessed through observation of resting paw posture (RPP) at 3, 10, and 21 days. Nerve damage was assessed by histopathological evaluation of the sciatic nerve. Immunohistochemical localization of proinflammatory cytokines (interleukin 6 [IL-6] and tumor necrosis factor alpha [TNF-alpha]) was also done. RPP was improved in rats treated with PRF. This improvement was significant only in rats treated for 8 minutes. Increased duration for PRF application was associated with a significant decrease in IL-6 and TNF-alpha contents in all groups when compared with the control group. Histopathological evaluation of the constricted sciatic nerve revealed no statistical significance among the different study groups. The study was limited by the lack of measurement of other inflammatory markers that may help elucidate other relevant mechanisms. Increased duration of PRF application resulted in better analgesic efficacy without any increase in tissue injury in an animal model of neuropathic pain. This effect may be attributed to decreased production of pro-inflammatory cytokines. Pulsed radiofrequency, analgesic, rats, sciatic nerve, duration, neuropathic pain.

A novel platelet concentrate: titanium-prepared platelet-rich fibrin.

Science.gov (United States)

Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Yaprak, Emre; Toker, Hülya; Fıratlı, Erhan

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

Directory of Open Access Journals (Sweden)

Mustafa Tunalı

2014-01-01

Full Text Available We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF. The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun’s leukocyte- and platelet-rich fibrin (L-PRF method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF was processed with a scanning electron microscope (SEM. The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

Research Status on the Heterogeneous Sheet Connection Forming Technology

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SHI Wen-yong

2017-04-01

Full Text Available The heterogeneous sheet connection forming is one of the effective ways to realize lightweight in many fields，such as equipment manufacturing and transportation. However, there are obvious differences in the material properties，when using the traditional connection methods，there is a certain technical bottlenecks. In this paper, the technological characteristics and research status of the welding method and mechanical connection method are discussed in detail，such as the TIC welding and the laser welding. The advantages and development potential of the technology are introduced in the field of the heterogeneous sheet connection，in combination with the industry development and the use demand，the development of the heterogeneous sheet connection technology is expected，to provide the technical support for the research and development of new heterogeneous sheet connection technology.

Potential for Osseous Regeneration of Platelet-Rich Fibrin-A Comparative Study in Mandibular Third Molar Impaction Sockets.

Science.gov (United States)

Varghese, Mathew P; Manuel, Suvy; Kumar L K, Surej

2017-07-01

This study investigated the potential of platelet-rich fibrin (PRF) for osseous regeneration and soft tissue healing in mandibular third molar impaction sockets. A prospective in vivo study was performed. Randomization was performed after extraction. On one side, the socket was sutured primarily (control site); on the other side, autologous PRF gel was placed and then the socket was sutured (test site). Postoperatively, grid periapical radiographs were obtained at periodic intervals (weeks 1, 4, and 16) and digitalized. Gray-level values were measured at 3 different regions of the socket (for regions of newly formed bone) compared with the natural bone area using HL Image++ software, and the percentage bone fill was measured. Clinical evaluation of soft tissue healing was performed using the healing index of Landry et al (J Periodontol 60:212, 1994) at the specific intervals. Thirty healthy men and women (age range, 18 to 35 yr) with bilaterally impacted mandibular third molars were enrolled in this study. In general, there was markedly greater bone formation in sockets treated with PRF (P < .05). In the PRF group, the average gray-level values at the cervical, middle, and apical regions were 61.85 (standard deviation [SD], ±25.186), 64.54 (SD, ±24.831), and 67.80 (SD, ±23.946), respectively, with a mean value of 64.73 (SD, ±24.411). In the control group, these values were 51.58 (SD, ±15.286), 54.30 (SD, ±16.274), and 57.53 (SD, ±16.187), respectively, with a mean of 53.67 (SD, ±16.528). The average percentage of bone fill in the PRF group was 57.90 (SD, ±26.789) and that of the non-PRF group was 46.74 (SD, ±17.713; P < .05). Soft tissue healing as evaluated by the healing index of Landry et al also was found to be better at the PRF test site and it was statistically significant (P < .05). There was evidence for better osseous regeneration and soft tissue healing in response to PRF. Further investigations to evaluate the application of PRF in other

A New Method to Develop Human Dental Pulp Cells and Platelet-rich Fibrin Complex.

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He, Xuan; Chen, Wen-Xia; Ban, Guifei; Wei, Wei; Zhou, Jun; Chen, Wen-Jin; Li, Xian-Yu

2016-11-01

Platelet-rich fibrin (PRF) has been used as a scaffold material in various tissue regeneration studies. In the previous methods to combine seed cells with PRF, the structure of PRF was damaged, and the manipulation time in vitro was also increased. The objective of this in vitro study was to explore an appropriate method to develop a PRF-human dental pulp cell (hDPC) complex to maintain PRF structure integrity and to find out the most efficient part of PRF. The PRF-hDPC complex was developed at 3 different time points during PRF preparation: (1) the before centrifugation (BC) group, the hDPC suspension was added to the venous blood before blood centrifugation; (2) the immediately after centrifugation (IAC) group, the hDPC suspension was added immediately after blood centrifugation; (3) the after centrifugation (AC) group, the hDPC suspension was added 10 minutes after blood centrifugation; and (4) the control group, PRF without hDPC suspension. The prepared PRF-hDPC complexes were cultured for 7 days. The samples were fixed for histologic, immunohistochemistry, and scanning electron microscopic evaluation. Real-time polymerase chain reaction was performed to evaluate messenger RNA expression of alkaline phosphatase and dentin sialophosphoprotein. Enzyme-linked immunosorbent assay quantification for growth factors was performed within the different parts of the PRF. Histologic, immunohistochemistry, and scanning electron microscopic results revealed that hDPCs were only found in the BC group and exhibited favorable proliferation. Real-time polymerase chain reaction revealed that alkaline phosphatase and dentin sialophosphoprotein expression increased in the cultured PRF-hDPC complex. The lower part of the PRF released the maximum quantity of growth factors. Our new method to develop a PRF-hDPCs complex maintained PRF structure integrity. The hDPCs were distributed in the buffy coat, which might be the most efficient part of PRF. Copyright © 2016 American

Two-dimensional Shear Wave Elastography on Conventional Ultrasound Scanners with Time Aligned Sequential Tracking (TAST) and Comb-push Ultrasound Shear Elastography (CUSE)

OpenAIRE

Song, Pengfei; Macdonald, Michael C.; Behler, Russell H.; Lanning, Justin D.; Wang, Michael H.; Urban, Matthew W.; Manduca, Armando; Zhao, Heng; Callstrom, Matthew R.; Alizad, Azra; Greenleaf, James F.; Chen, Shigao

2015-01-01

Two-dimensional (2D) shear wave elastography presents 2D quantitative shear elasticity maps of tissue, which are clinically useful for both focal lesion detection and diffuse disease diagnosis. Realization of 2D shear wave elastography on conventional ultrasound scanners, however, is challenging due to the low tracking pulse-repetition-frequency (PRF) of these systems. While some clinical and research platforms support software beamforming and plane wave imaging with high PRF, the majority of...

Scintigraphic evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin.

Science.gov (United States)

Gürbüzer, Bahadir; Pikdöken, Levent; Tunali, Mustafa; Urhan, Muammer; Küçükodaci, Zafer; Ercan, Feriha

2010-05-01

To evaluate the effect of platelet-rich fibrin (PRF) on the early bone healing process with bone scintigraphy based on technetium-99m methylene diphosphonate uptake in third molar extraction sockets. Fourteen patients with bilaterally soft tissue impacted third mandibular molars were included in the study. The right and left impacted third molars were surgically extracted in the same session. PRF was randomly administered into one of the extraction sockets, whereas the contralateral sockets were left without treatment. Four weeks after surgery, scintigrams were obtained to evaluate scintigraphic differences between PRF-treated and non-PRF-treated sockets. After completion of the clinical study, PRF samples were evaluated by light and scanning electron microscopy. The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 4 weeks postoperatively (P > .05). Abundant fibrin and inflammatory cells were observed by light microscopic examination of PRF samples. Scanning electron microscopic analysis of PRF revealed the existence of platelet aggregates in a fibrin network and crystalline particles on the outer surface of PRF. PRF might not lead to enhanced bone healing in soft tissue impacted mandibular third molar extraction sockets 4 weeks after surgery. PRF exhibits the potential characteristics of an autologous fibrin matrix. However, whether the presence of crystal-like particles on the outer surface of PRF alters bone healing should be investigated further. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Summary of INEL research on the iron-enriched basalt waste form

International Nuclear Information System (INIS)

Reimann, G.A.; Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

1992-01-01

This report summarizes the knowledge base on the iron-enriched basalt (IEB) waste form developed at the Idaho National Engineering Laboratory (INEL) during 1979--1982. The results presented discuss the applicability of IEB in converting retrieved transuranic (TRU) waste from INEL's Radioactive Waste Management Complex (RWMC) into a vitreous/ceramic (glassy/rock) stable waste form suitable for permanent disposal in an appropriate repository, such as the Waste Isolation Pilot Plant (WIPP) in New Mexico. Borosilicate glass (BSG), the approved high-level waste form, appears unsuited for this application. Melting the average waste-soil mix from the RWMC produces the IEB composition and attempting to convert IEB to the BSG composition would require additions of substantial B 2 0 3 , Na, and SiO 2 (glass frit). IEB requires processing temperatures of 1400 to 1600 degrees C, depending upon the waste composition. Production of the IEB waste form, using Joule heated melters, has proved difficult in the past because of electrode and refractory corrosion problems associated with the high temperature melts. Higher temperature electric melters (arc and plasma) are available to produce this final waste form. Past research focused on extensive slag property measurements, waste form leachability tests, mechanical, composition, and microstructure evaluations, as well as a host of experiments to improve production of the waste form. Past INEL studies indicated that the IEB glass-ceramic is a material that will accommodate and stabilize a wide range of heterogeneous waste materials, including long lived radionuclides and scrap metals, while maintaining a superior level of chemical and physical performance characteristics. Controlled cooling of the molten IEB and subsequent heat treatment will produce a glass-ceramic waste form with superior leach resistance

Platelet-Rich Fibrin and Soft Tissue Wound Healing: A Systematic Review.

Science.gov (United States)

Miron, Richard J; Fujioka-Kobayashi, Masako; Bishara, Mark; Zhang, Yufeng; Hernandez, Maria; Choukroun, Joseph

2017-02-01

The growing multidisciplinary field of tissue engineering aims at predictably regenerating, enhancing, or replacing damaged or missing tissues for a variety of conditions caused by trauma, disease, and old age. One area of research that has gained tremendous awareness in recent years is that of platelet-rich fibrin (PRF), which has been utilized across a wide variety of medical fields for the regeneration of soft tissues. This systematic review gathered all the currently available in vitro, in vivo, and clinical literature utilizing PRF for soft tissue regeneration, augmentation, and/or wound healing. In total, 164 publications met the original search criteria, with a total of 48 publications meeting inclusion criteria (kappa score = 94%). These studies were divided into 7 in vitro, 11 in vivo, and 31 clinical studies. In summary, 6 out of 7 (85.7%) and 11 out of 11 (100%) of the in vitro and in vivo studies, respectively, demonstrated a statistically significant advantage for combining PRF to their regenerative therapies. Out of the remaining 31 clinical studies, a total of 8 reported the effects of PRF in a randomized clinical trial, with 5 additional studies (13 total) reporting appropriate controls. In those clinical studies, 9 out of the 13 studies (69.2%) demonstrated a statistically relevant positive outcome for the primary endpoints measured. In total, 18 studies (58% of clinical studies) reported positive wound-healing events associated with the use of PRF, despite using controls. Furthermore, 27 of the 31 clinical studies (87%) supported the use of PRF for soft tissue regeneration and wound healing for a variety of procedures in medicine and dentistry. In conclusion, the results from the present systematic review highlight the positive effects of PRF on wound healing after regenerative therapy for the management of various soft tissue defects found in medicine and dentistry.

(Per)Forming Archival Research Methodologies

Science.gov (United States)

Gaillet, Lynee Lewis

2012-01-01

This article raises multiple issues associated with archival research methodologies and methods. Based on a survey of recent scholarship and interviews with experienced archival researchers, this overview of the current status of archival research both complicates traditional conceptions of archival investigation and encourages scholars to adopt…

Review by a local medical research ethics committee of the conduct of approved research projects, by examination of patients' case notes, consent forms, and research records and by interview.

Science.gov (United States)

Smith, T; Moore, E J; Tunstall-Pedoe, H

1997-05-31

To monitor the conduct of medical research projects that have already been approved by the local medical research ethics committee. Follow up study of ethically approved studies (randomly selected from all the studies approved in the previous year) by examination of patients' case notes, consent forms, and research records and by interview of the researchers at their workplace. Tayside, Scotland (mixed rural and urban population). 30 research projects approved by Tayside local medical research ethics committee. Adherence to the agreed protocol, particularly for recruitment (obtaining and recording informed consent) and for specific requirements of the ethics committee, including notification of changes to the protocol and of adverse events. In one project only oral consent had been obtained, and in a quarter of the studies one or more consent forms were incorrectly completed. Inadequate filing of case notes in five studies and of consent forms in six made them unavailable for scrutiny. Adverse events were reported, but there was a general failure to report the abandoning or non-starting of projects in two studies the investigators failed to notify a change in the responsible researcher. Monitoring of medical research by local medical research ethics committees promotes and preserves ethical standards, protects subjects and researchers, discourages fraud, and has the support of investigators. We recommend that 10% of projects should undergo on-site review, with all others monitored by questionnaire. This would require about six person hours of time and a salary bill of 120 pounds per study monitored.

The effect of platelet-rich fibrin on implant stability.

Science.gov (United States)

Öncü, Elif; Alaaddinoğlu, E Emine

2015-01-01

Achieving accelerated implant osseointegration could make immediate or early loading of implants more predictable. Platelet-rich fibrin (PRF) is frequently used to accelerate soft and hard tissue healing. The activated platelets in PRF release growth factors, resulting in cellular proliferation, collagen synthesis, and osteoid production. The aim of this study was to compare the stability of dental implants inserted in a one-stage surgical protocol with or without PRF application. Twenty healthy patients with adequate alveolar bone and two or more adjacent missing teeth extracted at least 6 months previously were included in this study. A minimum of two tapered implants (Ankylos, Dentsply/Friadent) were placed in each patient. After surgical preparation of the implant sockets, PRF that had been prepared preoperatively was placed randomly into one of the sockets (PRF+). The acellular plasma portion of PRF was used to wet the implant placed into the PRF-coated socket. Resonance frequency measurements were made after implant placement and at 1 week and 1 month postoperatively. Mean implant stability quotients (ISQs) of the PRF+ implants was 69.3 ± 10.5, and mean ISQs for the PRF- implants was 64.5 ± 12.2 at the end of the first week. The mean ISQs at 4 weeks postoperatively were 77.1 ± 7.1 for the PRF+ group and 70.5 ± 7.7 for the PRF- group. In this study, PRF application increased implant stability during the early healing period, as evidenced by higher ISQ values. Simple application of this material seems to provide faster osseointegration.

Self-plagiarism and textual recycling: legitimate forms of research misconduct.

Science.gov (United States)

Bruton, Samuel V

2014-01-01

The concept of self-plagiarism frequently elicits skepticism and generates confusion in the research ethics literature, and the ethical status of what is often called "textual recycling" is particularly controversial. I argue that, in general, self-plagiarism is unethical because it is deceptive and dishonest. I then distinguish several forms of it and argue against various common rationalizations for textual recycling. I conclude with a discussion of two instances of textual recycling, distinguishing them in terms of their ethical seriousness but concluding that both are ethically problematic.

REM sleep enhancement and behavioral cataplexy following orexin (hypocretin)-II receptor antisense perfusion in the pontine reticular formation.

Science.gov (United States)

Thakkar, M M; Ramesh, V; Cape, E G; Winston, S; Strecker, R E; McCarley, R W

1999-01-01

Orexin (hypocretin)-containing neurons of the hypothalamus project to brainstem sites that are involved in the neural control of REM sleep, including the locus coeruleus, the dorsal raphe nucleus, the cholinergic zone of the mesopontine tegmentum, and the pontine reticular formation (PRF). Orexin knockout mice exhibit narcolepsy/cataplexy, and a mutant and defective gene for the orexin type II receptor is present in dogs with an inherited form of narcolepsy/cataplexy. However, the physiological systems mediating these effects have not been described. We reasoned that, since the effector neurons for the majority of REM sleep signs, including muscle atonia, were located in the PRF, this region was likely implicated in the production of these orexin-related abnormalities. To test this possibility, we used microdialysis perfusion of orexin type II receptor antisense in the PRF of rats. Ten to 24 hours after antisense perfusion, REM sleep increased two- to three-fold during both the light period (quiescent phase) and the dark period (active phase), and infrared video showed episodes of behavioral cataplexy. Moreover, preliminary data indicated no REM-related effects following perfusion with nonsense DNA, or when perfusion sites were outside the PRF. More work is needed to provide precise localization of the most effective site of orexin-induced inhibition of REM sleep phenomena.

Platelet-rich fibrin in the treatment of periodontal bone defects.

Science.gov (United States)

Ranganathan, Aravindhan T; Chandran, Chitraa R

2014-05-01

Periodontitis is characterized by the formation of true pockets, bone loss and attachment loss. Various techniques have been attempted in the past to truly regenerate the lost periodontal structures, albeit with variable outcome. In this evolution, the technique being tried out widely is the use of platelet rich concentrates, namely platelet-rich fibrin (PRF). In this report, we present a case of surgical treatment of osseous bone defects namely two walled crater and dehiscence treated in posterior teeth with autologously prepared platelet rich fibrin mixed with hydroxy apatite bone graft and PRF in the form of a membrane. Our results showed clinical improvements in all the clinical parameters postoperatively namely the pocket depth reduction and gain in attachment level and hence, PRF can be used alone or in combination with the bone graft to yield successful clinical results in treating periodontal osseous defects. Platelet-rich fibrin is an effective alternative to platelet-rich plasma (PRP) in reconstructing bone defects.

Fear and Reward Circuit Alterations in Pediatric CRPS.

Science.gov (United States)

Simons, Laura E; Erpelding, Nathalie; Hernandez, Jessica M; Serrano, Paul; Zhang, Kunyu; Lebel, Alyssa A; Sethna, Navil F; Berde, Charles B; Prabhu, Sanjay P; Becerra, Lino; Borsook, David

2015-01-01

In chronic pain, a number of brain regions involved in emotion (e.g., amygdala, hippocampus, nucleus accumbens, insula, anterior cingulate, and prefrontal cortex) show significant functional and morphometric changes. One phenotypic manifestation of these changes is pain-related fear (PRF). PRF is associated with profoundly altered behavioral adaptations to chronic pain. For example, patients with a neuropathic pain condition known as complex regional pain syndrome (CRPS) often avoid use of and may even neglect the affected body area(s), thus maintaining and likely enhancing PRF. These changes form part of an overall maladaptation to chronic pain. To examine fear-related brain circuit alterations in humans, 20 pediatric patients with CRPS and 20 sex- and age-matched healthy controls underwent functional magnetic resonance imaging (fMRI) in response to a well-established fearful faces paradigm. Despite no significant differences on self-reported emotional valence and arousal between the two groups, CRPS patients displayed a diminished response to fearful faces in regions associated with emotional processing compared to healthy controls. Additionally, increased PRF levels were associated with decreased activity in a number of brain regions including the right amygdala, insula, putamen, and caudate. Blunted activation in patients suggests that (a) individuals with chronic pain may have deficits in cognitive-affective brain circuits that may represent an underlying vulnerability or consequence to the chronic pain state; and (b) fear of pain may contribute and/or maintain these brain alterations. Our results shed new light on altered affective circuits in patients with chronic pain and identify PRF as a potentially important treatment target.

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

OpenAIRE

Mustafa Tunalı; Hakan Özdemir; Zafer Küçükodacı; Serhan Akman; Emre Yaprak; Hülya Toker; Erhan Fıratlı

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn us...

Comparison of Gasoline and Primary Reference Fuel in the Transition from HCCI to PPC

KAUST Repository

Li, Changle

2017-10-10

Our previous research investigated the sensitivity of combustion phasing to intake temperature and injection timing during the transition from homogeneous charge compression ignition (HCCI) to partially premixed combustion (PPC) fuelled with generic gasoline. The results directed particular attention to the relationship between intake temperature and combustion phasing which reflected the changing of stratification level with the injection timing. To confirm its applicability with the use of different fuels, and to investigate the effect of fuel properties on stratification formation, primary reference fuels (PRF) were tested using the same method: a start of injection sweep from -180° to -20° after top dead center with constant combustion phasing by tuning the intake temperature. The present results are further developed compared with those of our previous work, which were based on generic gasoline. In the present work, a three-stage fuel-air stratification development process was observed during the transition from HCCI to PPC. Moreover, a transition stage was observed between the HCCI and PPC stages. Within this transition stage, both the combustion and emission characteristics deteriorated. The allocation of this transition area was mainly determined by the geometric design of the fuel injector and combustion chamber. Some differences in charge stratification were observed between the PRF and gasoline. The NO emissions of the PRF were comparable to those of gasoline. However, the NO emissions surged during the transition stage, indicating that the PRF combustion was probably more stratified. The soot emissions from PRF and gasoline were both much higher in the PPC than the HCCI mode, though the PRF produced much less soot than did gasoline in the PPC mode.

Guides and forms | IDRC - International Development Research ...

International Development Research Centre (IDRC) Digital Library (Canada)

Information for suppliers and consultants. Consultancies: Frequently Asked Questions · Canadian Supplier — Tax and Bank Information Form · T1204 – Government services contract payments · Supplier Outside of Canada — Tax and Bank Information Form ...

On the Usefulness of a Multilevel Logistic Regression Approach to Person-Fit Analysis

Science.gov (United States)

Conijn, Judith M.; Emons, Wilco H. M.; van Assen, Marcel A. L. M.; Sijtsma, Klaas

2011-01-01

The logistic person response function (PRF) models the probability of a correct response as a function of the item locations. Reise (2000) proposed to use the slope parameter of the logistic PRF as a person-fit measure. He reformulated the logistic PRF model as a multilevel logistic regression model and estimated the PRF parameters from this…

Research Status on Reinforcement Connection Form of Precast Concrete Shear Wall Structure

Science.gov (United States)

Zhang, Zhuangnan; Zhang, Yan

2018-03-01

With the rapid development of Chinese economy and the speeding up the process of urbanization, housing industrialization has been paid more and more attention. And the fabricated structure has been widely used in China. The key of precast concrete shear wall structure is the connection of precast components. The reinforcement connection can directly affect the entirety performance and seismic behavior of the structure. Different reinforcement connections have a great impact on the overall behavior of the structure. By studying the characteristics of the reinforcement connection forms used in the vertical connection and horizontal connection of precast concrete shear wall, it can provide reference for the research and development of the reinforcement connection forms in the future.

Pulsed radiofrequency treatment of articular branches of femoral and obturator nerves for chronic hip pain.

Science.gov (United States)

Chye, Cien-Leong; Liang, Cheng-Loong; Lu, Kang; Chen, Ya-Wen; Liliang, Po-Chou

2015-01-01

Chronic hip pain is a common symptom experienced by many people. Often, surgery is not an option for patients with multiple comorbidities, and conventional drugs either have many side effects or are ineffective. Pulsed radiofrequency (PRF) is a new method in the treatment of pain. We attempt to compare the efficacy of PRF relative to conservative management for chronic hip pain. Between August 2011 and July 2013, 29 patients with chronic hip pain were divided into two groups (PRF and conservative treatment) according to consent or refusal to undergo PRF procedure. Fifteen patients received PRF of the articular branches of the femoral and obturator nerves, and 14 patients received conservative treatment. Visual analog scale (VAS), Oxford hip scores (OHS), and pain medications were used for outcome measurement before treatment and at 1 week, 4 weeks, and 12 weeks after treatment. At 1 week, 4 weeks, and 12 weeks after treatment initiation, improvements in VAS were significantly greater with PRF. Improvements in OHS were significantly greater in the PRF group at 1 week, 4 weeks, and 12 weeks. Patients in the PRF group also used less pain medications. Eight subjects in the conservative treatment group switched to the PRF group after 12 weeks, and six of them had >50% improvement. When compared with conservative treatment, PRF of the articular branches of the femoral and obturator nerves offers greater pain relief for chronic hip pain and can augment physical functioning.

Designing adverse event forms for real-world reporting: participatory research in Uganda.

Directory of Open Access Journals (Sweden)

Emma C Davies

Full Text Available The wide-scale roll-out of artemisinin combination therapies (ACTs for the treatment of malaria should be accompanied by continued surveillance of their safety. Post-marketing pharmacovigilance (PV relies on adverse event (AE reporting by clinicians, but as a large proportion of treatments are provided by non-clinicians in low-resource settings, the effectiveness of such PV systems is limited. To facilitate reporting, AE forms should be easily completed; however, most are challenging for lower-level health workers and non-clinicians to complete. Through participatory research, we sought to develop user-friendly AE report forms to capture information on events associated with ACTs.Following situation analysis, we undertook workshops with community medicine distributors and health workers in Jinja, Uganda, to develop a reporting form based on experiences and needs of users, and communication and visual perception principles. Participants gave feedback for revisions of subsequent versions. We then conducted 8 pretesting sessions with 77 potential end users to test and refine passive and active versions of the form.The development process resulted in a form that included a pictorial storyboard to communicate the rationale for the information needed and facilitate rapport between the reporter and the respondent, and a diary format to record the drug administration and event details in chronological relation to each other. Successive rounds of pretesting used qualitative and quantitative feedback to refine the form, with the final round showing over 80% of the form completed correctly by potential end users.We developed novel AE report forms that can be used by non-clinicians to capture pharmacovigilance data for anti-malarial drugs. The participatory approach was effective for developing forms that are intuitive for reporters, and motivating for respondents. The forms, or their key components, could be adapted for use in other low-literacy settings

Designing adverse event forms for real-world reporting: participatory research in Uganda.

Science.gov (United States)

Davies, Emma C; Chandler, Clare I R; Innocent, Simeon H S; Kalumuna, Charles; Terlouw, Dianne J; Lalloo, David G; Staedke, Sarah G; Haaland, Ane

2012-01-01

The wide-scale roll-out of artemisinin combination therapies (ACTs) for the treatment of malaria should be accompanied by continued surveillance of their safety. Post-marketing pharmacovigilance (PV) relies on adverse event (AE) reporting by clinicians, but as a large proportion of treatments are provided by non-clinicians in low-resource settings, the effectiveness of such PV systems is limited. To facilitate reporting, AE forms should be easily completed; however, most are challenging for lower-level health workers and non-clinicians to complete. Through participatory research, we sought to develop user-friendly AE report forms to capture information on events associated with ACTs.Following situation analysis, we undertook workshops with community medicine distributors and health workers in Jinja, Uganda, to develop a reporting form based on experiences and needs of users, and communication and visual perception principles. Participants gave feedback for revisions of subsequent versions. We then conducted 8 pretesting sessions with 77 potential end users to test and refine passive and active versions of the form.The development process resulted in a form that included a pictorial storyboard to communicate the rationale for the information needed and facilitate rapport between the reporter and the respondent, and a diary format to record the drug administration and event details in chronological relation to each other. Successive rounds of pretesting used qualitative and quantitative feedback to refine the form, with the final round showing over 80% of the form completed correctly by potential end users.We developed novel AE report forms that can be used by non-clinicians to capture pharmacovigilance data for anti-malarial drugs. The participatory approach was effective for developing forms that are intuitive for reporters, and motivating for respondents. The forms, or their key components, could be adapted for use in other low-literacy settings to improve quality

Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

OpenAIRE

Baranowski, Przemysław; Karolewicz, Bożena; Gajda, Maciej; Pluta, Janusz

2014-01-01

This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to...

Enhanced antitumor effects of novel intracellular delivery of an active form of menaquinone-4, menahydroquinone-4, into hepatocellular carcinoma.

Science.gov (United States)

Setoguchi, Shuichi; Watase, Daisuke; Matsunaga, Kazuhisa; Matsubara, Misa; Kubo, Yohei; Kusuda, Mariko; Nagata-Akaho, Nami; Enjoji, Munechika; Nakashima, Manabu; Takeshita, Morishige; Karube, Yoshiharu; Takata, Jiro

2015-02-01

Reduced cellular uptake of menaquinone-4 (MK-4), a vitamin K2 homolog, in human hepatocellular carcinoma (HCC) limits its usefulness as a safe long-term antitumor agent for recurrent HCC and produces des-γ-carboxy prothrombin (DCP). We hypothesized that effective delivery of menahydroquinone-4 (MKH), the active form of MK-4 for γ-glutamyl carboxylation, into HCC cells is critical for regulating HCC growth, and may enable it to be applied as a safe antitumor agent. In this study, we verified this hypothesis using menahydroquinone-4 1,4-bis-N,N-dimethylglycinate hydrochloride (MKH-DMG), a prodrug of MKH, and demonstrated its effectiveness. Intracellular delivery of MKH and subsequent growth inhibition of PLC/PRF/5 and Hep3B (DCP-positive) and SK-Hep-1 (DCP-negative) cells after MKH-DMG administration were determined and compared with MK-4. The activity of MKH-DMG against tumor progression in the liver alongside DCP formation was determined in a spleen-liver metastasis mouse model. MKH-DMG exhibited greater intracellular delivery of MKH in vitro (AUC0-72 hour of MKH) and increased growth-inhibitory activity against both DCP-positive and DCP-negative HCC cell lines. The phenomena of MKH delivery into cells in parallel with simultaneous growth inhibition suggested that MKH is the active form for growth inhibition of HCC cells. Cell-cycle arrest was determined to be involved in the growth inhibition mechanisms of MKH-DMG. Furthermore, MKH-DMG showed significant inhibition of tumor progression in the liver, and a substantial decrease in plasma DCP levels in the spleen-liver metastasis mouse model. Our results suggest that MKH-DMG is a promising new candidate antitumor agent for safe long-term treatment of HCC. ©2014 American Association for Cancer Research.

Review by a local medical research ethics committee of the conduct of approved research projects, by examination of patients' case notes, consent forms, and research records and by interview.

OpenAIRE

Smith, T.; Moore, E. J.; Tunstall-Pedoe, H.

1997-01-01

OBJECTIVE: To monitor the conduct of medical research projects that have already been approved by the local medical research ethics committee. DESIGN: Follow up study of ethically approved studies (randomly selected from all the studies approved in the previous year) by examination of patients' case notes, consent forms, and research records and by interview of the researchers at their workplace. SETTING: Tayside, Scotland (mixed rural and urban population). SUBJECTS: 30 research projects app...

The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

International Nuclear Information System (INIS)

Śpiewak, Mateusz; Małek, Łukasz A.; Petryka, Joanna; Mazurkiewicz, Łukasz; Miłosz, Barbara; Biernacka, Elżbieta K.; Kowalski, Mirosław; Hoffman, Piotr; Demkow, Marcin; Miśko, Jolanta; Rużyłło, Witold

2012-01-01

Background: Previous studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m 2 ). Methods: Consecutive patients with repaired tetralogy of Fallot were included (n = 53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance. Results: RVEDV was more closely correlated with PRV when compared with PRF (r = 0.686, p 2.0 [area under the curve (AUC) PRV = 0.770 vs AUC PRF = 0.777, p = 0.86]. Conversely, with the use of the RVEDV-based criterion (>170 mL/m 2 ), PRV proved to be superior over PRF (AUC PRV = 0.770 vs AUC PRF = 0.656, p = 0.0028]. Conclusions: PRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV)

Effect of Pulsed Radiofrequency on Rat Sciatic Nerve Chronic Constriction Injury: A Preliminary Study

Directory of Open Access Journals (Sweden)

Duo-Yi Li

2015-01-01

Full Text Available Background: Pulsed radiofrequency (PRF application to the dorsal root ganglia can reduce neuropathic pain (NP in animal models, but the effect of PRF on damaged peripheral nerves has not been examined. We investigated the effect of PRF to the rat sciatic nerve (SN on pain-related behavior and SN ultrastructure following chronic constriction injury (CCI. Methods: The analgesic effect was measured by hindpaw mechanical withdrawal threshold (MWT and thermal withdrawal latency (TWL. Twenty rats with NP induced by ligating the common SN were then randomly divided into a PRF treatment group and a sham group. The contralateral SN served as a control. The MWT and TWL were determined again 2, 4, 6, 8, 10, 12, and 14 days after the PRF or sham treatment. On day 14, ipsilateral and contralateral common SNs were excised and examined by electron microscopy. Results: Ipsilateral MWT was significantly reduced and TWL significantly shorter compared to the contralateral side 14 days after CCI (both P = 0.000. In the PRF group, MWT was significantly higher and TWL significantly longer 14 days after the PRF treatment compared to before PRF treatment (both P = 0.000, while no such difference was observed in the sham group (P > 0.05. Electron microscopy revealed extensive demyelination and collagen fiber formation in the ipsilateral SN of sham-treated rats but sparse demyelination and some nerve fiber regrowth in the PRF treatment group. Conclusions: Hyperalgesia is relieved, and ultrastructural damage ameliorated after direct PRF treatment to the SN in the CCI rat model of NP.

Effect of Pulsed Radiofrequency on Rat Sciatic Nerve Chronic Constriction Injury: A Preliminary Study

Science.gov (United States)

Li, Duo-Yi; Meng, Lan; Ji, Nan; Luo, Fang

2015-01-01

Background: Pulsed radiofrequency (PRF) application to the dorsal root ganglia can reduce neuropathic pain (NP) in animal models, but the effect of PRF on damaged peripheral nerves has not been examined. We investigated the effect of PRF to the rat sciatic nerve (SN) on pain-related behavior and SN ultrastructure following chronic constriction injury (CCI). Methods: The analgesic effect was measured by hindpaw mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). Twenty rats with NP induced by ligating the common SN were then randomly divided into a PRF treatment group and a sham group. The contralateral SN served as a control. The MWT and TWL were determined again 2, 4, 6, 8, 10, 12, and 14 days after the PRF or sham treatment. On day 14, ipsilateral and contralateral common SNs were excised and examined by electron microscopy. Results: Ipsilateral MWT was significantly reduced and TWL significantly shorter compared to the contralateral side 14 days after CCI (both P = 0.000). In the PRF group, MWT was significantly higher and TWL significantly longer 14 days after the PRF treatment compared to before PRF treatment (both P = 0.000), while no such difference was observed in the sham group (P > 0.05). Electron microscopy revealed extensive demyelination and collagen fiber formation in the ipsilateral SN of sham-treated rats but sparse demyelination and some nerve fiber regrowth in the PRF treatment group. Conclusions: Hyperalgesia is relieved, and ultrastructural damage ameliorated after direct PRF treatment to the SN in the CCI rat model of NP. PMID:25673460

Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

Directory of Open Access Journals (Sweden)

Przemysław Baranowski

2014-01-01

Full Text Available This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommended in vitro and in vivo studies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.

ACCURACY RESEARCH OF THE DIAMETRICAL SIZES FORMING AT GEAR SHAPING BY STEPPED CUTTER

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N. M. Rasulov

2015-09-01

Full Text Available The paper presents research results of forming accuracy for diametrical sizes at gear shaping with stepped cutter and the traditional method. Analysis of static technological dimensional pitch size chain of wheels being cut is performed. It was revealed that the most of transmission errors of the wheels, formed by the traditional gear-shaped cutter are caused by manufacturing and installation error of the cutter and result from the formation of each tooth of the wheel with a certain tool. This is not the case with gear shaping by step cutter since at that, the profiles of all gear teeth are formed by means of tooth profile mostly remote from the tool rotation axis. Analysis of occurrence of setting-up errors typical for the above gear shaping methods has been performed. At gear shaping with stepped cutter there are no setting-up error components. It was revealed that this fact causes the absence of errors in the tool position before its each double motion. The accuracy of diametrical sizes increases. Formation mechanism of tool installation errors and workpiece are also given and their analysis is presented. Findings in the field of gear shaping with stepped cutter comply with results of research carried out by the other authors in the field of traditional gear shaping.

2-Methylfuran: A bio-derived octane booster for spark-ignition engines

KAUST Repository

Sarathy, Mani

2018-04-02

The efficiency of spark-ignition engines is limited by the phenomenon of knock, which is caused by auto-ignition of the fuel-air mixture ahead of the spark-initiated flame front. The resistance of a fuel to knock is quantified by its octane index; therefore, increasing the octane index of a spark-ignition engine fuel increases the efficiency of the respective engine. However, raising the octane index of gasoline increases the refining costs, as well as the energy consumption during production. The use of alternative fuels with synergistic blending effects presents an attractive option for improving octane index. In this work, the octane enhancing potential of 2-methylfuran (2-MF), a next-generation biofuel, has been examined and compared to other high-octane components (i.e., ethanol and toluene). A primary reference fuel with an octane index of 60 (PRF60) was chosen as the base fuel since it closely represents refinery naphtha streams, which are used as gasoline blend stocks. Initial screening of the fuels was done in an ignition quality tester (IQT). The PRF60/2-MF (80/20 v/v%) blend exhibited longer ignition delay times compared to PRF60/ethanol (80/20 v/v%) blend and PRF60/toluene (80/20 v/v%) blend, even though pure 2-MF is more reactive than both ethanol and toluene. The mixtures were also tested in a cooperative fuels research (CFR) engine under research octane number and motor octane number like conditions. The PRF60/2-MF blend again possesses a higher octane index than other blending components. A detailed chemical kinetic analysis was performed to understand the synergetic blending effect of 2-MF, using a well-validated PRF/2-MF kinetic model. Kinetic analysis revealed superior suppression of low-temperature chemistry with the addition of 2-MF. The results from simulations were further confirmed by homogeneous charge compression ignition engine experiments, which established its superior low-temperature heat release (LTHR) suppression compared to ethanol

INVOLVING STUDENTS IN RESEARCH AS A FORM OF INTEGRATION OF ENGINEERING WITH MATHEMATICAL EDUCATION

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Viktor M. Fedoseyev

2016-03-01

Full Text Available Introduction: questions of integration of mathematical with engineering training in educational process of higher education institution are explored. The existing technologies of the integrated training are analyzed, and the project-oriented direction is distinguished. Research involving students as an organisational and methodical form of training bachelors of the technical speciali sations is discussed. Materials and Methods: results of article are based on researches of tendencies of development of technical and mathematical education, works on the theory and methodology of pedagogical integration, methodology of mathematics and technical science. Methods of historical and pedagogical research, analytical, a method of mathematical modeling were used. Results: the main content of the paper is to make discussion of experience in developing and using integrated educational tasks in real educational process. Discussion is based on a specific technological assignment including a number of mathematical tasks used as a subject of research for students. In the assignment a special place is allocated to the questions reflecting the interplay of a technical task with a mathematical method of research highlighting the objective significance of mathematics as a method to solve engineering problems. Discussion and Conclusions: the paper gives reasons to conditions for using research work with students as an organisational and methodical form of integrated training in mathematics. In realisation of educational technology it is logical to apply the method of projects. It is necessary to formulate a task as an engineering project: to set an engineering objective of research, to formulate specifications; to differentiate between engineering and mathematical tasks of the project, to make actual interrelations between them; the mathematical part of the project has to be a body of research; assessment of the project must be carried out not only accounting for

BANSHEE: High-voltage repetitively pulsed electron-beam driver

International Nuclear Information System (INIS)

VanHaaften, F.

1992-01-01

BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-μs pulse width driving a load of ∼100 Ω, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 Ω, up to a level of ∼650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of ∼100 Ω

Dual-species biofilm of Listeria monocytogenes and Escherichia coli on stainless steel surface.

Science.gov (United States)

de Grandi, Aline Zago; Pinto, Uelinton Manoel; Destro, Maria Teresa

2018-04-12

Listeria monocytogenes is a Gram-positive bacterium commonly associated with foodborne diseases. Due its ability to survive under adverse environmental conditions and to form biofilm, this bacterium is a major concern for the food industry, since it can compromise sanitation procedures and increase the risk of post-processing contamination. Little is known about the interaction between L. monocytogenes and Gram-negative bacteria on biofilm formation. Thus, in order to evaluate this interaction, Escherichia coli and L. monocytogenes were tested for their ability to form biofilms together or in monoculture. We also aimed to evaluate the ability of L. monocytogenes 1/2a and its isogenic mutant strain (ΔprfA ΔsigB) to form biofilm in the presence of E. coli. We assessed the importance of the virulence regulators, PrfA and σ B , in this process since they are involved in many aspects of L. monocytogenes pathogenicity. Biofilm formation was assessed using stainless steel AISI 304 #4 slides immersed into brain heart infusion broth, reconstituted powder milk and E. coli preconditioned medium at 25 °C. Our results indicated that a higher amount of biofilm was formed by the wild type strain of L. monocytogenes than by its isogenic mutant, indicating that prfA and sigB are important for biofilm development, especially maturation under our experimental conditions. The presence of E. coli or its metabolites in preconditioned medium did not influence biofilm formation by L. monocytogenes. Our results confirm the possibility of concomitant biofilm formation by L. monocytogenes and E. coli, two bacteria of major significance in the food industry.

Basics of case report form designing in clinical research.

Science.gov (United States)

Bellary, Shantala; Krishnankutty, Binny; Latha, M S

2014-10-01

Case report form (CRF) is a specialized document in clinical research. It should be study protocol driven, robust in content and have material to collect the study specific data. Though paper CRFs are still used largely, use of electronic CRFs (eCRFS) are gaining popularity due to the advantages they offer such as improved data quality, online discrepancy management and faster database lock etc. Main objectives behind CRF development are preserving and maintaining quality and integrity of data. CRF design should be standardized to address the needs of all users such as investigator, site coordinator, study monitor, data entry personnel, medical coder and statistician. Data should be organized in a format that facilitates and simplifies data analysis. Collection of large amount of data will result in wasted resources in collecting and processing it and in many circumstances, will not be utilized for analysis. Apart from that, standard guidelines should be followed while designing the CRF. CRF completion manual should be provided to the site personnel to promote accurate data entry by them. These measures will result in reduced query generations and improved data integrity. It is recommended to establish and maintain a library of templates of standard CRF modules as they are time saving and cost-effective. This article is an attempt to describe the methods of CRF designing in clinical research and discusses the challenges encountered in this process.

A new improvement on a chemical kinetic model of primary reference fuel for multi-dimensional CFD simulation

International Nuclear Information System (INIS)

Zhen, Xudong; Wang, Yang; Liu, Daming

2016-01-01

Highlights: • A new optimized chemical kinetic mechanism for PRF is developed. • New mechanism optimization is performed based on the CHEMKIN simulations. • More reactions of C_0–C_1 oxidation are added in the present mechanism. • Good performance is achieved of mechanism by validating various reactors and operating conditions. - Abstract: In the present study, for the multi-dimensional CFD (computational fluid dynamics) combustion simulations of internal combustion engines, a new optimized chemical kinetic reaction mechanism for the oxidation of PRF (primary reference fuel) instead of gasoline has been developed. In order to carry out the in-depth research for combustion phenomenon of internal combustion engines, an optimized reduced PRF mechanism including more intermediate species and radicals was developed. The developed mechanism contains of iso-octane (C_8H_1_8) and n-heptane (C_7H_1_6) surrogates, which contains of 51-species and 193 reactions. Compared with many other mechanisms of PRF, more reactions of C_0–C_1 oxidation (100 reactions) are added in the present mechanism. In order to improve the performances of the model, the developed mechanism focused on the improvement through the prediction of the ignition delay time. The developed mechanism has been validated against various experimental and simulation data including shock tube data, laminar flame speed data and HCCI (homogeneous charge compression ignition) engine data. The results showed that the developed PRF mechanism was agreements with the experimental data and other approved reduced mechanisms, and it could be applied to the multi-dimensional CFD simulations for internal combustion engines.

Acute Psychosocial Stress-Mediated Changes in the Expression and Methylation of Perforin in Chronic Fatigue Syndrome

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Virginia R. Falkenberg

2013-01-01

Full Text Available Perforin ( PRF1 is essential for immune surveillance and studies report decreased perforin in chronic fatigue syndrome (CFS, an illness potentially associated with stress and/or infection. We hypothesize that stress can influence regulation of PRF1 expression, and that this regulation will differ between CFS and non-fatigued (NF controls. We used the Trier Social Stress Test (TSST as a standardized acute psychosocial stress, and evaluated its effect on PRF1 expression and methylation in CFS (n = 34 compared with NF (n = 47 participants. During the TSST, natural killer (NK cells increased significantly in both CFS ( P = <0.0001 and NF subjects ( P = <0.0001. Unlike previous reports, there was no significant difference in PRF1 expression at baseline or during TSST between CFS and NF. However, whole blood PRF1 expression increased 1.6 fold during the TSST in both CFS ( P = 0.0003 and NF ( P = <0.0001. Further, the peak response immediately following the TSST was lower in CFS compared with NF ( P = 0.04. In addition, at 1.5 hours post TSST, PRF1 expression was elevated in CFS compared with NF (whole blood, P = 0.06; PBMC, P = 0.02. Methylation of seven CpG sites in the methylation sensitive region of the PRF1 promoter ranged from 38%-79% with no significant differences between CFS and NF. Although, the average baseline methylation of all seven CpG sites did not differ between CFS and NF groups, it showed a significant negative correlation with PRF1 expression at all TSST time points in both CFS (r = –0.56, P = <0.0001 and NF (r = –0.38, P = <0.0001. Among participants with high average methylation (≥65%, PRF1 expression was significantly lower in CFS than NF subjects immediately following TSST. These findings suggest methylation could be an important epigenetic determinant of inter-individual differences in PRF1 expression and that the differences in PRF1 expression and methylation between CFS and NF in the acute stress response require

Comparison of the Regenerative Effects of Platelet-Rich Fibrin and Plasma Rich in Growth Factors on Injured Peripheral Nerve: An Experimental Study.

Science.gov (United States)

Torul, Damla; Bereket, Mehmet Cihan; Onger, Mehmet Emin; Altun, Gamze

2018-04-20

The aim of this study was to investigate the effects of platelet-rich fibrin (PRF) and plasma rich in growth factors (PRGF) on peripheral nerve injury in the early period of healing. Thirty Wistar albino rats were used in this study. Rats were divided into control (C), damaged (D), PRF, and PRGF groups. The left sciatic nerves of each group were identified as group C. Crush-type injury was performed on the right sciatic nerves of the D, PRF, and PRGF groups. In the PRF and PRGF groups, blood 2 mL was obtained to prepare the PRF and PRGF and the biomaterials were applied to the injured nerve area. After 8 weeks, functional, electrophysiologic, and stereological evaluations were performed. For the electrophysiologic evaluation, the latency and amplitude values in the D, PRF, and PRGF groups were significantly lower than those in the C group (P > .05). According to the sciatic functional index result, there were significant differences between groups D and PRF and between groups D and PRGF (P = .000). For the stereological evaluations, although no significant difference was observed between the PRGF and C groups (P > .05), a significant difference was observed among the D, PRF, and PRGF groups for myelinated axon number. There were significant differences between groups D and PRF and between groups D and PRGF for axon area (P = .021 and .001, respectively). No significant difference was observed among the D, PRF, and PRGF groups for myelin sheath thickness and ratio of axon area to myelin sheath thickness (P > .05). The results of this study suggest that PRGF increases nerve regeneration in the early period of healing and that the limited early action of PRF should be re-evaluated in the late period. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Vasoactive intestinal polypeptide excites medial pontine reticular formation neurons in the brainstem rapid eye movement sleep-induction zone

DEFF Research Database (Denmark)

Kohlmeier, Kristi Anne; Reiner, P B

1999-01-01

Although it has long been known that microinjection of the cholinergic agonist carbachol into the medial pontine reticular formation (mPRF) induces a state that resembles rapid eye movement (REM) sleep, it is likely that other transmitters contribute to mPRF regulation of behavioral states. A key...... candidate is the peptide vasoactive intestinal polypeptide (VIP), which innervates the mPRF and induces REM sleep when injected into this region of the brainstem. To begin understanding the cellular mechanisms underlying this phenomenon, we examined the effects of VIP on mPRF cells using whole-cell patch...... conclude that VIP excites mPRF neurons by activation of a sodium current. This effect is mediated at least in part by G-protein stimulation of adenylyl cyclase, cAMP, and protein kinase A. These data suggest that VIP may play a physiological role in REM induction by its actions on mPRF neurons....

The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

Energy Technology Data Exchange (ETDEWEB)

Śpiewak, Mateusz, E-mail: mspiewak@ikard.pl [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Małek, Łukasz A., E-mail: lmalek@ikard.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Mazurkiewicz, Łukasz, E-mail: lmazurkiewicz@ikard.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiomyopathy, Institute of Cardiology, Warsaw (Poland); Miłosz, Barbara, E-mail: barbara-milosz@o2.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Biernacka, Elżbieta K., E-mail: kbiernacka@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Kowalski, Mirosław, E-mail: mkowalski@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Hoffman, Piotr, E-mail: phoffman@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Demkow, Marcin, E-mail: mdemkow@ikard.pl [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Miśko, Jolanta, E-mail: jmisko@wp.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Rużyłło, Witold, E-mail: wruzyllo@ikard.pl [Institute of Cardiology, Warsaw (Poland)

2012-10-15

Background: Previous studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m{sup 2}). Methods: Consecutive patients with repaired tetralogy of Fallot were included (n = 53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance. Results: RVEDV was more closely correlated with PRV when compared with PRF (r = 0.686, p < 0.0001, and r = 0.430, p = 0.0014, respectively). On the other hand, both PRV and PRF showed a good correlation with the RV/LV ratio (r = 0.691, p < 0.0001, and r = 0.685, p < 0.0001, respectively). Receiver operating characteristic analysis showed that both measures of PR had similar ability to predict severe RV dilatation when the RV/LV ratio-based criterion was used, namely the RV/LV ratio > 2.0 [area under the curve (AUC){sub PRV} = 0.770 vs AUC{sub PRF} = 0.777, p = 0.86]. Conversely, with the use of the RVEDV-based criterion (>170 mL/m{sup 2}), PRV proved to be superior over PRF (AUC{sub PRV} = 0.770 vs AUC{sub PRF} = 0.656, p = 0.0028]. Conclusions: PRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV)

Comorbid forms of psychopathology: key patterns and future research directions.

Science.gov (United States)

Cerdá, Magdalena; Sagdeo, Aditi; Galea, Sandro

2008-01-01

The purpose of this review is to systematically appraise the peer-reviewed literature about clustered forms of psychopathology and to present a framework that can be useful for studying comorbid psychiatric disorders. The review focuses on four of the most prevalent types of mental health problems: anxiety, depression, conduct disorder, and substance abuse. The authors summarize existing empirical research on the distribution of concurrent and sequential comorbidity in children and adolescents and in adults, and they review existing knowledge about exogenous risk factors that influence comorbidity. The authors include articles that used a longitudinal study design and used psychiatric definitions of the disorders. A total of 58 articles met the inclusion criteria and were assessed. Current evidence demonstrates a reciprocal, sequential relation between most comorbid pairs, although the mechanisms that mediate such links remain to be explained. Methodological concerns include the inconsistency of measurement of the disorders across studies, small sample sizes, and restricted follow-up times. Given the significant mental health burden placed by comorbid disorders, and their high prevalence across populations, research on the key risk factors for clustering of psychopathology is needed.

Information retrieval models foundations and relationships

CERN Document Server

Roelleke, Thomas

2013-01-01

Information Retrieval (IR) models are a core component of IR research and IR systems. The past decade brought a consolidation of the family of IR models, which by 2000 consisted of relatively isolated views on TF-IDF (Term-Frequency times Inverse-Document-Frequency) as the weighting scheme in the vector-space model (VSM), the probabilistic relevance framework (PRF), the binary independence retrieval (BIR) model, BM25 (Best-Match Version 25, the main instantiation of the PRF/BIR), and language modelling (LM). Also, the early 2000s saw the arrival of divergence from randomness (DFR).Regarding in

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

Directory of Open Access Journals (Sweden)

Kavita Hotwani

2014-02-01

Full Text Available Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

Sheet of osteoblastic cells combined with platelet-rich fibrin improves the formation of bone in critical-size calvarial defects in rabbits.

Science.gov (United States)

Wang, Zhifa; Hu, Hanqing; Li, Zhijin; Weng, Yanming; Dai, Taiqiang; Zong, Chunlin; Liu, Yanpu; Liu, Bin

2016-04-01

Techniques that use sheets of cells have been successfully used in various types of tissue regeneration, and platelet-rich fibrin (PRF) can be used as a source of growth factors to promote angiogenesis. We have investigated the effects of the combination of PRF and sheets of mesenchymal stem cells (MSC) from bone marrow on the restoration of bone in critical-size calvarial defects in rabbits to find out whether the combination promotes bony healing. Sheets of MSC and PRF were prepared from the same donor. We then implanted the combined MSC and PRF in critical-size calvarial defects in rabbits and assessed bony restoration by microcomputed tomography (microCT) and histological analysis. The results showed that PRF significantly increased bony regeneration at 8 weeks after implantation of sheets of MSC and PRF compared with sheets of MSC alone (p=0.0048). Our results indicate that the combination of sheets of MSC and PRF increases bone regeneration in critical-size calvarial defects in rabbits, and provides a new way to improve skeletal healing. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Basics of case report form designing in clinical research

Directory of Open Access Journals (Sweden)

Shantala Bellary

2014-01-01

Full Text Available Case report form (CRF is a specialized document in clinical research. It should be study protocol driven, robust in content and have material to collect the study specific data. Though paper CRFs are still used largely, use of electronic CRFs (eCRFS are gaining popularity due to the advantages they offer such as improved data quality, online discrepancy management and faster database lock etc. Main objectives behind CRF development are preserving and maintaining quality and integrity of data. CRF design should be standardized to address the needs of all users such as investigator, site coordinator, study monitor, data entry personnel, medical coder and statistician. Data should be organized in a format that facilitates and simplifies data analysis. Collection of large amount of data will result in wasted resources in collecting and processing it and in many circumstances, will not be utilized for analysis. Apart from that, standard guidelines should be followed while designing the CRF. CRF completion manual should be provided to the site personnel to promote accurate data entry by them. These measures will result in reduced query generations and improved data integrity. It is recommended to establish and maintain a library of templates of standard CRF modules as they are time saving and cost-effective. This article is an attempt to describe the methods of CRF designing in clinical research and discusses the challenges encountered in this process.

Converting Topographic Maps into Digital Form to Aid in Archeological Research in the Peten, Guatemala

Science.gov (United States)

Aldrich, Serena R.

1999-01-01

The purpose of my project was to convert a topographical map into digital form so that the data can be manipulated and easily accessed in the field. With the data in this particular format, Dr. Sever and his colleagues can highlight the specific features of the landscape that they require for their research of the ancient Mayan civilization. Digital elevation models (DEMs) can also be created from the digitized contour features adding another dimension to their research.

Forming a Collaborative Action Research Partnership

Science.gov (United States)

Platteel, Tamara; Hulshof, Hans; Ponte, Petra; van Driel, Jan; Verloop, Nico

2010-01-01

This article describes the complex nature of collaborative relationships, the difficulties of conducting research with others, and the complications of partnerships in educational research. To create and sustain a communicative space in which participants can collaborate to innovate education and curriculum, time and opportunity to develop trust…

Integration of a Zero-footprint Cloud-based Picture Archiving and Communication System with Customizable Forms for Radiology Research and Education.

Science.gov (United States)

Hostetter, Jason; Khanna, Nishanth; Mandell, Jacob C

2018-06-01

The purpose of this study was to integrate web-based forms with a zero-footprint cloud-based Picture Archiving and Communication Systems (PACS) to create a tool of potential benefit to radiology research and education. Web-based forms were created with a front-end and back-end architecture utilizing common programming languages including Vue.js, Node.js and MongoDB, and integrated into an existing zero-footprint cloud-based PACS. The web-based forms application can be accessed in any modern internet browser on desktop or mobile devices and allows the creation of customizable forms consisting of a variety of questions types. Each form can be linked to an individual DICOM examination or a collection of DICOM examinations. Several uses are demonstrated through a series of case studies, including implementation of a research platform for multi-reader multi-case (MRMC) studies and other imaging research, and creation of an online Objective Structure Clinical Examination (OSCE) and an educational case file. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Doing Research, Doing Politics: ICT Research as a Form of Activism

Directory of Open Access Journals (Sweden)

Juliet Webster

2011-01-01

Full Text Available Why do we do research into ICTs and society at all?  Apart from advancing our analytical understanding of technological and social change, for many researchers, social studies of technology provide a way of supplying evidence for social policy, or shaping social practice.  Even if we do not always make it explicit, for many of us, our research is both political and personal.   In this paper, I consider the ways in which social and political values shape research questions and research methods.   Drawing on examples of recent feminist and other research which has investigated the employment relations of technological change, I discuss the academic and political ambitions of the work, the recognition of interests and the involvement of stakeholders, and the relationship between researchers and ‘users’ of the research.  I reflect on the importance of revealing and explicating the politics of ICT research, particularly in the context of imminent economic and social restructuring.

Radiofrequency therapy in back pain and complex regional pain syndrome (CRPS

Directory of Open Access Journals (Sweden)

Norina Bergamin

2011-01-01

Full Text Available Percutaneous radiofrequency procedures are frequently used in the management of chronic pain. Continuous radiofrequency (CRF has been established as a safe and effective treatment for pain originating from facet and sacroiliac joints by way of co-agulation of their nerve supply. Different methods have been proposed to account for the complex nerve supply of the sacroiliac joint. Due to its neurodestructive property, CRF was limited to the treatment of neuropathic pain. When applied to the dorsal root ganglion (DRG for spinal pain or to the sympathetic ganglia in treatment of CRPS, heat related side effects have been reported. With the development of pulsed radiofrequency (PRF, a less destructive alternative to CRF became available, that is more suitable to treat neuropathic pain. PRF was adopted in the treatment of several pain conditions with different success. The results with PRF adjacent to the DRG are promising, whereas for facet and sacroiliac joint pain PRF could not yet be proven equally effective as CRF. As for PRF in CRPS there is almost no evidence available. The potential of PRF seems to lie in those areas where CRF is of limited value. Con-versely, it is questionable if PRF will ever be equally effective in indications, where CRF is already well established. Despite its active use in clinical practice, PRF is not validated yet nor is its mode of action. The literature in both cases is accumulating but further studies are urgently needed.

Impact of preoperative calculation of nephron volume loss on future of partial nephrectomy techniques; planning a strategic roadmap for improving functional preservation and securing oncological safety.

Science.gov (United States)

Rha, Koon H; Abdel Raheem, Ali; Park, Sung Y; Kim, Kwang H; Kim, Hyung J; Koo, Kyo C; Choi, Young D; Jung, Byung H; Lee, Sang K; Lee, Won K; Krishnan, Jayram; Shin, Tae Y; Cho, Jin-Seon

2017-11-01

To assess the correlation of the resected and ischaemic volume (RAIV), which is a preoperatively calculated volume of nephron loss, with the amount of postoperative renal function (PRF) decline after minimally invasive partial nephrectomy (PN) in a multi-institutional dataset. We identified 348 patients from March 2005 to December 2013 at six institutions. Data on all cases of laparoscopic (n = 85) and robot-assisted PN (n = 263) performed were retrospectively gathered. Univariable and multivariable linear regression analyses were used to identify the associations between various time points of PRF and the RAIV, as a continuous variable. The mean (sd) RAIV was 24.2 (29.2) cm 3 . The mean preoperative estimated glomerular filtration rate (eGFR) and the eGFRs at postoperative day 1, 6 and 36 months after PN were 91.0 and 76.8, 80.2 and 87.7 mL/min/1.73 m 2 , respectively. In multivariable linear regression analysis, the amount of decline in PRF at follow-up was significantly correlated with the RAIV (β 0.261, 0.165, 0.260 at postoperative day 1, 6 and 36 months after PN, respectively). This study has the limitation of its retrospective nature. Preoperatively calculated RAIV significantly correlates with the amount of decline in PRF during long-term follow-up. The RAIV could lead our research to the level of prediction of the amount of PRF decline after PN and thus would be appropriate for assessing the technical advantages of emerging techniques. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Effects of platelet-rich fibrin and piezosurgery on impacted mandibular third molar surgery outcomes.

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Uyanık, Lokman Onur; Bilginaylar, Kani; Etikan, İlker

2015-07-26

The aim of this study was the comparision of postoperative outcomes in impacted mandibular third molars that were treated using either platelet-rich fibrin (PRF), a combination of PRF and piezosurgery, or conventional rotatory osteotomy. The study included 20 patients; 40 extractions of impacted mandibular third molars were performed. Patients were divided into two main groups. In group A (n = 20), traditional surgery was performed on one side (Group 1, n = 10); traditional surgery was performed, and PRF was administered to the extracted socket on the other side of same patient (Group 2, n = 10). In group B (n = 20), on one side, piezosurgery was used for osteotomy, and PRF was administered (Group 3, n = 10); on the other side of same patient, traditional surgery was performed (Group 4, n = 10). Parameters assessed at baseline for each patient included pain, the number of analgesics taken, trismus, and cheek swelling. These variables were also assessed on postoperative days 1, 2, 3, and 7. Statistical analysis revealed a significant reduction in postoperative pain (sum of 1(st), 2(nd), 3(rd) and 7(th) days) and trismus (on postoperative day 1) in group 2 (traditional surgery + PRF group), and in postoperative pain, the number of analgesics taken (sum of 1(st), 2(nd),3(rd) and 7(th) days) and trismus (on postoperative day 1) in group 3 (piezosurgery + PRF group) compared to groups 1 and 4 (traditional surgery groups), (p ≤ 0.05). However, swelling on postoperative days 1, 3, and 7 did not differ among the groups (p > 0.05). Only difference was on second day between groups 1-4 and 2-4 (p ≤ 0.05). The results of our study have shown that the use of PRF with traditional surgery and PRF combined with piezosurgery significantly reduced pain during the postoperative period. In addition, PRF in combination with piezosurgery significantly decreased the number of analgesics taken. Both operations also significantly decreased

Biomimicry of Palm Tree Leaves Form and Pattern on Building Form

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Agus Salim N.A.

2014-01-01

Full Text Available This article is a study on biomimicry of palm tree towards a building form. It is to find a suitable form and pattern that can be applied to building shell to ease building maintenance operation beside to enhance the aesthetic value of a building architecture. The research has been carried out by observation and modeling on some various species of palm tree’s patterns and forms. The result expectation can be found at the end of this research by producing the best pattern of palm tree that can be adapted to building envelop as the whole form of a building.

Magnesium-enhanced enzymatically mineralized platelet-rich fibrin for bone regeneration applications

International Nuclear Information System (INIS)

Gassling, Volker; Purcz, Nicolai; Douglas, Timothy E L; Dubruel, Peter; Schaubroeck, David; Balcaen, Lieve; Vanhaecke, Frank; Bliznuk, Vitaliy; Declercq, Heidi A

2013-01-01

Membranes of the autologous blood-derived biomaterial platelet-rich fibrin (PRF) were mineralized enzymatically with calcium phosphate (CaP) by the incorporation of alkaline phosphatase (ALP) followed by incubation for 3 days in solutions of either 0.1 M calcium glycerophosphate (CaGP) or a combination of CaGP and magnesium glycerophosphate (CaGP:MgGP; both 0.05 M), resulting in the formation of two different PRF-mineral composites. Fourier transform infrared spectroscopy, transmission electron microscopy and selected area electron diffraction examinations showed that the CaP formed was amorphous. Inductively coupled plasma optical emission spectroscopy analysis revealed similar amounts of Ca and P in both composite types, while a smaller amount of Mg (Ca:Mg molar ratio = 10) was detected in the composites formed in the CaGP:MgGP solution, which was supported by the results of energy-dispersive x-ray spectroscopy-based elemental mapping. Scanning electron microscopy (SEM) imaging showed that the mineral deposits in PRF incubated in the CaGP:MgGP solution were markedly smaller. The mass percentage attributable to the mineral phase was similar in both composite types. MTT and WST tests with SAOS-2 cells revealed that incubation in the CaGP:MgGP solution had no negative effect on cytocompatibility and cell proliferation compared to the CaGP solution. Cells on all samples displayed a well-spread morphology as revealed by SEM imaging. In conclusion, the incorporation of Mg reduces mineral deposit dimensions and promotes cell proliferation. (paper)

Micro-computed tomography and histomorphometric analysis of the effects of platelet-rich fibrin on bone regeneration in the rabbit calvarium.

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Acar, Ahmet Hüseyin; Yolcu, Ümit; Gül, Mehmet; Keleş, Ali; Erdem, Necip Fazıl; Altundag Kahraman, Sevil

2015-04-01

The present study aimed to investigate the effectiveness of platelet-rich fibrin (PRF) on bone regeneration when used alone or in combination with hydroxyapatite (HA)/beta-tricalcium phosphate (βTCP). In this study, 20 New Zealand white rabbits were used and four calvarial defects were prepared in each animal. PRF, Straumann(®) Bone Ceramic (SBC), or PRF+SBC was applied to the defects; one defect was left untreated as a control. Ten rabbits were sacrificed at week 4 (T1) and 10 at week 8 (T2). After micro-computed tomography (micro-CT) scanning, the samples were sent for histological and histomorphometric analysis to evaluate and compare the volume and area of regenerated bone. Histomorphometric and micro-CT analysis showed that both PRF and SBC significantly increased bone regeneration at T1 and T2 (P<0.01). When PRF was used in combination with HA/βTCP, a further significant increase in new bone formation was observed at T1 and T2 compared with that when PRF or SBC was used alone (P<0.01). PRF has a positive effect on bone formation when used alone and in combination with HA/βTCP. Copyright © 2014 Elsevier Ltd. All rights reserved.

Platelet-Rich Fibrin Accelerates Skin Wound Healing in Diabetic Mice.

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Ding, Yinjia; Cui, Lei; Zhao, Qiming; Zhang, Weiqiang; Sun, Huafeng; Zheng, Lijun

2017-09-01

Diabetic foot ulcers (DFUs) are associated with an increased risk of secondary infection and amputation. Platelet-rich fibrin (PRF), a platelet and leukocyte concentrate containing several cytokines and growth factors, is known to promote wound healing. However, the effect of PRF on diabetic wound healing has not been adequately investigated. The aim of the study was to investigate the effect of PRF on skin wound healing in a diabetic mouse model. Platelet-rich fibrin was prepared from whole blood of 8 healthy volunteers. Two symmetrical skin wounds per mouse were created on the back of 16 diabetic nude mice. One of the 2 wounds in each mouse was treated with routine dressings (control), whereas the other wound was treated with PRF in addition to routine dressings (test), each for a period of 14 days. Skin wound healing rate was calculated.Use of PRF was associated with significantly improved skin wound healing in diabetic mice. On hematoxylin and eosin and CD31 staining, a significant increase in the number of capillaries and CD31-positive cells was observed, suggesting that PRF may have promoted blood vessel formation in the skin wound. In this study, PRF seemed to accelerate skin wound healing in diabetic mouse models, probably via increased blood vessel formation.

The Synergistic Effect of Leukocyte Platelet-Rich Fibrin and Micrometer/Nanometer Surface Texturing on Bone Healing around Immediately Placed Implants: An Experimental Study in Dogs

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Neiva, Rodrigo F.; Gil, Luiz Fernando; Tovar, Nick; Janal, Malvin N.; Marao, Heloisa Fonseca; Pinto, Nelson; Coelho, Paulo G.

2016-01-01

Aims. This study evaluated the effects of L-PRF presence and implant surface texture on bone healing around immediately placed implants. Methods. The first mandibular molars of 8 beagle dogs were bilaterally extracted, and implants (Blossom™, Intra-Lock International, Boca Raton, FL) were placed in the mesial or distal extraction sockets in an interpolated fashion per animal. Two implant surfaces were distributed per sockets: (1) dual acid-etched (DAE, micrometer scale textured) and (2) micrometer/nanometer scale textured (Ossean™ surface). L-PRF (Intraspin system, Intra-Lock International) was placed in a split-mouth design to fill the macrogap between implant and socket walls on one side of the mandible. The contralateral side received implants without L-PRF. A mixed-model ANOVA (at α = 0.05) evaluated the effect of implant surface, presence of L-PRF, and socket position (mesial or distal), individually or in combination on bone area fraction occupancy (BAFO). Results. BAFO values were significantly higher for the Ossean relative to the DAE surface on the larger mesial socket. The presence of L-PRF resulted in higher BAFO. The Ossean surface and L-PRF presence resulted in significantly higher BAFO. Conclusion. L-PRF and the micro-/nanometer scale textured surface resulted in increased bone formation around immediately placed implants. PMID:28042577

The Synergistic Effect of Leukocyte Platelet-Rich Fibrin and Micrometer/Nanometer Surface Texturing on Bone Healing around Immediately Placed Implants: An Experimental Study in Dogs

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Rodrigo F. Neiva

2016-01-01

Full Text Available Aims. This study evaluated the effects of L-PRF presence and implant surface texture on bone healing around immediately placed implants. Methods. The first mandibular molars of 8 beagle dogs were bilaterally extracted, and implants (Blossom™, Intra-Lock International, Boca Raton, FL were placed in the mesial or distal extraction sockets in an interpolated fashion per animal. Two implant surfaces were distributed per sockets: (1 dual acid-etched (DAE, micrometer scale textured and (2 micrometer/nanometer scale textured (Ossean™ surface. L-PRF (Intraspin system, Intra-Lock International was placed in a split-mouth design to fill the macrogap between implant and socket walls on one side of the mandible. The contralateral side received implants without L-PRF. A mixed-model ANOVA (at α=0.05 evaluated the effect of implant surface, presence of L-PRF, and socket position (mesial or distal, individually or in combination on bone area fraction occupancy (BAFO. Results. BAFO values were significantly higher for the Ossean relative to the DAE surface on the larger mesial socket. The presence of L-PRF resulted in higher BAFO. The Ossean surface and L-PRF presence resulted in significantly higher BAFO. Conclusion. L-PRF and the micro-/nanometer scale textured surface resulted in increased bone formation around immediately placed implants.

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

International Nuclear Information System (INIS)

Pérez, Juan J.; Pérez-Cajaraville, Juan J.; Muñoz, Víctor; Berjano, Enrique

2014-01-01

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m −1 ) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal

Pulsed radiofrequency treatment of articular branches of femoral and obturator nerves for chronic hip pain

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Chye CL

2015-03-01

Full Text Available Cien-Leong Chye,1 Cheng-Loong Liang,1 Kang Lu,1 Ya-Wen Chen,2,3 Po-Chou Liliang1 1Department of Neurosurgery, E-Da Hospital, I-Shou University, 2Department of Nursing, I-Shou University, 3School of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan Purpose: Chronic hip pain is a common symptom experienced by many people. Often, surgery is not an option for patients with multiple comorbidities, and conventional drugs either have many side effects or are ineffective. Pulsed radiofrequency (PRF is a new method in the treatment of pain. We attempt to compare the efficacy of PRF relative to conservative management for chronic hip pain.Patients and methods: Between August 2011 and July 2013, 29 patients with chronic hip pain were divided into two groups (PRF and conservative treatment according to consent or refusal to undergo PRF procedure. Fifteen patients received PRF of the articular branches of the femoral and obturator nerves, and 14 patients received conservative treatment. Visual analog scale (VAS, Oxford hip scores (OHS, and pain medications were used for outcome measurement before treatment and at 1 week, 4 weeks, and 12 weeks after treatment.Results: At 1 week, 4 weeks, and 12 weeks after treatment initiation, improvements in VAS were significantly greater with PRF. Improvements in OHS were significantly greater in the PRF group at 1 week, 4 weeks, and 12 weeks. Patients in the PRF group also used less pain medications. Eight subjects in the conservative treatment group switched to the PRF group after 12 weeks, and six of them had >50% improvement.Conclusion: When compared with conservative treatment, PRF of the articular branches of the femoral and obturator nerves offers greater pain relief for chronic hip pain and can augment physical functioning. Keywords: pulsed radiofrequency, obturator and femoral nerves, hip joint pain, osteoar­thritis

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

Energy Technology Data Exchange (ETDEWEB)

Pérez, Juan J. [Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada al Ser Humano, Universitat Politècnica de València, Valencia 46022 (Spain); Pérez-Cajaraville, Juan J. [Pain Unit and Department of Anesthesia and Critical Care, Clínica Universidad de Navarra, University of Navarra, Pamplona 31008 (Spain); Muñoz, Víctor [Neurotherm Spain, Barcelona 08303 (Spain); Berjano, Enrique, E-mail: eberjano@eln.upv.es [Biomedical Synergy, Electronic Engineering Department, Universitat Politècnica de València 46022 (Spain)

2014-07-15

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m{sup −1}) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief.

Science.gov (United States)

Pérez, Juan J; Pérez-Cajaraville, Juan J; Muñoz, Víctor; Berjano, Enrique

2014-07-01

Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a "strip lesion" to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m(-1)) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal damage zone dimension.

Studies of high-level radioactive waste form performance at Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

Banba, Tsunetaka; Kamizono, Hiroshi; Mitamura, Hisayoshi

1992-02-01

The recent studies of high-level radioactive waste form at Japan Atomic Energy Research Institute can be classified into the following three categories; (1) Study on the leaching behavior of the nuclear waste glass placing the focus on the alteration layer and the chemical composition of leachant for the prediction of the long-term corrosion of the waste glass. (2) Study on the radiation (alpha-radiation) effects which have relation to the long-term stability of the nuclear waste glass. (3) Study on the long-term self-irradiation damage of a SYNROC waste form using a curium-doped sample. In the present report, the recent results corresponding to the above categories are described. (author)

Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth.

Science.gov (United States)

Wang, Qi Lin; Yang, Pan Pan; Ge, Li Hong; Liu, He

2016-03-01

To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth. Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks. The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex. Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

Overview of JSPS Core-to-Core Program: Forming Research and Educational Hubs of Medical Physics.

Science.gov (United States)

Koizumi, Masahiko; Takashina, Masaaki

To foster medical physicists, we introduce the achievement we made since 2011 under the national research project of the Japan Society for the Promotion of Science (JSPS) Core-to-Core program; 'Forming Research and Educational Hubs of Medical Physics.' On this basis and under the JSPS program, we promoted research and educational exchange with Indiana University (IU) in USA, University of Groningen (The UG) in the Netherland and other cooperating institutions such as University of Minnesota (UM).A total of 23 students and researchers were sent. UG accepted the most among three institutions. In turn, 12 foreign researchers including post-doctor fellows came to Japan for academic seminars or educational lectures.Fifteen international seminars were held; 8 in Japan, 4 in USA, and 3 in the Netherland.Lots of achievement were made through these activities in 5 years. Total of 23 research topics at the international conferences were presented. Total of 12 articles were published in international journals.This program clearly promoted the establishment of international collaboration, and many young researchers and graduate students were exchanged and collaborated with foreign researchers.

Prevention of Localized Osteitis in Mandibular Third-Molar Sites Using Platelet-Rich Fibrin

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Donald R. Hoaglin

2013-01-01

Full Text Available Purpose. To review our experience utilizing platelet rich fibrin (PRF, which is reported to aid in wound healing of extraction sites, for the prevention of localized osteitis following lower third-molar removal. Materials and Methods. PRF was placed in the mandibular third-molar extraction sites, 200 sites total, on 100 consecutive patients treated in our practice, by the authors. The patients were managed with standard surgical techniques, intraoperative IV antibiotic/steroid coverage, and routine postoperative narcotic analgesics/short-term steroid coverage. All patients were reevaluated for localized osteitis within 7–10 days of the surgery. A comparison group consisted of 100 consecutive patients who underwent bilateral removal of indicated mandibular wisdom teeth and did not receive PRF placement within the lower third molar surgical sites. Results. The incidence of localized osteitis (LO following removal of 200 lower third molars with simultaneous PRF placement within the extraction site was 1% (2 sites out of 200. The group of patients whose mandibular 3rd molar sockets were not treated with PRF demonstrated a 9.5% (19 sites out of 200 incidence of localized osteitis. The latter group also required 6.5 hours of additional clinical time to manage LO than the study group who received PRF. Conclusions. This retrospective review demonstrated that preventative treatment of localized osteitis can be accomplished using a low cost, autogenous, soluble, biologic material, PRF, that PRF enhanced third-molar socket healing/clot retention and greatly decreased the clinical time required for postoperative management of LO.

Does the Addition of Bone Morphogenetic Protein 2 to Platelet-Rich Fibrin Improve Healing After Treatment for Medication-Related Osteonecrosis of the Jaw?

Science.gov (United States)

Park, Jung-Hyun; Kim, Jin-Woo; Kim, Sun-Jong

2017-06-01

To investigate the effect of the addition of bone morphogenetic protein 2 (BMP-2) to leukocyte-rich and platelet-rich fibrin (L-PRF) on the treatment of medication-related osteonecrosis of the jaws (MRONJ), this study compared the healing outcome of combined use of BMP-2 and L-PRF with single use of L-PRF. Of 55 patients who were diagnosed with MRONJ, 25 were treated with L-PRF alone and 30 were treated with L-PRF and recombinant human BMP-2. For each patient, surgical sites were evaluated postoperatively at 4 and 16 weeks. Associations between the treatment method and the resolution of MRONJ were analyzed with the adjustment of patient-specific factors that may influence the treatment outcome. At 4 and 16 weeks postoperatively, patients with MRONJ who were treated with both L-PRF and BMP-2 showed favorable outcomes with complete resolution of the lesions, which was statistically significant compared with that of the therapy using L-PRF alone (P = .028). Therefore, the additional use of BMP-2 considerably improved MRONJ healing. Among patient-specific factors, the existence of a bacterial colony in the biopsy specimen was a significant factor that negatively affected disease resolution (P = .017). The combined use of BMP-2 and L-PRF leads to the early resolution of MRONJ; thus patients who need to continue antiresorptive therapy may benefit from the combined regimen. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

A comparative study of the regenerative effect of sinus bone grafting with platelet-rich fibrin-mixed Bio-Oss® and commercial fibrin-mixed Bio-Oss®: an experimental study.

Science.gov (United States)

Xuan, Feng; Lee, Chun-Ui; Son, Jeong-Seog; Jeong, Seung-Mi; Choi, Byung-Ho

2014-06-01

Anorganic bovine bone (Bio-Oss®) particles are one of the most popular grafting materials. The particles are often mixed with platelet-rich fibrin (PRF) or a commercial fibrin (Tisseel®) to form a mouldable graft material. The objective of this study was to compare the potentials of PRF-mixed Bio-Oss® and Tisseel®-mixed Bio-Oss® to enhance bone regeneration in a canine sinus model. Six mongrel dogs were used in this study. After elevating the sinus membrane in both maxillary sinus cavities, an implant was placed into the sinus cavity. In one of the sinus cavities, the PRF/Bio-Oss® composite was grafted, and the Tisseel®/Bio-Oss® composite was grafted in the other sinus cavity. After a 6 month healing period, bone formation in the graft sites and bone-implant contact were evaluated. The mean osseointegration rate was 43.5 ± 12.4% and new bone formation rate 41.8 ± 5.9% in the PRF/Bio-Oss® composite sites. In the Tisseel®/Bio-Oss® composite sites they were 30.7 ± 7.9% and 31.3 ± 6.4%. There were statistically significant differences between the groups. The findings from this study suggest that when platelet-rich fibrin is used as an adjunct to Bio-Oss® particles for bone augmentation in the maxillary sinus, bone formation in the graft sites is significantly greater than when Tisseel® is used. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Research approach for forming a new typology of spatial planning theory

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Bulajić Vladan

2011-01-01

Full Text Available What is being suggested in this paper is the research approach for the classification of theoretical contributions in the scientific domain of the spatial planning. Typology is a multidimensional classification, actually it is the framework for the understanding of the subject area, theory and practice, ideas and methodologies. The complex approach is needed to organize the complex and diverse domain of spatial planning theory, which has been shaped by different schools of thought and the influences of the related scientific disciplines. It has been suggested that the research approach becomes the bridge between two cultures, in other words it should be the synthesis of the qualitative and quantitative methods of the typology construction. With the analysis of the existing typologies, which are quantitatively derived, the chosen concepts will be improved and completed due to the computerized statistical analysis of the appropriate bibliometrical data. Moreover, the procedure in the opposite direction will be used, which also connects empiric types with their conceptual counterparts. With that approach, the main aim is to achieve the comprehensive classification scheme, which will take part of the platform for integration of the interdisciplinary approach in the spatial planning domain. That concept of the research belongs to the wider approach that has got the aim that with the scientific innovations and imaginations bring about the solving of the problems and challenges that the spatial planning faces with. The forming of the new typology is the first step in that direction.

Quantitative assessment of right ventricular function and pulmonary regurgitation in surgically repaired tetralogy of Fallot using 256-slice CT: comparison with 3-Tesla MRI

Energy Technology Data Exchange (ETDEWEB)

Yamasaki, Yuzo; Yonezawa, Masato; Matsuo, Yoshio; Kamitani, Takeshi; Higuchi, Ko; Honda, Hiroshi [Graduate School of Medical Sciences, Kyushu University, Department of Clinical Radiology, Higashi-ku, Fukuoka (Japan); Nagao, Michinobu; Kawanami, Satoshi [Graduate School of Medical Sciences, Kyushu University, Department of Molecular Imaging and Diagnosis, Higashi-ku, Fukuoka (Japan); Yamamura, Kenichiro [Graduate School of Medical Sciences, Kyushu University, Department of Pediatrics, Higashi-ku, Fukuoka (Japan); Sakamoto, Ichiro [Graduate School of Medical Sciences, Kyushu University, Department of Cardiovascular Medicine, Higashi-ku, Fukuoka (Japan); Shiokawa, Yuichi [Graduate School of Medical Sciences, Kyushu University, Department of Cardiovascular Surgery, Higashi-ku, Fukuoka (Japan); Yabuuchi, Hidetake [Graduate School of Medical Sciences, Kyushu University, Department of Health Sciences, Higashi-ku, Fukuoka (Japan)

2014-12-15

To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF). Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV - LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability. CCT measurements, including PRF, correlated highly with the CMR reference (r = 0.71-0.96). CCT overestimated RVEDV (mean difference, 17.1 ± 2.9 ml), RVESV (12.9 ± 2.1 ml) and RVSV (4.2 ± 2.0 ml), and underestimated RVEF (-2.6 ± 1.0 %) and PRF (-9.1 ± 2.0 %) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6 ± 2.6 mSv. 256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF. (orig.)

THE KEPLER PIXEL RESPONSE FUNCTION

International Nuclear Information System (INIS)

Bryson, Stephen T.; Haas, Michael R.; Dotson, Jessie L.; Koch, David G.; Borucki, William J.; Tenenbaum, Peter; Jenkins, Jon M.; Chandrasekaran, Hema; Caldwell, Douglas A.; Klaus, Todd; Gilliland, Ronald L.

2010-01-01

Kepler seeks to detect sequences of transits of Earth-size exoplanets orbiting solar-like stars. Such transit signals are on the order of 100 ppm. The high photometric precision demanded by Kepler requires detailed knowledge of how the Kepler pixels respond to starlight during a nominal observation. This information is provided by the Kepler pixel response function (PRF), defined as the composite of Kepler's optical point-spread function, integrated spacecraft pointing jitter during a nominal cadence and other systematic effects. To provide sub-pixel resolution, the PRF is represented as a piecewise-continuous polynomial on a sub-pixel mesh. This continuous representation allows the prediction of a star's flux value on any pixel given the star's pixel position. The advantages and difficulties of this polynomial representation are discussed, including characterization of spatial variation in the PRF and the smoothing of discontinuities between sub-pixel polynomial patches. On-orbit super-resolution measurements of the PRF across the Kepler field of view are described. Two uses of the PRF are presented: the selection of pixels for each star that maximizes the photometric signal-to-noise ratio for that star, and PRF-fitted centroids which provide robust and accurate stellar positions on the CCD, primarily used for attitude and plate scale tracking. Good knowledge of the PRF has been a critical component for the successful collection of high-precision photometry by Kepler.

Influence of the association between platelet-rich fibrin and bovine bone on bone regeneration. A histomorphometric study in the calvaria of rats.

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Oliveira, M R; deC Silva, A; Ferreira, S; Avelino, C C; Garcia, I R; Mariano, R C

2015-05-01

This study aimed to investigate the effects of platelet-rich fibrin (PRF) associated or not with Bio-Oss on bone defects in the calvaria of rats. A critical-size defect of 5-mm diameter was performed in the calvaria of 48 rats. These animals were divided into six groups of eight animals each, according to the treatment received: homogeneous clot, autogenous clot, autogenous PRF, homogeneous PRF, Bio-Oss, or Bio-Oss associated with PRF. The animals were euthanized after 30 or 60 days. Bone regeneration was evaluated by histomorphometric analysis. The highest mean percentages of new bone formation at 30 days (54.05% ± 5.78) and 60 days (63.58% ± 5.78) were observed in the Bio-Oss associated with PRF group; in particular, the percentage of new bone at 30 days was significantly higher than that of all of the other groups (P<0.01). At 60 days, the Bio-Oss associated with PRF (63.58% ± 5.78) and Bio-Oss (57.34% ± 5.78) groups had similar results, and both showed a statistical difference compared to the other groups. PRF had a positive effect on bone regeneration only when associated with Bio-Oss. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Quantitative assessment of right ventricular function and pulmonary regurgitation in surgically repaired tetralogy of Fallot using 256-slice CT: comparison with 3-Tesla MRI

International Nuclear Information System (INIS)

Yamasaki, Yuzo; Yonezawa, Masato; Matsuo, Yoshio; Kamitani, Takeshi; Higuchi, Ko; Honda, Hiroshi; Nagao, Michinobu; Kawanami, Satoshi; Yamamura, Kenichiro; Sakamoto, Ichiro; Shiokawa, Yuichi; Yabuuchi, Hidetake

2014-01-01

To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF). Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV - LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability. CCT measurements, including PRF, correlated highly with the CMR reference (r = 0.71-0.96). CCT overestimated RVEDV (mean difference, 17.1 ± 2.9 ml), RVESV (12.9 ± 2.1 ml) and RVSV (4.2 ± 2.0 ml), and underestimated RVEF (-2.6 ± 1.0 %) and PRF (-9.1 ± 2.0 %) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6 ± 2.6 mSv. 256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF. (orig.)

ASSESSMENT FORM - NEW IMPROVEMENT OF ACTIONS: CONCENTRATION AND RESEARCH AREAS / CURRICULUM STRUCTURE / FUNDRAISING

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Iracema MP Calderon

Full Text Available Objective: This review aims to develop a critical and current analysis of the basic structure of a Postgraduate program for proposing improvement actions and new evaluation criteria. Method: To examine the items that are areas of concentration (AC, research lines (LP, research projects (PP, curricular structure and fundraising were consulted the Area Document, the 2013 Evaluation Report and the Assessment Sheets of Medicine III programs, evaluated in the 2010-2012 period. Results: Consistency is recommended especially among AC, LP and PP, with genuine link between activities and permanent teachers skills and based on structured curriculum in the education of the student. The Program Proposal interfere, and much, in qualifying a program. The curriculum should provide subsidy to the formation of the researcher, through the core subjects, and development of PP, being the concept of disciplines to support lines and research projects. Fundraise should be set out in research projects and in the CV-Lattes. The area recommended that at least 40-50% of permanent teachers present fundraising and the minimum 20-25% of these teachers to have productivity scholarship PQ / CNPq during the triennium. Conclusion: It is necessary to promote wide discussion and find a consensus denominator for these issues. The actions should contribute to the improvement of evaluation forms and certainly for the qualification of the programs but graduate.

Studies of glass waste form performance at Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

Banba, Tsunetaka; Kamizono, Hiroshi; Nakayama, Shinichi; Tashiro, Shingo

1989-08-01

The recent studies of glass waste form performance at Japan Atomic Energy Research Institute can be classified into the following three categories; (1) Study on the volatilization of radionuclides from the waste glass, which is necessary to estimate the safety in relation to operation of a storage facility. (2) Study on the radiation (alpha-radiation) effects which have relation to the long-term stability of the waste glass. (3) Study on the leaching behavior of actinides under the repository conditions, which is necessary to predict the long-term release rate of radionuclides from the waste glass. In the present report, the recent results corresponding to the above categories are described. (author)

Effects of platelet-poor plasma, platelet-rich plasma, and platelet-rich fibrin on healing of extraction sockets with buccal dehiscence in dogs.

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Hatakeyama, Ichiro; Marukawa, Eriko; Takahashi, Yukinobu; Omura, Ken

2014-02-01

Alveolar bone resorption generally occurs during healing after tooth extraction. This study aimed to evaluate the effects of platelet-poor plasma (PPP), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) on healing in a ridge-augmentation model of the canine socket with dehiscence of the buccal wall. The third mandibular premolars of 12 beagle dogs were extracted and a 3 mm buccal dehiscence from the alveolar crest to the buccal wall of the extraction socket was created. These sockets were then divided into four groups on the basis of the material used to fill the sockets: PPP, PRP, PRF, and control (no graft material) groups. Results were evaluated at 4 and 8 weeks after surgery. The ultrastructural morphology and constructs of each blood product were studied by a scanning electron microscope (SEM) or calculating concentrations of platelets, fibrinogen, platelet-derived growth factor, and transforming growth factor-β. A total of five microcomputed tomography images of specimens were selected for measurement, and the area occupied by the newly formed bone as well as the horizontal bone width were measured. Moreover, decalcified tissue specimens from each defect were analyzed histologically. The median area of new bone at 4 and 8 weeks and median horizontal bone width at 8 weeks were the highest in the PPP group. However, bone maturation in the PRF and the PRP groups was more progressed than that in the PPP and control groups. By SEM findings, the PRF group showed a more highly condensed fibrin fiber network that was regularly arranged when compared with the PPP and PRP groups. The growth factors released from platelets in PRP indicated higher concentrations than that in PRF. Under more severe conditions for bone formation, as in this experiment, the growth factors released from platelets had a negative effect on bone formation. This study showed that PPP is an effective material for the preservation of sockets with buccal dehiscence.

Research of Academic Motivation at the Stage of Forming a Threshold Level of Mastering Competences

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Eremicheva, Oksana Y.; Yudin, Vladimir V.; Sheptukhina, Inna I.; Zyryanova, Natalia I.; Shevchenko, Valery Y.; Komarova, Yuliya G.; Simonova, Marina V.

2016-01-01

The relevance of the researched problem is caused by the society requirement to form and implement educational and creative potential of a student as a conductor of changes that set a high level of motivational behavior. The aim of this article is to develop a structural model of motivational behavior of students that allow carrying out modeling…

Research on Thermal-Field and Sound-Field Coupling Properties of Different Grid Forms

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Enlai Zhang

2016-01-01

Full Text Available The inlet grid and exhaust grid are widely used in engineering machinery products. The process that airflow goes through grids is a complex turbulent flow and directly related to the heat dispersion and aerodynamic noise. The theoretical analysis result shows that the jet noise generated by airflow has a connection with the grid structure form, fluid flowing situation, and heat conduction. In addition, the influences of different grid structure forms (included the round hole, long hole, and square hole and porosity on the heat dissipation and aerodynamic noise were analyzed and presented based on the verified computational fluid dynamics (CFD model. Results show that the heat dispersion and aerodynamic noise of the round hole are most effective under the same porosity; as the porosity increases, the disturbance degree decreases and the noise reduction effect gets better. Finally, the research result provides the scientific basis for improving grid structure and achieving energy saving and noise reduction.

Cortical depth dependent population receptive field attraction by spatial attention in human V1.

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Klein, Barrie P; Fracasso, Alessio; van Dijk, Jelle A; Paffen, Chris L E; Te Pas, Susan F; Dumoulin, Serge O

2018-04-27

Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could underlie pRF attraction in a given cortical area. Here, we use sub-millimeter ultra-high field functional MRI to measure pRF attraction across cortical depth and assess the contribution of feed forward and feedback signals to pRF attraction. In line with previous findings, we find consistent attraction of pRFs with voluntary spatial attention in V1. When assessed as a function of cortical depth, we find pRF attraction in every cortical portion (deep, center and superficial), although the attraction is strongest in deep cortical portions (near the gray-white matter boundary). Following the organization of feed forward and feedback processing across V1, we speculate that a mixture of feed forward and feedback processing underlies pRF attraction in V1. Specifically, we propose that feedback processing contributes to the pRF attraction in deep cortical portions. Copyright © 2018. Published by Elsevier Inc.

Management of radicular cysts using platelet-rich fibrin and bioactive glass: a report of two cases.

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Zhao, Jiing-Huei; Tsai, Chung-Hung; Chang, Yu-Chao

2014-07-01

Platelet-rich fibrin (PRF) created by Choukroun's protocol concentrates most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. However, no current data is available concerning the use of PRF for the treatment of periapical lesions. Two cases of radicular cysts were reported using an interdisciplinary approach, including regular endodontic therapy followed by surgical management with PRF and bioactive glass. Two cases of radicular cysts presented as an incidental radiographic finding, appearing as an apical radiolucency with well-circumscribed sclerotic borders. After regular endodontic retreatment, cystic lining/granulation tissues were enucleated and the periradicular bony defect was grafted using PRF and bioactive glass. Then, PRF was applied to serve as a membrane over the grafted defects. Recall periapical radiographs of Case 1 and cone beam computer tomography of Case 2 showed satisfactory healing of the periapical pathosis. In Case 2, the bony defect appeared completely healed at 4 months surgical reentry and the new bone was clinically very dense and mature. The results of these case reports show that the combination of PRF and bioactive glass is an effective modality of regenerative treatment for radicular cysts. Copyright © 2012. Published by Elsevier B.V.

Management of radicular cysts using platelet-rich fibrin and bioactive glass: A report of two cases

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Jiing-Huei Zhao

2014-07-01

Full Text Available Platelet-rich fibrin (PRF created by Choukroun’s protocol concentrates most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. However, no current data is available concerning the use of PRF for the treatment of periapical lesions. Two cases of radicular cysts were reported using an interdisciplinary approach, including regular endodontic therapy followed by surgical management with PRF and bioactive glass. Two cases of radicular cysts presented as an incidental radiographic finding, appearing as an apical radiolucency with well-circumscribed sclerotic borders. After regular endodontic retreatment, cystic lining/granulation tissues were enucleated and the periradicular bony defect was grafted using PRF and bioactive glass. Then, PRF was applied to serve as a membrane over the grafted defects. Recall periapical radiographs of Case 1 and cone beam computer tomography of Case 2 showed satisfactory healing of the periapical pathosis. In Case 2, the bony defect appeared completely healed at 4 months surgical reentry and the new bone was clinically very dense and mature. The results of these case reports show that the combination of PRF and bioactive glass is an effective modality of regenerative treatment for radicular cysts.

Sinus Augmentation by Platelet-Rich Fibrin Alone: A Report of Two Cases with Histological Examinations

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Naofumi Aoki

2016-01-01

Full Text Available In sinus floor augmentation of an atrophic posterior maxilla, platelet-rich fibrin (PRF has been used as a graft material. We herein report two cases with histological evaluations of PRF after the surgery. The first case was a 28-year-old female with an atrophic right posterior maxilla who was treated with sinus floor augmentation and simultaneous implant placement using PRF as the sole graft material in our hospital. Twenty-four months after surgery, the implant was unfortunately removed because of occlusal overloading by parafunctional habits. During implant replacement, a tissue sample was obtained from the site of augmentation with PRF and was evaluated histologically. The second case was a 58-year-old man with severe alveolar atrophy of the right maxilla who underwent lateral sinus augmentation using only PRF in a two-stage procedure in our hospital. Samples were obtained at the second-stage surgery and histological examinations were performed. As a result, new bone formation was confirmed histologically in both cases. Our findings show that the use of PRF as a graft material during sinus floor augmentation induces natural bone regeneration.

Revealing −1 Programmed Ribosomal Frameshifting Mechanisms by Single-Molecule Techniques and Computational Methods

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Kai-Chun Chang

2012-01-01

Full Text Available Programmed ribosomal frameshifting (PRF serves as an intrinsic translational regulation mechanism employed by some viruses to control the ratio between structural and enzymatic proteins. Most viral mRNAs which use PRF adapt an H-type pseudoknot to stimulate −1 PRF. The relationship between the thermodynamic stability and the frameshifting efficiency of pseudoknots has not been fully understood. Recently, single-molecule force spectroscopy has revealed that the frequency of −1 PRF correlates with the unwinding forces required for disrupting pseudoknots, and that some of the unwinding work dissipates irreversibly due to the torsional restraint of pseudoknots. Complementary to single-molecule techniques, computational modeling provides insights into global motions of the ribosome, whose structural transitions during frameshifting have not yet been elucidated in atomic detail. Taken together, recent advances in biophysical tools may help to develop antiviral therapies that target the ubiquitous −1 PRF mechanism among viruses.

Effects of an injectable platelet-rich fibrin on osteoblast behavior and bone tissue formation in comparison to platelet-rich plasma.

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Wang, Xuzhu; Zhang, Yufeng; Choukroun, Joseph; Ghanaati, Shahram; Miron, Richard J

2018-01-01

Platelet-rich plasma (PRP) has been utilized for many years as a regenerative agent capable of inducing vascularization of various tissues using blood-derived growth factors. Despite this, drawbacks mostly related to the additional use of anti-coagulants found in PRP have been shown to inhibit the wound healing process. For these reasons, a novel platelet concentrate has recently been developed with no additives by utilizing lower centrifugation speeds. The purpose of this study was therefore to investigate osteoblast behavior of this novel therapy (injectable-platelet-rich fibrin; i-PRF, 100% natural with no additives) when compared to traditional PRP. Human primary osteoblasts were cultured with either i-PRF or PRP and compared to control tissue culture plastic. A live/dead assay, migration assay as well as a cell adhesion/proliferation assay were investigated. Furthermore, osteoblast differentiation was assessed by alkaline phosphatase (ALP), alizarin red and osteocalcin staining, as well as real-time PCR for genes encoding Runx2, ALP, collagen1 and osteocalcin. The results showed that all cells had high survival rates throughout the entire study period irrespective of culture-conditions. While PRP induced a significant 2-fold increase in osteoblast migration, i-PRF demonstrated a 3-fold increase in migration when compared to control tissue-culture plastic and PRP. While no differences were observed for cell attachment, i-PRF induced a significantly higher proliferation rate at three and five days when compared to PRP. Furthermore, i-PRF induced significantly greater ALP staining at 7 days and alizarin red staining at 14 days. A significant increase in mRNA levels of ALP, Runx2 and osteocalcin, as well as immunofluorescent staining of osteocalcin was also observed in the i-PRF group when compared to PRP. In conclusion, the results from the present study favored the use of the naturally-formulated i-PRF when compared to traditional PRP with anti

Comparison of matched sibling donors versus unrelated donors in allogeneic stem cell transplantation for primary refractory acute myeloid leukemia: a study on behalf of the Acute Leukemia Working Party of the EBMT

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Eolia Brissot

2017-06-01

Full Text Available Abstract Background Primary refractory acute myeloid leukemia (PRF-AML is associated with a dismal prognosis. Allogeneic stem cell transplantation (HSCT in active disease is an alternative therapeutic strategy. The increased availability of unrelated donors together with the significant reduction in transplant-related mortality in recent years have opened the possibility for transplantation to a larger number of patients with PRF-AML. Moreover, transplant from unrelated donors may be associated with stronger graft-mediated anti-leukemic effect in comparison to transplantations from HLA-matched sibling donor, which may be of importance in the setting of PRF-AML. Methods The current study aimed to address the issue of HSCT for PRF-AML and to compare the outcomes of HSCT from matched sibling donors (n = 660 versus unrelated donors (n = 381, for patients with PRF-AML between 2000 and 2013. The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate. Results HSCT provide patients with PRF-AML a 2-year leukemia-free survival and overall survival of about 25 and 30%, respectively. In multivariate analysis, two predictive factors, cytogenetics and time from diagnosis to transplant, were associated with lower leukemia-free survival, whereas Karnofsky performance status at transplant ≥90% was associated with better leukemia-free survival (LFS. Concerning relapse incidence, cytogenetics and time from diagnosis to transplant were associated with increased relapse. Reduced intensity conditioning regimen was the only factor associated with lower non-relapse mortality. Conclusions HSCT was able to rescue about one quarter of the patients with PRF-AML. The donor type did not have any impact on PRF patients’ outcomes. In contrast, time to transplant was a major prognostic factor for LFS. For patients with PRF-AML who do not have a matched sibling donor, HSCT from an

Quantitative assessment of pulmonary regurgitation in patients with and without right ventricular tract obstruction

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Spiewak, Mateusz, E-mail: mspiewak@ikard.pl [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Biernacka, Elzbieta K., E-mail: kbiernacka@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Malek, Lukasz A., E-mail: lmalek@ikard.pl [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Department of Interventional Cardiology and Angiology, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Misko, Jolanta, E-mail: jmisko@wp.pl [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Department of Radiology, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Kowalski, Miroslaw, E-mail: mkowalski@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Milosz, Barbara, E-mail: barbara-milosz@o2.pl [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Department of Radiology, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Zabicka, Magdalena, E-mail: mzabicka@onet.eu [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Dept. of Radiology, Inst. of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland); Ruzyllo, Witold, E-mail: wruzyllo@ikard.pl [Inst. of Cardiology, ul. Alpejska 42, 04-628 Warsaw (Poland)

2011-11-15

Background: There are concerns whether there is a difference in clinical utility of pulmonary regurgitation (PR) fraction (PRF) and PR volume (PRV) in subgroups of patients with isolated PR and individuals with combined PR and right ventricular outflow tract obstruction (RVOTO). The aim of the study was to compare PRF and PRV in patients with or without RVOTO. Methods and results: 82 consecutive patients after repair of tetralogy of Fallot (TOF) who underwent cardiovascular magnetic resonance and echocardiography were studied. There was no difference in PRF between patients with moderate and severe right ventricular (RV) dilatation (32 {+-} 13% vs. 37 {+-} 12%; p = 0.18). Significant difference in PRV was observed between these groups (23 {+-} 10 ml/m{sup 2} vs. 31 {+-} 12 ml/m{sup 2}, respectively; p = 0.02). PRV had better ability than PRF in identification of severe RV dilatation, both in group with RVOTO [area under the curve (AUC) 0.82 vs. 0.72, p = 0.005] and in patients without RVOTO (AUC 0.83 vs. 0.77, p = 0.04). A strong correlation was seen between PRF and PRV both in patients with and without RVOTO [r = 0.93, p < 0.0001 and r = 0.92, p < 0.0001, respectively]. In both subgroups high variability of PRF was found in subjects with similar degree of PRV. Conclusions: PRV shows better ability than PRF in evaluating influence of PR on RV in patients after TOF repair, both in population with and without concomitant RVOTO.

The effect of platelet rich fibrin on growth factor levels in urethral repair.

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Soyer, Tutku; Ayva, Şebnem; Boybeyi, Özlem; Aslan, Mustafa Kemal; Çakmak, Murat

2013-12-01

Platelet rich fibrin (PRF) is an autologous source of growth factors and promotes wound healing. An experimental study was performed to evaluate the effect of PRF on growth factor levels in urethral repair. Eighteen Wistar albino rats were included in the study. Rats were allocated in three groups (n:6): control (CG), sham (SG), and PRF (PRFG). In SG, a 5 mm vertical incision was performed in the penile urethra and repaired with 10/0 Vicryl® under a microscope. In PRFG, during the urethral repair as described in SG, 1 cc of blood was sampled from each rat and centrifuged for 10 minutes at 2400 rpm. PRF obtained from the centrifugation was placed on the repair site during closure. Penile urethras were sampled 24 hours after PRF application in PRFG and after urethral repair in SG. Transforming growth factor beta receptor (TGF-β-R-CD105), vascular endothelial growth factor (VEGF) and its receptor (VEGF-R), as well as endothelial growth factor receptor (EGFR), were evaluated in subepithelia of the penile skin and urethra. Groups were compared for growth factor levels and growth factor receptor expression with the Kruskal Wallis test. TGF-β-R levels were significantly decreased in SG when compared to CG (p0.05). Use of PRF after urethral repair increases TGF-β-R and VEGF expressions in urethral tissue. PRF can be considered as an alternative measure to improve the success of urethral repair. © 2013.

Achilles Tendon Open Surgical Treatment With Platelet-Rich Fibrin Matrix Augmentation: Biomechanical Evaluation.

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Alviti, Federica; Gurzì, Michele; Santilli, Valter; Paoloni, Marco; Padua, Roberto; Bernetti, Andrea; Bernardi, Marco; Mangone, Massimiliano

The relationship between surgical technique and ankle biomechanical properties after surgery for acute rupture of the Achilles tendon (ATR) has not yet been fully investigated. Platelet-rich fibrin (PRF) matrices seem to play a central role in the complex processes of tendon healing. Our aim was to analyze the biomechanical characteristics, stiffness, and mechanical work of the ankle during walking in patients who had undergone surgery after ATR with and without PRF augmentation. We performed a retrospective review of all consecutive patients who had been treated with surgical repair after ATR. Of the 20 male subjects enrolled, 9 (45%) had undergone conventional open repair of the Achilles tendon using the Krackow technique (no-PRF) and 11 (55%) had undergone surgery with PRF augmentation. An additional 8 healthy subjects were included as a control group. A gait analysis evaluation was performed at 6 months after surgery. The percentage of the stance time of the operated leg, double-support time of the healthy leg, and net work of the ankle during the gait cycle showed statistically significant differences between the no-PRF and the healthy group (p < .005). No differences were found between the PRF and healthy groups. Treatment with suture and PRF augmentation could result in significant functional improvements in term of efficiency of motion. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Comparing different stimulus configurations for population receptive field mapping in human fMRI

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Ivan eAlvarez

2015-02-01

Full Text Available Population receptive field (pRF mapping is a widely used approach to measuring aggregate human visual receptive field properties by recording non-invasive signals using functional MRI. Despite growing interest, no study to date has systematically investigated the effects of different stimulus configurations on pRF estimates from human visual cortex. Here we compared the effects of three different stimulus configurations on a model-based approach to pRF estimation: size-invariant bars and eccentricity-scaled bars defined in Cartesian coordinates and traveling along the cardinal axes, and a novel simultaneous ‘wedge and ring’ stimulus defined in polar coordinates, systematically covering polar and eccentricity axes. We found that the presence or absence of eccentricity scaling had a significant effect on goodness of fit and pRF size estimates. Further, variability in pRF size estimates was directly influenced by stimulus configuration, particularly for higher visual areas including V5/MT+. Finally, we compared eccentricity estimation between phase-encoded and model-based pRF approaches. We observed a tendency for more peripheral eccentricity estimates using phase-encoded methods, independent of stimulus size. We conclude that both eccentricity scaling and polar rather than Cartesian stimulus configuration are important considerations for optimal experimental design in pRF mapping. While all stimulus configurations produce adequate estimates, simultaneous wedge and ring stimulation produced higher fit reliability, with a significant advantage in reduced acquisition time.

Structure-Based Analysis of Toxoplasma gondii Profilin: A Parasite-Specific Motif Is Required for Recognition by Toll-Like Receptor 11

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K Kucera; A Koblansky; L Saunders; K Frederick; E De La Cruz; S Ghosh; Y Modis

2011-12-31

Profilins promote actin polymerization by exchanging ADP for ATP on monomeric actin and delivering ATP-actin to growing filament barbed ends. Apicomplexan protozoa such as Toxoplasma gondii invade host cells using an actin-dependent gliding motility. Toll-like receptor (TLR) 11 generates an innate immune response upon sensing T. gondii profilin (TgPRF). The crystal structure of TgPRF reveals a parasite-specific surface motif consisting of an acidic loop, followed by a long {beta}-hairpin. A series of structure-based profilin mutants show that TLR11 recognition of the acidic loop is responsible for most of the interleukin (IL)-12 secretion response to TgPRF in peritoneal macrophages. Deletion of both the acidic loop and the {beta}-hairpin completely abrogates IL-12 secretion. Insertion of the T. gondii acidic loop and {beta}-hairpin into yeast profilin is sufficient to generate TLR11-dependent signaling. Substitution of the acidic loop in TgPRF with the homologous loop from the apicomplexan parasite Cryptosporidium parvum does not affect TLR11-dependent IL-12 secretion, while substitution with the acidic loop from Plasmodium falciparum results in reduced but significant IL-12 secretion. We conclude that the parasite-specific motif in TgPRF is the key molecular pattern recognized by TLR11. Unlike other profilins, TgPRF slows nucleotide exchange on monomeric rabbit actin and binds rabbit actin weakly. The putative TgPRF actin-binding surface includes the {beta}-hairpin and diverges widely from the actin-binding surfaces of vertebrate profilins.

A Novel Technique for Conjunctivoplasty in a Rabbit Model: Platelet-Rich Fibrin Membrane Grafting

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Mehmet Erol Can

2016-01-01

Full Text Available Purpose. To investigate the effect of platelet-rich fibrin (PRF membrane on wound healing. Methods. Twenty-four right eyes of 24 New Zealand rabbits equally divided into 2 groups for the study design. After the creation of 5 × 5 mm conjunctival damage, it was secured with PRF membrane, which was generated from the rabbit’s whole blood samples in PRF membrane group, whereas damage was left unsutured in the control group. Three animals were sacrificed in each group on the 1st, 3rd, 7th, and 28th postoperative days. Immunohistochemical (IHC stainings and biomicroscopic evaluation were performed and compared between groups. Results. PRF membrane generated significant expressions of vascular endothelial growth factor (VEGF, transforming growth factor-beta (TGF-β, and platelet-derived growth factor (PDGF in the early postoperative period. However, the IHC evaluation allowed showing the excessive staining at day 28, in control group. Biomicroscopic evaluation revealed complete epithelialization in PRF membrane group, but none of the cases showed complete healing in the control group. Conclusions. This experimental study showed us the beneficial effects of the PRF membrane on conjunctival healing. Besides its chemical effects, it provides mechanical support as a scaffold for the migrating cells that are important for ocular surface regeneration. These overall results encourage us to apply autologous PRF membrane as a growth factor-enriched endogenous scaffold for ocular surface reconstruction.

Molecular study of the perforin gene in familial hematological malignancies

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El Abed Rim

2011-09-01

Full Text Available Abstract Perforin gene (PRF1 mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in the PRF1 coding region amounted to 3.7% (3/81. Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutated PRF1 in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein.

Novel use of platelet-rich fibrin matrix and MTA as an apical barrier in the management of a failed revascularization case.

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Yadav, Pankaj; Pruthi, Preeti Jain; Naval, Ruchika Roongta; Talwar, Sangeeta; Verma, Mahesh

2015-08-01

We report management of a failed revascularization/revitalization case, which could be due to inadequate removal of biofilm and bacteria in dentinal tubules. The use of an apical matrix barrier in form of a platelet-rich fibrin (PRF) membrane for stabilization of MTA in root end apexification procedure is described. The canal was cleansed of old MTA present in the cervical third using H files, irrigated using saline and finally irrigated with 2.5% NaOCl and saline. To obtain canal disinfection, calcium hydroxide paste was temporized in the canal. In subsequent appointments, PRF was placed at the root tip followed by 5-mm apical plug with mineral trioxide aggregate. One week later, the root canal was obturated with thermoplasticized gutta-percha. A 6-month and a 2-year follow ups showed reduction of periapical radiolucency and adequately functional tooth. One-visit apexification techniques provide an alternative treatment for failed revascularization cases. Follow up confirmed complete healing periradicularly. Apexification in one step using an apical barrier of PRF and a plug of MTA can be considered a predictable treatment and may be an alternative to long-term revascularization failures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Form or content: The application of user perspectives in treatment research

DEFF Research Database (Denmark)

Kolind, Torsten

2007-01-01

As part of a general trend in modern society, the voice of the 'consumers' of the services of the welfare state has gained increased legitimacy. However, this is not the case when it comes to drug-treatment users. The continuing neglect of this group's experiences is also reflected in methadone...... with users were made, and two months of participant observation were conducted in the clinics. An important finding is that the users highlighted the form of the treatment as much as the actual content. It was not primarily the content of the services, but how the services were carried out that mattered...... maintenance treatment research. This article seeks to counter this imbalance by exploring users' experiences with enhanced psychosocial methadone maintenance treatment. The findings rest on an evaluation of the Danish Methadone Project. As part of the evaluation 37 semi-structured qualitative interviews...

Experimental Evaluation of the Effectiveness of Demineralized Bone Matrix and Collagenated Heterologous Bone Grafts Used Alone or in Combination with Platelet-Rich Fibrin on Bone Healing in Sinus Floor Augmentation.

Science.gov (United States)

Peker, Elif; Karaca, Inci Rana; Yildirim, Benay

2016-01-01

The aim of this study was an experimental evaluation of the effectiveness of demineralized bone matrix (DBM) and collagenated heterologous bone graft (CHBG) used alone or in combination with platelet-rich fibrin on bone healing in sinus floor augmentation procedures. In this study, 36 New Zealand rabbits were used. The bilateral sinus elevation was performed, and 72 defects were obtained. The rabbit maxillary sinuses were divided into four groups according to the augmentation biomaterials obtained: demineralized bone matrix (Grafton DBM Putty, Osteotech; DBM group), DBM combined with platelet-rich fibrin (PRF; DBM + PRF group), collagenated heterologous bone graft (CHBG; Apatos Mix, OsteoBiol, Tecnoss; CHBG group), CHBG combined with PRF (CHBG + PRF group). All groups were sacrificed at 2, 4, and 8 weeks after surgery for histologic, histomorphometric, and immunohistochemical analyses. The inflammatory reaction was moderate to intense at the second week in all groups and declined from 2 to 8 weeks. New bone formation was started at the second week and increased from 2 to 8 weeks in all groups. There was no significant difference in bone formation between the experimental groups that used PRF mixed graft material and control groups that used only graft material. The percentage of new bone formation showed a significant difference in DBM groups and DBM + PRF groups compared with other groups. There were osteoclasts around all the bone graft materials used, but the percentage of residual graft particles was significantly higher in CHBG groups and CHBG + PRF groups at the eighth week. There is no beneficial effect of the application of PRF in combination with demineralized bone matrix or collagenated heterologous bone graft on bone formation in sinus floor augmentation. The results of this study showed that both collagenated heterologous bone graft and demineralized bone matrix have osteoconductive properties, but demineralized bone matrix showed more bone formation

Evaluation of the effects of platelet-rich fibrin on bone regeneration in diabetic rabbits.

Science.gov (United States)

Durmuşlar, M Cenk; Ballı, Umut; Öngöz Dede, Figen; Bozkurt Doğan, Şeyma; Mısır, A Ferhat; Barış, Emre; Yılmaz, Zehra; Çelik, H Hamdi; Vatansever, Alper

2016-02-01

This study aimed to investigate the effect of platelet-rich fibrin on bone regeneration in critical size defects in the calvaria of diabetic rabbits. In total, 40 male New Zealand rabbits, were divided into two groups a non-diabetic control group (Group A) and a diabetic experimental group (Group B). Two bicortical circular defects 15 mm in diameter were created in the parietal bone of each animal. Each group was further divided into four groups: subgroup E, the defect was left empty; subgroup PRF, the defects were filled only with PRF; subgroup AB, the defects were filled with autogenous bone; subgroup AB + PRF, the defects were filled with autogenous bone combined with PRF. The animals sacrificed at 4 weeks and 8 weeks. Bone formation was assessed by micro-computed tomography (micro-CT) scanning, histological and histomorphometric analysis. The total percent of new bone was the lowest in group A-E (6.77 ± 0.21 at 4 weeks, 11.01 ± 0.37 at 8 weeks) and highest in group A-AB + PRF (21.66 ± 0.91 at 4 weeks, 37.46 ± 1.25 at 8 weeks; p < 0.05). The mean percent of new bone was greatest in group B-AB + PRF at 4 and 8 weeks (16.87 ± 0.92, 29.59 ± 1.09, respectively) and lowest in group B-E (5.83 ± 0.09 at 4 weeks, 7.36 ± 1.02 at 8 weeks). This study, despite its limitations, showed that PRF can be used safely and that PRF induced bone healing in diabetic rabbits. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits

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Soghra Bahmanpour

2016-11-01

Full Text Available Background: The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP and platelet-rich fibrin (PRF containing stromal cell-derived factor-1 (SDF1 as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. Methods: We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1. After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05. Results: Macroscopic evaluations revealed that international cartilage repair society (ICRS scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05. Conclusion: Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits.

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.

Fibrin glue mixed with platelet-rich fibrin as a scaffold seeded with dental bud cells for tooth regeneration.

Science.gov (United States)

Yang, Kai-Chiang; Wang, Chun-Hao; Chang, Hao-Hueng; Chan, Wing P; Chi, Chau-Hwa; Kuo, Tzong-Fu

2012-11-01

Odontogenesis is a complex process with a series of epithelial-mesenchymal interactions and odontogenic molecular cascades. In tissue engineering of teeth from stem cells, platelet-rich fibrin (PRF), which is rich in growth factors and cytokines, may improve regeneration. Accordingly, PRF was added into fibrin glue to enrich the microenvironment with growth factors. Unerupted second molar tooth buds were harvested from miniature swine and cultured in vitro for 3 weeks to obtain dental bud cells (DBCs). Whole blood was collected for the preparation of PRF and fibrin glue before surgery. DBCs were suspended in fibrin glue and then enclosed with PRF, and the DBC-fibrin glue-PRF composite was autografted back into the original alveolar sockets. Radiographic and histological examinations were used to identify the regenerated tooth structure 36 weeks after implantation. Immunohistochemical staining was used to detect proteins specific to tooth regeneration. One pig developed a complete tooth with crown, root, pulp, enamel, dentin, odontoblast, cementum, blood vessels, and periodontal ligaments in indiscriminate shape. Another animal had an unerupted tooth that expressed cytokeratin 14, dentin matrix protein-1, vascular endothelial growth factor, and osteopontin. This study demonstrated, using autogenic cell transplantation in a porcine model, that DBCs seeded into fibrin glue-PRF could regenerate a complete tooth. Copyright © 2011 John Wiley & Sons, Ltd.

Comparative evaluation of platelet count and antimicrobial efficacy of injectable platelet-rich fibrin with other platelet concentrates: An in vitro study

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Prerna Ashok Karde

2017-01-01

Full Text Available Background: Platelet concentrates are used in various medical procedures to promote soft- and hard-tissue regeneration. In recent times, their antimicrobial efficacy is also explored. However, various platelet concentrates have evolved which differ in the centrifugation protocols. One such recently introduced platelet concentrate is injectable platelet-rich fibrin (i-PRF concentrate. Hence, the aim was to evaluate the antimicrobial property, and platelet count of i-PRF in comparison to other platelet concentrates, i.e., PRF, platelet-rich plasma (PRP, and control (whole blood. Materials and Methods: Blood samples were obtained from 10 chronic generalized marginal gingivitis patients. Platelet concentrates were prepared using standardized centrifugation protocol. Platelet count was evaluated by manual counting method using smear preparation of each sample. Subsequently, antimicrobial activity against oral bacteria was examined on blood agar using disc diffusion method to quantify the inhibitory effects. Results: Statistical significance was analyzed by one-way analysis of variance (ANOVA. P 0.05. i-PRF showed statistically significant difference (P < 0.001 in platelet count when compared to control. It was also significant when compared to PRP (P < 0.01, PRF (P < 0.001. Conclusion: i-PRF has maximum antimicrobial efficacy and higher platelet count in comparison to other platelet concentrates, thereby indicating to have a better regenerative potential then others.

Quantitative assessment of pulmonary regurgitation in patients with and without right ventricular tract obstruction

International Nuclear Information System (INIS)

Spiewak, Mateusz; Biernacka, Elzbieta K.; Malek, Lukasz A.; Misko, Jolanta; Kowalski, Miroslaw; Milosz, Barbara; Petryka, Joanna; Zabicka, Magdalena; Ruzyllo, Witold

2011-01-01

Background: There are concerns whether there is a difference in clinical utility of pulmonary regurgitation (PR) fraction (PRF) and PR volume (PRV) in subgroups of patients with isolated PR and individuals with combined PR and right ventricular outflow tract obstruction (RVOTO). The aim of the study was to compare PRF and PRV in patients with or without RVOTO. Methods and results: 82 consecutive patients after repair of tetralogy of Fallot (TOF) who underwent cardiovascular magnetic resonance and echocardiography were studied. There was no difference in PRF between patients with moderate and severe right ventricular (RV) dilatation (32 ± 13% vs. 37 ± 12%; p = 0.18). Significant difference in PRV was observed between these groups (23 ± 10 ml/m 2 vs. 31 ± 12 ml/m 2 , respectively; p = 0.02). PRV had better ability than PRF in identification of severe RV dilatation, both in group with RVOTO [area under the curve (AUC) 0.82 vs. 0.72, p = 0.005] and in patients without RVOTO (AUC 0.83 vs. 0.77, p = 0.04). A strong correlation was seen between PRF and PRV both in patients with and without RVOTO [r = 0.93, p < 0.0001 and r = 0.92, p < 0.0001, respectively]. In both subgroups high variability of PRF was found in subjects with similar degree of PRV. Conclusions: PRV shows better ability than PRF in evaluating influence of PR on RV in patients after TOF repair, both in population with and without concomitant RVOTO.

Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol

KAUST Repository

Singh, Eshan

2017-03-28

The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.

Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol

KAUST Repository

Singh, Eshan; Waqas, Muhammad; Johansson, Bengt; Sarathy, Mani

2017-01-01

The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.

Long-term cytokine and growth factor release from equine platelet-rich fibrin clots obtained with two different centrifugation protocols.

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Jiménez-Aristizabal, Román F; López, Catalina; Álvarez, María E; Giraldo, Carlos; Prades, Marta; Carmona, Jorge U

2017-09-01

To compare the temporal release (over three weeks) of tumor necrosis factor alpha (TNF-α), interleukin 4 (IL-4), IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta-1 (TGF-β 1 ) from two platelet-rich fibrin (PRF) preparations from equine blood obtained at either 240g/8min or 416g/10min. Whole blood from 10 horses was used to obtain PRF clots by two different centrifugation protocols. After 1h of rest, PRF clots were deposited in wells with culture medium, which was changed at 6h, 24h and then every 48h to 21days. Cytokines and GFs were measured by ELISA at 1h (serum supernatants from PRF clots) and all time points of culture medium change. A negative control (plasma) and a positive control (blood lysate) were also included. There were no relevant differences between the two protocols for the temporal release of proteins. However, a significant (p=0.01) effect of time was noted. All cytokines were detected after 6h of PRF clot culture until day 21. GF were detected at 1h until day 21. The concentrations for these proteins diminished gradually over time. A highly significant (p=0.01) correlation was noticed between all the proteins evaluated. Leukocytes enmeshed in PRF clots were able to produce cytokines, TGF-β 1 and PDGF-BB. These findings demonstrate a paramount role of leukocytes in wound healing induced or modified by PRF clots in mammals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advanced platelet-rich fibrin: a new concept for cell-based tissue engineering by means of inflammatory cells.

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Ghanaati, Shahram; Booms, Patrick; Orlowska, Anna; Kubesch, Alica; Lorenz, Jonas; Rutkowski, Jim; Landes, Constantin; Sader, Robert; Kirkpatrick, Cj; Choukroun, Joseph

2014-12-01

Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.

Platelet-rich fibrin prepared from stored whole-blood samples.

Science.gov (United States)

Isobe, Kazushige; Suzuki, Masashi; Watanabe, Taisuke; Kitamura, Yutaka; Suzuki, Taiji; Kawabata, Hideo; Nakamura, Masayuki; Okudera, Toshimitsu; Okudera, Hajime; Uematsu, Kohya; Nakata, Koh; Tanaka, Takaaki; Kawase, Tomoyuki

2017-12-01

In regenerative therapy, self-clotted platelet concentrates, such as platelet-rich fibrin (PRF), are generally prepared on-site and are immediately used for treatment. If blood samples or prepared clots can be preserved for several days, their clinical applicability will expand. Here, we prepared PRF from stored whole-blood samples and examined their characteristics. Blood samples were collected from non-smoking, healthy male donors (aged 27-67 years, N = 6), and PRF clots were prepared immediately or after storage for 1-2 days. Fibrin fiber was examined by scanning electron microscopy. Bioactivity was evaluated by means of a bioassay system involving human periosteal cells, whereas PDGF-BB concentrations were determined by an enzyme-linked immunosorbent assay. Addition of optimal amounts of a 10% CaCl 2 solution restored the coagulative ability of whole-blood samples that contained an anticoagulant (acid citrate dextrose) and were stored for up to 2 days at ambient temperature. In PRF clots prepared from the stored whole-blood samples, the thickness and cross-links of fibrin fibers were almost identical to those of freshly prepared PRF clots. PDGF-BB concentrations in the PRF extract were significantly lower in stored whole-blood samples than in fresh samples; however, both extracts had similar stimulatory effects on periosteal-cell proliferation. Quality of PRF clots prepared from stored whole-blood samples is not reduced significantly and can be ensured for use in regenerative therapy. Therefore, the proposed method enables a more flexible treatment schedule and choice of a more suitable platelet concentrate immediately before treatment, not after blood collection.

Platelet-Poor Plasma as a Supplement for Fibroblasts Cultured in Platelet-Rich Fibrin

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Luiz Alexandre Chisini

2017-01-01

Full Text Available The aim of this study was to evaluate the proliferation and adhesion of mesenchymal cells (3T3/NIH in Dulbecco’s Modified Eagle Medium (DMEM supplemented with Platelet-Poor Plasma (PPP in a Platelet-Rich Fibrin (PRF scaffold. Human blood was obtained and processed in a centrifuge considering the equation G=1.12xRx (RPM/1000² to obtain PRF and PPP. Cell adhesion and maintenance analyses were performed by MTT assays in a 96 well plate with supplemented DMEM: PPP (90:10 for 24 hours. Besides, the PRF was deposited in a 48 well plate and 10x104 cells were seeded above each PRF (n=3 with 800μl of DMEM: PPP (90:10 and cultured for 7 days. Histological analysis and the immunohistochemical staining for Vimentin were performed. Results were analyzed by one-way ANOVA in Stata12®. A significant decrease (p0.05. Fibroblasts culture for 7 days in PRF supplemented with PPP 10% was possible, showing positive staining for Vimentin. Therefore, PPP cell supplementation decreased the initial adhesion of cells but was able to maintain the proliferation of adhered cells and able to support their viability in PRF. It seems that this method has many clinical advantages since it provides an autologous and natural scaffold with their respective supplement for cell culture by only one process, without using xenogeneic compounds. This could improve the potential of clinical translational therapies based on the use of PRF cultured cells, promoting the regenerative potential for future use in medicine and dentistry.

The combination use of platelet-rich fibrin and treated dentin matrix for tooth root regeneration by cell homing.

Science.gov (United States)

Ji, Baohui; Sheng, Lei; Chen, Gang; Guo, Shujuan; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

2015-01-01

Endogenous regeneration through cell homing provides an alternative approach for tissue regeneration, except cell transplantation, especially considering clinical translation. However, tooth root regeneration through cell homing remains a provocative approach in need of intensive study. Both platelet-rich fibrin (PRF) and treated dentin matrix (TDM) are warehouses of various growth factors, which can promote cell homing. We hypothesized that endogenous stem cells are able to sense biological cues from PRF membrane and TDM, and contribute to the regeneration of tooth root, including soft and hard periodontal tissues. Therefore, the biological effects of canine PRF and TDM on periodontal ligament stem cells (PDLSCs) and bone marrow mesenchymal stem cells (BMSCs) were evaluated respectively in vitro. Beagle dogs were used as orthotopic transplantation model. It was found that PRF significantly recruited and stimulated the proliferation of PDLSCs and BMSCs in vitro. Together, PRF and TDM induced cell differentiation by upregulating the mineralization-related gene expression of bone sialoprotein (BSP) and osteopotin (OPN) after 7 days coculture. In vivo, transplantation of autologous PRF and allogeneic TDM into fresh tooth extraction socket achieved successful root regeneration 3 months postsurgery, characterized by the regeneration of cementum and periodontal ligament (PDL)-like tissues with orientated fibers, indicative of functional restoration. The results suggest that tooth root connected to the alveolar bone by cementum-PDL complex can be regenerated through the implantation of PRF and TDM in a tooth socket microenvironment, probably by homing of BMSCs and PDLSCs. Furthermore, bioactive cues and inductive microenvironment are key factors for endogenous regeneration. This approach provides a tangible pathway toward clinical translation.

Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

KAUST Repository

Bhavani Shankar, Vijai Shankar; Sajid, Muhammad Bilal; Al-Qurashi, Khalid; Atef, Nour; Al Khesho, Issam; Ahmed, Ahfaz; Chung, Suk-Ho; Roberts, William L.; Morganti, Kai; Sarathy, Mani

2016-01-01

This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

An approach to research on embodiment and forms of knowledge : methodological challenges for interpretation

DEFF Research Database (Denmark)

Knudsen, Lars Emmerik Damgaard

argues. Studying a teacher training program, specifically the relation between placement and teaching, this presentation argues for a ‘meeting point’ and theoretical frame of Merleau-Ponty, Aristotle and Højrup that all dialectally grasps the relations between researcher and interviewee by understanding......Abstract: This paper is on the researcher’s role and the status of the data s/he is inclined to use. The outset is theories on embodied knowledge and knowledge forms such as Pierre Bourdieu, Hubert & Stuart Dreyfus and Jean Lave who all have troubles of how to view embodiment from either...... them as either bodily interwoven, life-mode or virtuously related. The inclusion of subjective perspectives and cultural conditions enlightens educational research as a process of interpretation where the embodied and life mode structured observation both opens and closes ways of interpretation...

System for manufacturing ash products and energy from refuse waste

Energy Technology Data Exchange (ETDEWEB)

Sutin, G.L.; Mahoney, P.F.

1996-01-04

The present invention provides a system of manufacturing energy and ash products from solid waste. The system includes apparatus for receiving solid waste for processing, apparatus for shredding the received solid waste, apparatus for removing ferrous material from the shredded solid waste to create processed refuse fuel (PRF) and apparatus for efficiently combusting the PRF. A conveyor transfers the PRF to the combusting apparatus such that the density of the PRF is always controlled for continuous non-problematic flow. Apparatus for recovering residual combustion particulate from the combustion residual gases and for recovering solid ash residue provides the system with the ability to generate steam and electrical energy, and to recover for reuse and recycling valuable materials from the solid ash residue. (author) figs.

Treatment of infrabony defects with platelet-rich fibrin along with bone graft: Case report

Directory of Open Access Journals (Sweden)

Surekha Y Bhedasgaonkar

2015-01-01

Full Text Available Although periodontitis is an infectious disease of periodontal tissues, changes that occur in the bone are crucial, because destruction of bone is responsible for tooth loss. Although horizontal bone loss is most common, vertical bone loss is more amenable to regenerative periodontal therapy. Recently, importance has been given to use of platelet-rich fibrin (PRF for predictably obtaining periodontal regeneration. PRF is a concentrated suspension of growth factors found in platelets. These growth factors moderate the wound healing and promote tissue regeneration. This article includes case reports of two patients who showed infrabony defects that were treated with combining PRF with allograft. This case report tried to compare the clinical and radiographical outcome obtained by combination of PRF and allograft.

Comparison of efficacy of continuous epidural block and pulsed radiofrequency to the dorsal root ganglion for management of pain persisting beyond the acute phase of herpes zoster.

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Eung Don Kim

Full Text Available There is little evidence regarding the effectiveness of intervention methods in the treatment of zoster-related pain (ZAP after the acute phase of zoster. Generally, if ZAP remains after more than 180 days from its onset, the likelihood of pain reduction is very low; this condition is considered as a "well established" post-herpetic neuralgia (PHN. Although the clinical efficacy of intrathecal steroid injection and spinal cord stimulation (SCS for ZAP management has been reported, these interventions are not widely used due to inherent disadvantages. Continuous epidural block is widely used in clinical practice, and the effectiveness of pulsed radiofrequency (PRF to the dorsal root ganglion (DRG in the treatment of ZAP already has been reported.The purpose of this study was to compare the clinical efficacy of continuous epidural block and DRG PRF beyond acute phase of zoster, bur before PHN was well established (from 30 days to180 days after zoster onset.Retrospective comparative study.A total of 42 medical records were analyzed. Patients were divided into two groups according to the type of procedure utilized: continuous epidural block (continuous epidural group and DRG PRF (PRF group. The clinical efficacy of the procedure was evaluated using a numeric rating scale (NRS and the medication dose before and 1 to 6 months after the procedure.There was a significant decrease in the NRS value with time in both groups. However, this decrease was more significant in the PRF group than in the continuous epidural group. The medication doses decreased significantly in the PRF group over time, but not in the continuous epidural group. The rate of clinically meaningful PHN (NRS≥3 was also lower in the PRF group than in the continuous epidural group.This study revealed that DRG PRF was more effective than a continuous epidural block in treating ZAP after the acute phase of zoster. A neuromodulation method such as DRG PRF may be a useful option for

Demonstration and Validation of a High-Performance Floor-Sealant System to Reduce Concrete Degradation

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2015-05-01

1 Recycled Antifreeze 01-197-7692 MIL-PRF-10924H GAA Grease 01-102-9455 MIL-PRF-46176B Brake Fluid 00-252-6383 MIL-PRF-5606H Hydraulic Fluid H515...contaminated clothing , clean thoroughly before reuse. Inhalation: Move to fresh air. If not breathing, give rescue breathing. I f breathing is...material to absorb the spill, use plastic shovel to pick up absorbent for disposal Spills and Leaks: Dispose in accordance to local, state or federal

Role of plasma-rich fibrin in oral surgery

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Kumar, K. Retna; Genmorgan, K.; Abdul Rahman, S. M.; Rajan, M. Alaguvel; Kumar, T. Arul; Prasad, V. Srinivas

2016-01-01

Platelet-rich fibrin (PRF) is a fibrin meshwork, in which platelet cytokines, growth factors, and cells are entrapped and discharged after a period and can serve as a resorbable film. PRF is the next generation of platelet concentrates equipped to improve arrangement without biochemical blood handling; PRF is an evolution of the fibrin adhesive, which is widely used in the oral surgery. The guidelines of this innovation depend on concentrating platelets and growth factors in a plasma medium, ...

An analysis of the readability of patient information and consent forms used in research studies in anaesthesia in Australia and New Zealand.

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Taylor, H E; Bramley, D E P

2012-11-01

The provision of written information is a component of the informed consent process for research participants. We conducted a readability analysis to test the hypothesis that the language used in patient information and consent forms in anaesthesia research in Australia and New Zealand does not meet the readability standards or expectations of the Good Clinical Practice Guidelines, the National Health and Medical Research Council in Australia and the Health Research Council of New Zealand. We calculated readability scores for 40 patient information and consent forms using the Simple Measure of Gobbledygook and Flesch-Kincaid formulas. The mean grade level of patient information and consent forms when using the Simple Measure of Gobbledygook and Flesch-Kincaid readability formulas was 12.9 (standard deviation of 0.8, 95% confidence interval 12.6 to 13.1) and 11.9 (standard deviation 1.1, 95% confidence interval 11.6 to 12.3), respectively. This exceeds the average literacy and comprehension of the general population in Australia and New Zealand. Complex language decreases readability and negatively impacts on the informed consent process. Care should be exercised when providing written information to research participants to ensure language and readability is appropriate for the audience.

Platelet rich fibrin in jaw defects

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Nica, Diana; Ianes, Emilia; Pricop, Marius

2016-03-01

Platelet rich fibrin (PRF) is a tissue product of autologous origin abundant in growth factors, widely used in regenerative procedures. Aim of the study: Evaluation of the regenerative effect of PRF added in the bony defects (after tooth removal or after cystectomy) Material and methods: The comparative nonrandomized study included 22 patients divided into 2 groups. The first group (the test group) included 10 patients where the bony defects were treated without any harvesting material. The second group included 12 patients where the bony defects were filled with PRF. The bony defect design was not critical, with one to two walls missing. After the surgeries, a close clinically monitoring was carried out. The selected cases were investigated using both cone beam computer tomography (CBCT) and radiographic techniques after 10 weeks postoperatively. Results: Faster bone regeneration was observed in the bony defects filled with PRF comparing with the not grafted bony defects. Conclusions: PRF added in the bony defects accelerates the bone regeneration. This simplifies the surgical procedures and decreases the economic costs.

Attraction of position preference by spatial attention throughout human visual cortex.

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Klein, Barrie P; Harvey, Ben M; Dumoulin, Serge O

2014-10-01

Voluntary spatial attention concentrates neural resources at the attended location. Here, we examined the effects of spatial attention on spatial position selectivity in humans. We measured population receptive fields (pRFs) using high-field functional MRI (fMRI) (7T) while subjects performed an attention-demanding task at different locations. We show that spatial attention attracts pRF preferred positions across the entire visual field, not just at the attended location. This global change in pRF preferred positions systematically increases up the visual hierarchy. We model these pRF preferred position changes as an interaction between two components: an attention field and a pRF without the influence of attention. This computational model suggests that increasing effects of attention up the hierarchy result primarily from differences in pRF size and that the attention field is similar across the visual hierarchy. A similar attention field suggests that spatial attention transforms different neural response selectivities throughout the visual hierarchy in a similar manner. Copyright © 2014 Elsevier Inc. All rights reserved.

Climate Comics: polar research in a cartoon form

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Courville, Z.; Carbaugh, S.; Defrancis, G.; Donegan, R.; Brown, C.; Perovich, D. K.; Richter-Menge, J.

2013-12-01

Climate Comics is a collaborative outreach effort between the Montshire Museum of Science, in Norwich, VT, the Cold Regions Research and Engineering Laboratory (CRREL) research staff, and freelance artist and recent graduate of the Center for Cartoon Studies in White River Junction, VT, Sam Carbaugh. The project involves the cartoonist, the education staff from the museum, and researchers from CRREL creating a series of comic books with polar science and research themes, including sea ice monitoring, sea ice albedo, ice cores, extreme microbial activity, and stories and the process of fieldwork. The aim of the comic series is to provide meaningful science information in a comic-format that is both informative and fun, while highlighting current polar research work done at the lab. The education staff at the Montshire Museum develops and provides a series of hands-on, inquiry-based activity descriptions to complement each comic book, and CRREL researchers provide science background information and reiterative feedback about the comic books as they are being developed. Here, we present the motivation for using the comic-book medium to present polar research topics, the process involved in creating the comics, some unique features of the series, and the finished comic books themselves. Cartoon illustrating ways snow pack can be used to determine past climate information.

Male pheromone protein components activate female vomeronasal neurons in the salamander Plethodon shermani

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Feldhoff Pamela W

2006-03-01

Full Text Available Abstract Background The mental gland pheromone of male Plethodon salamanders contains two main protein components: a 22 kDa protein named Plethodon Receptivity Factor (PRF and a 7 kDa protein named Plethodon Modulating Factor (PMF, respectively. Each protein component individually has opposing effects on female courtship behavior, with PRF shortening and PMF lengthening courtship. In this study, we test the hypothesis that PRF or PMF individually activate vomeronasal neurons. The agmatine-uptake technique was used to visualize chemosensory neurons that were activated by each protein component individually. Results Vomeronasal neurons exposed to agmatine in saline did not demonstrate significant labeling. However, a population of vomeronasal neurons was labeled following exposure to either PRF or PMF. When expressed as a percent of control level labeled cells, PRF labeled more neurons than did PMF. These percentages for PRF and PMF, added together, parallel the percentage of labeled vomeronasal neurons when females are exposed to the whole pheromone. Conclusion This study suggests that two specific populations of female vomeronasal neurons are responsible for responding to each of the two components of the male pheromone mixture. These two neural populations, therefore, could express different receptors which, in turn, transmit different information to the brain, thus accounting for the different female behavior elicited by each pheromone component.

Identification of a Peptide-Pheromone that Enhances Listeria monocytogenes Escape from Host Cell Vacuoles

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Xayarath, Bobbi; Alonzo, Francis; Freitag, Nancy E.

2015-01-01

Listeria monocytogenes is a Gram-positive facultative intracellular bacterial pathogen that invades mammalian cells and escapes from membrane-bound vacuoles to replicate within the host cell cytosol. Gene products required for intracellular bacterial growth and bacterial spread to adjacent cells are regulated by a transcriptional activator known as PrfA. PrfA becomes activated following L. monocytogenes entry into host cells, however the signal that stimulates PrfA activation has not yet been defined. Here we provide evidence for L. monocytogenes secretion of a small peptide pheromone, pPplA, which enhances the escape of L. monocytogenes from host cell vacuoles and may facilitate PrfA activation. The pPplA pheromone is generated via the proteolytic processing of the PplA lipoprotein secretion signal peptide. While the PplA lipoprotein is dispensable for pathogenesis, bacteria lacking the pPplA pheromone are significantly attenuated for virulence in mice and have a reduced efficiency of bacterial escape from the vacuoles of nonprofessional phagocytic cells. Mutational activation of PrfA restores virulence and eliminates the need for pPplA-dependent signaling. Experimental evidence suggests that the pPplA peptide may help signal to L. monocytogenes its presence within the confines of the host cell vacuole, stimulating the expression of gene products that contribute to vacuole escape and facilitating PrfA activation to promote bacterial growth within the cytosol. PMID:25822753

Comparative effects in rats of intact wheat bran and two wheat bran fractions on the disposition of the mutagen 2-amino-3-methylimidazo[4,5-f]quinoline

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Ferguson, Lynnette R.; Harris, Philip J.; Kestell, Philip; Zhu, Shuotun; Munday, Rex; Munday, Christine M.

2011-01-01

Wheat bran protects against mutations and cancer, but contains different plant cell types that are likely to have different protective effects. We previously described the production and chemical characterisation of an aleurone-rich fraction (ARF) and a pericarp-rich fraction (PRF) from wheat grain. We compared these with whole bran (WB), fed to rats as 10% of a high fat AIN-76 diet. All bran-supplemented diets increased faecal bulk, in the order PRF > WB > ARF. PRF increased the activity of NAD(P)H:quinone acceptor oxidoreductase only in the forestomach, whereas ARF and WB enhanced levels of glutathione S-transferase in the duodenum. ARF but not PRF was digested and fermented, and also encouraged bacterial growth. Rats were gavaged with the radioactive mutagen 14 C-labelled IQ (2-amino-3-methylimidazo[4,5-f]quinoline), and effects of the brans on plasma radioactivity measured. Compared with the control diet, all bran-supplemented diets reduced the concentration of radioactivity in plasma, in the order ARF > PRF > WB. All brans increased faecal elimination of radioactivity, but only ARF and PRF enhanced urinary radioactivity. These data suggest that wheat bran may reduce mutation and cancers through direct adsorption and enhanced elimination of a dietary mutagen and/or its metabolites, and that wheat bran enriched in pericarp or aleurone cell walls may exert protective effects through different mechanisms.

Dialysis delivery of an adenosine A2A agonist into the pontine reticular formation of C57BL/6J mouse increases pontine acetylcholine release and sleep.

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Coleman, Christal G; Baghdoyan, Helen A; Lydic, Ralph

2006-03-01

In vivo microdialysis in C57BL/6J (B6) mouse was used to test the hypothesis that activating adenosine A(2A) receptors in the pontine reticular formation (PRF) increases acetylcholine (ACh) release and rapid eye movement (REM) sleep. Eight concentrations of the adenosine A(2A) receptor agonist 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS 21680; CGS) were delivered to the PRF and ACh in the PRF was quantified. ACh release was significantly increased by dialysis with 3 mum CGS and significantly decreased by dialysis with 10 and 100 microm CGS. Co-administration of the adenosine A(2A) receptor antagonist 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385; 30 nM) blocked the CGS-induced increase in ACh release. In a second series of experiments, CGS (3 microm) was delivered by dialysis to the PRF for 2 h while recording sleep and wakefulness. CGS significantly decreased time in wakefulness (-51% in h 1; -54% in h 2), increased time in non-rapid eye movement (NREM) sleep (90% in h 1; 151% in h 2), and increased both time in REM sleep (331% in h 2) and the number of REM sleep episodes (488% in h 2). The enhancement of REM sleep is consistent with the interpretation that adenosine A(2A) receptors in the PRF of the B6 mouse contribute to REM sleep regulation, in part, by increasing ACh release in the PRF. A(2A) receptor activation may promote NREM sleep via GABAergic inhibition of arousal promoting neurons in the PRF.

Vascularization after treatment of gingival recession defects with platelet-rich fibrin or connective tissue graft.

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Eren, Gülnihal; Kantarcı, Alpdoğan; Sculean, Anton; Atilla, Gül

2016-11-01

The aim of this study was to evaluate histologically the following treatment of bilateral localized gingival recessions with coronally advanced flap (CAF) combined with platelet-rich fibrin (PRF) or subepithelial connective tissue graft (SCTG). Tissue samples were harvested from 14 subjects either 1 or 6 months after the surgeries. The 2-mm punch biopsies were obtained from the mid-portion of the grafted sites. Neutral buffered formalin fixed, paraffin-embedded 5-μm thick tissue sections were stained with hematoxylin eosin and Masson's trichrome in order to analyze the collagen framework, epithelium thickness and rete-peg length. Multiple sequential sections were cut from paraffin-embedded blocks of tissue and immunohistochemically prepared for detection of vascular endothelial growth factor, CD31 and CD34, for the assessment of vascularization. Rete peg formation was significantly increased in the sites treated with PRF compared to the SCTG group after 6 months (p < 0.05). On the contrary, the number of vessels was increased in the SCTG group compared to the PRF group after 6 months (p < 0.05). No statistically significant differences were observed in the collagen density. Staining intensity of CD31 increased in submucosal area of PRF group than SCTG group after 1 month. Higher staining intensity of CD34 was observed in the submucosal area of PRF group compared with SCTG group after 6 months. The results of the present study suggest that in histological evaluation because of its biological compounds, PRF results earlier vessel formation and tissue maturation compared to connective tissue graft. PRF regulated the vascular response associated with an earlier wound healing.

Visual motion transforms visual space representations similarly throughout the human visual hierarchy.

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Harvey, Ben M; Dumoulin, Serge O

2016-02-15

Several studies demonstrate that visual stimulus motion affects neural receptive fields and fMRI response amplitudes. Here we unite results of these two approaches and extend them by examining the effects of visual motion on neural position preferences throughout the hierarchy of human visual field maps. We measured population receptive field (pRF) properties using high-field fMRI (7T), characterizing position preferences simultaneously over large regions of the visual cortex. We measured pRFs properties using sine wave gratings in stationary apertures, moving at various speeds in either the direction of pRF measurement or the orthogonal direction. We find direction- and speed-dependent changes in pRF preferred position and size in all visual field maps examined, including V1, V3A, and the MT+ map TO1. These effects on pRF properties increase up the hierarchy of visual field maps. However, both within and between visual field maps the extent of pRF changes was approximately proportional to pRF size. This suggests that visual motion transforms the representation of visual space similarly throughout the visual hierarchy. Visual motion can also produce an illusory displacement of perceived stimulus position. We demonstrate perceptual displacements using the same stimulus configuration. In contrast to effects on pRF properties, perceptual displacements show only weak effects of motion speed, with far larger speed-independent effects. We describe a model where low-level mechanisms could underlie the observed effects on neural position preferences. We conclude that visual motion induces similar transformations of visuo-spatial representations throughout the visual hierarchy, which may arise through low-level mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

The Treatment of Joint Pain with Intra-articular Pulsed Radiofrequency.

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Schianchi, Pietro M; Sluijter, Menno E; Balogh, Susan E

2013-09-01

The intra-articular (IA) application of pulsed radiofrequency (PRF) for pain in small and large joints represents a recent development that has proven to be effective in many cases. We performed a retrospective study of 89 such procedures in 57 consecutive patients with chronic articular pain. The aim of this retrospective study is to evaluate the effectiveness of intraarticular PRF in a group of 57 consecutive patients with chronic joint pain. Patients with intractable joint pain for more than 6 months were treated with IA PRF 40-45V for 10-15 min in small joints and 60V for 15 min in large joints using fluoroscopic confirmation of correct needle position. A total of 28 shoulders, 40 knees, 10 trapezio-metacarpal, and 11 first metatarso-phalangeal joints were treated. Results were evaluated at 1, 2, and 5 months. The procedure was repeated after 1 month in 10 patients with initial suboptimal results. Success was defined as a reduction of pain score by at least 50%. All groups showed significant reductions in pain scores at all three follow-up visits. Success rates were higher in small joints (90% and 82%, respectively) than large ones (64% and 60%, respectively). Interestingly, IA PRF was successful in 6 out of 10 patients who had undergone previous surgery, including 3 with prosthetic joint replacement and in 6 of the 10 repeated procedures. There were no significant adverse effects or complications. IA PRF induced significant pain relief of long duration in a majority of our patients with joint pain. The exact mechanism is unclear, but may be related to the exposure of immune cells to low-strength RF fields, inducing an anti-inflammatory effect. The success rate appears to be highest in small joints. We recommend additional research including control groups to further investigate and clarify this method; our data suggest that it may represent a useful modality in the treatment of arthrogenic pain.

Differential forms theory and practice

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Weintraub, Steven H

2014-01-01

Differential forms are utilized as a mathematical technique to help students, researchers, and engineers analyze and interpret problems where abstract spaces and structures are concerned, and when questions of shape, size, and relative positions are involved. Differential Forms has gained high recognition in the mathematical and scientific community as a powerful computational tool in solving research problems and simplifying very abstract problems through mathematical analysis on a computer. Differential Forms, 2nd Edition, is a solid resource for students and professionals needing a solid g

Interorganisational networking as the principal form of technological, innovative and research cooperation between Russia and the European Union in the Baltic region

Directory of Open Access Journals (Sweden)

Bolychev Oleg

2013-12-01

Full Text Available This article concerns the role that international cooperation in research, technology, and innovation plays in ensuring innovative development and producing an innovative model of the Russian economy. One of the key objectives of the country’s integration into international research, technological, and innovative space is the development of Russia-EU cooperation in the Baltic region. It is established that, with the development of integration connections and regionalization processes, interorganizational networking takes on special importance in the organization and development of the innovative space. The authors analyze the existing typologies of forms of cooperation in the field of research, technology, and innovation, within which cases of networking are identified. The article gives a definition of interorganizational networks in view of the spatial and structural components of networking. The authors introduce the notion of international interorganizational networks as a special form of international cooperation. A study into the spatial form of interorganizational networks helps explain the effect of different levels and types of economic integration. Key areas of research on international interorganizational networks are identified in view of the features of integration processes in the development of network processes and in the framework of network approach in general.

Interorganisational networking as the principal form of technological, innovative and research cooperation between Russia and the European Union in the Baltic region

Directory of Open Access Journals (Sweden)

Bolychev Oleg

2013-11-01

Full Text Available This article concerns the role that international cooperation in research, technology, and innovation plays in ensuring innovative development and producing an innovative model of the Russian economy. One of the key objectives of the country’s integration into international research, technological, and innovative space is the development of Russia-EU cooperation in the Baltic region. It is established that, with the development of integration connections and regionalization processes, interorganizational networking takes on special importance in the organization and development of the innovative space. The authors analyze the existing typologies of forms of cooperation in the field of research, technology, and innovation, within which cases of networking are identified. The article gives a definition of interorganizational networks in view of the spatial and structural components of networking. The authors introduce the notion of international interorganizational networks as a special form of international cooperation. A study into the spatial form of interorganizational networks helps explain the effect of different levels and types of economic integration. Key areas of research on international interorganizational networks are identified in view of the features of integration processes in the development of network processes and in the framework of network approach in general.

Effects of Pulsed Versus Conventional Versus Combined Radiofrequency for the Treatment of Trigeminal Neuralgia: A Prospective Study.

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Elawamy, Abdelraheem; Abdalla, Esam Eldein Mohamed; Shehata, Ghaydaa A

2017-09-01

During radiofrequency bursts of energy are applied to nervous tissue. The clinical advantages of this treatment remain unclear. We compared the effectiveness and pain relief for idiopathic trigeminal neuralgia (TN) after continuous radiofrequency (CRF), pulsed radiofrequency (PRF), and combined continuous and pulsed radiofrequency (CCPRF) treatment of the Gasserian ganglion (GG). We conducted a randomized prospective study. Forty-three patients were included. Eleven patients were treated with PRF at 42°C for 10 minutes (PRF group), 12 patients received CRF for 270 seconds at 75 °C (CRF group), and 20 patients received PRF for 10 minutes at 42°C followed by CRF for at 60°C for 270 seconds (CCPRF group). Assuit University Hospital, Pain and Neurology outpatient clinics. Patients were assessed for pain, satisfaction, and consumption of analgesics at baseline and 7 days, one month, 6 months, 12 months, and 24 months after the procedure. The incidence of complications, anesthesia dolorosa, weakness of muscles of mastication, numbness, and technical complications, was evaluated after the procedure. Excellent pain relief was achieved after 6, 12, and 24 months, respectively in 95%, 85%, and 70% of patients with CCPRF; 75%, 75%, and reduced to 50% among patients with CRF; and 82%, reduced to 9.1%, and 0% of patients with PRF. No complications were recorded in 75% of patients in the CCPRF and PRF groups. There was one case of anesthesia dolorosa, 4 cases of masseter muscle weakness, and 5 cases of severe numbness recorded in the CRF group. There was a small number of patients in each group. The best results were observed in the CCPRF group, followed by the CRF group, and then the PRF group.Key words: Pulsed, continuous, radiofrequency, trigeminal neuralgia, Gasserian ganglion.

Profilin-Dependent Nucleation and Assembly of Actin Filaments Controls Cell Elongation in Arabidopsis1[OPEN

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Cao, Lingyan; Blanchoin, Laurent; Staiger, Christopher J.

2016-01-01

Actin filaments in plant cells are incredibly dynamic; they undergo incessant remodeling and assembly or disassembly within seconds. These dynamic events are choreographed by a plethora of actin-binding proteins, but the exact mechanisms are poorly understood. Here, we dissect the contribution of Arabidopsis (Arabidopsis thaliana) PROFILIN1 (PRF1), a conserved actin monomer-binding protein, to actin organization and single filament dynamics during axial cell expansion of living epidermal cells. We found that reduced PRF1 levels enhanced cell and organ growth. Surprisingly, we observed that the overall frequency of nucleation events in prf1 mutants was dramatically decreased and that a subpopulation of actin filaments that assemble at high rates was reduced. To test whether profilin cooperates with plant formin proteins to execute actin nucleation and rapid filament elongation in cells, we used a pharmacological approach. Here, we used Small Molecule Inhibitor of Formin FH2 (SMIFH2), after validating its mode of action on a plant formin in vitro, and observed a reduced nucleation frequency of actin filaments in live cells. Treatment of wild-type epidermal cells with SMIFH2 mimicked the phenotype of prf1 mutants, and the nucleation frequency in prf1-2 mutant was completely insensitive to these treatments. Our data provide compelling evidence that PRF1 coordinates the stochastic dynamic properties of actin filaments by modulating formin-mediated actin nucleation and assembly during plant cell expansion. PMID:26574597

Platelet Rich Fibrin in double lateral sliding bridge flap procedure for gingival recession coverage: An original study

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Vijayalakshmi Rajaram

2015-01-01

Full Text Available Background: Gingival recession is a common occurrence in periodontal disease leading to an unaesthetic appearance of the gingiva. The effect of platelet-rich fibrin (PRF, when used along with double lateral sliding bridge flap (DLSBF, remains unknown. The aim of this study is to evaluate the effect of PRF in conjunction with DLSBF for multiple gingival recessions. Materials and Methods: Twenty systemically healthy individuals exhibiting Grade II gingival recession on their mandibular central incisors were recruited in this study. These patients were randomly assigned into two groups: DLSBF and PRF + DLSBF. The clinical parameters that were evaluated in this study were gingiva recession height, gingiva recession width, width of keratinized gingiva, clinical attachment level, and probing depth. PRF was procured from the patient's blood at the time of the surgery and used for the procedure. The follow-up was performed at 12 and 24 weeks postsurgery. Results: Statistically significant difference was observed between the clinical parameters at baseline and 12 and 24 weeks within the groups. There was no statistically significant difference, between the groups. Mean root coverage (RC was 80% ±29.1% in the DLSBF group and 78.8% ±37.6% in the DLSBF + PRF group with no statistically significant difference. Conclusion: From the results obtained in this study, the addition of PRF to DLSBF gives no additional benefits to the clinical parameters measured in RC.

Structural and biochemical analyses indicate that a bacterial persulfide dioxygenase–rhodanese fusion protein functions in sulfur assimilation

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Motl, Nicole; Skiba, Meredith A.; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma

2017-07-06

Hydrogen sulfide (H2S) is a signaling molecule that is toxic at elevated concentrations. In eukaryotes, it is cleared via a mitochondrial sulfide oxidation pathway, which comprises sulfide quinone oxidoreductase, persulfide dioxygenase (PDO), rhodanese, and sulfite oxidase and converts H2S to thiosulfate and sulfate. Natural fusions between the non-heme iron containing PDO and rhodanese, a thiol sulfurtransferase, exist in some bacteria. However, little is known about the role of the PDO–rhodanese fusion (PRF) proteins in sulfur metabolism. Herein, we report the kinetic properties and the crystal structure of a PRF from the Gram-negative endophytic bacterium Burkholderia phytofirmans. The crystal structures of wild-type PRF and a sulfurtransferase-inactivated C314S mutant with and without glutathione were determined at 1.8, 2.4, and 2.7 Å resolution, respectively. We found that the two active sites are distant and do not show evidence of direct communication. The B. phytofirmans PRF exhibited robust PDO activity and preferentially catalyzed sulfur transfer in the direction of thiosulfate to sulfite and glutathione persulfide; sulfur transfer in the reverse direction was detectable only under limited turnover conditions. Together with the kinetic data, our bioinformatics analysis reveals that B. phytofirmans PRF is poised to metabolize thiosulfate to sulfite in a sulfur assimilation pathway rather than in sulfide stress response as seen, for example, with the Staphylococcus aureus PRF or sulfide oxidation and disposal as observed with the homologous mammalian proteins.

Clinical and radiographic comparison of platelet-rich fibrin and mineral trioxide aggregate as pulpotomy agents in primary molars

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Surendra Patidar

2017-01-01

Full Text Available Aim: This study aimed to evaluate and compare the Platelet-rich fibrin (PRF and Mineral trioxide aggregate (MTA as a pulpotomy agent in primary molars. Material and Methods: In this study, 50 primary molars from 50 healthy children aged 5–9 years requiring pulpotomy were randomly allocated into two groups. In PRF group, after coronal pulp removal and hemostasis, remaining pulp tissue was covered with PRF preparation. In the MTA group, the pulp stumps were covered with MTA (Pro Root MTA-Root Canal Repair Material, Dentsply International Inc. paste obtained by mixing MTA powder with sterile water at a 3:1 powder to water ratio. All teeth were restored with reinforced zinc oxide eugenol base and glass – ionomer cement. Stainless steel crowns were given in both groups 24 h after treatment. Clinical evaluation was undertaken at 1, 3, and 6 months intervals whereas radiographic evaluation of the treated teeth was carried out at the interval of 6 months. Results: By the end of 6 months, the overall success rate was 90% in PRF group and 92% in MTA Group. A statistically significant difference was observed between the groups at 6 months of follow-up (P 0.05. Conclusion: Radiographic and clinical outcome in PRF group could suggest it as an acceptable alternative in pulpotomy of primary teeth. PRF holds a promising future in the area of primary tooth vital pulp therapy.

Polyphenol-rich food general and on pregnancy effects: a review.

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Hahn, Marla; Baierle, Marília; Charão, Mariele F; Bubols, Guilherme B; Gravina, Fernanda S; Zielinsky, Paulo; Arbo, Marcelo D; Cristina Garcia, Solange

2017-07-01

This review aimed to investigate possible protective or deleterious effects of polyphenol-rich foods (PRF) on chronic diseases, e.g. cardiovascular, and in pregnant women, along with their antioxidant and anti-inflammatory action. A great variety of foods and beverages, such as herbal teas, grape and orange derivatives, dark chocolate, and many others contain high concentrations of flavonoids and are freely consumed by the general population. In humans, PRF consumption reduces lipid peroxidation, and several studies have shown a positive correlation between an increased consumption of PRF and a decrease in the incidence of cardiovascular disease. On the other hand, current studies have suggested that maternal ingestion of PRF, especially during the third trimester of pregnancy, could be associated to fetal ductal constriction (DC). Fetuses exposed to this type of diet show higher ductal velocities and lower pulsatility indexes, as well as larger right ventricles than those exposed to minimal amounts of these substances. The underlying mechanism involved in these conditions has not been entirely elucidated, but it seems to be a result of the antioxidant and anti-inflammatory effects of polyphenols by some pathway. Furthermore, taking into account the deleterious effect in late-pregnancy against the numerous positive effects associated to polyphenols, this dual behavior deserves attention particularly to control the dietary ingestion of PRF during gestation. In this line, same PRF, natural constituents of human diet, may represent risk to fetal in late pregnancy compared to the use of nonsteroidal anti-inflammatory drugs.

Platelet rich fibrin and xenograft in treatment of intrabony defect

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Saurav Panda

2014-01-01

Full Text Available For complete periodontal regeneration, delivery of growth factors in the local environment holds a great deal in adjunct to bone grafts. Platelet rich fibrin (PRF is considered as second generation platelet concentrate, consisting of viable platelets, releasing various growth factors such as platelet-derived growth factor, vascular endothelial growth factor, transforming growth factor, insulin-like growth factor, epidermal growth factor and basic fibroblast growth factor. Hence, this case report aims to investigate the clinical and radiological (bone fill effectiveness of autologous PRF along with the use of xenogenic bone mineral in the treatment of intra bony defects. Intrabony defect was treated with autologous PRF along with the use of xenogenic bone mineral. A decrease in probing pocket depth, gain in clinical attachment level and significant bone fill was observed at end of 6 months. The result obtained with the use of PRF may be attributed to the sustained and simultaneous release of various growth factors over a period of 7 days. In this case report, the positive clinical impact of additional application of PRF with xenogenic graft material in the treatment of periodontal intrabony defect was seen.

Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

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Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

2016-09-01

To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

Magnetic resonance thermometry for monitoring photothermal effects of interstitial laser irradiation

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Goddard, Jessica; Jose, Jessnie; Figueroa, Daniel; Le, Kelvin; Liu, Hong; Nordquist, Robert E.; Hode, Tomas; Chen, Wei R.

2012-03-01

Selective photothermal interaction using dye-assisted non-invasive laser irradiation has limitations when treating deeper tumors or when the overlying skin is heavily pigmented. We developed an interstitial laser irradiation method to induce the desired photothermal effects. An 805-nm near-infrared laser with a cylindrical diffuser was used to treat rat mammary tumors by placing the active tip of the fiber inside the target tumors. Three different power settings (1.0 to 1.5 watts) were applied to treat animal tumors with an irradiation duration of 10 minutes. The temperature distributions of the treated tumors were measured by a 7.1-Tesla magnetic resonance imager using proton resonance frequency (PRF) method. Three-dimensional temperature profiles were reconstructed and assessed using PRF. This is the first time a 7.1-Tesla magnetic resonance imager has been used to monitor interstitial laser irradiation via PRF. This study provides a basic understanding of the photothermal interaction needed to control the thermal damage inside tumor using interstitial laser irradiation. It also shows that PRF can be used effectively in monitoring photothermal interaction. Our long-term goal is to develop a PRF-guided laser therapy for cancer treatment.

Transient Sensory Recovery in Stroke Patients After Pulsed Radiofrequency Electrical Stimulation on Dorsal Root Ganglia: A Case Series.

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Apiliogullari, Seza; Gezer, Ilknur A; Levendoglu, Funda

2017-01-01

The integrity of the somatosensory system is important for motor recovery and neuroplasticity after strokes. Peripheral stimulation or central stimulation in patients with central nervous system lesions can be an effective modality in improving function and in facilitating neuroplasticity. We present 2 hemiplegic cases with sensory motor deficit and the result of the pulsed radiofrequency (PRF) electrical stimulation to the dorsal root ganglia. After PRF electrical stimulation, significant improvement was achieved in the examination of patients with superficial and deep sensation. However, during the follow-up visits were observed that the effect of PRF electrical stimulation disappeared. We believe that these preliminary results could be used in the development of future prospective cohort studies and randomized controlled trials that focus on the effect of PRF electrical stimulation on dorsal root ganglia to treat sensory deficits in poststroke patients.

Ultra-wideband short-pulse radar with range accuracy for short range detection

Energy Technology Data Exchange (ETDEWEB)

Rodenbeck, Christopher T; Pankonin, Jeffrey; Heintzleman, Richard E; Kinzie, Nicola Jean; Popovic, Zorana P

2014-10-07

An ultra-wideband (UWB) radar transmitter apparatus comprises a pulse generator configured to produce from a sinusoidal input signal a pulsed output signal having a series of baseband pulses with a first pulse repetition frequency (PRF). The pulse generator includes a plurality of components that each have a nonlinear electrical reactance. A signal converter is coupled to the pulse generator and configured to convert the pulsed output signal into a pulsed radar transmit signal having a series of radar transmit pulses with a second PRF that is less than the first PRF.

Platelet-rich fibrin: a boon in regenerative endodontics.

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Rebentish, Priyanka D; Umashetty, Girish; Kaur, Harpreet; Doizode, Trupthi; Kaslekar, Mithun; Chowdhury, Shouvik

2016-12-01

Research into regenerative dentistry has contributed momentum to the field of molecular biology. Periapical surgery aims at removing periapical pathology to achieve complete wound healing and regeneration of bone and periodontal tissue. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. Platelet-rich fibrin (PRF) is a wonderful tissue-engineering product and has recently gained much popularity due its promising results in wound healing bone induction. The features of this product are an attribute of platelets which, after cellular interactions, release growth factors and have shown application in diverse disciplines of dentistry. This paper is intended to shed light onto the various prospects of PRF and to provide clinical insight into regenerative endodontic therapy.

RESEARCH OF THE MAIN FORMS OF REFINANCING OF RECEIVABLES OF THE ENTERPRISES AT THE PRESENT STAGE

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I. V. Sukhomlin

2014-04-01

Full Text Available In article modern forms of refinancing of receivables for management of enterprise mutual settlements are investigated, namely: factoring, the accounting of the bills issued by buyers of production, forfeyting, the commercial credit. Advantages of the enterprises are defined at application of factoring operations. Characteristic signs of a forfeyting are defined, its advantages are analysed. Expediency of introduction of the commercial credit on the basis of circulation of bills is analysed.Purpose. To investigate modern forms of refinancing of receivables and to consider possibility of their use at the enterprise. To analyse influence of factoring operations on activity of the enterprises. To define expediency of introduction of the commercial credit on the basis of circulation of bills.Method or methodology of carrying out work. Work is performed by results of research of modern domestic and foreign views on advantages of use of the main forms of refinancing of receivables of the enterprises as means of increase of solvency at the present stage.Results. The main forms of refinancing of receivables, including such as are investigated: factoring, forfeyting, commercial credit. Advantages of the enterprises are defined at application of factoring operations. Characteristic signs of a forfeyting are considered, its advantages are analysed. Expediency of introduction of the commercial credit on the basis of circulation of bills is defined.Scope of results. The recommendations offered in article can be used by the enterprises of Ukraine of all forms of ownership for solvency increase at the present stage.Purchase on Elibrary.ru > Buy now

Transformative Learning and the Form That Transforms: Towards a Psychosocial Theory of Recognition Using Auto/ Biographical Narrative Research

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West, Linden

2014-01-01

In this article, I interrogate the changing forms that may be fundamental to transformative learning and how these are best chronicled and understood. Drawing on auto/biographical narrative research, I challenge the continuing primacy of a kind of overly disembodied, decontextualized cognition as the basis of transformation. Notions of epistemic…

Pulsed Radiofrequency Treatment of Complex Regional Pain Syndrome: A Case Series

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Vlad Djuric

2014-01-01

Full Text Available BACKGROUND: Various forms of sympathetic chain neurolysis (sympathectomy have, at one time or another, held promise as effective treatment options for complex regional pain syndrome (CRPS. Complications, such as worsening pain and the development of new pain syndromes, have prevented sympathectomy from emerging as a standard intervention. In an effort to avoid poor outcomes associated with neurolysis, pulsed radiofrequency (PRF has been proposed as a potential treatment alternative for a number of chronic neuropathic pain states, including some forms of CRPS.

Precise Intradermal Injection of Nanofat-Derived Stromal Cells Combined with Platelet-Rich Fibrin Improves the Efficacy of Facial Skin Rejuvenation

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Zhi-Jie Liang

2018-05-01

Full Text Available Background/Aims: The rejuvenation properties of nanofat grafting have been described in recent years. However, it is not clear whether the clinical efficacy of the procedure is attributable to stem cells or linked to other components of adipose tissue. In this study we isolated nanofat-derived stem cells (NFSCs to observe their biological characteristics and evaluate the efficacy of precise intradermal injection of nanofat combined with platelet-rich fibrin (PRF in patients undergoing facial rejuvenation treatment. Methods: Third-passage NFSCs were isolated and cultured using a mechanical emulsification method and their surface CD markers were analyzed by flow cytometry. The adipogenic and osteogenic nature and chondrogenic differentiation capacity of NFSCs were determined using Oil Red O staining, alizarin red staining, and Alcian blue staining, respectively. Paracrine function of NFSCs was evaluated by enzyme-linked immunosorbent assay (ELISA at 1, 3, 7, 14, and 28 days after establishing the culture. Then, the effects of PRF on NFSC proliferation were assessed in vitro. Finally, we compared the outcome in 103 patients with facial skin aging who underwent both nanofat and intradermal PRF injection (treatment group and 128 patients who underwent hyaluronic acid (HA injection treatment (control group. Outcomes in the two groups were compared by assessing pictures taken at the same angle before and after treatment, postoperative recovery, incidence of local absorption and cysts, and skin quality before treatment, and at 1, 12, 24 months after treatment using the VISIA Skin Image Analyzer and a SOFT5.5 skin test instrument. Results: NFSCs expressed CD29, CD44, CD49d, CD73, CD90, and CD105, but did not express CD34, CD45, and CD106. NFSCs also differentiated into adipocytes, osteoblasts, and chondrocytes under appropriate induction conditions. NFSCs released large amounts of growth factors such as VEGF, bFGF, EGF, and others, and growth factor

Review on Cold-Formed Steel Connections

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Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

2014-01-01

The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

Obtention of injectable platelets rich-fibrin (i-PRF) and its polymerization with bone graft: technical note.

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Mourão, Carlos Fernando de Almeida Barros; Valiense, Helder; Melo, Elias Rodrigues; Mourão, Natália Belmock Mascarenhas Freitas; Maia, Mônica Diuana-Calasans

2015-01-01

The use of autologous platelet concentrates, represent a promising and innovator tools in the medicine and dentistry today. The goal is to accelerate hard and soft tissue healing. Among them, the platelet-rich plasma (PRP) is the main alternative for use in liquid form (injectable). These injectable form of platelet concentrates are often used in regenerative procedures and demonstrate good results. The aim of this study is to present an alternative to these platelet concentrates using the platelet-rich fibrin in liquid form (injectable) and its use with particulated bone graft materials in the polymerized form.

Obtention of injectable platelets rich-fibrin (i-PRF and its polymerization with bone graft: technical note

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Carlos Fernando de Almeida Barros Mourão

Full Text Available The use of autologous platelet concentrates, represent a promising and innovator tools in the medicine and dentistry today. The goal is to accelerate hard and soft tissue healing. Among them, the platelet-rich plasma (PRP is the main alternative for use in liquid form (injectable. These injectable form ofplatelet concentrates are often used in regenerative procedures and demonstrate good results. The aim of this study is to present an alternative to these platelet concentrates using the platelet-rich fibrin in liquid form (injectable and its use with particulated bone graft materials in the polymerized form.

Associations between the expression of epigenetically regulated genes and the expression of DNMTs and MBDs in systemic lupus erythematosus.

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Eva Balada

Full Text Available OBJECTIVES: We determined the expression of ITGAL, PRF1, KIR2DL4, CD70, and CD40LG in patients with SLE and performed correlations with the global DNA methylation status and the levels of three DNA methylation enzymes and two methyl CpG-binding domain (MBD proteins. PATIENTS AND METHODS: CD4(+ T cells were isolated from 35 SLE patients and 30 healthy controls. DNA deoxymethylcytosine content was measured by an enzyme-linked immunosorbent assay (ELISA. Transcript levels of ITGAL, PRF1, KIR2DL4, CD70, CD40LG, DNMT1, DNMT3A, DNMT3B, MBD2, and MBD4 were quantified by real-time reverse-transcription polymerase chain reaction (RT-PCR. RESULTS: SLE patients had significantly elevated transcript levels of ITGAL (18.61±22.17 vs. 7.33±9.17, p = 0.042, PRF1 (21.67±26.34 vs. 10.67±11.65, p = 0.039, and CD70 (1.45±1.63 vs. 0.67±0.28, p = 0.011. A positive correlation was observed between transcript levels of CD40LG and ITGAL (r = 0.477, p = 0.004 as well as between CD40LG and PRF1 (r = 0.557, p = 0.001. Transcript levels of KIR2DL4 were higher than controls' but it did not reach statistical significance (1.36±3.52 vs. 0.22±0.79, p = 0.560. A tight relationship with global DNA hypomethylation as well as with the expression of most of the DNA methylation-related genes was observed, especially for ITGAL, PRF1, and CD40LG. CONCLUSIONS: ITGAL, PRF1, and CD70 are overexpressed in SLE CD4(+ T cells. The tight association of CD40LG with ITGAL and PRF1 leads us to infer that it probably contributes to the pathogenesis of the disease. The apparent simultaneous regulation between their expression and the global DNA hypomethylation as well as with the transcription of many DNA methylation-related enzymes, reinforces the idea that epigenetic mechanisms are responsible for the deregulation of ITGAL, PRF1, and CD40LG.

Memoir as a Form of Auto-Ethnographic Research for Exploring the Practice of Transnational Higher Education in China

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Scott, Joy Denise

2014-01-01

In this paper, I argue that memoir, as a form of auto-ethnographic research, is an appropriate method for exploring the complexities and singularities in the practice of western educational practitioners who are immersed in the social reality of offshore higher education institutions, such as those in Mainland China. I illustrate this proposition…

Effects of Plasma Rich in Growth Factors and Platelet-Rich Fibrin on Proliferation and Viability of Human Gingival Fibroblasts

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Vahabi, Surena; Vaziri, Shahram; Torshabi, Maryam

2015-01-01

Objectives: Platelet preparations are commonly used to enhance bone and soft tissue regeneration. Considering the existing controversies on the efficacy of platelet products for tissue regeneration, more in vitro studies are required. The aim of the present study was to compare the in vitro effects of plasma rich in growth factors (PRGF) and platelet-rich fibrin (PRF) on proliferation and viability of human gingival fibroblasts (HGFs). Materials and Methods: Anitua’s PRGF and Choukran’s PRF were prepared according to the standard protocols. After culture periods of 24, 48 and 72 hours, proliferation of HGFs was evaluated by the methyl thiazol tetrazolium assay. Statistical analysis was performed using one-way ANOVA followed by Tukey-Kramer’s multiple comparisons and P-valuesPRGF treatment induced statistically significant (PPRGF than in PRF group (PPRGF had a strong stimulatory effect on HGF cell viability and proliferation compared to PRF. PMID:26877740

Maximizing entropy of image models for 2-D constrained coding

DEFF Research Database (Denmark)

Forchhammer, Søren; Danieli, Matteo; Burini, Nino

2010-01-01

This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite...... context models, which define stationary probability distributions on finite rectangles and thus allow for calculation of the entropy. We consider two binary constraints and revisit the hard square constraint given by forbidding neighboring 1s and provide novel results for the constraint that no uniform 2...... £ 2 squares contains all 0s or all 1s. The maximum values of the entropy for the constraints are estimated and binary PRF satisfying the constraint are characterized and optimized w.r.t. the entropy. The maximum binary PRF entropy is 0.839 bits/symbol for the no uniform squares constraint. The entropy...

Conjoint Forming - Technologies for Simultaneous Forming and Joining

International Nuclear Information System (INIS)

Groche, P; Wohletz, S; Mann, A; Krech, M; Monnerjahn, V

2016-01-01

The market demand for new products optimized for e. g. lightweight applications or smart components leads to new challenges in production engineering. Hybrid structures represent one promising approach. They aim at higher product performance by using a suitable combination of different materials. The developments of hybrid structures stimulate the research on joining of dissimilar materials. Since they allow for joining dissimilar materials without external heating technologies based on joining by plastic deformation seem to be of special attractiveness. The paper at hand discusses the conjoint forming approach. This approach combines forming and joining in one process. Two or more workpieces are joined while at least one workpiece is plastically deformed. After presenting the fundamental joining mechanisms, the conjoint forming approach is discussed comprehensively. Examples of conjoint processes demonstrate the effectiveness and reveal the underlying phenomena. (paper)

Evaluation of postoperative pulmonary regurgitation after surgical repair of tetralogy of Fallot: comparison between Doppler echocardiography and MR velocity mapping

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Grothoff, Matthias; Spors, Birgit; Gutberlet, Matthias [Charite Campus Virchow Klinikum, Department of Radiology and Nuclear Medicine, Berlin (Germany); Abdul-Khaliq, Hasim [Deutsches Herzzentrum, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin (Germany)

2008-02-15

Pulmonary regurgitation is a common finding in patients after correction of tetralogy of Fallot (TOF). Right ventricular impairment and even ventricular arrhythmia have been ascribed to pulmonary valve insufficiency (PI), which is therefore an important issue in follow-up examinations. To compare PI measured by echocardiography (ECHO) with data provided by cardiac MRI (CMR). We studied 54 selected patients (18 female; median age 14.0 years, range 3.8-53.4 years) after surgical correction of TOF. To quantify pulmonary regurgitant fraction (PRF) by CMR, flow velocity mapping was performed. On Doppler ECHO, length, width and localization of regurgitant flow was measured. The severity of PI was categorized as mild, moderate or severe and compared to the data obtained by CMR. On CMR the mean PRF was 29.2 {+-} 13.4%. Patients with a transannular patch had a significantly higher PRF (39.9 {+-} 11.6%) than patients with an intact annular ring (23.6 {+-} 11.4%). Differentiation by Doppler ECHO between the categories mild, moderate and severe PI was confirmed by significant differences in PRF measured by CMR (mild vs. moderate P < 0.04; moderate vs. severe P < 0.014; mild vs. severe P < 0.001). Furthermore, PRF correlated with right ventricular end diastolic volume index (r = 0.45, P < 0.01) and right ventricular end systolic volume index (r = 0.39, P < 0.01). Doppler ECHO can estimate the severity of PI after repair of TOF with acceptable results compared to CMR flow measurement. In univariate analysis there is only a weak influence of PRF on right ventricular volume. (orig.)

Management of refractory trigeminal neuralgia using extended duration pulsed radiofrequency application.

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Thapa, Deepak; Ahuja, Vanita; Dass, Christopher; Verma, Parul

2015-01-01

Trigeminal neuralgia (TN) produces incapacitating facial pain that reduces quality of life in patients. Thermal radiofrequency (RF) ablation of gasserian ganglion (GG) is associated with masseter weakness and unpleasant sensations along the distribution of the ablated nerve. Pulsed radiofrequency (PRF) of GG has minimal side effects but literature is inconclusive regarding its benefit in refractory TN. Increasing the duration of PRF application to 6 minutes in TN produced encouraging results. PRF application to the saphenous nerve for 8 minutes reported improved pain relief and patient satisfaction. We report successful management of two patients of classic TN, which were refractory to medical management and interventional nerve blocks. The lesion site were confirmed with motor and sensory stimulation through a 22 G, 10 cm RF needle with 5 mm active tip. Both the patients received four cycles of PRF at 42 °C with each cycle of 120 seconds (8 minutes). The visual analogue scale (VAS) in case 1 reduced from pre-block score of 80 to score 10 post-block, while in case 2 the VAS reduced from pre-block score of 85 to score 15 post-block. During follow up both the patients are now pain free with minimal dose of carbamazepine at 12 and 6 months respectively. We used PRF for longer duration (8 minutes) in these patients, which resulted in improved VAS and WHOQOL-BREF score in these patients. PRF of mandibular division of GG for extended duration provided long-term effective pain relief and quality of life in patients of refractory classic TN.

Platelet concentration in platelet concentrates and periodontal regeneration-unscrambling the ambiguity

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A Suchetha

2015-01-01

Full Text Available Context: Platelet-rich-plasma (PRP and Platelet-rich-fibrin (PRF are extensively used autologous platelet concentrates in periodontal regeneration, and PRF has a better efficacy as compared to PRP. The rationale for this difference has often been attributed to the difference in the structure of the fibrin matrix. However, the effect of concentration of platelets on the regenerative potential of these concentrates is obscure. Aims: The study was conducted to evaluate and compare, clinically and radiographically, the efficacy of PRF and PRP in the treatment of periodontal endosseous defects and to assess the effect of platelet concentration on periodontal regeneration. Materials and Methods: Twenty intrabony defects were selected and divided into two groups randomly by the coin toss method. Group I received PRP and Group II subjects were treated with PRF. The platelet counts in PRP and PRF were analyzed. Clinical and radiological parameters were assessed at baseline and 3, 6, and 9 months postoperatively. Statistical Analysis: Kruskal–Wallis Chi-square test, Wilcoxon signed rank test, t-test, and Spearman's rank correlation were used for statistical analysis of data. Results: There was statistically significant improvement in all the parameters in the two groups except in relation to gingival recession. There was a statistically significant difference between the platelet count in Group I and Group II (P = 0.002. Conclusion: PRP and PRF appear to have nearly comparable effects in terms of periodontal regeneration. The concentration of platelets appears to play a paradoxical role in regeneration. The regenerative potential of platelets appears to be optimal within a limited range.

Efficacy of Platelet-Rich Fibrin After Mandibular Third Molar Extraction: A Systematic Review and Meta-Analysis.

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Al-Hamed, Faez Saleh; Tawfik, Mohamed Abdel-Monem; Abdelfadil, Ehab; Al-Saleh, Mohammed A Q

2017-06-01

To assess the effect of platelet-rich fibrin (PRF) on the healing process of the alveolar socket after surgical extraction of the mandibular third molars. PubMed, the Cochrane Central Register of Controlled Trials, Scopus, and relevant journals were searched using a combination of specific keywords ("platelet-rich fibrin," "oral surgery," and "third molar"). The final search was conducted on November 2, 2015. Randomized controlled clinical trials, as well as controlled clinical trials, aimed at comparing the effect of PRF versus natural healing after extraction of mandibular third molars were included. Five randomized controlled trials and one controlled clinical trial were included. There were 335 extractions (168 with PRF and 167 controls) in 183 participants. Considerable heterogeneity in study characteristics, outcome variables, and estimated scales was observed. Positive results were generally recorded for pain, trismus, swelling, periodontal pocket depth, soft tissue healing, and incidence of localized osteitis, but not in all studies. However, no meta-analysis could be conducted for such variables because of the different measurement scales used. The qualitative and meta-analysis results showed no significant improvement in bone healing with PRF-treated sockets compared with the naturally healing sockets. Within the limitations of the available evidence, PRF seems to have no beneficial role in bone healing after extraction of the mandibular third molars. Future standardized randomized controlled clinical trials are required to estimate the effect of PRF on socket regeneration. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

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Yutaka Kitamura

2018-02-01

Full Text Available Platelet-rich fibrin (PRF clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

Micro metal forming

CERN Document Server

2013-01-01

Micro Metal Forming, i. e. forming of parts and features with dimensions below 1 mm, is a young area of research in the wide field of metal forming technologies, expanding the limits for applying metal forming towards micro technology. The essential challenges arise from the reduced geometrical size and the increased lot size. In order to enable potential users to apply micro metal forming in production, information about the following topics are given: tribological behavior: friction between tool and work piece as well as tool wear mechanical behavior: strength and formability of the work piece material, durability of the work pieces size effects: basic description of effects occurring due to the fact, that the quantitative relation between different features changes with decreasing size process windows and limits for forming processes tool making methods numerical modeling of processes and process chains quality assurance and metrology All topics are discussed with respect to the questions relevant to micro...

A rapid seedling resistance assay identifies wild tomato lines that are resistant to Psuedomonas syringe pv. tomato race 1

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Bacterial speck caused by Pseudomonas syringae has historically been controlled by the Pto/Prf gene cluster. Emerging strains like P. syringae pv. tomato race 1 overcome resistance conferred by Pto/Prf, and can cause serious crop loss under appropriate environmental conditions. We developed a rapid ...

Working Memory and Reinforcement Schedule Jointly Determine Reinforcement Learning in Children: Potential Implications for Behavioral Parent Training

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Elien Segers

2018-03-01

Full Text Available Introduction: Behavioral Parent Training (BPT is often provided for childhood psychiatric disorders. These disorders have been shown to be associated with working memory impairments. BPT is based on operant learning principles, yet how operant principles shape behavior (through the partial reinforcement (PRF extinction effect, i.e., greater resistance to extinction that is created when behavior is reinforced partially rather than continuously and the potential role of working memory therein is scarcely studied in children. This study explored the PRF extinction effect and the role of working memory therein using experimental tasks in typically developing children.Methods: Ninety-seven children (age 6–10 completed a working memory task and an operant learning task, in which children acquired a response-sequence rule under either continuous or PRF (120 trials, followed by an extinction phase (80 trials. Data of 88 children were used for analysis.Results: The PRF extinction effect was confirmed: We observed slower acquisition and extinction in the PRF condition as compared to the continuous reinforcement (CRF condition. Working memory was negatively related to acquisition but not extinction performance.Conclusion: Both reinforcement contingencies and working memory relate to acquisition performance. Potential implications for BPT are that decreasing working memory load may enhance the chance of optimally learning through reinforcement.

Nano-biphasic calcium phosphate/polyvinyl alcohol composites with enhanced bioactivity for bone repair via low-temperature three-dimensional printing and loading with platelet-rich fibrin.

Science.gov (United States)

Song, Yue; Lin, Kaifeng; He, Shu; Wang, Chunmei; Zhang, Shuaishuai; Li, Donglin; Wang, Jimeng; Cao, Tianqing; Bi, Long; Pei, Guoxian

2018-01-01

As a newly emerging three-dimensional (3D) printing technology, low-temperature robocasting can be used to fabricate geometrically complex ceramic scaffolds at low temperatures. Here, we aimed to fabricate 3D printed ceramic scaffolds composed of nano-biphasic calcium phosphate (BCP), polyvinyl alcohol (PVA), and platelet-rich fibrin (PRF) at a low temperature without the addition of toxic chemicals. Corresponding nonprinted scaffolds were prepared using a freeze-drying method. Compared with the nonprinted scaffolds, the printed scaffolds had specific shapes and well-connected internal structures. The incorporation of PRF enabled both the sustained release of bioactive factors from the scaffolds and improved biocompatibility and biological activity toward bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. Additionally, the printed BCP/PVA/PRF scaffolds promoted significantly better BMSC adhesion, proliferation, and osteogenic differentiation in vitro than the printed BCP/PVA scaffolds. In vivo, the printed BCP/PVA/PRF scaffolds induced a greater extent of appropriate bone formation than the printed BCP/PVA scaffolds and nonprinted scaffolds in a critical-size segmental bone defect model in rabbits. These experiments indicate that low-temperature robocasting could potentially be used to fabricate 3D printed BCP/PVA/PRF scaffolds with desired shapes and internal structures and incorporated bioactive factors to enhance the repair of segmental bone defects.

Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes

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Hooman Khorshidi

2016-01-01

Full Text Available Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1 and the rest was used to get a membrane by PRGF-Endoret system (group 2. Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P0.05. Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here.

Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes.

Science.gov (United States)

Khorshidi, Hooman; Raoofi, Saeed; Bagheri, Rafat; Banihashemi, Hodasadat

2016-01-01

Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF) versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1) and the rest was used to get a membrane by PRGF-Endoret system (group 2). Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P 0.05). Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here.

Effect of Platelet-Rich Fibrin on Peripheral Nerve Regeneration.

Science.gov (United States)

Şenses, Fatma; Önder, Mustafa E; Koçyiğit, Ismail D; Kul, Oğuz; Aydin, Gülümser; Inal, Elem; Atil, Fethi; Tekin, Umut

2016-10-01

This study aimed to evaluate the effect of platelet-rich fibrin (PRF) on peripheral nerve regeneration on the sciatic nerve of rats by using functional, histopathologic, and electrophysiologic analyses. Thirty female Wistar rats were divided randomly into 3 experimental groups. In group 1 (G1), which was the control group, the sciatic nerve was transected and sutured (n = 10). In group 2 (G2), the sciatic nerve was transected, sutured, and then covered with PRF as a membrane (n = 10). In group 3 (G3), the sciatic nerve was transected, sutured by leaving a 5-mm gap, and then covered by PRF as a nerve guide (n = 10). Functional, histopathologic, and electrophysiologic analyses were performed. The total histopathologic semiquantitative score was significantly higher in G1 compared to G2 and G3 (P < 0.05). Myelin thickness and capillaries were significantly lower in G3 compared to G1 (P < 0.05). There was no statistically significant difference between the groups with regard to the functional and electrophysiologic results. The study results suggest that PRF decreases functional recovery in sciatic nerve injury. Further studies are required to determine the efficacy of PRF on peripheral nerve regeneration.

[Ethics in clinical research: contextualizing and reductionist problem definitions, forms of ethical reflection and some particular implications].

Science.gov (United States)

Roelcke, Volker

2003-12-01

The present paper starts off with a short outline of issues, conflicts, and goals of ethical reflection about clinical research. It is then argued that non-reductionist, patient-centred ethics should critically reflect on medically preformed problem definitions, ways of problem solution, and evaluations. The shortcomings of such preformed perceptions and interpretations are illustrated using the examples of dementia research, and the complexities of the notion of risk. A more comprehensive approach including the perceptions, interpretations, and evaluations of the patients' perspective necessitates a form of ethical reflection which takes into account the social and cultural contexts of clinical research, and which therefore relies on concepts and methods of the cultural sciences (in particular history, sociology, and cultural anthropology). The decision for a reductionist, or for a contextualising mode of ethical reflection represents in itself a value decision and needs to be explicitly justified.

Bioactivity and stability of endogenous fibrogenic factors in platelet-rich fibrin

DEFF Research Database (Denmark)

Lundquist, R.; Dziegiel, M.H.; Agren, M.S.

2008-01-01

Platelet-rich fibrin (PRF) is an autologous fibrin sealant (FS) enriched with a platelet concentrate (> 1,000,000 platelets/microL) produced by the automated Vivostat system and used to enhance wound healing. The effects of PRF were compared with supernatant from thrombin-activated platelet conce...

Pulsed Radiofrequency Application for the Treatment of Pain Secondary to Sacroiliac Joint Metastases.

Science.gov (United States)

Yi, Yu Ri; Lee, Na Rea; Kwon, Young Suk; Jang, Ji Su; Lim, So Young

2016-01-01

Sacroiliac (SI) joint pain can result from degeneration, infection, malignancy, and trauma. Patients with metastatic bone pain who do not respond to conventional treatment may need more aggressive neuroinvasive approaches. Recently, pulsed radiofrequency (PRF) neuromodulation has emerged as a promising treatment alternative for refractory cases of SI joint pain. Nevertheless, there is no report on the treatment of pain arising from SI joint metastases with PRF. We are reporting about a 63-year-old woman suffering from buttock pain due to breast cancer metastases in the SI joint. We treated this patient with PRF neuromodulation of the L4-S3 primary dorsal rami and lateral branches using a rotating curved needle technique. The patient tolerated the procedures well, without any complications. She experienced about 70% reduction in pain, and pain relief was sustained for 10 months. This result suggests that PRF neuromodulation is a safe, effective treatment for pain from SI joint metastases.

Antimicrobial effect of platelet-rich plasma and platelet-rich fibrin.

Science.gov (United States)

Badade, Pallavi S; Mahale, Swapna A; Panjwani, Alisha A; Vaidya, Prutha D; Warang, Ayushya D

2016-01-01

Platelet concentrates have been extensively used in a variety of medical fields to promote soft- and hard-tissue regeneration. The significance behind their use lies in the abundance of growth factors (GFs) in platelets α-granules that promote wound healing. Other than releasing a pool of GFs upon activation, platelets also have many features that indicate their role in the anti-infective host defense. The aim of this study is to evaluate the antimicrobial activities of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) against periodontal disease-associated bacteria. Blood samples were obtained from ten adult male patients. PRP and PRF were procured using centrifugation. The antimicrobial activity of PRP and PRF was evaluated by microbial culturing using bacterial strains of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. P. gingivalis and A. actinomycetemcomitans were inhibited by PRP but not by PRF. PRP is a potentially useful substance in the fight against periodontal pathogens. This might represent a valuable property in adjunct to the enhancement of tissue regeneration.

Platelet concentrates: Bioengineering dentistry′s regenerative dreams

Directory of Open Access Journals (Sweden)

Sushma Naag

2015-01-01

Full Text Available Technological advances in the fields of medicine and allied sciences had given much needed momentum into the field of molecular biology and regenerative medicine. They indeed provided a boost to innovate new yields for both hard tissue and soft tissue regeneration in dentistry. One among them is the use of platelet concentrates (platelet rich plasma [PRP], platelet rich fibrin [PRF]. Autologous concentrate of blood platelets with a suspension of growth factors offers an enhanced healing of hard and soft tissues. It is an auxiliary benefit for an operator to be aware of platelet concentrates and its healing properties for delivering unsurpassed oral health care to patients. The current article outlines the principles, objectives and clinical insight to the regenerative potential of platelet concentrates in various fields of dentistry. The search words of the PubMed data base were PRF and other permutations of keywords such as "PRP dentistry", PRF dentistry, PRF regenerative dentistry.

Role of plasma-rich fibrin in oral surgery

Directory of Open Access Journals (Sweden)

K Retna Kumar

2016-01-01

Full Text Available Platelet-rich fibrin (PRF is a fibrin meshwork, in which platelet cytokines, growth factors, and cells are entrapped and discharged after a period and can serve as a resorbable film. PRF is the next generation of platelet concentrates equipped to improve arrangement without biochemical blood handling; PRF is an evolution of the fibrin adhesive, which is widely used in the oral surgery. The guidelines of this innovation depend on concentrating platelets and growth factors in a plasma medium, and initiating them in a fibrin gel, keeping in mind the end goal to enhance the healing of wounds. Maxillary bone loss requires numerous regenerative techniques: as a supplement to the procedures of tissue regeneration, a platelet concentrate called PRF was tested for the 1st time in France by Dr. Choukroun. This article enriches the benefits and role of plasma-rich fibrin in oral surgery. Platelet-concentrate fibrin is an evolution of the fibrin glue, which is widely used in the oral surgery.

Recent package testing successes at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Ludwig, S.B.; Singley, P.T.; Michelhaugh, R.D.; Hawk, M.B.; Shappert, L.B.

2004-01-01

Oak Ridge National Laboratory (ORNL)'s history of testing of radioactive material packages dates back to the early 1960s, and includes the testing of hundreds of different packages of all shapes and sizes. This paper provides an overview of ORNL's new Packaging Research Facility (PRF) at the National Transportation Research Center (NTRC), and describes recent package testing successes conducted at the NTRC from September 2002 to September 2003

Combustion Homogeneity and Emission Analysis during the Transition from CI to HCCI for FACE I Gasoline

KAUST Repository

Vedharaj, S.

2017-10-10

Low temperature combustion concepts are studied recently to simultaneously reduce NOX and soot emissions. Optical studies are performed to study gasoline PPC in CI engines to investigate in-cylinder combustion and stratification. It is imperative to perform emission measurements and interpret the results with combustion images. In this work, we attempt to investigate this during the transition from CI to HCCI mode for FACE I gasoline (RON = 70) and its surrogate, PRF70. The experiments are performed in a single cylinder optical engine that runs at a speed of 1200 rpm. Considering the safety of engine, testing was done at lower IMEP (3 bar) and combustion is visualized using a high-speed camera through a window in the bottom of the bowl. From the engine experiments, it is clear that intake air temperature requirement is different at various combustion modes to maintain the same combustion phasing. While a fixed intake air temperature is required at HCCI condition, it varies at PPC and CI conditions between FACE I gasoline and PRF70. Three zones are identified 1) SOI = -180 to -80 CAD (aTDC) is HCCI zone 2) SOI = -40 to -20 CAD (aTDC) is PPC zone 3) After SOI = -15 CAD (aTDC) is CI zone. Combustion duration, ignition delay, start of combustion and CA90 (crank angle at which 90% of fuel burnt) are comparable between FACE I gasoline and PRF70. The combustion images show a prominent soot flame at CI condition, while only blue coloured premixed flames are visible at PPC condition for both the fuels. PRF70 seems to have a pronounced premixed effect when compared to FACE I gasoline at early injections, showing a decreased level of stratification. NOX emission and soot concentration decreases from CI condition and attains a constant zero value at HCCI condition for both FACE I gasoline and PRF70. CO and CO2 emissions matches between FACE I gasoline and PRF70 at PPC and CI condition, while CO emission is lower for PRF70 at HCCI condition.

Plasmids and rickettsial evolution: insight from Rickettsia felis.

Directory of Open Access Journals (Sweden)

Joseph J Gillespie

2007-03-01

Full Text Available The genome sequence of Rickettsia felis revealed a number of rickettsial genetic anomalies that likely contribute not only to a large genome size relative to other rickettsiae, but also to phenotypic oddities that have confounded the categorization of R. felis as either typhus group (TG or spotted fever group (SFG rickettsiae. Most intriguing was the first report from rickettsiae of a conjugative plasmid (pRF that contains 68 putative open reading frames, several of which are predicted to encode proteins with high similarity to conjugative machinery in other plasmid-containing bacteria.Using phylogeny estimation, we determined the mode of inheritance of pRF genes relative to conserved rickettsial chromosomal genes. Phylogenies of chromosomal genes were in agreement with other published rickettsial trees. However, phylogenies including pRF genes yielded different topologies and suggest a close relationship between pRF and ancestral group (AG rickettsiae, including the recently completed genome of R. bellii str. RML369-C. This relatedness is further supported by the distribution of pRF genes across other rickettsiae, as 10 pRF genes (or inactive derivatives also occur in AG (but not SFG rickettsiae, with five of these genes characteristic of typical plasmids. Detailed characterization of pRF genes resulted in two novel findings: the identification of oriV and replication termination regions, and the likelihood that a second proposed plasmid, pRFdelta, is an artifact of the original genome assembly.Altogether, we propose a new rickettsial classification scheme with the addition of a fourth lineage, transitional group (TRG rickettsiae, that is unique from TG and SFG rickettsiae and harbors genes from possible exchanges with AG rickettsiae via conjugation. We offer insight into the evolution of a plastic plasmid system in rickettsiae, including the role plasmids may have played in the acquirement of virulence traits in pathogenic strains, and the

Combustion Homogeneity and Emission Analysis during the Transition from CI to HCCI for FACE I Gasoline

KAUST Repository

Vedharaj, S.; Vallinayagam, R; An, Yanzhao; Izadi Najafabadi, Mohammad; Somers, Bart; Chang, Junseok; Johansson, Bengt

2017-01-01

Low temperature combustion concepts are studied recently to simultaneously reduce NOX and soot emissions. Optical studies are performed to study gasoline PPC in CI engines to investigate in-cylinder combustion and stratification. It is imperative to perform emission measurements and interpret the results with combustion images. In this work, we attempt to investigate this during the transition from CI to HCCI mode for FACE I gasoline (RON = 70) and its surrogate, PRF70. The experiments are performed in a single cylinder optical engine that runs at a speed of 1200 rpm. Considering the safety of engine, testing was done at lower IMEP (3 bar) and combustion is visualized using a high-speed camera through a window in the bottom of the bowl. From the engine experiments, it is clear that intake air temperature requirement is different at various combustion modes to maintain the same combustion phasing. While a fixed intake air temperature is required at HCCI condition, it varies at PPC and CI conditions between FACE I gasoline and PRF70. Three zones are identified 1) SOI = -180 to -80 CAD (aTDC) is HCCI zone 2) SOI = -40 to -20 CAD (aTDC) is PPC zone 3) After SOI = -15 CAD (aTDC) is CI zone. Combustion duration, ignition delay, start of combustion and CA90 (crank angle at which 90% of fuel burnt) are comparable between FACE I gasoline and PRF70. The combustion images show a prominent soot flame at CI condition, while only blue coloured premixed flames are visible at PPC condition for both the fuels. PRF70 seems to have a pronounced premixed effect when compared to FACE I gasoline at early injections, showing a decreased level of stratification. NOX emission and soot concentration decreases from CI condition and attains a constant zero value at HCCI condition for both FACE I gasoline and PRF70. CO and CO2 emissions matches between FACE I gasoline and PRF70 at PPC and CI condition, while CO emission is lower for PRF70 at HCCI condition.

Forms of address in Isizulu

OpenAIRE

2014-01-01

M.A. (African Studies) The study deals with forms of address in isiZulu. Therefore, the various aspects of speech that play roles when addressing a person, the factors affecting forms of address in isiZulu and the effect of languages such as English, Afrikaans and other African languages on the forms of address in isiZulu are of interest. Research was conducted on forms of address in isiZulu in parts of Soweto and it was discovered that form of address are determined by different factors i...

Use of platelet-rich fibrin and platelet-rich plasma in combination with fat graft: which is more effective during facial lipostructure?

Science.gov (United States)

Keyhan, Seied Omid; Hemmat, Seifollah; Badri, Amir Ali; Abdeshahzadeh, Arshad; Khiabani, Kazem

2013-03-01

Fat grafts have always represented a challenge in inducing the necessary neoangiogenesis, which results in significant resorption. This study was designed to compare the efficiency of first- and second-generation platelet-rich plasmas (PRPs) combined with a fat graft during facial lipostructure surgery. To address the research purpose, the investigators designed and implemented a double-blinded prospective clinical trial. The patients underwent bilateral facial lipostructure, a natural long-lasting method of filling and supporting the face using intricate layers of infiltrated autologous fat. The method involved the use of PRP on 1 side and platelet-rich fibrin (PRF) on the other side. The study population was composed of all patients presenting to the authors' department for the evaluation and management of facial contouring in the cheek and cheekbone areas from June 2008 through December 2010. The primary predictor variable was the type of combination (PRP/fat or PRF/fat). The outcome variables were the amount of resorption, which was estimated by comparing pre- and postsurgical photographic views, pain, edema, and bruising. The statistical evaluation of the findings was performed using SPSS software. Parametric tests (t test and Levene test) were used to compare the treatment efficacy and complications between the groups. Twenty-five patients (8 men and 17 women) underwent bilateral facial lipostructure surgery in the cheek and cheekbone areas using PRP and PRF. One year after the operation, a slight esthetic asymmetry was noticeable, with greater average resorption on the PRP/fat side. This first comparative clinical study highlights the value of using concentrated platelets for adipocyte grafts. The results suggest that the combination of fat and PRF is more effective than the combination of fat and PRP in the context of facial lipostructure surgery. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All

Deletion of the Ustilago maydis ortholog of the Aspergillus sporulation regulator medA affects mating and virulence through pheromone response

Science.gov (United States)

Mating of compatible haploid cells of Ustilago maydis is essential for infection and disease development in the host. For mating and subsequent filamentous growth and pathogenicity, the transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regul...

STUDI KOMPARASI KINERJA HULL FORM METODE SCHELTEMA DENGAN HULL FORM KAPAL IKAN TRADISIONAL TIPE DAERAH BATANG

OpenAIRE

A.F. Zakki; Parlindungan Manik

2012-01-01

This study comparation of hull form performance was analysed becaused there was suggestion that a ship was built by hull form scheming this time (Scheltema, Formdata, NPL Series) is better than a ship that was built traditionally because there is no basic erudite calculation in hull form design. So hull form design was result of natural adaptation. Such performance are ship’s resistance, stability, and ship’s navigation.This research about hull form performance is expected can giv...

Pulsed radiofrequency of the composite nerve supply to the knee joint as a new technique for relieving osteoarthritic pain: a preliminary report.

Science.gov (United States)

Vas, Lakshmi; Pai, Renuka; Khandagale, Nishigandha; Pattnaik, Manorama

2014-01-01

We report a new technique for pulsed radiofrequency (PRF) of the entire nerve supply of the knee as an option in treating osteoarthritis (OA) of knee. We targeted both sensory and motor nerves supplying all the structures around the knee: joint, muscles, and skin to address the entire nociception and stiffness leading to peripheral and central sensitization in osteoarthritis. Ten patients with pain, stiffness, and loss of function in both knees were treated with ultrasonography (USG) guided PRF of saphenous, tibial, and common peroneal nerves along with subsartorial, peripatellar, and popliteal plexuses. USG guided PRF of the femoral nerve was also done to address the innervation of the quadriceps muscle. Assessment of pain (Numerical Rating Scale [NRS], pain DETECT, knee function [Western Ontario and McMaster Universities Osteoarthritis Index- WOMAC]) were documented pre and post PRF at 3 and 6 months. Knee radiographs (Kellgren-Lawrence [K-L] grading) were done before PRF and one week later. All the patients showed a sustained improvement of NRS, pain DETECT, and WOMAC at 3 and 6 months. The significant improvement of patellar position and tibio-femoral joint space was concordant with the patient's reporting of improvement in stiffness and pain. The sustained pain relief and muscle relaxation enabled the patients to optimize physiotherapy thereby improving endurance training to include the daily activities of life. We conclude that OA knee pain is a product of neuromyopathy and that PRF of the sensory and motor nerves appeared to be a safe, effective, and minimally invasive technique. The reduction of pain and stiffness improved the knee function and probably reduced the peripheral and central sensitization.

Evaluation of postoperative pulmonary regurgitation after surgical repair of tetralogy of Fallot: comparison between Doppler echocardiography and MR velocity mapping

International Nuclear Information System (INIS)

Grothoff, Matthias; Spors, Birgit; Gutberlet, Matthias; Abdul-Khaliq, Hasim

2008-01-01

Pulmonary regurgitation is a common finding in patients after correction of tetralogy of Fallot (TOF). Right ventricular impairment and even ventricular arrhythmia have been ascribed to pulmonary valve insufficiency (PI), which is therefore an important issue in follow-up examinations. To compare PI measured by echocardiography (ECHO) with data provided by cardiac MRI (CMR). We studied 54 selected patients (18 female; median age 14.0 years, range 3.8-53.4 years) after surgical correction of TOF. To quantify pulmonary regurgitant fraction (PRF) by CMR, flow velocity mapping was performed. On Doppler ECHO, length, width and localization of regurgitant flow was measured. The severity of PI was categorized as mild, moderate or severe and compared to the data obtained by CMR. On CMR the mean PRF was 29.2 ± 13.4%. Patients with a transannular patch had a significantly higher PRF (39.9 ± 11.6%) than patients with an intact annular ring (23.6 ± 11.4%). Differentiation by Doppler ECHO between the categories mild, moderate and severe PI was confirmed by significant differences in PRF measured by CMR (mild vs. moderate P < 0.04; moderate vs. severe P < 0.014; mild vs. severe P < 0.001). Furthermore, PRF correlated with right ventricular end diastolic volume index (r = 0.45, P < 0.01) and right ventricular end systolic volume index (r = 0.39, P < 0.01). Doppler ECHO can estimate the severity of PI after repair of TOF with acceptable results compared to CMR flow measurement. In univariate analysis there is only a weak influence of PRF on right ventricular volume. (orig.)

Power Doppler signal calibration between ultrasound machines by use of a capillary-flow phantom for pannus vascularity in rheumatoid finger joints: a basic study.

Science.gov (United States)

Sakano, Ryosuke; Kamishima, Tamotsu; Nishida, Mutsumi; Horie, Tatsunori

2015-01-01

Ultrasound allows the detection and grading of inflammation in rheumatology. Despite these advantages of ultrasound in the management of rheumatoid patients, it is well known that there are significant machine-to-machine disagreements regarding signal quantification. In this study, we tried to calibrate the power Doppler (PD) signal of two models of ultrasound machines by using a capillary-flow phantom. After flow velocity analysis in the perfusion cartridge at various injection rates (0.1-0.5 ml/s), we measured the signal count in the perfusion cartridge at various injection rates and pulse repetition frequencies (PRFs) by using PD, perfusing an ultrasound micro-bubble contrast agent diluted with normal saline simulating human blood. By use of the data from two models of ultrasound machines, Aplio 500 (Toshiba) and Avius (Hitachi Aloka), the quantitative PD (QPD) index [the summation of the colored pixels in a 1 cm × 1 cm rectangular region of interest (ROI)] was calculated via Image J (internet free software). We found a positive correlation between the injection rate and the flow velocity. In Aplio 500 and Avius, we found negative correlations between the PRF and the QPD index when the flow velocity was constant, and a positive correlation between flow velocity and the QPD index at constant PRF. The equation for the relationship of the PRF between Aplio 500 and Avius was: y = 0.023x + 0.36 [y = PRF of Avius (kHz), x = PRF of Aplio 500 (kHz)]. Our results suggested that the signal calibration of various models of ultrasound machines is possible by adjustment of the PRF setting.

Effects of Plasma Rich in Growth Factors and Platelet-Rich Fibrin on Proliferation and Viability of Human Gingival Fibroblasts

Directory of Open Access Journals (Sweden)

Surena Vahabi

2016-01-01

Full Text Available Objectives: Platelet preparations are commonly used to enhance bone and soft tissue regeneration. Considering the existing controversies on the efficacy of platelet products for tissue regeneration, more in vitro studies are required. The aim of the present study was to compare the in vitro effects of plasma rich in growth factors (PRGF and platelet-rich fibrin (PRF on proliferation and viability of human gingival fibroblasts (HGFs.Materials and Methods: Anitua's PRGF and Choukran's PRF were prepared according to the standard protocols. After culture periods of 24, 48 and 72 hours, proliferation of HGFs was evaluated by the methyl thiazol tetrazolium assay. Statistical analysis was performed using one-way ANOVA followed by Tukey-Kramer’s multiple comparisons and P-values<0.05 were considered statistically significant.Results: PRGF treatment induced statistically significant (P<0.001 proliferation of HGF cells compared to the negative control (100% viability at 24, 48 and 72 hours in values of 123%±2.25%, 102%±2.8% and 101%±3.92%, respectively. The PRF membrane treatment of HGF cells had a statistically significant effect on cell proliferation (21%±1.73%, P<0.001 at 24 hours compared to the negative control. However, at 48 and 72 hours after treatment, PRF had a negative effect on HGF cell proliferation and caused 38% and 60% decrease in viability and proliferation compared to the negative control, respectively. The HGF cell proliferation was significantly higher in PRGF than in PRF group (P< 0.001.Conclusion: This study demonstrated that PRGF had a strong stimulatory effect on HGF cell viability and proliferation compared to PRF.

Cubic metaplectic forms and theta functions

CERN Document Server

Proskurin, Nikolai

1998-01-01

The book is an introduction to the theory of cubic metaplectic forms on the 3-dimensional hyperbolic space and the author's research on cubic metaplectic forms on special linear and symplectic groups of rank 2. The topics include: Kubota and Bass-Milnor-Serre homomorphisms, cubic metaplectic Eisenstein series, cubic theta functions, Whittaker functions. A special method is developed and applied to find Fourier coefficients of the Eisenstein series and cubic theta functions. The book is intended for readers, with beginning graduate-level background, interested in further research in the theory of metaplectic forms and in possible applications.

Conference L-Functions and Automorphic Forms

CERN Document Server

Kohnen, Winfried; LAF

2017-01-01

This book presents a collection of carefully refereed research articles and lecture notes stemming from the Conference "Automorphic Forms and L-Functions", held at the University of Heidelberg in 2016.  The theory of automorphic forms and their associated L-functions is one of the central research areas in modern number theory, linking number theory, arithmetic geometry, representation theory, and complex analysis in many profound ways.  The 19 papers cover a wide range of topics within the scope of the conference, including automorphic L-functions and their special values, p-adic modular forms, Eisenstein series, Borcherds products, automorphic periods, and many more.

Reflective Functioning, Physiological Reactivity, and Overcontrol in Mothers: Links with School-Aged Children's Reflective Functioning

Science.gov (United States)

Borelli, Jessica L.; Hong, Kajung; Rasmussen, Hannah F.; Smiley, Patricia A.

2017-01-01

Theorists argue that parental reflective functioning (PRF) is activated in response to emotions, potentially supporting parenting sensitivity even when arousal is high. That is, when parents become emotionally reactive when interacting with their children, those who can use PRF to understand their children's mental states should be able to parent…

Correlation between lumbar lordosis and the treatment of chronic low back pain with pulsed radiofrequency applied to the L2 dorsal root ganglion

Directory of Open Access Journals (Sweden)

Hsien-Ta Hsu

2017-01-01

Conclusion: PRF applied to the L2 DRG is an alternative procedure for treating patients with chronic low back pain, regardless of which type of LL the patients have. Chronic low back pain, including discogenic pain and facet joint pain, may be treated by PRF applied to the L2 DRG.

SAM2_AERO_PRF_NAT

Data.gov (United States)

National Aeronautics and Space Administration — Stratospheric Aerosol Measurement II - Aerosol Profile - Native format which measures solar irradiance attenuated by aerosol particles in the Arctic & Antarctic...

High PRF high current switch

Science.gov (United States)

Moran, Stuart L.; Hutcherson, R. Kenneth

1990-03-27

A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

Clinical effect of platelet rich fibrin in the treatment of periodontal intrabony defects. Systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Heber Arbildo.

2017-05-01

Full Text Available Background: There is currently no gold standard biomaterial for the treatment of periodontal intrabony defects (PIDs. One of the current options is the use of platelet-rich fibrin (PRF. Objective: To determine the clinical effect of PRF in the treatment of PID through a systematic review and meta-analysis. Materials and Methods: A literature search was conducted up to February 2017 in the following biomedical databases: Pubmed, Embase, Scielo, Science Direct, SIGLE, LILACS and in the Cochrane Central Register of Clinical Trials. The selection criteria included: randomized clinical trials published in the last 5 years, reporting clinical effects (probing depth, clinical insertion level or gingival recession, with a follow-up time equal to or greater than 6 months, and sample size larger than or equal to 10 patients reporting the use of PRF as a treatment for PID. The methodological quality of the studies was analyzed using the Cochrane Handbook of Systematic Reviews of Interventions as a reference. Results: The search strategy yielded 20 articles. A reduction in probing depth and an increase in clinical insertion level or a reduction in gingival recession is reported, when using PRF alone or in combination with another biomaterial or substance that stimulates tissue regeneration. Conclusion: The literature suggests that the use of PRF in the treatment of PIDs has a beneficial clinical effect when compared to control treatments.

Does temperature nudging overwhelm aerosol radiative ...

Science.gov (United States)

For over two decades, data assimilation (popularly known as nudging) methods have been used for improving regional weather and climate simulations by reducing model biases in meteorological parameters and processes. Similar practice is also popular in many regional integrated meteorology-air quality models that include aerosol direct and indirect effects. However in such multi-modeling systems, temperature changes due to nudging can compete with temperature changes induced by radiatively active & hygroscopic short-lived tracers leading to interesting dilemmas: From weather and climate prediction’s (retrospective or future) point of view when nudging is continuously applied, is there any real added benefit of using such complex and computationally expensive regional integrated modeling systems? What are the relative sizes of these two competing forces? To address these intriguing questions, we convert temperature changes due to nudging into radiative fluxes (referred to as the pseudo radiative forcing, PRF) at the surface and troposphere, and compare the net PRF with the reported aerosol radiative forcing. Results indicate that the PRF at surface dominates PRF at top of the atmosphere (i.e., the net). Also, the net PRF is about 2-4 times larger than estimated aerosol radiative forcing at regional scales while it is significantly larger at local scales. These results also show large surface forcing errors at many polluted urban sites. Thus, operational c

Potential Effect of Leukocyte-Platelet-Rich Fibrin in Bone Healing of Skull Base: A Pilot Study

Directory of Open Access Journals (Sweden)

Felipe Fredes

2017-01-01

Full Text Available Background. Reconstruction of surgical defects following cranial base surgery is challenging. Others have demonstrated that leukocyte-platelet-rich fibrin (L-PRF stimulates tissue healing and bone regeneration. However, these studies have addressed mostly maxillofacial surgical wounds. Objective. The objective of this study was to assess the possible adjuvant role of L-PRF in inducing neoossification of the surgical bone defect in anterior skull base surgery. Methods. We identified patients who had undergone an endoscopic endonasal surgery of the anterior skull base in which L-PRF membranes were used for the reconstruction of the bone defect and who were followed up with postoperative CT scans. CT findings were then correlated with baseline scans and with the CT scans of a patient who had undergone imaging and histologic analysis after maxillofacial surgery in which L-PRF was used and in which we demonstrated bone formation. Results. Five patients fulfilled the inclusion criteria. In four patients, the CT scan demonstrated closure of the bony defect by neoosteogenesis; however, the bone appeared less dense than the surrounding normal bone. A comparison with the control patient yielded similar radiological features. Conclusion. This case series suggests that L-PRF may induce bone healing and regeneration at the surgical site defect. Multi-institutional studies with a larger series of patients are required to confirm this possibility.

Imulation of polymer forming processes - addressing industrial needs

International Nuclear Information System (INIS)

Thibault, F.; DiRaddo, R.

2011-01-01

The objective of this paper is to present the development of simulation and design optimization capabilities, for polymer forming processes, in the context of addressing industrial needs. Accomplishments generated from close to twenty years of research in this field, at the National Research Council (NRC), are presented. Polymer forming processes such as extrusion blow moulding, stretch blow moulding and thermoforming have been the focus of the work, yet the research is extendable to similar polymer forming operations such as micro-blow moulding, sheet blow moulding and composites stamping. The research considers material models, process sequence integration and design optimization, derivative processes and 3D finite elements with multi-body contact.

Simulation of root forms using cellular automata model

International Nuclear Information System (INIS)

Winarno, Nanang; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

2016-01-01

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations

Simulation of root forms using cellular automata model

Energy Technology Data Exchange (ETDEWEB)

Winarno, Nanang, E-mail: nanang-winarno@upi.edu; Prima, Eka Cahya [International Program on Science Education, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi no 229, Bandung40154 (Indonesia); Afifah, Ratih Mega Ayu [Department of Physics Education, Post Graduate School, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi no 229, Bandung40154 (Indonesia)

2016-02-08

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.

Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

KAUST Repository

Bhavani Shankar, Vijai Shankar

2016-04-05

Primary Reference Fuels (PRFs) - binary mixtures of n-heptane and iso-octane based on Research Octane Number (RON) - are popular gasoline surrogates for modeling combustion in spark ignition engines. The use of these two component surrogates to represent real gasoline fuels for simulations of HCCI/PCCI engines needs further consideration, as the mode of combustion is very different in these engines (i.e. the combustion process is mainly controlled by the reactivity of the fuel). This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

The general transcriptional repressor Tup1 is required for dimorphism and virulence in a fungal plant pathogen.

Directory of Open Access Journals (Sweden)

Alberto Elías-Villalobos

2011-09-01

Full Text Available A critical step in the life cycle of many fungal pathogens is the transition between yeast-like growth and the formation of filamentous structures, a process known as dimorphism. This morphological shift, typically triggered by multiple environmental signals, is tightly controlled by complex genetic pathways to ensure successful pathogenic development. In animal pathogenic fungi, one of the best known regulators of dimorphism is the general transcriptional repressor, Tup1. However, the role of Tup1 in fungal dimorphism is completely unknown in plant pathogens. Here we show that Tup1 plays a key role in orchestrating the yeast to hypha transition in the maize pathogen Ustilago maydis. Deletion of the tup1 gene causes a drastic reduction in the mating and filamentation capacity of the fungus, in turn leading to a reduced virulence phenotype. In U. maydis, these processes are controlled by the a and b mating-type loci, whose expression depends on the Prf1 transcription factor. Interestingly, Δtup1 strains show a critical reduction in the expression of prf1 and that of Prf1 target genes at both loci. Moreover, we observed that Tup1 appears to regulate Prf1 activity by controlling the expression of the prf1 transcriptional activators, rop1 and hap2. Additionally, we describe a putative novel prf1 repressor, named Pac2, which seems to be an important target of Tup1 in the control of dimorphism and virulence. Furthermore, we show that Tup1 is required for full pathogenic development since tup1 deletion mutants are unable to complete the sexual cycle. Our findings establish Tup1 as a key factor coordinating dimorphism in the phytopathogen U. maydis and support a conserved role for Tup1 in the control of hypha-specific genes among animal and plant fungal pathogens.

Comparative evaluation of coronally advanced flap using amniotic membrane and platelet-rich fibrin membrane in gingival recession: An 18-month clinical study

Directory of Open Access Journals (Sweden)

Mohd Rehan

2018-01-01

Full Text Available Background: An amnion membrane is a placenta-derived tissue that consists of numerous growth factors, proteins, and stem cell reserves which help in accelerated wound healing and regeneration. Platelet-rich fibrin (PRF also releases growth factors after activation from the platelets and gets trapped within fibrin matrix which has been shown to stimulate the mitogenic response in the periosteum for bone repair and regeneration during normal wound healing. This preliminary, controlled, randomized clinical trial with an 18-month follow-up was aimed to evaluate the effectiveness of coronally advanced flap (CAF with either PRF membrane or bioresorbable amniotic membrane (AM in treatment of localized gingival recession defects. Materials and Methods: Sixteen healthy adult patients presenting with Miller Class I recession defects were treated surgically with CAF along with AM (Group I or PRF (Group II for coverage of the recession defects. For all patients, plaque index, gingival index, bleeding on probing, clinical attachment level, depth of recession, width of recession, width of attached gingiva, and gingival thickness were evaluated at 6 months and 18 months postoperatively. Statistical analysis was done using paired t-test, repeated measure analysis of variance test, Bonferroni test for intragroup comparison and unpaired t-test for intergroup comparison. Results: The results showed statistically nonsignificant (P < 0.01 difference in all clinical parameters at the 6- and 18-month follow-ups in both groups. Gingival recession in both PRF and amnion group when evaluated individually, significantly reduced from baseline to 6 months (P = 0.000 and from baseline to 18 months (P = 0.000. However, the mean value from 6 months to 18 months was statistically nonsignificant. Conclusion: The present study demonstrated that both CAF + PRF and CAF + AM are equally effective in providing clinically significant outcomes with respect to root coverage with AM

Effect of centrifugation time on growth factor and MMP release of an experimental platelet-rich fibrin-type product.

Science.gov (United States)

Eren, Gülnihal; Gürkan, Ali; Atmaca, Harika; Dönmez, Ayhan; Atilla, Gül

2016-07-01

Platelet-rich fibrin (PRF) has a controlled release of growth factors due to the fibrin matrix structure. Different centrifugation protocols were suggested for PRF preparation. Since the derivation method of PRF can alter its contents, in the present study it is aimed to investigate the cell contents and transforming growth factor beta-1 (TGF-β1), platelet-derived growth factor (PDGF-AB), vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-1 and-8 release from experimental PRF-type membranes obtained with different centrifugation times at 400 gravity. Three blood samples were collected from 20 healthy non-smoker volunteers. One tube was used for whole blood analyses. The other two tubes were centrifuged at 400 g for 10 minutes (group A) or 12 minutes (group B). Each experimental PRF-type membrane was placed in Dulbecco's Modified Eagle's Medium (DMEM)and at 1, 24 and 72 hours, TGF-β1, PDGF-AB, VEGF, MMP-1 and -8 release amounts were analysed by enzyme-linked immunosorbent assay (ELISA). The blood cell count of membranes was determined by subtracting plasma supernatant and red blood cell (RBC) mixture from the whole blood cell counts. At 72 hours, the VEGF level of group B was statistically higher than that of group A (p = 0.040). The centrifugation time was not found to influence the release of other growth factors, enzymes and cell counts. Within the limits of the present study, it might be suggested that centrifugation time at a constant gravity has a significant effect on the VEGF levels released from experimental PRF-type membrane. It can be concluded that due to the importance of VEGF in the tissue healing process, membranes obtained at 12-minute centrifugation time may show a superior potential in wound healing.

Second-generation Platelet Concentrate (Platelet-rich Fibrin) as a Scaffold in Regenerative Endodontics: A Case Series.

Science.gov (United States)

Bakhtiar, Hengameh; Esmaeili, Shahram; Fakhr Tabatabayi, Setareh; Ellini, Mohammad Reza; Nekoofar, Mohammad Hossein; Dummer, Paul M H

2017-03-01

The purpose of this case series was to report the clinical and radiographic results of a pulp regenerative procedure using platelet-rich fibrin (PRF), a second-generation platelet concentrate, in immature teeth with necrotic pulps. Root canal revascularization using PRF was performed on 4 immature teeth with necrotic pulps. After access cavity preparation, the root canals were irrigated with low concentration sodium hypochlorite solution (1.5% sodium hypochlorite [20 mL/canal, 5 minutes]) and then irrigated with saline (20 mL/canal, 5 minutes). Equal proportions (167 mg) of ciprofloxacin, metronidazole, and cefaclor were mixed and diluted to a final concentration of 1 g/mL. Finally, the canal was sealed with 3-4 mm of a temporary restorative material, and patients were dismissed for 2 to 3 weeks. At the second appointment, 9 mL of the patient's whole blood was obtained and centrifuged to prepare a PRF clot. Canals were irrigated with 17% EDTA, and a sharp spreader was inserted beyond the apex. Then, the PRF clot was placed inside the root canals, and Biodentine (Septodont, Saint-Maur, France) was placed directly over the PRF. The teeth were restored permanently with glass ionomer cement and composite resin. Clinical examinations revealed that all cases were asymptomatic at the recall appointments at 1, 3, 6, 12, and 18 months. Radiographs revealed resolution of the periapical lesions, further root development, and apical closure in all cases. On the basis of the short-term results up to 12 months, PRF clots acted as successful scaffolds for the regeneration of pulpal contents in immature teeth with necrotic pulps. Copyright © 2016 American Association of Endodontists. All rights reserved.

Sheet-bulk metal forming – forming of functional components from sheet metals

Directory of Open Access Journals (Sweden)

Merklein Marion

2015-01-01

Full Text Available The paper gives an overview on the application of sheet-bulk metal forming operations in both scientific and industrial environment. Beginning with the need for an innovative forming technology, the definition of this new process class is introduced. The rising challenges of the application of bulk metal forming operations on sheet metals are presented and the demand on a holistic investigation of this topic is motivated. With the help of examples from established production processes, the latest state of technology and the lack on fundamental knowledge is shown. Furthermore, perspectives regarding new research topics within sheet-bulk metal forming are presented. These focus on processing strategies to improve the quality of functional components by the application of process-adapted semi-finished products as well as the local adaption of the tribological system.

Circle of Form

DEFF Research Database (Denmark)

Jaeger, Thomas Arvid

2012-01-01

a common professional language like in mathematics, colour and music. The result is a weaker professionalism in the aesthetic competences compared to the professionalism and competences in other areas. A research project [1] on contrasts or opposites in form investigated the phenomenon in the fields...

Research on the Bionics Design of Automobile Styling Based on the Form Gene

Science.gov (United States)

Aili, Zhao; Long, Jiang

2017-09-01

From the heritage of form gene point of view, this thesis has analyzed the gene make-up, cultural inheritance and aesthetic features in the evolution and development of forms of brand automobiles and proposed the bionic design concept and methods in the automobile styling design. And this innovative method must be based on the form gene, and the consistency and combination of form element must be maintained during the design. Taking the design of Maserati as an example, the thesis will show you the design method and philosophy in the aspects of form gene expression and bionic design innovation for the future automobile styling.

A comparative study of the oxidation characteristics of two gasoline fuels and an n-heptane/iso-octane surrogate mixture

KAUST Repository

Javed, Tamour

2015-01-01

Ignition delay times and CO, H2O, OH and CO2 time-histories were measured behind reflected shock waves for two FACE (Fuels for Advanced Combustion Engines) gasolines and one PRF (Primary Reference Fuel) blend. The FACE gasolines chosen for this work are primarily paraffinic and have the same octane rating (∼RON = 84) as the PRF blend, but contain varying amounts of iso- and n-paraffins. Species time-histories and ignition delay times were measured using laser absorption methods over a temperature range of 1350-1550 K and pressures near 2 atm. Measured species time-histories and ignition delay times of the PRF blend and the two FACE fuels agreed reasonably well. However, when compared to recent gasoline surrogate mechanisms, the simulations did not capture some of the kinetic trends found in the species profiles. To our knowledge, this work provides some of the first shock tube species time-history data for gasoline fuels and PRF surrogates and should enable further improvements in detailed kinetic mechanisms of gasoline fuels.

Maximizing Entropy of Pickard Random Fields for 2x2 Binary Constraints

DEFF Research Database (Denmark)

Søgaard, Jacob; Forchhammer, Søren

2014-01-01

This paper considers the problem of maximizing the entropy of two-dimensional (2D) Pickard Random Fields (PRF) subject to constraints. We consider binary Pickard Random Fields, which provides a 2D causal finite context model and use it to define stationary probabilities for 2x2 squares, thus...... allowing us to calculate the entropy of the field. All possible binary 2x2 constraints are considered and all constraints are categorized into groups according to their properties. For constraints which can be modeled by a PRF approach and with positive entropy, we characterize and provide statistics...... of the maximum PRF entropy. As examples, we consider the well known hard square constraint along with a few other constraints....

Redox Biology Course Evaluation Form | Center for Cancer Research

Science.gov (United States)

To improve the Redox Biology (RB) course in future years, we would appreciate your feedback by completing this course evaluation. Please score the course elements as poor, fair, average, good or excellent. Please type any comments that you have in response to the questions at the bottom of the form. Remember to include your name as you wish it to appear on the certificate.

Influence of university network structures on forming the network environment of regional economy (on the example of national research universities of Tatarstan Republic

Directory of Open Access Journals (Sweden)

Darya-Anna Alekseevna Kaibiyainen

2015-03-01

Full Text Available Objective to elaborate theoretical and applied aspects of the processes of forming the new network institutional environment of the Russian regional economy under the influence of the developing integral educational network structures basing on the study of the experience of national research universities of Tatarstan Republic Methods general scientific logical methods of analysis and synthesis induction and deduction scientific abstraction as well as the method of systemicfunctional analysis. Results the practical examples are revealed and analyzed of introducing the new network integral principles into the functioning of national research universities which have a real economic effect and influencing such indicators of regional economy as the growth of employment reduction of unemployment etc. Scientific novelty problems of network structures development in the Russian education have not been thoroughly studied yet. The article analyzes the experience reveals and describes the methods and techniques of forming the network educational structures in the functioning of national research universities in Tatarstan Republic Practical value the author shows the ability of network university structures not only to play a significant role forming the new institutional environment of the regional economy but also to influence the macro and microeconomic indicators of development of the region and the country. nbsp

Redox Biology Course Evaluation Form | Center for Cancer Research

Science.gov (United States)

To improve the Redox Biology (RB) course in future years, we would appreciate your feedback by completing this course evaluation. Please score the course elements as poor, fair, average, good or excellent. Please type any comments that you have in response to the questions at the bottom of the form. Remember to include your name as you wish it to appear on the certificate. Thank you for your feedback.

Role of pH Changes on Transforming Growth Factor-β1 Release and on the Fibrin Architecture of Platelet-rich Fibrin When Layered with Biodentine, Glass Ionomer Cement, and Intermediate Restorative Material.

Science.gov (United States)

Mullaguri, Harish; Suresh, Nandini; Surendran, Smitha; Velmurugan, Natanasabapathy; Chitra, Selvarajan

2016-05-01

The purpose of this study was to evaluate the influence of pH that is due to setting reaction of Biodentine, glass ionomer cement (GIC), and intermediate restorative material (IRM) on transforming growth factor-β1 (TGF-β1) release and on the fibrin architecture of platelet-rich fibrin (PRF). PRF was obtained from 8 volunteers and layered over the freshly prepared GIC, IRM, and Biodentine mixtures. TGF-β1 release was estimated by using enzyme-linked immunosorbent assay (ELISA), and fibrin structure of PRF was analyzed by using scanning electron microscope at 1 and 5 hours. Biodentine, GIC, and IRM increased the TGF-β1 release in comparison with that of control group (PRF alone) at both 1 and 5 hours. Biodentine released significantly more TGF-β1 than GIC and IRM at 1 hour. At 5 hours both GIC and Biodentine released significantly more TGF-β1 than IRM. The fibrin architecture of the Biodentine group was similar to that of control group at both 1 and 5 hours. In GIC and IRM groups the fibrillar structure of fibrin was collapsed, ill-defined, and cloudy with very thick fibers and irregularly reduced porosities. Biodentine induces larger amount of TGF-β1 release and also maintains the integrity of fibrin structure when compared with GIC and IRM when layered over PRF. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Fructification of Langermannia gigantea in artificially inoculated field soil

Czech Academy of Sciences Publication Activity Database

Gryndler, M.; Borovička, Jan; Gryndlerová, H.; Gryndler, E.

2008-01-01

Roč. 60, č. 2 (2008), s. 231-242 ISSN 1211-0981 Grant - others:Grant Agency of the Charles University, Prague(CZ) GAUK 247/2006/B-GEO/Prf Institutional research plan: CEZ:AV0Z30130516 Keywords : Lycoperdaceae, * Langermannia gigantea * Calvatia gigantea * spawn * cultivation * rDNA Subject RIV: DB - Geology ; Mineralogy http://prfdec.natur.cuni.cz/cvsm/CM60207.pdf

International Recognition of FormAkademisk

Directory of Open Access Journals (Sweden)

Janne Beate Reitan

2017-12-01

Full Text Available FormAkademisk was invited to the Design Journal Editors' Meeting at the College of Design, Architecture, Art, and Planning (DAAP, University of Cincinnati in late October, as the only design research journal from the Nordic region. The meeting was organized in advance of the International Association of Societies of Design Research (IASDR 2017 conference.Liv Merete Nielsen, who initiated the creation of  FormAkademisk and has been a Section Editor since the start-up and I, who have been the Editor-in-Chief for the entire period, travelled to the meeting.FormAkademisk   was in good company - among the others invited, we can mention the American Design Issues and the British Design Studies, both of which are at Level 2 of the Norwegian Science Index - NVI. Other reputable journals invited were the International Journal of Design from Taiwan, She Ji - The Journal of Design, Economics, and Innovation from Tongji University in Shanghai, China, Design and Culture from the United States, Co-Design from the United Kingdom, Information Design Journal published in the Netherlands with an international editorial board, Journal of Design, Business & Society with an international editorial board, the French Sciences du Design and Visible Language published at the University of Cincinnati, USA who hosted the meeting.First, we warmed up by describing each journal's editorial profile. For FormAkademisk we emphasized that we have two equal focuses – research in design, but also research in design education for the general public. This combination seems to be unique internationally.Common issues we discussed further were challenges with the quality of submitted articles and obtaining qualified peer reviewers. We also discussed whether we would agree on a common understanding of what it means to be included as an author of an article. Based on the discussions, FormAkademisk comes well prepared compared to the other internationally leading design research

Editorial -Research! Research! Research! What are Thou?

Directory of Open Access Journals (Sweden)

Ashok Shyam

2013-04-01

Full Text Available Being in field of Orthopaedic research since last 6 years, I have personally been witness to the rapid change in landscape of Othopaedic Research and also medical research in general. The sheer volumes of publications is overwhelming to the extent of being mostly ineffective in providing significant positive addition to the current literature. “There are too many variables” is one of my favorite phrase when I start to explain something to myself. Looking at as many variables as we can think of, makes us understand concepts within the limitations of given variables. Something similar to Ashby’s law that we spoke about in last Editorial [1]. However when we try to apply this to word ‘Research’ the amount of subjective stereotype that is associated with the word defeats all attempt to decipher and communicate clearly. Originally word Research derived from French ‘Researche’ simply means ‘Pursuit of Knowledge’. We as medical practitioners in search of better treatment for our patients are always in pursuit of knowledge. This knowledge is mostly build individually and is learned from individual experience and learning. This is a subjective body of knowledge and this is what makes one surgeon better than another. But is this ‘Research’? Yes it is Research and it serves the main purpose of medical research that is to improve the treatment given to patients. However this is a limited form of research, limited by individual’s ability and capacity. It also does not subject itself to rigorous ‘scientific methods’ and may not be acceptable to a community of ‘Modern Researchers’. Another form of Research of pursuit of knowledge is again from the clinics and from reading journals and books. A collaboration of clinical experience and written word adds a more thoughtful way of pursuing knowledge. This I think is the way majority of medical practitioners acquire knowledge. This keeps them updated and also helps them provide good

Research on Liquid Forming Process of Nickel Superalloys Thin Sheet Metals

Directory of Open Access Journals (Sweden)

Hyrcza-Michalska M.

2017-12-01

Full Text Available The paper presents the study of drawability of thin sheet metals made of a nickel superalloy Inconel type. The manufacturing process of axisymmetric cup – cone and a closed section profile in the form of a circular tube were designed and analyzed. In both cases, working fluid-oil was used in place of the rigid tools. The process of forming liquid is currently the only alternative method for obtaining complex shapes, coatings, and especially if we do it with high-strength materials. In the case of nickel superalloys the search for efficient methods to manufacture of the shaped shell is one of the most considerable problems in aircraft industry [1-5]. However, the automotive industries have the same problem with so-called advanced high-strength steels (AHSS. Due to this, both industrial problems have been examined and the emphasis have been put on the process of liquid forming (hydroforming. The study includes physical tests and the corresponding numerical simulations performed, using the software Eta/Dynaform 5.9. Numerical analysis of the qualitative and quantitative forecasting enables the formability of materials with complex and unusual characteristics of the mechanical properties and forming technology. It has been found that only the computer aided design based on physical and numerical modeling, makes efficient plastic processing possible using a method of hydroforming. Drawability evaluation based on the determination of the mechanical properties of complex characteristics is an indispensable element of this design in the best practice of industrial manufacturing products made of thin sheet metals.

Review of David Abrahamson and Marcia R. Prior-Miller (eds, The Routledge Handbook of Magazine Research: The Future of the Magazine Form (2015

Directory of Open Access Journals (Sweden)

Maaike Koffeman

2016-07-01

Full Text Available David Abrahamson and Marcia R. Prior-Miller (eds, The Routledge Handbook of Magazine Research: The Future of the Magazine Form (New York: Routledge, 2015. 650 pp. ISBN 978-1138854161.

Platelet-rich fibrin versus albumin in surgical wound repair: a randomized trial with paired design

DEFF Research Database (Denmark)

Danielsen, Patricia L; Ågren, Sven Per Magnus; Jørgensen, Lars Nannestad

2010-01-01

To study the effects of autologous platelet-rich fibrin (PRF) versus human albumin on incisional wound breaking strength and subcutaneous collagen deposition in patients undergoing laparoscopic cholecystectomy in a randomized trial.......To study the effects of autologous platelet-rich fibrin (PRF) versus human albumin on incisional wound breaking strength and subcutaneous collagen deposition in patients undergoing laparoscopic cholecystectomy in a randomized trial....

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial.

Science.gov (United States)

Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K

2015-09-29

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in surgeries because of its superior handling characteristics as well as its suturability to the wound bed. The goal of the study is to demonstrate generation as well as provide detailed characterization of relevant properties of L-PRF that underlie its clinical success.

THE PRENATAL PARENTAL REFLECTIVE FUNCTIONING QUESTIONNAIRE: EXPLORING FACTOR STRUCTURE AND CONSTRUCT VALIDITY OF A NEW MEASURE IN THE FINN BRAIN BIRTH COHORT PILOT STUDY.

Science.gov (United States)

Pajulo, Marjukka; Tolvanen, Mimmi; Karlsson, Linnea; Halme-Chowdhury, Elina; Öst, Camilla; Luyten, Patrick; Mayes, Linda; Karlsson, Hasse

2015-01-01

Parental reflective functioning (PRF) is the capacity to focus on experience and feelings in oneself and in the child. Individual differences in PRF reportedly affect child attachment and socioemotional development. In this study, we report work on developing a questionnaire to assess PRF during pregnancy (Prenatal Parental Reflective Functioning Questionnaire; P-PRFQ). The factor structure of the 33-item version of the P-PRFQ was explored using pilot study data from the Finn Brain Birth Cohort Study (n = 124 mothers, n = 82 fathers). Construct validity was assessed against the Pregnancy Interview (PI; A. Slade, L. Grunebaum, L. Huganir, & M. Reeves, 1987, 2002, 2011) in a subsample of 29 mothers from the same pilot sample. Exploratory and confirmatory factor analysis resulted in a 14-item P-PRFQ, with three factors which seem to capture relevant aspects of prenatal parental mentalization-F1: "Opacity of mental states," F2: "Reflecting on the fetus-child," and F3: "The dynamic nature of the mental states." Functioning of the factor structure was further tested in the large cohort with 600 mothers and 600 fathers. Correlations with the PI result were high, both regarding total and factor scores of the P-PRFQ. Cost-effective tools to assess key areas of early parenting are needed for both research and clinical purposes. The 14-item P-PRFQ seems to be an applicable and promising new tool for assessing very early parental mentalizing capacity. © 2015 Michigan Association for Infant Mental Health.

Writing a Research Proposal to The Research Council of Oman

OpenAIRE

Al-Shukaili, Ahmed; Al-Maniri, Abdullah

2017-01-01

Writing a research proposal can be a challenging task for young researchers. This article explains how to write a strong research proposal to apply for funding, specifically, a proposal for The Research Council (TRC) of Oman. Three different research proposal application forms are currently used in TRC, including Open Research Grant (ORG), Graduate Research Support Program (GRSP), and Faculty-mentored Undergraduate Research Award Program (FURAP). The application forms are filled and submitted...

Research on making reactor buildings of irregular plan and elevation forms aseismatic

International Nuclear Information System (INIS)

Okawa, Izuru; Yamauchi, Yasuyuki

1997-01-01

The necessity of pursuing the possibility of irregular form buildings as the condition of location for construction is limited, and the rational and economical arrangement of equipment and piping is considered. In order to know the effect that irregular forms exert to the aseismatic ability of buildings, it is indispensable to develop the program for precision three-dimensional elastoplastic analysis at the time of earthquakes. As the means of solving the problem, the introduction of seismic insulation structure is conceivable. The investigation of seismic insulator and its modeling and the analysis of earthquake response were carried out, and the irregular form and the effect of seismic insulation were investigated, and the results of vibration test using test specimens were summarized. The concrete items of investigation were the characteristics of input earthquake motion, the techniques of analysis, the parametric study taking the input and various characteristics of buildings in consideration, and the synthetic assessment. The vibration table experiment and the static loading experiment for the purpose of grasping the response behavior in the case of irregular form of wall type and seismic insulation type structures were carried out, and the results are reported. (K.I.)

Platelet-Rich Fibrin Improves the Viability of Diced Cartilage Grafts in a Rabbit Model.

Science.gov (United States)

Göral, Ali; Aslan, Cem; Bolat Küçükzeybek, Betül; Işık, Dağhan; Hoşnuter, Mübin; Durgun, Mustafa

2016-04-01

Diced cartilage may be wrapped with synthetic or biological materials before grafting to a recipient site. These materials have unique advantages and disadvantages, and a gold standard is not available. The authors investigated the effects of platelet-rich fibrin (PRF) on the survival of cartilage grafts in a rabbit model. In this experimental study, diced cartilage pieces from the ears of 9 male rabbits were left unwrapped or were wrapped with PRF, oxidized regenerated cellulose, or fascia. Specimens then were placed into subcutaneous pockets prepared on the backs of the rabbits. The animals were sacrificed 2 months after the procedure, and the grafts were excised for macroscopic and histopathologic examination. The cartilage graft wrapped with PRF showed superior viability compared with the cartilage graft wrapped with oxidized regenerated cellulose. No significant differences were found among the other groups. The groups were not significantly different in terms of rates of inflammation, fibrosis, or vascularization. PRF enhances the viability of diced cartilage grafts and should be considered an appropriate biological wrapping material for cartilage grafting. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Ginsenoside Rg1 and platelet-rich fibrin enhance human breast adipose-derived stem cells function for soft tissue regeneration

Science.gov (United States)

Li, Hong-Mian; Peng, Qi-Liu; Huang, Min-Hong; Li, De-Quan; Liang, Yi-Dan; Chi, Gang-Yi; Li, De-Hui; Yu, Bing-Chao; Huang, Ji-Rong

2016-01-01

Adipose-derived stem cells (ASCs) can be used to repair soft tissue defects, wounds, burns, and scars and to regenerate various damaged tissues. The cell differentiation capacity of ASCs is crucial for engineered adipose tissue regeneration in reconstructive and plastic surgery. We previously reported that ginsenoside Rg1 (G-Rg1 or Rg1) promotes proliferation and differentiation of ASCs in vitro and in vivio. Here we show that both G-Rg1 and platelet-rich fibrin (PRF) improve the proliferation, differentiation, and soft tissue regeneration capacity of human breast adipose-derived stem cells (HBASCs) on collagen type I sponge scaffolds in vitro and in vivo. Three months after transplantation, tissue wet weight, adipocyte number, intracellular lipid, microvessel density, and gene and protein expression of VEGF, HIF-1α, and PPARγ were higher in both G-Rg1- and PRF-treated HBASCs than in control grafts. More extensive new adipose tissue formation was evident after treatment with G-Rg1 or PRF. In summary, G-Rg1 and/or PRF co-administration improves the function of HBASCs for soft tissue regeneration engineering. PMID:27191987

Review of high-level waste form properties

International Nuclear Information System (INIS)

Rusin, J.M.

1980-12-01

This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several additional waste forms have enough promise to warrant continued research and development to bring their state of development up to that of glass and calcine. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer potential advantages and need further study. Although this report discusses waste form properties, the total waste management system should be considered in the final selection of a waste form option. Canister design, canister materials, overpacks, engineered barriers, and repository characteristics, as well as the waste form, affect the overall performance of a waste management system. These parameters were not considered in this comparison

Acid-deposition research program. Volume 2. Effects of acid-forming emissions on soil microorganisms and microbially-mediated processes

Energy Technology Data Exchange (ETDEWEB)

Visser, S.; Danielson, R.M.; Parr, J.F.

1987-02-01

The interactions of soil physical, chemical, and biological processes are ultimately expressed in a soil's fertility and its capacity for plant production. Consequently, much of the research conducted to date regarding the impact of acid-forming pollutants on soil properties has been geared towards possible effects on plant productivity. This trend continues in this paper where the effects of acidic deposition on microbial communities are reviewed in relation to potential impact on plant growth. The objectives of the review are to discuss: (1) The effects of acid-forming emissions (primarily S-containing pollutants) on microbial community structure with emphasis on qualitative and quantitative aspects; (2) The effects of acidic deposition on microbially mediated processes (i.e., community functions); (3) Acidification effects of pollutants on symbiotic and disease-causing microorganisms. The symbionts discussed include ectomycorrhizal fungi, vesicular-arbuscular mycorrhizal fungi, and N/sub 2/-fixing bacteria, particularly Rhizobium, while the disease-causing microorganisms will include those responsible for foliage, stem, and root diseases.

Effect of osteogenic periosteal distraction by a modified Hyrax device with and without platelet-rich fibrin on bone formation in a rabbit model: a pilot study.

Science.gov (United States)

Pripatnanont, P; Balabid, F; Pongpanich, S; Vongvatcharanon, S

2015-05-01

This study evaluated the effect of a modified Hyrax device and platelet-rich fibrin (PRF) on osteogenic periosteal distraction (OPD). Twelve adult male New Zealand white rabbits were separated into two main groups (six in each) according to the duration of the consolidation period (4 or 8 weeks). In each main group, the animals underwent OPD of the left and right sides of the mandible and were divided into four subgroups (three animals per group): device vs. device+PRF, and PRF vs. sham. Radiographic, histological, histomorphometric, and micro-computed tomography (micro-CT) analyses were performed. New bone formation was observed on the lateral and vertical sides of the mandible of all groups. Micro-CT and histomorphometry showed that the device+PRF group presented the highest percentages of bone volume and bone area at 4 weeks (56.67 ± 12.67%, 41.37 ± 7.57%) and at 8 weeks (49.67 ± 8.33%, 55.46 ± 10.67%; significantly higher than the other groups, P<0.001), followed by the device group at 4 weeks (33.00 ± 1.73%, 33.21 ± 11.00%) and at 8 weeks (30.00 ± 3.00%, 23.25 ± 5.46%). In conclusion, the modified Hyrax device was used successfully for OPD in a rabbit model to gain vertical ridge augmentation, and greater bone maturation was achieved with the addition of PRF. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Combination of Mineral Trioxide Aggregate and Platelet-rich Fibrin Promotes the Odontoblastic Differentiation and Mineralization of Human Dental Pulp Cells via BMP/Smad Signaling Pathway.

Science.gov (United States)

Woo, Su-Mi; Kim, Won-Jae; Lim, Hae-Soon; Choi, Nam-Ki; Kim, Sun-Hun; Kim, Seon-Mi; Jung, Ji-Yeon

2016-01-01

Recent reports have shown that the combined use of platelet-rich fibrin (PRF), an autologous fibrin matrix, and mineral trioxide aggregate (MTA) as root filling material is beneficial for the endodontic management of an open apex. However, the potential of the combination of MTA and PRF as an odontogenic inducer in human dental pulp cells (HDPCs) in vitro has not yet been studied. The purpose of this study was to evaluate the effect of the combination of MTA and PRF on odontoblastic maturation in HDPCs. HDPCs extracted from third molars were directly cultured with MTA and PRF extract (PRFe). Odontoblastic differentiation of HDPCs was evaluated by measuring the alkaline phosphatase (ALP) activity, and the expression of odontogenesis-related genes was detected using reverse-transcription polymerase chain reaction or Western blot. Mineralization formation was assessed by alizarin red staining. HDPCs treated with MTA and PRFe significantly up-regulated the expression of dentin sialoprotein and dentin matrix protein-1 and enhanced ALP activity and mineralization compared with those with MTA or PRFe treatment alone. In addition, the combination of MTA and PRFe induced the activation of bone morphogenic proteins (BMP)/Smad, whereas LDN193189, the bone morphogenic protein inhibitor, attenuated dentin sialophosphoprotein and dentin matrix protein-1 expression, ALP activity, and mineralization enhanced by MTA and PRFe treatment. This study shows that the combination of MTA and PRF has a synergistic effect on the stimulation of odontoblastic differentiation of HDPCs via the modulation of the BMP/Smad signaling pathway. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Improvement in the repair of defects in maxillofacial soft tissue in irradiated minipigs by a mixture of adipose-derived stem cells and platelet-rich fibrin.

Science.gov (United States)

Chen, Yuanzheng; Niu, Zhanguo; Xue, Yan; Yuan, Fukang; Fu, Yanjie; Bai, Nan

2014-10-01

To find out if adipose-derived stem cells (ASC) and platelet-rich fibrin (PRF), alone or combined, had any effect on the repair of maxillofacial soft tissue defects in irradiated minipigs, ASC were isolated, characterised, and expanded. Twenty female minipigs, the right parotid glands of which had been irradiated, were randomly divided into 4 groups of 5 each: those in the first group were injected with both ASC and PRF (combined group), the second group was injected with ASC alone (ASC group), the third group with PRF alone (PRF group), and the fourth group with phosphate buffer saline (PBS) (control group). Six months after the last injection, the size and depth of each defect were assessed, and subcutaneous tissues were harvested, stained with haematoxylin and eosin, and examined immunohistologically and for apoptosis. Expanded cells were successfully isolated and identified. Six months after injection the defects in the 3 treated groups were significantly smaller (p<0.001) and shallower (p<0.001) than those in the control group. Those in the combined group were the smallest and shallowest. Haematoxylin and eosin showed that the 3 treated groups contained more subcutaneous adipose tissue than the control group, and also had significantly greater vascular density (p<0.001) and fewer apoptotic cells (p<0.001). Both ASC and PRF facilitate the repair of defects in maxillofacial soft tissue in irradiated minipigs, and their combined use is more effective than their use as single agents. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Randomized, double-blind, comparative-effectiveness study comparing pulsed radiofrequency to steroid injections for occipital neuralgia or migraine with occipital nerve tenderness.

Science.gov (United States)

Cohen, Steven P; Peterlin, B Lee; Fulton, Larry; Neely, Edward T; Kurihara, Connie; Gupta, Anita; Mali, Jimmy; Fu, Diana C; Jacobs, Michael B; Plunkett, Anthony R; Verdun, Aubrey J; Stojanovic, Milan P; Hanling, Steven; Constantinescu, Octav; White, Ronald L; McLean, Brian C; Pasquina, Paul F; Zhao, Zirong

2015-12-01

Occipital neuralgia (ON) is characterized by lancinating pain and tenderness overlying the occipital nerves. Both steroid injections and pulsed radiofrequency (PRF) are used to treat ON, but few clinical trials have evaluated efficacy, and no study has compared treatments. We performed a multicenter, randomized, double-blind, comparative-effectiveness study in 81 participants with ON or migraine with occipital nerve tenderness whose aim was to determine which treatment is superior. Forty-two participants were randomized to receive local anesthetic and saline, and three 120 second cycles of PRF per targeted nerve, and 39 were randomized to receive local anesthetic mixed with deposteroid and 3 rounds of sham PRF. Patients, treating physicians, and evaluators were blinded to interventions. The PRF group experienced a greater reduction in the primary outcome measure, average occipital pain at 6 weeks (mean change from baseline -2.743 ± 2.487 vs -1.377 ± 1.970; P occipital pain through 3 months (mean change from baseline -1.925 ± 3.204 vs -0.541 ± 2.644; P = 0.043), and average overall headache pain through 6 weeks (mean change from baseline -2.738 ± 2.753 vs -1.120 ± 2.1; P = 0.037). Adverse events were similar between groups, and few significant differences were noted for nonpain outcomes. We conclude that although PRF can provide greater pain relief for ON and migraine with occipital nerve tenderness than steroid injections, the superior analgesia may not be accompanied by comparable improvement on other outcome measures.

Electrochemical Sensing of Total Antioxidant Capacity and Polyphenol Content in Wine Samples Using Amperometry Online-Coupled with Microdialysis

Czech Academy of Sciences Publication Activity Database

Jakubec, P.; Bančíčová, M.; Halouzka, V.; Lojek, Antonín; Číž, Milan; Denev, P.; Cibiček, N.; Vacek, J.; Vostálová, J.; Ulrichová, J.; Hrbáč, J.

2012-01-01

Roč. 60, č. 32 (2012), s. 7836-7843 ISSN 0021-8561 Grant - others:GA ČR(CZ) GAP303/12/G163; GA MPO(CZ) FR-TI4/457; PrF(CZ) PrF_2011_025 Program:GA Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : wine * antioxidant capacity * phenolics Subject RIV: BO - Biophysics Impact factor: 2.906, year: 2012

Summer School and Conference : Computations with Modular Forms

CERN Document Server

Wiese, Gabor

2014-01-01

This volume contains original research articles, survey articles and lecture notes related to the Computations with Modular Forms 2011 Summer School and Conference, held at the University of Heidelberg. A key theme of the Conference and Summer School was the interplay between theory, algorithms and experiment. The 14 papers offer readers both, instructional courses on the latest algorithms for computing modular and automorphic forms, as well as original research articles reporting on the latest developments in the field. The three Summer School lectures provide an introduction to modern algorithms together with some theoretical background for computations of and with modular forms, including computing cohomology of arithmetic groups, algebraic automorphic forms, and overconvergent modular symbols. The 11 Conference papers cover a wide range of themes related to computations with modular forms, including lattice methods for algebraic modular forms on classical groups, a generalization of the Maeda conjecture, ...

Plagiarism: An Egregious Form of Misconduct

Science.gov (United States)

Juyal, Deepak; Thawani, Vijay; Thaledi, Shweta

2015-01-01

Background: Publishing research papers for academic fraternity has become important for career advancement and promotion. Number of publications in peer reviewed journals and subsequent citations are recognized as measures of scientific success. Non-publishing academicians and researchers are invisible to the scientific community. Discussion: With pressure to publish, misconduct has crept into scientific writing with the result that research misconduct, plagiarism, misappropriation of intellectual property, and substantial unattributed textual copying of another's publication have become common. The Office of Research Integrity, USA, defines research misconduct as “fabrication, falsification or plagiarism in proposing, performing or reviewing research, or in reporting research results.” Although plagiarism is difficult to define in few words, it can be viewed as the stealing of another person's ideas, methods, results, or words without giving proper attribution. The Office of Research Integrity defines plagiarism as being “theft or misappropriation of intellectual property and the substantial unattributed textual copying of another's work.” Plagiarism is one of the most vehemently derided breaches of research integrity as it undermines the original and honest contribution to an existing body of knowledge. Conclusion: Plagiarism has many forms viz. blatant plagiarism, technical plagiarism, patchwork plagiarism, and self-plagiarism. In any form, the plagiarism is a threat to the research integrity and is unacceptable. We do need to detect such acts and effectively prosecute the offenders. PMID:25789254

Plagiarism: an egregious form of misconduct.

Science.gov (United States)

Juyal, Deepak; Thawani, Vijay; Thaledi, Shweta

2015-02-01

Publishing research papers for academic fraternity has become important for career advancement and promotion. Number of publications in peer reviewed journals and subsequent citations are recognized as measures of scientific success. Non-publishing academicians and researchers are invisible to the scientific community. With pressure to publish, misconduct has crept into scientific writing with the result that research misconduct, plagiarism, misappropriation of intellectual property, and substantial unattributed textual copying of another's publication have become common. The Office of Research Integrity, USA, defines research misconduct as "fabrication, falsification or plagiarism in proposing, performing or reviewing research, or in reporting research results." Although plagiarism is difficult to define in few words, it can be viewed as the stealing of another person's ideas, methods, results, or words without giving proper attribution. The Office of Research Integrity defines plagiarism as being "theft or misappropriation of intellectual property and the substantial unattributed textual copying of another's work." Plagiarism is one of the most vehemently derided breaches of research integrity as it undermines the original and honest contribution to an existing body of knowledge. Plagiarism has many forms viz. blatant plagiarism, technical plagiarism, patchwork plagiarism, and self-plagiarism. In any form, the plagiarism is a threat to the research integrity and is unacceptable. We do need to detect such acts and effectively prosecute the offenders.

Revascularization Induced Maturogenesis of Non-Vital Immature Permanent Tooth Using Platelet-Rich-Fibrin: A Case Report.

Science.gov (United States)

Nagaveni, N B; Pathak, Sidhant; Poornima, P; Joshi, Jooie S

2016-01-01

The aim of this report is to describe a novel method of revascularization therapy done in a non-vital, immature permanent tooth using Platelet-rich fibrin (PRF),in a recently developed scaffold material to overcome limitations associated with the traditional method of revascularization using natural blood clot. PRF prepared from autologous blood was placed in the root canal and patient was followed up regularly at one, three, six, nine and 12 months for detailed clinical and radiographic evaluation. At 12 months, radiographic examination revealed root elongation, root end closure, continued thickening of the root dentinal walls, obliteration of root canal space, and normal periradicular anatomy. However, more long term prospective trials and histological studies are highly needed before to testify PRF a panacea for the regenerative endodontic therapy in children.

Inequalities for Differential Forms

CERN Document Server

Agarwal, Ravi P

2009-01-01

Presents a series of local and global estimates and inequalities for differential forms, in particular the ones that satisfy the A-harmonic equations. This work focuses on the Hardy-Littlewood, Poincare, Cacciooli, imbedded and reverse Holder inequalities. It is for researchers, instructors and graduate students

A numerical analysis on forming limits during spiral and concentric single point incremental forming

Science.gov (United States)

Gipiela, M. L.; Amauri, V.; Nikhare, C.; Marcondes, P. V. P.

2017-01-01

Sheet metal forming is one of the major manufacturing industries, which are building numerous parts for aerospace, automotive and medical industry. Due to the high demand in vehicle industry and environmental regulations on less fuel consumption on other hand, researchers are innovating new methods to build these parts with energy efficient sheet metal forming process instead of conventionally used punch and die to form the parts to achieve the lightweight parts. One of the most recognized manufacturing process in this category is Single Point Incremental Forming (SPIF). SPIF is the die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any process time to plastic deformation zone. In the present work, finite element method (FEM) is applied to analyze the forming limits of high strength low alloy steel formed by single point incremental forming (SPIF) by spiral and concentric tool path. SPIF numerical simulations were model with 24 and 29 mm cup depth, and the results were compare with Nakajima results obtained by experiments and FEM. It was found that the cup formed with Nakajima tool failed at 24 mm while cups formed by SPIF surpassed the limit for both depths with both profiles. It was also notice that the strain achieved in concentric profile are lower than that in spiral profile.

Teaching Form as Form

DEFF Research Database (Denmark)

Keiding, Tina Bering

2012-01-01

understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...

Effective Management of Hexavalent Chromium (Cr+6) in DoD Organic and Inorganic Coatings Operations

Science.gov (United States)

2014-11-19

results confirm Cr6+ to Cr3+ reductions at expected levels • Additional dwell time and saturated cloth wipes expected to increase efficiency and...Stress crazing of MIL-PRF-5425 and MIL-PRF-25690 (Type A and C) acrylic plastics 3.10 Stress crazing of polycarbonate plastics 3.11 Long term storage...Spent Plating Solution Extractant with Iron Purified Plating Solution Recycle of iron-laden stripping solution Selective Extraction of Iron

Platelet-Released Growth Factors Induce Differentiation of Primary Keratinocytes

OpenAIRE

Bayer, Andreas; Tohidnezhad, Mersedeh; Lammel, Justus; Lippross, Sebastian; Behrendt, Peter; Klüter, Tim; Pufe, Thomas; Jahr, Holger; Cremer, Jochen; Rademacher, Franziska; Gläser, Regine; Harder, Jürgen

2017-01-01

Autologous thrombocyte concentrate lysates, for example, platelet-released growth factors, (PRGFs) or their clinically related formulations (e.g., Vivostat PRF?) came recently into the physicians' focus as they revealed promising effects in regenerative and reparative medicine such as the support of healing of chronic wounds. To elucidate the underlying mechanisms, we analyzed the influence of PRGF and Vivostat PRF on human keratinocyte differentiation in vitro and on epidermal differentiatio...

Logarithmic axicon characterized by scanning optical probe system.

Science.gov (United States)

Cao, Zhaolou; Wang, Keyi; Wu, Qinglin

2013-05-15

A scanning optical probe system is proposed to measure a logarithmic axicon (LA) with subwavelength resolution. Multiple plane intensity profiles measured by a fiber probe are interpreted by solving an optimization problem to get the phase retardation function (PRF) of the LA. Experimental results show that this approach can accurately obtain the PRF with which the optical path difference of the generated quasi-nondiffracting beam in the propagation is calculated.

Polyphony and verb forms

Directory of Open Access Journals (Sweden)

Jelena Rajić

2012-12-01

Full Text Available This paper examines some special uses of indicative and subjunctive verb forms in Spanish, which contemporary linguistics explains using the notions of polyphony, evidentials, echoic representation, quotatives, etc. These terms, even though they refer to different characteristics and belong to different theoretical frameworks, share one common feature: they all refer to diverse linguistic forms (discourse markers, linguistic negation, quotatives, echoic utterances, etc. characterized by the presence and interaction of different voices or points of view in one discourse sequence. In this study we are interested in a description of quotative or polyphonic meanings expressed by specific verb forms and tenses, the imperfect and the conditional, and also by indicative forms in subordinate substantive clauses with a negative main verb and by subjunctive forms in subordinate concessive clauses. Our research focuses on the analysis of the linguistic conditions that make possible the evidential use of the conditional, the imperfect and the echoic (metarepresentative interpretation of indicative and subjunctive forms in the above-mentioned contexts. The examples we discuss show that evidential and echoic interpretations are inferential meanings derived from the extralinguistic situation and the knowledge that speakers have of the world.

Form and function relationships revealed by long-term research in a semiarid mountain catchment

Science.gov (United States)

McNamara, J. P.; Benner, S. G.; Chandler, D. G.; Flores, A. N.; Marshall, H. P.; Seyfried, M. S.; Poulos, M. J.; Pierce, J. L.

2017-12-01

Fifteen years of cumulative research in the Dry Creek Experimental Watershed in southwest Idaho, USA has revealed relationships between catchment form and function and contributed to improved fundamental understanding of Critical Zone structure, function, and evolution that would not have been possible through independent short term projects alone. The impacts of aspect and elevation on incident energy and water, coupled with climate seasonality, has produced tightly connected landforms properties and hydrologic processes. North-facing hillslopes have steeper slopes, thicker soil mantles, and finer soil texture than their south-facing counterparts. Finer soils enable higher water holding capacities on north facing slopes, which when coupled with thicker soils produces higher soil water storage capacity. The storage of water first as snow, then as soil moisture determines how upland ecosystems survive the seasonal and persistent water stress that happens each year, and sustains streamflow throughout the year. The cumulative body of local knowledge has improved general understanding of catchment science, serves as a resource for developing, evaluating, and improving conceptual and numerical of process-based models, and for data-driven hydrologic education.

Readability of informed consent forms in clinical trials conducted in a skin research center

Science.gov (United States)

Samadi, Aniseh; Asghari, Fariba

2016-01-01

Obtaining informed consents is one of the most fundamental principles in conducting a clinical trial. In order for the consent to be informed, the patient must receive and comprehend the information appropriately. Complexity of the consent form is a common problem that has been shown to be a major barrier to comprehension for many patients. The objective of this study was to assess the readability of different templates of informed consent forms (ICFs) used in clinical trials in the Center for Research and Training in Skin Diseases and Leprosy (CRTSDL), Tehran, Iran. This study was conducted on ICFs of 45 clinical trials of the CRTSDL affiliated with Tehran University of Medical Sciences. ICFs were tested for reading difficulty, using the readability assessments formula adjusted for the Persian language including the Flesch–Kincaid reading ease score, Flesch–Kincaid grade level, and Gunning fog index. Mean readability score of the whole text of ICFs as well as their 7 main information parts were calculated. The mean ± SD Flesch Reading Ease score for all ICFs was 31.96 ± 5.62 that is in the difficult range. The mean ± SD grade level was calculated as 10.71 ± 1.8 (8.23–14.09) using the Flesch–Kincaid formula and 14.64 ± 1.22 (12.67–18.27) using the Gunning fog index. These results indicate that the text is expected to be understandable for an average student in the 11th grade, while the ethics committee recommend grade level 8 as the standard readability level for ICFs. The results showed that the readability scores of ICFs assessed in our study were not in the acceptable range. This means they were too complex to be understood by the general population. Ethics committees must examine the simplicity and readability of ICFs used in clinical trials. PMID:27471590

Personal Information Request Form

International Development Research Centre (IDRC) Digital Library (Canada)

PC Forms Inc. 834-4048

To apply for information under the Privacy Act, complete this form or a written request mentioning the Act. Describe the information being sought and provide any relevant details necessary to help the. International Development Research Centre. (IDRC) find it. If you require assistance, refer to. Info Source (Sources of ...

Effectiveness of platelet-rich fibrin in the management of pain and delayed wound healing associated with established alveolar osteitis (dry socket).

Science.gov (United States)

Sharma, Ashish; Aggarwal, Nimish; Rastogi, Sanjay; Choudhury, Rupshikha; Tripathi, Siddhi

2017-01-01

To assess the efficacy of platelet-rich fibrin (PRF) on the pain and healing of the extraction socket related with established alveolar osteitis (dry socket, AO) after the removal of maxillary and mandibular molars. One hundred consecutive adult patients with age group ranging from 18 to 40 years along with established dry socket after maxillary and mandibular molar extractions who have not received any treatment for the same were included in this single-arm clinical trial. PRF was placed in the maxillary and mandibular molar extraction sockets after adequate irrigation of the socket. All the patients evaluated for the various study variables which include pain, degree of inflammation, and healthy granulation tissue formation (wound healing) at the 1 st , 3 rd , 7 th , and 14 th post-PRF placement day in the alveolar socket. Data were analyzed using Shapiro-Wilk's test, Chi-square test and/or Student's t -test, Friedman's test, Wilcoxon signed-rank test, and Bonferroni test, with the significance level set at P healing by the end of the 2 nd week. The use of PRF in this clinical trial illustrates the promising results in terms of reduced pain and better healing in the patients with sustained AO.

Technique for long and absolute distance measurement based on laser pulse repetition frequency sweeping

Science.gov (United States)

Castro Alves, D.; Abreu, Manuel; Cabral, A.; Jost, Michael; Rebordão, J. M.

2017-11-01

In this work we present a technique to perform long and absolute distance measurements based on mode-locked diode lasers. Using a Michelson interferometer, it is possible to produce an optical cross-correlation between laser pulses of the reference arm with the pulses from the measurement arm, adjusting externally their degree of overlap either changing the pulse repetition frequency (PRF) or the position of the reference arm mirror for two (or more) fixed frequencies. The correlation of the travelling pulses for precision distance measurements relies on ultra-short pulse durations, as the uncertainty associated to the method is dependent on the laser pulse width as well as on a highly stable PRF. Mode-locked Diode lasers are a very appealing technology for its inherent characteristics, associated to compactness, size and efficiency, constituting a positive trade-off with regard to other mode-locked laser sources. Nevertheless, main current drawback is the non-availability of frequency-stable laser diodes. The laser used is a monolithic mode-locked semiconductor quantum-dot (QD) laser. The laser PRF is locked to an external stabilized RF reference. In this work we will present some of the preliminary results and discuss the importance of the requirements related to laser PRF stability in the final metrology system accuracy.

Clinical effectiveness of combining platelet rich fibrin with alloplastic bone substitute for the management of combined endodontic periodontal lesion.

Science.gov (United States)

Goyal, Lata

2014-02-01

The term "endo-perio" lesion has been proposed to describe the destructive lesion resulting from inflammatory products found in varying degrees in both the periodontium and the pulpal tissues. In most of the cases, clinical symptoms disappear following successful endodontic therapy. However failure after conventional root canal treatment calls for surgical intervention. A 35 year old male patient with endo-perio lesion in right maxillary lateral incisor was treated with platelet rich fibrin (PRF) and alloplastic bone substitute after conventional endodontic therapy. At the end of 6 months there was gain in clinical attachment, increased radiographic bone fill and reduction in probing depth which was maintained till 18 month follow-up. Present case report aims to evaluate the efficacy of PRF and alloplastic bone substitute in the management of intrabony defect associated with endo-perio lesion in maxillary lateral incisor because the healing potential of PRF and bone graft has not been widely studied in endodontics. The use of PRF allows the clinician to optimize tissue remodelling, wound healing and angiogenesis by the local delivery of growth factors and proteins. The novel technique described here enables the clinician to be benefited from the full regenerative capacity of this autologous biologic material.

Clinical effectiveness of combining platelet rich fibrin with alloplastic bone substitute for the management of combined endodontic periodontal lesion

Directory of Open Access Journals (Sweden)

Lata Goyal

2014-02-01

Full Text Available The term "endo-perio" lesion has been proposed to describe the destructive lesion resulting from inflammatory products found in varying degrees in both the periodontium and the pulpal tissues. In most of the cases, clinical symptoms disappear following successful endodontic therapy. However failure after conventional root canal treatment calls for surgical intervention. A 35 year old male patient with endo-perio lesion in right maxillary lateral incisor was treated with platelet rich fibrin (PRF and alloplastic bone substitute after conventional endodontic therapy. At the end of 6 months there was gain in clinical attachment, increased radiographic bone fill and reduction in probing depth which was maintained till 18 month follow-up. Present case report aims to evaluate the efficacy of PRF and alloplastic bone substitute in the management of intrabony defect associated with endo-perio lesion in maxillary lateral incisor because the healing potential of PRF and bone graft has not been widely studied in endodontics. The use of PRF allows the clinician to optimize tissue remodelling, wound healing and angiogenesis by the local delivery of growth factors and proteins. The novel technique described here enables the clinician to be benefited from the full regenerative capacity of this autologous biologic material.

Evolution, current status and advances in application of platelet concentrate in periodontics and implantology.

Science.gov (United States)

Agrawal, Amit Arvind

2017-05-16

Platelet concentrates (PC) [platelet-rich plasma (PRP) and platelet-rich fibrin (PRF)] are frequently used for surgical procedures in medical and dental fields, particularly in oral and maxillofacial surgery, plastic surgery and sports medicine. The objective of all these technologies is to extract all the elements from a blood sample that could be used to improve healing and promote tissue regeneration. Although leukocyte rich and leukocyte poor PRP's have their own place in literature, the importance of non-platelet components in a platelet concentrate remains a mystery. PC have come a long way since its first appearance in 1954 to the T-PRF, A-PRF and i-PRF introduced recently. These PC find varied applications successfully in periodontics and implant dentistry as well. However, the technique of preparation, standing time, transfer process, temperature of centrifuge, vibration, etc ., are the various factors for the mixed results reported in the literature. Until the introduction of a proper classification of terminologies, the PC were known by different names in different countries and by different commercial companies which also created a lot of confusion. This review intends to clarify all these confusion by briefing the exact evolution of PC, their preparation techniques, recent advances and their various clinical and technical aspects and applications.

The influence of platelet-rich fibrin on angiogenesis in guided bone regeneration using xenogenic bone substitutes: a study of rabbit cranial defects.

Science.gov (United States)

Yoon, Jong-Suk; Lee, Sang-Hwa; Yoon, Hyun-Joong

2014-10-01

The purpose of this study was to investigate the influence of platelet-rich fibrin (PRF) on angiogenesis and osteogenesis in guided bone regeneration (GBR) using xenogenic bone in rabbit cranial defects. In each rabbit, 2 circular bone defects, one on either side of the midline, were prepared using a reamer drill. Each of the experimental sites received bovine bone with PRF, and each of the control sites received bovine bone alone. The animals were sacrificed at 1 week (n = 4), 2 weeks (n = 3) and 4 weeks (n = 3). Biopsy samples were examined histomorphometrically by light microscopy, and expression of vascular endothelial growth factor (VEGF) was determined by immunohistochemical staining. At all experimental time points, immunostaining intensity for VEGF was consistently higher in the experimental group than in the control group. However, the differences between the control group and the experimental group were not statistically significant in the histomorphometrical and immunohistochemical examinations. The results of this study suggest that PRF may increase the number of marrow cells. However, PRF along with xenogenic bone substitutes does not show a significant effect on bony regeneration. Further large-scale studies are needed to confirm our results. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Effect of Platelet-rich Fibrin on Healing of Apicomarginal Defects: A Randomized Controlled Trial.

Science.gov (United States)

Dhiman, Meenu; Kumar, Suresh; Duhan, Jigyasa; Sangwan, Pankaj; Tewari, Sanjay

2015-07-01

The purpose of this prospective, randomized controlled trial was to evaluate the healing outcomes of platelet-rich fibrin (PRF) in periapical surgeries involving apicomarginal defects and to compare these results with surgeries not using any guided tissue regeneration techniques. Thirty patients with suppurative chronic apical periodontitis and apicomarginal communication were randomly assigned to either the PRF or the control group. Clinical and radiographic parameters including pocket depth (PD), clinical attachment level, gingival marginal position, size of periapical lesion, and percentage reduction of the periapical radiolucency were recorded at baseline and at an interval of 3 months for a period of 12 months. The overall success rate was 83.33%, with a success rate of 86.66% (13 of 15 teeth) for PRF group and 80% (12 of 15 teeth) for control group. Both the groups exhibited a significant reduction in PD, clinical attachment level, gingival marginal position, and size of periapical lesion at 12-month period. No significant differences were observed between the 2 groups for these parameters except PD, which showed a statistically significant reduction in the PRF group (P < .05). The adjunctive use of regenerative techniques may not promote healing of apicomarginal defects of endodontic origin. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Use of a platelet-rich fibrin membrane to repair traumatic tympanic membrane perforations: a comparative study.

Science.gov (United States)

Gür, Özer Erdem; Ensari, Nuray; Öztürk, Mehmet Türker; Boztepe, Osman Fatih; Gün, Taylan; Selçuk, Ömer Tarık; Renda, Levent

2016-10-01

(1) To evaluate the effects of a platelet-rich fibrin (PRF) membrane in the repair of traumatic tympanic membrane (TM) perforations; and (2) to compare the use of a PRF membrane with the paper patch technique with regard to recovery rates, healing time, and correction of the mean air-bone gap. A randomized, prospective analysis was performed for 60 patients who were treated for traumatic TM perforations using one of the two methods. Closure rate, speed of healing, and hearing gain were compared between the PRF (Group 1) and paper patch (Group 2) groups. Closure was obtained in 28 (93%) perforations in Group 1 and 25 (83%) perforations in Group 2 (p > 0.05). On day 10, full closure of the TM was observed in 24 (80%) patients in Group 1 and 16 (53%) patients in Group 2 (p < 0.05). The improvement in the mean air-bone gap was 14.1 dB in Group 1 and 12.4 dB in Group 2 on post-operative day 45 (p < 0.05). In comparison with the paper patch method, PRF, a new method, provided more rapid healing with more successful audiological results, and with no requirement for a second procedure.

Long-term follow up of revascularization using platelet-rich fibrin.

Science.gov (United States)

Ray, Herbert L; Marcelino, Janel; Braga, Raquel; Horwat, Richard; Lisien, Michael; Khaliq, Shahryar

2016-02-01

Trauma is one of the primary causes of tooth loss and pulpal injury in adolescents and children. Prior to regenerative endodontics, treatment of necrotic, immature teeth with open apices was limited to long-term calcium hydroxide (Ca(OH)2 ) apexification and subsequent root canal therapy or extraction. Through revascularization, retention of these teeth can be achieved and the elimination of patient symptoms and the radiographic appearance of continued root development were obtained. This report illustrates a revascularization protocol through a case where platelet-rich fibrin (PRF) was utilized as an autologous scaffold for traumatized, necrotic, immature teeth with incomplete root development. Through consistent follow-up reports, comprising of both clinical examination and radiographs, marked improvement in the condition of the traumatized tooth was noted. This case demonstrates the feasibility of utilizing PRF as an effective treatment protocol for traumatized teeth in lieu of traditional treatment protocols, such as long-term calcium hydroxide (Ca(OH)2 ) apexification or extraction. The choice of utilizing PRF, as opposed to other platelet concentrates, such as platelet-rich plasma (PRP) or a blood clot, lies in PRF's ability to allow for a slow, long-term release of autologous growth factors. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Blood-Forming Stem Cell Transplants

Science.gov (United States)

... to Ask about Your Treatment Research Blood-Forming Stem Cell Transplants On This Page What are bone marrow ... Considering becoming a bone marrow or a blood stem cell donor? View this video on YouTube. Follow a ...

Effect of runway training on rat brain tyrosine hydroxylase: differential effect of continuous and partial reinforcement schedules.

Science.gov (United States)

Boarder, M R; Feldon, J; Gray, J A; Fillenz, M

1979-12-01

Previous experiments have implicated ascending noradrenergic systems in the development of the behavioural responses to different patterns of reward. In this report food deprived male Sprague--Dawley rats were trained to run a straight alley for good reward on a continuous reinforcement (CRF) or a partial reinforcement (PRF) schedule. Tyrosine hydroxylase measured in a partially solubilized preparation from hippocampus and hypothalamus at the end of acquisition was not different from controls, indicating that enzyme induction does not occur during either training schedules. However, hippocampal synaptosomal tyrosine hydroxylation rates from the CRF group was significantly higher than from either the PRF group or the handled controls. This indicates that at the end of the acquisition schedule the noradrenergic projection to hippocampus was more active in the CRF group than with the PRF group or the handled control.

[Contribution of platelet concentrates to oral and maxillo-facial surgery].

Science.gov (United States)

Bettega, G; Schir, E

2012-09-01

We evaluated the clinical contribution of platelet concentrates to oral and maxillo-facial surgery. This bibliographic research was made using the PubMed MeSH database with the following keywords: "platelet rich fibrin" (PRF), "platelet rich plasma" (PRP), "bone", "facial bone", "dental implant", and "blood platelet". The research was made without any date or language limitation since English summaries were available. All summaries were read to evaluate the relevance of the article. Only original articles and case reports were considered. The articles were classified as "in vitro studies", "animal experiments", or "clinical studies". The research was stopped on March 22, 2012. One hundred and sixty-nine articles were validated after excluding irrelevant articles, reviews, technical notes, and articles without English or French summaries. Seventeen were in vitro studies, 61 animal experiments, and 91 clinical studies. One hundred and ten complete articles were read to complete summary data. The data of in vitro studies univocally supports of using platelet concentrates. The data from animal experiment studies was less consensual and the validity of animal models was contested. The disparity of clinical study designs and the lack of rigorous methodology did not allow clearly determining platelet concentrate benefits for oral and maxillo-facial surgery. PRF or PRP clinical benefit has not been clearly demonstrated yet. French regulations relative to their use should be clarified. Copyright © 2012. Published by Elsevier Masson SAS.

AI applications in sheet metal forming

CERN Document Server

Hussein, Hussein

2017-01-01

This book comprises chapters on research work done around the globe in the area of artificial intelligence (AI) applications in sheet metal forming. The first chapter offers an introduction to various AI techniques and sheet metal forming, while subsequent chapters describe traditional procedures/methods used in various sheet metal forming processes, and focus on the automation of those processes by means of AI techniques, such as KBS, ANN, GA, CBR, etc. Feature recognition and the manufacturability assessment of sheet metal parts, process planning, strip-layout design, selecting the type and size of die components, die modeling, and predicting die life are some of the most important aspects of sheet metal work. Traditionally, these activities are highly experience-based, tedious and time consuming. In response, researchers in several countries have applied various AI techniques to automate these activities, which are covered in this book. This book will be useful for engineers working in sheet metal industri...

Pulsed Radiofrequency Application for the Treatment of Pain Secondary to Sacroiliac Joint Metastases

OpenAIRE

Yi, Yu Ri; Lee, Na Rea; Kwon, Young Suk; Jang, Ji Su; Lim, So Young

2016-01-01

Sacroiliac (SI) joint pain can result from degeneration, infection, malignancy, and trauma. Patients with metastatic bone pain who do not respond to conventional treatment may need more aggressive neuroinvasive approaches. Recently, pulsed radiofrequency (PRF) neuromodulation has emerged as a promising treatment alternative for refractory cases of SI joint pain. Nevertheless, there is no report on the treatment of pain arising from SI joint metastases with PRF. We are reporting about a 63-yea...

Increasing the Robustness of the Sheet Metal Forming Simulation by the Prediction of the Forming Limit Band

Science.gov (United States)

Banabic, D.; Vos, M.; Paraianu, L.; Jurco, P.

2007-05-01

The experimental research on the formability of metal sheets has shown that there is a significant dispersion of the limit strains in an area delimited by two curves: a lower curve (LFLC) and an upper one (UFLC). The region between the two curves defines the so-called Forming Limit Band (FLB). So far, this forming band has only been determined experimentally. In this paper the authors suggested a method to predict the Forming Limit Band. The proposed method is illustrated on the AA6111-T43 aluminium alloy.

Increasing the Robustness of the Sheet Metal Forming Simulation by the Prediction of the Forming Limit Band

International Nuclear Information System (INIS)

Banabic, D.; Paraianu, L.; Vos, M.; Jurco, P.

2007-01-01

The experimental research on the formability of metal sheets has shown that there is a significant dispersion of the limit strains in an area delimited by two curves: a lower curve (LFLC) and an upper one (UFLC). The region between the two curves defines the so-called Forming Limit Band (FLB). So far, this forming band has only been determined experimentally. In this paper the authors suggested a method to predict the Forming Limit Band. The proposed method is illustrated on the AA6111-T43 aluminium alloy

EMERGING TRENDS IN TOURISM: NEED FOR ALTERNATIVE FORMS IN MACEDONIAN TOURISM

Directory of Open Access Journals (Sweden)

Nikola Cuculeski

2015-11-01

Full Text Available The purpose of this paper is to research the development of tourism, taking into consideration the growing competition and new consumer intentions. The aim of this research is to analyze the alternative forms of tourism as a crucial factor for long term sustainability. As a basic research method used is an interview with tourist providers in Macedonia (travel agencies – DMC companies and tourist guides, regarding their experience for alternative tourism forms. Results are showing growing trend of alternative forms of tourism considering different tourist nationalities. These results are valuable for further scientific research in consumer analyzes, and presents an input for the national tourism in this region.

Survey of concrete waste forms

International Nuclear Information System (INIS)

Moore, J.G.

1981-01-01

The incorporation of radioactive waste in cement has been widely studied for many years. It has been routinely used at nuclear research and production sites for some types of nuclear waste for almost three decades and at power reactor plants for nearly two decades. Cement has many favorable characteristics that have contributed to its popularity. It is a readily available material and has not required complex and/or expensive equipment to solidify radioactive waste. The resulting solid products are noncombustible, strong, radiation resistant, and have reasonable chemical and thermal stability. As knowledge increased on the possible dangers from radioactive waste, requirements for waste fixation became more stringent. A brief survey of some of the research efforts used to extend and improve cementitious waste hosts to meet these requirements is given in this paper. Selected data are presented from the rather extensive study of the applicability of concrete as a waste form for Savannah River defense waste and the use of polymer impregnation to reduce the leachability and improve the durability of such waste forms. Hot-pressed concretes that were developed as prospective host solids for high-level wastes are described. Highlights are given from two decades of research on cementitious waste forms at Oak Ridge National Laboratory. The development of the hydrofracture process for the disposal of all locally generated radioactive waste led to a process for the disposal of I-129 and to the current research on the German in-situ solidification process for medium-level waste and the Oak Ridge FUETAP process for all classes of waste including commercial and defense high-level wastes. Finally, some of the more recent ORNL concepts are presented for the use of cement in the disposal of inorganic and biological sludges, waste inorganic salts, trash, and krypton

75 FR 54217 - Reports, Forms, and Recordkeeping Requirements

Science.gov (United States)

2010-09-03

..., NHTSA will conduct two types of qualitative research. One research project will consist of two (2) focus... Information Regulations (sections 103 and 105) Qualitative Research. OMB Control Number: Not Assigned. Form... the following methods: Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the...

MODERN FORMS OF PARTNERSHIP IN BUSINESS

OpenAIRE

Markova V. D.; Trapeznikov I. S.

2016-01-01

The article examines tendencies of the development of new organizational forms of partnership and marks several problems of their usage in Russian conditions by the example of the Novosibirsk region. Modern forms of networking and partnership of commercial companies and universities, research institutes and other organizations, such as clusters, strategic alliances, technology platforms, business ecosystems and other, are focused on the development of new market opportunities and gaining comp...

Alternate nuclear waste forms and interactions in geologic media

International Nuclear Information System (INIS)

Boatner, L.A.; Battle, G.C. Jr.

1981-04-01

The primary purposes of the conference on Alternate Nuclear Waste Forms and Interactions in Geologic Media were: First, to provide an opportunity for a review of the status of the research on some of the candidate alternative waste forms; second, to provide an opportunity for comparing the characteristics of alternate waste forms to those of glasses; and third, to stimulate increased interactions between those research groups that were engaged in a more basic approach to characterizing waste forms and those who were concerned with more applied aspects such as the processing of these materials. The motivating philosophy behind this third purpose of the conference was based on the idea that by operating from the soundest possible fundamental base for any of the candidate waste forms, hopefully any future unpleasant surprise - such as that alluded to earlier in the case of glass waste forms - could be avoided. Separate abstracts have been prepared for individual papers for inclusion in the Energy Data Base

Plutonium Finishing Plant (PFP) Final Safety Analysis Report (FSAR) [SEC 1 THRU 11

Energy Technology Data Exchange (ETDEWEB)

ULLAH, M K

2001-02-26

The Plutonium Finishing Plant (PFP) is located on the US Department of Energy (DOE) Hanford Site in south central Washington State. The DOE Richland Operations (DOE-RL) Project Hanford Management Contract (PHMC) is with Fluor Hanford Inc. (FH). Westinghouse Safety Management Systems (WSMS) provides management support to the PFP facility. Since 1991, the mission of the PFP has changed from plutonium material processing to preparation for decontamination and decommissioning (D and D). The PFP is in transition between its previous mission and the proposed D and D mission. The objective of the transition is to place the facility into a stable state for long-term storage of plutonium materials before final disposition of the facility. Accordingly, this update of the Final Safety Analysis Report (FSAR) reflects the current status of the buildings, equipment, and operations during this transition. The primary product of the PFP was plutonium metal in the form of 2.2-kg, cylindrical ingots called buttoms. Plutonium nitrate was one of several chemical compounds containing plutonium that were produced as an intermediate processing product. Plutonium recovery was performed at the Plutonium Reclamation Facility (PRF) and plutonium conversion (from a nitrate form to a metal form) was performed at the Remote Mechanical C (RMC) Line as the primary processes. Plutonium oxide was also produced at the Remote Mechanical A (RMA) Line. Plutonium processed at the PFP contained both weapons-grade and fuels-grade plutonium materials. The capability existed to process both weapons-grade and fuels-grade material through the PRF and only weapons-grade material through the RMC Line although fuels-grade material was processed through the line before 1984. Amounts of these materials exist in storage throughout the facility in various residual forms left from previous years of operations.

Cold rolling precision forming of shaft parts theory and technologies

CERN Document Server

Song, Jianli; Li, Yongtang

2017-01-01

This book presents in detail the theory, processes and equipment involved in cold rolling precision forming technologies, focusing on spline and thread shaft parts. The main topics discussed include the status quo of research on cold rolling precision forming technologies; the design and calculation of process parameters; the numerical simulation of cold rolling forming processes; and the equipment used in cold rolling forming. The mechanism of cold rolling forming is extremely complex, and research on the processes, theory and mechanical analysis of spline cold rolling forming has remained very limited to date. In practice, the forming processes and production methods used are mainly chosen on the basis of individual experience. As such, there is a marked lack of both systematic, theory-based guidelines, and of specialized books covering theoretical analysis, numerical simulation, experiments and equipment used in spline cold rolling forming processes – all key points that are included in this book and ill...

Disability and Bureaucratic Forms of Life

Directory of Open Access Journals (Sweden)

Thomas Abrams

2015-06-01

Full Text Available This paper employs a hybrid actor-network theory/phenomenological approach to a frequent bother in the lives of disabled persons: bureaucratic forms. I argue that these forms are key sites where disabled personhood emerges, something I examine through the lens of what philosopher Annemarie Mol calls ‘ontological politics’. To be disabled is to be entered into the bureaucratic form of life. These forms translate human existence into a categorize-able, transportable and combinable object, to be administered through ‘centers of calculation’. Combining Heidegger’s fundamental ontology with Latour’s theory of paperwork, I suggest that these forms represent disability in terms of ‘objective presence’, as a mere pre-existing thing, rather than a human way of being. I conclude with suggestions for further phenomenological research that takes embodied difference as its point of departure.

Management of an endo-perio lesion in an immature tooth using autologous platelet-rich fibrin: A case report

OpenAIRE

N B Nagaveni; K Nandini Kumari; P Poornima; VV Subba Reddy

2015-01-01

Treatment of an endo-perio lesion involving a non-vital young permanent tooth is a highly challenging task to Pediatric Dentists. There is a quest for the newer biological approach to management of these lesions as traditional methods have various disadvantages. Recently, platelet-rich fibrin (PRF), a second-generation platelet concentrate, is rich in growth factors have been used in the periodontal regeneration procedure. The purpose of this paper is to describe the efficacy of PRF in the tr...

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial

OpenAIRE

Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K.

2015-01-01

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in...

Minería de datos y la calidad de los conocimientos extraídos de informes policiales de carreteras federales brasileñas

OpenAIRE

Costa, Jefferson de Jesus; Bernardini, Flávia Cristina; Viterbo Filho, José

2014-01-01

Introduction: This paper presents and analyzes the results obtained when applying Data Mining process in the bulletins of occurrences of the Brazilian federal highways generated by the Federal Highway Police (PRF) in 2012. The purpose of this work is to analyze the feasibility of implementing the Data Mining process on data provided by PRF in order to identify associations between variables related to transit accidents in all Brazilian federal highways. Method: It was used symbolic supervised...

Incorporating AFEWC IMOM as an Instructional Asset for NPS Radar and Electronic Warfare Curricula

Science.gov (United States)

1992-09-01

Backlobe EL. dB down - 20 dB Backlobe AZ. dB down = 20 dB Ru - 400 km 215.983 nmi Scope Range = 200 km 107.991 nmi PRF = 375 Hz Pay = 600 W RCS = 10 sq m...10 dB Backlobe EL. dB down = 20 dB Backlobe AZ. dB down = 20 dB Ru = 400 km 215.983 nmi Scope Range = 400 km 215.983 nmi PRF = 375 Hz Pay = 93.75 W

Management of an endo-perio lesion in an immature tooth using autologous platelet-rich fibrin: a case report.

Science.gov (United States)

Nagaveni, N B; Kumari, K Nandini; Poornima, P; Reddy, V V Subba

2015-01-01

Treatment of an endo-perio lesion involving a non-vital young permanent tooth is a highly challenging task to Pediatric Dentists. There is a quest for the newer biological approach to management of these lesions as traditional methods have various disadvantages. Recently, platelet-rich fibrin (PRF), a second-generation platelet concentrate, is rich in growth factors have been used in the periodontal regeneration procedure. The purpose of this paper is to describe the efficacy of PRF in the treatment of a deep intra bony defect associated with an endo-perio lesion in an immature right mandibular first premolar of 12-year-old female patient. A freshly prepared autologous PRF membrane was placed in the bony defect following debridement. Clinical and radiographic follow-up were performed at regular intervals that revealed absence of pain, gain in clinical attachment level, reduction in probing depth, and excellent bone regeneration indicating successful outcome.

Development of laser diode-pumped high average power solid-state laser for the pumping of Ti:sapphire CPA system

Energy Technology Data Exchange (ETDEWEB)

Maruyama, Yoichiro; Tei, Kazuyoku; Kato, Masaaki; Niwa, Yoshito; Harayama, Sayaka; Oba, Masaki; Matoba, Tohru; Arisawa, Takashi; Takuma, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Laser diode pumped all solid state, high repetition frequency (PRF) and high energy Nd:YAG laser using zigzag slab crystals has been developed for the pumping source of Ti:sapphire CPA system. The pumping laser installs two main amplifiers which compose ring type amplifier configuration. The maximum amplification gain of the amplifier system is 140 and the condition of saturated amplification is achieved with this high gain. The average power of fundamental laser radiation is 250 W at the PRF of 200 Hz and the pulse duration is around 20 ns. The average power of second harmonic is 105 W at the PRF of 170 Hz and the pulse duration is about 16 ns. The beam profile of the second harmonic is near top hat and will be suitable for the pumping of Ti:sapphire laser crystal. The wall plug efficiency of the laser is 2.0 %. (author)

Pulsed radiofrequency of brachial plexus under ultrasound guidance for refractory stump pain: a case report

Directory of Open Access Journals (Sweden)

Zheng B

2017-11-01

Full Text Available Bixin Zheng, Li Song, Hui Liu Department of Pain Management, West China Hospital of Sichuan University, Chengdu, China Abstract: The post-amputation (pain syndrome, including stump pain, phantom limb sensation, and phantom limb pain is common but difficult to treat. Refractory stump pain in the syndrome is an extremely challenging and troublesome clinical condition. Patients respond poorly to drugs, nerve blocks, and other effective treatments like spinal cord stimulation and surgery. Pulsed radiofrequency (PRF technique has been shown to be effective in reducing neuropathic pain. This report describes a patient with persistent and refractory upper limb stump pain being successfully relieved with PRF of brachial plexus under ultrasound guidance after a 6-month follow-up period, suggesting that PRF may be considered as an alternative treatment for refractory stump-neuroma pain. Keywords: ultrasound guidance, pulsed radiofrequency, brachial plexus, refractory stump pain 

A new technique of characterization of intrapixel response dedicated to astronomical detectors

International Nuclear Information System (INIS)

Ketchazo, C.; Viale, T.; Boulade, O.; Druart, G.; Moreau, V.; Mugnier, L.; Dubrueil, D.; Derelle, S.; Ronayette, S.; Guérineau, N.; Berthé, M.

2015-01-01

This paper is devoted to the presentation of a new technique of characterization of the intra-pixel sensitivity variations (IPSVs) of astronomical detectors. The IPSV is the spatial variation of the pixel response function (PRF). In the case of under-sampled instruments for high quality imaging and accurate photometry, IPSV can contribute to the instrument global error and it should be considered carefully. Our measurement technique is based in the Fourier transform (FT) approach. It consists into the sampling of the pixel transfer function (PTF) by projecting high-resolution periodic patterns onto the whole sensor without classic optics but using the self-imaging property (the Talbot effect) of a continuously self imaging grating (CSIG) illuminated by a plane wave. The PRF is determined by computing the inverse FT. Our measurement technique permits to determine the PRF with a resolution of pixel/10 (10 times Nyquist frequency)

Direct numerical simulations of the ignition of lean primary reference fuel/air mixtures with temperature inhomogeneities

KAUST Repository

Luong, Minhbau

2013-10-01

The effects of fuel composition, thermal stratification, and turbulence on the ignition of lean homogeneous primary reference fuel (PRF)/air mixtures under the conditions of constant volume and elevated pressure are investigated by direct numerical simulations (DNSs) with a new 116-species reduced kinetic mechanism. Two-dimensional DNSs were performed in a fixed volume with a two-dimensional isotropic velocity spectrum and temperature fluctuations superimposed on the initial scalar fields with different fuel compositions to elucidate the influence of variations in the initial temperature fluctuation and turbulence intensity on the ignition of three different lean PRF/air mixtures. In general, it was found that the mean heat release rate increases slowly and the overall combustion occurs fast with increasing thermal stratification regardless of the fuel composition under elevated pressure and temperature conditions. In addition, the effect of the fuel composition on the ignition characteristics of PRF/air mixtures was found to vanish with increasing thermal stratification. Chemical explosive mode (CEM), displacement speed, and Damköhler number analyses revealed that the high degree of thermal stratification induces deflagration rather than spontaneous ignition at the reaction fronts, rendering the mean heat release rate more distributed over time subsequent to thermal runaway occurring at the highest temperature regions in the domain. These analyses also revealed that the vanishing of the fuel effect under the high degree of thermal stratification is caused by the nearly identical propagation characteristics of deflagrations of different PRF/air mixtures. It was also found that high intensity and short-timescale turbulence can effectively homogenize mixtures such that the overall ignition is apt to occur by spontaneous ignition. These results suggest that large thermal stratification leads to smooth operation of homogeneous charge compression-ignition (HCCI

Evaluation of conditioned high-level waste forms

International Nuclear Information System (INIS)

Mendel, J.E.; Turcotte, R.P.; Chikalla, T.D.; Hench, L.L.

1983-01-01

The evaluation of conditioned high-level waste forms requires an understanding of radiation and thermal effects, mechanical properties, volatility, and chemical durability. As a result of nuclear waste research and development programs in many countries, a good understanding of these factors is available for borosilicate glass containing high-level waste. The IAEA through its coordinated research program has contributed to this understanding. Methods used in the evaluation of conditioned high-level waste forms are reviewed. In the US, this evaluation has been facilitated by the definition of standard test methods by the Materials Characterization Center (MCC), which was established by the Department of Energy (DOE) in 1979. The DOE has also established a 20-member Materials Review Board to peer-review the activities of the MCC. In addition to comparing waste forms, testing must be done to evaluate the behavior of waste forms in geologic repositories. Such testing is complex; accelerated tests are required to predict expected behavior for thousands of years. The tests must be multicomponent tests to ensure that all potential interactions between waste form, canister/overpack and corrosion products, backfill, intruding ground water and the repository rock, are accounted for. An overview of the status of such multicomponent testing is presented

Organizational forms and knowledge absorption

Directory of Open Access Journals (Sweden)

Radovanović Nikola

2016-01-01

Full Text Available Managing the entire portion of knowledge in an organization is a challenging task. At the organizational level, there can be enormous quantities of unknown, poorly valued or inefficiently applied knowledge. This is normally followed with the underdeveloped potential or inability of organizations to absorb knowledge from external sources. Facilitation of the efficient internal flow of knowledge within the established communication network may positively affect organizational capacity to absorb or identify, share and subsequently apply knowledge to commercial ends. Based on the evidences that the adoption of different organizational forms affects knowledge flows within an organization, this research analyzed the relationship between common organizational forms and absorptive capacity of organizations. In this paper, we test the hypothesis stating that the organizational structure affects knowledge absorption and exploitation in the organization. The methodology included quantitative and qualitative research method based on a questionnaire, while the data has been statistically analyzed and the hypothesis has been tested with the use of cross-tabulation and chi-square tests. The findings suggest that the type of organizational form affects knowledge absorption capacity and that having a less formalized and more flexible structure in an organization increases absorbing and exploiting opportunities of potentially valuable knowledge.

Action Research and Interactive Research

DEFF Research Database (Denmark)

First part of the book is written by senior researchers on specific issues like validity, gender, new forms of organisations, methodologies and methods, earlier and new trends. - The second part of the book is written by doctoral students reporting experiences doing action research in their PhD-projects....

A research on determining the friction losses formed in the small ...

African Journals Online (AJOL)

fastest way is to make use of the values given in the tables or diagrams determined by the equation of Hazen-Williams. However, no data related to floppy polythene (PE) pipes with small diameter is available in the tables and diagrams mentioned. In this study, values relating to friction losses and pressures formed in 10, 20, ...

ALTERNATIVE FORMS OF COMMUNICATION AMONG PERSONS WITH APHASIA

Directory of Open Access Journals (Sweden)

Elena TASHKOVA

2012-03-01

Full Text Available The aphasia is the most complicated and the most difficult form of disorder of speaking and language. Most often it appears as a consequence of a brain stroke. The occurrence of aphasias is in about one third of the patients suffering from a brain stroke in an acute phase, or from 21% to 24%, and there are data for even bigger frequency. In a certain number of patients the aphasia withdraws spontaneously, but in a bigger number of patients it takes over all four models of language activity; phoneme pronunciation, carrying out a discussion, writing a letter of a full text. It spreads from the automatic to the creative expression. The process of rehabilitation of the spoken communication at the persons with aphasia is complicated, multidisciplinary and long lasting.Around the World, a big accent is placed on the use of methods and strategies of alternative communication methods (AAK for the persons with aphasia. Although the augmentative and the AAK methods for the persons with aphasia are relatively novel in the speech therapy, their applicability deserves an attention as well as the fact that they are promising new paths for researching.The master thesis is written on 104 pages, which include 35 tables and 48 graphics, as well as a glossary with 114 biographical units. The content is divided into introduction, grounding theory and methodology of research. The introduction shows the meaning and the necessity for research of alternative methods in the therapy and the treatment of persons with aphasia. The section with the theoretical grounds contains several mutually connected chapters (parts. In methodology of research section are described the subject of the research, the aim and the character of the research. Further the text contains the tasks, hypothesis, research variables, methods and techniques of the research, as well as the sample and the organization of the research. The end of the section consist the analysis and interpretation of the

76 FR 28301 - Reports, Forms, and Record Keeping Requirements

Science.gov (United States)

2011-05-16

... Regulations (section 106) Qualitative Research--Retailer Interviews. OMB Control Number: Not Assigned. Form... Respondents: 30. NHTSA will conduct two research phases. For the first phase, NHTSA will conduct two types of qualitative research. One research project will consist of two (2) focus groups in three (3) cities. Each...

Electrically assisted forming modeling and control

CERN Document Server

Salandro, Wesley A; Bunget, Cristina; Mears, Laine; Roth, John T

2015-01-01

Maximizing reader insights into the latest research findings and applications of Electrically-Assisted Forming (EAF) – whereby metals are formed under an electric current field – this book explains how such a process produces immediate improved formability of metals beyond the extent of thermal softening, and allows metals to be formed to greater elongation with lower mechanical energy as well as allowing for lightweight brittle metals such as magnesium and titanium to be formed without external heating or annealing, enabling the more effective use of these lightweight metals in design. Including case studies that illustrate and support the theoretical content and real-world applications of the techniques discussed, this book also serves to enrich readers understanding of the underlying theories that influence electro-plastic behaviour. The authors have extensive experience in studying Electrically-Assisted Forming and have written extensively on the topic with publications including experimental works, t...

Integrative genomic analysis identifies isoleucine and CodY as regulators of Listeria monocytogenes virulence.

Directory of Open Access Journals (Sweden)

Lior Lobel

2012-09-01

Full Text Available Intracellular bacterial pathogens are metabolically adapted to grow within mammalian cells. While these adaptations are fundamental to the ability to cause disease, we know little about the relationship between the pathogen's metabolism and virulence. Here we used an integrative Metabolic Analysis Tool that combines transcriptome data with genome-scale metabolic models to define the metabolic requirements of Listeria monocytogenes during infection. Twelve metabolic pathways were identified as differentially active during L. monocytogenes growth in macrophage cells. Intracellular replication requires de novo synthesis of histidine, arginine, purine, and branch chain amino acids (BCAAs, as well as catabolism of L-rhamnose and glycerol. The importance of each metabolic pathway during infection was confirmed by generation of gene knockout mutants in the respective pathways. Next, we investigated the association of these metabolic requirements in the regulation of L. monocytogenes virulence. Here we show that limiting BCAA concentrations, primarily isoleucine, results in robust induction of the master virulence activator gene, prfA, and the PrfA-regulated genes. This response was specific and required the nutrient responsive regulator CodY, which is known to bind isoleucine. Further analysis demonstrated that CodY is involved in prfA regulation, playing a role in prfA activation under limiting conditions of BCAAs. This study evidences an additional regulatory mechanism underlying L. monocytogenes virulence, placing CodY at the crossroads of metabolism and virulence.

Weighted-SNR-based fair scheduling for uplink OFDMA

KAUST Repository

Ma, Yao

2009-11-01

In this paper, we study the sum rate maximization algorithms with long-term proportional rate fairness (PRF) for uplink orthogonal frequency division multiple access (OFDMA) systems. In contrast to the rate-maximization schemes which used short-term PRF in the literature, we propose to use a selective multiuser diversity (SMuD) scheme to achieve a long-term PRF and improved sum rate performance. This scheme implements weighted channel signal-to-noise ratio (w-SNR)-based ranking for user selection on each subchannel, and then uses either water-filling (WF) or equal power allocation (EPA) along the assigned channels of each user. Both offline and online methods to find the optimal SNR weight factors are designed to achieve the target proportional rates for different users. The offline optimization technique requires to know the channel distribution information (CDI) at the scheduler. The online method uses the weight adaption combined with individual user rate tracking, which avoids the need to know the CDI. Analytical throughput metrics for the proposed w-SNR scheme with WF and EPA over Rayleigh channels are derived, and verified by simulations. Simulation results show that the proposed w-SNR PRF scheme can achieve significantly higher sum rates than the frequency diversity-based short-term and long-term fairness schemes. Besides the improved performance, the proposed schemes have a low complexity which is linear to numbers of users and subchannels.

Multisymplectic forms of degree three in dimension seven

Czech Academy of Sciences Publication Activity Database

Bureš, J.; Vanžura, Jiří

Suppl. 71, - (2003), s. 73-91 ISSN 0009-725X R&D Projects: GA ČR GA201/99/0675 Institutional research plan: CEZ:AV0Z1019905; CEZ:AV0Z1019905 Keywords : 3-form * multisymplectic form * group of automorphisms Subject RIV: BA - General Mathematics

Variation in standards of research compensation and child assent practices: a comparison of 69 institutional review board-approved informed permission and assent forms for 3 multicenter pediatric clinical trials.

Science.gov (United States)

Kimberly, Michael B; Hoehn, K Sarah; Feudtner, Chris; Nelson, Robert M; Schreiner, Mark

2006-05-01

To systematically compare standards for compensation and child participant assent in informed permission, assent, and consent forms (IP-A-CFs) approved by 55 local institutional review boards (IRBs) reviewing 3 standardized multicenter research protocols. Sixty-nine principal investigators participating in any of 3 national, multicenter clinical trials submitted standardized research protocols for their trials to their local IRBs for approval. Copies of the subsequently IRB-approved IP-A-CFs were then forwarded to an academic clinical research organization. This collection of IRB-approved forms allowed for a quasiexperimental retrospective evaluation of the variation in informed permission, assent, and consent standards operationalized by the local IRBs. Standards for compensation and child participant assent varied substantially across 69 IRB-approved IP-A-CFs. Among the 48 IP-A-CFs offering compensation, monetary compensation was offered by 33 as reimbursement for travel, parking, or food expenses, whereas monetary or material compensation was offered by 22 for subject inconvenience and by 13 for subject time. Compensation ranged widely within and across studies (study 1, $180-1425; study 2, $0-500; and study 3, $0-100). Regarding child participant assent, among the 57 IP-A-CFs that included a form of assent documentation, 33 included a line for assent on the informed permission or consent form, whereas 35 included a separate form written in simplified language. Of the IP-A-CFs that stipulated the documentation of assent, 31 specified > or =1 age ranges for obtaining assent. Informed permission or consent forms were addressed either to parents or child participants. In response to identical clinical trial protocols, local IRBs generate IP-A-CFs that vary considerably regarding compensation and child participant assent.

International Conference on Automorphic Forms and Number Theory

CERN Document Server

Al-Baali, Mehiddin; Ibukiyama, Tomoyoshi; Rupp, Florian

2014-01-01

This edited volume presents a collection of carefully refereed articles covering the latest advances in Automorphic Forms and Number Theory, that were primarily developed from presentations given at the 2012 “International Conference on Automorphic Forms and Number Theory,” held in Muscat, Sultanate of Oman. The present volume includes original research as well as some surveys and outlines of research altogether providing a contemporary snapshot on the latest activities in the field and covering the topics of: Borcherds products Congruences and Codes Jacobi forms Siegel and Hermitian modular forms Special values of L-series Recently, the Sultanate of Oman became a member of the International Mathematical Society. In view of this development, the conference provided the platform for scientific exchange and collaboration between scientists of different countries from all over the world. In particular, an opportunity was established for a close exchange between scientists and students of Germany, Oman, and J...

Innovative forming and fabrication technologies : new opportunities.

Energy Technology Data Exchange (ETDEWEB)

Davis, B.; Hryn, J.; Energy Systems; Kingston Process Metallurgy, Inc.

2008-01-31

The advent of light metal alloys and advanced materials (polymer, composites, etc.) have brought the possibility of achieving important energy reductions into the full life cycle of these materials, especially in transportation applications. 1 These materials have gained acceptance in the aerospace industry but use of light metal alloys needs to gain wider acceptance in other commercial transportation areas. Among the main reasons for the relatively low use of these materials are the lack of manufacturability, insufficient mechanical properties, and increased material costs due to processing inefficiencies. Considering the enormous potential energy savings associated with the use of light metal alloys and advanced materials in transportation, there is a need to identify R&D opportunities in the fields of materials fabrication and forming aimed at developing materials with high specific mechanical properties combined with energy efficient processes and good manufacturability. This report presents a literature review of the most recent developments in the areas of fabrication and metal forming focusing principally on aluminum alloys. In the first section of the document, the different sheet manufacturing technologies including direct chill (DC) casting and rolling, spray forming, spray rolling, thin slab, and strip casting are reviewed. The second section of the document presents recent research on advanced forming processes. The various forming processes reviewed are: superplastic forming, electromagnetic forming, age forming, warm forming, hydroforming, and incremental forming. Optimization of conventional forming processes is also discussed. Potentially interesting light metal alloys for high structural efficiency including aluminum-scandium, aluminum-lithium, magnesium, titanium, and amorphous metal alloys are also reviewed. This section concludes with a discussion on alloy development for manufacturability. The third section of the document reviews the latest

Children's Rights and Research Processes: Assisting Children to (In)formed Views

Science.gov (United States)

Lundy, Laura; McEvoy, Lesley

2012-01-01

Acknowledging children as rights-holders has significant implications for research processes. What is distinctive about a children's rights informed approach to research is a focus not only on safe, inclusive and engaging opportunities for children to express their views but also on deliberate strategies to assist children in the formation of…

Precision analysis in billet preparation for micro bulk metal forming

DEFF Research Database (Denmark)

Mahshid, Rasoul; Hansen, Hans N.

2015-01-01

The purpose of this research is to fabricate billets for an automated transfer press for micro forming. High performance transfer presses are wellknown in conventional metal forming and distinguished from their automation and mass production. The press used in this research is a vertical mechanical...... press. When using a vertical mechanical press, the material is fed as billets into the forming zone. Therefore, a large number of highly uniform billets are required to run mass production in such a setup. Shearing technique was used for manufacturing the billets. The efficiency of the shearing tool...

Researching Values in Education.

Science.gov (United States)

Halliday, John

2002-01-01

Considers methodological issues that arise when values form the main focus of empirical educational research. Includes discussion of the idea that social science, in general, and educational research, in particular, are forms of moral inquiry. Outlines a methodology of educational research, drawing from work by Imre Lakatos, Alasdair MacIntyre,…

Translation and cross-cultural adaptation of the Brazilian Portuguese version of the Driving Anger Scale (DAS: long form and short form

Directory of Open Access Journals (Sweden)

Jessye Almeida Cantini

2015-03-01

Full Text Available Introduction: Driving anger has attracted the attention of researchers in recent years because it may induce individuals to drive aggressively or adopt risk behaviors. The Driving Anger Scale (DAS was designed to evaluate the propensity of drivers to become angry or aggressive while driving. This study describes the cross-cultural adaptation of a Brazilian version of the short form and the long form of the DAS.Methods: Translation and adaptation were made in four steps: two translations and two back-translations carried out by independent evaluators; the development of a brief version by four bilingual experts in mental health and driving behaviors; a subsequent experimental application; and, finally, an investigation of operational equivalence.Results: Final Brazilian versions of the short form and of the long form of the DAS were made and are presented. Conclusions: This important instrument, which assesses driving anger and aggressive behaviors, is now available to evaluate the driving behaviors of the Brazilian population, which facilitates research in this field.

Fibrin network pattern changes of platelet-rich fibrin in young versus old age group of individuals: A cell block cytology study

OpenAIRE

Shravanthi Raghav Yajamanya; Anirban Chatterjee; Chaitanya Nischay Babu; Deepika Karunanithi

2016-01-01

Background: To evaluate variations in fibrin network patterns of the platelet-rich fibrin (PRF) in different age groups. Materials and Methods: Ninety-five patients were divided into three age groups: Group 1: (20?39 years); Group 2: (40?59 years); and Group 3: (60 years and above). PRF was prepared from blood samples of all patients and were subjected to cell block cytology method of histological analysis and slides were prepared to histologically assess the age-related changes in (i) fibrin...

Single Common Powertrain Lubricant (SCPL) Development. Part 2

Science.gov (United States)

2014-04-01

Lubricant (SCPL), General Engine Products (GEP) 6.5L(T), Detroit Diesel Corporation ( DDC ) 6V53T, High Temperature Oil Endurance, MIL-PRF-46167, MIL-PRF...using the Detroit Diesel Corporation ( DDC ) 6V53T, American Society for Testing and Materials (ASTM) D5966 roller follower wear protection...candidates. A Detroit Diesel Corporation ( DDC ) 6V53T, from the M113A3 Armored Personnel Carrier (APC), was used to evaluate the two revised candidates and a

Review of high-level waste form properties. [146 bibliographies

Energy Technology Data Exchange (ETDEWEB)

Rusin, J.M.

1980-12-01

This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several additional waste forms have enough promise to warrant continued research and development to bring their state of development up to that of glass and calcine. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer potential advantages and need further study. Although this report discusses waste form properties, the total waste management system should be considered in the final selection of a waste form option. Canister design, canister materials, overpacks, engineered barriers, and repository characteristics, as well as the waste form, affect the overall performance of a waste management system. These parameters were not considered in this comparison.

Families of automorphic forms and the trace formula

CERN Document Server

Shin, Sug; Templier, Nicolas

2016-01-01

Featuring the work of twenty-three internationally-recognized experts, this volume explores the trace formula, spectra of locally symmetric spaces, p-adic families, and other recent techniques from harmonic analysis and representation theory. Each peer-reviewed submission in this volume, based on the Simons Foundation symposium on families of automorphic forms and the trace formula held in Puerto Rico in January-February 2014, is the product of intensive research collaboration by the participants over the course of the seven-day workshop. The goal of each session in the symposium was to bring together researchers with diverse specialties in order to identify key difficulties as well as fruitful approaches being explored in the field. The respective themes were counting cohomological forms, p-adic trace formulas, Hecke fields, slopes of modular forms, and orbital integrals.

Teaching Grammar: The Use of The English Auxiliary "BE" Present Tense Verb among Malaysian Form 4 and Form 5 Students

Science.gov (United States)

Jishvithaa, Joanna M.; Tabitha, M.; Kalajahi, Seyed Ali Rezvani

2013-01-01

This research paper aims to explore the usage of the English Auxiliary "Be" Present Tense Verb, using corpus based method among Malaysian form 4 and form 5 students. This study is conducted by identifying and classifying the types of errors in the Auxiliary "Be" Present Tense verb in students' compositions from the MCSAW corpus…

NON-STANDARD FORMS OF EMPLOYMENT IN BUSINESS ORGANIZATIONS

Directory of Open Access Journals (Sweden)

A. E. Chekanov

2013-01-01

Full Text Available The article discusses the emergence and development of non-standard forms of employment and flexible working. The causes of their use reflects the results of research conducted in the workplace. Non-standard forms of employment and attractive today as they allow to expand the circle of the workforce.

SEPARATIONS AND WASTE FORMS CAMPAIGN IMPLEMENTATION PLAN

Energy Technology Data Exchange (ETDEWEB)

Vienna, John D.; Todd, Terry A.; Peterson, Mary E.

2012-11-26

This Separations and Waste Forms Campaign Implementation Plan provides summary level detail describing how the Campaign will achieve the objectives set-forth by the Fuel Cycle Reasearch and Development (FCRD) Program. This implementation plan will be maintained as a living document and will be updated as needed in response to changes or progress in separations and waste forms research and the FCRD Program priorities.

Management of an endo-perio lesion in an immature tooth using autologous platelet-rich fibrin: A case report

Directory of Open Access Journals (Sweden)

N B Nagaveni

2015-01-01

Full Text Available Treatment of an endo-perio lesion involving a non-vital young permanent tooth is a highly challenging task to Pediatric Dentists. There is a quest for the newer biological approach to management of these lesions as traditional methods have various disadvantages. Recently, platelet-rich fibrin (PRF, a second-generation platelet concentrate, is rich in growth factors have been used in the periodontal regeneration procedure. The purpose of this paper is to describe the efficacy of PRF in the treatment of a deep intra bony defect associated with an endo-perio lesion in an immature right mandibular first premolar of 12-year-old female patient. A freshly prepared autologous PRF membrane was placed in the bony defect following debridement. Clinical and radiographic follow-up were performed at regular intervals that revealed absence of pain, gain in clinical attachment level, reduction in probing depth, and excellent bone regeneration indicating successful outcome.

Autologus Platelet Rich Fibrin aided Revascularization of an immature, non-vital permanent tooth with apical periodontitis: A case report.

Science.gov (United States)

Jadhav, Ganesh Ranganath; Shah, Dipali; Raghvendra, Srinidhi Surya

2015-01-01

Caries or trauma induced non-vital immature permanent tooth with blunderbuss, thin root which are very common among childrens are corrected using regenerative endodontic (revascularization) procedures. In the presented case, a 16-year-old boy reported with chief complaint of pain in maxillary left central incisor (Tooth #21). Tooth #21 showed grade III mobility, draining labial sinus, and short blunderbuss root with diffuse periapical radiolucency. Patient was explained the treatment plan and written informed consent was taken. Platelet rich fibrin (PRF) was prepared according to standard protocol. Autologous PRF was carried to the apical portion of the root canal after inducing revascularization. Access opening was double sealed with MTA and resin modified glass ionomer cement (RMGI). Baseline, 12 month and 18 month follow-up intraoral radiographs were taken. Clinically case was asymptomatic with complete resolution of intraoral sinus. Periapical healing, apical closure, root lengthening and dentinal wall thickening were uneventful. Thus PRF supplementation hastens the predictability and rate of revascularization in non-vital immature permanent teeth.

LD-pumped actively Q-switched c-cut Nd:GdVO4 self-Raman laser operating at 1166 and 1176 nm

Science.gov (United States)

Sun, Xinzhi; Zhang, Xihe; Li, Shutao; Dong, Yuan

2017-12-01

A laser diode pumped actively Q-switched c-cut Nd:GdVO4 self-Raman laser is experimentally investigated. Simultaneous pulse outputs at 1166 nm and 1176 nm corresponding to the Raman shifts of 807 and 882 cm-1 are acquired. At the pulse repetition frequency (PRF) of 20 kHz, the maximum output power is 103 mW at 1166 nm with the incident pump power of 2.31 W, while 1176 nm output power reaches 530 mW with the incident pump power of 4.11 W. The maximum output power of Raman laser is 570 mW with the incident pump power of 4.11 W and the PRF of 30 kHz. With the incident pump power of 3.67 W and the PRF of 30 kHz, the highest diode-to-Stokes optical conversion efficiency of 14.9% is obtained with the corresponding average output power of 547 mW.

Platelet-Rich Fibrin with β-Tricalcium Phosphate—A Noval Approach for Bone Augmentation in Chronic Periapical Lesion: A Case Report

Directory of Open Access Journals (Sweden)

K. B. Jayalakshmi

2012-01-01

Full Text Available Introduction. This paper describes a case of bone augmentation with combination of Platelet-Rich Fibrin (PRF and β-TCP for treatment of chronic periapical cyst. The case was followed for 12 months. Methods. Patient presented with chronic periapical lesion in maxillary anterior teeth with history of trauma 8 years back. Radiographically, a periapical cyst was seen in relation to maxillary left central and lateral incisors. Conventional endodontic treatment was started. Since it was not successful, apical surgery was performed. Bone augmentation was done using PRF in combination with β-TCP bone graft to achieve faster healing of the periapical region. Regular followups at 3, 6, 9, and 12 months were done. Results. Healing was uneventful. Follow-up examinations revealed progressive, significant, and predictable clinical and radiographic bone regeneration/healing without any clinical symptoms. Conclusions. Combined use of PRF and β-TCP for bone augmentation in treatment of periapical defects is a potential treatment alternative for faster healing than using these biomaterials alone.

New directions in Dirichlet forms

CERN Document Server

Jost, Jürgen; Mosco, Umberto; Rockner, Michael; Sturm, Karl-Theodor

1998-01-01

The theory of Dirichlet forms brings together methods and insights from the calculus of variations, stochastic analysis, partial differential and difference equations, potential theory, Riemannian geometry and more. This book features contributions by leading experts and provides up-to-date, authoritative accounts on exciting developments in the field and on new research perspectives. Topics covered include the following: stochastic analysis on configuration spaces, specifically a mathematically rigorous approach to the stochastic dynamics of Gibbs measures and infinite interacting particle systems; subelliptic PDE, homogenization, and fractals; geometric aspects of Dirichlet forms on metric spaces and function theory on such spaces; generalized harmonic maps as nonlinear analogues of Dirichlet forms, with an emphasis on non-locally compact situations; and a stochastic approach based on Brownian motion to harmonic maps and their regularity. Various new connections between the topics are featured, and it is de...

Designing Effective Web Forms for Older Web Users

Science.gov (United States)

Li, Hui; Rau, Pei-Luen Patrick; Fujimura, Kaori; Gao, Qin; Wang, Lin

2012-01-01

This research aims to provide insight for web form design for older users. The effects of task complexity and information structure of web forms on older users' performance were examined. Forty-eight older participants with abundant computer and web experience were recruited. The results showed significant differences in task time and error rate…

Densified waste form and method for forming

Science.gov (United States)

Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

2015-08-25

Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

Integration of adaptive process control with computational simulation for spin-forming

International Nuclear Information System (INIS)

Raboin, P. J. LLNL

1998-01-01

Improvements in spin-forming capabilities through upgrades to a metrology and machine control system and advances in numerical simulation techniques were studied in a two year project funded by Laboratory Directed Research and Development (LDRD) at Lawrence Livermore National Laboratory. Numerical analyses were benchmarked with spin-forming experiments and computational speeds increased sufficiently to now permit actual part forming simulations. Extensive modeling activities examined the simulation speeds and capabilities of several metal forming computer codes for modeling flat plate and cylindrical spin-forming geometries. Shape memory research created the first numerical model to describe this highly unusual deformation behavior in Uranium alloys. A spin-forming metrology assessment led to sensor and data acquisition improvements that will facilitate future process accuracy enhancements, such as a metrology frame. Finally, software improvements (SmartCAM) to the manufacturing process numerically integrate the part models to the spin-forming process and to computational simulations

Difference-theoretical Analysis of Aesthetic Media and Forms

Directory of Open Access Journals (Sweden)

Franz Kasper Krönig

2018-04-01

Full Text Available The general medium/form-difference-theory as proposed by Fritz Heider (cf. Heider, 1959 has been seized on by the sociological systems theory as an epistemological and heuristic basis of such a generality that it can be applied to virtually all conceivable fields of research. One could arguably speak of a new paradigm that overcomes traditional differences such as subject/object and cause/effect. This approach has been applied to all types of art, and various research questions in the fields of aesthetics and art theory. This paper proposes a differentiation and categorisation of aesthetic media and forms in order to lay the groundwork for art criticism on a third way between subjective appreciation and objective reasoning. Musical examples demonstrate the applicability of the medium/form-difference-theoretical approach for the aesthetics of music and music criticism.

An Evaluation of the Accuracy of the Subtraction Method Used for Determining Platelet Counts in Advanced Platelet-Rich Fibrin and Concentrated Growth Factor Preparations

Directory of Open Access Journals (Sweden)

Taisuke Watanabe

2017-01-01

Full Text Available Platelet concentrates should be quality-assured of purity and identity prior to clinical use. Unlike for the liquid form of platelet-rich plasma, platelet counts cannot be directly determined in solid fibrin clots and are instead calculated by subtracting the counts in other liquid or semi-clotted fractions from those in whole blood samples. Having long suspected the validity of this method, we herein examined the possible loss of platelets in the preparation process. Blood samples collected from healthy male donors were immediately centrifuged for advanced platelet-rich fibrin (A-PRF and concentrated growth factors (CGF according to recommended centrifugal protocols. Blood cells in liquid and semi-clotted fractions were directly counted. Platelets aggregated on clot surfaces were observed by scanning electron microscopy. A higher centrifugal force increased the numbers of platelets and platelet aggregates in the liquid red blood cell fraction and the semi-clotted red thrombus in the presence and absence of the anticoagulant, respectively. Nevertheless, the calculated platelet counts in A-PRF/CGF preparations were much higher than expected, rendering the currently accepted subtraction method inaccurate for determining platelet counts in fibrin clots. To ensure the quality of solid types of platelet concentrates chairside in a timely manner, a simple and accurate platelet-counting method should be developed immediately.

Iodine waste form summary report (FY 2007)

International Nuclear Information System (INIS)

Krumhansl, James Lee; Nenoff, Tina Maria; McMahon, Kevin A.; Gao, Huizhen; Rajan, Ashwath Natech

2007-01-01

This new program at Sandia is focused on Iodine waste form development for GNEP cycle needs. Our research has a general theme of 'Waste Forms by Design' in which we are focused on silver loaded zeolite waste forms and related metal loaded zeolites that can be validated for chosen GNEP cycle designs. With that theme, we are interested in materials flexibility for iodine feed stream and sequestration material (in a sense, the ability to develop a universal material independent on the waste stream composition). We also are designing the flexibility to work in a variety of repository or storage scenarios. This is possible by studying the structure/property relationship of existing waste forms and optimizing them to our current needs. Furthermore, by understanding the properties of the waste and the storage forms we may be able to predict their long-term behavior and stability. Finally, we are working collaboratively with the Waste Form Development Campaign to ensure materials durability and stability testing

Variations of bubble cavitation and temperature elevation during lesion formation by high-intensity focused ultrasound.

Science.gov (United States)

Zhou, Yufeng; Gao, Xiaobin Wilson

2013-08-01

High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in both thermal ablations for solid tumor/cancer and soft-tissue fragmentation. Mechanical and thermal effects, which play an important role in the HIFU treatment simultaneously, are dependent on the operating parameters and may vary with the progress of therapy. Mechanical erosion in the shape of a "squid," a "dumbbell" lesion with both mechanical and thermal lesions, or a "tadpole" lesion with mechanical erosion at the center and thermal necrosis on the boundary in the transparent gel phantom could be produced correspondingly with the pulse duration of 5-30 ms, which is much longer than histotripsy burst but shorter than the time for tissue boiling, and pulse repetition frequency (PRF) of 0.2-5 Hz. Meanwhile, variations of bubble cavitation (both inertial and stable cavitation) and temperature elevation in the focal region (i.e., z = -2.5, 0, and 2.5 mm) were measured by passive cavitation detection (PCD) and thermocouples during the therapeutic procedure, respectively. Stable cavitation increased with the pulse duration, PRF, and the number of pulses delivered. However, inertial cavitation was found to increase initially and then decrease with long pulse duration and high PRF. Temperature in the pre-focal region is always higher than those at the focal and post-focal position in all tests. Great variations of PCD signals and temperature elevation are due to the generation and persistence of large bubble, which is resistant to collapse and occurs with the increase of pulse duration and PRF. Similar lesion pattern and variations were also observed in ex vivo porcine kidneys. Hyperechoes in the B-mode ultrasound image were comparable to the shape and size of lesions in the dissected tissue. Thermal lesion volume increased with the increase of pulse duration and PRF, but mechanical erosion reached its maximum volume with the pulse duration of 20 ms and PRF of 1�

Focus on Form in task-based language teaching

NARCIS (Netherlands)

van de Guchte, M.

2015-01-01

This dissertation presents research on the way in which learners focus on grammar in task-based language teaching (TBLT). Such a focus on grammar during meaningful task performance is called a Focus on Form (FonF). For this PhD research project we conducted three experimental studies which

Research Note--Should Consumers Use the Halo to Form Product Evaluations?

OpenAIRE

Peter Boatwright; Ajay Kalra; Wei Zhang

2008-01-01

In purchase situations where attribute information is either missing or difficult to judge, a well-known heuristic that consumers use to form evaluations is the halo effect. The psychology literature has widely considered the halo a reflection of consumers' inability to discriminate between different attributes and have therefore labeled it the "halo error" or the "logical error." The objective of this paper is to offer a rationale for the halo effect. We use a decision-theory framework to sh...

Mixed low-level waste form evaluation

International Nuclear Information System (INIS)

Pohl, P.I.; Cheng, Wu-Ching; Wheeler, T.; Waters, R.D.

1997-01-01

A scoping level evaluation of polyethylene encapsulation and vitreous waste forms for safe storage of mixed low-level waste was performed. Maximum permissible radionuclide concentrations were estimated for 15 indicator radionuclides disposed of at the Hanford and Savannah River sites with respect to protection of the groundwater and inadvertent intruder pathways. Nominal performance improvements of polyethylene and glass waste forms relative to grout are reported. These improvements in maximum permissible radionuclide concentrations depend strongly on the radionuclide of concern and pathway. Recommendations for future research include improving the current understanding of the performance of polymer waste forms, particularly macroencapsulation. To provide context to these estimates, the concentrations of radionuclides in treated DOE waste should be compared with the results of this study to determine required performance

Platelet rich fibrin combined with decalcified freeze-dried bone allograft for the treatment of human intrabony periodontal defects: a randomized split mouth clinical trail.

Science.gov (United States)

Agarwal, Ashish; Gupta, Narinder Dev; Jain, Avikal

2016-01-01

Polypeptide growth factors of platelet rich fibrin (PRF) have the potential to regenerate periodontal tissues. Osteoinductive property of demineralized freeze-dried bone allograft (DFDBA) has been successfully utilized in periodontal regeneration. The aim of the present randomized, split mouth, clinical trial was to determine the additive effects of PRF with a DFDBA in the treatment of human intrabony periodontal defects. Sixty interproximal infrabony defects in 30 healthy, non-smoker patients diagnosed with chronic periodontitis were randomly assigned to PRF/DFDBA group or the DFDBA/saline. Clinical [pocket depth (PD), clinical attachment level (CAL) and gingival recession (REC)] and radiographic (bone fill, defect resolution and alveolar crest resorption) measurements were made at baseline and at a 12-month evaluation. Compared with baseline, 12-month results indicated that both treatment modalities resulted in significant changes in all clinical and radiographic parameters. However, the PRP/DFDBA group exhibited statistically significantly greater changes compared with the DFDBA/saline group in PD (4.15 ± 0.84 vs 3.60 ± 0.51 mm), CAL (3.73 ± 0.74 vs 2.61 ± 0.68 mm), REC (0.47 ± 0.56 vs 1.00 ± 0.61 mm), bone fill (3.50 ± 0.67 vs 2.49 ± 0.64 mm) and defect resolution (3.73 ± 0.63 vs 2.75 ± 0.57 mm). Observations indicate that a combination of PRF and DFDBA is more effective than DFDBA with saline for the treatment of infrabony periodontal defects.

Effects of platelet-rich fibrin on healing of intra-bony defects treated with anorganic bovine bone mineral.

Science.gov (United States)

Sezgin, Yasemin; Uraz, Ahu; Taner, I Levent; Çulhaoğlu, Rana

2017-01-26

Anorganic bovine bone mineral (ABBM) is extensively used in the treatment of intra-bony defects. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with a simplified technique. Although certain studies have reported the use of PRF in the treatment of intra-bony defects, to date, none of them have evaluated its additive effects with ABBM. Therefore, a randomised, split-mouth clinical trial was conducted to compare healing of intra-bony defects treated with an ABBM-PRF combination with healing of those treated with ABBM alone. By using a split-mouth design, 15 paired intra-bony defects were randomly treated with either ABBM alone (control group) or ABBM-PRF combination (test group). Following clinical parameters and radiographical measurements were recorded at baseline and 6 months after treatment: plaque index (PI), gingival index (GI), probing depth (PD), gingival recession (GR), clinical attachment level (CAL), vertical bone loss, depth of defect and defect angle. Preoperative clinical and radiographical measurements were similar for the test and control groups. Statistically significant reductions in GI, PD, CAL, vertical bone loss, depth of intra-bony defect and widening of defect angle were detected after treatment in both groups. With respect to inter-group analysis, gain in CAL was significantly greater in the test group than in the control group, whereas no inter-group differences were observed in any other parameter. The results of this study indicate that both therapies are effective in the treatment of intra-bony defects.

Adjunctive Effect of Autologus Platelet-Rich Fibrin to Barrier Membrane in the Treatment of Periodontal Intrabony Defects.

Science.gov (United States)

Panda, Saurav; Sankari, Malaiappan; Satpathy, Anurag; Jayakumar, Doraiswamy; Mozzati, Marco; Mortellaro, Carmen; Gallesio, Giorgia; Taschieri, Silvio; Del Fabbro, Massimo

2016-05-01

Autologous platelet-rich fibrin (PRF) and barrier membranes in the treatment of intrabony defects in chronic periodontitis patients have shown significant clinical benefits. This study evaluates the additive effect of autologous PRF in combination with a barrier membrane versus the use of barrier membrane alone for the treatment of intrabony defects in chronic periodontitis patients. A randomized split-mouth design was used. Sixteen patients with 32 paired intrabony defects were included. In each patient 1 defect was treated using a resorbable collagen membrane along with PRF (test group) and the other defect by guided tissue regeneration alone (control group). The following clinical parameters were measured at baseline and after 9 months: plaque index, modified sulcus bleeding index, probing pocket depth, clinical attachment level, and gingival marginal level. The radiographic defect depth was also assessed at baseline and after 9 months. Test group showed a statistically significant improvement for probing depth (P = 0.002), clinical attachment level (P = 0.001), and radiographic defect depth (P < 0.001) after 9 months as compared with the control sites. Radiographic defect depth reduction was 58.19 ± 13.24% in the test group as compared with 24.86 ± 9.94% reduction in the control group. The adjunctive use of PRF in combination with barrier membrane is more effective in the treatment of intrabony defects in chronic periodontitis as compared with barrier membrane alone.

Effect of carbonated hydroxyapatite incorporated advanced platelet rich fibrin intrasulcular injection on the alkaline phosphatase level during orthodontic relapse

Science.gov (United States)

Alhasyimi, Ananto Ali; Pudyani, Pinandi Sri; Asmara, Widya; Ana, Ika Dewi

2018-02-01

Nowadays, relapse in orthodontic treatment is considered very important because of high incidence of relapse after the treatment. Alkaline phosphatase (ALP) as a biomarker of bone formation will decrease in compression sites during relapse after orthodontic tooth movement. In this situation, manipulating alveolar bone remodeling to increase ALP level is considered one of the new strategies to prevent relapse properly. In the field of tissue engineering, in this study, carbonated hydroxyapatite (CHA) is expected to have the ability to incorporate advanced platelet rich fibrin (aPRF). Next, CHA will retain the aPRF containing various growth factors (GF) until it reaches into a specific targeted area, gradually degraded, and deliver the GF in a controlled manner to prevent relapse. Here, gingival crevicular fluid (GCF) of 45 samples (n=45) were collected and levels of ALP were analyzed using UV-Vis 6300 Spectrophotometer at 405 nm wavelength. We found that there is a significant difference of ALP levels (p<0.05) in GCF between treatments and control groups. ALP level was elevated significantly in CHA and CHA-aPRF groups at days 7 and 14 after debonding compared with the control groups. The peak level of ALP was observed at days 14 after debonding in groups C (0.789 ± 0.039 U/mg). Therefore, it can be concluded that the application of hydrogel CHA with controlled release manner incorporated aPRF enhances bone regeneration by increasing ALP level.

Foucault's Notion of Forms of Problematization

DEFF Research Database (Denmark)

Frederiksen, Kirsten; Lomborg, Kirsten; Beedholm, Kirsten

2015-01-01

's later writings and his diagnosis of his own work as studies of forms of problematization. To shed light on the possibilities that this approach offers to the researcher, we present a reading of aspects of Foucault's work, with a focus on his notion of forms of problematization. Furthermore, we elaborate......'s oeuvre, we argue against this critique and provide a methodological discussion of the perception that Foucault's method constitutes, primarily, discourse analysis. We argue that it is possible to overcome this critique of Foucault's work by the application of methodological tools adapted from Foucault...

Forme di vita e relazione educativa

Directory of Open Access Journals (Sweden)

Viviana Segreto

2015-05-01

Full Text Available The aim of this paper is to show that the main object of pedagogical research is relationship among people who share the same context. The analysis follows a linguistic approach, from a theoretical and metaphysical kind of language to a language of forms of life. After the linguistic turn, particularly in Ludwig Wittgenstein, forsaking a Platonic language means throwing language in forms of life, and blending it with people and their lives. So an educational process has to leave the unique, traditional pattern to open itself to different voices of life.

New Challenges to the automotive fasteners and cold formed parts in the chinese markets

Directory of Open Access Journals (Sweden)

Chen Jin Guang

2015-01-01

Full Text Available Despite of substantial cold forming related R&D, innovations and new inventions have been achieved and reported by research institutes and famous industrial organisations, many small and medium size enterprises in the third world or developing countries considering this R&D activities is too luxury. Most of the third world cold forming factories still dependent on previously successful experiences by using trial an error methods. The author does not make attempt to write a scientific research paper on metal forming processes but, instead, to report the effect, application and impact of the previous and on-going metal forming related research work to the cold forming industry in China. This paper highlights the effect of 1 efficient manufacturing practices, 2 upgrading in process technology and 3improved machines capabilities in upgrading the cold forming operation. Three real-life cold forming examples from Ritai are illustrated showing the transformation from an automotive fasteners maker into a cold formed parts manufacturer.

Block Pickard Models for Two-Dimensional Constraints

DEFF Research Database (Denmark)

Forchhammer, Søren; Justesen, Jørn

2009-01-01

In Pickard random fields (PRF), the probabilities of finite configurations and the entropy of the field can be calculated explicitly, but only very simple structures can be incorporated into such a field. Given two Markov chains describing a boundary, an algorithm is presented which determines...... for the domino tiling constraint represented by a quaternary alphabet. PRF models are also presented for higher order constraints, including the no isolated bits (n.i.b.) constraint, and a minimum distance 3 constraint by defining super symbols on blocks of binary symbols....

Germline cytotoxic lymphocytes defective mutations in Chinese patients with lymphoma

OpenAIRE

Chen, Xue; Zhang, Yang; Wang, Fang; Wang, Mangju; Teng, Wen; Lin, Yuehui; Han, Xiangping; Jin, Fangyuan; Xu, Yuanli; Cao, Panxiang; Fang, Jiancheng; Zhu, Ping; Tong, Chunrong; Liu, Hongxing

2017-01-01

Certain patients with lymphoma may harbor mutations in perforin 1 (PRF1), unc-13 homolog D (UNC13D), syntaxin 11 (STX11), STXBP2 (syntaxin binding protein 2) or SH2 domain containing 1A (SH2D1A), which causes functional defects of cytotoxic lymphocytes. Data regarding the association between genetic defects and the development of lymphoma in Chinese patients are limited to date. In the present study, 90 patients with lymphoma were analyzed for UNC13D, PRF1, STXBP2, STX11, SH2D1A and X-linked ...

Research organizations

DEFF Research Database (Denmark)

Larsen, Bøje; Aagaard, Peter

in Copenhagen - we argue that a post-rational form of research activity is emerging which revert these features. We term this new type of research "enchanted research", "sciencetainment" and "Mode2-b research". The factors that facilitate this development include the boring style of conventional research......, growing competition for research funds, more project funding compared to institutional funding and a demand for accountability. Countervailing forces also exist, however....

Tribo-systems for Sheet Metal Forming

DEFF Research Database (Denmark)

Bay, Niels

2009-01-01

The present paper gives an overview of more than 10 years work by the author’s research group through participation in national as well as international framework programmes on developing and testing environmentally friendly lubricants and tool materials and coatings inhibiting galling. Partners ......’s research group has especially been involved in the development of a system of tribo-tests for sheet metal forming and in testing and modelling of friction and limits of lubrication of new, environmentally friendly lubricants and tool materials....

Problems in the theory of modular forms

CERN Document Server

Murty, M Ram; Graves, Hester

2016-01-01

This book introduces the reader to the fascinating world of modular forms through a problem-solving approach. As such, besides researchers, the book can be used by the undergraduate and graduate students for self-instruction. The topics covered include q-series, the modular group, the upper half-plane, modular forms of level one and higher level, the Ramanujan τ-function, the Petersson inner product, Hecke operators, Dirichlet series attached to modular forms and further special topics. It can be viewed as a gentle introduction for a deeper study of the subject. Thus, it is ideal for non-experts seeking an entry into the field. .

Decolonizing Qualitative Research: Non-traditional Reporting Forms in the Academy

Directory of Open Access Journals (Sweden)

Elsa M. González y González

2006-09-01

Full Text Available Qualitative researchers have assumed that cross-cultural work required deep understanding of the culture being reported on. Even earlier, cross-cultural work focused on "receiving contexts," and on end-users who were primarily Western. The utility of such studies is severely limited, however, in a globalized world, and studies undertaken now must serve the interests of not only Western scholars, but also the needs of nationals and locals (or indigenous peoples. Research conducted in different languages, non-Western contexts and different cultures becomes more problematic and understanding intrinsic issues more urgent with the increasing number of reports (such as dissertations conducted by international scholars and thus bear potential for decolonizing the academy. Conducting and reporting cross-cultural qualitative data focuses on understanding at least five major ideas: working with bilingual data, considering non-Western cultural traditions, multiple perspectives, multi-vocal & multi-lingual texts, and technical issues to insure accessibility. URN: urn:nbn:de:0114-fqs060418

Social and Communicative Functions of Informed Consent Forms in East Asia and Beyond

Directory of Open Access Journals (Sweden)

Go Yoshizawa

2017-07-01

Full Text Available The recent research and technology development in medical genomics has raised new issues that are profoundly different from those encountered in traditional clinical research for which informed consent was developed. Global initiatives for international collaboration and public participation in genomics research now face an increasing demand for new forms of informed consent which reflect local contexts. This article analyzes informed consent forms (ICFs for genomic research formulated by four selected research programs and institutes in East Asia – the Medical Genome Science Program in Japan, Universiti Sains Malaysia Human Research Ethics Committee in Malaysia, and the Taiwan Biobank and the Taipei Medical University- Joint Institutional Review Board in Taiwan. The comparative text analysis highlights East Asian contexts as distinct from other regions by identifying communicative and social functions of consent forms. The communicative functions include re-contact options and offering interactive support for research participants, and setting opportunities for family or community engagement in the consent process. This implies that informed consent cannot be validated solely with the completion of a consent form at the initial stage of the research, and informed consent templates can facilitate interactions between researchers and participants through (even before and after the research process. The social functions consist of informing participants of possible social risks that include genetic discrimination, sample and data sharing, and highlighting the role of ethics committees. Although international ethics harmonization and the subsequent coordination of consent forms may be necessary to maintain the quality and consistency of consent process for data-intensive international research, it is also worth paying more attention to the local values and different settings that exist where research participants are situated for research in

Social and Communicative Functions of Informed Consent Forms in East Asia and Beyond.

Science.gov (United States)

Yoshizawa, Go; Sasongko, Teguh H; Ho, Chih-Hsing; Kato, Kazuto

2017-01-01

The recent research and technology development in medical genomics has raised new issues that are profoundly different from those encountered in traditional clinical research for which informed consent was developed. Global initiatives for international collaboration and public participation in genomics research now face an increasing demand for new forms of informed consent which reflect local contexts. This article analyzes informed consent forms (ICFs) for genomic research formulated by four selected research programs and institutes in East Asia - the Medical Genome Science Program in Japan, Universiti Sains Malaysia Human Research Ethics Committee in Malaysia, and the Taiwan Biobank and the Taipei Medical University- Joint Institutional Review Board in Taiwan. The comparative text analysis highlights East Asian contexts as distinct from other regions by identifying communicative and social functions of consent forms. The communicative functions include re-contact options and offering interactive support for research participants, and setting opportunities for family or community engagement in the consent process. This implies that informed consent cannot be validated solely with the completion of a consent form at the initial stage of the research, and informed consent templates can facilitate interactions between researchers and participants through (even before and after) the research process. The social functions consist of informing participants of possible social risks that include genetic discrimination, sample and data sharing, and highlighting the role of ethics committees. Although international ethics harmonization and the subsequent coordination of consent forms may be necessary to maintain the quality and consistency of consent process for data-intensive international research, it is also worth paying more attention to the local values and different settings that exist where research participants are situated for research in medical genomics. More

Harmonic Maass forms and mock modular forms

CERN Document Server

Bringmann, Kathrin; Ono, Ken

2017-01-01

Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.

Forms and terminology of Direct Democracy

DEFF Research Database (Denmark)

Svensson, Palle

It is apparent that some confusion exits both among researchers and political actors about the various forms of direct democracy. Various institutions such as IRI and IDEA, various countries such as Switzerland and California, and various authors such as Pier Vincenzo Uleri and David Altman present...

Pulsed Radiofrequency Applied to the Sciatic Nerve Improves Neuropathic Pain by Down-regulating The Expression of Calcitonin Gene-related Peptide in the Dorsal Root Ganglion

Science.gov (United States)

Ren, Hao; Jin, Hailong; Jia, Zipu; Ji, Nan; Luo, Fang

2018-01-01

Background: Clinical studies have shown that applying pulsed radiofrequency (PRF) to the neural stem could relieve neuropathic pain (NP), albeit through an unclear analgesic mechanism. And animal experiments have indicated that calcitonin gene-related peptide (CGRP) expressed in the dorsal root ganglion (DRG) is involved in generating and maintaining NP. In this case, it is uncertain whether PRF plays an analgesic role by affecting CGRP expression in DRG. Methods: Rats were randomly divided into four groups: Groups A, B, C, and D. In Groups C and D, the right sciatic nerve was ligated to establish the CCI model, while in Groups A and B, the sciatic nerve was isolated without ligation. After 14 days, the right sciatic nerve in Groups B and D re-exposed and was treated with PRF on the ligation site. Thermal withdrawal latency (TWL) and hindpaw withdrawal threshold (HWT) were measured before PRF treatment (Day 0) as well as after 2, 4, 8, and 14 days of treatment. At the same time points of the behavioral tests, the right L4-L6 DRG was sampled and analyzed for CGRP expression using RT-qPCR and an enzyme-linked immunosorbent assay (ELISA). Results: Fourteen days after sciatic nerve ligation, rats in Groups C and D had a shortened TWL (P 0.05). On the 8th and 14th days, the mRNA levels in Group D were restored to those of Groups A and B. Meanwhile, the CGRP content of Group D gradually dropped over time, from 76.4 pg/mg (Day 0) to 57.5 pg/mg (Day 14). Conclusions: In this study, we found that, after sciatic nerve ligation, rats exhibited apparent hyperalgesia and allodynia, and CGRP mRNA and CGRP contents in the L4-L6 DRG increased significantly. Through lowering CGRP expression in the DRG, PRF treatment might relieve the pain behaviors of NP. PMID:29333099

Antitumor effects of vitamins K1, K2 and K3 on hepatocellular carcinoma in vitro and in vivo.

Science.gov (United States)

Hitomi, Misuzu; Yokoyama, Fumi; Kita, Yuko; Nonomura, Takako; Masaki, Tsutomu; Yoshiji, Hitoshi; Inoue, Hideyuki; Kinekawa, Fumihiko; Kurokohchi, Kazutaka; Uchida, Naohito; Watanabe, Seishiro; Kuriyama, Shigeki

2005-03-01

A number of studies have shown that various K vitamins, specifically vitamins K2 and K3, possess antitumor activity on various types of rodent- and human-derived neoplastic cell lines. In the present study, we examined the antitumor effects of vitamins K1, K2 and K3 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of these vitamins in vitro and in vivo. Although vitamin K1 did not inhibit proliferation of PLC/PRF/5 cells at a 90-microM concentration (the highest tested), vitamins K2 and K3 suppressed proliferation of the cells at concentrations of 90 and 9 microM, respectively. By flow cytometric analysis, it was shown that not only vitamin K1, but also vitamin K2 did not induce apoptosis or cell cycle arrest on PLC/PRF/5 cells. In contrast, vitamin K3 induced G1 arrest, but not apoptosis on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that both vitamins K2 and K3 markedly suppressed the growth of HCC tumors to similar extent. Protein expression of cyclin D1 and cyclin-dependent kinase 4 (Cdk4), but not p16INK4a Cdk inhibitor in the tumor was significantly reduced by vitamin K2 or K3 treatment, indicating that vitamins K2 and K3 may induce G1 arrest of cell cycle on PLC/PRF/5 cells in vivo. Taken collectively, vitamins K2 and K3 were able to induce potent antitumor effects on HCC in vitro and in vivo, at least in part, by inducing G1 arrest of the cell cycle. The results indicate that vitamins K2 and K3 may be useful agents for the treatment of patients with HCC.

Removal of residual cavitation nuclei to enhance histotripsy fractionation of soft tissue.

Science.gov (United States)

Duryea, Alexander P; Cain, Charles A; Roberts, William W; Hall, Timothy L

2015-12-01

Remanent bubble nuclei generated by primary cavitation collapse can limit the efficiency of histotripsy softtissue fractionation. When these residual bubbles persist from one histotripsy pulse to the next, they can seed the repetitive nucleation of cavitation bubbles at a discrete set of sites within the focal volume. This effect-referred to as cavitation memory- manifests in inefficient lesion formation, because certain sites within the focal volume are overtreated whereas others remain undertreated. Although the cavitation memory effect can be passively mitigated by using a low pulse repetition frequency (PRF) that affords remanent nuclei sufficient time for dissolution between successive pulses, this low PRF also results in slow lesion production. As such, it would be highly desirable to maintain the high per-pulse efficiency associated with low pulse rates when much higher PRFs are utilized. In this vein, we have developed a strategy for the active removal of the remanent bubble nuclei following primary cavitation collapse, using low-amplitude ultrasound sequences (termed bubble-removal sequences) to stimulate the aggregation and subsequent coalescence of these bubbles. In this study, bubbleremoval sequences were incorporated in high-PRF histotripsy treatment (100 Hz) of a red blood cell tissue-mimicking phantom that allows for the visualization of lesion development in real time. A series of reference treatments were also conducted at the low PRF of 1 Hz to provide a point of comparison for which cavitation memory effects are minimal. It was found that bubble-removal sequences as short as 1 ms are capable of maintaining the efficacious lesion development characteristics associated with the low PRF of 1 Hz when the much higher pulse rate of 100 Hz is used. These results were then extended to the treatment of a large volume within the tissue phantom, and optimal bubble-removal sequences identified for the singlefocal- spot case were utilized to homogenize a 10 �

A second-order orientation-contrast stimulus for population-receptive-field-based retinotopic mapping.

Science.gov (United States)

Yildirim, Funda; Carvalho, Joana; Cornelissen, Frans W

2018-01-01

Visual field or retinotopic mapping is one of the most frequently used paradigms in fMRI. It uses activity evoked by position-varying high luminance contrast visual patterns presented throughout the visual field for determining the spatial organization of cortical visual areas. While the advantage of using high luminance contrast is that it tends to drive a wide range of neural populations - thus resulting in high signal-to-noise BOLD responses - this may also be a limitation, especially for approaches that attempt to squeeze more information out of the BOLD response, such as population receptive field (pRF) mapping. In that case, more selective stimulation of a subset of neurons - despite reduced signals - could result in better characterization of pRF properties. Here, we used a second-order stimulus based on local differences in orientation texture - to which we refer as orientation contrast - to perform retinotopic mapping. Participants in our experiment viewed arrays of Gabor patches composed of a foreground (a bar) and a background. These could only be distinguished on the basis of a difference in patch orientation. In our analyses, we compare the pRF properties obtained using this new orientation contrast-based retinotopy (OCR) to those obtained using classic luminance contrast-based retinotopy (LCR). Specifically, in higher order cortical visual areas such as LO, our novel approach resulted in non-trivial reductions in estimated population receptive field size of around 30%. A set of control experiments confirms that the most plausible cause for this reduction is that OCR mainly drives neurons sensitive to orientation contrast. We discuss how OCR - by limiting receptive field scatter and reducing BOLD displacement - may result in more accurate pRF localization as well. Estimation of neuronal properties is crucial for interpreting cortical function. Therefore, we conclude that using our approach, it is possible to selectively target particular neuronal

Lubricant Test Methods for Sheet Metal Forming

DEFF Research Database (Denmark)

Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

2008-01-01

appearing in different sheet forming operations such as stretch forming, deep drawing, ironing and punching. The laboratory tests have been especially designed to model the conditions in industrial production. Application of the tests for evaluating new lubricants before introducing them in production has......Sheet metal forming of tribologically difficult materials such as stainless steel, Al-alloys and Ti-alloys or forming in tribologically difficult operations like ironing, punching or deep drawing of thick plate requires often use of environmentally hazardous lubricants such as chlorinated paraffin...... oils in order to avoid galling. The present paper describes a systematic research in the development of new, environmentally harmless lubricants focusing on the lubricant testing aspects. A system of laboratory tests has been developed to study the lubricant performance under the very varied conditions...

Study on Explosive Forming of Aluminum Alloy

Directory of Open Access Journals (Sweden)

H Iyama

2016-09-01

Full Text Available Now, the aluminum alloy is often used as auto parts, for example, body, engine. For example, there are the body, a cylinder block, a piston, a connecting rod, interior, exterior parts, etc. These are practical used the characteristic of a light and strong aluminum alloy efficiently. However, although an aluminum alloy is lighter than steel, the elongation is smaller than that. Therefore, in press forming, some problems often occur. We have proposed use of explosive forming, in order to solve this problem. In the explosive forming, since a blank is formed at high speed, a strain rate effect becomes large and it can be made the elongation is larger. Then, in order to clarify this feature, we carried out experimental research and numerical analysis. In this paper, these contents will be discussed.

Test Guide for ADS-33E-PRF

Science.gov (United States)

2008-07-01

LIMITED DOCUMENTS, DESTROY BY ANY METHOD THAT WILL PREVENT DISCLOSURE O F CONTENTS OR RECONSTRUCTION O F THE DOCUMENT. DISCLAIMER THE FINDINGS IN...meeting one or both of these parameters. Such a demonstration should include high workload IFR tasks such as the MTEs in 3.1 1.20 through 3.1 1.23...failure and then begin to take proper corrective action. For divided attention operations (e.g. single pilot IFR ), it is suggested that the 1.5 second

Blending Octane Number of Ethanol in HCCI, SI and CI Combustion Modes

KAUST Repository

Waqas, Muhammad

2016-10-17

The effect of ethanol blended with three FACE (Fuels for Advanced Combustion Engines) gasolines, I, J and A corresponding to RON 70.3, 71.8 and 83.5, respectively, were compared to PRF70 and PRF84 with the same ethanol concentrations, these being 2%, 5%, 10%, 15% and 20% by volume. A Cooperative Fuel Research (CFR) engine was used to understand the blending effect of ethanol with FACE gasolines and PRFs in spark-ignited and homogeneous charge compression ignited mode. Blending octane numbers (BON) were obtained for both the modes. All the fuels were also tested in an ignition quality tester to obtain Blending Derived Cetane numbers (BDCN). It is shown that fuel composition and octane number are important characteristics of all the base fuels that have a significant impact on octane increase with ethanol. The dependency of octane number for the base fuel on the blending octane number depended on the combustion mode operated. The aromatic composition in the base fuel, effects blending octane number of the mixture, for fuels with higher aromatic content lower blending octane numbers were observed for ethanol concentration.

Blending Octane Number of Ethanol in HCCI, SI and CI Combustion Modes

KAUST Repository

Waqas, Muhammad; Naser, Nimal; Sarathy, Mani; Morganti, Kai; Al-Qurashi, Khalid; Johansson, Bengt

2016-01-01

The effect of ethanol blended with three FACE (Fuels for Advanced Combustion Engines) gasolines, I, J and A corresponding to RON 70.3, 71.8 and 83.5, respectively, were compared to PRF70 and PRF84 with the same ethanol concentrations, these being 2%, 5%, 10%, 15% and 20% by volume. A Cooperative Fuel Research (CFR) engine was used to understand the blending effect of ethanol with FACE gasolines and PRFs in spark-ignited and homogeneous charge compression ignited mode. Blending octane numbers (BON) were obtained for both the modes. All the fuels were also tested in an ignition quality tester to obtain Blending Derived Cetane numbers (BDCN). It is shown that fuel composition and octane number are important characteristics of all the base fuels that have a significant impact on octane increase with ethanol. The dependency of octane number for the base fuel on the blending octane number depended on the combustion mode operated. The aromatic composition in the base fuel, effects blending octane number of the mixture, for fuels with higher aromatic content lower blending octane numbers were observed for ethanol concentration.

Aesthetic Forms of Data Representation in Qualitative Family Therapy Research

Science.gov (United States)

Piercy, Fred P.; Benson, Kristen

2005-01-01

In this article we provide a rationale for using alternative, aesthetic methods of qualitative representation (e.g., creative writing, art, music, performance, poetry) in qualitative family therapy research. We also provide illustrative examples of methods that bring findings to life, and involve the audience in reflecting on their meaning. One…

The Factors Affecting Definition of Research Problems in Educational Technology Researches

Science.gov (United States)

Bahçekapili, Ekrem; Bahçekapili, Tugba; Fis Erümit, Semra; Göktas, Yüksel; Sözbilir, Mustafa

2013-01-01

Research problems in a scientific research are formed after a certain process. This process starts with defining a research topic and transforms into a specific research problem or hypothesis. The aim of this study was to examine the way educational technology researchers identify their research problems. To this end, sources that educational…

DownloadAccess to Information Request form

International Development Research Centre (IDRC) Digital Library (Canada)

PC Forms Inc. 834-4048

To apply for information under the Access to. Information Act, complete this form or a written request mentioning the Act. Describe the information being sought and provide any relevant details necessary to help the International. Development Research Centre (IDRC) find it. If you require assistance, refer to Info Source.

Nuclear research reactors

International Nuclear Information System (INIS)

1985-01-01

It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.) [pt

On the effects of fuel properties and injection timing in partially premixed compression ignition of low octane fuels

KAUST Repository

Naser, Nimal

2017-06-29

A better understanding on the effects of fuel properties and injection timing is required to improve the performance of advanced engines based on low temperature combustion concepts. In this work, an experimental and computational study was conducted to investigate the effects of physical and chemical kinetic properties of low octane fuels and their surrogates in partially premixed compression ignition (PPCI) engines. The main objective was to identify the relative importance of physical versus chemical kinetic properties in predicting practical fuel combustion behavior across a range of injection timings. Two fuel/surrogate pairs were chosen for comparison: light naphtha (LN) versus the primary reference fuel (PRF) with research octane number of 65 (PRF 65), and FACE (fuels for advanced combustion engines) I gasoline versus PRF 70. Two sets of parametric studies were conducted: the first varied the amount of injected fuel mass at different injection timings to match a fixed combustion phasing, and the second maintained the same injected fuel mass at each injection timing to assess resulting combustion phasing changes. Full-cycle computational fluid dynamic engine simulations were conducted by accounting for differences in the physical properties of the original and surrogate fuels, while employing identical chemical kinetics. The simulations were found to capture trends observed in the experiments, while providing details on spatial mixing and chemical reactivity for different fuels and injection timings. It was found that differences in physical properties become increasingly important as injection timing was progressively delayed from premixed conditions, and this was rationalized by analysis of mixture stratification patterns resulting from injection of fuels with different physical properties. The results suggest that accurate descriptions of both physical and chemical behavior of fuels are critical in predictive simulations of PPCI engines for a wide range of

On the effects of fuel properties and injection timing in partially premixed compression ignition of low octane fuels

KAUST Repository

Naser, Nimal; Jaasim, Mohammed; Atef, Nour; Chung, Suk-Ho; Im, Hong G.; Sarathy, Mani

2017-01-01

A better understanding on the effects of fuel properties and injection timing is required to improve the performance of advanced engines based on low temperature combustion concepts. In this work, an experimental and computational study was conducted to investigate the effects of physical and chemical kinetic properties of low octane fuels and their surrogates in partially premixed compression ignition (PPCI) engines. The main objective was to identify the relative importance of physical versus chemical kinetic properties in predicting practical fuel combustion behavior across a range of injection timings. Two fuel/surrogate pairs were chosen for comparison: light naphtha (LN) versus the primary reference fuel (PRF) with research octane number of 65 (PRF 65), and FACE (fuels for advanced combustion engines) I gasoline versus PRF 70. Two sets of parametric studies were conducted: the first varied the amount of injected fuel mass at different injection timings to match a fixed combustion phasing, and the second maintained the same injected fuel mass at each injection timing to assess resulting combustion phasing changes. Full-cycle computational fluid dynamic engine simulations were conducted by accounting for differences in the physical properties of the original and surrogate fuels, while employing identical chemical kinetics. The simulations were found to capture trends observed in the experiments, while providing details on spatial mixing and chemical reactivity for different fuels and injection timings. It was found that differences in physical properties become increasingly important as injection timing was progressively delayed from premixed conditions, and this was rationalized by analysis of mixture stratification patterns resulting from injection of fuels with different physical properties. The results suggest that accurate descriptions of both physical and chemical behavior of fuels are critical in predictive simulations of PPCI engines for a wide range of

Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

KAUST Repository

Vallinayagam, R.

2018-03-20

The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

Factors Forming Collaboration within the Knowledge Triangle of Education, Research and Innovation

Science.gov (United States)

Zascerinska, Jelena; Ahrens, Andreas; Bassus, Olaf

2009-01-01

A proper combination of education, research and innovation is provided by varied cooperative networks. However, the success of collaboration within a multicultural environment requires that the key factors enabling synergy between education, research and innovation have to be considered. Aim of the following paper is to identify and to analyze…

Researcher Story: Stuttering

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Leucocyte-rich and platelet-rich fibrin for the treatment of bisphosphonate-related osteonecrosis of the jaw: a prospective feasibility study.

Science.gov (United States)

Kim, Jin-Woo; Kim, Sun-Jong; Kim, Myung-Rae

2014-11-01

Our aim was to assess the feasibility of using leucocyte-rich and platelet-rich fibrin (L-PRF) for the treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in a single group study. After treatment with L-PRF, the response of each patient was recorded 1 month and 4 months postoperatively. Further assessments were made of the site, stage, concentration of c-terminal crosslinked telopepide of type 1 collagen, and actinomycosis. Among the total of 34 patients, 26 (77%) showed complete resolution, 6 (18%) had delayed resolution, and 2 (6%) showed no resolution. There was a significant association between the response to treatment and the stage of BRONJ (p=0.002) but no other significant associations were detected. This study has shown that it is feasible to use L-PRF for the treatment of BRONJ, but the effectiveness cannot be judged with this study design. Randomised prospective trials are needed to confirm this. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Revascularization of Immature Necrotic Teeth: Platelet rich Fibrin an Edge over Platelet rich Plasma

Directory of Open Access Journals (Sweden)

Neelam Mittal

2012-03-01

Full Text Available Introduction: Revascularization is one such entity that has found its clinical application in the field of endodontics for the manage-ment of immature permanent necrotic teeth. The protocols for revascularization of such teeth focus especially on delivery of stem cells and scaffolds in a nonsurgical manner rather than concentrated growth micro molecules.The hypothesis: This article proposes the role of platelet concentrates such as platelet rich fibrin (PRF and platelet rich plasma (PRP in accelerating the regenerative process in such teeth. PRF unlike PRP is associated with slow, continuous and substantial re-lease of morphogens. It is hypothesized further if PRF instead of PRP when placed through immature apices in an orthograde manner can open newer gates for fast and controlled growth in young, ne-crotic, non-infected teeth.Evaluation of the hypothesis: Enhancement of the healing kinetics can be evaluated by change in size of periapical radiolucency, thickness of the dentinal walls, root elongation and apical closure compared between preoperative and postoperative standardized two dimensional/three dimensional radiographs taken on regular follow ups.

Controllable forms of natural background radiation

International Nuclear Information System (INIS)

1988-03-01

RENA is a research programm into the controllable forms of natural background radiation, which cover the activities originating from the naturally occurring radionuclides enhanced by human intervention. In the RENA-program emphasis lays upon the policy aspects of environmental-hygienic, economical and governmental character. (H.W.). 15 refs.; 2 tabs

Identifying and Prioritizing Gaps in Neuroendocrine Tumor Research: A Modified Delphi Process With Patients and Health Care Providers to Set the Research Action Plan for the Newly Formed Commonwealth Neuroendocrine Tumor Collaboration

Directory of Open Access Journals (Sweden)

Eva Segelov

2017-08-01

Full Text Available Purpose: Neuroendocrine tumors (NETs are a diverse group of malignancies that pose challenges common to all rare tumors. The Commonwealth Neuroendocrine Tumor Collaboration (CommNETS was established in 2015 to enhance outcomes for patients with NETs in Canada, Australia, and New Zealand. A modified Delphi process was undertaken involving patients, clinicians, and researchers to identify gaps in NETs research to produce a comprehensive and defensible research action plan. Methods: A three-round modified Delphi process was undertaken with larger representation than usual for medical consensus processes. Patient/advocate and health care provider/researcher expert panels undertook Round 1, which canvassed 17 research priorities and 42 potential topics; in Round 2, these priorities were ranked. Round 3 comprised a face-to-face meeting to generate final consensus rankings and formulate the research action plan. Results: The Delphi groups consisted of 203 participants in Round 1 (64% health care providers/researchers, 36% patient/advocates; 52% Canadian, 32% Australian, and 17% New Zealander, of whom 132 participated in Round 2. The top eight priorities were biomarker development; peptide receptor radionuclide therapy optimization; trials of new agents in advanced NETs; functional imaging; sequencing therapies for metastatic NETs, including development of validated surrogate end points for studies; pathologic classification; early diagnosis; interventional therapeutics; and curative surgery. Two major areas were ranked significantly higher by patients/advocates: early diagnosis and curative surgery. Six CommNETS working parties were established. Conclusion: This modified Delphi process resulted in a well-founded set of research priorities for the newly formed CommNETS collaboration by involving a large, diverse group of stakeholders. This approach to setting a research agenda for a new collaborative group should be adopted to ensure that research plans

Identifying and Prioritizing Gaps in Neuroendocrine Tumor Research: A Modified Delphi Process With Patients and Health Care Providers to Set the Research Action Plan for the Newly Formed Commonwealth Neuroendocrine Tumor Collaboration.

Science.gov (United States)

Segelov, Eva; Chan, David; Lawrence, Ben; Pavlakis, Nick; Kennecke, Hagen F; Jackson, Christopher; Law, Calvin; Singh, Simron

2017-08-01

Neuroendocrine tumors (NETs) are a diverse group of malignancies that pose challenges common to all rare tumors. The Commonwealth Neuroendocrine Tumor Collaboration (CommNETS) was established in 2015 to enhance outcomes for patients with NETs in Canada, Australia, and New Zealand. A modified Delphi process was undertaken involving patients, clinicians, and researchers to identify gaps in NETs research to produce a comprehensive and defensible research action plan. A three-round modified Delphi process was undertaken with larger representation than usual for medical consensus processes. Patient/advocate and health care provider/researcher expert panels undertook Round 1, which canvassed 17 research priorities and 42 potential topics; in Round 2, these priorities were ranked. Round 3 comprised a face-to-face meeting to generate final consensus rankings and formulate the research action plan. The Delphi groups consisted of 203 participants in Round 1 (64% health care providers/researchers, 36% patient/advocates; 52% Canadian, 32% Australian, and 17% New Zealander), of whom 132 participated in Round 2. The top eight priorities were biomarker development; peptide receptor radionuclide therapy optimization; trials of new agents in advanced NETs; functional imaging; sequencing therapies for metastatic NETs, including development of validated surrogate end points for studies; pathologic classification; early diagnosis; interventional therapeutics; and curative surgery. Two major areas were ranked significantly higher by patients/advocates: early diagnosis and curative surgery. Six CommNETS working parties were established. This modified Delphi process resulted in a well-founded set of research priorities for the newly formed CommNETS collaboration by involving a large, diverse group of stakeholders. This approach to setting a research agenda for a new collaborative group should be adopted to ensure that research plans reflect unmet needs and priorities in the field.

The Form of HWID Theory